Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The impacted armor targets used in testing high density armor-piercing ammunition containing depleted uranium (DU) are subject to disposal as low-level radioactive waste. Because of the costs associated with disposal of the entire armor plate and the limited use of secured commercial sites in the future, the U.S. Army is seeking to identify and evaluate new technologies for decontaminating these armor plates. The objectives of this Phase I SBIR program are two-fold, namely: to develop a selective solvent that can decontaminate impacted armor targets containing DU for disposal or recycle, and to identify and characterize technologies that can remove depleted uranium from the solvent for solvent recycle and uranium recovery for easier hazardous-waste disposal.

Energy Technology Data Exchange (ETDEWEB)

The purpose of this project was to develop improved dynamic failure models for brittle materials (primarily ceramics). The approach to developing these failure models was to establish a database (ACERAM) in which fundamental material properties and processing information could be directly correlated with ballistic performance data. Under this contract, a comprehensive literature search was conducted, many contacts were established in the armor/anti-armor research and development community, and database development was undertaken. A more limited project was also undertaken to assess and compare the effects of material properties and penetration mechanisms on the ballistic performance of depleted uranium and tungsten alloy penetrators.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). In order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion on each shot. A wall candidate based on tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based on the vast experience with these materials in a nuclear ...

Energy Technology Data Exchange (ETDEWEB)

The method is used for repairing armored logging cables. It consists of preparing armor, subsequent connection of current-conducting strands and wires of the armor, and laying of the armor. Sections of connecting the wires of the armor of the lower and upper layers are scattered over the length of the fused section of the cable. In order to improve the fault strength of the cable, the junctions of connection of the armor wires are scattered among themselves at a distance determined by the Euler formula, and thermal tempering of the wire sections is carried out near these junctions, and then the fused section of the cable is reinforced.

Science.gov (United States)

... 041.034.0403 The Morphological Basis of the Armor-Like Folded Skin of the Greater Indian Rhinoceros ... hendo@um.u-tokyo.ac.jp ...

International Nuclear Information System (INIS)

Small scale mock-ups of the primary first wall, the baffle first wall, the shield block and a partial model for the edge of the primary first wall module were designed and fabricated incorporating most of the key design features of the ITER shielding blanket. All mock-ups featured the DSCu heat sink, the built-in SS coolant tubes within the heat sink and the SS shield block. CFC tiles was used as the protection armor for the baffle first wall mock-up. The small scale shield block mock-up, integrated with the first wall, was designed to have a poloidal curvature specified in the ITER design. Fabrication routes of mock-ups were decided based on the single step solid HIP of DSCu/DSCu, DSCu/SS and SS/SS reflecting the results of previous joining techniques development and testing. For attaching the CFC tiles onto DSCu heat sink in the fabrication of the baffle first ...

International Nuclear Information System (INIS)

In 2001, EFDA has assigned to ENEA a contract for the thermomechanical testing of six mock-ups of the ITER primary wall module. These small scale mock-ups, reproducing representative portions of the reference ITER primary wall panels, were fabricated during ITER EDA phase by solid hot isostatic pressing (HIPping) of an AISI 316L stainless steel back structure to a alumina dispersion strengthened (DS)-Cu alloy heat sink armored with beryllium tiles. The experimental program, carried-out at ENEA Brasimone CEF 1-2 thermal hydraulic facility, was focused on the thermal mechanical testing of these mock-ups aiming at verifying which tile geometry and manufacturing procedure assures the required reliability of the beryllium/DS-Cu alloy/SS joints at high incident heat flux (>0.8 MW/m"2) both at steady state and under thermal fatigue tests. The paper presents the progress in the experimental activity of the first test campaign ...

International Nuclear Information System (INIS)

This paper presents the present status of R and D activities on plasma facing components for fusion reactors, such as International Thermonuclear Experimental Reactor (ITER) and fusion demonstration reactor (DEMO). The plasma facing components (PFCs) as typified by divertor and first wall components are subjected to high heat flux and particle flux from fusion plasma. It is essential for these components to have sufficient heat removal capability and robust structure against those loadings. JAEA has been carried out to develop the ITER-PFCs which consist of copper alloys and armor materials with high thermal conductivity, such as carbon fiber composites, tungsten and beryllium. The demonstration of the thermomechanical performance of the ITER-PFCs by using mock-ups has successfully been made under close mutual cooperation between the participant countries of ITER. Currently, the activity on the development of the ITER-PFCs is in a qualification ...

Science.gov (United States)

... German Seventh Army. The Goodwood offensive by the British to the ... well. General P. Wood of tne Fourth Armored Division, rea ...

Energy Technology Data Exchange (ETDEWEB)

The ceramic composite armor has been lucubrated in the past 40 years. Ceramic can provide the same protection as metal, but it has lighter weight than metal. Ceramic has excellent ability of resisting kinetic energy projectile, because it can transfer energy to a large range by its fragmented cone and has higher ability of eroding the projectile than metal. But the researches indicated the full potential of the ceramic hard face has not been achieved because the significant interface between ceramic and metal has the unfavorable impedance effects and would induce tensile failure. FGM is a new type composite with continuous transition from ceramic to metal; it has no significant discrete materials interfaces between ceramic and metal. This paper deals with the impact response of Ceramic/FGM/Metal armor by numerical and theoretical methods. Firstly, the ability of TiB{sub 2}/FGM/Metal armor resisting KE projectile is analyzed ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

It is well known that composite armors, consisting of glass elements confined with metallic tampers, are extraordinarily effective against shaped charge attack. Early experiments showed that jets fired against glass targets appeared to be bombarded by tiny fragments that destroyed alignment and reduced residual jet penetration. This result was attributed to an elastic rebound effect in which the outward radial motion of the target around the jet periphery was supposed to be arrested by tensile hoop stresses which developed behind the divergent shock front. Glass fragments were then accelerated radially inward and these destabilized the jet. To sustain the large tensile hoop stresses required, the glass must not have been fractured by the initial shock, behind which the stress state is typically well above the Hugoniot elastic limit. Modeling the penetration of a jet into glass requires not only determining the spall strength, i.e., the tensile ...

Science.gov (United States)

... Abstract : Iraqi armored and mechanized divisions crossed the border of ... quick response, the first elements of the 82nd Airborne Division arrived in ...

Science.gov (United States)

... F ? (28.3)(108) in an isotherme.l deformation with stationary principal axes of strain rate, but the component might be as small as F2= (19-3)(100) ...

Science.gov (United States)

This study evaluated the heat strain induced by six configurations of a new modular body armor (MBA) design. Tests were conducted in two environments differing only by wind speed. The environments were 40 deg C (104 deg F), 20% rh, wind speeds 1.0 msec-1 ...

International Nuclear Information System (INIS)

The present work summarizes efforts on the simulation of natural convection cooling within the IFMIF target and test cell. The simulations have been performed with the STAR-CD code using the k-#omega# high-Reynolds number turbulence model. A dedicated thermohydraulic model has been devised including Lithium loop components. Nuclear heat production has been calculated by the Monte-Carlo code McDeLicious for different parts of the target and test cell walls and was used as input for the STAR-CD simulations. Helium atmospheres at several pressures from 0.1 to 10"-"5 MPa have been investigated. In order to limit the maximum temperature of the concrete walls to 80 deg. C it was necessary to add thermal insulation layers to the hot Lithium loop surfaces and a conceptual system of two cooling layers in different depths of the concrete walls.

Energy Technology Data Exchange (ETDEWEB)

This research aims to develop reliable, advanced system thermal-hydraulic computer code and to quantify the uncertainties of code to introduce the best estimate methodology of ECCS for LBLOCA. Although the one of best estimate code, RELAP5/MOD3.1 was introduced from USNRC, several deficiencies in its reflood model and some improvements have been made. The improvements consist of modification of reflood wall heat transfer package and adjusting the drop size in dispersed flow regime. The tome smoothing of wall vaporization and level tracking model are also added to eliminate the pressure spike and level oscillation. For the verification of improved model and quantification of associated uncertainty, the FLECHT-SEASET data were used and upper limit of uncertainty at 95% confidence level is evaluated. (Author) 30 refs., 49 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

Numerical solutions given by a vorticity-velocity method are presented for combined free and forced laminar convection in the thermal entrance region of a horizontal rectangular channel without the assumptions of large Prandtl number and small Grashof number. The channel wall is heated with a uniform wall heat flux. Typical developments of temperature profile, secondary flow, and axial velocity at various axial positions in the entrance region are presented. Local friction factor and Nusselt number variations are shown for Rayleigh numbers Ra = 10{sup 4}, 3 {times} 10{sup 4}, 6 {times} 10{sup 4}, and 10{sup 5} with the Prandtl number as a parameter. The solution for the limiting case of large Prandtl number and small Grashof number obtained from the present study confirms the data of existing literature. It is observed that the large Prandtl number assumption is valid for Pr = 10 when Ra {le} 3 {times} 10{sup 4} but for a ...

Energy Technology Data Exchange (ETDEWEB)

A general calculation method for the analysis of transmission capability of a long-distance single-core ac submarine cable system is presented. The method is based on modal transformation of voltages and currents in multiconductor cable systems. Using this method, numerical calculations on 500 kV submarine cable systems have been performed with particular reference to the effect of the distance between bonds connecting metallic sheath, outer conductor and armor on the transmission capacity of the system. It was clarified that the transmission capacity of the system increased with decreasing bond intervals. Examination of the current distributions between various conductors along the length showed that this increase of transmission capacity was mainly due to the dispersion of the charging current into the metallic sheath, outer conductor and armoring at the bonding points. Analytical results for the transmission capacities of long-distance 500 ...

Energy Technology Data Exchange (ETDEWEB)

The utilization of electrically heated rods for the simulation of nuclear fuel pins represents a generally adopted method by the nuclear industry to study thermalhydraulic problems. Usually its is necessary to determine the time variation of the electric linear power to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be observed in the nuclear fuel pin. The present work analyzes the limits of the usually adopted simulation methods and shows a manner to obtain the required electrical linear power that reduces oscillations and yields accurate results for the thermal conditions of the rod surface wall. (author). 5 refs, 5 figs, 1 tab.

International Nuclear Information System (INIS)

The new Code Case to substitute the allowable crack angle for a circumferential surface crack in 'Rules on Fitness-for-Service (FFS)' published from The Japan Society of Mechanical Engineers (JSME). Until now, the angle of a circumferential surface crack was limited below 60deg. This is the limitation with consideration to the stability of the crack if the deep crack penetrates wall of the pipe. Therefore, a long crack (such like an SCC) was obliged to repair or replace even if it was shallow enough. Weld Overlay (WOL) repair in which strength of the original piping is ignored is also inapplicable for the same reason. In order to solve this irrationality, the new Code Case applying to the crack stability assessment when the crack angle exceeds 60deg was established, and allowable crack depth according to the crack angle were defined in it. (author)

Science.gov (United States)

A new magnetic electron microscope, UEMB-100, was designed with an increased electron-optical parameter. The electron-optical system consists of an electron canon (the high voltage is supplied by armored lead) and condensed, objective, intermediate, and projection lenses. In contrast to other native apparatuses, the microscope has a high resolving property (up to 20A) snnd great universality. (tr-auth)

Energy Technology Data Exchange (ETDEWEB)

Two mechanical design requirements are defined for the SSC Collider beam tube. First, the vacuum requirement (luminosity lifetime = 150 hrs). It requires the design of a pressure boundary within the cold mass vessel to provide a vacuum tunnel for the proton beam and to minimize the synchrotron radiation gas desorbtion with a suitable material. The Collider beam tube design is under an intensive activity to search for a material that will meet the luminosity requirement without a distributed pump or liner. Second is the tube wall`s resistivity requirement ({sigma}*t = 2E5 {Omega}{sup {minus}1}). For a 4.2 K beam tube the Cu thickness is 100 {mu}m (RRR=30,6.7 T, {sigma}=2E9{Omega}{sup {minus}1}m{sup {minus}1}). The copper yield strength is relatively low in comparison to steel and, therefore, the design of the steel layer is governed by the copper layer yield stress limit. A beam tube subjected to eddy current load in a quenching dipole requires ...

Energy Technology Data Exchange (ETDEWEB)

An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, ...

Energy Technology Data Exchange (ETDEWEB)

This report documents the concluding efforts at the Engineering Sciences Laboratory of TRW on two specific areas of current research activity within the more general context of proposed lean-burn operation of Otto-cycle-type automotive engines. These areas are: (1) achievement of knock-free performance, both under available fuels and current compression ratios and also under higher-octane fuels (e.g., alcohols) and higher-compression-ratio design (for greater thermal efficiency); and (2) identification of counterstrategies for two-wall (crevice-type) quenching of flame propagation, a phenomenon now widely acknowledged to be the major source of unburned-hydrocarbon emissions exhausted from homogeneous-charge cyclinders. There are certainly other highly active areas of research in Otto-cycle engines, such as turbocharging, ignition devices, and valve design, but the two above-cited topics were the topics of this project.

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is the measurement of two-phase flow parameters to support development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR). A single element finned Fuel Element Simulator was used with R134a Freon flow. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distributions were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the local void distribution ...

International Nuclear Information System (INIS)

The measurement of two-phase flow parameters and development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR) is discussed in this paper. A single element finned Fuel Element Simulator (FES) was used with R134a Freon as the working fluid. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distribution were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly limits any significant vibration and the local void ...

International Nuclear Information System (INIS)

The natural convection characteristics of gas in a vertical narrow annular gap which had its bottom opened to high temperature fluid and its upper shielding exposed to low temperature sealant have been evaluated from simulated fluid experiments using water and from calculations using the three-dimensional thermal hydraulic analysis computer code THERVIS-III. The following results were obtained: (1) The critical Rayleigh number which represented the limit of convection generation increased as the aspect ratios #epsilon#_1 (height/circumference) and #epsilon#_2 (height/gap distance) increased. (2) The flow pattern along the circumferential direction was seen to depend more strongly on the radiant heat from the side wall, rather than the aspect ratios #epsilon#_1 and #epsilon#_2. (3) The temperature difference along the circumferential direction in the annular gap obtained from the calculation code coincided with that obtained from experiments ...

British Library Electronic Table of Contents (United Kingdom)

As portable electronics become more advanced and alternative energy demands become more prevalent, the development of advanced energy storage technologies is becoming ever more critical in today's society. In order to develop higher power and energy density batteries, innovative electrode materials that provide increased storage capacity, greater rate capabilities, and good cyclability must be developed. Nanostructured materials are gaining increased attention because of their potential to mitigate current electrode limitations. Here we report on the use of vertically aligned multi-walled carbon nanotubes (VA-MWNTs) as the active electrode material in lithium-ion batteries. At low specific currents, these VA-MWNTs have shown high reversible specific capacities (up to 782mAhg^-^1 at 57mAg^-...

Energy Technology Data Exchange (ETDEWEB)

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{sup o}C and for non-isothermal flows with applied temperature differences up to 30{sup o}C. 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)

Energy Technology Data Exchange (ETDEWEB)

Thin films of sodium montmorillonite clay and cationic polyacrylamide were grown on a polyethylene terephthalate film using layer-by-layer assembly. After 30 clay-polymer layers are deposited, with a thickness of 571 nm, the resulting transparent film has an oxygen transmission rate (OTR) below the detection limit of commercial instrumentation (< 0.005 cc/m{sup 2}/day/atm). This low OTR, which is unprecedented for a clay-filled polymer composite, is believed to be due to a brick wall nanostructure comprised of completely exfoliated clay in polymeric mortar. With an optical transparency greater than 90% and potential for microwaveability, this thin composite is a good candidate for foil replacement in food packaging and may also be useful for flexible electronics packaging.

CERN Document Server

The nucleation and propagation of hydrofractures by injection of over pressured fluids in an elastic and isotropic medium are studied experimentally. Non-Newtonian fluids are injected inside a gelatine whose mechanical properties are assumed isotropic at the experimental strain rates. Linear elastic theory predicts that plastic deformation associated to breakage of gelatin bonds is limited to a small zone ahead of the tip of the propagating fracture and that propagation will be maintained while the fluid pressure exceeds the normal stress to the fracture walls (Ch\\'avez-\\'Alvarez,2008) (i.e., the minimum compressive stress), resulting in a single mode I fracture geometry. However, we observed the propagation of fractures type II and III as well as nucleation of secondary fractures, with oblique to perpendicular trajectories with respect to the initial fracture. In the Video (http://hdl.handle.net/1813/14122) experimental evidence shows that ...

CERN Document Server

Two-dimensional simulations of the coarsening process of the isotropic/smectic-A phase transition are presented using a high-order Landau-de Gennes type free energy model. Defect annihilation laws for smectic disclinations, elementary dislocations, and total dislocation content are determined. The computed evolution of the orientational correlation length and disclination density is found to be in agreement with previous experimental observations showing that disclination interactions dominate the coarsening process. The mechanism of smectic disclination movement, limited by the absorption and emission of elementary dislocations, is found to be facilitated by curvature walls connecting interacting disclinations. At intermediate times in the coarsening process, split-core dislocation formation and interactions displaying an effective disclination quadrupole configuration are observed. This work provides the framework for further understanding of ...

British Library Electronic Table of Contents (United Kingdom)

Concrete is the primary material for building envelopes in some parts of the world, and its ability to store heat as well as its dynamic temperature changes will not only affect the deterioration rate of the exterior wall but will also greatly influence the energy efficiency of interior air conditioning. There are many methods for measuring the inner temperature of concrete, but they often have limitations, such as indirect estimation, cable installation requirements, high cost, or heterogeneity of the sample structure. In order to measure the internal temperature of concrete, this study integrated a Radio Frequency Integrated Circuit (RFIC) with a temperature sensor chip and embedded the device in concrete structures. A Smart Temperature Information Material (STIM) was thus developed. Thi...

Science.gov (United States)

A personal account of Richard Berendzen's life as president of The American University (AU) in Washington, D.C. during the 1983-1984 academic year is presented in diary form. The account describes his interactions with faculty, students, administrators, and people outside the university to further the goals of the institution. In the year prior to the diary entries, enrollments at AU had dropped unexpectedly while tuition had not been raised to make up for the shortfall. There were empty beds of former students who faced economic pressures. A union protested AU's consequent firing of its custodians and its contracting with an independent custodial firm, which employed primarily blacks as custodians. The issue of racism surfaced when students and faculty supported demonstrators. Since AU has no wholly assured flow of applicants or donors, Berendzen recognized that to improve, or even to maintain, the relative position of AU, he had to become not only its pedagogical leader but also a ...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis is a method, which has many advantages for analysing various historic artefacts, as it is relatively cheap, sensitive and non-destructive, and it allows measurements in-situ. However, this analysis has also certain limitations especially concerning sensitivity to chemical elements only, irrespective of the compounds or chemical forms in which these elements have been bonded. In addition, light elements emitting very soft X-rays cannot be measured, and in order to detect a wide range of elements, it is necessary to carry out repeated measurements with different radiation sources. Despite these limitations, valuable information can be obtained about the composition of historic materials and data about the origin and age of these artefacts can be derived. Analyses of wall paintings, ancient metal sculptures or other objects of art provide the basis for historic considerations documented ...

Energy Technology Data Exchange (ETDEWEB)

This report describes the preliminary thermalhydraulic analysis of HTR-10 steady state full power initial core to provide a benchmark calculation of VHTGR(Very High-Temperature Gas-Cooled Reactors) safety analysis code of GAMMA(GAs Multicomponent Mixture Analysis). The input data of GAMMA code are produced for the models of fluid block, wall block, radiation heat transfer and each component material properties in HTR-10 reactor. The temperature and flow distributions of HTR-10 steady state 10 MW{sub th} full power initial core are calculated by GAMMA code with boundary conditions of total reactor inlet flow rate of 4.32 kg/s, inlet temperature of 250 .deg. C, inlet pressure of 3 MPa, outlet pressure of 2.992 MPa and the fixed temperature at RCCS water cooling tube of 50 .deg C. The calculation results are compared with the measured solid material temperatures at 22 fixed instrumentation positions in HTR-10. The wall temperature distribution in ...

Energy Technology Data Exchange (ETDEWEB)

A highly sensitive and stable tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy){sub 3} {sup 2+}) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy){sub 3} {sup 2+} immobilized in the ECL sensor by adsorption of Ru(bpy){sub 3} {sup 2+} onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-titania-Nafion showed improved ECL sensitivity for tripropylamine (TPA) compared to the ECL sensors based on both ...

Energy Technology Data Exchange (ETDEWEB)

Two mechanical design requirements are defined for the SSC Collider beam tube. First, the vacuum requirement (luminosity lifetime = 150 hrs). It requires the design of a pressure boundary within the cold mass vessel to provide a vacuum tunnel for the proton beam and to minimize the synchrotron radiation gas desorbtion with a suitable material. The Collider beam tube design is under an intensive activity to search for a material that will meet the luminosity requirement without a distributed pump or liner. Second is the tube wall's resistivity requirement ([sigma]*t = 2E5 [Omega][sup [minus]1]). For a 4.2 K beam tube the Cu thickness is 100 [mu]m (RRR=30,6.7 T, [sigma]=2E9[Omega][sup [minus]1]m[sup [minus]1]). The copper yield strength is relatively low in comparison to steel and, therefore, the design of the steel layer is governed by the copper layer yield stress limit. A beam tube subjected to eddy current load in a quenching dipole ...

CERN Document Server

We study the production of gravitational waves from cosmic domain walls created during phase transition in the early universe. We investigate the process of formation and evolution of domain walls by running three dimensional lattice simulations. If we introduce an approximate discrete symmetry, walls become metastable and finally disappear. We calculate the spectrum of gravitational waves produced by collapsing metastable domain walls. Extrapolating the numerical results, we find the signal of gravitational waves produced by domain walls whose energy scale is around 10^10-10^12GeV will be observable in the next generation gravitational wave interferometers.

UK PubMed Central (United Kingdom)

The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available

Science.gov (United States)

The commercial solid phase microextraction (SPME) fibers are not stable enough in organic solvent and tend to swell and strip off from the silica fiber in the high performance liquid chromatography (HPLC) mobile phase, and therefore the application of SPME coupled online with HPLC is limited. In this study, an SPME fiber coated with single walled carbon nanotubes (SWCNTs), prepared by means of electrophoretic deposition, was coupled on line to HPLC for the determination of four endocrine-disrupting compounds, i.e. bisphenol A (BPA), estrone (E(1)), 17?-ethynylestradiol (EE(2)) and octylphenol (OP), in aqueous samples. The results showed that the SWCNTs coating on the prepared fiber did not swell and strip off from the platinum fiber throughout the experiment, thus indicating a high resistance to the HPLC mobile phase, the mixture of water and acetonitrile. The SWCNTs fiber had similar (for OP) or higher (for BPA, EE(2) and E(1)) extraction ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study was to assess the effect of adenosine-triphosphate (ATP) on hemodynamics and left ventricular (LV) function, and to examine the value of ATP radionuclide-ventriculography (RNVG) for detecting coronary artery disease (CAD) in comparison with standard exercise RNVG. Thirty-eight consecutive patients with suspected CAD underwent ATP (0.18 mg/Kg/min) RNVG and symptom-limited exercise RNVG. Coronary angiography revealed 27 patients with CAD (Group S) and 11 without CAD (Group N). In group S, exercise induced an increase in LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV), and a decrease in LV ejection fraction (LVEF). In contrast, ATP infusion caused LVESV to decrease in both groups, improving LVEF. Only 14 of 39 segments whose wall motion was deteriorated by exercise showed worsening regional wall motion during ATP infusion. The sensitivity and specificity of ATP RNVG for detecting ...

KoreaScience (Korea)

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KoreaScience (Korea)

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Medline Plus

... presentation will be archived on the OR-Live website. 00:46:02 ANNOUNCER: This has been a ...

International Nuclear Information System (INIS)

Complex abdominal lesions include a variety of pathologies, such as septated, infected, and hemorrhagic cysts, abscesses, tumors, and fluid collections of different ethiology. These lesions present diagnostic difficulties with both Ultrasonography (US) and Computed Tomography (CT), since findings may not be present or, when present, are not specific. Keeping these limitations in mind, we evaluated 105 patients (111 abdominal lesions) with both US and CT in order to compare their adequacy in predicting the nature of the lesion. On the basis of US and CT results, complex abdominal lesions were divided in four classes: class I includes 43 cases in which both examinations gave the same contribution to the definition of the nature of the lesion, class II (14 lesions, mainly sperimentated cysts), in which US was superior to CT, class III includes 45 cases of hemorrhagic cysts, abscesses, fluid collections and, less frequently, cystic tumors; class IV includes 9 cases in ...

International Nuclear Information System (INIS)

Certain postulated faults during refuelling of AGRs may give rise to compacted fuel and graphite sleeve debris. This debris must be maintained below some safe limiting temperature. As part of a programme to assess the benefits of natural convection in cooling such debris in a region experiencing no forced cooling, a simple geometry incorporating typical debris has been studied both experimentally and by prediction. The experiment comprised an array of electrically heated fuel rods mounted co-axially in a closed cylindrical vessel and surrounded by fragments of graphite. The vessel was cooled on its cylindrical surface, the ends being insulated. Rods and vessel wall were thermocoupled. Tests covered a range of temperature and pressures in both CO_2 and N_2. Significant natural convection heat removal was demonstrated, particularly at high pressure. Predictions utilising the PHOENICS code agreed well with measured temperatures over a wide range ...

Energy Technology Data Exchange (ETDEWEB)

A mathematical model of a mineral melting cupola furnace for stone wool production has been developed for improving cupola operation. The 1-D, first-engineering-principles model includes mass and heat balances for the gas phase, five solid phases, and four liquid phases. The gas and solid/liquid phases flow countercurrently. Seven chemical reactions account for the conversions of coke, iron oxide, limestone, and gaseous species. The heterogeneous reactions of coke conversion are limited by both kinetics and mass transport. Heat transfer between phases is modeled including both convection and radiation. The model predicts gas concentrations; mass flow rates; and temperature profiles of the solid, melt, and gas in the cupola, as well as heat loss to the water-cooled walls. Inputs to the model include the coke, rock, and blast air properties, the blast air amount, and the coke percentage in the charge. The unknown model parameters are estimated on ...

Energy Technology Data Exchange (ETDEWEB)

Electron trapping in crossed electric and magnetic fields is an important mechanism by which electrical discharges can develop in low pressure gases. The authors report observations of discharges produced by this mechanism around a spherical anode in two space simulation chambers, namely the Space Plasma Interaction Experiment (SPIE) at the University of Maryland, and the NASA-Lewis B-2 chamber. They have identified two types of discharges in these experiments. In the B-2 chamber, the breakdown takes the form of a runaway dischage with spherical topology, limited only by the ability of the power supply to provide the current. In the SPIE chamber this type of discharge also occurs, in addition to a low current toroidal discharge which is observed at higher magnetic fields. They present measurements of both types of discharge and show how the trapping effect of the magnetic field together with secondary electron emission by high energy ion bombardment of the chamber ...

Energy Technology Data Exchange (ETDEWEB)

A novel composite film, comprising of hydrophobic ionic liquid (IL), multi-walled carbon nanotubes (MWNTs) and gold nanoparticles (GNP), was fabricated and characterized. The GNP was introduced through electrochemical deposition on IL-MWNT gel film coated glassy carbon electrodes (GCE). Experiments showed that both IL and MWNTs could facilitate the GNP deposition. With GNP the composite film exhibited smaller electron transfer resistance and higher sensitivity in sensing guanine (G) and adenine (A). Under the optimized experimental conditions, the anodic peak currents were linear to the analyte concentration in the ranges of 0.008-2.0 {mu}M. The detection limits were down to nanomole level after an accumulation of 150 s on open-circuit. In addition, on the composite film coated GCE, the anodic peaks of G and A were well separated, and their response sensitivities kept almost unchanged no matter whether they coexisted or not. This proposed ...

Energy Technology Data Exchange (ETDEWEB)

An impinging jet is a widely used technique for realizing high heat-transfer rates between a fluid and a surface. However, the area of enhanced heat transfer is limited to the neighborhood of the stagnation point. In this study, heat transfer is augmented remote from the stagnation point in an impinging plane jet system by a rod array located near the wall. Each square rod in the array was positioned normal to the flow direction and parallel to the flat plate surface. The distance between the nozzle and the flat plate (H) and the spacing between the rods and the flat plate surface (C) were changed to find the optimum values. The largest heat-transfer augmentation was obtained for C = 1 mm, H/B = 10, where the jet nozzle width is B. In this case, the heat-transfer coefficient averaged over an area 2B from the stagnation point is about 1.6 times greater compared to that without a rod array.

Energy Technology Data Exchange (ETDEWEB)

Radiological findings of chest and abdominal wall involvement in Hodgkin's disease are reported. This manifestation was diagnosed in one patient in the primary staging and in two patients during the course of the disease. Typical radiological findings are soft tissue masses in the chest and abdominal wall, in two cases with continous tumor growth of enlarged mediastinal lymphnodes into the anterior chest wall. The axial computed tomography is the best method to evaluate the extent of chest and abdominal wall involvement in Hodgkin's disease.

Science.gov (United States)

The purpose of this study was to evaluate the resin-dentin interfacial morphology and shear bond strength of several new and experimental dentin bonding systems classified as single-bottle/total etch, multi-step/total etch, and self-etching. Class 1 and 5 cavities were prepared from freshly extracted permanent molars and restored with composite resin. Each bonded sample was cross sectioned and one-half was completely demineralized and deproteinized, while the other half was polished along the cut surface to permit measurement of the thickness of resin-infiltrated dentin layer (RIDL) within intertubular dentin (iRIDL) and around the peritubular walls (pRIDL) of resin tags by SEM. Shear bond strength was measured for all the systems 2 minutes after photocuring. SEM showed iRIDL and resin tags of different morphology depending on material and dentin location. The iRIDL was thinner in superficial dentin and thicker in deep dentin. Peritubular RIDL (pRIDL) was thinner ...

International Nuclear Information System (INIS)

A review of tests on earthquake-resistant reinforced concrete structural walls is presented. Laboratory tests of isolated walls and construction joints are discussed. Where appropriate, design recommendations are given. The review indicates only few experimental data are available for short walls which are directly applicable to nuclear power plant design. In particular, tests of short rectangular walls subjected to load reversals are needed. Tests are also needed to determine the damping and frequency characteristics of cracked short walls. Analytical and experimental results should be correlated so that the hysteretic response observed in tests can be realistically related to the analytical response 'demand' of nuclear power plant structures. (Auth.).

UK PubMed Central (United Kingdom)

Walled-off pancreatic necrosis (WOPN), formerly known as pancreatic abscess is a late complication of acute pancreatitis. It can be lethal, even though it is rare. This critical review provides an overview...Full Text Available

UK PubMed Central (United Kingdom)

The fungal pathogen Candida albicans is one of the leading causative agents of death in immunocompromised individuals. It harbors an arsenal of cell wall anchored factors that are implicated...Full Text Available

UK PubMed Central (United Kingdom)

The objective of this study was to determine if inflammatory tolerance and enhancement of innate immune function could be induced by the gram-positive cell wall component peptidoglycan (PGN)....Full Text Available

UK PubMed Central (United Kingdom)

A technique is described for displaying distinct tissue layers of large blood vessel walls as well as measuring their mechanical strain. The technique is based on deuterium double-quantum-filtered (DQF)...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundClinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD)...Full Text Available

UK PubMed Central (United Kingdom)

Primary cell walls, free from cytoplasmic contamination were prepared from corn (Zea mays L.) roots and potato (Solanum tuberosum) tubers. After EDTA treatment, the...Full Text Available

UK PubMed Central (United Kingdom)

Purified cell walls were prepared from roots of Horse bean (Vicia faba L., var. minor) and Yellow Lupine (Lupinus luteus L.). Two methods were used:...Full Text Available

International Nuclear Information System (INIS)

The ion nitriding treatment is a process widely used in steel alloys to improve the material's properties; such as surface hardness, resistance to wear, fatigue life and resistance to corrosion. But geometric changes in the components can produce during the nitriding process different effects on the behavior of the plasma, such as local variations in the electric field, an empty cathode effect, etc. These in turn can affect among other factors the local temperature and therefore the kinetics of the process, generating variations in the compound layer thicknesses and zone of diffusion, and micro-hardness profile. These heterogeneities limit the effectiveness of the plasma nitriding process, where control and duplication of the surface modification are most important. This work aims to study the effect of the geometry of the pieces treated with ionic nitriding, especially the effect of the orifices. An understanding of the operating mechanisms is sought in order to ...

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

Energy Technology Data Exchange (ETDEWEB)

A quantitative description is proposed for the depletion-induced slip thickness and velocity profile of a polymer solution near the wall-fluid interface in simple shear flow. The inhomogeneous polymer density profile at a flat wall is inserted into the equations of motion for the flow of a polymer solution near the flat wall. The theory is in quantitative agreement with simulation results. (letter to the editor)

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is to simplify assembly and to reduce labor intensity. This is achieved by the fact that the assembly shaft is positioned in a hawser, while its wall which is turned towards the body of the installation is combined with the hawser wall, where a U shaped opening is made in the wall of the assembly shaft, along the edges of which there is a hermetically sealing device, while the bottom of the body of the offshore drilling rig is equipped with a rigid insert attached with the capability of adjoining it with the hermetically sealing device.

Energy Technology Data Exchange (ETDEWEB)

With the combination of source ventilation and ceiling cooling for air-conditioning of working and recreation rooms, a ventilation system is available which fulfills the highest demands regarding thermal comfort. In order to utilize the advantages of this ventilation system with regard to air quality and thermal comfort to an optimum, the influence of the radiation exchange between cooling ceiling and walls on the flow in the room is investigated experimentally. Energy transfer from the walls to the cooled ceiling may result in an insufficient temperature of the walls compared to ambient air and in an upward flow on the wall surfaces (downward flow of) driven by gravity, which influences the flow pattern in the case of source ventilation. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Following Hurricane Katrina, the study of cantilevered sheet pile I-wall with gap or partial gap has become one of the central elements of the ongoing investigation pertaining to the re-building of hurricane protection systems in New Orleans, LA. Historically, the US Army Corps of Engineers (USACE) had mostly relied upon the Method of Planes (MOP) analysis procedure for slope stability analysis of I-wall systems. However MOP is a simplified procedure which does not satisfy total equilibrium. Nevertheless, MOP is still considered by USACE as a popular analysis tool because of its simplicity and ease of use in slope stability analysis. This paper demonstrates the applicability and suitability of MOP as a viable analysis tool for the analysis of New Orleans I-wall founded on layered cohesive ...

Energy Technology Data Exchange (ETDEWEB)

From the results of the In-Service Inspection (ISI) measuring the wall thickness of outlet (hot-leg side) feeder pipes performed at two Canadian nuclear power plants, Point Lepreau and Gentilly-2 in 1995 and 1996, respectively, the wall thinning degradation of feeder pipes at the bend part was found to be much more severe than expected. It has been well known that such wall thinning of feeder pipes is caused by the flow accelerated corrosion (FAC) which is one of the mechanical-chemical degradation mechanisms affecting the integrity of piping systems. For the Wolsung unit 1, the wall thickness measurements have been performed during every overhaul period since 1996. The wall thinning rates at the bends of outlet feeder pipes were assessed to exceed the design value. However, for the Wolsung units 2, 3 and 4, the wall thinning rates of all the outlet feeder pipes ...

International Nuclear Information System (INIS)

Testing of barrier properties of insulating materials against radon is usually based on the measurement of the radon diffusion coefficient. Presented report summarizes results of radon diffusion coefficients measurements in more than 120 insulating materials obtained throughout Europe. All measurements were performed by the Czech Technical University, Faculty of Civil Engineering in cooperation with the Radiation Protection Institute. We have found out that great differences exist in diffusion properties, because the diffusion coefficients vary within eight orders from 10"-"1"5 m"2/s to 10"-"8 m"2/s. For each material category of different chemical composition statistical evaluation of results is presented. Possibilities of usage of the radon diffusion coefficient for the design of radon resisting membranes are discussed. Based on the experience from the Czech Republic the paper is trying to show that controlling applicability of membranes by setting of the upper ...

Energy Technology Data Exchange (ETDEWEB)

Parallel imaging and echo sharing techniques have markedly reduced the acquisition times for MRI of large volumes. Dynamic 2 and 3-dimensional data sets of the chest with high temporal resolution (up to 10 images/s with single slice and 2 volume/s) allow an analysis of respiratory motion of the lungs and tumors. Time-resolved 2D series in preselected planes can be used to observe respiratory motion during free breathing or after respiratory commands, e.g. to exclude chest wall invasion by a tumor or for diagnosing impairment of respiratory mechanics. Time-resolved 3D-series (4D-MRI) allow monitoring of the spatial displacement of the lungs and tumors as a whole volume. Present limitations such as an overestimation of tumor size and an underestimation of displacement due to a limited temporal resolution are expected to be overcome with further technical developments. However, 4D-MRI already appears to be the appropriate tool ...

Energy Technology Data Exchange (ETDEWEB)

Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand mainly due to very poor load factors in milder climates. Thermal mass can be utilized to reduce the peak-power demand, downsize the cooling systems, and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the shortcomings of alternative cooling sources, or to avoid high demand charges. The manufacturing of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, would permit the thermal storage to become part of the building structure. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity, and their discharge is almost isothermal. This allows the storage of high amounts of energy without significantly changing the temperature of the room envelope. As heat storage takes place ...

Energy Technology Data Exchange (ETDEWEB)

The impingement of a fluid jet onto a surface has broad applications across many industries. Within the UK nuclear industry, during the final stages of fuel reprocessing, impinging fluid jets are utilised to mobilise settled sludge material within storage tanks and ponds in preparation for transfer and ultimate immobilisation through vitrification. Despite the extensive applications of impinging jets within the nuclear and other industries, the study of two-phase, solid loaded, impinging jets is limited, and generally restricted to computational modelling. Surprisingly, very little fundamental understanding of the turbulence structure within such fluid flows through experimental investigation is found within the literature. The physical modelling of impinging jet systems could successfully serve to aid computer model validation, determine operating requirements, evaluate plant throughput requirements, optimise process operations and support design. Within this ...

Energy Technology Data Exchange (ETDEWEB)

A cryocondensation pump was designed for the baffle chamber of General Atomics DIII-D tokamak and will be installed in the fall of 1992. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long and located in the lower outer corner of the vacuum chamber of the machine. It consists of a 1 m{sup 2} liquid helium-cooled surface surrounded by a liquid nitrogen-cooled shield to limit the heat load on the helium-cooled surface. The liquid nitrogen-cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. A thermal enhancement coating was applied to the nitrogen shell to lower the maximum temperature of the shell. The coating is non-continuous to keep the toroidal electrical resistance high. The whole pump is supported off the water-cooled vacuum vessel wall. Supports for the ...

International Nuclear Information System (INIS)

Quantitative gated SPECT (QGS) was evaluated in 7 normal volunteers and 31 patients with cardiac diseases. Adequate cut off value of a prefilter was 0.45. In phantom, the left ventricular volume value was 93.9% of determined value by 180-degree projection in L type and 98.8% by 360-degree projection in opposed type. In normal volunteers, LVEF measured by QGS program related to value by first pass method. As for functional map, regional EF and wall motion decreased at the septum side, and wall thickening at base side of heart. Good correlation was recognized (p<0.0001) between blood flow image and functional map (regional EF and wall thickening). In 20 cases of acute myocardial infarction, lesion was detected conspicuously in regional EF and wall motion. The accuracy of coronary arterial stenosis improved in functional map (regional EF 92%, wall motion 92% and ...

International Nuclear Information System (INIS)

This paper summarises the main results obtained so far in the frame of the EU Home Team test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show good thermal fatigue performance and operation margin of the ITER primary first wall concept. (author)

International Nuclear Information System (INIS)

This paper presents the main achievements of the European Home Team (EU HT) test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show very good thermal fatigue performance and operation margin of the ITER primary first wall concept.

Science.gov (United States)

We present evidence for the creation of an exchange spring in an antiferromagnet due to exchange coupling to a ferromagnet. X-ray magnetic linear dichroism spectroscopy on single crystal Co/NiO(001) shows that a partial domain wall is wound up at the surface of the antiferromagnet when the adjacent ferromagnet is rotated by a magnetic field. We determine the interface exchange stiffness and the antiferromagnetic domain wall energy from the field dependence of the direction of the antiferromagnetic axis, the antiferromagnetic pendant to a ferromagnetic hysteresis loop. The existence of a planar antiferromagnetic domain wall, proven by our measurement, is a key assumption of most exchange bias models.

Energy Technology Data Exchange (ETDEWEB)

An aspiration cover is proposed for the site of loading a belt conveyer including a housing arranged above the belt conveyer in whose cover there is an aspiration sleeve and a discharge chute from the upper wall and a guide having a cushioning plate on the lower end. It is distinguished by the fact that in order to improve the effectiveness of removing dust by decreasing the volume of aspirated air, the cover between the aspiration sleeve and the upper wall of the loading chute is convex in the inside of the housing and has a smooth connection to the upper wall of the discharge chute turned towards the cushioning plate.

Science.gov (United States)

... Figure 3a. PETN Filled Tube Specimen Detonated by Exploding Bridgewire Specimen POLYETIILLENE END-CAP "1- 901am WALL IHICKNESS ...

Science.gov (United States)

screens of fine wire was placed between the gun barrel and the panel to determine whether the gun performance was repeatable. The transducers were placed ...

British Library Electronic Table of Contents (United Kingdom)

We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure Formula Not Shown , above which the circular shape of the cross-section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs. Cross-sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 ...

International Science & Technology Center (ISTC)

Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain

Science.gov (United States)

We set a symmetric boundary at x=200 and a conducting wall at z=150. The domain of 0200. 0150 is resolved by 60004500 grid cells. Harris sheet ...

CERN Document Server

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

Science.gov (United States)

Figure 23 presented detailed layout of the cooling system designed for the Mach 6 hypersonic- transport. The distribution system consisted of thin-wall ...

Science.gov (United States)

... roughness. Since T u'v' and q v'"F the heat transfer augmentation is the square root of the skin friction augmentation: - 1/2 (( St - ,Cf 0 ...

UK PubMed Central (United Kingdom)

We investigated nutrient limitations during hydrocarbon degradation in a sandy soil and found that fixed nitrogen was initially a limiting nutrient but that N limitation could sometimes be overcome...Full Text Available

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In this thesis, increased hemicellulose retention during kraft pulping has been studied. The work has been divided into three parts: i) Development of an accessible and reliable method for determination of carbohydrate composition of kraft pulps ii) Investigation of the composition and molecular mass distributions of the carbohydrates in kraft pulps with increased hemicellulose content iii) Investigation of the effect of increased hemicellulose content on the sheet properties of kraft pulps with increased hemicellulose content. A method for carbohydrate determination was developed. In this method, enzymes are used to hydrolyse the pulp into monosaccharides. A relatively mild acid hydrolysis is performed prior to detection on an HPLC with an RI-detector. The pulp is not derivatized and no pre-treatment (mechanical or chemical) is needed to determine the carbohydrate composition using the method developed here. Peak deconvolution software is used to improve the accuracy. Polysulphide and ...

Science.gov (United States)

The change in concentrations of elements due to transmutations resulting from neutron irradiation in the first wall of the ARIES-IV conceptual fusion energy device were determined as a function of neutron dose. SiC burns out at a rate of about 0.5% per effective full power year. The largest impurity concentration is that of He, but several other elements burn in at rates of hundreds of appm/efpy.

Energy Technology Data Exchange (ETDEWEB)

In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.

Science.gov (United States)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively.

Energy Technology Data Exchange (ETDEWEB)

Ti honeycombs with the side of 800 and 400 nm were fabricated by focused ion beam (FIB), though the surfaces of the bottom and wall of the Ti honeycombs were rough, as compared with the surfaces of the bottom and wall of the Si honeycomb. It is demonstrated that the nanoscale Ti components can be fabricated in a short time by FIB.

Energy Technology Data Exchange (ETDEWEB)

This work proposes an innovative blend of potassium carbonate (K{sub 2}CO{sub 3}) and piperazine (PZ) as a solvent for CO{sub 2} removal from combustion flue gas in an absorber/stripper. The equilibrium partial pressure and the rate of absorption of CO{sub 2} were measured in a wetted-wall column in 0.0 to 6.2 m K{sup +} and 0.6 to 3.6 m PZ at 25 to 110 C. The equilibrium speciation of the solution was determined by {sup 1}H NMR under similar conditions. A rigorous thermodynamic model, based on electrolyte non-random two-liquid (ENRTL) theory, was developed to represent equilibrium behavior. A rate model was developed to describe the absorption rate by integration of eddy diffusivity theory with complex kinetics. Both models were used to explain behavior in terms of equilibrium constants, activity coefficients, and rate constants. The addition of potassium to the amine increases the concentration of CO{sub 3}{sup 2-}/HCO{sub 3}{sup -} in solution. The buffer ...

International Nuclear Information System (INIS)

During the operation of a tokamak, the first wall elements suffer very high heat fluxes. Heat is removed by internal cooling by means of water, helium or fluid metal. The resulting inhomogeneous temperature field cause internal stresses which, due to the pulsed operation are of cyclic nature. Additional mechanical stresses in the first wall may be caused by disruptions or vertical plasma movements. During theses events high currents are induced in the metallic part of the first wall which by their interaction with the magnetic field of the tokamak lead to mechanical forces. These electromechanical stresses may lie beyond the yield stress of the structural material. From the interaction of thermal and mechanical forces, a complex stress state is achieved which under certain circumstances may lead to premature failure and/or to progressive plastic deformations (ratcheting). In order to study the boundary conditions for the ...

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: GDH impact on an adjacent GDH and its attached piping; and GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material ...

International Nuclear Information System (INIS)

Research highlights: #-># Morphological and chemical characterization at atomic scale of porous alumina layers anodised in ordered regimes. #-># Characterization based on the use of FEG-SEM, STEM-HAADF, STEM-EELS and STEM-X-EDS. #-># Nanoscale distribution of P-, C- and S-bearing species in the pore wall. - Abstract: Ordered porous alumina layers prepared by two-step anodising in phosphoric, oxalic and sulphuric acids have been characterized at sub-nanometer scale using electron microscopy techniques. FEG-SEM and STEM-HAADF images allowed estimating the pore size, cell wall and pore wall thicknesses of the layers. Nanoanalytical characterization has been performed by STEM-EELS and STEM-X-EDS. Detailed features of the spatial distribution of anions in the pore wall of the films have been obtained. Maximum concentration of P-species occurs, approximately, at the middle of the pore ...

Science.gov (United States)

The work reported in this paper is focused on an effective and efficient solution, namely Smart Isolation Mount for Army Guns (SIMAG), to the weapon stabilization and fire control issues facing US Army guns. SIMAG is composed of the optimum integration of two innovative technologies. Vibration Control by Confinement and smart senor/actuator/active control systems. The combined approach may also be applied to a gun barrel to reduce its undesired vibratory motions excited by external and internal disturbances, such as gun firing action. SIMAG reconfigures the distribution and propagation of excess vibration energy and confines vibrations to certain non-critical regions or modes within a structure. Concentrated passive, active, or smart damping elements or cancellation techniques may be applied to more effectively dissipate or cancel the trapped vibrations and to prevent build up in the assembly. As the active elements, an array of collocated, PZT-based sensor- actuator sets is ...

Science.gov (United States)

The use of ceramics as energy absorbents has been studied by many researchers and some improvements in the ballistic performance of ceramic tiles have been made by coating them with different classes of materials (e.g. E-glass/epoxy, carbon-fiber/epoxy, etc.). Using ceramics for energy absorbing applications leads to a significant weight reduction of the system. Therefore, any modification to the ceramic configuration in the system which leads to more energy absorption with the same or less areal density is significant. On the other hand, polyurea has been proved to be an excellent energy dissipating agent in many applications. Inspired by this, we are studying the effect of coating ceramics with polyurea and other materials, on the energy absorption and ballistic performance of the resulting ceramic-based composites. In this study, we investigate the effect of polyurea on ballistic efficiency of ceramic tiles. To this end, we have performed a set of penetration tests on ...

Energy Technology Data Exchange (ETDEWEB)

Based on the CFD-code FLUENT trademark, theoretical studies were conducted of the influences of incineration chamber geometry (direct, countercurrent and center flow) on the combustion process. The boundary conditions, e.g., the thermal input and the waste grate, were kept constant. Close attention was paid to the distribution of flow, spe-cies, and temperatures. In addition, the influence of a dis-placement body at the end of the combustion chamber was tested. The variation of different wall materials and the prediction of problem areas concerning corrosion, slagging, and contamination completed the studies. Close to the chamber walls, high CO-concentrations may indi-cate corrosion; particle flow may indicate where contami-nation, slagging or erosion could occur. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Heat transfer experiments were performed in the post-CHF two-phase flow regime in a vertical tube. The tube inside diameter was 7.75 mm, and the boiling fluid was R-113. The experiments were performed at steady state by means of liquid heating of the test tube. Wall superheats were maintained below 70 C for heat exchanger/steam generator application. The mass flux range of the data was 379-816 kg m{sup -2} s{sup -1}. The use of R-113 significantly extended the property range of the existing low wall-superheat data base. Experimental data are presented in tabular as well as graphical form, and the results were used with low wall-superheat data from other fluids to add generality to a predictive heat transfer correlation. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Combined gas and steam turbine processes based on direct coal firing show a high thermal efficiency. At RWTH Aachen, University of Technology, an experimental test furnace has been built to investigate the pressurized pulverized coal combustion (PPCC). The PPCC-facility has been constructed as a slag tap furnace. Particles hitting the walls at temperatures above the melting point cause slagging depositions and create a film flowing down the reactor walls. As a part of the PPCC-program different mathematical models have been developed and implemented into the CFD-code FLUENT to predict the behavior of slag films at the furnace walls. Numerical strategies and the mathematical models used are described in detail. 12 refs., 9 figs.

Energy Technology Data Exchange (ETDEWEB)

Lateral plume dispersion in deep river valleys during neutral and stable lapse rate conditions can be exceptionally high due to the intense horizontal turbulence generated by prominent variations in the width, orientation and surface roughness of the valley walls. Use of the standard Gaussian dispersion equation to represent this enhanced lateral plume spread in a narrow valley may be inappropriate since consideration should also be given to the restriction of the horizontal plume spread due to impingement against the valley walls. The basic concept employed in the modification of the Gaussian dispersion equation was to assume that multiple eddy reflections occur between the valley walls in a manner similar to the vertical eddy reflections between the ground plane and an inversion layer aloft. The expressions are developed, but no attempt has been made to validate them with actual measured field data. 4 references, 3 ...

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).

Energy Technology Data Exchange (ETDEWEB)

In order to develop the filler metal for Hastelloy alloy XR structure with thick wall, the weldability and high temperature strength properties of Hastelloy alloy XR weldment were investigated using the filler metals, which were alloy-designed on the basis of multiple regression analysis. The former was examined through the chemical analysis in the deposited metal, bend test, FISCO cracking test, optical microscopy and hardness measurement. The latter was investigated by means of tensile and creep test. It was found from these results that the crack susceptibility in the weldment was apparent to be lowered without degrading the high temperature strength properties. Therefore, it is concluded that these filler metals possess excellent performance as the filler metal for Hastelloy alloy XR structure with thick wall. (author).

International Nuclear Information System (INIS)

The distribution of the central benzodiazepine receptor specific ligand iodine-123 iomazenil was investigated in seven human adults from whole-body scans, blood samples and urine collected up to 24 h after injection. Using 12 source organs, the MIRD method was applied to calculate the absorbed radiation dose of the radioligand in various organs. The urinary bladder wall (0.15 mGy/MBq), lower large intestinal wall (0.071 mGy/MBq) testes (0.044 mGy/MBq) and upper large intestined wall (0.038 mGy/MBq) received the highest absorbed doses. The average effective dose equivalent of "1"2"3I-IBZM for adults was estimated to be 0.033 mSv/MBq. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.

Energy Technology Data Exchange (ETDEWEB)

The performance of a gas-fuelled diesel engine (dual fuel) is examined at light load and an effective threshold limit to the combustion of the gaseous fuel through bulk flame spread is identified. The relationship of such a limit to some of the key operating parameters is then discussed. A comparison between the measured values of the limit with those corresponding to the lower flammability limits of the gaseous fuel when evaluated under the prevailing cylinder conditions during pilot diesel fuel ignition showed similar trends. It is suggested that such a similarity may form a basis for estimating the lean operation limits for duel a fuel combustion in engines. A simple approach for estimating the limiting equivalence ratio for the apparent bulk flame spread limit is described for a methane-fuelled dual fuel engine. (Author)

Energy Technology Data Exchange (ETDEWEB)

The wavenumber-frequency spectral densities of turbulent wall pressure fluctuations are investigated over a rigid flat plate. Nonlinear Reynolds stress terms of the inhomogeneous Orr-Sommerfeld equation are regarded as a known forcing function. The forcing function is modeled after Bark{close_quote}s hydrodynamic bursting formulation. The inhomogeneous Orr-Sommerfeld equation is solved by the method of Eckhaus in terms of discrete homogeneous solutions. The method of Eckhaus is then extended and proved for the continuous Orr-Sommerfeld eigenfunctions. Turbulent wall pressure fluctuations in terms of wavenumber-frequency spectral densities are numerically computed and compared to the experimental results of Martin as well as to his transformation of Blake{close_quote}s data fitted to a modified Corcos model. The wavenumber-frequency spectral densities numerically computed from the discrete eigenfunctions compared well with Martin{close_quote}s ...

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)

Partial bladder outlet obstruction (PBOO) induces remodeling of urinary bladder smooth muscle (detrusor). We demonstrate an increase in bladder wall mass, muscle bundle size, and a threefold increase...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The author describes the layout of the environmental monitoring scheme at Devco's No. 26 Colliery in Canada, which includes wall face ventilation, fan performance, and methane drainage monitoring. He gives details of the sensors, outstations, and the surface control room.

UK PubMed Central (United Kingdom)

The properties of an atypical Brucella strain isolated from lymph node tissue of a cow slaughtered as a brucellosis reactor were examined. The organism was Gram negative and highly pleomorphic, existing...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In Canada, the cost of heating is a major expense in the operation of greenhouses in the winter season, inhibiting greenhouse production in winter months in most part of the country. Alternative energy sources, such as solar energy and biomass energy may offer an economically feasible heating alternative. A solar energy greenhouse technology developed in northern China for winter vegetable production has demonstrated good potential for Manitoba winter conditions. The design and performance of solar energy greenhouses depend on the geographical location. Therefore, in order to optimize the design of solar greenhouses with respect to the latitude of the location for maximum solar radiation gain, a theoretical analysis was performed that analyzed parameters such as greenhouse length and the roof slope. This paper described the methodology of the study, including a description of solar energy greenhouses; the energy of solar radiation; shading of the north roof; shading of the end ...

UK PubMed Central (United Kingdom)

BackgroundGastrointestinal stromal tumors (GISTs) are mesenchymal tumors that develop in the wall of the gastrointestinal tract and their diagnosis during pregnancy or puerperium...Full Text Available

UK PubMed Central (United Kingdom)

Unless relaxation of the stringent response is achieved, all nongrowing bacteria rapidly develop resistance to autolysis induced by a variety of agents, including all classes of cell wall synthesis...Full Text Available

Science.gov (United States)

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

Science.gov (United States)

An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of a gas turbine blade wall is presented. Three configurations were investigated, namely a slot jet, a round ...

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

The curvature elastic modulus (bending stiffness) of stearoyloleoyl phosphatidylcholine (SOPC) bilayer membrane is determined from membrane tether formation experiments. R. E. Waugh and R. M. Hochmuth...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundWide resection with tumor-free margins is necessary in soft-tissue sarcomas to minimize local recurrence and to contribute to long-term survival. Information about treatment...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Cyclothiazomycin B1 (CTB1) is an antifungal cyclic thiopeptide isolated from the culture broth of Streptomyces sp. HA 125-40. CTB1 inhibited the growth of several filamentous fungi including plant pathogens along with swelling of hyphae and spores. The antifungal activity of CTB1 was weakened by hyperosmotic conditions, and hyphae treated with CTB1 burst under hypoosmotic conditions, indicating increased cell wall fragility. CTB1-sensitive fungal species contain high levels of cell wall chitin and/or chitosan. Unlike nikkomycin Z, a competitive inhibitor of chitin synthase (CHS), CTB1 did not inhibit CHS activity. Although CTB1 inhibited CHS biosynthesis, the same result was also obtained with a non-specific proteins inhibitor, cycloheximide, which did not reduce cell wall rigidity. These ...

UK PubMed Central (United Kingdom)

The incidence of arrhythmias after acute myocardial infarction of the inferior wall varies with the affected segment and increases when there is right ventricular involvement. This paper provides a...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Hollow needles made of an electrically conducting material are attached by hinges in the openings of the perforated end of an insert in order to intensify heat and mass transfer. The free sections of the needles are placed outside the insert, and a wick is placed on the wall of the frame in the condensation area. The wick overlaps the inlet openings of the insert.

Energy Technology Data Exchange (ETDEWEB)

A safety analysis code to design a pressurized water reactor and to obtain the licenses including entire proprietary rights is under development in domestic R and D project. The tasks of KAERI is to develop the constitutive relations including models for defining flow regimes and flow regime related models for inter-phase friction, wall frictions, wall heat transfer, and interphase heat and mass transfer in the two-phase three-field equations. In this paper, the process will be presented for choosing the best flow regime maps which occur in gas-liquid two-phase flow in horizontal and vertical tubes.

CERN Document Server

Charged particle beams in circular accelerators couple with their surroundings through induced electromagnetic fields. This interaction can be described by so-called coupling impedances. In the frequency domain the impedance in connection with the bunch spectrum allows for stability analysis and estimates. However, for simulation codes one usually needs the wakefunction, the equivalent of the impedance in time domain. Recently the transverse impedance of a cylindrical pipe with arbitrary surface impedance was given by L. Vos. An expression for the wakefunction of this transverse resistive wall impedance with inductive bypass is derived here.

International Nuclear Information System (INIS)

Natural convection of vaporizing Deuterium at 25 K transports the heat generated in the moderator cell of the cold neutron source to a He cooled condenser. The thermohydraulics of this thermosiphon were precalculated and the results verified by experiments in a 1:1 model using D_2 as fluid. The experimental results show that the thermosiphon operates stable. The demanded liquid content of the cell as well as wall temperatures below 50 K can be ensured by a proper design of the cell outlet flow geometry. A 7 min. loss of cryogenic power results in transient temperatures of the cell wall of not more than 300 K.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

The biodegradation of ring-"1"4C- and methyl-"1"4C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO_2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.

Energy Technology Data Exchange (ETDEWEB)

This reports is a literature survey on models and correlations for determining flow pattern that are used to simulate thermal-hydraulics in nuclear reactors. Determination of flow patterns are a basis for obtaining physical values of wall/interfacial friction, wall/interfacial heat transfer, and droplet entrainment/de-entrainment. Not only existing system codes, such as RELAP5-3D, TRAC-M, MARS, TRACE, CATHARE) but also up-to-date researches were reviewed to find models and correlations

International Nuclear Information System (INIS)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively. (author). 4 refs.

International Nuclear Information System (INIS)

A safety analysis code, named as SPACE, for a pressurized water reactor is under development to obtain a licensing to be used for the PWR design and to hold entire proprietary rights. The task of KAERI is to develop the physical models and correlations which are required to solve the field equations. It can be divided into four parts; i) flow regime determination, ii) wall heat transfer, iii) wall and interfacial friction, iv) interfacial heat and mass transfer. This paper will describe the process to develop the models for the two-phase flow regime maps in the horizontal and vertical pipes.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

An anaerobic fermenter-decanter for the purification of residual water from the sugar industry, with recovery of methane, consists of a tank with inclined walls, with a central agitator on a vertical shaft. A flexible cover anchored by its periphery to the walls of the tank and totally submerged forms a collecting pocket for the fermentation gases. The water to be purified is introduced, after being heated to about 35, towards the bottom of the tank near the agitator. A metal collecting bell with submerged edges and with the shaft of the agitator passing axially through it is connected by its edges to a central opening of the cover. The purification yields may exceed 90%.

Energy Technology Data Exchange (ETDEWEB)

The process operation of the hot wall vapor deposition method, formation of dry organic thin film and the control of molecular arrangement were described. This equipment included a substrate on the upper end of the hot wall tube and the vapor source at the lower end. The remarkable features are the hot wall tube which plays the role to hold vaporizing molecules to the high temperature and to transport molecules, and the flip flop mechanism which gives some idle period for the molecular vaporization by shutter closing. Several experiments were carried out by using stearic acid and by changing the distance S from the upper end of hot wall quartz tube to the substrate, the furnace temperature T{sub f} and the substrate temperature T{sub s}. When T{sub f} is equal to or less than the melting point of stearic acid, molectles are preferentialy made to vertical arrangement. In the case of T{sub f} more than ...

International Nuclear Information System (INIS)

The aim of this study was to compare multidetector-row computed tomography (MDCT) findings between cases of sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and infiltrative extrahepatic cholangiocarcinoma (IEC). We retrospectively assessed MDCT findings from 16 IEC cases and 13 SC-AIP cases. MDCT findings were analyzed with regard to location, length, wall thickness, contour, stricture wall enhancement pattern, proximal duct diameter, and the presence of diffuse concentric thickening in the proximal duct and gallbladder wall thickness. Stricture length, stricture wall thickness, and proximal duct diameter were significantly smaller for SC-AIP than for IEC: 19.3#+-#8.7 vs. 31.8#+-#12.0 mm (P=0.004), 2.1#+-#1.3 vs. 4.1#+-#1.3 mm (P<0.001), and 9.2#+-#3.9 vs. 13.3#+-#5.0 mm (P=0.012), respectively. SC-AIP was correlated with stricture location in both the intrapancreatic and hilar hepatic ...

International Nuclear Information System (INIS)

1975. USSR Zabrodskij, VA Nedavnij, SN INIS-mf--3677. Available from

Science.gov (United States)

... Attributes and limitations of the charac- terization framework are illustrated through comparison with experimental PLZT data. ...

Energy Technology Data Exchange (ETDEWEB)

A database has been developed to contain the disposal limits for the E-Area Low Level Waste Facility (ELLWF). This database originates in the form of an EXCEL{copyright} workbook. The pertinent sheets are translated to PDF format using Adobe ACROBAT{copyright}. The PDF version of the database is accessible from the Solid Waste Division web page on SHRINE. In addition to containing the various disposal unit limits, the database also contains hyperlinks to the original references for all limits. It is anticipated that database will be revised each time there is an addition, deletion or revision of any of the ELLWF radionuclide disposal limits.

Energy Technology Data Exchange (ETDEWEB)

In the context of safety assessment of radioactive waste repositories, complex radionuclide transport models covering key safety-relevant processes play a major role. In recent Swiss safety assessments, such as Kristallin-I, an important drawback was the limitation in geosphere modelling capability to account for geosphere heterogeneities. In marked contrast to this limitation in modelling capabilities, great effort has been put into investigating the heterogeneity of the geosphere as it impacts on hydrology. Structural geological methods have been used to look at the geometry of the flow paths on a small scale and the diffusion and sorption properties of different rock materials have been investigated. This huge amount of information could however be only partially applied in geosphere transport modelling. To make use of these investigations the 'PICNIC project' was established as a joint cooperation of PSI/Nagra and ...

Energy Technology Data Exchange (ETDEWEB)

A system is described adapted for alternative use as a diverter or a blowout preventer for a bottom supported drilling rig and adapted for connection to a permanent housing attached to rig structural members beneath a drilling rig rotary table, the permanent housing having an outlet connectable to a rig fluid system flow line. The system consists of: a fluid flow controller having a controller housing with a lower cylindrical opening and an upper cylindrical opening and a vertical path therebetween and a first outlet passage and a second outlet passage provided in its wall, a packing element disposed within the controller housing, and annular piston means adapted for moving from a first position to a second position, whereby in the first position the piston means wall prevents interior fluid from communicating with the outlet passages in the controller housing wall and in the second position the piston means ...

Energy Technology Data Exchange (ETDEWEB)

Small circular and noncircular channels are representative of flow passages in compact evaporators and condensers. This paper describes results of an experimental study on heat transfer to the flow boiling of refrigerant- 12 in a small circular tube of diameter = 2.46 mm. The objective of the study was to assess the effect of channel size on the heat transfer coefficient and to obtain additional insights relative to the heat transfer mechanisms. The flow channel was made of brass and had an overall length of 0.9 m. The channel wall was electrically heated, and temperatures were measured on the channel wall and in the bulk fluid stream. Voltage taps were located at the same axial locations as the stream thermocouples to allow testing over an exit quality range of 0.21 to 0.94 and a large range of mass flux (63 to 832 kg/m{sup 2}s) and heat flux (2.5 to 59 kW/m{sup 2}). Saturation pressure was nearly constant, averaging 0.82 MPa for most of the ...

International Nuclear Information System (INIS)

In this paper, a phenomenological model of the thermal hydraulics of convective boiling in the post-critical-heat-flux (post-CHF) regime is developed and discussed. The model was implemented in the TRAC-PF1/MOD2 computer code (an advanced best-estimate computer program written for the analysis of pressurized water reactor systems). The model was built around the determination of flow regimes downstream of the quench front. The regimes were determined from the flow-regime map suggested by Ishii and his coworkers. Heat transfer in the transition boiling region was formulated as a position-dependent model. The propagation of the CHF point was strongly dependent on the length of the transition boiling region. Wall-to-fluid film boiling heat transfer was considered to consist of two components: first, a wall-to-vapor convective heat-transfer portion and, second, a wall-to-liquid heat transfer representing ...

CERN Document Server

Limiters are nonlinear hybridization techniques that are used to preserve positivity and monotonicity when numerically solving hyperbolic conservation laws. Unfortunately, the original methods suffer from the truncation-error being first-order accurate at all extrema despite the accuracy of the higher-order method. To remedy this problem, higher-order extensions were proposed that relied on elaborate analytic and geometric constructions. Since extremum-preserving limiters are applied only at extrema, additional computational cost is negligible. Therefore, extremum-preserving limiters ensure higher-order spatial accuracy while maintaining simplicity. This report presents higher-order limiting for (i) computing van Leer slopes and (ii) adjusting parabolic profiles. This limiting preserves monotonicity and accuracy at smooth extrema, maintains stability in the presence of ...

Energy Technology Data Exchange (ETDEWEB)

Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was ...

International Nuclear Information System (INIS)

Considerations for longevity of nuclear facilities and ease of decommissioning are of great importance for future nuclear power plants. To this end, a concept of an optimal structural concept for nuclear reactor buildings has been studied: the main feature of this concept is to utilize large-sized, light weight prefabricated members with ultrahigh strength materials. The following two items have been selected to study the prospective structure: (1) Applicability of ultrahigh strength materials for reinforced concrete shear walls (2) Construction using large sized prefabricated members As the first step (1), material and structural tests using ultrahigh strength materials, and the subsequent analysis of those tests for reinforced concrete shear walls, has been conducted. The positive results of this study show a bright future for the use of ultrahigh strength materials for the reinforced concrete shear walls of nuclear ...

International Nuclear Information System (INIS)

Since the first round of conceptual fusion reactor designs in 1973 - 1974, there has been considerable progress in design improvement. Two recent tokamak designs of the Wisconsin and Culham groups, with increased plasma beta and wall loading (power density), lead to more compact reactors with easier maintenance. The Reference Theta-Pinch Reactor has undergone considerable upgrading in the design of the first wall insulator and blanket. In addition, a conceptual homopolar energy storage and transfer system has been designed. In the case of the mirror reactor, there are design changes toward improved modular construction and ease of handling, as well as improved direct converters. Conceptual designs of toroidal-multiple-mirror, liner-compression, and reverse-field pinch reactors are also discussed. A design is presented of a toroidal multiple-mirror reactor that combines the advantages of steady-state operation and high-aspect ratio. The ...

Energy Technology Data Exchange (ETDEWEB)

Laboratory experiments were conducted to simulate the transfer of acidic THOREX waste from Tank 8D-4 into the alkaline PUREX waste in Tank 8D-2 at West Valley. The purpose of the experiments was to explore means of minimizing the production of nitric oxide (NO) gas during mixing of the two wastes and to assess the potential for the gas to further react in the vapor space possibly leading to enhanced corrosion of the tank walls. Forty one THOREX/PUREX mixing tests were conducted to explore the effects of stirring rate, pH, THOREX addition rate, THOREX or PUREX dilution, and temperature. The two most important criteria for minimizing NO production were to maintain some degree of agitation and the keep the pH in the PUREX high, preferably >12. Steel corrosion tests were performed in the presence of low partial pressures of NO{sub 2} and liquid water or water vapor. The NO{sub 2} (from oxidation of NO in the vapor space) concentrations were representative of those ...

Energy Technology Data Exchange (ETDEWEB)

Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. The cases of GDH impact on an adjacent GDH and its attached piping are investigated in this paper. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. The results of the study indicate that a whipping GDH pipe would ...

Energy Technology Data Exchange (ETDEWEB)

This patent describes a system adapted for alternative use as a diverter or a blowout preventer for a bottom supported drilling rig and adapted for positioning beneath a rotary table of the drilling rig, the system comprising: a fluid flow controller having a controller housing with a lower opening and an upper opening and a vertical flow path therebetween and an outlet passage provided in its housing wall, and at least two bases. A method is described for installing a system adapted for alternative connection as a diverter or a blowout preventer for a bottom supported drilling rig positioned beneath a rotary table of the drilling rig after structural casing has been set in a borehole. The method comprises: positioning a first telescoping spool having a lower end and an upper end below the rotary table, the first spool having a first base disposed at its upper end, the first base having a port disposed in its wall; aligning a fluid flow ...

International Nuclear Information System (INIS)

We compared the values of the myocardial thickness and the left ventricle diameters measured with MRI and echocardiography. The ejection fraction was compared in MRI and ventriculography. 34 patients with different heart dysfunctions were examined with MRI (FISP 2D sequence). 26 of them were also studied by echocardiography and 20 by biplane cine-ventriculography. The enddiastolic thicknesses of the left ventricular postero-lateral wall and of the septum interventriculare were measured on short axis images. An ellipsoidal modell was used for volume calculation and ejection fraction. Correlation of MRI values of thickness and ejection fraction with echocardiographi and angiographi showed r>0,8. As known for 1.56 T Imagers, the myocardial thickness in MRI was underestimated compared to echocardiography (1.4 mm#+-#1.7). The ejection fraction was underevaluated compared to ventriculography (4.5%#+-#10.1). MRI (1.0 T) accurately measures ventricular ...

International Nuclear Information System (INIS)

Throughout the DOE complex there are numerous facilities that handle hazardous and radioactive waste solutions. Due to the hazardous constituents of the mixed waste, secondary containment of tank systems and their ancillary piping, in accordance with Resource Conservation and Recovery Act, is a concern for such existing facilities. The Idaho Division of Environmental Quality was petitioned in 1990 for an Equivalent Device determination regarding secondary containment of waste lines embedded in interior concrete walls. The petition was granted; however, it expires in 1996. To address the secondary containment issue, additional studies were undertaken. One study verified the hypothesis that an interior wall pipe leak would follow the path of least resistance through the naturally occurring void found below a rigidly supported pipe and pass into an adjacent room where detection could occur, before any significant deterioration of the concrete ...

British Library Electronic Table of Contents (United Kingdom)

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

British Library Electronic Table of Contents (United Kingdom)

A highly sensitive and stable tris(2,2prime-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)32+ immobilized in the ECL sensor by adsorption of Ru(bpy)32+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-...

Energy Technology Data Exchange (ETDEWEB)

The buckling behaviors of double-walled carbon nanotubes (DWCNTs) under torsion are investigated by using molecular dynamics (MD) simulations. The effect of length on the torsional buckling behaviors of DWCNTs is examined for the first time. The simulation results show that the DWCNTs experience gradual or simultaneous buckling deformations depending on their lengths. In addition, the effect of the inner tube in a DWCNT on its torsional buckling behavior is also examined. The presence of the inner tube triggers van der Waals (vdW) interactions between it and the outer tube and thus leads to a stiffening effect of the DWCNT against torsional deformation. Whether the ends of the inner tube are free or fixed and whether it is subject to a torque or not, the critical torque and the critical torsional angle of the outer tube are only marginally affected.

Energy Technology Data Exchange (ETDEWEB)

Results are presented from a numerical model of the steady-state energy transfer in molten-salt-in-tube solar cavity receivers that includes convective energy transfer at a local (spatially resolved) level. Molten salt energy absorption and gray radiative transfer between all cavity surfaces are also included. This model is applied to the Molten Salt Subsystem Component Test Experiment (MSS/CTE) cavity receiver. Results for this receiver indicate the global (entire cavity) receiver thermal efficiency is invariant within a few percent to most parameters investigated, although front surface temperatures of the nonabsorbing walls vary considerably, and are particularly sensitive to the type of convective submodel used. Absorption efficiencies indicate the effects of the cavity enclosure environment. For all conditions investigated, tube inner wall temperatures remain under 855 K, ensuring that the salt remains chemically stable.

Energy Technology Data Exchange (ETDEWEB)

Inactive cells of Rhizopus arrhizus have been documented to exhibit a high thorium biosorptive uptake (170 mg/g) from aqueous solutions. The mechanism of thorium sequestering by this biomass type was investigated following the same method as for the uranium biosorption emchanism. The thorium sequestering mechanism appeared somewhat different from that of uranium. Experimental evidence is presented which indicates that, at optimum biosorption pH (4), thorium coordinates with the nitroge of the chitin cell wall network and, in addition, more thorium is adsorbed by the external section of the fungal cell wall. At pH 2 the overall thorium uptake is reduced. The kinetic study of thorium biosorption revealed a very rapid rate of uptake. Unlike uranium at optimum solution pH, Fe/sup 2 +/ and Zn/sup 2 +/ did not interfere significantly with the thorium biosorptive uptake capacity of R. arrhizus.

International Nuclear Information System (INIS)

Test Blanket Modules (TBM) will be tested in ITER to verify the capability of tritium breeding and recovery and the extraction of thermal energy suitable for the production of electricity. A Helium Cooled Solid Breeder (HCSB) TBM has been developed in Korea to accomplish these goals. Reduced Activation Ferritic/Martensitic (RAFM) steel has been chosen as the primary candidate structural material for Korean TBM. Due to the complexity of the First wall (FW) and Side wall (SW), it is necessary to develop various joining technologies, such as Hot Isostatic Pressing (HIP), Electron Beam Welding (EBW) and Tungsten Inert Gas (TIG) welding, for the successful fabrication of TBM. In this study, the mechanical properties of TIG welded RAFM steel were investigated. Various mechanical tests of TIG-welded RAFM steel were performed to obtain the optimized TIG welding process for RAFM steel

CERN Document Server

In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.

CERN Document Server

The physical foundations of a variety of emerging technologies --- ranging from the applications of quantum entanglement in quantum information to the applications of nonequilibrium bulk and interface phenomena in microfluidics, biology, materials science, energy engineering, etc. --- require understanding thermodynamic entropy beyond the equilibrium realm of its traditional definition. This paper presents a rigorous logical scheme that provides a generalized definition of entropy free of the usual unnecessary assumptions which constrain the theory to the equilibrium domain. The scheme is based on carefully worded operative definitions for all the fundamental concepts employed, including those of system, property, state, isolated system, environment, process, separable system, system uncorrelated from its environment, and parameters of a system. The treatment considers also systems with movable internal walls and/or semipermeable walls, with ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Aims: To develop a new nano composite of multi walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity. Methods and Results: A novel antimicrobial nanocomposite [MWNT epilson polylysine (MEPs)] was synthesized via covalent attachment of epilson polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV visible spectra and Fourier transform infrared spectra (FT IR) investigations indicate that MEPs is stable, with epilson polylysine leaching effectively eliminated. When compared to MWNTs, the new nano composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l 1 suspensions, significant increases of 72 1, 64 5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs...

Energy Technology Data Exchange (ETDEWEB)

The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5-6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.

International Nuclear Information System (INIS)

The EU-home team is in charge of the R and D related to the ITER baffle first wall. Five small-scale mock-ups, using Be, CFC and W tiles and different armour/heat-sink material joints under development, have been fabricated and thermomechanically tested in FE200 (Le Creusot) and JUDITH (Juelich) electron beam facilities. The small-scale mock-ups have been submitted to thermo-mechanical fatigue tests (up to failure using accelerating techniques). The objective was to determine the performances of the armour material joints under high heat flux cycles. (orig.)

Science.gov (United States)

The flow and heat transfers associated with a plane laminar flow past a forward-facing step were analyzed using a power-law numerical scheme combined with a false vorticity-stream function approach. To improve the traditional wall-vorticity boundary condition, a novel method, based on an accurate description of the nonslip wall condition, was developed and utilized. The convergence for a 56 x 49 grid system was obtained in about 350 iterations. The computed reattachment distances in the upper separated region agree with the available experimental data for a blunt plate. The heat transfer augmentation is significant across the step; however, it is counterbalanced by the deterioration of heat transfer immediately upstream of the step.

British Library Electronic Table of Contents (United Kingdom)

An experimental study was performed to investigate the heat transfer characteristics of the mixed convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities (10, 20 and 30 PPI) were situated. A uniform heat flux was applied at all of the bounding walls of the channel. For each of three values of the uniform heat flux, temperatures were measured on the entire surfaces of the walls. Results for the average and local Nusselt numbers are presented as functions of the Reynolds and Richardson numbers. The Reynolds number based on the channel height of the rectangular channel was varied from 600 to 33000, while the Richardson number ranged from 0.02 to 103, extending over forced, mixed and natural convection. Second important parameter that in...

International Nuclear Information System (INIS)

A linear diffusion model serves as the basis for determination of an effective radon diffusion coefficient in concrete. The coefficient was needed to later allow quantitative prediction of radon accumulation within and behind concrete walls after application of an impervious radon barrier. A resolution of certain discrepancies noted in the literature in the use of an effective diffusion coefficient to model diffusion of a radioactive gas through a porous medium is suggested. An outline of factors expected to affect the concrete physical structure and the effective diffusion coefficient of radon through it is also presented. Finally, a field method for evaluating effective radon diffusion coefficients in concrete is proposed and results of measurements performed on a concrete foundation wall are compared with similar published values of gas diffusion coefficients in concrete. (author).

Energy Technology Data Exchange (ETDEWEB)

The two-sonde neutron-logging device RKS-2 registers the ratios of the indications of two sondes and is scaled in units representing the total water content of pure limestone when saturated with fresh water. When analyzing the results of the measurements in real wells, it is necessary to calculate the effect of well- and strata conditions on the results of porosity determination. The results of simulated measurements are presented, on the basis of which correction factors are immediately determined for the calculation of the effect of the diameter of the well, and the effect of the mud cake on the well wall. A nomogram is constructed and substantiated; its purpose is the calculation of the effect of the following on the RKS-2 indication: the diameter of the well, the mud cake on the well wall, the density of the drilling solution, temperature, pressure in the well, and the lithology of the rock.

International Nuclear Information System (INIS)

The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10"-"1"6 m"2. Areas free of surface defects had 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. This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.).

Energy Technology Data Exchange (ETDEWEB)

Field investigations of major and damaging ice jamming on the Saint John River at Dickey, Maine , and at Sainte-Anne de-Madawaska, New Brunswick, in 1991, were described. The investigations included measurement of water surface profiles and shear wall heights at both sites. The measurements were supplemented by information from local observers and data collection agencies. Using a simplified equilibrium analysis, ice jam thickness and water level at the Dickey site was found to be generally in agreement with observed values. At Sainte-Anne-de-Madawaska sufficient data was obtained to construct and calibrate the numerical model RIVJAM which determined the configuration of the jam in nonequilibrium reaches. Use of the model enabled the successful reproduction of a measured water profile along the jam and the prediction of the approximate thickness of the jam, which was generally less than the measured shear wall height. 14 refs., 11 figs.

UK PubMed Central (United Kingdom)

G-protein-coupled receptor signalling has been suggested to be voltage dependent in a number of cell types; however, the limits of sensitivity of this potentially important phenomenon are unknown. Using...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundIn a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities....Full Text Available

UK PubMed Central (United Kingdom)

Nutrient transport affinities of nutrient-starved microbial populations were measured as initial slopes of plots of limiting-nutrient transport rates versus extracellular limiting-nutrient concentrations....Full Text Available

Science.gov (United States)

This report estimates the economic and financial effects of compliance with the proposed effluent limitations guidelines and standards for the Centralized Waste Treatment (CWT) industry. The Environmental Protection Agency (EPA) has measured these impacts...

Science.gov (United States)

This section presents background information supporting the development of effluent limitations guidelines and standards for the concentrated aquatic animal production (CAAP) point source category. Section 1.1 presents the legal authority to regulate the ...

Science.gov (United States)

This document presents regulations and research support the EPA`s effluent limitations for the paving and roofing materials point source category.

Science.gov (United States)

This analysis, submitted in support of proposed effluent limitations guidelines and standards for the centralized waste treatment (CWT) industry, investigates the cost-effectiveness of 24 regulatory options, representing all possible combinations of nine ...

UK PubMed Central (United Kingdom)

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

Science.gov (United States)

... Development Document for Proposed Effluent Limitations Guidelines and Standards for the Shipbuilding and Repair Point Source Category (Draft ...

International Nuclear Information System (INIS)

Object: To limit the discharge amount of reactor water in a primary system at the time of scram to prevent excessive outflow of reactor water outside the system. Structure: A signal from an upper limit position indicator detects the fact that control rods are completely inserted when the reactor is urgently stopped and the detection signal causes a valve in an outflow line of the discharge water from a control rod driving mechanism to be closed to limit the amount of discharge flown into the scram discharge vessel, thus preventing outflow of reactor water in the primary system after the scram has been initiated. (Kamimura, M.).

CERN Document Server

We give a general local central limit theorem for the sum of two independent random variables, one of which satisfies a central limit theorem while the other satisfies a local central limit theorem with the same order variance. We apply this result to various quantities arising in stochastic geometry, including: size of the largest component for percolation on a box; number of components, number of edges, or number of isolated points, for random geometric graphs; covered volume for germ-grain coverage models; number of accepted points for finite-input random sequential adsorption; sum of nearest-neighbour distances for a random sample from a continuous multidimensional distribution.

Science.gov (United States)

No abstract available.

Science.gov (United States)

... populations ..... 63 34 Vertebral ultimate compressive strength for various populations ..... 64 35 ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes a maintenance problem in a fusion power plant. The problem is to specify which life limited parts should be replaced when there is an opportunity. The objective is to minimize the cost rate of replacement parts and of maintenance actions while satisfying a power plant availability constraint. The maintenance policy is to look ahead and replace all parts that will reach their life limits within a time called a screen. Longer screens yield greater system availabilities because more parts are replaced prior to their life limits.