Energy Technology Data Exchange (ETDEWEB)

The goal of assembly sequencing is to plan a feasible series of operations to construct a product from its individual parts. Previous research has thoroughly investigated assembly sequencing under the assumption that parts have nominal geometry. This paper considers the case where parts have toleranced geometry. Its main contribution is an efficient procedure that decides if a product admits an assembly sequence with infinite translations that is feasible for all possible instances of the components within the specified tolerances. If the product admits one such sequence, the procedure can also generate it. For the cases where there exists no such assembly sequence, another procedure is proposed which generates assembly sequences that are feasible only for some values of the toleranced dimensions. If this procedure produces no such sequence, ...

International Nuclear Information System (INIS)

A nonlinear dynamic transient analysis merging hand calculations and the NASTRAN structural analysis computer code was conducted for a Fast Flux Test Facility in-reactor test assembly during an extremely unlikely design basis accidental event which is considered a Hypothetical Core Disruptive Accident (HCDA). The finite element modeling of the problem took advantage of NASTRAN's versatility to create loads and nonlinear elements not previously found in NASTRAN's library. The structural criteria for the test assembly to withstand an HCDA stipulates that the test assembly and its spoolpiece shall remain integral with the reactor head such that missiles are not generated.

British Library Electronic Table of Contents (United Kingdom)

To study interactions between plants and plant-parasitic nematodes, several omics studies have nowadays become extremely useful. Since most data available so far is derived from sedentary nematodes, we decided to improve the knowledge on migratory nematodes by studying the transcriptome of the nematode Pratylenchus coffeae through generating expressed sequence tags (ESTs) on a 454 sequencing platform. In this manuscript we present the generation, assembly and annotation of over 325,000 reads from P. coffeae. After assembling these reads, 56,325 contigs and singletons with an average length of 353bp were selected for further analyses. Homology searches revealed that 25% of these sequences had significant matches to the Swiss-prot/trEMBL database and 29% had significant matches in nematode E...

Energy Technology Data Exchange (ETDEWEB)

Since the first operation of nuclear steam generator early 1960s, its performance requirements have been met but the steam generator problems have been met but the steam generator problems have been major cause of reducing the operational reliability, plant safety and availability. U-tube assembly of steam generator forms the primary system pressure boundary of the plant and have experienced several types of tube degradation problems. Tube failure and leakage resulting from the degradation will cause radioactive contamination of secondary system by the primary coolant, and this may lead to unplanned plant outages and costly repair operations such as tube plugging or steam generator replacement. For the case of steam generators for heavy water reactors, e.g. Wolsong 2, 3, and 4 NPP, a high cost of heavy water will be imposed additionally. ...

CERN Document Server

Safe operation of research reactors and critical assemblies

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Self-assembled quantum dots (QDs) are envisioned as building blocks for realization of novel nanoelectronic devices, for which the site-selective growth is highly desirable. This thesis presents a successful route toward selective positioning of self-assembled InAs QDs on patterned GaAs surface by combination of in situ focused ion beam (FIB) implantation and molecular beam epitaxy (MBE) technology. First, a buffer layer of GaAs was grown by MBE before a square array of holes with a pitch of 1-2 #mu#m was fabricated by FIB implantation of Ga and In, ions respectively. Later, an in-situ annealing step followed by InAs deposition was performed. The InAs QDs were preferentially formed in the holes generated by FIB. The influence of ion dose, annealing parameters and InAs amount was investigated in this work. With optimized parameters, more than 50 % single dot occupancy per hole is achieved. Furthermore, the photoluminescence ...

UK PubMed Central (United Kingdom)

ConspectusSelf-assembly allows for the preparation of highly complex molecular and supramolecular systems from relatively simple starting materials. Typically, self-assembled...Full Text Available

Science.gov (United States)

Not Available

International Science & Technology Center (ISTC)

Behavior of Nuclear Reactor Fuel Assembly Materials during Their Long-Term Dry Storage

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the work performed by Honeywell during the October 2001 to December 2001 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. The conceptual and demonstration system designs were proposed and analyzed, and these systems have been modeled in Aspen Plus. Work has also started on the assembly of dynamic component models and the development of the top-level controls requirements for the system. SOFC stacks have been fabricated and performance mapping initiated.

Energy Technology Data Exchange (ETDEWEB)

This invention is a manufacturing method of a metal-hydrogen alkali battery cell consisting of a positive electrode of metal oxides, alkaline electrolyte solution and a separator containing an amide-radical, wherein the above treating solution is aqueous solution of KOH (or NaOH) which is heated at least at 40 centigrade and the separator is first immersiion-treated and then water-washed and dried. The amide-radical-containing separaator uses a nylon non-woven fabrics. Average molecular weight of nylon 66 is 12,000 - 20,000. In this invention, in order to improve the storage ability and the cycle characteristics which are caused by corrosion of a separator which takes place in the cell after its assembly, the separator is immersed in a hot alkali in order to obtain a non-woven fabric of nylon 66 consisting of alkali-stable high molecular weight portion, which is assembled into a battery. By this, the dissolving of the non-woven fabric and the ...

Environmental Research Database

Objectives1. To develop new photoactive materials and fabricate demonstration QD (quantum dot) solar cells. This will be achieved by:~%~1.1. Materials preparation and characterisation of QD/polymer systems~%~1.2. Optimising structures of QDs, nanorods and polymer for quantum yield and charge transfer~%~1.3 Fabricating demonstration QD/polymer solar cells and measuring power conversion efficiencies~%~2. To demonstrate multiexciton generation (MEG) and harvesting within nanostructured QDs. This will involv [continued...]DescriptionWidespread implementation of photovoltaic electricity to meet changing energy demands requires a step-change in the cost of photovoltaic power. This proposal assembles a consortium of chemists, physicists, materials scientists and electrical engineers from The University of Manchester and Imperial College London to address this need through the development of new low-cost, high-efficiency, demonstration solar cells for ...

Science.gov (United States)

An enantiocontrolled route to aziridinomitosenes had been developed from l-serine methyl ester hydrochloride. The tetracyclic target ring system was assembled by an internal azomethine ylide cycloaddition reaction based on silver ion-assisted intramolecular oxazole alkylation and cyanide-induced ylide generation via a labile oxazoline intermediate (62 to 66). Other key steps include reductive detritylation of 26, methylation of the N-H aziridine 56, oxidation of the sensitive cyclohexenedione 68 to quinone 70, and carbamoylation using Fmoc-NCO. Although the aziridinomitosene tetracycle is sensitive, a range of protecting group manipulations and redox chemistry can be performed if suitable precautions are taken. A study of DNA alkylation by the first C-6,C-7-unsubstituted aziridinomitosene 11a has been carried out, and evidence for DNA cross-link formation involving nucleophilic addition to the quinone subunit is described. PMID:14677970

International Nuclear Information System (INIS)

The efficiency of electric power generation by dye-sensitized mesoscopic photovoltaic cells has been progressing steadily over the last years reaching now 11% in full sunlight. An important question for practical applications concerns the stability of these devices under prolonged exposure to light or heat. Strikingly stable operation can be obtained by judicious selection of the sensitizer, electrolyte and sealant rendering feasible a service life of at least 20 years under normal outdoor conditions. The sensitizer playing a central role in the light energy conversion process, we analyze the kinetic requirements for it to sustain the required one hundred million turnovers. We also review recent results on the use of self-assembled monolayers of amphiphilic sensitizers and co-adsorbents to enhance the thermal robustness of the device. (author)

Energy Technology Data Exchange (ETDEWEB)

Natural circulation experiments carried out in the REWET-III facility in 1985 have been used for RELAP5/MOD2 assessment. The REWET-III facility is a scaled-down model of VVER-440 type reactors. The facility consists of a pressure vessel in which the downcomer is simulated with an external pipe assembly, hot and cold legs with loop seals and a horizontal steam generator. The volume scaling factor compared to the reference reactor is 1:2333. The present paper summarizes the experiences gained in the RELAP5/MOD2 calculations of selected REWET-III single- and two-phase natural circulation experiments. The code's ability to represent the main phenomena of experiments in both cases was satisfactory.

International Nuclear Information System (INIS)

Natural circulation experiments carried out in the REWET-III facility in 1985 have been used for RELAP5/MOD2 assessment. The REWET-III facility is a scaled-down model of VVER-440 type reactors. The facility consists of a pressure vessel in which the downcomer is simulated with an external pipe assembly, hot and cold legs with loop seals and a horizontal steam generator. The volume scaling factor compared to the reference reactor is 1:2333. The present paper summarizes the experiences gained in the RELAP5/MOD2 calculations of selected REWET-III single- and two-phase natural circulation experiments. The code's ability to represent the main phenomena of experiments in both cases was satisfactory.

Science.gov (United States)

A silicon solar cell assembly comprising a large, thin silicon solar cell bonded to a metal mount for use when there exists a mismatch in the thermal expansivities of the device and the mount.

International Nuclear Information System (INIS)

Reactor COre Protection System (RCOPS), an advanced core protection calculator system, is a digitized one which provides core protection function based on two reactor core operation parameters, Departure from Nucleate Boiling Ratio (DNBR) and Local Power Density (LPD). It generates a reactor trip signal when the core condition exceeds the DNBR or LPD design limit. It consists of four independent channels adapted a two-out-of-four trip logic. System configuration, hardware platform and an improved algorithm of the newly designed core protection calculator system are described in this paper. One channel of RCOPS was implemented as a single channel facility for this R and D project where we performed final integration software testing. To implement custom function blocks, pSET is used. Software test is performed by two methods. The first method is a 'Software Module Test' and the second method is a 'Software Unit Test'. New features include improvement of core thermal ...

Science.gov (United States)

A paraboloidal dish solar thermal power plant produces electrical energy by a two-step conversion process. The collector subsystem is composed of a two-axis tracking paraboloidal concentrator and a cavity receiver. The concentrator focuses intercepted sunlight (direct, normal insolation) into a cavity receiver whose aperture encircles the focal point of the concentrator. At the internal wall of the receiver the electromagnetic radiation is converted to thermal energy. A heat engine/generator assembly, which is mounted directly behind th receiver, then converts the thermal energy captured by the receiver to electricity. Developmental activity has been concentrated on relatively small power modules which employ 11- to 12-m-diam dishes to generate nominal power levels of approximately 20 kW. A comparison of advanced heat engines for use on the dish power module is presented in terms of the performance potential of each engine ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... coolants departure nucleate boiling fluid flow fluidic control devices fuel

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The TRIMPWR code has been developed as a post processor for TRIMHX (transient 3D diffusion code) in support of the reactor limits program. TRIMPWR is designed to produce JOSHUA files containing: core power as a function of time, assembly power by hex as a function of time, assembly power post peaking as a function of time, and axial power shapes for each assembly as a function of time (formatted for use by the FLOWTRAN code) from the output of a TRIMHX run. In an attempt to simplify the reactor limits process by reducing the number of assemblies which must be run through FLOWTRAN, TRIMPWR also sorts the assemblies by the product of the power post peaking and the maximum normalized axial power density for each assembly. This follows from the assumption that those assemblies having the maximum value of this product will have the most ...

International Nuclear Information System (INIS)

This thesis was carried out at Forsmark Nuclear Power Plant. The power plant in Forsmark consists of three boiling water reactors (BWR) which produce about 17% of Swedish electricity. In a BWR the nuclear reactions are used to boil water inside the reactor vessel. The water works both as a coolant and as a moderator and the resulting steam is used directly to run the turbines. A problem when running a BWR at low flow conditions is the density wave oscillations that might occur to the water flow inside the fuel assemblies. These oscillations arise due to the connection between power and flow rate in a heated channel with two-phase flow. In order to improve the stability performance of the channel an orifice plate is placed at the inlet of each fuel assembly. Today these orifice plates have sharp edges and a constant resistance coefficient. Experimental work has been done with progressive orifices, the edge of which is half-oval in shape. The ...

Energy Technology Data Exchange (ETDEWEB)

A portable X-ray image system is described comprising: (a) a base assembly including panels and hinges joining the panels together along edges, and compression stops for biasing the hinges to compensate for the weight of payload when mounted on the base assembly, the compression stops being located for interaction with the hinges for biasing the panels to exhibit upward bowing when laid upon a flat surface prior to loading, and to provide resiliency for facilitating the base assembly assuming a substantially flat configuration when a predetermined payload is placed upon the base assembly; (b) an X-ray member; (c) apparatus for detachably mounting a table member to the base assembly to hold the table member at a location above the base; (d) an X-ray source; (e) means for sensing X-rays to form an image; (f) means for mounting the X-ray source and the X-ray sensing means on opposite ...

International Nuclear Information System (INIS)

Natural cooling conditions of the nuclear fuel in the channel type reactor after its shut down are commonly determined with relatively high uncertainty. This is not only to he lack of adequate measurements of thermal parameters i.e. the residual power generation, the coolant flow and temperatures, but also due to indeterminate model of convection mechanism. The numerical simulation of natural convection in multitube fuel assembly in the fuel channel leads to various convection modes including evidently chaotic behaviour. To determine the real cooling conditions in the MARIA research reactor a series of experiments has been performed with fuel assembly equipped with a set of thermocouples. After some forced cooling period (the shortest was half an hour after the reactor shut down) the reactor was left with the only natural convection. Two completely different cooling modes have been observed. The MARIA core consists of ...

Energy Technology Data Exchange (ETDEWEB)

Finite element method is one of the bases for numerical solutions to engineering problems. Complex engineering problems using finite element analysis typically imply excessively large computational time. Parallel supercomputers have the potential for significantly increasing calculation speeds in order to meet these computational requirements. This paper predicts parallel NIKE3D performance on the Kendall Square Research (KSR1) system. The first part of the prediction is based on the implementation of parallel Cholesky (U{sup T}DU) matrix decomposition algorithm through actual computations on the KSRI multiprocessor system, with 64 processors, at Oak Ridge National Laboratory. The other predictions are based on actual computations for parallel element matrix generation, parallel global stiffness matrix assembly, and parallel forward/backward substitution on the BBN TC2000 multiprocessor system at Lawrence Livermore National Laboratory. The ...

Energy Technology Data Exchange (ETDEWEB)

A versatile, high brightness, volume type, low power RF source, capable of producing positive ion beams with intensities as high as 1 mA from gaseous feed materials and microamperes of negative ion beams has been characterized. The source can also be operated as a plasma sputter negative ion source to generate up to 1 mA of a selected species. The performance of the source in the positive and negative volume modes of operation can be greatly enhanced by addition of a removable, water cooled filament assembly in place of the negative sputter probe. For examine, the material utilization efficiencies of gaseous feed species can be more than doubled, total current intensities increased up to 40%, molecular dissociation fractions increased by 20% and minimum operating pressures reduced by a factor of four when operated in the volume mode. These added electrons also favorably effect, as a consequence of lower pressures, the emittance apparently ...

Energy Technology Data Exchange (ETDEWEB)

This report describes development of an electronic system designed to reduce vibration generated by a cryocooler. The diminished vibration makes it practical to use the active cooler to extract heat from a portable gamma ray detector instrument. The system was developed for a Sunpower cryocooler with an integrated counterbalance mass. The overall momentum cancellation approach is also applicable to other similar cryocoolers. The cancellation system is an assembly of several components tailored to accomplish the required vibration reduction with minimum power consumption and volume. It is designed to be powered by a 18--32 Volt battery. Up to ten harmonics of the 58.65 Hz drive frequency are controlled. In addition to the vibration cancellation, the electronic system produces the drive signal for the cryocooler and regulates the cooler temperature. The system employs a sinusoidal drive to reduce the amount of higher harmonic vibration. A digital ...

Energy Technology Data Exchange (ETDEWEB)

A sensitivity study has been done to determine the composition of DUPIC fuel from the viewpoint of neutronics fuel design. The spent PWR fuel compositions were generated and fissile contents adjusted by blending fresh uranium after mixing two spent PWR fuel assemblies. The {sup 239}Pu and {sup 235}U enrichments of DUPIC fuel were adjusted by controlling the amount of fresh uranium feed and the ratio of slightly enriched and depleted uranium in the feed uranium. Based on the material balance calculation, it is recommended that DUPIC fuel composition be such that spent PWR fuel utilization is more than 90%. A sensitivity study on the temperature reactivity coefficient of DUPIC fuel and shown that it is desirable to increase the {sup 239}Pu and {sup 235}U contents to reduce both the fuel and coolant temperature coefficients. On the other hand, refueling simulations of the DUPIC core have shown that the channel power peaking factor, which is a ...

UK PubMed Central (United Kingdom)

Different models have been proposed that link the tubulin heterodimer nucleotide content and the role of GTP hydrolysis with microtubule assembly and dynamics. Here we compare the thermodynamics of...Full Text Available

UK PubMed Central (United Kingdom)

Bipolar spindles assemble in the absence of centrosomes in the oocytes of many species. In Drosophila melanogaster oocytes, the chromosomes have been proposed to initiate spindle assembly...Full Text Available

UK PubMed Central (United Kingdom)

The spliced alignment of expressed sequence data to genomic sequence has proven a key tool in the comprehensive annotation of genes in eukaryotic genomes. A novel algorithm was developed to assemble...Full Text Available

International Science & Technology Center (ISTC)

Safe Transference of Spent Fuel Assemblies from Near-Reactor Storage Pools to Long-term "Dry" Storage

Science.gov (United States)

end of the barrel. The petal valve and ring seal are inserted behind it, and the gun barrel assembly and HP section are clamped together with hydraulic collars. ...

Energy Technology Data Exchange (ETDEWEB)

A lock out assembly for a circuit breaker which consists of a generally step-shaped unitary base with an aperture in the small portion of the step-shaped base and a roughly S shaped retaining pin which loops through the large portion of the step-shaped base. The lock out assembly is adapted to fit over a circuit breaker with the handle switch projecting through the aperture, and the retaining pin projecting into an opening of the handle switch, preventing removal.

Energy Technology Data Exchange (ETDEWEB)

This study presents results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to detect partial defects in Pressurized Water Reactor (PWR) spent fuel assemblies (SFAs). The methodology uses a combination of measured neutron and gamma fields inside a spent fuel assembly in an in-situ condition where no movement of the fuel assembly is required. Previous studies performed on single isolated assemblies resulted in a unique base signature that would change when some of the fuel in the assembly is replaced with dummy fuel. These studies indicate that this signature is still valid in the in-situ condition enhancing the prospect of building a practical tool, Partial Defect Detector (PDET), which can be used in the field for partial defect detection.

Energy Technology Data Exchange (ETDEWEB)

On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a low order nonlinear ...

International Nuclear Information System (INIS)

Short communication.

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop in-reactor assembly (CLIRA), and other special fuel ...

International Nuclear Information System (INIS)

In this work, a feasible and simple method of assembling a micro MEMS-based ?PEMFC (about 0.35 ml in volume and 0.65 g in weight) with the help of a spiral micrometer was proposed. The micrometer provided a constant pressure between the two flow field plates and MEA in assembling for a short term while a special epoxy resin was applied to seal the cell and provide long term pressure between the above components after removing the micrometer. Tests showed that the as-assembled cell had a reasonable performance, which was proved by the linear polarization and EIS experiments. The long term behavior of the ?PEMFC was stable in general except for some fluctuation along time. We concluded that this fluctuation was due to a combined effect of heat produced and water management, which the as-assembled ?PEMFC has its own ability to adjust. More importantly, this experiment demonstrated the full feasibility and ...

British Library Electronic Table of Contents (United Kingdom)

An amphiphilic azobenzene diblock copolymer {2-[4-(4-methoxy phenyl azo)phenoxy]hexyl acrylate co-acrylic acid} was synthesized via reversible addition-fragmentation chain transfer polymerization in a hydrothermal reactor. The products were characterized by 1H-NMR, DSC, GPC and UV-Vis spectroscopy. Different self-assembly behaviors of this amphiphilic diblock copolymer in different organic solvent with different water content were investigated. In THF/H2O solution, the diblock copolymer self-assembled into spheres and the spheres would then change to vesicles with smaller size by increasing the volume of H2O. However, in DMSO/H2O solution, the sizes and morphologies of the self-assembled spheres would not change significantly with an enhanced amount of H2O. Photochromic behaviors of the am...

Science.gov (United States)

The hydraulic characteristics of flow control multiorifice plate assemblies designed for the FFTF reactor were investigated. The pressure drop flowrate characteristics determined in the test are presented. (JWR)

UK PubMed Central (United Kingdom)

The tetrapeptide KDEL is commonly found at the C terminus of soluble proteins of the endoplasmic reticulum (ER), and it contributes to their localization by interacting with a receptor that recycles...Full Text Available

Science.gov (United States)

... non- emissive guidance and collision alert, automated transport in dynamic environments, and assembly and inspection. Foveal Vision, Autonomous Agents, ...

Science.gov (United States)

Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Ultra High Vacuum (UHV) test setup for electron gun testing has been developed. The development of next generation light sources and accelerators require development of klystron as a radio frequency power source, and in turn electron gun. This UHV electron gun test setup can be used to test the electron guns ranging from high average current, quasi-continuous wave to high peak current, single pulse etc. An electron gun has been designed, fabricated, assembled and tested for insulation up to 80 kV under the programme to develop high power klystron for future accelerators. Further testing includes the electron emission parameters characterization of the cathode, as it determines the development of a reliable and efficient electron gun with high electron emission current and high life time as well. This needs a clean ultra high vacuum to study these parameters particularly at high emission current. The cathode emission current, work function and ...

International Nuclear Information System (INIS)

Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume ...

International Nuclear Information System (INIS)

This paper describes Automatic Refueling Planning System (ARPS) for a nuclear power station using Genetic Algorithms (GA) and a Simulated Annealing (SA). ARPS has been developed and verified by applying to the Fugen nuclear power station (NPS), which is a 165MWe, heavy water-moderated, boiling light water-cooled, pressure tube-type reactor developed by JNC utilizing mainly uranium and plutonium mixed oxide (MOX) fuel. Fuel loading patterns have been managed independently in the Fugen NPS since the initial core. A planning of an adequate fuel loading pattern on each operational cycle needs one to two months even for expert core management engineers, for the reason that it has multi-objective optimization and nonlinear problems. In order to achieve the optimum fuel loading pattern and a fuel cost reduction, ARPS has been developed by JNC and CRC Solutions Corporation for the last five years. ARPS firstly generates several thousand fuel loading patterns with GA at ...

Energy Technology Data Exchange (ETDEWEB)

Acanthamoeba castellanii myosins IA and IB demonstrate the catalytic properties of a myosin and can support analogues of contractile and motile activity in vitro, but their single, low molecular weight heavy chains, roughly globular shapes, and inabilities to self-assemble into filaments make them structurally atypical myosins. The authors present the complete amino acid sequence of the 128-kDa myosin IB heavy chain, which they deduced from the nucleotide sequence of the gene and which reveals that the polypeptide is a fusion of myosin-like and non-myosin-like sequences. Specifically, the amino-terminal approx. 76 kDa of amino acid sequence is highly similar to the globular head sequences of conventional myosins. By contrast, the remaining approx. 51 kDa of sequence shows no similarity to any portion of conventional myosin sequences, contains regions that are rich in glycine, proline, and alanine residues, and lacks the distinctive sequence characteristics of an ...

International Nuclear Information System (INIS)

Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface ...

Energy Technology Data Exchange (ETDEWEB)

The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the ...

Energy Technology Data Exchange (ETDEWEB)

The use of computer vision to detect, measure, and perhaps guide the assembly of man-made components is potentially a very significant research and development area. The efficacy of these techniques for any given application depends on both technical and economic considerations. This paper will explore both these considerations using appropriate generic examples. It is our goal to first present a concise discussion of the present state of many technical and economic factors and then extrapolate these factors into the future for the purpose of guiding further investigations.

International Nuclear Information System (INIS)

A reliable inventory control system was developed at the Fast Flux Test Facility (FFTF) to keep track of the occupancy of 900 refueling facility locations, to compile historical data on the movement of each reactor assembly, and to simulate assembly moves. The simulate capability is valuable because it allows verification of documents before they are issued for use in the plant, and eliminates the possibility of planning illegal or impossible moves. The system is installed on a UNIVAC 1100 computer and is maintained using a data base management system by Sperry Univac called MAPPER.

Science.gov (United States)

The Interim Decay Storage tank (IDS) will be located in a concrete cell in the FFTF reactor building. The tank will have capacity to store 112 driver fuel assemblies and 10 test assemblies in sodium. A criticality safety analysis for the design of the IDS tank was performed. From the analysis, it is concluded that under normal operating conditions and minor abnormal conditions that might shift the fuel, the IDS tank will remain adequately subcritical. (auth)

Science.gov (United States)

Amphiphilic pincer palladium complexes bearing hydrophilic and hydrophobic side chains on the planar NCN palladium pincer backbone were designed and prepared via the ligand introduction route. The complexes self-assembled under aqueous conditions to form vesicles with bilayer membranes containing palladium species. The catalytic activity of the vesicles in the Miyaura-Michael reaction in water was investigated. PMID:21837316

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

An improved lockout assembly for locking a circuit breaker in a selected off or on position is provided. The lockout assembly includes a lock block and a lock pin. The lock block has a hollow interior which fits over the free end of a switch handle of the circuit breaker. The lock block includes at least one hole that is placed in registration with a hole in the free end of the switch handle. A lock tab on the lock block serves to align and register the respective holes on the lock block and switch handle. A lock pin is inserted through the registered holes and serves to connect the lock block to the switch handle. Once the lock block and the switch handle are connected, the position of the switch handle is prevented from being changed by the lock tab bumping up against a stationary housing portion of the circuit breaker. When the lock pin installed, an apertured-end portion of the lock pin is in registration with another hole on the lock ...

Energy Technology Data Exchange (ETDEWEB)

Research at the interface between biomolecules and inorganic nanocrystals has resulted in a great number of new discoveries. In part this arises from the synergistic duality of the system: biomolecules may act as self-assembly agents for organizing inorganic nanocrystals into functional materials; alternatively, nanocrystals may act as microscopic or spectroscopic labels for elucidating the behavior of complex biomolecular systems. However, success in either of these functions relies heavily uponthe ability to control the conjugation and assembly processes.In the work presented here, we first design a branched DNA scaffold which allows hybridization of DNA-nanocrystal monoconjugates to form discrete assemblies. Importantly, the asymmetry of the branched scaffold allows the formation of asymmetric2assemblies of nanocrystals. In the context of a self-assembled device, this can be ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

An emergency shutdown system for high-temperature gas-cooled pebble-bed reactors is proposed in addition to the common absorber rod shutdown system. This system is based on the strongly absorbing effect of small boronated graphite spheres (called KLAK), which trickle in case of emergency by gravity from the top reflector into the reactor core. The inner reflector of the Siemens-Argonaut reactor was substituted by an assembly of spherical Arbeitsgemeinschaft Versuchsreaktor fuel elements, and the shutdown effect was examined by installing well-defined KLAK nests inside this assembly. The purpose was to develop and prove a calculational procedure for determining criticality values for assemblies of large fuel spheres and small absorbing spheres.

Energy Technology Data Exchange (ETDEWEB)

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140 nm wide by 100 nm high SiO{sub 2} strip is shown to guide the assembly of 500 nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.

British Library Electronic Table of Contents (United Kingdom)

We have succeeded in aligning self-assembled structures by using a lithographically defined stripe. The 140nm wide by 100nm high SiO2 strip is shown to guide the assembly of 500nm latex spheres so that spheres are aligned along the strip and are in registration on either side of the strip. This method can be used to increase long-range ordering in magnetic storage systems without compromising the density. Inverse sphere Ni arrays were made by electrodeposition through the latex template. We also show that the hexagonal symmetry of the resulting inverse sphere Ni arrays can be simulated using the approach presented below.

International Nuclear Information System (INIS)

The report presents the results of experimental studies conducted to provide a description of the conditions which lead to the occurrence of critical heat flux (CHF), in Combustion Engineering (C-E) fuel assemblies using the C-E standard spacer grid. A CHF correlation is presented which is based on CHF data obtained in tests with electrically heated rod bundles representative of the C-E 14 x 14 and 16 x 16 array fuel assemblies. The results reported are for a uniform axial heat flux distribution. The experiments were conducted in the Medium Pressure Heat Transfer Flow Loop at the Chemical Engineering Research Laboratories at Columbia University.

CERN Document Server

Proteinaceous aggregation occurs through self-assembly-- a process not entirely understood. In a recent article [1], an analytical theory for amyloid fibril growth via secondary rather than primary nucleation was presented. Remarkably, with only a single kinetic parameter, the authors were able to unify growth characteristics for a variety of experimental data. In essence, they seem to have uncovered the underlying allometric laws governing the evolution of filament elongation simply from two coupled non-linear ordinary differential equations (ODEs) stemming from a master equation. While this work adds significantly to our understanding of filament self-assembly, it required an approximate analytical solution representation. Here, we show that the same results are found by purely numerical means once a straightforward and reliable numerical solution to the set of ODEs has been established.

International Nuclear Information System (INIS)

The condition of spent nuclear fuel (SNF) in wet storage at ten Soviet-designed research reactors has been assessed in the light of international experience in order to identify any associated safety issues. These reactors use Al-clad UO2-Al or U-Al alloy dispersion fuels of ?20% enrichment that were fabricated in Russia; the reactors have been in operation since 1955-70. Although originally sent for reprocessing, much of the SNF generated over the last 25-30 years has been stored in fuel storage pools (FSPs) of variable water quality. The external condition of wet-stored SNF assemblies from the reactors surveyed varied from significant failure due to galvanic corrosion that was driven by poor water quality, through gradual pitting caused by slightly impure water, to a stable condition of no observable change in the oxidized Al alloy surface of the irradiated fuel. SNF stability in wet storage seems to depend on three factors: Al being the sole ...

CERN Document Server

Next Generation SSH2 Implementation

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

The Neutron Radiography Reactor (NRAD) operated by Argonne National Laboratory is described in this paper. NRAD was designed to allow radiography of highly absorbing reactor fuel assemblies in the vertical position on the routine basis. 7 figs.

UK PubMed Central (United Kingdom)

Assembly of infectious adenovirus particles requires seven functionally redundant elements at the left end of the genome, termed A repeats, that direct packaging of the DNA. Previous studies revealed...Full Text Available

UK PubMed Central (United Kingdom)

An inexpensive, extremely rapid manual method for simultaneous synthesis of large numbers of oligodeoxyribonucleotides on 50 or 150 nanomole scale is described. The oligonucleotides are assembled in...Full Text Available

UK PubMed Central (United Kingdom)

In Chlamydomonas reinhardtii y-1, newly synthesized chlorophyll a/b-binding apoproteins are degraded when chlorophylls are not present for assembly of stable light-harvesting...Full Text Available

UK PubMed Central (United Kingdom)

The analysis of individual molecules is evolving into an important tool for biological research, and presents conceptually new ways of approaching experimental design strategies. However, more...Full Text Available

UK PubMed Central (United Kingdom)

Various hypotheses have been proposed to explain the molecule processes of sarcomere assembly, partially due to the lack of systematic genetic studies of sarcomeric genes in an in vivo...Full Text Available

UK PubMed Central (United Kingdom)

To assemble into functional structures, biopolymers search for global minima through their folding potential energy surfaces to find the native conformation. However, this process can be hindered by...Full Text Available

Science.gov (United States)

the network were assembled of custom 450 volt Aluminum electrolytic capacitors provided by the Mallory Capacitor Company. A comparison between theoretical ...

UK PubMed Central (United Kingdom)

The endoplasmic reticulum (ER) is a continuous membrane system comprising the nuclear envelope, ribosome-studded peripheral sheets and an interconnected network of smooth tubules extending throughout...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The {sup 252}Cf-source-driven frequency analysis method can be used for measuring the subcritical neutron multiplication factor of arrays of LWR fuel and as little as a single PWR fuel assembly. These measurements can be used to verify the criticality safety margins of spent LWR fuel configurations and thus could be a means of obtaining the information to justify burnup credit for spent LWR transportation/storage casks. In addition, the data can be used to validate calculational methods for criticality safety. These measurements provide parameters that have a higher sensitivity to changes in fissile mass than neutron multiplication factor and thus serve as a better test of calculational methods. The analysis have also shown that measurement of the cross power spectral density (CPSD) between detectors on one side of a single fuel assembly and an internal or external {sup 252}Cf source driving the fission chain multiplication process can be used ...

International Nuclear Information System (INIS)

An overview is presented of the FFTF reactor and plant together with descriptions of core components, core internals, core system, primary and secondary control rod system, reactor instrumentation, reactor vessel and closure head, and supporting test programs.

UK PubMed Central (United Kingdom)

The programming of cellular networks to achieve new biological functions depends on the development of genetic tools that link the presence of a molecular signal to gene-regulatory activity. Recently,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A method is described for testing a diverter system on an offshore drilling rig of a type having a marine riser assembly extending to a subsea well, the diverter system having a packer element and at least one port located below the packer element for the passage of drilling fluid flowing upward from the marine riser assembly during drilling. The method consists of connecting a tubular member to the upper end of a packer having an elastomeric expansive seal element; placing the packer in an upper portion of the marine riser assembly below the diverter system and expanding the seal element against the interior of the upper portion; closing the packer element of the diverter system around the tubular member; and finally applying fluid pressure in the space between the packer element of the diverter system and the seal element of the packer to determine if any leakage in the diverter system exists. The patent also describes an ...

UK PubMed Central (United Kingdom)

BackgroundThe rate of emergence of human pathogens is steadily increasing; most of these novel agents originate in wildlife. Bats, remarkably, are the natural reservoirs of many...Full Text Available

UK PubMed Central (United Kingdom)

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with...Full Text Available

UK PubMed Central (United Kingdom)

Functionalizing of single molecules on surfaces has manifested great potential for bottom-up construction of complex devices on a molecular scale. We discuss the growth mechanism for the initial layers...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A novel scheme is proposed to drive a low-power subcritical fuel assembly by means of a long Cylindrical Radially-convergent Inertial Electrostatic Confinement (CRIEC) used as a neutron source. The concept is inherently safe in the sense that the fuel assembly remains subcritical at all times. Previous work has been done for the possible implementation of CRIEC as a subcritical assembly driver for power reactors. However, it has been found that the present technology and stage of development of IEC-based neutron sources can not meet the neutron flux requirements to drive a system as big as a power reactor. Nevertheless, smaller systems, such as research and training reactors, could be successfully driven with levels of neutron flux that seem more reasonable to be achieved in the near future by IEC devices. The need for custom-made expensive nuclear fission fuel, as in the case of the TRIGA reactors, is eliminated, and the ...

Energy Technology Data Exchange (ETDEWEB)

The Partnership for a New Generation of Vehicles (PNGV) program intends to develop new designs for automobiles that will reduce fuel consumption by two thirds but otherwise have price, comfort, safety, and other measures of performance similar to the typical automobile now on the market. PNGV vehicle designs are expected to substitute lightweight materials, such as aluminum, magnesium, carbon-reinforced polymer composites, glass-reinforced polymer composites, and ultra- light steel, for heavier materials such as steel and iron in automobile components. The target mass of a PNGV vehicle is 1,960 pounds, as compared to the average current vehicle that weights 3,240 pounds. Other changes could include the use of different ferrous alloys, engineering changes, or incorporation of advanced ceramic components. Widespread adoption of these vehicle designs would affect materials markets and require concurrent development and adoption of supporting technologies to supply the ...

Energy Technology Data Exchange (ETDEWEB)

FLOWTRAN-TF is a new two-component, two-phase thermal-hydraulics code to capture the detailed assembly behavior associated with loss-of-coolant accident analyses in multichannel assemblies of the SRS reactors. The local interfacial area of the two-phase mixture is computed by summing the interfacial areas contributed by each of three flow regimes. For smooth flow regime transitions, the code uses an interpolation technique in terms of component void fraction for each basic flow regime.

International Nuclear Information System (INIS)

The integrity of helium circulation loop flanged joints has been attracting recent attention as a design problem, in the development of high-temperature facilities incorporating helium loops (e.g., the VRG-50 pilot nuclear facility). Elevated temperatures and pressures, and the radiation environment, impose additional requirements on sealant materials. This applies first and foremost to rubber seals, which have found widespread favor on account of its excellent elasticity, its ability to spontaneously conform to possible changes in the clearance in the seal assembly, and the low compressive stresses developed in the flange joint assembly.

Energy Technology Data Exchange (ETDEWEB)

Fastening systems for parts that endure high vibration shear loads have traditionally been difficult or expensive to produce. This application describes a fastening system with multiple conical surfaces and eccentric offsets. The novel conical fastener system allows parts to be assembled with reduced tolerance controls at interface features while improving alignment precision. The eccentric conical fastening system is particularly well suited for assemblies with high shear loads in high vibration/shock environments, and/or for systems that have extremely precise pointing requirements.

Energy Technology Data Exchange (ETDEWEB)

The approach-to-critical measurements reported were for a plate-type fuel element where the height of the water moderator and side and top reflector were increased. Measurements were also performed with each of the two annuli of the fuel element to verify both the presence of boron in the fuel plates and the proper uranium loading prior to assembly of the two annuli for full submersion measurements. Measurements were also performed with detectors external to the reflector (> 15 cm of water on top, bottom, and side) for the assembled, submerged HFIR fuel element.

Energy Technology Data Exchange (ETDEWEB)

The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was ...

International Nuclear Information System (INIS)

An effort to expand the irradiation mission of the Fast Flux Test Facility (FFTF) beyond testing fuels and materials for the liquid-metal reactor (LMR) program included a study of the feasibility of producing commercial quantities of "6"0Co. The "6"0Co would be produced by neutron capture in assemblies containing an array of natural cobalt pins and hydrogen-bearing moderator pins located at the periphery of the FFTF core. Adding hydrogenous material to the assemblies enhances "6"0Co production by slowing neutrons into energy ranges where the "5"9Co capture cross section is higher. Some of the moderated neutrons leak from the moderated region to adjacent fuel regions, increasing local fission rates. In order to validate calculated fission rates and establish calculational biases and uncertainties, experiments were conducted in the zero-power plutonium reactor (ZPPR) to measure fission rates in fuel regions adjacent to a mock-up of a cobalt ...

International Nuclear Information System (INIS)

Loading pattern optimization (LPO) for a PWR in nuclear power plant contains three parts: fuel assembly location optimization, burnable poison placement optimization, and used fuel assembly orientation optimization. To solve the former two parts, this paper devises an innovative stochastic evolutionary algorithm-Interval Bound Algorithm (IBA), which can optimize fuel assembly location and burnable poison placement together. IBA just uses the fuel assembly's infinite multiplication factor to get rid of unfavorable patterns and to explore new promising solution space. To solve the last part, this paper applies Estimation of Distribution Algorithms (EDAs), which also belong to evolutionary algorithms. These three parts depend on each other, so it is better not to solve them separately. In order to optimize these parts in a coupled way, we use Symbiotic Co-evolutionary Algorithm (SCA) to incorporate IBA and ...

CSIR Research Space (South Africa)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

This patent describes an ignition system of an internal combustion engine which consists of: a permanent magnet supported by a rotary member of the engine adapted to rotate in synchronism with a rotary shaft of the engine; a generating coil for generating an electromotive force to produce an electric current as the permanent magnet acts on the generating coil during the rotation of the rotary member; an ignition capacitor charged by the electric current generated by the generating coil; a thyristor caused to turn on by a counter electromotive force generated by the generating coil to thereby cause the ignition capacitor to begin to discharge; and an ignition coil generating a high voltage as the ignition capacitor begins to discharge, to cause a spark discharge to take place in an ignition plug of the internal combustion ...

Energy Technology Data Exchange (ETDEWEB)

When completed, Lawrence Livermore National Laboratory's (LLNL) National Ignition Facility (NIF) will be the world's largest laser with experimental capabilities applicable to stockpile stewardship, energy research, science and astrophysics. As construction of the conventional facilities nears completion, operations supporting the installation of specialized laser equipment have come online. Playing a critical role in the precision cleaning of mechanical parts from the NIF beamline are three pieces of aqueous cleaning equipment. Housed in the Optics Assembly Building (OAB), adjacent to NIF's laser bay, are the large mechanical parts gross cleaner (LMPGC), the large mechanical parts precision cleaner (LMPPC), and the small mechanical parts gross and precision cleaner (SMPGPC). These aqueous units, designed and built by Sonic Systems, Inc., of Newtown, Pennsylvania, not only accommodate parts that vary greatly in size, weight, geometry, ...

Energy Technology Data Exchange (ETDEWEB)

Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using copper(II) phthalocyanine ...

Energy Technology Data Exchange (ETDEWEB)

In order to design the microstructure of ceramics with desired dielectric property, an estimation method of dielectric constant of ceramics taking into account the characteristics of microstructure of the ceramics is proposed. In the estimation model, the microstructure of ceramics is represented by the assembly of unit cells comprising of grain, pore and grain boundary. The sizes of grain and pore and the thickness of grain boundary in each unit cell were determined exactly according to their size and thickness distributions in a real ceramic. The dielectric constant of the assembly can be calculated on the basis of equivalent circuit theory. The estimated values of dielectric constant of ceramic BaTiO{sub 3} using the proposed estimation method agree well with experimental ones. The dependence of characteristics of microstructure on the dielectric constant was clarified by the estimation of dielectric constants for the ...

Science.gov (United States)

The theory of a method of determination of reactivity from power spectral density measurements with /sup 252/Cf and the results of experiments with a critical assembly mockup of a liquid-metal fast breeder reactor (LMFBR) and with uranium (93.2 wt % /sup 235/U) metal cylinders and a sphere are presented. This method of reactivity determination has an advantage over existing methods in that it determines the reactivity only from properties of the reactor at the subcritical state of interest and thus does not require a calibration near delayed criticality. In these experiments, the reactivity was varied by changing the fissile loading or the amount of neutron absorber inserted; for the LMFBR mockup, the reactivity varied to approximately 75 dollars subcritical, and for the uranium metal assemblies to approximately 30 dollars subcritical. These experiments verified for the first time the predictions of theory that could be tested in the ...

Science.gov (United States)

Besides the multifunctionality, another equally important aspect of nanoparticles is their engineerability to control the geometrical and chemical properties during fabrication. In this work, we exploited this aspect to define asymmetric surface chemistry of an iron oxide nanosphere by controlling the topology of ligand expression on its surface resulting in a particle with two faces, one displaying only amines and the other only thiols. Specifically, amine-functionalized iron oxide nanospheres were attached on a solid support via a crosslinker containing a disulfide bridge. Liberation of the nanosphere using thiolytic cleavage created thiols on the portion of the particle's surface that interacted with the solid support. Employing a solid-phase strategy and a step-by-step addition of particles, the two unique faces on the same nanosphere served as fittings to assemble them into linear nano-chains. Assembly of chains with various lengths and ...

Energy Technology Data Exchange (ETDEWEB)

Thermal-fluid flow analysis and demonstration test were performed for a spent fuel storage system. The commercial computational fluid dynamics (CFD) code, FLUENT was used for the numerical analysis. Effective thermal conductivities of a spent fuel assembly and a fuel basket were derived to optimize a thermal analysis model. Also, a porous model, which can simplify a complex configuration of a fuel assembly, was used in the thermal analysis. Demonstration test were performed to verify the thermal analysis method and procedure using a half scaled-down model and an electrically heated dummy fuel. The numerical analysis results were compared with the experimental data. Thermal analyses of the storage system were carried out for normal and off-normal conditions by using the verified analysis method.

International Nuclear Information System (INIS)

Rapid self-aggregation of Ni nanodots on Si substrate covered with a thin SiO_2 buffered layer is investigated. The Ni nanodots can hardly self-aggregate on highly heat-dissipated Si substrate with a thermal conductivity of 148 W/m K. Adding a 200-A-thick SiO_2 buffer with an ultralow thermal conductivity of 1.35 W/m K prevents the formation of NiSi_2 compounds, enhances the heat accumulation, and releases the adhesion at Ni/Si interface, which greatly accelerates the self-assembly of Ni nanodots. Dense Ni nanodots with size and density of 30 nm and 7x10"1"0 cm"-"2, respectively, can be formatted after rapid thermal annealing at 850 deg. C for 22 s.

Energy Technology Data Exchange (ETDEWEB)

Analyses of pressure vessel damage resulting from neutron irradiation have primarily relied on two-dimensional transport calculations and a spatial-synthesis methodology to accommodate three-dimensional effects in the results of two two-dimensional calculations. In this paper, the authors report on calculations made on the Pool Critical Assembly (PCA) Benchmark, Configuration 12/13, using the three-dimensional, continuous energy Monte Carlo transport code, MCNP, and the three-dimensional, multigroup, diffusion accelerated discrete ordinates transport code THREEDANT. Neutron fluxes and activation rates as determined from these two calculations are compared to each other and to experimental results in the literature. The authors also draw some conclusions on the value of 3D calculations on the interpretation of experimental results.

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.

International Nuclear Information System (INIS)

We described the use of silica nanoparticles as building blocks for the immobilization of electrogenerated chemiluminescence (ECL) reagent Ru(bpy)_3"2"+ and the fabrication of layer-by-layer assembly film by alternating the deposition of the Ru(bpy)_3"2"+-doped silica nanoparticles and Au nanoparticles. UV-vis absorption spectroscopy, scanning electron microscopy (SEM), cyclic voltammetry and ECL were used to characterize the uniform growth of the multilayer film. Since Ru(bpy)_3"2"+ could still maintain its ECL property when doped into the silica nanoparticles, the as-prepared multilayer film could be used as an effective ECL sensor, and the sensor showed high sensitivity and good stability.

International Nuclear Information System (INIS)

A major new initiative to develop and irradiate a long-lived, mixed-oxide (MOX) fuel system in the Fast Flux Test Facility (FFTF) has been implemented by Westinghouse Hanford Company for the U.S. Department of Energy. The purpose of this new fuel system, called the core demonstration experiment (CDE), is to demonstrate the capability of achieving a 3-yr life in a prototypical, heterogeneous reactor environment under prototypical power and temperature conditions. Ten fuel and six blanket CDEs are establishing the performance characteristics of entire fuel assemblies of wire-wrapped, large-diameter, annular-pellet, advanced MOX fuel pins with the tempered martensitic HT-9 alloy cladding and end caps, HT-9 wire wrap, and an HT-9 duct in a heterogeneous array with the blanket assemblies. The CDE performance characteristics are confirming the basis for design, fabrication, and irradiation of the CDE.

Energy Technology Data Exchange (ETDEWEB)

A study has been conducted on the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. Studies were conducted on three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

International Nuclear Information System (INIS)

Electrical penetration assemblies mounted on the containment wall are used to carry electrical power and signals from the equipment inside this containment (e.g. recirculation pumps, control rod position indications etc.) Todays BWR nuclear power plants apply epoxy resin sealed electric penetration. Contrariwise, the epoxy resin (organic sealant) was replaced with sodium barium glass (inorganic) by way of trial in search for a quality sealant. The glass sealant has been proved to have high temperature airtightness at 300 degC above from an evaluation test involving full-scale model parts. Environmental tests were conducted continuously as to heat cycle, vibration and LOCA etc. the specimens (module) of five types. They were made certain of conformity to the design requirements for boiling water operation. (author).

Energy Technology Data Exchange (ETDEWEB)

We demonstrate control and improvement of charge injection in organic electronic devices by utilizing self-assembled monolayers (SAMs) to manipulate the Schottky energy barrier between a metal electrode and the organic electronic material. Hole injection from Cu electrodes into the electroluminescent conjugated polymer poly[2-methoxy,5-(2{sup {prime}}-ethyl-hexyloxy)-1,4-phenylene vinylene] was varied by using two conjugated-thiol based SAMs. The chemically modified electrodes were incorporated in organic diode structures and changes in the metal/polymer Schottky energy barriers and current{endash}voltage characteristics were measured. Decreasing (increasing) the Schottky energy barrier improves (degrades) charge injection into the polymer. {copyright} {ital 1997 American Institute of Physics.}

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a 400 MW(th) sodium cooled reactor and is the largest test reactor of its type in the world. It was designed and is being operated to serve two purposes: gaining liquid metal system experience and serving as a test bed for fuels and materials. During test operations it is possible that cladding breaches and escape of fission gas to the reactor cover gas region can occur. To identify the source of such a leak all 78 fuel pin assemblies contain ''gas tag'' with a unique ''tag'' mixture in each assembly. The mass spectrometric identification of tag isotope ratios makes possible rapid location and thus faster removal (if required) of breached test pins.

International Nuclear Information System (INIS)

A rapid combustion unit (Baird and Tatlock) incorporating a combustion chamber provided with baffle plates for complete combustion of the sample without the use of a catalyst has been assembled in a glove box for the determination of carbon and hydrogen in actinide complexes. The unit has been modified employing a movable electric furnace and a proportional temperature controller, for decomposition of the sample at desired heating rates. The set-up was standardised employing various reference materials such as benzoic acid, acetanilide, sulphanilamide and 1-chloro 2:4 dinitrobenzene and the standard deviation in the measurements evaluated. It has also been used successfully for the determination of carbon in uranium carbide and carbon and hydrogen in some uranyl-#beta#-diketone-amine N-oxide complexes and in plutonium(IV) oxalate. (auth.).

Science.gov (United States)

ABS>A horizontal steam generator design for the SM-2 was lysis to determine the per formance of such a steam generator under steady state operating conditions and during load transients, The configuration for this design is a two- drum unit consisting of a heat exchanger unit and separator drum interconnected by integral riser and downcomer. An analog computer was used to analyze the steam generator behavior Wring load transients. The effect of various design changes on the response of the steam generator to step chages in load was determined. The horizontal steam generator design was compared to the existing vertical steam generator design for weight, size, price, and performance. (auth)

UK PubMed Central (United Kingdom)

Hepatitis C virus NS3-4A is a membrane-bound enzyme complex that exhibits serine protease, RNA helicase, and RNA-stimulated ATPase activities. This enzyme complex is essential for viral genome replication...Full Text Available

Science.gov (United States)

Lipase catalyzed esterification of therapeutic drugs to functional self-assembled monolayers (SAMs) on 316L stainless steel (SS) after assembly has been demonstrated. SAMs of 16-mercaptohexadecanoic acid (-COOH SAM) and 11-mercapto-1-undecanol (-OH SAM) were formed on 316L SS, and lipase catalysis was used to attach therapeutic drugs, perphenazine and ibuprofen, respectively, on these SAMs. The reaction was carried out in toluene at 60 degrees C for 5 h using Novozyme-435 as the biocatalyst. The FTIR spectra after surface modification of -OH SAMs showed the presence of the C=O stretching bands at 1745 cm(-1), which was absent in the FTIR spectra of -OH SAMs. Similarly, the FTIR spectra after the reaction of the -COOH SAM with perphenazine showed two peaks in the carbonyl region, a peak at 1764 cm(-1), which is the representative peak for the C=O stretching for esters. The second peak at 1681 cm(-1) is assigned to the C=O stretching of the ...

UK PubMed Central (United Kingdom)

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

National Aeronautics and Space Administration (NASA)

The second in a series of flights to assemble the Japanese segment of the International Space Station saw the mammoth Kibo module delivered to the complex complements of Discovery and its crew on the STS-124 mission. Kibo, the Japanese word for u201chopeu201d would house dozens of experiments and serve as a platform for external payloads brought to the complex on subsequent Shuttle flights and the Japanese u201cKounotoriu201d H-2 Transfer Vehicle cargo ship.

CERN Document Server

In this paper, the authors report on the electrical and thermal properties of Bi-2223 composite conductors prepared by the "accordion-folding method" (AFM). Thermal behavior study on AFM Bi-2223 conductors similar to those that have been successfully used to assemble the cold stage of low-loss current leads for CERN, has been performed by using a newly developed experimental apparatus that is described in detail. (7 refs).

Energy Technology Data Exchange (ETDEWEB)

One approach to improving the competitiveness of photovoltaic systems is the development of designs specifically for export applications. In other words, where is it appropriate in a system design to incorporate components manufactured and/or assembled in the receiving country in order to improve the photovoltaic exports from the US? What appears to be needed is a systematic method of evaluating the potential for export from the US of PV systems for various application in different countries. Development of such a method was the goal of this project.

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.

UK PubMed Central (United Kingdom)

In late mitosis and G1, Mcm2-7 are assembled onto replication origins to license them for initiation in the upcoming S phase. After initiation, Mcm2-7 provide helicase activity to unwind DNA at the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This report provides key information on the irradiation environment of the MONJU fuel tests MFA-1 and MFA-2 in the Fast Flux Test Facility (FFTF). This information includes the fission powers, neutron fluxes, sodium temperatures and sodium flow rates in MFA-I, MFA-2 and adjacent assemblies. It also includes MFA-1 and MFA-2 compositions as a function of exposure. The work was performed at the request of Power Reactor and Nuclear Fuels Corporation (PNC) of Japan.

International Nuclear Information System (INIS)

A feature of the Fast Flux Test Facility (FFTF) is that fuel assemblies can be stored within the reactor vessel, either for future use in the core or for temporary storage of spent fuel. Due to the close proximity of fuel assemblies stored in the in-vessel storage (IVS) locations to the ex-vessel flux monitors (EVFMs), neutrons originating in the stored fuel can result in significant contributions to the total EVFM signals. The paper shows EVFM-induced electronic current data during operation at full power for FFTF power cycles 1 through 7. The data were obtained early in each cycle so that signal drift due to core burnup could be ignored. The differences in currents are attributed to differences in cycle-to-cycle core and stored fuel loadings. At the beginning of cycle 1 there were no fuel assemblies stored in IVS. Subsequent to cycle 1, the EVFM currents have been higher than those for cycle 1, by as much as a factor of ...

Energy Technology Data Exchange (ETDEWEB)

The first of three scheduled poolside fuel examinations at the Oyster Creek reactor conducted during February/March 1980, was directed at one of the four symmetrically loaded ENC 8 x 8 lead assemblies that had achieved a burnup of approx. 25,000 MWd/MTU. Forty-five of the fuel rods in assembly UD3-109 were removed and examined. In general, the individual fuel rods were in excellent condition. The average fuel rod diameter continued to decrease during the last cycle was assembly burnup increased from 19,500 to 25,700 MWd/MTU. The creepdown since the beginning of life (BOL) in the center of the fuel rods is about 0.003 in. The fuel rods bore no indication of cladding ridging. Fuel rod growth continued at a linear rate of about 0.02% per GWd/MTU burnup since BOL. Preliminary eddy current test data showed that the cladding was free of significant defects. Visual examination of fuel rods, spacers, and tie plate revealed no ...

Energy Technology Data Exchange (ETDEWEB)

The application of differential optical absorption (DOA) techniques for the in-situ determination of the chemical composition of coal gasification process streams is investigated. Absorption spectra of relevant molecular species and the temperature and pressure effects on DOA-determined spectral characteristics of these species will be determined and cataloged. A system will be configured, assembled, and tested.

Science.gov (United States)

The primary objective of the Air Force Continuous Acquisition and Life-cycle Support (CALS) Test Network (AFCTN) is to evaluate the effectiveness of the CALS standards for technical data interchange and to demonstrate the technical capabilities and operat...

UK PubMed Central (United Kingdom)

Temperature-sensitive mutants defective in 60S ribosomal subunit protein L16 of Saccharomyces cerevisiae were isolated through hydroxylamine mutagenesis of the RPL16B gene and plasmid shuffling. Two...Full Text Available

International Nuclear Information System (INIS)

Design process of steam generator and condenser at Russian nuclear power plant type WWER-1000 is identified. The four chapter of the books are organized as nuclear power plant, types of steam generators specially horizontal steam generator, process of steam generator design and the description of condenser and its process design.

Science.gov (United States)

Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.

UK PubMed Central (United Kingdom)

1. Nitric oxide generation is important in the regulation of resistance vessel tone. Until now, however, there has been no evidence of such a role for basal generation of nitric oxide in the skin microcirculation...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Statistical data on experience gained from operation of steam generators around the world are presented, problems arising in vertical and horizontal steam generators are described, and the conditions of heattransfer tubes used in them are compared.

Science.gov (United States)

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main to...

Energy Technology Data Exchange (ETDEWEB)

The thermal-hydraulic tests for a horizontal steam generator of a next-generation PWR (New PWR-21) were performed. The purpose of these tests is to understand the thermal-hydraulic behavior in the secondary side of horizontal steam generator during the plant normal operation. A test was carried out with cross section slice model simulated the straight tube region. In this paper, the results of the test is reported, and the effect of the horizontal steam generator internals on the thermal-hydraulic behavior of the secondary side and the circulation characteristics of the secondary side are discussed. (author)

Science.gov (United States)

... of waste food generated at McMurdo Station. Some of the difficulties of disposing of waste food ... change waste generation or management at the site? Yes. This will be a temporary waste management ...

Science.gov (United States)

This perspective view of Venus, generated by computer from NASA's Magellan data and color-coded with emissivity, shows part of the lowlands to the north of ...

Energy Technology Data Exchange (ETDEWEB)

This dissertation is devoted to the study of the phenomenological consequences of the three-generation heterotic string models based on the Calabi-Yau compactifications and the N = 2 superconformal constructions.

UK PubMed Central (United Kingdom)

Network generators that capture the Internet's large-scale topology are crucial for the development of efficient routing protocols and modeling Internet traffic. Our ability to design realistic generators...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Short communication

International Nuclear Information System (INIS)

This paper presents a new method and newly developed stabilizing equipment to prevent the loss of synchronism of generators in pumped-storage plants from spreading. The proposed method includes functions to estimate the swing of each generator by using on-line generator output sampled at a rate of 600 times per second after an occurrence of disturbance such as fault, faulty equipment and so on, to predict generator swing 200-300 milliseconds ahead and loss of synchronism between generators in pumped-storage plants and those in thermal and nuclear plants, and to decide the number of generators that must be shed to maintain stability. Tokyo Electric Power Co. (TEPCO) installed the newly developed stabilizing equipment based on this method in the power system in June, 1986.

Energy Technology Data Exchange (ETDEWEB)

Several proposals have been made on the method of calculating generation of formaldehyde released from plywood. In calculating generation per hour of a volatile organic compound of adhesives or coatings using a chamber method, such models are frequently used that the generation is largest when the specimen is exposed in the chamber and that the generation attenuates with lapse of time. In the meantime, a number of studies for calculating formaldehyde generation from construction materials are often those determining a specific quantity of generation in a stationary state, while few studies are the observation of time series variation from immediately after the exposure into the chamber. Accordingly, the subject studies used lauan plywood as the samples and examined the method of calculating the change with lapse of time of the formaldehyde ...

International Nuclear Information System (INIS)

Horizontal steam generators are typical parts of nuclear power plants with pressure water reactor type VVER. By means of this computer program, a detailed thermal-hydraulic study of the horizontal steam generator PGV-1000 has been carried out and a special attention has been paid to the thermal-hydraulics of the secondary side. A set of important steam generator characteristics has been obtained and analyzed. Some of the interesting results of the analysis are presented in the paper. (author)

Science.gov (United States)

Not Available

International Nuclear Information System (INIS)

A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author).

International Nuclear Information System (INIS)

Short communication.

Energy Technology Data Exchange (ETDEWEB)

The presentation deals with the flows on the primary side of a horizontal steam generator under conditions typical to natural circulation cooling of the reactor. The main goal is to analyse the effect of primary flow patterns on the heat transfer capability of the steam generator. Conclusions pertinent to steam generator modelling with system codes are also drawn. (10 refs., 9 figs., 4 tabs.).

International Science & Technology Center (ISTC)

Photochromes for New Generation of Highly Efficient Computers with Three Dimensional (3D) Optical Memory

KoreaScience (Korea)

Full Text Available

Science.gov (United States)

Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Abstract Not Provided

International Nuclear Information System (INIS)

Superconducting generators for high power applications have been of interest for a number of years. Superconducting generators using low temperature superconductors (LTS) have been manufactured to produce up to 20 MW of electrical power and have been configured in either synchronous alternators which have an AC output that may be subsequently rectified to produce DC and homopolar generators which produce low voltage DC. Typically these generators require scrupulous attention to vacuum integrity for cryogenic insulation at 4.2K and tend to be somewhat fragile because of extensive thermal and magnetic shields that are not required in conventional power generators. Recently, high purity aluminum composites have been developed for a high power AC generator that is cooled by cryogenic hydrogen at 21K. This aluminum generator is very compact and ...

International Nuclear Information System (INIS)

... electric utilities electrochemistry energy storage fuel cells organizational models

Energy Technology Data Exchange (ETDEWEB)

This paper deals with dynamic study of co-generator system with derived dynamic models of generator, excitation system, and turbine/governor from field tests. Mainly this study concentrates on frequency control by under-frequency relay. We simulates dynamic study of co-generator system using EMTDC. (author). 4 refs., 13 figs., 4 tabs.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Implementation of a plan to charge waste management costs to the facility that generates such waste requires a long-term commitment and consistent administration. The benefit is that generators are provided the incentive to optimize waste management practices if the charges are appropriately applied. This paper summarizes (1) a plan to charge waste generators, (2) the administrative structure of the plan, (3) a comparison between the rate structure and changes in waste disposal operations, and (4) issues that have surfaced as the plan is implemented. 2 refs., 1 fig., 1 tab.

British Library Electronic Table of Contents (United Kingdom)

Ways of improving the water chemistry used in the turbine generator stator?s cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.

Energy Technology Data Exchange (ETDEWEB)

On March 28, 1979, the Pennsylvania Three Mile Island nuclear power plant Unit 2 (TMI-2) suffered a partial fuel-melt accident. During this accident, over 20,000 lb of molten fuel flowed through holes melted through the baffle plates and through the lower-core support assembly (LCSA). The molten fuel subsequently resolidified in the bottom of the reactor vessel. The lower-core support assembly of the TMI-2 reactor was not structurally damaged during the accident. In order to permit defueling of that region of the core, the LCSA was cut to permit access. A five-axis teleoperator was developed to deliver plasma arc cutting, rotary grinding and abrasive waterjet cutting of end effectors to the LCSA. Complex geometry sectioning was completed in a mock-up facility at chemistry and pressure conditions simulating those of the vessel, prior to actual in-vessel operations. In-vessel activities began in early May 1988 and were completed on April 11, ...

Energy Technology Data Exchange (ETDEWEB)

Inexpensive activated carbon assembly(ACA) was prepared with glass fabrics coated by 10 wt%, 25 wt%, 50 wt% phenolic resin solution, followed by activation at 700{sup o} C under N{sub 2} atmosphere and subsequent surface modification with N{sub 2}, NH{sub 3}, CO{sub 2} gas, respectively. The conversion chemistry of resin to carbon was analyzed by using FT-IR, TGA, SEM, XPS, and the SO{sub 2} adsorption characteristics of the ACA were compared to that of commercial activated carbon fabrics(ACF). The ACA modified by NH{sub 3} showed the best SO{sub 2} adsorption behavior due to the presence of basic functional groups such as amine on the surface, confirmed by XPS. The ACA modified by NH{sub 3} displayed relatively high adsorption capacity of 116.5 mg/g carbon, which is corresponding to 75% adsorption of the commercial ACF(153.4 mg/g) treated with the same method. 14 refs., 6 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

Squeeze film dampers (SFD) are devices utilized to control vibrations of the shafts of high-speed rotating machinery. The SFD - squirrel cage combination is probably the most used system for tuning the stiffness and damping of the supports for rotors installed on ball bearings. Squeeze film dampers are essentially hydrodynamic bearings which contain the ball bearings housings of ball-bearings supported shafts. Consequently, the oil film within the SFD are influenced only by the precession and nutation of the shaft, that is the flow of the oil within the damper is not directly influenced by the spin of the rotor. However, in the classical theory, the flow in the thin film is also governed by the Reynolds equation. In this paper, some of the limits of the classical theory of the SFD are discussed and theoretical and experimental studies, which illustrate the ideas presented herein, are presented as well. The orbits of an unbalanced rotor that is supported by a ...

International Nuclear Information System (INIS)

Proton exchange membrane fuel cells (PEMFCs) are attractive because of their high conversion efficiency, low pollution, lightweight, and high power density. A major area of challenges is the design and engineering of active, robust, and low-cost electrocatalysts. This report discusses recent findings of our investigations of the design and nano-engineering of platinum-vanadium-iron catalysts for use in PEMFC. The membrane electrode assembly was prepared using nano-engineered PtVFe nanoparticles with controlled composition and size supported on carbon as cathode electrocatalysts. The electrocatalytic activity and stability of the catalysts have been characterized by both rotating disk electrode and membrane electrode assembly measurements. The trimetallic catalysts have been shown to exhibit excellent electrocatalytic performance in PEMFC in comparison with commercial platinum catalysts. The results exhibited a good agreement between obtained ...

CERN Document Server

Phase II collimators will complement the existing system to improve the expected high RF impedance and limited efficiency of Phase I jaws. An international collaborative effort has been launched to identify novel advanced materials responding to the very challenging requirements of the new collimators. Complex numerical calculations simulating extreme conditions and experimental tests are in progress. In parallel, an innovative modular design concept of the jaw assembly is being developed to allow fitting in alternative materials, minimizing the thermally induced deformations, withstanding accidents and accepting high radiation doses. Phase II jaw assembly is made up of a molybdenum back-stiffener ensuring high geometrical stability and a modular jaw split in threes sectors. Each sector is equipped with a high-efficiency independent cooling circuit. Beam position monitors (BPM) are embedded in the jaws to fasten setup time and improve beam ...

International Nuclear Information System (INIS)

In a fuel assembly having moderator rods, an axial average value of a ratio between the total of the lateral cross sectional area of a portion to be filled with moderators and the total of the lateral cross sectional area of fuel pellets is determined as greater than 0.4, a lateral cross sectional area of a portion to be filled with moderators per one moderator rod is determined as from 14 to 50cm"2 and the ratio between the total of the lateral cross sectional area of moderators and a total of the lateral cross sectional area of fuel pellets in a horizontal cross section is determined as from 2.7 to 3.4. Since the axial average value for lateral cross sectional area of a portion to be filled with moderators/lateral cross sectional area of fuel pellets is determined as #>=# 0.4, the lateral cross sectional area of moderators of moderator rods is increased, the lateral cross sectional area of a gap water region is decreased to reduce the value of local power ...

Energy Technology Data Exchange (ETDEWEB)

CuAg core-shell nanoparticles are synthesized by ultra-high vacuum thermal evaporation. We show on this system how the Energy-Filtered Transmission Electron Microscopy (EFTEM) technique allows one to improve the characterization by precisely pointing out the formation of core-shell arrangements in bimetallic nanoparticle assemblies. A criterion to measure the shell thickness from EFTEM images on unique core-shell nanoparticles is defined, that can be used for core-shell nanoparticles of any sizes, with shell thicknesses over 1 nm. It is based on the intensity variation along a line drawn across a core-shell nanoparticle on a EFTEM image. This criterion has been validated by a close comparison of the shell thickness measurements performed in this work and the ones obtained by acoustic micro-Raman spectroscopy. Using this criterion, we report a strong correlation between the size of the Cu cores and the formation of the core-shell arrangements in the nanoparticle ...

Energy Technology Data Exchange (ETDEWEB)

The Electromagnetic Fluctuations (EMF) diagnostic will be used to monitor ion fluctuations which could be unstable in MFTF-B. Each probe assembly includes a high impedance electrostatic probe to measure potential fluctuations, and a group of nested, single turn loops to measure magnetic fluctuations in three directions. Eventually, more probes and loops will be added to each probe assembly for making more detailed measurements. The sensors must lie physically close to the plasma edge and are radially positionable. Also, probes at separate axial locations can be positioned to connect along the same magnetic field line. These probes are similar in concept to the rf probes used on TMX, but the high thermal load for 30-second shots on MFTF-B requires a water-cooled design along with temperature monitors. Each signal channel has a bandwidth of .001 to 150 MHz and is monitored by up to four different data channels which obtain amplitude and frequency ...

Energy Technology Data Exchange (ETDEWEB)

Experience at SRS, ORNL, BNL, and Georgia Institute of Technology involving irradiated aluminum clad fuel and target elements, as well as studies of non-irradiated aluminum indicate that some types of aluminum assemblies can be kept in a continually well-deionized water atmosphere for up to 25 years without problems. SRS experience ranges from 2.75 years for the L-1.1 charge kept in deionized D[sub 2]O[sup 1] to greater than 10 years for assemblies stored in the Receiving Basin for Off-site Fuel (RBOF)[sup 2]. Experience at Georgia Institute of Technology reactor in Atlanta yielded the longest value of 25 years without problems. The common denominators in all of the reports is that the water is continually deionized to approximately 2 M[Omega] (2 [times] 10[sup 6]ohms) resistivity and the containers for the water are stainless steel or other non-porous material. This resistivity value is equivalent to a value of 0.5 micromhos or microSiemens ...

Energy Technology Data Exchange (ETDEWEB)

The procedure and operation-by-operation methods of the quality control of structural and fuel materials, mixed fuel pellets of UO/sub 2/-PuO/sub 2/, fuel element cans made of the AISI-316 steel and ready fuel elements are described as well as spacer wires (steel AISI-316), cases of fuel assemblies (FA) and completed FAs. The methods are used in manifacturing fuel elements and FAs for the FFTF reactor. The RDT standards that regulate the structure and functioning of the system of fuel element and FA production management are outlined. Destructive analytical methods characterized by sufficient accuracy but low productivity are noted to represent a considerable share of operations. Some specialized means of nondestructive testing are developed, such as the gauge to measure the total plutonium content in a fuel element, neutron radiography deVice and a laser gauge to measure the FA dimensions. The experience gained served as a basis for designing the equipment and ...

International Nuclear Information System (INIS)

The nanosized luminescent Tb-MCM-41 (1:10) is synthesized by means of sol-gel-assisted self-assembly under basic conditions at room temperature. The results of "2"9Si-MAS NMR and XRD prove that Tb"3"+ doped Si-O framework. The HRTEM image shows that the regular uniform particles with a diameter of 10 nm possess ultralarge pore with diameter 2.0 nm, which is consistent with the result of N_2 adsorption. The BET surface area and porosity of Tb-MCM-41 (1:10) are 1127 m"2/g and 0.84 cm"3/g, respectively. The patterns of selected-area electron diffraction and XRD of Tb-MCM-41 (1:10) show an Fm3m space group in the cubic. FT-IR results show that the peaks near 970 cm"-"1 are assigned to the deformation vibration of silanol group. The as-products are calcined at 800 deg. C and the mesoporous materials possess enormous specific areas and large porosity, it shows that the mesoporous materials are ultrastable.

Energy Technology Data Exchange (ETDEWEB)

A algorithm was developed to determine the characteristic parameters of PWR spent fuel, such as burnup, cooling time and initial enrichment of {sup 235}U by use of gamma-ray activity ratios of {sup 134}Cs/{sup 137}Cs, {sup 154}Eu/{sup 137}Cs and {sup 106}Ru/{sup 137}Cs from the high resolution gamma-ray spectroscopy and ORIGEN-S calculations. For the verification of the method developed, gamma-ray measurements of Kori-1 and Kori-2 nuclear fuel rods were carried out using HPGe gamma ray scanning system. As a results, it is revealed that the measured values are in a good agreement with the operator declared values within the about {+-} 5% errors. Besides, the under-water burnup measuring device has been designed to measure the gamma-ray from the PWR spent fuel assembly. This device will be set up in the pool of Post-Irradiation Examination Facility(PIEF), and used in determination of the average burnup, cooling time and initial enrichment of the PWR spent fuel ...

CERN Document Server

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

Science.gov (United States)

New methodologies for fabrication of multilevel packaging, particularly for RF signal analysis, are investigated. A new method for ``gluing'' silicon wafers together with a Self Assembled Monolayers (SAMs) based nanoglue are discussed, as are methods to enable its use with nonconforming wafers. Results of bond strength measurements as a function of temperature and process will be presented. Surface area bonded is characterized by infrared (IR) imaging. We will also present a method of inducing self-alignment between whole silicon wafers with micrometer precision. This represents a qualitative departure from alignment of millimeter-sized object as has been previously demonstrated. Self-alignment is induced by creating hydrophilic and hydrophobic regions on the wafers and using capillary forces of water in these regions to force the wafers to align with little to no outside influence. Results are characterized by IR imaging. Physical ideas that enable the whole-wafer ...

International Nuclear Information System (INIS)

The paper analyses the advantages and disadvantages of the second generation improved technologies and third generation technologies mainly developed in China in terms of safety and economy. The paper also discusses the maturity of the second generation improved technologies and the sophistication of the third generation technologies respectively. Meanwhile, the paper proposes that the advantage and disadvantage of second generation improved technologies and third generation technologies should be carefully taken into consideration and the relationship between the maturity and sophistication should be properly dealt with in the current stage. A two-step strategy shall be taken as a solution to solve the problem of insufficient capacity of nuclear power, trace and develop the third generation technologies, so as to ensure the sound and fast ...

British Library Electronic Table of Contents (United Kingdom)

The steam generator is a very important component of a nuclear power plant. Historically, vertical steam generators came to be used abroad and horizontal steam generators in our country. Both types of steam generators operate successfully in nuclear power plants and satisfactorily fulfill their functions, enabling the production of electricity. Repeated attempts to re-examine the existing concepts in one or another country have been unsuccessful because there are no convincing arguments for this. Nonetheless, the question of using a different type of steam generator is raised periodically in our country and abroad. This article briefly reviews different concepts of steam generators. Their parameters, characteristics, and thermal efficiency are compared and ways to increase the latter are a...

Science.gov (United States)

In the current wind turbine generation system, there are substantial problems such as the maximum power of the wind turbine cannot be obtained under the fluctuating wind speed, high in cost and low in annual net electricity production (due to mismatch between a generator and a wind turbine). A new wind turbine generator optimized for the wind turbine output is presented in order to solve such problems. This wind turbine generator consists of a permanent magnet generator, a reactor and a rectifier, and uses neither a control circuit which requires standby electricity nor a PWM converter having a switching element. By selecting most appropriate combination of the permanent magnet generator having multiple windings and the reactor connected in series with each winding, the maximum output of the wind turbine can be obtained without using a control circuit. The new ...

Science.gov (United States)

With the help of self-assembly, thermal sintering, selective etching techniques and sol-gel process, the non-close packed (ncp) face-centered cubic (fcc) photonic crystals of titanium dioxide (TiO2) hollow spheres connected by TiO2 cylindrical tubes have been fabricated using silica template. The photonic bandgap calculations indicate that the ncp structure of TiO2 hollow spheres was easier to open the pseudogaps than close packed system at the lowest energy. PMID:17097102

International Nuclear Information System (INIS)

The main activities developed at 'Instituto de Energia Atomica' Sao Paulo, Brazil, on the recovery of uranium from ores, the purification of uranium and thorium raw concentrates and their transformation in nuclear grade compounds, are reviewed. The design and assemble of pilot facilities for ammonium diuranate (ADV) uranium tetrafluoride, uranium trioxide, uranium oxide microspheres, uranyl nitrate denitration, uranim hexafluoride and thorium compounds are discussed. The establishment of analytical procedures are emphasized.

International Nuclear Information System (INIS)

An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation.

Energy Technology Data Exchange (ETDEWEB)

This paper reports progress in the fabrication and characterization of an array of 1nm-scale colloidal particles (i.e., quantum-dot array) that can be operated to execute nontrivial and innovative computations, possibly including quantum logic. We discuss the actual fabrication of 2-nm metal clusters as an example of possible quantum dot implementation. Innovative and unconventional paradigms underlie the different stages of this work. For example, regular array geometry is achieved by directing appropriately derivatized metal clusters to preselected locations along a stretched strand of an engineered DNA sequence.

International Nuclear Information System (INIS)

A method and apparatus for nuclear borehole logging, and in particular, neutron porosity logging, uses a neutron source, and a pair of spaced lithium detectors, preferably Li"6I crystal or Li"6 doped glass, to detect neutrons emitted from a borehole formation being logged. The spectrum developed by the lithium detectors is processed to remove the gamma ray background radiation and the hydrogen absorption peak, thus allowing a more accurate neutron count. A Gaussian curve is fitted to the neutron peak of the spectrum, the curve eliminating the hydrogen absorption peak. The area under this Gaussian curve represents the neutron count. (author).

Energy Technology Data Exchange (ETDEWEB)

Invention relates to woodworking industry and concerns method of cementing of materials of foam plastic with duralumin, glued plywood, etc. Known methods of cementing of materials by effect of electromagnetic field of superhigh frequencies are unproductive and do not make it possible to cement parts on the plane. Target of invention - acceleration of process of cementing of planar, including of complex configuration, parts and assemblies from wood, foam plastic, duralumin, glued plywood and other materials. For this material is cemented under the effect of directed electromagnetic field of superhigh frequency in the range 01-50 GHz, the specific power of 0.5-15 W/cm3.

International Nuclear Information System (INIS)

Effects of the rapid early-in-life expansion of metal fuel were measured in an irradiation experiment in the Fast Flux Test Facility (FFTF). This important performance/design information was obtainable through the unique combination of a dimensionally stable FFTF oxide core and the calibrated proximity instrumentation associated with the test. These results delineate the time dependence of metal-fuel swelling and provide quantitative estimates of the magnitude of axial fuel swelling in full-length metal-fuel assemblies. Final posttest examination results will define actual fuel column growth levels.

Energy Technology Data Exchange (ETDEWEB)

Nanoparticles represent versatile building blocks in material science and nanotechnology. Thereby, the defined assembly of nanostructures (13 and 56 nm in diameter, respectively) is of significant importance. Short DNA sequences can be bound to the nanoparticle surface thus enabling highly specific DNA hybridization-driven events that direct the formation of nanoparticle constructs.In this paper, examples for the defined formation of gold nanoparticle constructs are demonstrated. In addition, gold-silver core-shell nanoparticles are introduced as further building blocks for the hybridization-controlled formation of nanoparticle constructs.

International Nuclear Information System (INIS)

A fiber optic feedthrough module which comprises a metal sleeve, a fiber optic element extending through the sleeve in spaced relation thereto, and a tandem series of centrally-apertured mating annular sealant bodies of thermoplastic material surrounding the fiber optic element and compressed between it and the sleeve. The module is made by first providing a loose subassembly of a plurality of individual but interfitting sealant bodies on the fiber optic element and then inserting this subassembly into a metal sleeve, following by swaging the whole assembly which eliminates clearances and provides sealed interfaces between the various contacting components. (author).

Energy Technology Data Exchange (ETDEWEB)

For the determination of top dead center (TDC) of a running engine a measuring system using microwaves was developed by AEG and Volkswagen AG. The measuring method utilizes the Doppler shift of the microwaves, which were reflected at the up and down moving piston, and the varying resonance properties of the combustion chamber. The system works with a frequency of 61.4 GHz and can be used as well for spark ignition as form compression ignition engines, particularly for direct injection engines. The output signal is symmetrical to TDC. For data acquisition and data processing, i.e. the calculation of the point of symmetry, the computer system FARES is used in a special assembly.

International Nuclear Information System (INIS)

The paper provides a brief description of the fuel characterization for Fast Breeder Test Reactor (FBTR) and Prototype Fast Breeder Reactor (PFBR). The development and characterization of mechanical properties of Alloy D9 clad and wrapper tubes are discussed. The problems associated with fusion welding of Alloy D9 are outlined. Non-destructive characterization of cladding tubes by optimum encircling eddy current probes, on-line and off-line neural network methods is presented. Both the on-line and off-line neural network methods could readily detect and size defects specified by the designers

Energy Technology Data Exchange (ETDEWEB)

This presentation is primarily about unsteady aerodynamics in relation to wind turbines. It is divided into three very distinct sections: (1) Basic unsteady aerodynamics; (2) VAWT performance modelling and (3) Passive stall regulation of VAWTs. The aim of the presentation is to illustrate that, if desired, future wind turbine blades could be aerodynamically tailored to exploit the unsteady nature of the VAWT flow with far greater confidence and insight than has been hitherto possible. To this effect, the collaborating British research teams and, in particular, VAWT Ltd. have assembled sufficient knowledge for such a conclusion to be made. (author).

Energy Technology Data Exchange (ETDEWEB)

The purpose of the invention is to reduce the labor intensity of assembly and disassembly of a drilling rig with a large unit transport method. To achieve the cited goal, in the base of the drilling rig unit, which contains uprights with hinges, installed between the frame and the foundation support, where each of the hinges is linked by a flexible element with the frame, the frame and the foundation support are equipped with encircling elements installed with the capability of interacting with the flexible element, where the uprights are linked with the frame by means of hinges with the capability of locking and the uprights by means of the encircling and flexible elements are connected in pairs.

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

Energy Technology Data Exchange (ETDEWEB)

A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.