UK PubMed Central (United Kingdom)

Mice lacking Kv1.1 Shaker-like potassium channels encoded by the Kcna1 gene exhibit severe seizures and die prematurely. The channel is widely expressed in...Full Text Available

Science.gov (United States)

Lanthanide-ion doped oxide nanoparticles were functionalized for use as fluorescent biological labels. These nanoparticles are synthesized directly in water which facilitates their functionalization, and are very photostable without emission intermittency. Nanoparticles functionalized with guanidinium groups act as artificial toxins and specifically target sodium channels. They are individually detectable in cardiac myocytes, revealing a heterogeneous distribution of sodium channels. Functionalized oxide nanoparticles appear as a novel tool particularly well adapted to long-term single-molecule tracking.

Science.gov (United States)

We present a quantum secure direct communication scheme achieved by swapping quantum entanglement. In this scheme a set of ordered Einstein-Podolsky-Rosen (EPR) pairs is used as a quantum information channel for sending secret messages directly. After insuring the safety of the quantum channel, the sender Alice encodes the secret messages directly by applying a series local operations on her particle sequences according to their stipulation. Using three EPR pairs, three bits of secret classical information can be faithfully transmitted from Alice to remote Bob without revealing any information to a potential eavesdropper. By both Alice and Bob's GHZ state measurement results, Bob is able to read out the encoded secret messages directly. The protocol is completely secure if perfect quantum channel is used, because there is not a transmission of the qubits carrying the secret message between Alice and Bob ...

British Library Electronic Table of Contents (United Kingdom)

This study aimed to explore the impact of perceived service quality and self-concept on consumer attitude and purchase process using channel type (physical and Internet) as a segmentation variable. From the perspective of consumer behaviour, this study attempted to estimate a relational model and perform an empirical validation using female cosmetics and skincare products as an example. It was discovered that the influence of perceived service quality and self-concept on consumer attitude, purchase intention and behaviour, satisfaction, and loyalty varied with channel type. The analysis result revealed that physical stores presented higher levels of agreement with all research perspectives than Internet stores. However, only two relational paths have a higher influencing effect in physical...

International Nuclear Information System (INIS)

The sensitivity of the primary circuit material was examined at the Mochovce and Dukovany NPPs. No significant sensitivity of the base material or the weld metal to the initiation of corrosion cracking was observed. Thermal aging was found to accelerate significantly the corrosion fatigue kinetics in the material of the heat affected zone. The threshold values of the double amplitudes of the stress intensity factor were below 8 MPa/m"2 for the materials examined, with a cycle asymmetry coefficient of 0.65. The tests revealed no appreciable sensitivity to general corrosion, pitting, or intergranular corrosion. (J.B.). 7 tabs., 26 figs., 11 refs.

CERN Document Server

In this paper, we extend the diversity and multiplexing tradeoff (DMT) analysis from point-to-point channels to cellular systems to evaluate the impact of inter-cell interference on the system reliability and efficiency. Fundamental tradeoff among diversity order, multiplexing gain and inter-cell interference intensity is characterized to reveal the capability of multiple antennas in cellular systems. And the detrimental effects of the inter-cell interference on the system performance of diversity and multiplexing is presented and analyzed.

International Nuclear Information System (INIS)

Focused-ion beam (FIB) milling provides rapid fabrication of individual cylindrical submicrometer channels with reproducible dimensions (#+-#5% diameters) through 8-#mu#m thick poly(methylmethacrylate) (PMMA) films. PMMA films are spincast on sacrificial Si carriers and sputter-coated with Au before the 30-kV gallium FIB milling process. By adding a trace amount of poly(ethyleneoxide) and poly(dimethylsiloxane) to the PMMA solution before casting, the films can be released for subsequent mounting in microfluidic devices to create hybrid microfluidic-nanofluidic multilevel architectures. In situ FIB sectioning demonstrates the smooth cylindrical surface within the pore. Placing a milled film in contact with an aqueous fluorescein solution fills the channel by capillary action, as verified by confocal fluorescence microscopy. Confocal fluorescence of dyed films reveals that the pores span the thickness of the PMMA film. Small ...

British Library Electronic Table of Contents (United Kingdom)

In this work, a three-dimensional multiphase non-isothermal model incorporated with a capillary-extended sub-model in gas channels is used to investigate the coupled phenomena of water and thermal transport in proton exchange membrane fuel cells. Distributions of water and temperature along the flow path in the channel are highlighted and the pros and cons of various operating temperatures are elaborated. In addition, this work also sheds light on the impacts of temperature variations of bipolar plates induced by non-uniform cooling conditions, which have been overlooked by most previous works. An important phenomenon of water distribution, dry-out at inlets and flooding at outlets (DIFO), is observed and this non-uniform distribution is revealed to be greatly influenced by the operating t...

British Library Electronic Table of Contents (United Kingdom)

Dissolved microcystins (MCs) are regularly present in water dominated by microcystin-producing, bloom-forming cyanobacteria. In vitro experiments with environmentally feasible concentrations (5 ? 10?7 M) of the three most common microcystins, MC-LR, MC-RR, and MC-YR, revealed that they influence the metabolism of different representative phytoplanktons. At light intensities that are close to the cyanobacterial bloom environment (50??mol m?2 s?1), they produce morphological and physiological changes in both microcystin-producing and -nonproducing Microcystis aeruginosa strains and also have similar effects on the green alga Scenedesmus quadricauda that is frequently present in cyanobacterial blooms. All three microcystin variants tested induce cell aggregation, increase in cell volume, and ...

Energy Technology Data Exchange (ETDEWEB)

The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum ...

International Nuclear Information System (INIS)

Sesame varieties/genotypes showed a good response to radiation with gamma rays and treatments with EMS. In M_1 both gamma rays and EMS influenced germination, seedling height, survival of plants and pollen fertility/sterility, producing deleterious effects on these characters. Compared to black seeded genotypes, white seeded ones are more susceptible to radiation. Both gamma rays and EMS produced various types of morphological variations in M_2 generation. These were dwarf plant mutants, mottled and fleshy leaved mutants (sterile), fasciated stem, flower colour, altered phyllotaxy, early, uniculm, capsule size variations, multiple capsule/leaf axil, seed coat colour variations, indehiscent and semi-indehiscent type mutants. Moreover, studies on quantitative characters including seed yield revealed the induction of mutants in both positive and negative directions for such traits which made a good scope of selection of ...

Science.gov (United States)

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International Nuclear Information System (INIS)

The operation and safety of both fossil-fuel and nuclear power stations depend on adequate cooling of the thermal source involved. This is usually accomplished using liquid coolants that are forced through the high temperature regions by a pumping system; this fluid then transports the thermal energy to another section of the power station. However, fluids that undergo boiling during this process create vapor that can be detrimental, and influence safe operation of other system components. The behavior of this vapor, or void, as it is generated and transported through the system is critical in predicting the operational and safety performance. This study uses two advanced penetrating radiation techniques, Real Time Neutron Radiography (RTNR), and High Speed X-Ray Tomography (HS-XCT), to examine void generation and transport behavior in a flow boiling system. The geometries studied were tube side flow boiling in a cylindrical configuration, and a similar flow ...

International Nuclear Information System (INIS)

A homogeneous turbulent mixing of coolant flows with different temperatures at the fuel assembly inlets is an important requirement to minimize hot spots in a fuel assembly of a High Performance Light Water Reactor (HPLWR). Therefore, the mixing chamber between lower core plate, flow adjuster and the mixing chamber within the cluster foot piece diffuser have been investigated using the Computational Fluid Dynamics (CFD)-code Fluent 6.1 and its implemented k-#epsilon# model. The previously presented 3D-CAD-geometry has been simplified using Gambit 2.1.2 and consists of various inlet and outlet tubes or channels in the foot piece bottom plate, the lower core plate and the flow adjuster establishing the boundaries of two consecutive mixing chambers. The temperature distribution at the inlet of the sub-channels of the cluster fuel assemblies is presented. It reveals temperature variations at the coolant inlet of the nine fuel ...

International Nuclear Information System (INIS)

Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca"2"+ channel (SOCC)-mediated Ca"2"+ entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, indicating a major role ...

British Library Electronic Table of Contents (United Kingdom)

A stable BSA blocking poly(dimethylsiloxane) (PDMS) microchannel was prepared based on in situ synthesized PDMS-gold nanoparticles composite films. The modified microchip could successfully suppress protein adsorption. The assembly was followed by contact angle, charge-coupled device (CCD) imaging, electroosmotic flow (EOF) measurements and electrophoretic separation methods. Contact angle measurements revealed the coated surface was hydrophilic, water contact angle for coated chips was 45.2^o compared to a water contact angle for native PDMS chips of 88.5^o. The coated microchips exhibited reproducible and stable EOF behavior. With FITC-labeled myoglobin incubation in the coated channel, no fluorescence was observed with CCD image, and the protein exhibited good electrophoretic effect in ...

CERN Document Server

The controlled growth of nanowires (NWs) with dimensions comparable to the Fermi wavelengths of the charge carriers allows fundamental investigations of quantum confinement phenomena. Here, we present studies of proximity-induced superconductivity in undoped Ge/Si core/shell NW heterostructures contacted by superconducting leads. By using a top gate electrode to modulate the carrier density in the NW, the critical supercurrent can be tuned from zero to greater than 100 nA. Furthermore, discrete sub-bands form in the NW due to confinement in the radial direction, which results in stepwise increases in the critical current as a function of gate voltage. Transport measurements on these superconductor-NW-superconductor devices reveal high-order (n = 25) resonant multiple Andreev reflections, indicating that the NW channel is smooth and the charge transport is highly coherent. The ability to create and control coherent superconducting ordered states ...

International Nuclear Information System (INIS)

Dispersed flow film boiling is the heat transfer regime that occurs at high void fractions in a heated channel. The way this transfer mode is modelled in the NRC computer codes (RELAP5 and TRAC) and the validity of the assumption and empirical correlations used is discussed. An extensive review of the theoretical and experimental work related with heat transfer to highly dispersed mixtures reveals the basic deficiencies of these models: the investigation refers mostly to the typical conditions of low rate bottom reflooding, since the simulation of this physical situation by the computer codes has often showed poor results. The alternative models that are available in the literature are reviewed, and their merits and limits are highlighted. The modification that could improve the physics of the models implemented in the codes are identified. (author) 13 figs., 123 refs.

Energy Technology Data Exchange (ETDEWEB)

SIMS measurements revealed that high energy boron-implantation causes transient enhanced diffusion (TED) of a shallow dopant profile due to Si interstitials even for a relatively low dose of {approximately}2E13cm{sup {minus}2}. By systematic analysis, it is found that this anomalous diffusion is most significant in 700--800 C annealing, and it takes place in the initial stage (less than 30 sec for 800 C) of annealing. Moreover, this anomalous diffusion is more considerable than the enhanced diffusion during oxidation (OED) in practical device fabrication processes. It is found that rapid thermal annealing (RTA) at 1,000--1,100 C is effective for suppressing the transient enhanced diffusion and realizing a shallow channel profile for deep sub-micron devices.

British Library Electronic Table of Contents (United Kingdom)

A WO3/TiO2 composite, hollow-sphere photocatalyst with average diameter of 320nm and shell thickness of 50nm was successfully prepared using a template method. UV-vis diffuse reflectance spectra illustrated that the main absorption edges of the WO3/TiO2 hollow spheres were red-shifted compared to the TiO2 hollow spheres, indicating an extension of light absorption into the visible region of the composite photocatalyst. The WO3 and TiO2 phases were confirmed by X-ray diffraction analysis. BET isotherms revealed that the specific surface area and average pore diameter of the hollow spheres were 40.95m^2/g and 19nm, respectively. Photocatalytic experiments indicate that 78% MB was degraded by WO3/TiO2 hollow spheres under visible light within 80min. Under the same conditions, only 24% MB can ...

Science.gov (United States)

We prepared submicron-scale spherical hollow particles of anatase TiO2 by using a polystyrene-bead template. The obtained particles were very uniform in size, with a diameter of 490 nm and a shell thickness of 30 nm. The Brunauer-Emmett-Teller surface area measurements revealed a large value of 70 m2/g. The photocatalytic property was investigated by the complete decomposition of gaseous isopropyl alcohol under UV irradiation. It was indicated that the activity of the hollow spheres was 1.8 times higher than that of the conventional P25 TiO2 nanoparticles with a diameter of 30 nm. Furthermore, we fabricated a dye-sensitized solar cell (DSC) using an electrode of the TiO2 hollow spheres, and examined the photovoltaic performance under simulated sunlight. Although the per-area efficiency was rather low (1.26%) because of a low area density of TiO2 on the electrode, the per-weight efficiency was 2.5 times higher than those of ...

DEFF Research Database (Denmark)

Udgivelsesdato: APR

Science.gov (United States)

Not Available

DEFF Research Database (Denmark)

Udgivelsesdato: DEC 1

International Nuclear Information System (INIS)

A high resolution Compton telescope has been identified by the Gamma Ray Astronomy Program Working Group (GRAPWG) as the highest priority major mission in gamma ray astrophysics following GLAST. This mission should provide 25-100 times improved sensitivity, relative to CGRO and INTEGRAL, for MeV gamma ray lines. It must have good performance for narrow and broad lines and for discrete and diffuse emissions. Several instrumental approaches are being pursued to achieve these goals. We discuss issues relating to this mission including alternative detector concepts, instrumental configurations, and background reduction techniques. We have pursued the development of position-sensitive solid-state detectors (Ge, Si) for a high spectral resolution Compton telescope mission. A #approx#1 m2 germanium Compton telescope of position-sensitive germanium detectors was the basis for one of the GRAPWG concepts. Preliminary Monte Carlo estimates for the ...

Energy Technology Data Exchange (ETDEWEB)

The Permian San Andres Formation of late Leonardian-early Guadalupian age is a significant hydrocarbon producer and crops out over a large area in south-central New Mexico. However, since its definition in 1909, the age and depositional environment of this unit have been questioned. In 1971 in Pecos County, Vincent Kelly divided the unit into three members: Rio Bonito, Bonney Canyon, and Fourmile Draw. The lowest member, although named for the Rio Bonito, has a type section designated at Sunset along U.S. Highway 70/380. Two miles east of Sunset, near Riverside, on the Rio Bonito, the Rio Bonito Member is exposed in a long series of roadcuts. Petrographic investigation of these rocks reveals an alternating sequence of high to low-energy intertidal to subtidal facies marked by oolitic and fossiliferous dolocalcarenite interbedded with dolomitic mudstone. The unit has been recrystallized and stylolites are abundant, as is dolomite and nodular mosaic anhydrite. These ...

Energy Technology Data Exchange (ETDEWEB)

The microstructure of Al/{alpha}-Al{sub 2}0{sub 3} composites made by infiltrating Al into dense mullite preforms has been characterized using transmission electron microscopy. Observations revealed that the formation of the Al/Al{sub 2}0{sub 3} composites involves three stages. Initially, Al infiltrates into a dense mullite preform through grain boundary diffusion, and reacts with mullite at grain boundaries to form a partial reaction zone. Then, a complete reaction takes place in the reaction region between the partial reaction zone and the full reaction zone to convert the dense mullite preform to a composite of {alpha}-Al{sub 2}0{sub 3} (matrix) and an Al-Si phase (thin channels). Finally, the reduced Si from the reaction diffuses out of the Al/Al{sub 2}0{sub 3} composite through the metal channels, whereas Al from the molten Al pool is continuously drawn to the reaction region until the mullite preform is consumed or ...

International Nuclear Information System (INIS)

The compositions of passive films formed on Fe-17Fr-13Ni (at. %) and Fe-18.5Cr-14Ni-1.5Mo (100) single crystals have been determined and the structure of the alloy under the film has been investigated. The alloys were passivated in 0.05M H_2SO_4 at 250 mV/SHE for 30 min. The oxygen content was measured by nuclear microanalysis using the "1"6O(d,p) "1"7O* reaction. The oxygen content in the passive film is similar for the two alloys and equal to (12#+-#2) 10"1"5 O/cm"2. The cationic compositions of the passive films have been determined by "4He channeling at two incident beam energies: 0.8 and 2.0 MeV. For the two alloys studied, a total cation content of (5#+-#2)10"1"5 at/cm"2 is found in the passive films. The corresponding thickness is about 12 A. There is an excess of oxygen, which can be attributed to the presence of hydroxyls and sulfate. A strong chromium enrichment is found in the passive film formed on both alloys: chromium represents about 50% of the ...

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

Single-channel currents from acetylcholine receptor channels of garter snake neuromuscular junctions were recorded using the patch-clamp technique. Low concentrations of acetylcholine or carbamylcholine...Full Text Available

International Nuclear Information System (INIS)

"2"7Al and "2"9Si solid-state NMR spectra and X-ray diffraction (XRD) patterns were obtained for #alpha#-SiAlON powders prepared by combustion synthesis, according to which the phase transformation and structure evolution of #alpha#-SiAlON were studied. It was found that in #alpha#-SiAlON "2"9Si chemical shift values (-48 < #delta# _S_i < -47) were close to those in #beta#-Si_3N_4 and #alpha#-Si_3N_4, indicating that Si atoms kept SiN_4 coordination to a large extent in #alpha#-SiAlON despite the presence of O atoms. Dissimilarly, "2"7Al chemical shift values in #alpha#-SiAlON deviated clearly from that corresponding to AlN_4 coordination (#delta# _A_l #approx# 112) and occurred in a range from #delta# _A_l 95.5 to 99.9, which should be assigned to tetrahedral AlO _xN_4_-_x (0 #<=# x #<=# 4) coordination. The broadening effect of AlO _xN_4_-_x peaks was noticed, which was suggested to induced by slight dispersion of #alpha#-SiAlON compositions. "2"7Al resonances assigned to ...

International Nuclear Information System (INIS)

Homologous and heterologous arterial segments were implanted in Fisher rats subcutaneously for the purpose of examining the antibody titer of the recipients' serum after implantation by means of the immune-adherence hemagglutination method. The antibody titer after implantation both of homologous and heterologous grafts decreased to 1/8 by 2.0 million (M) rads irradiation of high voltage cathode rays. The results suggested that high voltage cathode ray irradiation was not enough for heterologous graft to suppress its tissue reaction. Homografts taken from dogs 3 or 6 hours after sacrifice were irradiated with 2.0 M rads and transplanted in canine carotid artery using the technic of end-to-end anastomosis. Angiograms 6 months after operation revealed excellent patency rate in all the grafts of 28 dogs. furthermore, findings of the grafts from 1 week to 5 years after operation on scanning and transmission electron microscopies were evaluated. Clinical application of ...

UK PubMed Central (United Kingdom)

PURPOSETo examine the mechanisms of ischemic preconditioning (IPC) related to the opening of mitochondrial KATP (mKATP) channels in the retina.Full Text Available

International Nuclear Information System (INIS)

We have obtained radial velocities for 69 stars in the globular cluster M2 (NGC 7089). M2's rotation axis is, within sizeable uncertainties, perpendicular to the major axis determined by the flattening. The ratio of rotational to random kinetic energy agrees with that predicted from the ellipticity assuming an oblate figure and an isotropic velocity-dispersion tensor. We have fitted King-Michie models to determine M2's mass, the exponent of an assumed power-law mass function, and the anisotropy radius. The most significant sources of uncertainty in the modeling are the velocity dispersion, the distance, and the mass-luminosity relation for the cluster stars. The models favor mass functions similar to or shallower than the Salpeter initial-mass function and a moderate amount of velocity anisotropy.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

1977. USSR Beloshitsky, VV Kumakhov, MA Wedell, R. Moskovskij

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

... bf3 counters data multi-channel analyzers multivibrators neutron spectrometers

International Nuclear Information System (INIS)

... Ulf G. Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik,

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Not Available

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This paper investigates the anodic behavior of steels 12Kh18N10T, 10Kh17N13M2T, 08Kh22N6T, and 08Kh21N6M2T in 92% sulfuric acid. The aim of the study was to determine the parameters for anodic protection of shell-and-tube coolers. Results of the study are presented.

Science.gov (United States)

As both computer and mobile phone reach nearly ubiquity in the U.S. market, the slow uptake of mobile video, in contrast to the thriving usage of PC-based video, warrants a deeper understanding of user-oriented factors contributing to the two diffusion paths. Unlike the majority of existing diffusion research practices, the dissertation examines the differences between mobile and PC video diffusion patterns through the lenses of user-oriented influences in the user-technology relationship. Built upon the established adoption user group classification, the research is informed by the Uses and Gratification theory, the Social Technical theory, and the Technical Affordance perspective. These synergistic theoretical arguments share the recognition of the role of user in the dynamic, usually socially intertwined user-technology interactions. The key research questions that the dissertation sets out to answer include: Does the importance of quality of viewing experience in adoption ...

Energy Technology Data Exchange (ETDEWEB)

In the development of high performance heat transfer surface on a compact heat exchanger, it was clarified that how reattachment point heat transfer and fluid flow are affected by channel width, at the same time, an evaluation of heat transfer performance and an investigation of optimum channel width were carried out. The channel system used in the experiment is as follows; (1) blow-off type with rectangular section channel, (2) span length of 200 mm, (3) wave length (pitch) of 80 mm, and (4) channel length of 12.5 wave length. The channel Reynolds number was set at about 10/sup 4/ which is relatively higher than the current studies. The results of the experiment were summarized as follows. (1) The channel width H has relevance to the phase difference between the fluid flow in cone portion of main stream and wave shape, the flow patterns are ...

Science.gov (United States)

The local heat transfer coefficient distribution of a square channel with two opposite ribbed walls was determined. The square channel was connected to a sudden contraction entrance in order to simulate the inlet condition of the turbine blade cooling passages. The test channel was heated by thin stainless steel foils with a thickness of 0.000025 m, and instrumented with 180 thermocouples. The brass ribs of a square cross-section were glued periodically, in line, onto the top and bottom walls of the foil-heated channel in patterns to achieve the desired spacing and angle-of-attack. The local heat transfer coefficients on the smooth side and the ribbed side walls, at the channel entrance and the downstream regions, were measured for eight rib configurations and three Reynolds numbers (Re = 10,000, 30,000, and 60,000).

International Nuclear Information System (INIS)

The effect of in vitro and in vivo administration of ethanol on the binding of "3"5S-t-butyl-bicyclophosphorothionate ("3"5S-TBPS) to cortical brain membranes of C57B1 mice was investigated using KCl (100 mM) containing assay media. The in vitro addition of ethanol produced a dose-dependent inhibition of basal "3"5S-TBPS binding. In the presence of chloride ions, GABA and pentobarbital had a biphasic action (stimulation followed by inhibition) on "3"5S-TBPS binding, whereas diazepam only stimulated the binding. Ethanol reduced the stimulatory effects of GABA and pentobarbital in a dose-dependent manner, but had no effect on the enhancement of "3"5S-TBPS binding produced by diazepam. "3"5S-TBPS binding to cortical brain membranes was inhibited by the putative Cl"- channel blocking agent DIDS. This inhibitory action of DIDS was significantly, and dose-dependently reduced by ethanol (#<=# 100 mM ethanol). Chronic ethanol ingestion in vivo, which produced tolerance ...

Energy Technology Data Exchange (ETDEWEB)

This study resumes the discovery of an excess of actinium 227 found around by EL4 nuclear reactor actually in dismantling. The search for the origin of this excess revealed a real inquiry of investigation during three years. Because a nuclear reactor existed in this area a particular attention will have concerned this region. The doubt became the line of conduct to find the answer to the human or natural origin of this excess. Finally and against any evidence, it appears that the origin of this phenomenon was natural, consequence of the particular local geology. The detail of the different investigations is given: search of a possible correlation with the composition of elevations constituent of lanes, search (and underlining) of new sites in the surroundings of the Rusquec pond and the Plouenez station, study of the atmospheric deposits under winds of the nuclear power plant and in the east direction, search of a possible relationship with the gaseous effluents of ...

International Nuclear Information System (INIS)

Since the first commercial operation in 1983, Wolsung unit 1 has experienced several aging phenomena, especially in pressure tubes and feeder pipes. In case of pressure tubes, in-service inspections (ISI) revealed that a major portion of inspected tubes was in contact with calandria tubes. The likelihood of blister formation was a safety concern because it is a potential threat to pressure tube integrity. Wolsung unit 1 was, therefore, subjected to the SLAR (Spacer Location And Reposition) work to separate the contacted pressure tubes from calandria tubes. In this paper, experience of in-service inspection to the pressure tubes will be discussed including the irradiation creep elongation and CIGAR (Channel Inspection and Gauging Apparatus for Reactors) examination of pressure tubes. On the other hand, the problem of wall thinning in the feeder pipes became of great concern since 1996. Inspections, in compliance with CSA N285.4, were conducted ...

Science.gov (United States)

The epileptogenic and neurodegenerative effects of gamma-dendrotoxin, from Dendroaspis angusticeps, a specific blocker of a non-inactivating, voltage-sensitive K+ channel, were studied after focal injection into one dorsal hippocampus in rats pretreated with CGP040116, a N-methyl-D-aspartate (NMDA) receptor antagonist, and in rats bearing a monolateral surgical lesion of the Schaffer collaterals whose terminals originate from CA3 pyramids and release glutamate in the CA1 hippocampal area. Administration of 35 pmol gamma-dendrotoxin elicited in all of the treated animals (n=8) bilateral EEG discharges and damage to the hippocampal formation. Quantitation of the damage revealed significant bilateral neuronal cell loss in the CA1, CA3 and CA4 pyramidal cell layers. The lowest dose (0.35 pmol; n=4) of the toxin used did not affect EEG activity and failed to cause significant hippocampal cell loss whereas the 3.5 pmol (n=6) dose caused EEG seizures ...

Energy Technology Data Exchange (ETDEWEB)

The detailed sequence stratigraphic analysis of the siliciclastic-dominated Late Cretaceous sediments (Aren Sandstone and Garumnian red beds, south central Pyrenees, Spain) reveals the repeating disposition of critical elements and controlling mechanisms of cycles and sequences. Our approach integrates (a) hierarchy of unconformity-bounded units, (b) physical expression of boundaries traceable from the continent to the basin, (c) featuring facies and depositional systems, (d) well log and seismic expression, and (e) driving basing-filling mechanisms. A comparison to other active basins is suggested in order to prove the validity beyond the regional scale. Four basin-wide transgressive facies cycles were identified and interpreted as third-order units. The transgressive phase of each cycle is represented by mixed shelf deposits, while regressive periods consists of complex delta systems. The cycles are composed within their regressive phase of fourth-order ...

Energy Technology Data Exchange (ETDEWEB)

Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a ...

UK PubMed Central (United Kingdom)

Transient receptor potential (TRP) ion channels have been implicated in detecting chemical, thermal and mechanical stimuli in organisms ranging from mammals to Caenorhabditis elegans....Full Text Available

UK PubMed Central (United Kingdom)

Electrophysiological events are of central importance during the phagocyte respiratory burst, because NADPH oxidase is electrogenic and voltage sensitive. We investigated the recent suggestion that...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The background for the project of a solar-powered aircraft, designed and built by Dr. Paul McCready of California, is reported with details on the aircraft design and its flight across the English Channel.

UK PubMed Central (United Kingdom)

A parallel bundle of transmembrane (TM) alpha-helices surrounding a central pore is present in several classes of ion channel, including the nicotinic acetylcholine receptor (nAChR). We have modeled...Full Text Available

UK PubMed Central (United Kingdom)

Each heartbeat requires precisely orchestrated action potential propagation through the myocardium achieved by coordination of about a million ion channels on the surface of each cardiomyocyte....Full Text Available

UK PubMed Central (United Kingdom)

A two-channel optical system has been developed to provide spatially resolved simultaneous imaging of singlet molecular oxygen (¹O₂) phosphorescence and photosensitizer (PS) fluorescence...Full Text Available

UK PubMed Central (United Kingdom)

Large-conductance voltage- and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet...Full Text Available

Science.gov (United States)

Various measurement tools that are used in chaos theory were applied to analyze two-phase pressure signals with the objective of identifying and interpreting flow pattern transitions for two-phase flows in a small, horizontal rectangular channel. These me...

UK PubMed Central (United Kingdom)

Na⁺ channels are often spliced but little is known about the functional consequences of splicing. We have been studying the regulation of Na⁺ current inactivation in an...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Leaf litterfall, litter decomposition and nutrient return through litterfall of three dominant species, i.e. Quercus serrata, Schima wallichi and Lithocarpus dealbata were studied in different months throughout the year to assess the input and release of nutrient in the forest soil of a sub-tropical mixed oak forest of Manipur, northeastern India. Oaks in northeastern region of India are economically important species for the production of Tasar silk. The monthly litterfall ranged from 25.6 g?m?2 (July) to 198.0 g?m?2 (February) and annual litterfall was 1093.8g?m?2 in the forest site. At initial month (on November 3), the concentrations of N and C were the highest in L. dealbata, followed by Q. serrata and lowest in S. wallichi, whereas lignin and cellulose concentrations at initial month...

CERN Document Server

We find an exact analytic solution for the time evolution of a three Dirac neutrino system adiabatically oscillating in matter, constructing explicitly the relevant 3\\times 3 mixing matrix in matter. Using this result we investigate the solar neutrino data in a scenario where the neutrino masses are such that m_1\\alt m_2\\ll m_3, taking into account several phenomenological constraints on neutrino mixing angles and masses. A solution of the solar neutrino problem for large values of the parameter \\delta m^2=m_2^2-m_1^2 which are not usually associated with a resonance is found. This is an essentially three-generation effect.

Science.gov (United States)

... table (ASCAMP) system and the Military Strategic and Tactical Relay (Milstar) program. 10 ... Single Channel Antijam Milstar Portable Terminal ...

International Nuclear Information System (INIS)

... mixing coupled channel theory differential cross sections excited states helium

Science.gov (United States)

... measurement. Power spectral density measurements are made by the dynamic signal analyzer for each channel. A cross power ...

UK PubMed Central (United Kingdom)

Inhibition of large conductance calcium-activated potassium (BK_Ca) channels mediates, in part, oxygen sensing by carotid body type I cells. However, BK_Ca channels remain active...Full Text Available

CERN Document Server

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

UK PubMed Central (United Kingdom)

Vacuolar ion channels in guard cells play important roles during stomatal movement and are regulated by many factors including Ca²⁺, calmodulin, protein kinases, and phosphatases....Full Text Available

UK PubMed Central (United Kingdom)

We have purified and characterized two peptides, named KAaH1 and KAaH2 (AaH polypeptides 1 and 2 active on K⁺ channels, where AaH stands for Androctonus australis Hector),...Full Text Available

UK PubMed Central (United Kingdom)

Methylosulfonomonas methylovora M2 is an unusual gram-negative methylotrophic bacterium that can grow on methanesulfonic acid (MSA) as the sole source of carbon and energy. Oxidation...Full Text Available

UK PubMed Central (United Kingdom)

Treatment of poliovirus Type I with 10⁻³m 2-thiouracil (2-TU) resulted in the inactivation of greater than 90% of the virus infectivity and stabilization of approximately...Full Text Available

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

This paper evaluates the electric current terms from the longitudinal gradient of the longitudinal electric field in Bipolar Field-Effect-Transistors (BiFETs) with a pure base and two MOS gates operating in the unipolar (electron) current mode. These nMOS-BiFETs, known as nMOS-FinFETs, usually have electrically short channels compared with their intrinsic Debye length of about 25 #mu#m at room temperatures. These longitudinal electric current terms are important short-channel current components, which have been neglected in the computation of the long-channel electrical characteristics. This paper shows that the long-channel electrical characteristics are substantially modified by the longitudinal electrical current terms when the physical channel length is less than 100 nm.

British Library Electronic Table of Contents (United Kingdom)

The investigation of steam, water, and air flow characteristics in horizontal channel is a part of major investigations program at the Lithuanian Energy Institute. The objective of this program is to identify condensation effects on two-phase flow stability and to predict conditions when rapid condensation could be induced in two-phase condensable flow. This article presents investigation of steam-water and air multiphase flow in nearly horizontal rectangular channel. The experimental data for pressure drop and interfacial and wall shear stresses in the channel with uniform distribution of void fraction are presented in this paper. Overall channel dimensions are length = 1.2 m, width = 0.02 m, height = 0.1 m; however, the test section was about 0.84 m in length. Three different flow types ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Sudden infant death syndrome (SIDS) is always a devastating and unexpected occurrence. SIDS is the leading cause of death in the first 6 months after birth in the industrialized world. Since the discovery in 1998 of long QT syndrome as an underlying substrate for SIDS, around 10-20% of SIDS cases have been proposed as being caused by genetic variants in either ion channel or ion channel-associated proteins. Until now, 10 cardiac channelopathy susceptibility genes have been found to be implicated in the pathogenesis of SIDS. Four of the genes encode cardiac ion channel a-subunits, 3 genes encode ion channel b-subunits, and 3 genes encode other channel-interacting proteins. All 10 genes have been associated with primary electrical heart diseases. SIDS may hereby be the initial sympt...

International Nuclear Information System (INIS)

Crystallization points of aqueous solution of the systems M(ClO_4)_2-H_2O (M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+), depending on the salt concentration, were identified by visual-polythermal method. Relying on model notions on the structure of the electrolyte solutions, specific features of strontium perchlorate solubility polytherm and concentration dependence of the relative dynamic viscosity of the salt aqueous solutions are discussed

International Nuclear Information System (INIS)

Previous flow regime studies have been for horizontal, vertical, and inclined pipe flow. As such, only a few studies have been performed on bundle geometries. The present paper examines the flow regimes for a vertical hexagonal flow channel with and without a finned fuel bundle. This type of a 36 finned rod hexagonal fuel bundle in parallel hexagonal flow channels is used in a MAPLE (Multi- purpose Applied Physics Lattice Experimental) type nuclear reactor. An experiment apparatus was designed consisting of the flow channel, inlet plenum and an air-water separator. The inlet plenum is used to provide a uniform mixture of air and water before entering the hexagonal flow channel. A turbine flow meter is used to determine the water flow rate. The turbine flow meter is calibrated for a low flow range and limits the measurable flow to 50 l/min. Flow pattern observation is determined by a SONY video camera, ...

International Nuclear Information System (INIS)

TAPP-3 and 4 are the 540 MWe PHWRs having horizontal fuel channel. At normal 100% FP operation there is no boiling in the channel. However, when the power increases due to any transient, the boiling may start in the channel. The main application for critical heat flux (CHP) prediction is to set the operating power with a comfortable margin to avoid CHF occurrence. This margin of CHF can be expressed in terms of minimum critical heat flux ratio (MCHFR), which is the ratio of CHF to local heat flux for the same pressure, mass flux and quality. The CHF depends on power, coolant flow rate as well as coolant condition in the channel. As the power increases the flow reduces in the channel and cooling is degraded. The thermal hydraulic code is developed for present analysis. The output of analysis are CHF prediction quality calculation at axial locations of the maximum rated ...

International Nuclear Information System (INIS)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and ...

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into channels filled with gas (stratified flow ...

CERN Document Server

We consider a noisy Slepian-Wolf problem where two correlated sources are separately encoded and transmitted over two independent binary memoryless symmetric channels. Each channel capacity is assumed to be characterized by a single parameter which is not known at the transmitter. The receiver has knowledge of both the source correlation and the channel parameters. We call a system universal if it retains near-capacity performance without channel knowledge at the transmitter. Kudekar et al. recently showed that terminated low-density parity-check (LDPC) convolutional codes (a.k.a. spatially-coupled LDPC ensembles) can have belief-propagation thresholds that approach their maximum a-posteriori thresholds. This was proven for binary erasure channels and shown empirically for binary memoryless symmetric channels. They also conjectured that the principle of spatial ...

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Crystallography and computer modeling have been used to exploit a previously unexplored channel in the glucocorticoid receptor (GR). Highly potent, nonsteroidal indazole amides showing excellent complementarity to the channel were designed with the assistance of the computational technique AlleGrow. The accuracy of the design process was demonstrated through crystallographic structural determination of the GR ligand-binding domain-agonist complex of the D-prolinamide derivative 11. The utility of the channel was further exemplified through the design of a potent phenylindazole in which structural motifs, seen to interact with the traditional GR ligand pocket, were abandoned and replaced by interactions within the new channel. Occupation of the channel was confirmed with a second GR crystal structure of this truncated D-alaninamide derivative 13. Compound 11 displays properties ...

Energy Technology Data Exchange (ETDEWEB)

To investigate the influence of equal channel angular pressing on the microstructure and texture of the magnesium alloy AZ31, electron backscattering diffraction and well as neutron diffraction experiments were carried out. Through these experiments it was possible to trace the microstructure and texture evolution with strain accumulated with the increasing number of equal channel angular pressing passes. It was further demonstrated by subsequent compression tests that the microstructural changes produced by equal channel angular pressing have a beneficial effect on both the compressive strength and ductility of AZ31. (orig.)

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

Purpose To study the activation and expression of vascular (aorta and small mesenteric arteries) potassium channels during septic shock with or without modulation of the NO pathway. Methods Septic shock was induced in rats by peritonitis. Selective inhibitors of vascular KATP (PNU-37883A) or BKCa [iberiotoxin (IbTX)] channels were used to demonstrate their involvement in vascular hyporeactivity. Vascular response to phenylephrine was measured on aorta and small mesenteric arteries mounted on a wire myograph. Vascular expression of potassium channels was studied by PCR and Western blot, in the presence or absence of 1400W, an inducible NO synthase (iNOS) inhibitor. Aortic activation of the transcriptional factor nuclear factor-kappaB (NF-?B) was assessed by electrophoretic mobility shift as...

UK PubMed Central (United Kingdom)

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

It has been considered that dry-out occurs easily in boiling heat transfer for a small channel, a mini- or microchannel, because the channel was easily filled with coalescing vapor bubbles. In the present study, the experiments of subcooled flow boiling of water were performed under atmospheric conditions for a horizontal rectangular channel for which the size is 1 mm height and 1 mm width, with a flat heating surface of 10 mm length and 1 mm width placed on the bottom of the channel. The heating surface has a top of copper heating block and is heated by ceramic heaters. In the high heat flux region of nucleate boiling, about 70-80% of the heating surface was covered with a large coalescing bubble and the boiling reached critical heat flux as observed by high-speed video. In the beginning ...

International Nuclear Information System (INIS)

For the determination of the thermal-hydraulic performances of rough surfaces, the method of evaluation is particularly important. In order to increase confidence in the results, a new evaluation procedure was introduced. This procedure is based on the transformation of simple channel experimental results to equal boundary conditions, and on the suitable application and confirmation of these transformed values in more complicated flow channel geometries. Existing methods, applied to the results obtained in an annular channel, do not fulfil all the transformation requirements. Thus a new, more complete transformation method, which uses the turbulent eddy diffusivity model, was developed. To check the quality of this transformation, within the scope of the new evaluation procedure, the results of experimental investigation in annular channels and in a bundle of hexagonal geometry were used together with ...

Energy Technology Data Exchange (ETDEWEB)

This report describes all time and frequency analysis parameters measured with the new Nuclear Weapons Identification System (NWIS) processor with three input channels: (1) the {sup 252}Cf source ionization chamber; (2) a detection channel; and (3) a second detection channel for active measurements. An intuitive and physical description of the various functions is given as well as a brief mathematical description and a brief description of how the data are acquired. If the full five channel capability is used, the number of functions increases in number but not in type. The parameters provided by this new NWIS processor can be divided into two general classes: time analysis signatures including multiplicities and frequency analysis signatures. Data from measurements with an 18.75 kg highly enriched uranium (93.2 wt%, {sup 235}U) metal casting for storage are presented to illustrate the various time and ...

Science.gov (United States)

A method for calculating flow through an airfoil cascade drawn on a surface of revolution is discussed. The three-dimensional flow was assumed to be represented by part-channels of varying width. The basic equations are the equation of continuity and the ...

Science.gov (United States)

... JTIDS) LPC-10 voice channel has been an important facet of a larger ongoing in-house research task on Digital Audio Technology for Aircraft ...

Science.gov (United States)

... thus can function as switches -6 ... Akkari, "Optical Channel Waveguide Switch and Coupler ... Wide-Band Guided Wave Acousto-Optic Bragg Diffraction ...

Energy Technology Data Exchange (ETDEWEB)

Experiments on heat transfer augmentation in a rectangular cross-section water channel are reported. The channel geometry is designed to excite normally damped Tollmein-Schlichting modes in order to enhance mixing. In this experiment, a hydrodynamically fully developed flow encounters a test section where one channel boundary is a series of periodic, saw-tooth, transverse grooves. Free shear layers span the groove openings, separating the main channel flow from the circulating vortices contained within each cavity. The periodicity length of the grooves is equal to one-half of the expected wavelength of the most unstable mode. The remaining channel walls are flat, and the channel has an aspect ratio of 10:1. Experiments are performed over the Reynolds number range of 300 to 15,000. Streakline flow visualization shows that the flow is steady at the entrance, but ...

Science.gov (United States)

of a stochastic network can be a. PERT-type network. After the terminal countdown, ...... pictorial representation of a single channel queueing system ...

British Library Electronic Table of Contents (United Kingdom)

Mixed convection heat transfer from longitudinal fins inside a horizontal channel has been investigated for a wide range of modified Rayleigh numbers and different fin heights and spacings. An experimental parametric study was made to investigate effects of fin spacing, fin height and magnitude of heat flux on mixed convection heat transfer from rectangular fin arrays heated from below in a horizontal channel. The optimum fin spacing to obtain maximum heat transfer has also been investigated. During the experiments constant heat flux boundary condition was realized and air was used as the working fluid. The velocity of fluid entering channel was kept nearly constant (0.15win0.16m/s) using a flow rate control valve so that Reynolds number was always about Re=1500. Experiments were conducted...

Science.gov (United States)

... time. The Paleozoic Era ended only 248 million years ago, the Mesozoic Era ended only 65 million years ago, and so on. ...

International Nuclear Information System (INIS)

During the last two decades, the demand for higher heat transfers in the heat exchangers has kept increasing. These high heat transfer rates can be obtained by using two-phase flows, or heat transfer augmented surfaces, or in some cases, both. Thus, the boiling flows and the associated two-phase flow instabilities have been studied by many investigators. Most of the work in boiling flows has been concentrated on single channel upflow systems or on parallel channel systems with plain heat transfer surfaces. The boiling flow instabilities in multi-channel systems should be covered to a greater extent, studying the effects of various parameters, such as inlet and outlet restriction, mass flow rates, the property variations, heat transfer coefficients, equal and unequal heat inputs on the stability. Also, the mathematical modeling needs to be developed for the parallel channel system to take into account ...

CERN Document Server

We consider a multiple-input multiple-output (MIMO) multiple access channel (MAC), where the channel between each transmitter and the receiver is modeled by the doubly-scattering channel model. Based on novel techniques from random matrix theory, we derive deterministic approximations of the mutual information, the signal-to-noise-plus-interference-ratio (SINR) at the output of the minimum-mean-square-error (MMSE) detector and the sum-rate with MMSE detection which are almost surely tight in the large system limit. Moreover, we derive the asymptotically optimal transmit covariance matrices. Our simulation results show that the asymptotic analysis provides very close approximations for realistic system dimensions.

International Nuclear Information System (INIS)

A two-phase flow regime map is developed experimentally and theoretically for a vertical hexagonal flow channel with and without a 36-finned rod hexagonal bundle. This type of flow channel is of interest to MAPLE-type nuclear research reactors. The flow regime maps are determined by visual observations and observation of waveforms shown by a capacitance-type void fraction meter. The experimental results show that the inclusion of the finned hexagonal bundle shifts the flow regime transition boundaries toward higher water flow rates. Existing flow regime maps based on pipe flow require slight modifications when applied to the hexagonal flow channel with and without a MAPLE-type finned hexagonal bundle. The proposed theoretical model agrees well with experimental results.

Science.gov (United States)

A comparison of benthic biodiversity in the North Sea, English Channel, and Celtic Seas. ICES J. Mar. Sci./J. Cons. int. Explor. Mer 56: 228-246. ...

CERN Document Server

We study the impact of very light sterile neutrinos (Delta m^2_new around 1 to 10 times 10^(-2) eV^2, sin^2 2theta_new<10^(-1)) on upcoming theta_13-driven reactor antineutrino experiments like Double-CHOOZ and Daya Bay. Oscillations driven by these vales of Delta m^2_new affect data in the near and far detectors differently and hence potentially modify the capability of these experimental setups to constrain and measure sin^2 2theta_13. We find that the hypothesis theta_new different from zero negatively impacts one's ability to either place an upper bound on sin^2 2theta_13 in the advent of no oscillation signal or measure sin^2 2theta_13 if a theta_13-driven signal is observed. The impact of sterile neutrino effects, however, depends significantly on one's ability to measure the recoil positron energy spectrum. If sin^2 2theta_new is larger than 10^(-2), upcoming theta_13-driven reactor ...

British Library Electronic Table of Contents (United Kingdom)

Summary The purpose of this study was to evaluate the efficacy of postoperative adjuvant chemotherapy with FOLFOX regimen on the outcome after LT for HCC patients who did not meet the Milan criteria. Ninety-five consecutive HCC patients with liver cirrhosis undergoing LT were enrolled. Fifty-eight who did not meet the Milan criteria were randomized to open-label treatment with or without adjuvant chemotherapy after LT (n?=?29/group). The FOLFOX chemotherapy protocol comprised 3-week cycles of oxaliplatin 100?mg/m2 on day 1, leucovorin (calcium folinate, CF) 200?mg/m2 on day 1 followed by 3-day, and 5-fluorouracil (5-FU) 2000?mg/m2 as a 48-h continuous infusion, for up to six courses in the 1st year after transplantation. Median survival was extended by 4.57?months by combination chemothera...

International Nuclear Information System (INIS)

Sealants for radon-resistant foundation construction must seal the gap between concrete sections. Modern sealants have such low permeability that seal performance depends only on the permeability of the material that contacts the sealant. The surface permeability of concrete walls and floors was measured by a specially designed permeameter, which measures the airflow induced by a pressure difference across a temporary test seal applied to the surface. The permeability of bulk concrete is about 10"-"1"5 m"2. Areas free of surface defects had surface permeability ranging from 10"-"1"4 to 10"-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2, too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Radon-resistant seals require either extended ...

International Nuclear Information System (INIS)

Full text of publication follows: The heat transfer and flow in narrow channels has lots of advantages such as compact structure, high efficiency, design flexibility and so on. So it is widely used in the fields such as the new reactor core plate elements, the once-through stream generator, compact heat exchangers as well as electronic components. In recent years, more strong attentions have been attracted to the thermal-hydraulic characteristics and mechanism of the two-phase flow in narrow channels. As the flow regime characteristics of two-phase flow is fundamental one of them, the research on the two-phase flow regimes and the regime transitions in horizontal rectangular narrow heated channels can provide theoretical foundation and engineering directions to the whole research on the thermal-hydraulic characteristics and mechanism of the two-phase flow in narrow channels. The characteristics of ...

Energy Technology Data Exchange (ETDEWEB)

This paper investigates steels 12Kh18N10T, 10Kh17N13M2T, 08Kh22N6T, and 08Kh21N6M2T. In corrosion of stainless steels in sulfuric acid solutions, dissolved sulfur dioxide acts as a cathodic depolarizer, capable of being reduced to elemental sulfur or forming sulfides with the metal. Depending on the conditions, this is associated with some increase in potential and greater or lesser increase in corrosion or facilitation of passivation of active steel. After passivation the influence of SO/sub 2/ is negligible. The results of this investigation were used as initial data for developing systems of anodic protection for shell-and-tube heat exchangers for sulfuric acid.

British Library Electronic Table of Contents (United Kingdom)

Machine-to-machine (M2M) communications is a new and rapidly developing technology for large-scale networking of devices without dependence on human interaction. Energy efficiency is one of the important design objectives for machine-to-machine network architectures that often contain multi-hop wireless subnetworks. Constructing energy-efficient routes for sending data through such networks is important not only for the longevity of the nodes which typically depend on battery energy, but also for achieving an environmentally friendly system design overall, which will be imperative as M2M networks scale in number of nodes as projected. The objective of this survey is to provide a comprehensive look into shortest-path based energy-efficient routing alternatives to provide a reference for sys...

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the corrosion and anodic behavior of steels 12Kh18N10T, 08Kh21N6M2T, and 06KhN28MDT, nickel, and molybdenum in 10-40% naturally aerated solutions of H/sub 2/TiF/sub 6/ at 20 and 50 degrees C. The authors found that in solutions of fluotitanic acid, as also in tetrafluoroboric and hydrofluoric acids, the most stable alloys are chromium-nickel-molybdenum alloy of type 06KhN28MDT and (for acid concentrations above 20%) copper-nickel-alloys of the monel metal type. Steels 12Kh18N10T and 08Kh21N6M2T can be used in acid concentrations of less than 10% and temperatures up to 20 degrees C with anodic protection.

British Library Electronic Table of Contents (United Kingdom)

The association between invasive and native species varies across spatial scales and is affected by phylogenetic relatedness, but these issues have rarely been addressed in aquatic ecosystems. In this study, we used a non-native, highly invasive species of Poaceae (tropical signalgrass) to test the hypotheses that (i) tropical signalgrass success correlates negatively with success of most native species of macrophytes at fine spatial scales, but its success correlates positively or at random with natives at coarse spatial scales, and that (ii) tropical signalgrass is less associated with native species belonging to the family Poaceae than with species belonging to other families (Darwin?s naturalization hypothesis). We used a dataset obtained at fine (0.25?m2) and coarse (ca. 1,000?m2) sca...

Energy Technology Data Exchange (ETDEWEB)

Short communication.

Science.gov (United States)

... structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria. BMC Evolutionary Biology 8: ... ...

Science.gov (United States)

Aluminum electrolytic capacitors, with 1043 failures, are a good example. Also, categorization by size and voltage reveals such frequencies of occurrence as ...

KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

Spider venoms provide a highly valuable source of peptide toxins that act on a wide diversity of membrane-bound receptors and ion channels. In this work, we report isolation, biochemical analysis, and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow patterns and frictional pressure gradients in flow in small, rectangular channels are being studies as part of a larger research program addressing phase-change heat transfer of pure refrigerants and refrigerant mixtures in plate-fin heat exchangers. Small rectangular flow channels were selected as representative of plain fin geometries. The particular channel reported herein has dimensions of 19.05 {times} 3.18 mm. Adiabatic flows of air/water mixtures, with the flow channel horizontal and the channel exit at near-atmospheric conditions, were utilized in the experiments. Analysis and interpretation of the pressure data relative to observed flow pattern transitions led to an objective method for determining the plug/bubble-to-slug flow transition. This method, together with visual observations, supplemented with photographic data, was used to develop a flow pattern ...

British Library Electronic Table of Contents (United Kingdom)

The steady-state advective flow in a long horizontal rectangular channel with rigid adiabatic boundaries in the presence of a uniform longitudinal pressure gradient is investigated. The stability of this flow with respect to perturbations of various types is studied. The dependence of the critical Rayleigh number on the Prandtl number is found for various aspect ratios.

Science.gov (United States)

Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.

UK PubMed Central (United Kingdom)

We have shown previously that raising extracellular Ca²+ inhibited the apical 70-pS K channel in the thick ascending limb (TAL; Wang, W.H., M. Lu, and S.C. Hebert. 1996. Am....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

The interaction between gravity convection and Marangoni convection in a horizontal rectangular channel filled with a liquid containing a surfactant and a drop of another liquid is numerically investigated. For large Schmidt numbers the occurring oscillatory regime of solutal convection is analyzed. In the model with a surface phase the effect of the adsorption and desorption processes on the convective flow structure is determined. The corresponding initial and boundary value problem is solved using a difference method.

Energy Technology Data Exchange (ETDEWEB)

An attempt was made to minimize the channeling tail by implantation along a random equivalent direction following a careful alignment of the target. In order to analytically determine the random equivalent directions, critical angles for channeling were mapped on a stereogram. Boron ions with energies of 17 and 45 keV are implanted along specified directions determined from the map. The depth distribution of the dopant is profiled by SIMS and the effects of water orientation upon the channeling tail are noted. Industrial common use of a 7/sup 0/ tilt is not optimum. However, implantation with the wafer tilted at 5.5 +/- 0.5/sup 0/ from the surface normal and rotated at 7.0 +/- 0.5/sup 0/ from a (100) plane shows the least channel-tail compared to implantation along other directions. Rapid thermal annealing (RTA) is a promising annealing method for shallow junction formation. Transient enhanced diffusion ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

In CANDU reactors, the Regional Overpower Protection Trip (ROPT) system protects the reactor against overpowers in the reactor fuel, whether due to localized peaking within the core or a general increase in core power levels. Due to Primary Heat-Transport System (PHTS) aging the ROP trip setpoint is decreasing over time. Reductions in ROP trip setpoints are required to maintain the required trip-probability and ROP trip effectiveness, and results in a decrease of the ROP margin-to-trip during normal operation. In addition, full power operation can be threatened. In this point, to recover ROPT margin, channel power needs to be redistributed. ROPT setpoint is very conservative in normal operation because distortion of regional overpower is over 1.2 times as nominal power in slow loss of regulation (SLOR). Channel power ratio (CPR) is enough low except the limiting channel of which worst case of design basis flux shape. If the ...

Energy Technology Data Exchange (ETDEWEB)

Some diagnostics at the National Ignition Facility (NIF), including the Gamma Reaction History (GRH) diagnostic, require multiple channels of data to achieve the required dynamic range. These channels need to be stitched together into a single time series, and they may have non-uniform and redundant time samples. We chose to apply the popular cubic smoothing spline technique to our stitching problem because we needed a general non-parametric method. We adapted one of the algorithms in the literature, by Hutchinson and deHoog, to our needs. The modified algorithm and the resulting code perform a cubic smoothing spline fit to multiple data channels with redundant time samples and missing data points. The data channels can have different, time-varying, zero-mean white noise characteristics. The method we employ automatically determines an optimal smoothing level by minimizing the Generalized Cross ...

Science.gov (United States)

Oct 20, 2002 ... ASNOWsfc_sfc_forecastTimeUnit 1 ASNOWsfc_sfc_gridSize 0 ASNOWsfc_sfc_height 0 ASNOWsfc_sfc_level 1 ASNOWsfc_sfc_max 1.9312 kg/m^2 ...

International Nuclear Information System (INIS)

The structures of bromocopper(II) complexes in methanolic (M1, M2, M3, M4), ethanolic (E), and aqueous (H) solutions were determined by the analyses of the Cu K- and Br K-edge EXAFS spectra using a curve-fitting method. The molar concentrations of Cu and Br in these solutions prepared by CuBr_2 and LiBr are 0.996 and 1.992 (M1), 1.015 and 5.381 (M2), 0.493 and 4.525 (M3), 0.260 and 4.073 (M4), 1.031 and 4.313 (E), and 0.982 and 5.426 (H). In M1 solution the interatomic distances for the Cu-O_e_q, Br_e_q-Cu, and Br_e_q-O_e_q (_e_q = equatorial) were 2.00A, 2.35A, and 3.15A respectively, and the Br_e_q-Cu-O_e_q angle was estimated as about 92 deg. Therefore, trans-dibromo bis(methanol)copper(II) complex with a slightly distorted planar structure was proposed to be dominant complex species in M1 solution. The interatomic distances in M2, M3, M4 and E solutions were ...

International Nuclear Information System (INIS)

Frictional pressure drop and heat transfer performance in a very narrow rectangular channel having one-sided constant heat flux and repeated-ribs were studied experimentally for turbulent water flows. Their empirical correlations were derived for designing target cooling channels to remove high heat flux generated at target plates in a high-intensity proton accelerator system. The rib pitch-to-height ratios (p/k) were 10 and 20 while holding the rib height constant at 0.2 mm, the Reynolds number (Re) from 2,400 to 98,500 under different channel heights (H) of 1.2 mm and 3.2 mm, the rib height-to-channel equivalent diameter ratio (k/D_e) of 0.088 and 0.036, respectively. The results show that the rib-roughened surface augments heat transfer by about 2-2.5 times compared with the smooth surface at the expense of around 2.5 times higher frictional pressure drop under a range of Re=8,000-to-30,000 at ...

Science.gov (United States)

Turbulent flow in a 2D channel with repeated rectangular rib roughness was numerically simulated using a low Reynolds number form of the k-epsilon turbulence model. Friction factors and average Stanton numbers were calculated for various pitch to rib height ratios and bulk Reynolds numbers. Comparisons with experiment were generally adequate, with the predictions of friction superior to those for heat transfer. The effect of variable properties for channel flow was investigated, and the results showed a greater effect for friction than for heat transfer. Comparison with experiment yielded no clear conclusions. The turbulence model was also validated for a related problem, that of flow downstream of an abrupt pipe expansion.

CERN Document Server

In pp collisions at 1.25 GeV kinetic energy, the HADES collaboration aimed at investigating the di-electron production related to $\\Delta$ (1232) Dalitz decay ($\\Delta^+ \\to pe^+e^-$). In order to constrain the models predicting the cross section and the production mechanisms of $\\Delta$ resonance, the hadronic channels have been measured and studied in parallel to the leptonic channels. The analyses of $pp\\to np\\pi^+$ and $pp\\to pp\\pi^0$ channels and the comparison to simulations are presented in this contribution, in particular the angular distributions being sensitive to $\\Delta$ production and decay. The accurate acceptance corrections have been performed as well, which could be tested in all the phase space region thanks to the high statistic data. These analyses result in an overall agreement with the one-$\\pi$ exchange model and previous data.

International Nuclear Information System (INIS)

The influence of hydrogen ion implantation into the channel polysilicon of polysilicon thin film transistors on gate oxide conductivity has been investigated. Data for effective tunnelling barriers at the gate oxide/channel polysilicon interface are presented. A value of 1.2eV for samples with boron doped channel polysilicon is calculated. For hydrogenated boron doped samples tunnelling barriers higher than 2.1 eV are obtained. The tunnelling barriers for phosphorus doped samples are impurity concentration dependent and decrease with increasing phosphorus concentration in the range 3 x 10"1"7 to 3 x 10"1"9 cm"-"3. (Author).

Energy Technology Data Exchange (ETDEWEB)

Recently it was demonstrated that long-lived quantum coherence exists during excitation energy transport in photosynthesis. It is a valid question up to which length, time and mass scales quantum coherence may extend, how one may detect this coherence and what, if any, role it plays in the dynamics of the system. Here we suggest that the selectivity filter of ion channels may exhibit quantum coherence, which might be relevant for the process of ion selectivity and conduction. We show that quantum resonances could provide an alternative approach to ultrafast two-dimensional (2D) spectroscopy to probe these quantum coherences. We demonstrate that the emergence of resonances in the conduction of ion channels that are modulated periodically by time-dependent external electric fields can serve as signatures of quantum coherence in such a system. Assessments of experimental feasibility and specific paths towards the experimental realization of such ...

Science.gov (United States)

Mixed convection in a rectangular channel (width/height = 2) with bottom-heated and top-cooled sections is studied by laser Doppler anemometry in nitrogen at Ra = 22,200 and Re = 18.75, 36, and 54. At the lower Re values, symmetry breaking is observed in steady but spatially oscillating flows that prevail over a certain distance from the leading edge of the differentially heated section. Further downstream, unsteady flows are found even for Re = 18.75. Numerical models are used to investigate the effects of adiabatic, conducting (with a conductive-convective heat transfer coefficient), and perfectly conducting side walls; channel tilts and Prandtl number dependence. Good agreement between calculations and experiment is obtained for longitudinal convective roll velocities. The transverse velocities are found to be independent of Re.

International Nuclear Information System (INIS)

Mass transfer to a wall of a horizontal rectangular channel reactor was investigated by the limiting current technique for Reynolds numbers ranging from 200 to 32000. Overall mass transfer coefficients at various mass transfer surface angles were obtained while the reactor was operated under isothermal and non-isothermal conditions. Dimensionless correlations were developed for isothermal flows from 25 to 55"oC and for non-isothermal flows with applied temperature differences up to 30"oC. In the laminar flow range natural convection dominated, but under turbulent conditions combined natural and forced convection prevailed. Mass transfer was approximately doubled under optimum selection of channel surface rotation, temperature gradient and flow rate. (author)

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE Controlling vascular tone involves K+ efflux through endothelial cell small- and intermediate-conductance calcium-activated potassium channels (KCa2.3 and KCa3.1, respectively). We investigated the expression of these channels in astrocytes and the possibility that, by a similar mechanism, they might contribute to neurovascular coupling. EXPERIMENTAL APPROACH Transgenic mice expressing enhanced green fluorescent protein (eGFP) in astrocytes were used to assess KCa2.3 and KCa3.1 expression by immunohistochemistry and RT-PCR. KCa currents in eGFP-positive astrocytes were determined in situ using whole-cell patch clamp electrophysiology. The contribution of KCa3.1 to neurovascular coupling was investigated in pharmacological experiments using electrical field stimulatio...

British Library Electronic Table of Contents (United Kingdom)

Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for controlling gully erosion is the installation of drop pipes. This practice involves placing earthen dams across eroding gullies and embedding a metal standpipe within the dam to convey water from the field to stream level. Installation of this structure halts gully erosion and incidentally replaces eroding gullies with riparian habitats. Previous research evaluating gully erosion control structures have not considered the ecological impacts of these conservation practices on amphibian and repti...

International Nuclear Information System (INIS)

The loss of seal of the H9 channel in vacuum, freeing the entire cross section of the front part, leads to a fast leak that progresses rapidly. The effect of depressurizing the reflector can leads to shutdown of the shutdown rod pumps. The source changer associated with the channel fills completely before the valve closes. All of the leak water remains contained within the source changer containment. After the valves open, cooling of the fuel element is handled by natural convection, requiring a reversal of the flow between the plates. This changeover, which takes place at a relatively low pressure level, could lead to local boiling in the fuel element. Consequently, irreversible transformations cannot be excluded as possibilities for the fuel element and even for the control rod. Subsequently, the can is refilled with heavy water with establishment of the usual pressure levels.

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To form a licensing basis for a new methodology for a fuel channel safety analysis code for CANDU-6 nuclear reactor, a CATHENA model for a post-blowdown fuel channel analysis has been developed, and tested for a high temperature thermal-chemical experiment CS28-1 [Lei, Q.M., 1993. Post-test analysis of the 28-element high-temperature thermal-chemical experiment CS28-1. In: 4th International Conference on Simulation Methods in Nuclear Engineering, Montreal, PQ, 1993]. Pursuant to the objective of this investigation, the current study has focused on understanding the involved phenomena, their interrelations, and how to maintain a good accuracy of the temperature and H2 generation rate prediction without losing the important physics of the involved phenomena. The transient simulation results ...

International Nuclear Information System (INIS)

Using a realistic three-body model, angular distributions for the "1"6O(d,p)"1"7O(1/2"+) reaction, based on the channel coupling array (CCA) theory and various forms of the coupled reaction channel (CRC) method are compared. Despite the different forms and theoretical foundations of these methods, they yield similar angular distributions, within the bound state approximations used herein. The expected breaking of time reversal inveriance in the approximated CCA theory is quite small over most of the angular range. Of all the methods used, coupling effects in the forward directions are largest for the post form of the CRC, indicating that it is the least reliable of the CRC forms for fitting data. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

Various measurement tools that are used in chaos theory were applied to analyze two-phase pressure signals with the objective of identifying and interpreting flow pattern transitions for two-phase flows in a small, horizontal rectangular channel. These measurement tools included power spectral density function, autocorrelation function, pseudo-phase-plane trajectory, Lyapunov exponent,s and fractal dimensions. It was demonstrated that the randomlike pressure fluctuations characteristic of two-phase flow in small rectangular channels are chaotic, and governed by a high-order deterministic system. The correlation dimension is potentially a new approach for identifying certain two-phase flow patterns and transitions.

International Nuclear Information System (INIS)

A Real-Time Neutron Radiography (RTNR) system is developed to determine two-phase flow parameters for a vertical co-current two-phase flow channel with a hexagonal finned bundle. Image processing techniques are applied to visualize the two-phase flow, and procedures for measuring flow regime, cross-sectional averaged void fraction, time averaged void fraction, and void distribution for this complex geometry are discussed. The results show that the experimental flow regime map agrees well with an existing flow regime model for a hexagonal fined bundle. The hexagonal finned bundle is observed to significantly affect the void fraction, void migration, and void fluctuation along the axial flow channel.

International Nuclear Information System (INIS)

The pressurized Heavy Water Reactor (PHWR) consists of horizontal calandria vessel containing a large number of pressure tubes (fuel channels) connected to the reactor inlet and outlet headers by individual feeders. Coolant flow distribution among the pressure tubes play a vital role in extraction of thermal power. For these reactors one of the design objectives is to achieve uniform coolant outlet temperatures by providing coolant flows according to the channel power. This is achieved by the design process known as feeder sizing. This basically consists of accounting for the individual channel power and centre line geometry of individual feeder and iteratively adjusting the feeder hydraulic resistances within the design constraints such as limiting flow velocities, channel flows. Recently, the first unit of 540 MWe i.e Tarapur Atomic Power Project (unit 4) has been commissioned. This paper discusses ...

UK PubMed Central (United Kingdom)

Variability in motor performance decreases with practice but is never entirely eliminated, due in part to inherent motor noise. The present study develops a method that quantifies how performers...Full Text Available

UK PubMed Central (United Kingdom)

Quartz has a dissipation factor of approximately 10(-4), which is an order of magnitude less than that of the best glasses previously used to fabricate patch pipettes; it's dielectric constant of 3.8...Full Text Available

UK PubMed Central (United Kingdom)

Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand...Full Text Available

UK PubMed Central (United Kingdom)

Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated...Full Text Available

International Nuclear Information System (INIS)

A survey is given of the influence of surface deformations on heavy ion reactions. Emphasis is put on the effect of zeropoint fluctuations in the entrance channel and on the effect on grazing collisions in terms of an imaginary part of the scattering potential. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Attention was focused on the fission process in light nuclear systems. A model calculation based on the transition-state model of nuclear fission was applied to {sup 47}V fission as populated through multiple entrance channels and to fusion-fission cross sections for production of {sup 28}Al through three different entrance channels. Angular distributions are shown for different mass channels of the {sup 29}Si+{sup 27}Al reaction at E{sub lab} = 125 MeV. Pronounced structure is seen in the symmetric and near-symmetric fission channels from the {sup 24}Mg+{sup 24}Mg reaction; cross sections for binary fragment emission are shown for E{sub lab} = 90 MeV. A large Bragg-curve detector was used in this experiment. Ways to optimize detector response were studied; in addition, the Bragg detector was instrumented with an internal position-sensitive multiwire proportional counter.

International Nuclear Information System (INIS)

This paper documents some of the recent uses of robotics for inspection and maintenance activities in Ontario Hydro's nuclear power plants in areas other than fuel channels and steam generators. 7 figs.

International Nuclear Information System (INIS)

A theoretical scheme for quantum secure direct communication (QSDC) is proposed, where a three-qubit symmetric W state functions as a quantum channel. Two legitimate communicators can transmit their secret information by using quantum teleportation and local measurements.

UK PubMed Central (United Kingdom)

Previous studies in several different trigeminal nerve injury/inflammation models indicated that the hyperexcitability of primary afferent neurons contributes to the pain pathway underlying mechanical...Full Text Available

UK PubMed Central (United Kingdom)

We report the use of cysteine-substituted mutants in conjunction with in situ oxidation to determine the physical proximity of a pair of engineered cysteines in the pore region of the voltage-gated...Full Text Available

CERN Document Server

Calcium (Ca) plays an important role in regulating various cellular processes. In a variety of cell types, Ca signaling occurs within microdomains where channels deliver localized pulses of Ca which activate a nearby collection of Ca-sensitive receptors. The small number of channels involved ensures that the signaling process is stochastic. The aggregate response of several thousand of these microdomains yields a whole-cell response which dictates the cell behavior. Here, we study analytically the statistical properties of a population of these microdomains in response to a trigger signal. We apply these results to understand the relationship between Ca influx and Ca release in cardiac cells. In this context, we use a first passage time approach to show analytically how Ca release in the whole cell depends on the single channel kinetics of Ca channels and the properties of microdomains. Using these ...

UK PubMed Central (United Kingdom)

AbstractA mechanism of how polyanions influence the channel formed by Staphylococcus aureus α-hemolysin is described. We demonstrate that the probability of several...Full Text Available

Science.gov (United States)

average bulk water temper ature rise, OF bulk water temperature at elevation z, OF bulk water temperature in channels 0 and 1, O F film temperature, OF ...

UK PubMed Central (United Kingdom)

INTRODUCTION:Gynura procumbens has been shown to decrease blood pressure via inhibition of the angiotensin‐converting enzyme. However, other mechanisms that...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Mixed convection heat transfer from longitudinal fins inside a horizontal channel has been investigated in the natural convection dominated region for a wide range of Rayleigh numbers and different fin heights and spacings. An experimental parametric study was made to investigate effects of fin spacing, fin height and magnitude of heat flux on mixed convection heat transfer from rectangular fin arrays heated from below in a horizontal channel. The optimum fin spacing to obtain maximum heat transfer has also been investigated. During the experiments constant heat flux boundary condition was realized and air was used as the working fluid. The velocity of fluid entering channel was kept nearly constant (0.02win0.025m/s) using a flow rate control valve so that Reynolds number was always about ...

CERN Document Server

It is well known that for ergodic channel processes the Generalized Max-Weight Matching (GMWM) scheduling policy stabilizes the network for any supportable arrival rate vector within the network capacity region. This policy, however, often requires the solution of an NP-hard optimization problem. This has motivated many researchers to develop sub-optimal algorithms that approximate the GMWM policy in selecting schedule vectors. One implicit assumption commonly shared in this context is that during the algorithm runtime, the channel states remain effectively unchanged. This assumption may not hold as the time needed to select near-optimal schedule vectors usually increases quickly with the network size. In this paper, we incorporate channel variations and the time-efficiency of sub-optimal algorithms into the scheduler design, to dynamically tune the algorithm runtime considering the tradeoff between algorithm efficiency and ...

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE Human K2P3.1 (TASK1) channels represent potential targets for pharmacological management of atrial fibrillation. K2P channels control excitability by stabilizing membrane potential and by expediting repolarization. In the heart, inhibition of K2P currents by class III antiarrhythmic drugs results in action potential prolongation and suppression of electrical automaticity. Carvedilol exerts antiarrhythmic activity and suppresses atrial fibrillation following cardiac surgery or cardioversion. The objective of this study was to investigate acute effects of carvedilol on human K2P3.1 (hK2P3.1) channels. EXPERIMENTAL APPROACH Two-electrode voltage clamp and whole-cell patch clamp electrophysiology was used to record hK2P3.1 currents from Xenopus oocytes, Chinese hamster o...

Energy Technology Data Exchange (ETDEWEB)

Compact heat exchangers have traditionally found wide application in the transportation industry, where they are used as evaporators and condensers in vapor compression cycles for air conditioning and refrigeration. Such heat exchangers possess numerous attractive features including high thermal effectiveness, small size, low weight, design flexibility, and pure counterflow, and they can accommodate multiple streams. Today, there is a widespread interest in expanding the range of application of compact heat exchangers to include phase-change heat transfer in the process industries, among others. An overall objective of this effort is to provide the basis for establishing design technology in this area. In the present study, small channel flow boiling heat transfer was extended to a rectangular channel (4.06 {times} 1.70 mm) using refrigerant 12 (R-12). As with the circular tube studies, the flow channel wall was ...

International Nuclear Information System (INIS)

Applying the theory of depositional system, the depositional facies and depositional systems of the Zhiluo Formation in Dongsheng area are systematically analysed, and the authors proposed that sediments of the Zhiluo Formation are of fluvial facies, and streams of the Zhiluo time experienced three evolution stages, namely: the early braided stream, the middle low sinuosity meandering stream and the late high sinuosity meandering stream. Based on features of paleoclimatic evolution, the Zhiluo Formation is divided into two lithological members. The lower lithological member consists of sediments of braided and low sinuosity meandering streams under humid-ward paleoclimatic conditions forming grey sedimentary formation. The upper member is composed of sediments of meandering streams under arid-hot paleoclimatic conditions representing complex-colored (mainly red) sedimentary formation. It is suggested that uranium mineralization in the study area is of channel ...

International Nuclear Information System (INIS)

Experimental investigations of the turbulence characteristics of the air flow above the wave surface of the film in the horizontal rectangular channel in the 5-20 m/s velosity range of the air rate change (Reynolds number for the air 120O0-48000, 100-1000 for the film) are carried out. It is shown that intensities of turbulent pulsations of the rate increase with the growth of liquid flow rate in the film especially in the region of large squall waves. The experimental results on the pulsations are presented in the dimensionless form by a universal dependence. Distributions of tangentials of turbulent stresses above the film are obtained, turbulent stresses are compared with friction losses at the phase interface.

CERN Document Server

An electroweak singlet scalar can couple to pairs of vector bosons through loop-induced dimension five operators. Compared to a Standard Model Higgs boson, the singlet decay widths in the diphotons and Z gamma channels are generically enhanced, while decays into massive final states like WW and ZZ are kinematically disfavored. The overall event rates into gamma gamma and Z gamma can exceed the Standard Model expectations by orders of magnitude. Such a singlet may appear as a resonant signal in the gamma gamma and Z gamma channels, even with a mass above the WW kinematic threshold.

International Nuclear Information System (INIS)

Special beam extraction channel is used at INR linac for isotope production. It starts from 160 MeV measuring and matching area of accelerator. This choice of beam extraction enables to direct to the target of isotope complex a proton beam of wide energy range up to 160 MeV. It is important for production of different types of nuclides. The measuring results of proton beam behavior in this region are presented. Required beam forming in 160 MeV measuring and matching area of accelerator and in beam extraction channel is discussed.

British Library Electronic Table of Contents (United Kingdom)

The present paper investigates the peristaltic transport of a couple stress fluid in an asymmetric channel with the effect of the induced magnetic field. The exact solutions of momentum and the magnetic field equations have been calculated under the assumptions of long wave length and low but finite Reynolds number. The expression for pressure rise has been computed numerically using mathematics software Mathematica. The graphical results have been presented to discuss the physical behavior of various physical parameters of interest. Finally, the trapping phenomena have been discussed for various physical parameters.

CERN Document Server

In source coding, either with or without side information at the decoder, the ultimate performance can be achieved by means of random binning. Structured binning into cosets of performing channel codes has been successfully employed in practical applications. In this letter it is formally shown that various convolutional- and turbo-syndrome decoding algorithms proposed in literature lead in fact to the same estimate. An equivalent implementation is also delineated by directly tackling syndrome decoding as a maximum a posteriori probability problem and solving it by means of iterative message-passing. This solution takes advantage of the exact same structures and algorithms used by the conventional channel decoder for the code according to which the syndrome is formed.

British Library Electronic Table of Contents (United Kingdom)

This paper deals with a mixed convection water flow in a horizontal rectangular duct, uniformly heated from one lateral vertical wall and thermally insulated elsewhere. The supplied heat flux induces a secondary flow, which structure is constituted of one longitudinal roll in the considered aspect ratio (??=?1.9), embedded into a return flow of possibly large stream wise extension (up to twenty channel heights). Such situation induces helicoidal trajectories for the fluid flow particles, which contributes to a heat transfer enhancement compared to purely forced convection flow.

CERN Document Server

Typical receiver processing, targeting always the best achievable bit error rate performance, can result in a waste of resources, especially, when the transmission conditions are such that the best performance is orders of magnitude better than the required. In this work, a processing framework is proposed which allows adjusting the processing requirements to the transmission conditions and the required bit error rate. It applies a-posteriori probability receivers operating over multiple-input multiple-output channels. It is demonstrated that significant complexity savings can be achieved both at the soft, sphere-decoder based detector and the channel decoder with only minor modifications.

International Nuclear Information System (INIS)

The application of medium energy ion scattering in combination with channelling and blocking to the study of the initial stages of palladium silicide formation is discussed. After a brief description of the experimental arrangement and method, the effects on the Rutherford backscattering spectra of depositing small quantities of palladium on clean Si(111) are reported. The uniformity and thermal stability of thin palladium silicide films grown at room temperature were measured. Finally, channelling and blocking results were used to carry out a structural analysis of thin epitaxial Pd_2Si layers. (Auth.).

Science.gov (United States)

The entrainment flow rate distribution, the gas velocity profile, and the concentration profile of droplets across the channel cross section in fully developed region of a horizontal rectangular channel of 150mm width and 50mm height were measured. The concentration profile of droplets was expressed by a simple equation based on a constant diffusion coefficient model. From this equation the effects of gravity and turbulent diffusion of droplets on the concentration profile were evaluated. The characteristic mean settling velocity of a group of droplets with various diameters was derived, and using this value the mean diffusion coefficient of the group of droplets was obtained

Energy Technology Data Exchange (ETDEWEB)

We investigate the interplay between crossed channel final state interactions and the constraints from two-particle unitarity for the reactions J/{psi}{yields}V{pi}{pi} and VK anti K, where V is either {omega} or {phi}. Using a model where the parameters are largely constrained by other sources, we find that, although small, crossed channel final state interaction can influence the amplitudes considerably, in special areas of phase space. These results cast doubt on the inapplicability of unitarity constraints on production amplitudes as recently claimed in the literature. (orig.)

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

The velocity distribution of electrons ejected close to the forward direction by 0.8-2 MeV/A ions traversing various solid targets, including a Au monocrystal, is measured in coincidence with emerging charge-selected ions. The velocity spectrum is observed to be independent of outgoing projectile velocity and charge state for polycrystalline targets. Measurements on the Au crystal under channeling conditions show dependences on final charge state, and are tentatively explained by assuming that the main contribution to the production yield comes from the non-channeled fraction of the ions. A simple model for the creation of the forward-ejected electrons is proposed, which accounts for most of the experimental findings.

Energy Technology Data Exchange (ETDEWEB)

Frictional pressure drop and heat transfer performance in a very narrow rectangular channel having one-sided constant heat flux and repeated-ribs for turbulent flow have been investigated experimentally, and their experimental correlations were obtained using the least square method. The rib pitch-to-height ratios(p/k) were 10 and 20 while holding the rib height constant at 0.2mm, the Reynolds number(Re) from 2,414 to 98,458 under different channel heights of 1.2mm, 2.97mm, and 3.24mm, the rib height-to-channel equivalent diameter(k/De) of 0.03, 0.04, and 0.09 respectively. The results show that the rib-roughened surface augments heat transfer 2-3 times higher than that of the smooth surface with the expense of 2.8-4 times higher frictional pressure drop under Re=5000-10{sup 5}, p/k=10, and H=1.2mm. Experimental results obtained by channel height, H=1.2mm shows a little bit higher heat transfer and ...

UK PubMed Central (United Kingdom)

BackgroundLate-onset sepsis in the premature infant is frequently revealed by severe, unusual and recurrent bradycardias. In view of the high morbidity and mortality...Full Text Available

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... herbaceous and low succulents (mostly Sesuvium portulacastrum, also Ipomea sp., Euphorbia sp.). Local informants revealed that historic colonies ... vegetation (Sesuvium portulacastrum, Suriana maritima, ...

Science.gov (United States)

Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...

UK PubMed Central (United Kingdom)

The rapidly emerging science of epigenetics and epigenomic medicine promises to reveal novel insights into the susceptibility to and the onset and progression of epileptic disorders. Epigenetic...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

We tested the hypothesis that overstorey of eucalypt forest dominated by tall, large diameter trees uses less water than regrowth stands in the high rainfall zone (>1100mmyear^-^1) of the northern jarrah (Eucalyptus marginata) forest in southwestern Australia. We measured leaf area, cover, sapwood area and sapwood density at three paired old and regrowth stands. We also measured sapflow velocity at one paired stand (Dwellingup) from June 2007 to October 2008. Old stands had more basal area but less foliage cover, less leaf area and slightly thinner sapwood. The ratio of sapwood area to basal area decreased markedly as tree size increased. Sapwood area of the regrowth forest stands (6.6+/-0.30m^2ha^-^1) was nearly double that of the old stands (3.4+/-0.17m^2ha^-^1), despite larger basal are...

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

International Nuclear Information System (INIS)

From the indoor radon problem arises a great challenge for the radiation protection of the population. The soil can be considered as the only source for high radon concentrations in buildings. The contribution of common building materials to high indoor concentrations with a range of 30 Bq/m"3 is negligible low. Therefore building materials for radon mitigation should be judged by their tightness against diffusive radon and not by their radon exhalation rate. Also isolation materials for mitigation should be radon tight. The radon diffusion coefficient describes the physical processes in relatively homogeneous samples. The diffusion coefficient D and the diffusion length R are very exactly determined by a self engineered measuring method. The range of D reaches from D = (0.0005 to 2.35) . 10"-"6 m"2/s for building materials and from D = (0.07 to < 10"-"6) . 10"-"6 m"2/s for isolation materials. ...

International Nuclear Information System (INIS)

We report the results of neutron-diffraction experiments on CeM_2Si_2 (M = Ag,Au,Pd,Rh) which were performed to explore the role of valence fluctuations and 4f hybridization in the magnetic ordering of cerium compounds. All four order antiferromagnetically, the first three exhibiting structures consisting of ferromagnetic layers with moments perpendicular to the layers, which are believed to be characteristic of 4f-4f interactions mediated through hybridization with conduction electrons. CePd_2Si_2 has an anomalously small moment (0.62#mu#/sub B/) in the ordered state. CeAg_2Si_2 exhibits an incommensurate longitudinal, static magnetization wave with moment and propagation direction along the a axis. The fourth compound, CeRh_2Si_2, has the highest known transition temperature (39 K) reported for cerium ordering; it exhibits another second-order transition at 27 K to a complex commensurate structure with modulated moments. The results are ...

British Library Electronic Table of Contents (United Kingdom)

Porous phosphate heterostructures (PPH), functionalized with different ratios of aminopropyl and mercaptopropyl groups, labelled as Nx=5,25,50-PPH and Sx=5,25,50-PPH, respectively, were tested as adsorbents for Ni(II) and Hg(II) found in industrial sewage from electroplating processes and button battery recycling. X-ray diffraction was used to study the structures. The specific surface area of the pristine material (PPH) was 620m^2g^-^1, whereas the specific surface areas of the modified mercaptopropyl (S5-PPH) and aminopropyl (N5-PPH) were 472 and 223m^2g^-^1, respectively. The adsorption data were fitted to a Langmuir isotherm model. The S5-PPH material was saturated by 120mmol Hg(II) per 100g of material, whereas for Ni(II) adsorption, N25-PPH material displayed the highest adsorption w...

CERN Document Server

We explore as clearly as possible the features of neutrino oscillation which are relevant for measurements of the CP violating Kobayashi-Maskawa phase delta and the sign of \\Delta m^2_{13}. We focus on the so called low-energy option and discuss principles for optimizing experimental parameters to measure these two quantities simultaneously. Toward the goal, we first formulate a method for obtaining a bird-eye view of the phenomenon of neutrino oscillation by introducing a new powerful tool called the ``CP trajectory diagram in bi-probability space''. It allows us to represent pictorially the three effects separately in a single diagram; effect from genuine CP violation due to the sin delta term, effect from the CP conserving cos delta term, and the fake CP violating effect due to earth matter. By using the CP trajectory diagram we observe that there is a two-fold ambiguity in the determination of delta which is related with the sign of Delta ...

DEFF Research Database (Denmark)

The tidal motion of the ocean water through the ambient magnetic field, generates secondary electric field. This motionally induced electric field can be detected in the sea or inland and has a potential for electrical soundings of the Earth. A first goal of the paper is to gain an understanding of the global distribution of the electric signal due to tidal ocean flow. We simulate the electric signals for two tidal constituents - lunar semidiurnal (M2) and diurnal (O1) tides. We assume a realistic Earth's conductivity model with a surface thin shell and 1-D mantle underneath. Simulations demonstrate that in some coastal regions the amplitudes of the electric field can reach 100 mV/km and 10 mV/km for M2 and O1 tides respectively. The changes of lithosphere resistance produce detectable changes in the tidal electric signals. We show that our predictions are in a good agreement with observations.