Energy Technology Data Exchange (ETDEWEB)

A growth model of pitting corrosion of carbon steel in cooling water systems was developed on microscopic observations of pits and electrochemical studies. Results of pitting corrosion measurements in laboratory and field conditions with the model, using a newly developed electrochemical device, are discussed. For an actual heat exchanger up to a year operation, the values of pitting depth estimated were in good agreement with the measured values.

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Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium ...

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The characteristics of fractures in unit 2 of the Tshirege Member of the Bandelier Tuff were documented in Pit 39, a newly excavated 13.7 m deep disposal pit at Material Disposal Area G on Mesita del Buey. The average spacing between fractures is about 1.0 to 1.3 m, the average fracture aperture is about 3 to 5 mm, and the average fracture dip is about 76o to 77o. Fracture spacing and dip in Pit 39 are generally consistent with that reported from other fracture studies on the Pajarito Plateau, although the fracture apertures in Pit 39 are less than reported elsewhere. Measured fracture orientations are strongly affected by biases imparted by the orientations of the pit walls, which, combined with a small data set, make identification of potential preferred orientations dlfflcult. The most prominent fracture orientations observed in Pit 39, about E-W and N20E, ...

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This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers; (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users ...

CERN Document Server

Process algebra for parallel and distributed processing

International Nuclear Information System (INIS)

This paper deals with the pitting corrosion of evaporators in the liquid - radwaste system of nuclear power stations. Corrosion testrs were conducted by the anodic polalization of specimen in the chloride solution. (1) The initiation of the pitting in SUS 304, SUS 316 stainless steels was inhibited by addition of NaOH and H_3BO_3, however, these addition had no effect on the pitting propagation. (2) Inconel 625 had the resitivity against the pitting initiation superior to that of stainless steels, but this was not necessarily in the case of the pitting propagation. (3) It is noticed for pitting prevention that the environmental and material effect on the pitting initiation differed from that on the pitting propagation. (author).

International Nuclear Information System (INIS)

This document presents a summary of the work performed in support of the Buried Waste Robotics Program Subsurface Mapping Project. The project objective was to demonstrate the feasibility of remotely characterizing buried waste sites. To fulfill this objective, a remotely-operated vehicle, equipped with several sensors, was deployed at the Idaho National Engineering Laboratory. Descriptions of the equipment and areas involved in the project are included in this report. Additionally, this document provides data that was obtained during characterization operations at the Cold Test Pit and the Subsurface Disposal Area, both at the Idaho National Engineering Laboratory's Radioactive Waste Management Complex, and at the Idaho Chemical Processing Plant. The knowledge gained from the experience, that can be applied to the next generation remote-characterization system, is extensive and is presented in this report.

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The use of linear accelerators in radiotherapy is of great importance in Medicine, and according to international recommendations the electron beam dosimetry has to be performed using plane-parallel ionization chambers, previously calibrated in standard gamma radiation fields at accredited laboratories. In this work, calibration methods of plane-parallel ionization chambers used in dosimetry procedures of high energy electron beams of clinical accelerators were presented, tested and intercompared. The experiments were carried out using gamma radiation beams of {sup 60} Co at the Calibration Laboratory of Clinical Dosemeters at IPEN and electron beams od 4 to 16 MeV at the Radiotherapy Department of Hospital Israelita Albert Einstein, Sao Paulo. A method was chosen to be established at IPEN. Proposals of the calibration procedure, calibration certificate and data sheets are presented. (author)

KoreaScience (Korea)

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Pitting corrosion can be considered as a combination of two physical processes: the pit generation process and its depth growth process. Both processes are uncertain and can be modeled by stochastic processes. A model that combines two stochastic processes to describe pitting corrosion was developed. In this model, the pit generation process is represented by the Poisson process, and the pit depth growth process is modeled by the Markov process. The probability distribution of corrosion pit depth and the probability of time-to-failure are derived based upon the combined stochastic processes. Examples of the use of this method in dealing with experimental data also were developed.

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The Alloy 800 tubes used in CANDU 6 steam generators have not experienced significant corrosion damage to date, which may be attributed to successful water chemistry control strategies. However, it is known that Alloy 800, like other steam generator (SG) tubing materials, is not immune to corrosion, especially pitting, under some plausible but off-specification operating scenarios. Electrochemical measurements provide information on corrosion susceptibility and rate, which are known to be a function of water chemistry. Using laboratory data in combination with chemistry monitoring and diagnostic software it is possible to assess the impact of plant operating conditions on SG tube corrosion for plant life management (PLIM). In this context, this paper discusses the results of electrochemical measurements made to elucidate the corrosion behaviour of Alloy 800 SG tubes under conditions simulating those plausible in SG crevices. In addition to ...

Science.gov (United States)

Water transport in conifers occurs through single-celled tracheids that are connected to one another via intertracheid pit membranes. These membranes have two components: the porous margo, which allows water to pass through the membrane, and the impermeable torus, which functions to isolate gas-filled tracheids. During drought, tracheids can become air filled and thus hydraulically dysfunctional, a result of air entering through the pit membrane and nucleating cavitation in the water column. What are the hydraulic tradeoffs associated with cavitation resistance at the pit level, and how do they vary within the structural components of the intertracheid pit? To address these questions, we examined pit structure in 15 species of Cupressaceae exhibiting a broad range of cavitation resistances. Across species, cavitation resistance was most closely correlated to the ratio of the torus ...

Science.gov (United States)

Jul 16, 2001... LAM PIT KEI LI PIT YEUNG PITA COLUMBA MOTHER PITA VERA L ..... PLASENCIA ALEXANDER W PLASENCIA CESAR PLASENCIA ...

Energy Technology Data Exchange (ETDEWEB)

The feasibility of removing petroleum hydrocarbons from oil fields produced waters using biological treatment was evaluated under laboratory and field conditions. Based on previous laboratory studies, a field-scale prototype system was designed and operated over a period of four months. Two different sources of produced waters were tested in this field study under various continuous flow rates ranging from 375 1/D to 1,800 1/D. One source of produced water was an open storage pit; the other, a closed storage tank. The TDS concentrations of these sources exceeded 50,000 mg/l; total n-alkanes exceeded 100 mg/l; total petroleum hydrocarbons exceeded 125 mg/l; and total BTEX exceeded 3 mg/l. Removals of total n-alkanes, total petroleum hydrocarbons, and BTEX remained consistently high over 99%. During these tests, the energy costs averaged $0.20/bbl at 12 bbl/D.

Energy Technology Data Exchange (ETDEWEB)

The effect of open pit mine motor transport with ICE on the air basin is examined using the example of shale mines and open pits of the production association ''Estonslanets''. Efficient areas of use of different types of open pit mine motor transport, diesel-trolley tracks and electric cars are determined based on technical-economic and ecologic feasibility.

International Nuclear Information System (INIS)

Pitting corrosion is a kind of electrolytic corrosion by which the surface of a material is locally affected owing to inhomogeneities on the part of the material or medium. The paper deals briefly with questions relating to the importance, to parameters medium or materialwise, influence on production and construction, as well as the general conditions for pitting corrosion. In particular oxygen corrosion in unalloyed and low-alloy steel, and pitting corrosion in ferritic chromium-steel and austenitic chromium-nickel (molybdenum) steel is described. (DG).

International Nuclear Information System (INIS)

Pitting corrosion of Inconel 600 was examined in chloride and sulfate solutions through usage of potentiodynamic polarization techniques. The effects of chloride and sulfate concentration were investigated in the range of 0.0001 to 0.1 M. Increasing chloride concentrations resulted in active shifts of the pit nucleation potential. Immunity to pitting corrosion was evident at a chloride level below 0.005 M. Increasing sulfate concentrations resulted in improved pitting resistance of Inconel 600 in chloride solutions. Detrimental effects associated with pitting were evident with low-level sulfate being added to dilute chloride media. The density of pits increased with increasing chloride concentrations or temperature between room temperature and 70 C. Systematic trends for the depth of pits were not evident. The observations of ...

International Nuclear Information System (INIS)

A computerized corrosion measuring system (EG and G model 350 A) was used to study the influence of Cr, Mo, Ti, Nb and W on the pitting corrosion of nickel base alloys in 3% NaCl at 90"0C. The electrochemical parameters under investigation are the corrosion potential E_c_o_r_r, pitting potential E_p and protection potential E_p_p. The corrosion behaviour of nickel base alloys were studied by using pitting scan and potentiostatic techniques. Values of corrosion potential, pitting potential and protection potential were used for a ranking of alloys for corrosion resistance.

Energy Technology Data Exchange (ETDEWEB)

The physical properties of polymer blends consisting of one or more crystallizable components are affected by the microstructure of these materials. In particular, the degree of crystallinity can be influenced by processing parameters, and the crystallinity, as well as the phase distribution, may vary as a function of depth through an injection molded part Conventional x-ray diffraction techniques can provide information regarding both phase composition and degree of crystallinity, but, because of the relative transparency of these materials to wavelengths generally available in the laboratory, these techniques provide information representative of only the bulk. By employing parallel beam optics at varying grazing incidence angles, the x-ray sampling depth can be varied without loss of resolution. This technique can be used to vary the effective analysis depth from the top several hundred angstroms for low razing incidence to centimeters for ...

Science.gov (United States)

The series hybrid vehicles were found to be relatively expensive in comparison to the parallel or parallel-flywheel hybrids. ...

Energy Technology Data Exchange (ETDEWEB)

Six safety initiatives have been identified for accelerating the resolution of waste tank safety issues and closure of unreviewed safety questions. Safety Initiative 5 is to reduce safety and environmental risk from tank leaks. Item d of Safety Initiative 5 is to complete corrosion studies of single-shell tanks to determine failure mechanisms and corrosion control options to minimize further degradation by June 1994. This report has been prepared to fulfill Safety Initiative 5, Item d. The corrosion mechanisms that apply to Hanford Site single-shell tanks are stress corrosion cracking, pitting/crevice corrosion, uniform corrosion, hydrogen embrittlement, and microbiologically influenced corrosion. The corrosion data relevant to the single-shell tanks dates back three decades, when results were obtained from in-situ corrosion coupons in a few single-shell tanks. Since that time there have been intertank transfers, evaporation, and chemical alterations of the waste. ...

International Nuclear Information System (INIS)

Research highlights: #-># Welding parameters affect pitting corrosion resistance of AL-6XN laser welds. #-># Lower heat input laser welds correspond to higher critical pitting temperature. #-># Depletion of Mo and Cr at dendrite cores causes preferential pitting corrosion. #-># Local Mo level at dendrite cores dominates weld pitting corrosion susceptibility. #-># Lower heat input laser welds manifest lower degree of microsegregation of Mo. - Abstract: Pitting corrosion resistance of laser welds of AL-6XN superaustenitic stainless steel (SASS) was investigated in acidic chloride ion medium. It was found that the critical pitting temperature (CPT) of the laser welds increased with increasing welding speed or decreasing laser power. Pitting attack preferentially occurred at selective dendrite cores of the laser welds. Analytical ...

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The solubility behavior of solid residues from the heat treatment of domestic rubbish was examined by simulated precipitation in laboratory lysimeters. The precipitation corresponded to the average amount of rain in West Germany and was applied at different time periods. Specific soil characteristics, the value of k/sub f/ and the water retention capacity was determined in this way. In parallel with the lysimeter flood ions, extraction (by batch process) was done, in order to find the maximum solubility of the materials used. It was found that for pyrolysis residues from reactor temperatures of 450/sup 0/ to 1000/sup 0/C, a greater solubility was measured than for slag from combustion. The eluates from these residues gave information about the degree of contamination or on the solubility of the measured parameters and materials in organoleptic, physical, organic and inorganic examinations. The concentrations of harmful substances in the eluates ...

International Nuclear Information System (INIS)

Current light water reactor (LWR) steam generators have been affected by a variety of corrosion and mechanical damage degradation mechanisms. Included are wear caused by tube vibration, intergranular corrosion, pitting, and thinning or wastage of the steam generator tubing and accelerated corrosion of carbon steel supports (denting). The Electric Power Research Institute (EPRI) and the Steam Generator Owners Groups (I, II) have sponsored laboratory and field studies to provide ameliorative actions for the majority of the damage forms experienced to date. Some of the current corrosion mechanisms are aggravated or caused by unique materials choices or materials interactions. New materials have been proposed and at least partially qualified for use in replacement model steam generators, including an advanced LWR design. In so far as possible, the materials choices for the advanced LWR steam generator avoid the corrosion pitfalls seemingly inherent ...

Energy Technology Data Exchange (ETDEWEB)

Pit lakes form when open-pit mining operations are discontinued and dewatering ceases. The increase in open-pit metal mining since the 1970s will lead to the formation of numerous pit lakes over the next 50 years. Many of these lakes will develop acid sulfate conditions with high levels of dissolved metals. Approaches to remediation of these conditions that have been recommended include the addition of lime or other alkaline materials and the stimulation of sulfate-reducing bacteria. However, prevention rather than remediation is probably the preferable approach. Measures to prevent oxidation of mining waste and wall rocks, including measures to fill pits quickly with water, to inhibit the activity of acidophilic sulfur-oxidizing bacteria, and to promote anoxic conditions at the lake bottoms may minimize the formation of acids and dissolved metals. (orig.)

International Nuclear Information System (INIS)

SAFT-UT technology is shown to provide significant enhancements to the inspection of materials used in US nuclear power plants. This report provides guidelines for the implementation of SAFT-UT technology and shows the results from its application. An overview of the development of SAFT-UT is provided so that the reader may become familiar with the technology. Then the basic fundamentals are presented with an extensive list of references. A comprehensive operating procedure, which is used in conjunction with the SAFT-UT field system developed by Pacific Northwest Laboratory (PNL), provides the recipe for both SAFT data acquisition and analysis. The specification for the hardware implementation is provided for the SAFT-UT system along with a description of the subsequent developments and improvements. One development of technical interest is the SAFT real time processor. Performance of the real-time processor is impressive and comparison is made of this dedicated ...

UK PubMed Central (United Kingdom)

The aim of this study was to assess the possibility of digital image analysis of pit-and-fissure discoloration in order to diagnose caries. Digital images showing pit-and-fissure discoloration in 100...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In order to investigate pitting corrosion of copper coiled tubes for air conditioning systems with an open heat storage water tank, the effect of carbon films on the inner surface of copper tubes and fine corrosion-product particles in water as environmental corrosion factor on pitting corrosion was studied by field test under real environmental conditions. As a result, pitting corrosion of copper tubes was caused by synergistic effect of fine corrosion-product particles in water and carbon films. Generation of pitting corrosion was derived from deposition of the films and particles, while considerable growth of pitting corrosion was dependent on the particles. Time variation of spontaneous electrode potential also showed the effect of the film and particle. Pitting corrosion potential was estimated to be nearly 100mV vs. SCE. The following measures against ...

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Pitting corrosion measuring method for almunum alloys sold on the market was studied. By addition of a little quantity of Cu {sup ++} ion, corrosion potential of alminum alloys rapidly approachs to pitting corrosion potential in the solution including chloride. After Cu {sup ++} ion of 5ppm is added in advance into the solution including chrolide to measure the pitting corrosion potential, alminum alloy test pieces are imersed into the solution in the atmospheric air, then the stable corrosion potential is shown after three-minite imersion, and this potential is defined to the pitting corrosion potential. The pitting corrosion potential can be easily measured by this method stated above (copper ion method). The values measured by copper ion method is comparatively agreed with that measured by the existing potentio dynamic method. The pitting corrosion potential ...

International Nuclear Information System (INIS)

Three different techniques for pitting corrosion potential measurement on austenitic stainless steel (Fe18Cr10Ni) were compared: conventional polarization method, a new Avesta electrochemical corrosion measurement cell and a scratch technique. Special attention was paid to the effects of crevice corrosion during pitting corrosion potential measurement and to their elimination. Development of a rapid test technique for reliable pitting corrosion potential determination was aimed at and resulted from comparison of the different techniques.

Energy Technology Data Exchange (ETDEWEB)

Electrochemical cyclic potentiodynamic polarization experiments were performed on several candidate waste package container materials to evaluate their susceptibility to pitting corrosion at 90 degrees C in aqueous environments relevant to the potential underground high-level nuclear waste repository. Results indicate that of all the materials tested, Alloy C-22 and Ti Grade-12 exhibited the maximum corrosion resistance, showing no pitting or observable corrosion in any environment tested. Efforts were also made to study the effect of chloride ion concentration and pH on the measured corrosion potential (Ecorr), critical pitting and protection potential values.

International Nuclear Information System (INIS)

The pitting corrosion resistance of three different types of stainless steel implanted with silicon is investigated using the potentiokinetic polarization technique. The specimens are tested in 3% NaCl and 0.1 N HCl solutions. Silicon ion implantation inhibits pitting corrosion of the steels in both aqueous media. The corrosion resistance depends on the silicon dose. Post implantation annealing only slightly alters the localized corrosion. (author).

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The question about expanding the boundaries of the open pit mining method is examined. The use of methods which consider the advantages of open and underground mining operations with their joint use in horizontal and evenly dipping deposits will make it possible to objectively select the mining method, to expand the range of use of open pit mining operations in the deposits of the Far North and provide an improvement in the technical and economic indicators of mineral extraction.

International Nuclear Information System (INIS)

A newly synthesized glycine derivative (termed GlyD), 2-(4-(dimethylamino)benzylamino)acetic acid hydrochloride, was used to inhibit uniform and pitting corrosion processes of Al in 0.50 M KSCN solutions (pH 6.8) at 25 "oC. For uniform corrosion inhibition study, Tafel extrapolation, linear polarization resistance and impedance methods were used, complemented with SEM examinations. An independent method of chemical analysis, namely ICP-AES (inductively coupled plasma atomic emission spectrometry) was also used to test validity of corrosion rate measured by Tafel extrapolation method. GlyD inhibited uniform corrosion, even at low concentrations, reaching a value of inhibition efficiency up to 97% at a concentration of 5 x 10"-"3 M. Results obtained from the different corrosion evaluation techniques were in good agreement. This new synthesized glycine derivative was also used to control pit nucleation and growth on the pitted ...

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Accumulation of Chloride and Cupric ions under the sludge on the steam generator tubing surface in the area between tube sheet and the first tube support is known to be the main reason for the pitting corrosion. In addition to those ions, oxygen, pH, temperature, heat treatment history, contests of minor elements such as C, S or Ti in the alloy are also influencing the material's the pitting corrosion resistance. a series of autoclave pitting test was conducted to evaluate the pitting corrosion characteristics of the domestically produced alloy 690 tubing material and compare with that of INCO manufactured material. 16 refs., 44 figs., 5 tabs. (Author)

Energy Technology Data Exchange (ETDEWEB)

Firstly, pitting corrosion observed on hold frames in cargo holds of bulk carriers which exclusively carry coal and iron ore has been investigated in detail. It was shown that the shape of the corrosion pits observed on them is a circular cone and the ratio of the diameter to the depth is in the range between 8 to 1 and 10 to 1, which is different from the trend observed for the bottom shell of the oil tanker where the ratio is in the range between 4 to 1 and 6 to 1. Secondly, a series of tensile tests has been conducted to investigate the effect of pitting corrosion on tensile strength of members. It was pointed out that the tensile strength decreases gradually and the total elongation decreases drastically with the increase of the thickness loss due to pitting corrosion. The reduction of the tensile strength of the members with pitting corrosion is larger than that of members with ...

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

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The effects of thiosulfate ion and solution pH on pitting corrosion of Alloy 690 in chloride solution were explored. Potentiodynamic polarization measurements were conducted to evaluate pitting corrosion susceptibility of Alloy 690 in these environments. The results showed that pitting corrosion occurred in the mill-annealed (1050 deg. C/5min) Alloy 690 in 1 wt% NaCl solution but not in 0.1 M Na{sub 2}S{sub 2}O{sub 3} solution. The value of pitting nucleation potential (E{sub np}) determined in 1 wt% NaCl solution (without Na{sub 2}S{sub 2}O{sub 3} ) increased with increasing solution pH value in the range of 2-10. The addition of Na{sub 2}S{sub 2}O{sub 3} to 1 wt% NaCl solution greatly affected the pitting corrosion behavior, which was dependent on concentration. The preformed nickel sulfide surface film due to the presence of Na{sub 2}S{sub 2}O{sub 3} caused Alloy 690 to become ...

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The susceptibility to pitting corrosion of AA2024-T4, AA7075-T651 and AA7475-T761 aluminium alloys was investigated in aqueous neutral chloride solution for the purpose of comparison using electrochemical noise measurement. The experimentally measured electrochemical noises were analysed based upon the combined stochastic theory and shot-noise theory using the Weibull distribution function. From the occurrence of two linear regions on one Weibull probability plot, it was suggested that there existed two stochastic processes of uniform corrosion and pitting corrosion; pitting corrosion was distinguished from uniform corrosion in terms of the frequency of events in the stochastic analysis. Accordingly, the present analysis method allowed us to investigate pitting corrosion independently. The susceptibility to pitting corrosion was appropriately evaluated by determining ...

International Nuclear Information System (INIS)

A commercial CFD code, Fluent, has been used to analyse the design of a filter-press reactor operating with characteristic linear flow velocities between 0.024 and 0.192 m s-1. Electrolyte flow through the reactor channel was numerically calculated using a finite volume approach to solve the Navier-Stokes equations. The length of the channel was divided into 7 sections corresponding to distances of 0, 0.01, 0.04, 0.08, 0.12, 0.14 and 0.15 m from the electrode edge nearest to the inlet. The depth of the channel was divided into three planes parallel to the channel bottom. For each channel section, a velocity profile was obtained at each depth together with the average velocity in each plane. The flow predictions show that the flow development, as the electrolyte passes through the cell, is strongly affected by the manifold causing strong vortex structures at the entrance and exit of the channel. Although the flow disturbances are a function of the flow rate, they ...

Energy Technology Data Exchange (ETDEWEB)

Two pilot-scale constructed wetlands (4:1 length:width aspect) were designed for tertiary treatment of refinery effluent. As requirements for removal of contaminants from NPDES effluents become more stringent, cost-effective technological approaches are needed to achieve the necessary treatment levels and be efficient, effective and low maintenance. The fundamental design of these constructed wetlands was based on biogeochemical principles that regulate the fate and persistence of the targeted elements (Cu, Zn, Pb). In order to maximize opportunities to learn more about the internal function of the wetlands, they were built to operate in series or in parallel permitting hydraulic retention times of 24 to 48 hours. The wetlands were lined with {approximately}76 cm of compacted clay as well as a 30 mil polyethylene liner. The hydrosoil selected for use in the constructed wetlands is 74.1% sand, 25.6% silt, 0.3% clay. Based on laboratory studies, ...

International Nuclear Information System (INIS)

An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted during the period March 30 to April 14,1992. The purpose of the survey was to measure and document the terrestrial radiological environment of the Oak Ridge Reservation for use in environmental management programs and emergency response planning. The aerial survey was flown at an altitude of 150 feet (46 meters) along a series of parallel lines 250 feet (76 meters) apart and included X-10 (Oak Ridge National Laboratory), K-25 (former Gaseous Diffusion Plant), Y-12 (Weapons Production Plant), the Freels Bend Area and Oak Ridge Institute for Science and Education, the East Fork Poplar Creek (100-year floodplain extending from K-25 to Y-12), Elza Gate (former uranium ore storage site located in the city of Oak Ridge), Parcel A, the Clinch River (river banks extending from Melton Hill Dam to the city of Kingston), and the CSX ...

DEFF Research Database (Denmark)

Udgivelsesdato: 1991-null

Science.gov (United States)

Several features make Java an attractive choice for High Performance Computing (HPC). In order to

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

Chloride-induced pitting corrosion of stainless steel (Materials No. 1.4301 and 1.4571) was investigated with the aid of chronopotentiostatic tests. Oxide films upon the surface (temper colours), addition of inhibitors (sulphate and nitrate) and temperature were the testing variables. Two different critical pitting potentials have been found, which give information on the potential ranges for stable passivity, latent and stable pitting corrosion. The results only indicate a small effect of Mo content of the material and test temperature. The inhibitors (sulphate and nitrate) have a marked effect. Specimens with a clean surface produced by pickling are markedly more resistant against pitting corrosion than specimens with a yellow temper colour, whereas the difference in corrosion resistance between yellow and blue films is relatively small. The width of the critical potential range for ...

International Nuclear Information System (INIS)

Because of their austenitic-ferritic microstructures, duplex stainless steels offer a good combination of mechanical and corrosion resistance properties. However, heat treatments can lower the mechanical strength of these stainless steels as well as render them susceptible to intergranular corrosion (IGC) and pitting corrosion. In this study, a low-carbon (0.02%) duplex stainless steel is subjected to various heat treatments at 450 to 950 C for 30 min to 10 h. The heat-treated samples than undergo ASTM IGC and pitting corrosion tests, and the results are correlated with the microstructures obtained after each heat treatment. In the absence of Cr_2_3C_6 precipitation, #sigma#-phase precipitates render this duplex stainless steel susceptible to IGC and pitting corrosion. Even submicroscopic #sigma#-phase precipitates are deleterious for IGC resistance. Longer-duration heat treatments (at 750 to 850 C) induce chromium ...

Energy Technology Data Exchange (ETDEWEB)

Austenitic stainless steel castings, such as SCS 13, SCS 14, which consists of {delta}/{gamma} duplex phase, are extensively used as structural material in seawater environments. It is known that SCS 14 involving 2wt% Mo is more resistant to pitting corrosion than SCS 13. In this paper, effects of Mo on the pitting corrosion are discussed in terms of microstructure of the material. The corrosion behavior of the materials with different {delta} ferrite contents and cleanlinesses have been evaluated by seawater exposure testing, electrochemical polarization, and TEM-EDX analysis. The results indicate that pits mainly nucleate at nonmetallic inclusions such as MnS and {delta}/{gamma} boundaries, and materials containing {delta} ferrite above 7vol% have high pitting corrosion resistance. The nucleation at {delta}/{gamma} boundaries is assumed to be due to the segregation of P. It is considered that because ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

A study of stress corrosion cracking susceptibility of Zircaloy-4 in chloride-containing aqueous methanolic media is presented. The influence of water content is investigated in the 5-100 vol. % water range. The dependence of stress corrosion cracking on potential is evidenced. A close correlation is established with pitting susceptibility determined by a statistical analysis of induction times. A correlation with the repassivation potential is observed in the water-rich solutions. In the low water content solutions, two repassivation curves are determined according to the experimental technique. Pit morphology and fractography show a transition from aqueous to organic media. (author).

Energy Technology Data Exchange (ETDEWEB)

The bibliography contains citations concerning the pitting corrosion of copper and copper alloys by different media, with some references to methods that protect against such corrosion. Included are factors contributing to the onset of pitting corrosion. Emphasis is placed on exposure to water, especially in heat exchanger tubing and water conduits. Studies are included which examine corrosion in metals containing small amonts of copper where corrosion is attributable to changes in alloying. (Contains a minimum of 158 citations and includes a subject term index and title list.)

Science.gov (United States)

... upland development or destroyed during sand and gravel pit mining operations. Gains Increases in nonvegetated wetlands mainly through pond ... ...

UK PubMed Central (United Kingdom)

Snakebites are common among the rural population of developing countries. The severity of venomous snakebites depends on several factors, including the location of the bite, the amount of venom injected,...Full Text Available

Science.gov (United States)

monitoring of open pit mining operations. INTRODUCTION. Aerial photography has long been a useful tool for geologists. Cameras ...

Energy Technology Data Exchange (ETDEWEB)

A new on-line monitoring system has been developed for pitting corrosion monitoring of carbon steel tubes in cooling water systems. This monitoring system was found to be quite sensitive to the microbiological activity relating to pitting corrosion on a real-time basis. The value of galvanic current indicates the performance level of pitting corrosion inhibition even in biocide application. In addition, the changes in the galvanic current provide indicative information about the effectiveness in microbiological control program, even when the pressure drop measurement indicates no biofilm formation. It can be also useful in detecting a microbiological control upset. In this paper, an introduction of the new monitoring system as a microbiological control effectiveness monitor and the field test results are discussed.

Energy Technology Data Exchange (ETDEWEB)

Dilute caustic high-level radioactive waste slurries can induce pitting corrosion in carbon steel. Cyclic potentiodynamic polarization tests were conducted in simulated and actual waste solutions to determine minimum concentrations of sodium nitrate which inhibit pitting in ASTM A537 class 1 steel exposed to these solutions. Susceptibility to pitting was assessed through microscopic inspection of specimens and inspection of polarization scans. Long-term coupon immersion tests were conducted to verify the nitrite concentrations established by the cyclic potentiodynamic polarization tests. The minimum effective nitrite concentration is expressed as a function of the waste nitrate concentration and temperature.

Energy Technology Data Exchange (ETDEWEB)

In 2001, the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA/NSO) remediated six areas associated with Amchitka mud pit release sites located on Amchitka Island, Alaska. This included the construction of seven closure caps. To ensure the integrity and effectiveness of remedial action, the mud pit sites are to be inspected every five years as part of DOE's long-term monitoring and surveillance program. In August of 2006, the closure caps were inspected in accordance with the ''Post-Closure Monitoring and Inspection Plan for Amchitka Island Mud Pit Release Sites'' (Rev. 0, November 2005). This post-closure monitoring report provides the 2006 cap inspection results.

Energy Technology Data Exchange (ETDEWEB)

For the construction of underground facilities comprising access tunnels, connecting tunnels, main tunnels and disposal tunnels, a large number of tunnels will be excavated in deep rock formations. These excavations will extend hundreds kilometers in total length. Therefore, special attention must be paid, to transporting large volume of debris, ventilation, emergency escape routes in case of accident, and other factors. In addition, special attention must also paid to potential accidents which might in underground excavations, including unstable facing phenomena (such as collapse and swelling of facing at weak layer sections), spring water flow resulting collapse of rock, gas eruption, and rock burst. While considering these factors to be emphasized during the construction of geological disposal facilities, the investigation reviewed the existing working methods on individual construction technologies of access tunnels, main tunnels, connecting tunnels, disposal tunnels, and disposal ...

Energy Technology Data Exchange (ETDEWEB)

The Materials & Fuel Complex (MFC) facilities 799 Sodium Processing Facility (a single building consisting of two areas: the Sodium Process Area (SPA) and the Carbonate Process Area (CPA), 799A Caustic Storage Area, and 770C Nuclear Calibration Laboratory have been declared excess to future Department of Energy mission requirements. Transfer of these facilities from Nuclear Energy to Environmental Management, and an associated schedule for doing so, have been agreed upon by the two offices. The prerequisites for this transfer to occur are the removal of nonexcess materials and chemical inventory, deinventory of the calibration source in MFC-770C, and the rerouting and/or isolation of utility and service systems. This report provides a description of the current physical condition and any hazards (material, chemical, nuclear or occupational) that may be associated with past operations of these facilities. This information will document conditions at time of ...

Wastenet

...specialised laboratories for pharmaceutics, tissue culture and molecular biology Excellent Laboratory Facilities Tissue Culture Facilities Molecular Biology Laboratory ...

Science.gov (United States)

PMID:2042311

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Copper tubes have been widely used for water supply and heat exchangers. In such systems copper tubes often suffer from type 1 pitting-corrosion. A mechanism, of the type I pitting-corrosion on copper tubing has been presented, but a initiation mechanism of the pitting corrosion is still unknown. In this paper we aimed to clarify the initiation mechanism of the pitting corrosion. Copper-tube specimens were immersed in a circulating solution. The solution had been used for heat exchangers at a Japanese factory where the water leakage occurred by the pitting corrosion on copper tubes. The solution contained tiny precipitates resulted from corrosion of galvanized steel pipe. During the immersion test changes in the surface state of a copper tube was analyzed by in situ RAMAN (in situ Raman Spectroscopy), SEM (Scanning Electron Microscope), EPMA (Electron Probe Microanalysis), AES ...

International Nuclear Information System (INIS)

The FLAPW (full-potential linearized-augmented plane-wave) method is one of the most accurate first-principles methods for determining electronic and magnetic properties of crystals and surfaces. Until the present work, the FLAPW method has been limited to systems of less than about one hundred atoms due to a lack of an efficient parallel implementation to exploit the power and memory of parallel computers. In this work we present an efficient parallelization of the method by division among the processors of the plane-wave components for each state. The code is also optimized for RISC (reduced instruction set computer) architectures, such as those found on most parallel computers, making full use of BLAS (basic linear algebra subprograms) wherever possible. Scaling results are presented for systems of up to 686 silicon atoms and 343 palladium atoms per unit cell, running on up to 512 processors on a ...

Energy Technology Data Exchange (ETDEWEB)

The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached ...

Energy Technology Data Exchange (ETDEWEB)

This interim technical report presented a summary of results obtained from Pit Lake models developed from different simulation models. The models were used to predict stratification in a hypothetical Pit Lake. Predictions were used to assess the hydrodynamic similarities and differences between the 2 models and to determine if the models would produce similar stratification profiles for the Pit Lakes to previous models. Results showed that the models produced similar results for both temperatures and salinities. The main difference between the RMA10 and CE-QUAL-W2 model used in a previous study was found to be run time. A sensitivity analysis of the RMA10 and CE-QUAL-W2 model predictions was completed to assess the effects of segmentation; time step; lake surface area; lake orientation; and model coefficients or parameters. Results showed that the selected time step and model segmentation were appropriate, as both led to ...

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final...Full Text Available

DEFF Research Database (Denmark)

Udgivelsesdato: 2007-Feb

Energy Technology Data Exchange (ETDEWEB)

Digital optical processing (DOP) was conceived to encompass the advantages of both electronic and optical processors, which are parallelism, flexibility, and high accuracy. The authors discuss the concept of parallelism, how it applies to DOP differently than to electronic parallel processing, and other potential advantages in using DOP. A PLZT memory device is described which can perform a series of logic or memory operations. From several of these PLZT devices a DOP is constructed to illustrate some of its programmability features.

International Nuclear Information System (INIS)

In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a structure. Considerable scatter is observed in ...

International Nuclear Information System (INIS)

Corrosion of steam generator heat transfer tubes (SGHTT) is one of the important problems which affect safety operation of nuclear power plants (NPP), and the hazard of pitting corrosion of heat transfer tubes is the most serious. With an acoustic emission device, the signals during a corrosion test on SGHTT were collected and analyzed, and the corrosion points in the tubes were located accurately. The results show that pitting corrosion of heat transfer tubes has passed through three periods in its development: expansion phase, stationary phase and rapid developing phase. The corrosion damage of HTT can be found earlier with acoustic emission than any other non-destructive testing methods. Acoustic emission can be used for on-line and real-time monitoring of the safety and operation of the steam generator and has therefore a great significance. (orig.)

International Nuclear Information System (INIS)

The dependence of the inhibiting action of some surface active organic substances (SAOS) on the pitting- formation potential epsilonsub(p) has been investigated for the steel Kh25T. The study has been performed by potentiostatic method using the H_2SO_4 0.1-n-solution doped by NaCl, Na_2SO_4, in the presence of SAOS of different classes. As epsilonsub(p) shifts in positive direction from +0.6 to +1.1 V, the inhibiting action of the SAOS series (o-oxyquinoline) increases gradually till some critical potential above which SAOS favour pitting destruction of steel. This phenomenon should be considered in anodic protection in SAOS-doped solutions.

Energy Technology Data Exchange (ETDEWEB)

Types of disorders in the earth's surface as a result of open pit mining operations are analyzed. Trends for recultivation of lands are defined. Formulas are presented for calculating the economic expediency of the selected direction of recultivation.

Science.gov (United States)

... pits, waste oil and solvent storage ponds (used from the 1940s to 1971), surface storage areas, settling ponds, waste water ponds, and unlined ...

Science.gov (United States)

Features: CHUQUICAMATA, LARGE OPEN PIT MINING OPERATIONS, ROADS, HILLS Center Point Latitude: -22.3 Center Point Longitude: -68.9 (Negative numbers indicate ...

Energy Technology Data Exchange (ETDEWEB)

This study assesses the feasibility of removing the FFTF reactor vessel from its current location in the reactor cavity inside the Containment vessel to a transporter for relocation to a burial pit in the 200 Area.

Energy Technology Data Exchange (ETDEWEB)

In the corrosion aspect of container for the deep geological disposal of high-level radioactive waste, disposal concepts and the related container materials, which have been developed by advanced countries, have been reviewed. The disposal circumstances could be divided into the saturated and the unsaturated zones. The candidate materials in the countries, which consider the disposal in the unsaturated zone, are the corrosion resistant materials such as supper alloys and stainless steels, but those in the saturated zone is cupper, one of the corrosion allowable materials. By the results of the pitting corrosion test of sensitized stainless steels (such as 304, 304L, 316 and 316L), pitting potential is decreased with the degree of sensitization and the pitting corrosion resistance of 316L is higher than others. And so, the long-term corrosion experiment with 316L stainless steel specimens, sebsitized and non-sensitized, ...

Energy Technology Data Exchange (ETDEWEB)

Lateral and vertical variabilities in the bulk and mechanical properties of silicic volcanic tuff at the potential nuclear waste repository site in Yucca Mountain, NV have been evaluated. Laboratory measurements have been performed on tuff specimens recovered from boreholes located to support the design of the Exploratory Studies Facility/North Ramp. The data include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. Data from eight boreholes aligned in a northwest-southeast direction have been collected under the required quality assurance program. Three boreholes have penetrated the potential repository horizon. The information collected provides for an accurate appraisal of the variability of rock properties in the vicinity of the boreholes. As expected, there is substantial variability in the bulk and mechanical properties of the tuff ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes research and development activities at the University of Regina, Saskatchewan, Canada on Optimization of CO{sub 2} Extraction Process Technologies. The ultimate goal of this research is to develop better and more effective CO{sub 2} separation processes which can be used to recover CO{sub 2} from industrial sources such as coal-fired power plants and coal gasification complexes at the lowest possible capital and operating costs. The research program has been supported by Saskatchewan Power Corporation, Saskatchewan Energy and Mines, Prairie Coal Ltd., the Canada Centre for Mineral and Energy Technology (CANMET), Fluor Daniel Inc. (USA), Sulzer Chemtech (Switzerland), Wascana Energy Inc., and Natural Sciences and Engineering Research Council of Canada (NSERC). Currently, six parallel and complementary projects have been carried out at the Process Systems Laboratory. These projects are: (1) Searching for new sterically ...

Energy Technology Data Exchange (ETDEWEB)

Formaldehyde oxidation was examined in a laboratory reactor over alumina-supported Pt, Pd, Rh, Ag, Cu-Cr, and Pd-Ag catalysts as part of a program to develop catalysts for lean-exhaust methanol-fueled vehicles. In general, the H/sub 2/CO oxidation behavior of the catalysts paralleled the CH/sub 3/OH oxidation behavior reported in Parts 1 and 2 of this series (Appl. Catal. 27(1986) 83; J. Catal. 103(1987) 419). Principal similarities were: high activity of Pt when there was no carbon monoxide (CO) in the feed, but strong inhibition by added CO; lower activity of Ag and Cu-Cr catalysts, but only weak inhibition due to added CO; enhanced activity of the Pd-Ag catalyst compared to Pd and Ag alone for feeds containing CO in addition to H/sub 2/CO; and, relatively poor activity of the Rh catalyst. The most unusual behavior was observed with the Pd catalyst, which showed local minima in the H/sub 2/CO conversion vs. temperature profiles. These saddles ...

Energy Technology Data Exchange (ETDEWEB)

Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of <10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload capability of 20 kA. The isolated output ...

Energy Technology Data Exchange (ETDEWEB)

Nitrite is to be used to inhibit pitting corrosion during Extended Sludge Processing (ESP) at the Savannah River Plant. The required nitrite concentrations are expressed as a function of the slurries' nitrate ion concentration and temperature. In the most dilute slurries, the nitrite inhibitor requirement is independent of the nitrate ion concentration and depends only on the temperature of the waste. The nitrate-independent concentration ensures that there is sufficient inhibitor, in sludge slurries whose nitrate has been depleted by radiolysis, to prevent pitting corrosion induced by other corrosive anions (e.g., sulfate and chloride). The threshold nitrate concentration at which the nitrite level is expressed as a function only of temperature is 0.02 M.

International Nuclear Information System (INIS)

The results have been presented of DC polarization and exposure investigations of alloy steels used as construction materials in flue gas desulphurization installations. on the base of analysis of composition of investigated steels and results of polarization studies, conditions have been discussed in which the pitting resistance equivalent (PRE) should be used. Among tested steels the significantly highest resistance to pitting corrosion is exhibited by 654SMO steel, classified as the super austenitic grade. (author). 14 refs, 3 figs, 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

This study examines the effects of blasting on waste dumps at open pit mining operations. Of specific concern were mining operations at the base of a five hundred foot high waste dump such as the operation at the South Pit of the Smoky-River Coal Ltd. property near Grande Cache, Alberta. An assessment of waste dump stability including factors such as quasi-static deformation behaviour, historical dump deformation behaviours and potential blasting effects was undertaken. It is concluded that safe blasting may be carried out in proximity to waste dumps, but monitoring of dump behaviour is recommended to ensure operational safety. 22 refs., 4 apps.

Energy Technology Data Exchange (ETDEWEB)

[sup 13]C epitaxial diamond films have been grown on [sup 12]C-type IIb diamond substrates doped with boron, using electron assisted chemical vapor deposition. The relation between etch pits to dislocations in [sup 13]C diamond film and the broadening of the first-order Raman peak was examined. The reactant gas was [sup 13]CH[sub 4] of > 99% purity. The substrate temperature was varied from 943 to 1300 C. The uneven surface morphology was confirmed by atomic force microscopy (AFM) and laser microscopy. From 943 to 1030 C, etch pit rows along left angle 100 right angle were observed. At 991 C, the etch pit density on a row was 3300 to 5000 pits/cm. The Ar[sup +] laser beam was focused on a transparent area near the row of etch pits, where the boron impurity of the substrate is less than several 10 ppm. The first-order Raman line of [sup 13]C epitaxial diamond film was broadened to ...

Science.gov (United States)

... Tactical Electronic Warfare Division (Code 5700) Visualization Laboratory Transportable step frequency radar Vehicle development laboratory ...

Energy Technology Data Exchange (ETDEWEB)

This report details an investigation into the efficacy of two approaches to solving the radiation diffusion equation within a radiation hydrodynamic simulation. Because leading-edge scientific computing platforms have evolved from large single-node vector processors to parallel aggregates containing tens to thousands of individual CPU's, the ability of an algorithm to maintain high compute efficiency when distributed over a large array of nodes is critically important. The viability of an algorithm thus hinges upon the tripartite question of numerical accuracy, total time to solution, and parallel efficiency.

Energy Technology Data Exchange (ETDEWEB)

This Corrective Action Investigation Plan contains the U.S. Department of Energy, Nevada Operations Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 409 under the Federal Facility Agreement and Consent Order. Corrective Action Unit 409 consists of three Corrective Action Sites (CASs): TA-53-001-TAB2, Septic Sludge Disposal Pit No.1; TA-53-002-TAB2, Septic Sludge Disposal Pit No.2; and RG-24-001-RGCR, Battery Dump Site. The Septic Sludge Disposal Pits are located near Bunker Two, close to Area 3, on the Tonopah Test Range. The Battery Dump Site is located at the abandoned Cactus Repeater Station on Cactus Peak. The Cactus Repeater Station was a remote, battery-powered, signal repeater station. The two Septic Sludge Disposal Pits were suspected to be used through the late 1980s as disposal sites ...

UK PubMed Central (United Kingdom)

Amphibians are considered reliable indicators of environmental quality. In the western United States, a general decline of frog populations parallels an apparent worldwide decline. The factors thought...Full Text Available

Science.gov (United States)

... potential propagation in terminal nerve fibers or at the neuromuscular ... means of prosthesis control (Graupe, et al, 1975). ... parallel interface, a joystick ...

International Nuclear Information System (INIS)

We investigate the magnetic braking of the core of an axisymmetric cloud whose rotation axis is parallel to the mean direction of the magnetic field. (author).

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 ...

Energy Technology Data Exchange (ETDEWEB)

The goal of this project is to provide materials engineers, chemical engineers and plant operators with a software tool that will enable them to predict localized corrosion of process equipment including fabricated components as well as base alloys. For design and revamp purposes, the software predicts the occurrence of localized corrosion as a function of environment chemistry and assists the user in selecting the optimum alloy for a given environment. For the operation of existing plants, the software enables the users to predict the remaining life of equipment and help in scheduling maintenance activities. This project combined fundamental understanding of mechanisms of corrosion with focused experimental results to predict the corrosion of advanced, base or fabricated, alloys in real-world environments encountered in the chemical industry. At the heart of this approach is the development of models that predict the fundamental parameters that control the occurrence of localized ...

Energy Technology Data Exchange (ETDEWEB)

This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide.

UK PubMed Central (United Kingdom)

The effect of abatacept, a selective T-cell co-stimulation modulator, on vaccination has not been previously investigated. In this open-label, single-dose, randomized, parallel-group, controlled study,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Researchers investigated several supercomputer architectures in the context of assessing their performance in solving PDE problems. Main results are: assessed various classes of paralled and vector supercomputers and parallel software issues toward solving PDE problems; developed a multipipeline networking technique for compound vector processing; developed an orthogonal multiprocessor for large-grain scientific computations; improved parallel efficiency of a domain decomposition method, the DD algorithm.

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

The corrosion behaviour of friction stir welded (FSW) joints of AA 5083 has been compared to that of MIG welded joints. Pitting and stress corrosion cracking (SCC) resistance in 3.5% NaCl + 0.3 g/l H{sub 2}O{sub 2} and in EXCO (4 M KCl + 0.5 M KNO{sub 3} + 0.1 M HNO{sub 3}) solutions has been determined at 25 C. SCC susceptibility was evaluated by slow strain rate tests (SSRT), at a strain rate of 1 x 10{sup -6}s{sup -1}. Welds obtained by FSW technique showed a higher corrosion resistance in EXCO solution and a lower pitting tendency than the base alloy. Electrochemical measurements (corrosion potential measurements, polarization curves recording) evidenced that FSW weld was cathodic to base alloy. FSW joints were not susceptible to SCC in both test solutions, whereas MIG joints cracked in both solutions. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The thermal-hydraulic performance in periodic frosting conditions is experimentally studied for the parallel-flow parallel-fin heat exchanger, henceforth referred to as a PF{sup 2} heat exchanger, a new style of heat exchanger that uses louvered bent fins on flat tubes to enhance water drainage when the flat tubes are horizontal. Typically, it takes a few frosting/defrosting cycles to come to repeatable conditions. The criterion for the initiation of defrost and a sufficiently long defrost period are determined for the test PF{sup 2} heat exchanger and test condition. The effects of blower operation on the pressure drop, frost accumulation, water retention, and capacity in time are compared under the conditions of 15 sequential frosting cycles. Pressure drop across the heat exchanger and overall heat transfer coefficient are quantified under frost conditions as functions of the air humidity and air face velocity. The performances of two types ...

Energy Technology Data Exchange (ETDEWEB)

The pitting resistance of Fe-Cr and Fe-Cr-Mo alloys has been correlated with characteristics of the passive films analyzed by Auger electron spectroscopy (AES). Increased film protectiveness as a result of increased Cr in the alloy can be directly attributed to Cr enrichment of the film and decreased film thickness. Increased Mo in the alloy or passivation at noble potentials promotes passive film resistance to breakdown, but neither does much to change the macrocharacteristics of the film. Rather, it is suggested that the roles of alloying and/or passivation conditions are related to the susceptibility and distribution of weak points of the film. In solutions in which pitting occurs, chloride is generally not incorporated into the film, suggesting that the role of halides is to interact with weak points of the film at the solution/film interface. At 260/sup 0/C, the films are much thicker and likely to be much more defective in structure than ...

International Nuclear Information System (INIS)

The surface films formed on type 316LN stainless steels (SS) with different nitrogen contents, during potentiodynamic polarization in acidified 1 M NaCl solution, were characterized by Laser Raman Spectroscopy (LRS). LRS confirmed the presence of oxides and oxychlorides of iron and chromium, hydrated chlorides and nitrates in the film. Raman mapping showed increasing nitrate content in the film with increasing nitrogen content. The film on the uncorroded material showed the presence of chromium and molybdenum oxides. The improvement in pitting corrosion resistance of type 316LN SS with increasing nitrogen content was attributed to increased amount of nitrates in the passive film.

Energy Technology Data Exchange (ETDEWEB)

Passive films were formed on a high purity Fe-23 Cr alloy in acid sulfate solutions in the presence and absence of chloride ion. The resulting film composition was investigated by Auger depth profiling. The passivated samples were exposed to a 1M NaCl solution at a constant potential slightly above the critical pitting potential, and the current-time transient was measured in order to compare the relative stability of the different films. The results obtained suggest that the formation conditions influence the chloride content of the passive film and the breakdown behavior. Passive films formed in the presence of chloride contain and are slightly less stable towards breakdown. No chloride was found in films formed in sulfate and subsequently exposed to chloride well below the pitting potential.

UK PubMed Central (United Kingdom)

Over the past 10 years, the Peruvian National Tuberculosis (TB) Program, the National Reference Laboratory (NRL), Socios en Salud, and US partners have worked to strengthen the national TB laboratory...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

There is increasing pressure to operate laboratory facilities in environmentally and financially sustainable ways. A key factor in achieving this goal is careful consideration of how energy is used by the buildings' ventilation system, both for conditioning air supplied to the laboratories and the energy used moving air through the building. Traditionally, laboratory energy use is treated as an engineering concern within the scope of the building's overall design and operation. However, this approach limits the involvement of key stakeholders in many important decisions and can lead to unexpected safety concerns for the laboratory's users. We believe that a broad view of the parties affected by a laboratory building's operations is necessary to avoid having the various stakeholders working...

Science.gov (United States)

as manufacturing plants and laboratories, including the Chemical Laboratory at the House of David in Benton Harbor, Michigan. Built in America: Historic Building Buildings Survey/...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this statement of work (SOW) is to establish laboratory analytical criteria and requirements for radioactive airborne emissions measurement sample and/or analysis activities.

Energy Technology Data Exchange (ETDEWEB)

This document details monthly activities at the Savannah River Laboratory. Topics addressed are reactor operation; tritium facilities and production; separation operations; environmental concerns; and waste management. (FI)

Science.gov (United States)

Publications Science Highlights Researcher Profiles Internship Funding to push battery technology from Argonne Laboratory to marketplace Bookmark and Share (Download...

Energy Technology Data Exchange (ETDEWEB)

This article deals with excavation equipment used in open-pit mining operations. Because of competition in the mining industry, a demand for more energy-efficient excavators is being felt. The authors present different types of machinery and give statistics on energy use, weights, bucket capacity, and maximum digging depths. Actual manufacturers specifications are also given for different models. A short discussion on the role computers are playing in this new technology is also given.

Energy Technology Data Exchange (ETDEWEB)

Reflective diffraction grating. A focused ion beam (FIB) micromilling apparatus is used to store color images in a durable medium by milling away portions of the surface of the medium to produce a reflective diffraction grating with blazed pits. The images are retrieved by exposing the surface of the grating to polychromatic light from a particular incident bearing and observing the light reflected by the surface from specified reception bearing.

International Nuclear Information System (INIS)

As an unconventional surface alloying process, ion implantation has been utilized to improve the active-passive behavior and the pitting resistance of martensitic M50 engineering alloy. In a field simulation study, Cr-implantation only at 150 kev to a fluence of 2 x 10"1"7 ions/cm"2 prevented pitting. The best pitting resistance of the steel was obtained with multiple implantations of Cr and Mo. The intermixing effect of high fluence P-implantation into 304 stainless produced an amorphous surface alloy. The removal of the grain boundaries and the uniformity of the resulting structure had a great influence on corrosion properties. REED analysis indicated that the anodic passive films formed on P-implanted 304 stainless steel at 250 mV (SCE) in 0.5M H_2SO_4 was amorphous. Phosphorus and boron were implanted into 316 stainless steel to study the passivity of 316 stainless. Electrochemical experiments were carried out to ...

Science.gov (United States)

The reports in this series are designed primarily to familiarize professional land use and resource planners with the range of possibilities and effective procedures for achieving integrated mining, reclamation, and land use planning. These reports are ba...

Energy Technology Data Exchange (ETDEWEB)

Electrochemical cyclic potentiodynamic polarization (CPP) experiments were performed on several candidate high-performance waste package container materials to evaluate their susceptibility to localized corrosion in aqueous environments relevant to the potential underground high-level nuclear waste repository. This paper presents the results of this study showing the effects of chloride ion (Cl) concentrations, pH, temperature, and electrochemical potential scan rate on the pitting corrosion behavior of these materials.

Energy Technology Data Exchange (ETDEWEB)

For large transmission steel towers to be built in a mountainous area, caisson type pile foundations are often applied. The works for construction of this kind of foundation are manned operations such as drilling, arranging reinforcements, concrete laying, etc. in a narrow vertical pit which is 3m in diameter and about 20m in depth, but securing labour force of good quality for such works becomes increasingly difficult. In order to cope with the above situation and achieve reduction of costs, shortening of construction period, improvement of safety, saving of manpower, etc. a power supply company and construction companies have developed jointly a method of unmanned construction in a caisson type pile foundation pit. This method consists of the use of a caisson type pile full size excavator (this consists of an excavator proper, a vacuum soil discharging device, a monitor/controller, a load crane and a reaction pad, and performs continuously ...

Energy Technology Data Exchange (ETDEWEB)

Pitting corrosion and trans-passive dissolution of 316 stainless steel in solution containing five percent of commercial bleaching liquid was investigated by employing potentiodynamic polarization method and recording corrosion potential during immersion. Today commercial bleaching liquids are widely used as cleaner additives, therefore, those house appliances made from stainless steels are in contact with aqueous solution containing bleaching liquid. This may cause sever localized corrosion and trans-passive dissolution. In order to investigate the possibility of trans-passive dissolution of stainless steel by bleaching liquid, potentiodynamic polarization and recording variation of corrosion potential of specimens were carried out in 0.2 M Na{sub 2}SO{sub 4} solution containing 5 %wt. commercial bleaching liquid. A 500 mV drop in trans-passive potential and also instantaneously ennobling corrosion potential revealed the possibility of trans-passive dissolution ...

Energy Technology Data Exchange (ETDEWEB)

Thick-target recoil ranges of radioactive nuclei produced in 30-200 MeV alpha-particle bombardment of /sup 59/Co have been used to deduce the longitudinal momentum transfer per projectile nucleon (psub(parallel)/A) as a function of residue mass and bombarding energy. The average value of psub(parallel)/A increases monotonically with bombarding energy and reaches a maximum value of proportional160 MeV/c at proportional23 MeV/u, and decreases thereafter. The maximum value of psub(parallel)/A is equal to the incident momentum up to proportional23 MeV/u and saturates at a value of proportional220 MeV/c beyond this energy.

British Library Electronic Table of Contents (United Kingdom)

We investigate how, and to what extent, morphological complexity of the language influences text classification using support vector machines (SVM). The Croatian-English parallel corpus provides the basis for direct comparison of two languages of radically different morphological complexity. We quantified, compared, and statistically tested the effects of morphological normalisation on SVM classifier performance based on a series of parallel experiments on both languages, carried over a large scale of different feature subset sizes obtained by different feature selection methods, and applying different levels of morphological normalisation. We also quantified the trade-off between feature space size and performance for different levels of morphological normalisation, and compared the resul...

International Nuclear Information System (INIS)

We develop a large scale parallel viscous-elastic analysis program incorporating a mesoscopic self-consistent model developed by Laws. In the model, macroscopic elastic constants are treated as variables depending on the shape and statistical properties of pre-existing microscopic pores and change due to neutron irradiation. We apply this program to the visco-elastic analysis of nuclear graphite structures under neutron irradiation environment in High Temperature Gas-cooled Reactor (HTGR), as an example problem. Furthermore the calculated results by this parallel computational program are compared with those by one of commercial finite element analysis codes, FINAS, for validating elastic and thermal stress analysis function. (author)

CERN Document Server

In this paper, we describe our vectorized and parallelized adaptive mesh refinement (AMR) N-body code with shared time steps, and report its performance on a Fujitsu VPP5000 vector-parallel supercomputer. Our AMR N-body code puts hierarchical meshes recursively where higher resolution is required and the time step of all particles are the same. The parts which are the most difficult to vectorize are loops that access the mesh data and particle data. We vectorized such parts by changing the loop structure, so that the innermost loop steps through the cells instead of the particles in each cell, in other words, by changing the loop order from the depth-first order to the breadth-first order. Mass assignment is also vectorizable using this loop order exchange and splitting the loop into $2^{N_{dim}}$ loops, if the cloud-in-cell scheme is adopted. Here, $N_{dim}$ is the number of dimension. These vectorization schemes which eliminate the ...

UK PubMed Central (United Kingdom)

SummaryThe Hippo tumor-suppressor pathway controls tissue growth in Drosophila and mammals by regulating cell proliferation and apoptosis. The Hippo pathway includes...Full Text Available

UK PubMed Central (United Kingdom)

In this work, we explore the potential of the metalloendopeptidase Lys-N for MALDI-MS/MS proteomics applications. Initially we digested a HEK293 cellular lysate with Lys-N and, for comparison, in parallel...Full Text Available

UK PubMed Central (United Kingdom)

The receptive field of a neuron reflects its function. For example, for parallel fiber (PF) inputs in C3 zone the cerebellar cortex, the excitatory and inhibitory receptive fields of a Purkinje cell...Full Text Available

UK PubMed Central (United Kingdom)

Plastid genome content and arrangement are highly conserved across most land plants and their closest relatives, streptophyte algae, with nearly all plastid introns having invaded the genome in their...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

Science.gov (United States)

Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.

UK PubMed Central (United Kingdom)

BackgroundA strong association between stress resistance and longevity in multicellular organisms has been established as many mutations that extend lifespan also show increased...Full Text Available

UK PubMed Central (United Kingdom)

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed...Full Text Available

UK PubMed Central (United Kingdom)

A quantum computer (QC) can operate in parallel on all its possible inputs at once, but the amount of information that can be extracted from the result is limited by the phenomenon of wave function...Full Text Available

UK PubMed Central (United Kingdom)

AbstractDendrites of cerebellar Purkinje cells (PCs) respond to brief excitations from parallel fibers with lasting plateau depolarizations. It is unknown whether these plateaus are local...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

One of the central questions of molecular biology is the discovery of the semantics of DNA. This discovery relies in a critical way on a variety of expensive computations. In order to solve these computations, both parallel computers and special-purpose hardware play a major role.

UK PubMed Central (United Kingdom)

Besides ethanol, acetic acid is produced in naturally fermenting sweet resources and is a significant environmental stress for fruit-breeding Drosophila populations and species. Although not related...Full Text Available

Science.gov (United States)

PMID:20812517

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

In 1963, Grover and co-workers at the Los Alamos. Scientific. Laboratory ...... and A. P. Watkins. (1986) "The Computation of Compressible ...

CERN Document Server

The whole computer hardware industry embraced multicores. For these machines, the extreme optimisation of sequential algorithms is no longer sufficient to squeeze the real machine power, which can be only exploited via thread-level parallelism. Decision tree algorithms exhibit natural concurrency that makes them suitable to be parallelised. This paper presents an approach for easy-yet-efficient porting of an implementation of the C4.5 algorithm on multicores. The parallel porting requires minimal changes to the original sequential code, and it is able to exploit up to 7X speedup on an Intel dual-quad core machine.

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Results obtained on induced current and voltage caused by a high voltage transmission lines running parallel at a trolley bus contact lines, are presented. A computer program in Basic language, was developed to calculate the electric induction, problems of safety, a theoretical development and mathematical model of the electric factors between two lines (inductor and induced) are also discussed. 11 figs., 1 tab., 8 refs.

British Library Electronic Table of Contents (United Kingdom)

The contention of this commentary, focused on the vestibulocerebellum (particularly the flocculus), is that the great importance for our understanding of cerebellar organization in terms of climbing fiber zones, begun years ago by Voogd [1969, 2011] and Oscarsson [1969], needs to be matched by coming more to grips with the other fundamental geometrical organization of the cerebellum, the parallel fibers. The central issue is the selection of those parallel fiber signals to be transformed into Purkinje cell activity in the different zones. At present, in comparison to our knowledge of vestibulocerebellar climbing fiber inputs, the deficiencies in our knowledge of the zonal anatomy and physiology of vestibulocerebellar mossy fibers and granule cells are glaring. The recent emphasis on molecu...

International Nuclear Information System (INIS)

A nuclear power plant engineering (NPP) simulator may include many system functions such as thermal-hydraulic calculation, 3D reactor neutron kinetics model, control and protection system, display and operational human-machine interface, intelligent alarm system, etc. If all those functions are simulated using a single code, the size of the program will cause structural or managerial problems, and the hardware requirement could be tremendous. Thus, any local function errors or changes may affect the whole code, which will make development and maintenance extremely costly. So the nondistributed code is not considered to be flexible and feasible. Currently, distributed and parallel technologies have been applied to develop NPPs engineering simulator for safety analysis, verification of advanced main control room display, operation and intelligent alarm design. The distributed simulation divides a huge task into several objects according to different functions. ...

International Nuclear Information System (INIS)

To encourage the application of robotics technology for routine radiobench applications, a laboratory dedicated to the research and development of contained robotic systems is being constructed. The facility will have several robots located in laminar flow hoods, and the hoods are being designed to allow the possibility for multiple robots to work together. This paper presents both the design features of the hoods and the general layout of the laboratory, and also discusses an application of a robotic system for the routine nuclear counting of gamma tube samples. The gamma tube system is presently operating in one of the routine analysis laboratories. 5 figs.

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The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) Laboratory Directed Research and Development Program FY 1996 report is compiled from annual reports submitted by principal investigators following the close of the fiscal year. This report describes the projects supported and summarizes their accomplishments. It constitutes a part of the Laboratory Directed Research and Development (LDRD) program planning and documentation process that includes an annual planning cycle, projection selection, implementation, and review. The Berkeley Lab LDRD program is a critical tool for directing the Laboratory`s forefront scientific research capabilities toward vital, excellent, and emerging scientific challenges. The program provides the resources for Berkeley Lab scientists to make rapid and significant contributions to critical national science and technology problems. The LDRD program also ...

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The potential to scrub biogas in a high rate pond (HRP) was evaluated using apparatus designed to maximize gas-liquid contact. Experiments compared the removal of carbon dioxide from synthetic biogas by an 'in-pond angled gutter' to that by a simulated 'counter-current pit'. Results showed that the counter current pit has potential for use in biogas scrubbing, with synthetic biogas carbon dioxide composition consistently reduced from 40% to<5%. The in-pond angled gutter was less effective due to bubble coalescence which reduced the total bubble surface surface area available for gas transfer. Measurement of oxygen levels in the scrubbed biogas showed that despite supersaturation of oxygen in the HRP water, there was little transfer to the biogas, so that explosive methane/oxygen mixtures would not be formed. Theoretical calculations indicated that the amount of biogas likely to be formed during ...

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Monitoring of groundwater quality from boreholes in and around the former Yotsugi open-pit mining site in the Ningyo-toge Environmental Engineering Center, JNC, have been carried out to estimate extent and quality of contaminated water plume from the buried heap-leaching residue. In this report, data collected from 1979 to 1998 fiscal year were listed and their spatial and time variation of physicochemical parameters, uranium and radium were also summarized. Additionally, groundwater sampler has been improved and analytical method has been modified. Some results from groundwater quality were; 1. Generally, electric conductivity and concentrations of uranium and radium outside of the site tend to lower than one from the inside area. 2. Data from borehole No. 13, installed outside of the site, exceptionally little higher than one from the inside area. (author)

International Nuclear Information System (INIS)

PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition minimizes OD-initiated ...

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In order to enhance the resistance to the pitting corrosion due to asepsis processes and to avoid structural fractures in dentistry drills, a plasma immersion ion implantation (PIII) treatment using nitrogen has been performed. The selected drill samples, made of AISI 434 based stainless steel with a 0.670 mm diameter, were treated at a -1kV bias between 350 C and 450 C, this temperature being controlled by both a 20-50 {mu}s pulse width and a 200-1000 Hz repetition rate in the bias. The drills were analysed by cyclic potentiodynamic tests showing a good pitting corrosion resistance when treated at around 400 C, as follows from a resulting very low hysteresis loop. Yet, the resistance appears somehow diminished by the presence of sputtering when processed at temperatures near 450 C. It is also found that the PIII nitriding effectiveness appears to be limited by the appearance of uniform corrosion. Finally, X-ray diffraction of the samples has ...

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The passivation of low carbon steel was studied in aqueous solution of 0.5M Na[sub 2]SO[sub 4]+0.001M NaHSO[sub 3] (pH 3.5, 6.5 and 8.5) which can be considered as a model of acid rain. The used conversion electron Moessbauer spectroscopy (CEMS) with the complementary electrochemical investigations proved that the sulfite ions induce pitting corrosion at pH 3.5 and 6.5, while the measurements showed much weaker pitting at pH 8.5. The compositions and thicknesses of the passive films formed during the electrochemical treatments are determined from the CEM spectra. Only [gamma]-FeOOH was found on the surface of the samples at pH 6.5 and 8.5. Nevertheless, at pH 3.5 the sextet belonging to Fe[sub 3]C appears in the spectra, and also FeSO[sub 4].H[sub 2]O could be detected in low concentration. (orig.).

International Nuclear Information System (INIS)

Semiconducting properties of passive films formed on AISI 304 stainless steel grade were investigated by capacitances measurements in chloride containing aqueous solutions for different surface finishes: BA (bright annealing in hydrogen containing atmospheres) and 2B (standard annealing in oxidising atmospheres followed by pickling in acid, then water rinsing). Mott-Schottky analysis shows that for high enough electrode potential, and whatever the surface finish, the films behave like n-type semiconductors. 2B passive film appears to be more donor-doped than BA one and the density of donor states increases with chloride concentration. The electron donor levels are assumed to be generated by negatively charged cations vacancies produced by the chloride ions reaction with the outer passive film. This reaction looks easier for 2B than BA condition, which explains why BA resists better than 2B to pit nucleation.

Energy Technology Data Exchange (ETDEWEB)

Complementary electrochemical, spectrophotometric and electron microsopic investigations were made in addition to the conversion electron Moessbauer spectroscopic (CEMS) measurements to learn more about the mechanism of corrosion of low carbon steel samples in aqueous sulfate and sulfite containing sulfate solutions (pH 3.5, 6.5 and 8.5). Passivation of iron in pure sulfate solution was studied in detail in earlier papers. In the present work, we used a solution containing both sulfate and sulfite anions to obtain more information about the effect of acid rain on low carbon steel samples. The compositions and thicknesses of the passive films formed due to the electrochemical treatments were determined from the CEM spectra. [gamma]-FeOOH was found in each case on the surface of the samples; nevertheless, at pH 3.5 the sextet belonging to Fe[sub 3]C appears in the CEM spectra, and also FeSO[sub 4] . H[sub 2]O was detected in low concentration after the shortest polarization time (90 ...

International Nuclear Information System (INIS)

A review of the performance of steam generator tubes in 116 water-cooled nuclear power reactors showed that tubes were plugged at 54 (46 percent) of the reactors. The number of tubes removed from service decreased from 4 692 (0.30 percent) in 1981 to 3 222 (0.20 percent) in 1982. The leading causes of tube failures were stress corrosion cracking from the primary side, stress corrosion cracking (or intergranular attack) from the secondary side and pitting corrosion. The lowest incidence of corrosion-induced defects from the secondary side occurred in reactors that have used only volatile treatment, with or without condensate demineralization.

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McLeod River Coal Ltd., a wholly owned subsidiary of Manalta Coal Ltd., has received Alberta Energy Resources Conservation Board approval to establish an open pit coal mine and plant in the northwest portion of the Coalspur field, east of Hinton. McLeod proposes to produce up to 4.2 million tonnes/year of thermal coal for 40 years, starting in 1985. The commercial viability of the project must be assessed before construction starts at the McLeod River site. The Board's ruling is subject to provincial cabinet approval.

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This article outlines the use of gasifiers during World War II and how, with soaring fuel prices, producer gas may provide an alternate energy path for agribusiness and farms today. In the last few years, the University of California has become a focus of producer gas research in the US. Biomass fuels used include crushed walnut shells, fruit pits, cereal straw and corn cobs. Particle size, moisture content and slagging create problems and the right kind of gas producer must be used to obtain reliable conversion to producer gas.

Energy Technology Data Exchange (ETDEWEB)

We investigated the effects of additives to the etching solution of 1 M hydrochloric acid on the electrochemical etching behavior for aluminum electrolytic capacitors, using scanning and transmission electron microscopy, and AC impedance spectroscopy. For the addition of 1 M sulfuric acid or 5% ethylene glycol to the hydrochloric acid solution, the distribution of etch tunnels was more uniform with high density of etch pits compared with that without addition. The highest specific surface area was obtained from the electrolyte with 5% ethylene glycol additive. The correlation of internal morphologies of etched foils with impedance parameters was interpreted by impedance techniques.

International Nuclear Information System (INIS)

The mechanism of the salt concentration increase in pits and crevices formed in a steam generator due to its imperfect manufacture or to its design features is described. The probability of corrosion can be reduced by choosing a suitable steel and by securing low concentrations of salts (chlorides in particular) and corrosion products in the feedwater. Attention is paid to the distribution of salts in the water-steam circuit and to the conditions of erosion corrosion as the principal source of corrosion products in feedwater. Experience with the suppression of erosion corrosion at nuclear power plants abroad is described. (E.J.).

Energy Technology Data Exchange (ETDEWEB)

For evaporation crystallization of extremely corrosive FGD scrubber solutions which - depending on the process - can lead all the way to a product suitable for depositing, an economic equipment concept based on metallic construction materials was to be investigated. In a parameter study, electrochemical test methods were used to determine the influence of the pH value, the Fe{sup 3+}, F and So{sub 2} contents in a solution containing 200 g/l CaCl{sub 2}+30 g/l NaCl at 80deg C on the resistance to pitting corrosion of stainless steels and NiCrMo alloys. In addition, electrochemical and wet corrosion tests (e.g. crevice corrosion) were conducted using original FGD scrubber solutions with 43-50% dry substance from the power plants Reuter-West, Oberhavel and Rudow of the BEWAG, Berlin. The results were compared to those of standardized and non-standardized short-term tests for determining the critical pitting corrosion and crevice corrosion ...

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A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.

Energy Technology Data Exchange (ETDEWEB)

An analysis of the current state of track-laying operations in open-cut mines is given and their labor intensive nature is noted. The lag in the technological development of mechanization equipment for track laying and repair operations is noted. Results are given from developments by the Scientific Research Institute of Open-Pit Mining Operations in the field of mobile transportation technology and promising modular route design. Also examined are the problems of improving the routing bases in the industry. The absence of factories for manufacturing transportation technology and equipment is reflected most evidently in the technical and cost characteristics of coal production by an open-cut method and requires immediate solution.

Energy Technology Data Exchange (ETDEWEB)

By magnetron sputtering model steel films with specific properties can be prepared for purposive surveys. By changing the deposition parameters certain properties of these films can be influenced. For this thesis steel films with 18% Cr and 8% Ni have been prepared in order to study specific parameters on the corrosion resistance of bulk stainless steel. Chemical composition, microstructure, and surface morphology of these films have been characterized. In comparison to bulk steel sheets with the same chemical composition they have a smaller grain size and a ferritic structure. In contrast to bulk steel sheets they don`t contain any nonmetallic inclusions like Mn-sulfides. The influence of these structural differences on the corrosion resistance has been studied. For this purpose the electrochemical properties of the sputter-deposited steels have been compared with the properties of steel sheets with a similar chemical composition (DIN 1.4301, AISI 304) in neutral and acidic Cl{sup ...

International Nuclear Information System (INIS)

The activity concentrations of potassium, uranium and thorium in minerals and soil samples from a mining site in Ibadan, Southwestern Nigeria were measured using gamma ray spectroscopy method. Effective dose per annum has been calculated from the activity concentrations of dominant gamma-emitting natural radionuclides, potassium, uranium and thorium. Samples collected include minerals (beryl, quartz and feldspar), soil samples from the mining pits, heaps and undisturbed land around the mining site. The activity concentrations of "4"0K, "2"3"8U and "2"3"2Th, respectively in Bq kg-1 in the mineral samples were as follows: 1985 #+-# 16, 4.8 #+-# 0.9 and 11.8 #+-# 5.8 for beryl sample, 115.1 #+-# 27.9, 5.0 #+-# 1.3 and 6.3 #+-# 5.0 for feldspar samples and 1421 #+-# 122, <4.8 and 20.1 #+-# 3.5 for quartz samples. For the soil samples, the mean activity concentrations of "4"0K, "2"3"8U and "2"3"2Th, respectively, were 314.2 #+-# 5.7, 27.7 #+-# 2.6 and 11.5 #+-# 5.9 ...

Energy Technology Data Exchange (ETDEWEB)

Alloy 600 is commonly used in the primary systems of PWR plants because of its excellent resistance to a stress corrosion cracking and pitting. But a stress corrosion cracking and pitting corrosion are occasionally observed under PWR conditions, which may be correlated with the passive film on the Alloy 600 surface. There is little information on the composition of films growing on the surface of Alloy 600 at high temperature. Therefore, an understanding of the basic electrochemical behaviors about an anodic dissolution and the passivation of the bare surface of metals and alloys provides important information about localized corrosions like a SCC and pitting. Oxide on the steel surfaces in an aqueous solution above 100 .deg. C is composed of a duplex film structure. The inner layer of the oxide is dense and less porous, which is formed by a growth of the oxide layer on the metal surface. Outer layer of the oxide is less ...

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Metal dusting corrosion has been a serious problem in the petroleum and petrochemical industries, such as reforming and syngas production systems. This form of deterioration has led to worldwide material loss for 50 years. For the past three years, we have studied the mechanism of metal dusting for Fe- and Ni-base alloys. In this report, we present a correlation between the weight loss and depth of pits that form in Ni-base alloys. Nickel-base alloys were also tested at 1 and 14.8 atm (210 psi), in a high carbon activity environment. Higher system pressure was found to accelerate corrosion in most Ni-base alloys. To reduce testing time, a pre-pitting method was developed. Mechanical scratches on the alloy surface led to fast metal dusting corrosion. We have also developed preliminary data on the performance of weldments of several Ni-base alloys in a metal dusting environment. Finally, Alloy 800 tubes and plates used in a reformer plant were ...

UK PubMed Central (United Kingdom)

Surge capacity is the ability to rapidly mobilize to meet an increased demand. While large amounts of federal funding have been allocated to public health laboratories, little federal funding has been...Full Text Available

UK PubMed Central (United Kingdom)

A retrospective study of the relationship of season to the absorption of radiolead in laboratory rats was performed using data representing 305 animals from 36 experiments over 6 calendar years. Male...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The CWDD injector has been shipped to Argonne National Laboratory, installed, and recommissioned. Commissioning progress, operational status, and future plans are reported. Operational experience at ANL is compared with that obtained at Culham.

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This report documents site remediation at ORNL, including ORNL site characterization technologies, waste management and robotics and automation of the laboratory for waste processing and analysis.

International Nuclear Information System (INIS)

The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.

UK PubMed Central (United Kingdom)

1. Interactions of pyrazole and ethanol were studied in three laboratory test procedures. They included sleeping time in mice, rotor rod balance in rats and lever pressing behaviour of rats. 2....Full Text Available

International Nuclear Information System (INIS)

This volume described in detail the Department's research and technology development activities and their funding at the Department's laboratories. It includes 166 Mission Activity Profiles, organized by major mission area, with each representing a discrete budget function called a Budget and Reporting (B ampersand R) Code. The activities profiled here encompass the total research and technology development funding of the laboratories from the Department. Each profile includes a description of the activity and shows how the funding for that activity is distributed among the DOE laboratories as well as universities and industry. The profiles also indicate the principal laboratories for each activity, as well as which other laboratories are involved. The information in this volume is at the core of the Strategic Laboratory Mission Plan. It enables a reader to ...

UK PubMed Central (United Kingdom)

In a combined clinical, radiological, and laboratory study of 77 patients throughout the leprosy spectrum, 10 patients had an enthesitis which has not been described previously as far as is known and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This Maintenance Improvement Plan has been developed for maintenance functions associated with the 222-S Laboratory. This plan is developed from the guidelines presented by Department of Energy (DOE) Order 4330.4B, Maintenance Management Program (DOE 1994), Chapter 11. The objective of this plan is to provide information for establishing and identifying WMH conformance programs and policies applicable to implementation of DOE Order 4330.4B guidelines. In addition, this maintenance plan identifies the actions necessary to develop a cost effective and efficient maintenance program at 222-S Laboratory. Maintenance activities are mainly going to be performed by existing maintenance organizations within Waste Management Federal Services of Hanford (WMH). Most maintenance performed at 222-S Laboratory is performed by the 222-S Laboratory maintenance organization. This 222-S Laboratory ...

International Nuclear Information System (INIS)

A laboratory stream consisting of two stream sections interrupted by two pools was filled with a mixture of tap water and organically enriched water from rivers nearby. Bottom sediment material, Potamogeton pectinatus, macro-invertebrate organisms, as well as the mosquito fish, Aplocheilichthys johnstonii were collected from rivers around Johannesburg and introduced into the laboratory stream. After initial acclimatization, the distribution of the isotope "3"2P through this laboratory stream was followed. Absorption of this isotope by benthic algae, Potamogeton pectinatus, several macro-invertebrate organisms as well as Aplocheilichthys johnstonii was recorded.

Science.gov (United States)

... conditions. the Air Force Research Laboratory's Aural Displays and The advent of virtual audio technology provides as many ...

International Nuclear Information System (INIS)

... spin-lattice relaxation angular momentum electronic circuits magnetic

Science.gov (United States)

... negative diplooocci, to determine the type of pneumococi, to study staphylococa proteas, ehigla, sallmnefla, pasteurella, brucela, linters, leptosp ,s ...

International Nuclear Information System (INIS)

... Industry, Material Science Research Laboratory, Yokosuka, Kanagawa (Japan)

Science.gov (United States)

... These are abnormal and an indication of NAVAIRINST 13340.3 identifies these laboratories a possible breakdown in the fuel-handling equip- ...

International Nuclear Information System (INIS)

(Jun 1984). United States Clough, RL Gillen, KT Sandia Nat'l Laboratories

Energy Technology Data Exchange (ETDEWEB)

This paper describes TENT, a system designed for integrating the various tools and parts of a CFD simulation system (CFD - Computational Fluid Dynamics) and the simulation code itself in one interactive simulation environment. Initially the system was intended to be a TEstbed for Numerical Turbine simulation but it turned out that the approach was general enough to be suitable for more complex simulation tasks in the field of aircraft simulation. The paper will give a brief description of a CFD simulation system and its component interactions, which are the basis for describing the Component Architecture based on CORBA. This includes the control architecture using an event model and data flow considerations. Because most CFD codes use parallelization techniques based on Message Passing, a so called MIMD Object Abstraction is described in order to abstract the parallel computation threads to a single CORBA conform instance. The main goal for ...

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A system and method for generating global asynchronous signals in a computing structure. Particularly, a global interrupt and barrier network is implemented that implements logic for generating global interrupt and barrier signals for controlling global asynchronous operations performed by processing elements at selected processing nodes of a computing structure in accordance with a processing algorithm; and includes the physical interconnecting of the processing nodes for communicating the global interrupt and barrier signals to the elements via low-latency paths. The global asynchronous signals respectively initiate interrupt and barrier operations at the processing nodes at times selected for optimizing performance of the processing algorithms. In one embodiment, the global interrupt and barrier network is implemented in a scalable, massively parallel supercomputing device structure comprising a plurality of processing nodes interconnected by multiple ...

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The influences of compressive stress on the dielectric properties of (1 - x)Pb(In{sub 1/2}Nb{sub 1/2})O{sub 3}-xPbTiO{sub 3} (x = 0.1-0.5) ceramics was investigated in this study. The dielectric properties were measured under compressive stress applied parallel and perpendicular to electric field. The results clearly showed that the superimposed compression stress had pronounced effects on the dielectric properties of PIN-PT ceramics. In general, with increasing compressive stress the dielectric constant of the ceramics increased and decreased when the stress was applied parallel and perpendicular, respectively, to the electric field direction. The dielectric loss tangent, however, decreased in both stress cases. The observations were mainly interpreted in terms of competing influences of the domain switching through non-180 deg. domain walls, clamping of domain walls, de-ageing and the stress-induced decrease in the switchable part of ...

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This statement summarizes Lawrence Livermore National Laboratory`s committment to making important scientific, technological, and business contributions to global sustainability. The quest has many aspects, some socio-political or economic and some technological, and some in which the soft and hard sciences become indistinguishable, as in visionary national strategies, like Holland`s, and futuristic regional and city development plans, like those of Kagoshima and Chattanooga.

International Nuclear Information System (INIS)

This is a progress report from the Health and Safety Research Division of Oak Ridge National Laboratory. Information is presented in the following sections: Assessment Technology, Biological and Radiation Physics, Chemical Physics, Biomedical and Environmental Information Analysis, Risk Analysis, Center for Risk Management, Associate Laboratories for Excellence in Radiation Technology (ALERT), and Contributions to National and Lead Laboratory Programs and Assignments--Environmental Restoration.

International Nuclear Information System (INIS)

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

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Thrust faulting, folding, and penetrative compressional fabrics (e.g. spaced cleavage, pencils, and coal cleats) have been found in several outcrops within the central Deep River Basin (the southern Durham subbasin to the northern Wadesboro subbasin). The trend of these structures is nearly parallel to the basin, and may locally control the present geometry of the basin boundaries. These features are distributed throughout the stratigraphic section and across the entire width of the basin. In outcrops where relative timing can be determined, the compressional structures post-date all extensional and intrusive features associated with basin formation. In particular, thrusts cut across and displace basin-parallel normal faults and basin-normal cross-faults. All thrusts found to date verge northwest, and displacements of cross-fault boundaries indicate that transport was approximately 325[degree].

Energy Technology Data Exchange (ETDEWEB)

After cooling ceilings and source ventilation, simple air conditioning systems like thermal activation of concrete cores are gaining general acceptance. Parallel to this, ground source cooling systems are reducing the need for cold generation. Air conditioning systems of this type are favoured by producers of floor heating systems looking for a new market segment. [German] Nach Kuehldecken und Quellueftung gewinnen jetzt einfach aufgebaute Raumklimaanlagen, wie die thermische Betonkernaktivierung, immer mehr Anhaenger. Parallel dazu werden Verfahren zur Erdkaeltenutzung entwickelt, die den Anteil kuenstlich erzeugter Kaelte weiter zurueckdraengen. Forciert wird diese Art der Klimatisierung insbesondere durch die Hersteller von Fussbodenheizungen, fuer die sich hier ein neues Marktsegment eroeffnet. (orig.)

British Library Electronic Table of Contents (United Kingdom)

The efficient design of computation intensive multidimensional signal processing applications requires dealing with three kinds of constraints: those implied by the data dependencies, the non-functional requirements (real-time, power consumption) and resources availability of the execution platform. Modeling and Analysis of Real-time and Embedded systems (MARTE) UML profile through its repetitive structure modeling (RSM) package is well suited to model the inherent parallelism within these applications, a compact representation of parallel execution platforms and the distributive mapping of one on another. The execution of such a specification respects the whole set of constraints defined upon, while the quality of the scheduling is directly linked to the quality of the mapping of the mult...

British Library Electronic Table of Contents (United Kingdom)

Multiple receivers can be utilized to enhance the spatiotemporal resolution of MRI by employing the parallel imaging technique. Previously, we have reported the L-curve Tikhonov regularization technique to mitigate noise amplification resulting from the geometrical correlations between channels in a coil array. Nevertheless, one major disadvantage of regularized image reconstruction is lengthy computational time in regularization parameter estimation. At a fixed noise level, L-curve regularization parameter estimation was also found not to be robust across repetitive measurements, particularly for low signal-to-noise ratio (SNR) acquisitions. Here we report a computationally efficient and robust method to estimate the regularization parameter by partitioning the variance of the noise-white...

Energy Technology Data Exchange (ETDEWEB)

During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

CERN Document Server

We present first worldline numerical results for the nontrivial interplay between geometry and temperature dependencies of the Casimir effect. We show that the temperature dependence of the Casimir force can be significantly larger for open geometries (e.g., perpendicular plates) than for closed geometries (e.g., parallel plates). For surface separations in the experimentally relevant range, the thermal correction for the perpendicular-plates configuration exhibits a stronger parameter dependence and exceeds that for parallel plates by more than an order of magnitude at room temperature. This effect can be attributed to the fact that the fluctuation spectrum for closed geometries is gapped, inhibiting the thermal excitation of modes at low temperatures. By contrast, open geometries support a thermal excitation of the low-lying modes in the gapless spectrum already at low temperatures.