Uranium dendrites which were deposited at a solid cathode of an electrorefiner contained a certain amount of salts. These salts should be removed for the recovery of pure metal using a cathode processor. In the uranium deposits from the electrorefining process, there are actinide chlorides and rare earth chlorides in addition to uranium chloride in the LiCl-KCl eutectic salt. The evaporation behaviors of the actinides and rare earth chlorides in the salts should be investigated for the removal of salts in the deposits. Experiments on the salt evaporation of rare earth chlorides in a LiCl-KCl eutectic salt were carried out. Though the vapor pressures of the rare earth chlorides were lower than those of the LiCl and KCl, the rare earth chlorides were co-evaporized with the LiCl-KCl ...
One of the concerns with locating radioactive waste storage sites in saltdeposits is how to permanently seal the underground storage areas once they have reached their storage capacity. The compaction of salt using explosives has been identified as a potential method of producing permanent seals in both entryways and shafts to storage areas. This paper describes the test procedure and results of a preliminary investigation to determine the feasibility of utilizing explosives in the compaction of salt. Three simple tests were carried out to measure the degree to which loose salt could be compacted.
Objective of the project is characterization of electrode reactions in molten salt by using metal oxides and silica-based electrode. The scope of project are characterization of metal oxide properties in molten salt and miniaturization of 3-electrode electrochemical test cell. Electrochemical micro-cell for actinide-LiCl-KCl molten salt was newly designed. Electroless and electrochemical deposition technique was applied to Mo coating on quartz tube. From the design of electrode and 3-electrode electrochemical cell suitable for the tests in molten salt electrolyte, so it is anticipated to get the information on the electrochemical behavior of metallic electrode in molten salt and to secure the information on oxidation/reduction behavior of actinide
Effects of ions of Group IA, IIA, IIIB, and VIIB elements on the cathodic deposition of a molybdenum were investigated in a KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt at 773 K (500/degree/C). The results can be summarized as follows: The addition of potassium, rubidium, cesium, and barium cations and fluorine anions to the KCl-LiCl (eutectic)-MoCl/sub 3/ molten salt is effective in depressing the cathodic deposition of the molybdenum subchloride, which hinders the smooth, flat electrodeposition of molybdenum. The addition of lithium, sodium, magnesium, calcium, strontium, and aluminum cations and bromine and iodine anions promotes the undesirable cathodic deposition of the molybdenum subchloride.
The patent is for a method of preparing drilling muds that are notable for their chemical resistance to Zechstein deposits, especially to magnesium, carbonate and carboxylic acid ions. To achieve chemical resistance of the drilling mud to Zechstein deposits, it is suggested to saturate them with salt (the amount of added salt depends on the absorption properties of the solution), and then to process them with caustic soda or potassium oxide hydrate and lime in proportions that would cause filtrate alkalinity not to exceed 0.5. For example, to prepare drilling solution to bore through mediums containing magnesium salts, potassium salts, rock salt, anhydrate, dolomite, limestone, red salt clay: add 340 kg potassium chloride into 1 m/sup 3/ drilling solution with weighed bentonic clay, 10 kg. ferro-chromate lignosulfite, 7 ...
The addition of carbon to samples, during imaging, presents a barrier to accurate TEM analysis, the controlled deposition of hydrocarbons by a focused electron beam can be a useful technique for local nanometer-scale sculpting of material. Here we use hydrocarbon deposition to form nanopores from larger focused ion beam (FIB) holes in silicon nitride membranes. Using this method, we close 100-200nm diameter holes to diameters of 10nm and below, with deposition rates of 0.6nm per minute. I-V characteristics of electrolytic flow through these nanopores agree quantitatively with a one dimensional model at all examined salt concentrations.
The Eagle Flat basin, an intermontane basin in Trans-Pecos Texas, is being considered as a possible site for the Texas repository of low-level radioactive wastes. Intermontane basins and associated normal faults formed in response to Basin and Range tectonism that began about 24 Ma ago. The most active late Tertiary and Quaternary faults occur within the Hueco Bolson (HB) and the Salt Basin/Salt Flat/Lobo Valley, west and east, respectively, of the proposed repository. Several faults of the southeast HB which are within 50 km of the site, displace middle Pleistocene deposits 10 to 24 m. The most recent surface rupture in the southeast HB probably occurred on the Amargosa fault during the Holocene. Upper Pleistocene deposits are offset 2.5 to 4.5 m, and middle Pleistocene deposits are displaced 24 m. Fault scarps within 50 km east of the proposed repository are associated with faults ...
Alpha continuous air monitors (CAMs) will be used at the Waste Isolation Pilot Plant (WIPP) to measure airborne transuranic radioactivity that might be present in air exhaust or in work-place areas. WIPP CAMs are important to health and safety because they are used to alert workers to airborne radioactivity, to actuate air-effluent filtration systems, and to detect airborne radioactivity so that the radioactivity can be confined in a limited area. In 1993, the Environmental Evaluation Group (EEG) reported that CAM operational performance was affected by salt aerosol, and subsequently, the WIPP CAM design and usage were modified. In this report, operational data and current theories on aerosol collection were reviewed to determine CAM quantitative performance limitations. Since 1993, the overall CAM performance appears to have improved, but anomalous alpha spectra are present when sampling-filter saltdeposits are at normal ...
Until 1990, in Tuscany, salt pollution of anti-salt insulators installed on high-tension transmission lines had led to rare breakdowns. On the contrary, in the last months of 1990, in most of Tuscany, following a strong libeccio wind coming from the Tyrrhenian Sea, and due to a long period of drought, saltdeposits accumulated on the insulators of the high-voltage transmission lines (380 kV, 220 kV and 132 kV). This phenomenon not only took place in the coastal areas near Livorno, Pisa and Grosseto, but also in areas far away from the sea such as Florence, Prato, Arezzo and Siena. Following this, several high-tension lines, and whole sections of 380 kV electric stations went out of order, damaging the stations' equipment, insulators on the lines, and in particular porcelain insulators. The maintenance operations that were immediately undertaken consisted in washing operations, first focussed on ...
Until 1990, in Tuscany, salt pollution of anti-salt insulators installed on high-tension transmission lines had led to rare breakdowns. On the contrary, in the last months of 1990, in most of Tuscany, following a strong libeccio wind coming from the Tyrrhenian Sea, and due to a long period of drought, saltdeposits accumulated on the insulators of the high-voltage transmission lines (380 kV, 220 kV and 132 kV). This phenomenon not only took place in the coastal areas near Livorno, Pisa and Grosseto, but also in areas far away from the sea such as Florence, Prato, Arezzo and Siena. Following this, several high-tension lines, and whole sections of 380 kV electric stations went out of order, damaging the stations' equipment, insulators on the lines, and in particular porcelain insulators. The maintenance operations that were immediately undertaken consisted in washing operations, first focussed on ...
In PWR steam-generators, the crevice between tube and tube-support plate tends to fill with porous deposits during operation and acts as a concentration site for chemicals in the boiler water, which may lead to corrosion of the tube and tube-support-plate. The rate of concentration, the magnitude of the concentration factor and the rate of release of solute when conditions change are important parameters for devising strategies to minimize corrosion. Values of these parameters for salt concentration have therefore been measured in a laboratory simulation of the crevice and are used to formulate a model of the concentrating process.
Corrosion behavior of deposition coated specimens prepared by the technique proposed by the authors is investigated in salt immersion tests, and also those of pure magnesium, 3N, 4N and 6N grades, and magnesium alloys, AZ31 and AZ91E, are investigated for comparison. Inhomogeneous corrosion occurs in AZ31 and AZ91E alloys when buffered solutions with pH values of 6.5 and 9.0 including 1% NaCl and a conventional 3% NaCl solution are used for immersion tests, while 6N-Mg shows homogeneous corrosion in such solutions. Corrosion behavior of the deposition coated specimen resembles that of 6N-Mg. Purification process included in the deposition coating technique provides homogeneity in microstructural and electrochemical terms, which results in improving corrosion resistance. (orig.)
A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500 deg. C. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12 wt.% Li and only 0.264 wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.
A body-centered cubic (bcc) Mg-12Li-9Al-1Zn (wt.%) alloy was fabricated in air by electrolysis from LiCl-KCl molten salt at 500degreeC. Electrolytic deposition of Li atoms on cathode (Mg-Al-Zn alloy) and diffusion of the Li atoms formed the bcc Mg-Li-Al-Zn alloy with 12wt.% Li and only 0.264wt.% K. Low K concentration in the bcc Mg alloy strip after the electrolysis process resulted from 47% atomic size misfit between K and Mg atoms and low solubility of K in Mg matrix.
A study of more than 1200 of 72-fold, migrated, seismic reflection profiles, from the eastern part of the East Breaks flexure trend, Gulf of Mexico, indicates that, although individual seismic reflectors cannot be traced across the entire area, seismic depositional units can be recognized and correlated from basin to basin in most instances. Three tentative conclusions are evident from this study: (1) salt diapirs appear to have grown through a series of intermittent movements to form structurally separate intraslope basins; (2) sedimentation is probably channeled by differential dome growth, which creates local stratigraphic differences between basins; and (3) packages of distinctive seismic depositional units can be successfully used to map sediment cycles between separate basins. Fluctuations of Pleistocene sea level appears to be the dominate depositional control on the upper continental slope in ...
Results are reported from initial characterization tests on the environmental effects of the natural draft cooling tower of the Chalk Point Unit 3 oil-fired power plant located on the shore of Chesapeake Bay. Data are included on updraft air velocity, plume drift, and sea saltdeposition in relation to meteorological conditions.
Metal nanoparticles have many potential technological applications. Biological routes to the synthesis of these particles have been proposed including production by vascular plants, known as phytoextraction. While many studies have looked at metal uptake by plants, particularly with regard to phytoremediation and hyperaccumulation, few have distinguished between metal deposition and metal salt accumulation. This work describes the uptake of AgNO{sub 3}, Na{sub 3}Ag(S{sub 2}O{sub 3}){sub 2}, and Ag(NH{sub 3}){sub 2}NO{sub 3} solutions by hydroponically grown Brassica juncea and the quantitative measurement of the conversion of these salts to silver metal nanoparticles. Using X-ray absorption near edge spectroscopy (XANES) to determine the metal speciation within the plants, combined with atomic absorption spectroscopy (AAS) for total Ag, the quantity of reduction of Ag{sup I} to Ag{sup 0} is reported. Transmission electron ...
In the Assel'skiy and Sakmarskiy time of the lower Permian epoch, on the territory of the modern Dnieper and Donets, and Pripyatskiy Basins, there was a gulf which stretched in a northwest direction. The latter connected to the open sea in the east through the CisDonets trough. Transverse tectonic elevations divided the gulf into 5 semi-isolated reservoirs. In the Assel'skiy time, in the period of carbonate sedimentation, the development of algae, crinoids, corals and other organisms occurred. They created reef, bioherm and biostroma reconstructions. The most favorable sections for their settlement were the coastal zones of the gulf, consedimentation positive structures and transverse tectonic elevations. It is assumed that the formation of reefs, bioherms and biostromas, on the one hand, and sedimentation of evaporites on the other hand, are interrelated processes. The first after the next marine transgression during their growth was a greater impairment to the water ...
Cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were employed to investigate the electrodeposition of Eu and Al in an LiCl-KCl eutectic melt containing Eu{sup 2+} and Al{sup 3+} at 450 deg. C. In order to deposit a pure Eu and Al alloy, the stoichiometrically lower concentration of Al{sup 3+} than that of Eu{sup 2+} and Al wires as a counter electrode was introduced into the bath of LiCl-KCl melt for the electrodeposition. The electrodeposition takes place at a potential more negative than -1.95 V vs. Ag|Ag{sup +} while the deposit is oxidized at more positive potential than -1.92 V. Two new reduction peaks and an anodic peak on a W working electrode were observed at -2.39 V, -2.42 V, and -2.1 V, vs. Ag|Ag{sup +}, respectively, suggesting that the potential window of the Al system in LiCl-KCl melt can be extended to -2.43 V vs. Ag|Ag{sup +}. The EDS analysis indicated that AlEu can be ...
Cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) were employed to investigate the electrodeposition of Eu and Al in an LiCl-KCl eutectic melt containing Eu2+ and Al3+ at 450 deg. C. In order to deposit a pure Eu and Al alloy, the stoichiometrically lower concentration of Al3+ than that of Eu2+ and Al wires as a counter electrode was introduced into the bath of LiCl-KCl melt for the electrodeposition. The electrodeposition takes place at a potential more negative than -1.95 V vs. Ag|Ag+ while the deposit is oxidized at more positive potential than -1.92 V. Two new reduction peaks and an anodic peak on a W working electrode were observed at -2.39 V, -2.42 V, and -2.1 V, vs. Ag|Ag+, respectively, suggesting that the potential window of the Al system in LiCl-KCl melt can be extended to -2.43 V vs. Ag|Ag+. The EDS analysis indicated that AlEu can be deposited at the potential ...
The lower continental slope of the northwestern Gulf of Mexico is characterized by a hummocky topography with shallow salt masses interspersed by numerous salt-withdrawal basins containing thick Plio-Pleistocene and older sediments. Analysis of over 7500 km of multichannel seismic reflection data from the Keathley Canyon Area and vicinity defined the Wisconsinan-Holocene sequence and its seismic facies. In interbasinal areas and in the southern part of the study area where salt is shallow, the Wisconsinan-Holocene sequence consists mainly of low-amplitude (LA) facies underlain by strong basal-reflection (SBR) facies. The LA facies occasionally show subtle onlaps against SBR facies and grade upward into a draping pattern. Onlapping LA facies are interpreted to be a lowstand systems tract deposited by widespread low-energy turbidity currents. Draping LA facies at the top may consist of hemipelagic or ...
Over the past 40 years, cavern storage of LPG's, petrochemicals, such as ethylene and propylene, and other petroleum products has increased dramatically. In 1991, the Gas Processors Association (GPA) lists the total U.S. underground storage capacity for LPG's and related products of approximately 519 million barrels (82.5 million cubic meters) in 1,122 separate caverns. Of this total, 70 are hard rock caverns and the remaining 1,052 are caverns in saltdeposits. However, along the eastern seaboard of the U.S. and the Pacific northwest, saltdeposits are not available and therefore, storage in hard rocks is required. Limited demand and high cost has prevented the construction of hard rock caverns in this country for a number of years. The storage of natural gas in mined caverns may prove technically feasible if the geology of the targeted market area is suitable; and economically ...
Experimental investigations have been shown that the thermal stability of carnallite shows a clear change to hogher temperature with increasing pressure if the decomposition atmosphere is not removed. Around 40 bar, constitutional water is released from the carnallite lattice at 139/sup 0/C, around 100 bar at 145/sup 0/C. The available temeprature data on thermal release of constitutional water in carnallite (80 to 110/sup 0/C) are not relevant to the possible heat load in a final-storage salt done as all investigations have been carried out in vacuum or in open systems under atmospheric conditions. The author's investigations show the decomposition temeprature of carnallite will be much higher under in-situ conditions with blocked or delayed removal of decomposition atmosphere. However, this applies only to carnallite as isolated mineral phase. Final statements cannot be made until the pressure-temperature stability of carnallite in paragenesis with ...
Spent oxide fuels are reduced in a molten salt of CaCl[sub 2]-CaF[sub 2] to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing uranium and long time management for uranium. ...
Spent oxide fuels are reduced in a molten salt of CaCl_2-CaF_2 to convert them into metals, then melted in an Fe-U bath disposed in an electrolytic refining vessel and brought into contact with molten Mg, to extract transuranium elements and rare earth elements contained in the Fe-U bath as metals in the molten Mg. Then molten Mg is removed and the residue is brought into contact with KCl-LiCl molten salt and electrolyzed using the Fe-U as an anode. Then, uranium is recovered by deposition on an iron cathode disposed in chloride electrolytes of the electrolytic refining vessel. Uranium and transuranium elements can be thus separated and, for example, depleted uranium for use in blanket fuels can be recovered easily. This can greatly reduce the temporary storage amount of depleted uranium, to eliminate requirement for a large-scaled facility used exclusively for storing uranium and long time management for uranium. (T.M.).
Within the Williston basin, thickness variations of the Prairie Formation are common and are interpreted to originate by two processes: differential accumulation of salt during deposition and differential removal of salt by dissolution. Unambiguous evidence for each process is rare because the Prairie/Winnipegosis interval is seldom cored within the US portion of the basin. Therefore, indirect methods, using well logs, provide the principal method for identifying characteristics of the two processes. The results of this study indicate that the two processes can be distinguished using correlations within the Prairie Formation. Several regionally correlative brining-upward and probably shoaling-upward sequences occur within the Prairie Formation. Near the basin center, the lowermost sequence is transitional with the underlying Winnipegosis Formation. This transition is characterized by thinly laminated basal carbonates that ...
The electrochemical behavior of Sb(III) ions was investigated in LiCl-KCl molten salt at 673K. The reaction mechanism and transport parameters of electroactive species were determined by transient electrochemical techniques (such as cyclic voltammetry, square wave voltammetry, chronopotentiometry and chronoamperometry) at a molybdenum electrode. The results showed that electrochemical reduction of Sb(III) in LiCl-KCl melts occurred in a reaction step with an exchange of three electrons. A voltammogram with a different scan rate in LiCl-KCl containing 1.45x10^-^4molcm^-^3 SbCl3 showed that the deposition/dissolution reaction of Sb(III) ions was not completely reversible. The diffusion coefficient of Sb(III) ions was 1.65(+/-0.01)x10^-^5cm^-^2s^-^1 at 673K. The electroreduction of Sb(III) io...
A drift dye tracer experiment, using Rhodamine (WT) dye, was conducted on airborne drift from a natural draft cooling tower at PEPCO's Chalk Point, Maryland Power Generating Station. This experiment was designed to separate and identify cooling tower aerosol deposition from other sources and to provide a data base for use in cooling tower salt loading and model validation. Prior to the experiment, laboratory tests showed that Rhodamine (WT) was inexpensive, safe and controllable when used as a drift dye tracer. Positive identification and separation of cooling tower drift can be made among other sources using a dye tracer.
Field corrosion tests were conducted on eight single tube materials and two welded overlay materials in three typical Japanese waste incineration plants in an effort to develop new corrosion-resistant superheater tubes capable of functioning efficiently under temperature and pressure conditions of 500 C and 100 kgf/cm{sup 2}-g in high-efficiency waste-to-energy (WTE) plants. Austenitic alloys containing higher concentrations of chromium, nickel, and molybdenum [Cr + Ni + Mo] showed excellent corrosion-resistant properties, and the new alloys JHN24 and HR30M showed good corrosion resistance. Different corrosion rates found in each of the three plants were explained by differences in operating conditions, such as gas temperature, concentration of molten salts resulting from chlorine (Cl) content of deposits, heavy metal (zinc oxide [ZnO] + lead oxide [PbO]) content, etc. It was confirmed that the corrosion rate of materials positioned in the ...
45{number_sign} steel, which has good mechanical strength and is relatively cheap, is a common constituent in industrial components, such as precision gears, piston columns of oil pumps, and so on. However, since the working environment of these industrial parts is sometimes quite harsh and unforgiving, they are vulnerable to wear and corrosion. Replacing 45{number_sign} steel with stainless or alloy steel increases the cost significant, and a better alternative is to improve its surface properties and lifetime using plasma immersion ion implantation (PIII). The authors have devised a variety of treatment processes using PIII, including radio-frequency (RF) plasma nitriding, RF plasma nitriding and nitrogen PIII, Ti deposition in conjunction with nitrogen PIII (IBED), as well as Cr deposition followed by nitrogen PIII (IBED). To assess the efficacy of the processes, the microhardness and mass loss due to wear were measured for both the ...
The first sediments to onlap the metamorphosed Precambrian Arabian shield were Infracambrian (Proterozoic) to Middle Cambrian carbonates, clastics, and evaporites. The oldest Arabian reservoir rocks occur in the Precambrian to lower Paleozoic Era Salt of the Huqf Group, which forms the Birba field of Oman. The Middle Cambrian sequence was followed by Late Cambrian through Early Permian marine sandstones and continental to littoral siltstones and variegated shales. The first commercial oil discovered in the Arabian Gulf region occurs in fluvial sands of the Ordovician to Permian Haima and Haushi Groups of the Marmul field in south Oman. These strata are also productive in other fields and are sealed by unconformable contact with the Al Khlata Formation or beneath shale of the Albian Nahr Umr Formation. The deeply buried kerogen sediments of the Huqf Group to the southeast are believed to be the source rocks for these fields of south Oman. The Late Permian to ...
BackgroundGlycochenodeoxycholate (GCDA) is one of the major human bile salts. Bile salts stimulate cell survival and proliferation through the mitogen-activated protein kinase, but...Full Text Available
Plantago media L. and Plantago maritima L. differ in their strategy toward salt stress, a major difference being the uptake and distribution of ions. Patch clamp techniques...Full Text Available
Production of Fe_2O_3, Y_2O_3, YFeO_3, Y_3Fe_5O_1_2 powders using the alkoxomethod - during hydrolysis by yttrium and iron alcohol solutions, is studied. It is stated that production of the powders of Y_2O_3-Fe_2O_3 system oxides using alkoxomethod permits to decrease essentially the reaction volumes, number of operations, their duration as compared to the cooxidation of oxide hydrates from inorganic salt aqueous solutions. During heat treatment of iron (3) alcohol hydrolysis products #gamma#-Fe_2O_3 is first crystallized by contrast to #alpha#-FeOOH, usually produced by deposition from solutions. Further heat treatment of #gamma#-Fe_2O_3 results in production of #alpha#-Fe_2O_3. Conditions for crystallization of Y_3Fe_5O_1_2 and YFeO_3 phases, prepared by both methods, and their crystallite mean sizes are close, but the powders obtained from alcohols are more homogeneous.
An automated Time Resolved Aerosol Collector (TRAC) has been developed for sequential sampling of field-collected aerosols for laboratory-based Computer Controlled Scanning Electron Microscopy/Energy Dispersed X-ray (CCSEM/EDX) single particle analysis. The collector is optimized for use of grid-supported 20 nm carbon films as deposition substrates. The carbon films have low enough X-ray background to permit EDX analysis down to 0.1-0.2 ?m particles, including detection of low-Z elements: C, N, & O. The TRAC provides unattended sampling onto a set of 151 individual grids, at sequential time intervals as short as 1 min. After collection, the samples are sealed and refrigerated pending analysis. The utility of the TRAC-CCSEM/EDX approach is exemplified using the aerosol samples collected during the Texas 2000 Air Quality Studies (Aug. 15 ? Sept. 15, 2000). We are able to quantitatively follow the time evolution in the relative contribution of non-volatile ...
This article discussed a project formed to develop innovative seismic imaging technologies. The Kaleidoscope project aims to accelerate the processing of seismic sound waves by several orders of magnitude using advanced computer-based techniques to reveal oil and gas deposits buried deep in the earth in a manner that is both cost-effective and efficient. It is expected that the technology will be used in deep water applications with massive untapped reserves. The seismic technology will be used to locate hydrocarbons and oil reserves buried 20,000 feet beneath the seabed. It is estimated that the Gulf of Mexico contains 56 billion barrels of oil equivalent worth nearly $6 trillion. However, the reserves are difficult to locate due to the interbedded salt bodies in the subsurface. The project is simultaneously working on both hardware and software applications, and are currently writing the first petascale set of seismic imaging applications. ...
We demonstrate a preparative method which produces highly-monodisperse Pt-nanoparticles of tunable size without the external addition of seed particles. Hexachloroplatinic acid is dosed slowly to an ethylene glycol solution at 120 C and reduced in the presence of a stabilizing polymer poly-N-vinylpyrollidone (PVP). Slow addition of the Pt-salt first will first lead to the formation of nuclei (seeds) which then grow further to produce larger particles of any desired size between 3 and 8nm. The amount of added hexachloroplatinic acid precursor controls the size of the final nanoparticle product. TEM was used to determine size and morphology and to confirm the crystalline nature of the nanoparticles. Good reproducibility of the technique was demonstrated. Above 7nm, the particle shape and morphology changes suddenly indicating a change in the deposition selectivity of the Pt-precursor from (100) towards (111) crystal faces and breaking up of ...
This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate the effect of ionic concentrating due to elevated temperature water flowing through fractures where salts and minerals have been deposited due to evaporation and boiling.
This paper indicates first that the base content in desert soil is by far much higher than that in soils in moist areas, that salts with the higher solubility to water have their deposition depth greater, and that the organic content is extremely low. The paper also describes the experiments to verify that the desert soil contains soil lumps with a diameter of about several millimeters, which function effectively to form the long term survival locations for microorganisms. Desert soil containing soil lumps and the one removed of lumps by pulverizing them into powder were prepared as test specimens, which were left submerged. It was confirmed that the velocity of decomposing the organics and the mechanical strength in the latter soil are obviously inferior to those in the former soil. Additional remarks are given that when the desert soil environment is changed the microorganisms get more active appreciably and that certain kinds of mold fungi ...
For heavy-ion beam driven inertial fusion ''liquid-protected'' reactor designs such as HYLIFE-II, a mixture of molten salts made of F{sup 10}, Li{sup -6}, Li{sup 7} and Be{sup 9} (called flibe) allows small chambers and final-focus magnets closer to the target with superconducting coils suffering higher radiation damage, though they can stand only a certain amount of energy deposited before quenching. This work has been primarily focusing on verifying that total energy deposited by fusion neutrons and induced gamma rays remain under such limit values and the final purpose is the optimization of the shielding of the magnetic lens system from the points of view of the geometrical configuration and of the physical nature of the materials adopted. The system is analyzed in terms of six geometrical models going from simplified up to much more realistic representations of a system of 192 beam ...
Author.Field, laboratory and market studies are a must for proper evaluation of natural resources for the mineral industry of lebanon. Sites selectively convenient to the existing major Lebanese ceramics industry centered in the Beqa'a region, were investigated as to their geology, geography and economic character. The raw materials are shales, mud stones, siltstones and other argillaceous rocks of Jurassic to Cretaceous age coming from selective sites in south and central Lebanon. The finished products include wall, floor, roofing tiles, pipes, sanitary ware, pottery and brick specimens. Differential thermal analysis, scanning electron microscopy, firing and physico-chemical tests and analyses characterized the raw materials into two major groups: the suitable are siliceous argillaceous rocks and unsuitable calcareous argillaceous rocks. The suitable group is divided into two varieties. The first is dominantly a disordered Kaolinite with low drying and firing values, low plasticity ...
Numerous bacteria from a salt-marsh environment are capable of degrading malathion, an organophosphate insecticide, when supplied with additional nutrients as energy and carbon sources. Seven isolates...Full Text Available
In the first part of this paper, IrO_2 electrodes produced by thermal decomposition of H_2IrCl_6 precursor were manufactured using the spin coating deposition technique, where centrifugal forces spread the precursor solution with simultaneous evaporation of the solvent on the rotating Ti substrate. It was found using this technique, that it is possible to obtain thin and uniform IrO_2 coatings with controlled loadings. The influence of the concentration of iridium salt in the precursor solution (c_0) as well as the influence of the rotation speed at which the substrate spins (#omega#) on the IrO_2 loading have been studied using voltammetric charge measurements. From these results, a simple relation has been proposed for the estimation of the IrO_2 loading for a given c_0 and #omega#. In the second part of this paper and from measurements performed using different IrO_2 loadings and formic acid concentrations, the kinetic parameters of the ...
In order to develop new corrosion resistant superheater tubes capable of functioning efficiency under temperature and pressure conditions of 500 C and 100 ata used in high efficient waste-to-energy (WTE) plants, field corrosion tests were conducted on eight single tube materials and two welded overlay materials at metal temperatures of 450 C and 550 C for 700 and 3,000 hours, respectively, in three typical japanese waste incineration plants. The test results indicate that austenitic alloys containing higher concentrations of [Cr + Ni + Mo] show excellent corrosion resistant properties and new alloys of JHN24 and HR30M have good corrosion resistance. The different corrosion rate found for each of the three plants could be explained by differences in the severity of corrosion factors, such as, gas temperature, concentration of molten salts due to Cl content of deposits, and heavy metal [ZnO + PbO] content etc. It was also confirmed that the ...
The physical, chemical and mechanical properties of magnesium alloys make them attractive materials for automotive and aerospace applications. However, these materials are susceptible to corrosion and wear. This work discusses the potential of using sol-gel based coatings consisting of ZrO_2 and 15 wt.% of CeO_2. The CeO_2 component provides enhanced corrosion protection, while ZrO_2 impart corrosion as well as wear resistance. Coating deposition was performed by the dip coating technique on two magnesium alloy substrates with different surface finishes: AZ91D (as-casted, sand-blasted, and machined) and AZ31 (rolled and machined). All as-deposited coatings (xerogel coatings) were then subjected to 10 h annealing: a temperature of 180 C was applied to the AZ91D alloy and 140 C to the AZ31 alloy. Morphological and structural properties of the annealed coatings were investigated by scanning electron microscopy, atomic force microscopy and ...
Development of the engineering technology basis of pyrometallurgical reprocessing is a key issue for industrialization. For development of the transport technologies of molten salt and liquid cadmium at around 773 K, a salt transport test rig and a metal transport test rig were newly installed in an Ar glove box. Function of the salt transport test rig was confirmed with LiCl-KCl molten salt, and the transport behaviour of molten salt was found to follow that of water. The molten salt/liquid metal contactor for Ln/An separation was newly designed and installed. The test with a single-stage contactor was successful with simulated elements, and a three-stage contactor is now under development. A large-scale electro-refiner with a function to transport molten salt and liquid cadmium were newly designed, and to be installed for demonstration ...
Metastable yttrium-oxide films are synthesized using reactive sputter deposition. The yttrium concentration of the as-deposited film is found to vary as a function of the sputter deposition rate. In addition to the synthesis of the cubic equilibrium phase...
Recently the authors showed that tetrazolium salts can be obtained during the oxidation of substituted 1,3,5-triarylformazans with potassium permanganate in a two-phase organic solvent-water system. The role of phase-transfer catalyst in this reaction is played by the tetrazolium salt, which is formed in a small amount as the result of oxidation of the formazan at the phase boundary. The method is distinguished by its extreme simplicity. However, the yield of the tetrazolium salts fluctuates within wide limits and does not exceed 62%. This is due to the fact that as the reaction proceeds the pH of the aqueous phase increases from 6 to 12. At the same time it is known that tetrazolium salts are unstable in aqueous alkaline solutions. They found that if the aqueous phase is replaced by aqueous hydrochloric acid (5 wt. %) the yields of the tetrazolium salts (Ia-g) are increased to ...
The phase separation of (water + salt + polyethylene glycol 15000) systems was studied by cloud-point measurements using the particle counting method. The effect of three kinds of sulphate salt (Na2SO4, K2SO4, (NH4)2SO4) concentration, polyethylene glycol 15000 concentration, mass ratio of polymer to salt on the cloud-point temperature of these systems have been investigated. The results obtained indicate that the cloud-point temperatures decrease linearly with increase in polyethylene glycol concentrations for different salts. Also, the cloud points decrease with an increase in mass ratio of salt to polymer.
The purpose of the conversion process is to convert the {sup 233}U fluoride compounds that are being extracted from the Molten Salt Reactor Experiment (MSRE) equipment to a stable oxide for long-term storage at Bldg. 3019.
The sequence information available for homeodomains reveals that salt bridges connecting pairs 19/30, 31/42, and 17/52 are frequent, whereas aliphatic residues at these sites are rare and mainly restricted...Full Text Available
The conformation of the self-complimentary DNA dodecamer d(br5CGbr5CGAATTbr5CGbr5CG) has been investigated in a variety of salt and solvent conditions by one and two-dimensional 1H NMR. In low salt...Full Text Available
Artifacts in two-dimensional electrophoresis (2-DE) caused by the presence of salts in isoelectric focusing (IEF) have been previously described as a result of increasing conductivity and inducing electroosmosis....Full Text Available
The effect of associative interactions of monomers and propagating macroradicals in homopolymerization of N-[3-(dimethylamino)propyl]methacrylamide salts and their copolymerization with acrylonitrile and acrylamide in aqueous solution was studied.
Cited are the results of physico-chemical studies and industrial tests of a copolymer of methacrylic acid and diethylammonium salt, used for limiting the influx of stratum waters into a well.
The constitutive model used to describe the deformation of crushed salt is presented in this report. Two mechanisms -- dislocation creep and grain boundary diffusional pressure solution -- are combined to form the basis for the constitutive model governing the deformation of crushed salt. The constitutive model is generalized to represent three-dimensional states of stress. Upon complete consolidation, the crushed-salt model reproduces the Multimechanism Deformation (M-D) model typically used for the Waste Isolation Pilot Plant (WIPP) host geological formation salt. New shear consolidation tests are combined with an existing database that includes hydrostatic consolidation and shear consolidation tests conducted on WIPP and southeastern New Mexico salt. Nonlinear least-squares model fitting to the database produced two sets of material parameter values for the model -- one for the ...
The conformation of d (CG)n oligomers with n = 2,3 has been studied in aqueous solution in the presence of high salt concentration. A minimum n value of three is necessary to obtain a left-handed Z-helix....Full Text Available
This study examined the genetic basis of hypertension and renal disease in Dahl SS/Mcwi (Dahl Salt-Sensitive) rats using a complete chromosome substitution panel of consomic rats in which each of the...Full Text Available
Interfacial tension at the aqueous solution of di-2-ethylhexylphosphoric acid or its copper salts/water solutions has been measured by the drop volume method.
This paper advances hypotheses on the chemistry of the interaction of thorium and yttrium with organic-inorganic salts of molybdenum polyacids. On the basis of an analysis of the data of an adsorption experiment and the quantitative relationships that follow from the law of mass action, it is shown that thorium is absorbed by the solid phase by coprecipitation with the participation of complex formation, while the coprecipitation of yttrium with salts of polyacids is due to a reaction of ion exchange chemisorption.
Naval Petroleum Reserve No. 3 (NPR-3), also known as Teapot Dome, is a government-owned oil field in Natrona County, Wyoming. It is an asymmetrical anticline located on the western edge of the Powder River Basin, just south of the Salt Creek Anticline. Production started in 1922, and today the field is a marginally economic stripper field with average production of less than 3 BOPD (0.5 m{sup 3}/D) per well. Total field production is about 1,800 BOPD (286 m{sup 3}/D). The Second Wall Creek Formation was waterflooded from 1979 until June 1992 with poor results due to the extensive natural fracture system in this sandstone unit. Since water injection ceased, reservoir pressure has declined to very low levels. Liquids extraction and reinjection of the gas produced from high-GOR wells along the gas-oil contact continues, but the average gas cap pressure has fallen to approximately 150 psi (1.03 MPa) from an original pressure of 1,120 psi (7.72 MPa). Since the oil is ...
As a result of the large limestone deposits available in Poland, the low cost of reagent acquisition for the largescale technological use and relatively well-documented processes of flue gas desulfurization (FGD) technologies based on limestone sorbent slurry, wet scrubbing desulfurization is a method of choice in Poland for flue gas treatment in energy production facilities, including power plants and industrial systems. The efficiency of FGD using the above method depends on several technological and kinetic parameters, particularly on the pH value of the sorbent (i.e., ground limestone suspended in water). Consequently, many studies in Poland and abroad address the impact of various parameters on the pH value of the sorbent suspension, such as the average diameter of sorbent particles (related to the limestone pulverization degree), sorbent quality (in terms of pure calcium carbonate [CaCO3] content of the sorbent material), stoichiometric surfeit of CaCO3 in ...
The Fredericksberg of South Florida may have a great oil potential that has been overlooked as a primary target in past decades. Previous exploration in the area has targeted the Lower Cretaceous oil-producing Sunniland Formation lower in the stratigraphic section. The Fredericksberg Dollar Bay Formation has hydrocarbon shows in many wells occurring in limestone biohermal deposits as well as in an upper dolomitic section. The Dollar Bay Formation is part of the Big Cypress Group of the Comanchean Series of the Lower Cretaceous. The Lower Cretaceous lithology is composed of evaporitic-carbonate cycles consisting of anhydrites, dolomites, and limestones. There are also present some calcareous shales, mudstones, salt, lignitic material, and carbonaceous material, especially in the anhydrite and limestone intervals. The limestones are usually micritic, chalky, calcarenitic, sometimes argillaceous, containing skeletal particles of gastropods, ...
The Upper Jurassic Hith Anhydrite is a major hydrocarbon seal in the Arabian Gulf region. Outcrops, core samples from the subsurface, and the literature indicate that the Hith Formation is composed mainly of anhydrite. In most locations where a section of the Hith Formation has been measured, this unit contains less than 20% carbonate much of which is in the form of thin laminations. This lack of carbonate, locally thick layers of salt, and the predominance of anhydrite favor a playa for the setting in which this sediment was accumulated. In fact, much of the Hith has the sedimentary characteristics of the Holocene Lake MacLeod playa of Western Australia, which is dominated by layers of gypsum and halite (what little carbonate that occurs is found in layers at the base of the section). Locally the Hith appears to have accumulated in a sabkha setting, particularly toward central Abu Dhabi where it pinches out into shallow-water, and peritidal carbonate. This sabkha ...
After being pre-plated a zinc layer, an amorphous Al-Mn alloy coating was applied onto the surface of AZ31B magnesium alloy with a bath of molten salts. Then the corrosion performance of the coated magnesium alloy was examined in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the single Zn layer was active in the test solution with a high corrosion rate while the Al-Mn alloy coating could effectively protect AZ31B magnesium alloy from corrosion in the solution. The high corrosion resistance of Al-Mn alloy coating was ascribed to an intact and stable passive film formed on the coating. The performances of the passive film on Al-Mn alloy were further investigated by Mott-Schottky curve and X-ray photoelectron spectroscopy (XPS) analysis. It was confirmed that the passive film exhibited n-type semiconducting behavior in 3.5% NaCl solution with a carrier density two orders of magnitude less ...
Waste is a heterogeneous fuel, often with high levels of chlorine, alkali and heavy metals. This leads to much more severe corrosion problems than combustion of fossil fuels. The corrosion rates of the materials used can be extremely high. Materials used for heat transferring parts are usually carbon steel or low alloyed steel. These are significantly cheaper than other steels. Austenitic stainless steel is also used, but is often avoided due to its sensitivity to stress corrosion cracking. More advanced materials, such as nickel base alloys, can be used in extremely aggressive environments. Since these materials are expensive and do not always have sufficient mechanical properties, they are often used as coatings on carbon steel tubes or as composite tubes. A new method, which shows good results at the first tests in plants, is electroplating with nickel. Plastic materials can be used in low temperature parts if the temperature does not exceed 150 deg C. A glass fibre inforced ...
Atmospheric pressure plasma enhanced chemical vapour deposition system is built. The electrical and optical characteristics of the APPECVD system is given. The system is used to deposit conductive polymers and nano composites onto glass and metal surfaces. The morphological, optical, chemical and electrical characteristics of deposited surfaces are investigated using SEM, AFM four probe deposition purposes. The photovoltaic applications of plasma deposited polymers and nonconsumption are compared with deposited with electrochemical methods show different results. The electrical, chemical and morphological structures of the samples will be given.
Applications of molten salts technology to separation and synthesis of materials have been studied eagerly, which would develop new fields of materials science. Research Group for Actinides Science, Department of Materials Science, Japan Atomic Energy Research Institute (JAERI), together with Reprocessing and Recycle Technology Division, Atomic Energy Society of Japan, organized the Workshop on Molten Salts Technology and Computer Simulation at Tokai Research Establishment, JAERI on July 18, 2001. In the workshop eleven lectures were made and lively discussions were there on the fundamentals and applications of the molten salts technology that covered the structure and basic properties of molten salts, the pyrochemical reprocessing technology and the relevant computer simulation. The 10 of the presented papers are indexed individually. (J.P.N.)
Mentha pulegium L. is a medicinal and aromatic plant belonging to the Labiatae family present in the humid to the arid bioclimatic regions of Tunisia. We studied the effect of different salt concentrations on plant growth, mineral composition and antioxidant responses. Physiological and biochemical parameters were assessed in the plant organs after 2?weeks of salt treatment with 25, 50, 75 and 100?mM NaCl. Results showed that, growth was reduced even by 25?mM, and salt effect was more pronounced in shoots (leaves and stems) than in roots. This growth decrease was accompanied by a restriction in tissue hydration and K+ uptake, as well as an increase in Na+ levels in all organs. Considering the response of antioxidant enzymes to salt, leaves and roots reacted differently to saline conditions...
In the electrorefining step of the pyrochemical process, actinide ions dissolved in the LiCl-KCl eutectic salt are recovered as pure actinide metals at a cathode for a re-use as a nuclear fuel from the aspect of its nonproliferation of the nuclear fuel cycles. The lanthanide species dissolved in the LiCl-KCl eutectic salt play an important role in an effective metal purification during the electrorefining step, so it is necessary to understand the chemical and physical behaviors of lanthanides in molten salt. The in situ spectroscopic measurement system and studies according to temperature changes are essential for better understandable information. To our knowledge, the absorption studies of lanthanides at high temperatures have been reported before, but the fluorescence studies of those at high temperature are not reported yet. We will discuss here the fluorescence behaviors of lanthanides in LiCl-KCl molten ...
In the electrorefining step of the pyrochemical process, actinide ions dissolved in the LiCl-KCl eutectic salt are recovered as pure actinide metals at a cathode for a re-use as a nuclear fuel from the aspect of its nonproliferation of the nuclear fuel cycles. The lanthanide species dissolved in the LiCl-KCl eutectic salt play an important role in an effective metal purification during the electrorefining step, so it is necessary to understand the chemical and physical behaviors of lanthanides in molten salt. The in situ spectroscopic measurement system and studies according to temperature changes are essential for better understandable information. To our knowledge, the absorption studies of lanthanides at high temperatures have been reported before, but the fluorescence studies of those at high temperature are not reported yet. We will discuss here the fluorescence behaviors of lanthanides in LiCl-KCl molten ...
Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion ...
Additional measurements have been made of deposition and retention of inhaled radioactively labeled iron oxide aerosols generated by a spinning top aerosol generator.
For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO{sub 2}, PrO{sub 2}), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare earth elements ...
For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO2, PrO2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes: small cubic (oxide) and large plate-like (tetragonal) structures. The conversion efficiencies of the rare earth elements to their ...
The static thermophysical properties of the molten salt system like LiF-NaF-BeF_2 influence the design and construction of the fuel salt and coolant in the Molten Salt Reactor for the new generation. In this paper, the equation of state of the ternary system 0.15LiF-0.58NaF-0.27BeF_2, over the temperature range from 873.15K to 1073.15K at one atmosphere pressure, is described by using modified Peng-Robinson equation. The density of the ternary system is evaluated by this equation directly, and compared with the experimental data. Base on the equation of state, the other static thermophysical properties such as the enthalpy, entropy and heat capacity at constant pressure are evaluated by the fugacity coefficient and residual function methods respectively. The density calculated by Peng-Robinson equation is in highly agreement with the experimental data, and the enthalpy, entropy and heat capacity evaluated by such two ...
The static thermodynamic properties of the molten salt system like LiF-NaF-BeF_2 influence the design and construction of the fuel salt and coolant in the Molten Salt Reactor for the new generation. In this paper, the equation of state of the ternary system 15%LiF-58%NaF-27%BeF_2, over the temperature range of 873.15K to 1073.15K at one atmosphere pressure, is described using Peng-Robinson equation modified by us. And the density of the ternary system is evaluated by this equation directly, and compared with the experimental data. Base on the equation of state, the other static thermodynamic properties such as the enthalpy, entropy and heat capacity at constant pressure are estimated by the residual function method and the fugacity coefficient method respectively. The density calculated by Peng-Robinson equation is in highly agreement with the experimental data, and the enthalpy, entropy and heat capacity evaluated by such ...
The static thermophysical properties of the molten salt system like LiF-NaF-BeF2 influence the design and construction of the fuel salt and coolant in the Molten Salt Reactor for the new generation. In this paper, the equation of state of the ternary system 0.15LiF-0.58NaF-0.27BeF2, over the temperature range from 873.15K to 1073.15K at one atmosphere pressure, is described by using modified Peng-Robinson equation. The density of the ternary system is evaluated by this equation directly, and compared with the experimental data. Base on the equation of state, the other static thermophysical properties such as the enthalpy, entropy and heat capacity at constant pressure are evaluated by the fugacity coefficient and residual function methods respectively. The density calculated by Peng-Robinson equation is in highly agreement with the experimental data, and the enthalpy, entropy and heat capacity evaluated by such two ...
Alloy 800 has been proposed for use in the receiver tube panel arrays of advanced solar central receiver (SCR) designs. In this application the alloy will be exposed to a molten mixture of sodium and potassium nitrate salts at temperatures ranging up to approximately 600/sup 0/C While these salts are routinely used in a variety of applications including metal heat treating and process heat transfer, common industrial experience has been limited to maximum temperatures of 400/sup 0/C - 450/sup 0/C. There is, therefore, considerable interest in the compatibility of these salts with containment alloys at the higher temperatures associated with SCR designs. Additionally, the containment alloy may be subject to thermally induced fatigue damage resulting from intermittent cloud cover and diurnal cycling. Previous work has found that slower near-threshold fatigue crack growth rates (FCGR) in Alloy 800 result when it is tested in ...
Development of evaluation technology of electrochemical reactions is very essential to understand chemical behavior of actinides and lanthanides in molten salt media in relation to the development of Pyrochemical process. The on-line electrochemical/spectroscopic measurement system is to produce electrochemical parameters and thermodynamic parameters of actinides and lanthanides in molten salts by using spectroscopic techniques such as UV-VIS absorption as well as electrochemical in-situ measurement techniques. The on-line electrochemical/spectroscopic measurement system can be applied to understand the chemical reactions and oxidation states of actinides and lanthanides in molten salts eventually for the Pyrochemical process
Experimental data on the gas holdup and the mean bubble size in a bubble column with a single nozzle was obtained for gas-molten salt systems of a eutectic mixture of LiCl (58 mol %)-KCl (42 mol %) and molten NaNO/sub 3/. The liquid-phase mass transfer coefficient K /SUB L/ was evaluated from the specific surface area a and the volumetric coefficient K /SUB L/ a data for oxygen and carbon dioxide absorption into molten NaNO/sub 3/. The dimensionless correlations of the performance of bubble columns for aqueous solutions can be extended to the gas-molten salt systems.
As part of our effort to develop a semicontinuous PuO/sub 2/ reduction process, we are investigating promising materials for containing a 900/sup 0/C molten CaCl/sub 2/ . CaO chlorination reaction. We want the material to contain this reaction and to be reusable. We tested candidate materials in a simulated salt (no plutonium) using anhydrous HCl as the chlorinating agent. Data are presented on the performance of 36 metals and alloys, 9 ceramics, and 3 coatings.
Lithium was selectively extracted from near-neutral aqueous solutions of alkali metal salts. The mechanism by which this was achieved involves the formation of the trioctylphosphine oxide adduct of a lithium chelate of a fluorinated #beta#-diketone, which is then readily extractable into an organic diluent. High separation factors were obtained from sodium, potassium, rubidium, and cesium. The selectivity of the fluorinated #beta#-diketones for lithium over the alkaline earths was found to be poor. A suggested general flowsheet for the recovery of lithium from a salt brine concentrate is included. (author).
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.).
Completion of the Phase III evaluation and comparison of salt disposition alternatives was supported with enhanced computer models and analysis for each case on the ''short list'' of four options. SPEEDUP(TM) models and special purpose models describing mass and energy balances and flow rates were developed and used to predict performance and production characteristics for each of the options. Results from the computational analysis were a key part of the input used to select a primary and an alternate salt disposition alternative.
To improve adherent properties of electrogalvanized steel (EGS) to polymeric topcoats, the surfaces of EGS were modified by polyelectrolyte-modified zinc phosphating solution. The electrochemical reaction between phosphating solution and EGS led to the complete coverage with fully grown hopeite crystals after only 5 sec treatment, thereby improving adhesion to topcoating and providing protection of EGS against corrosion. To evaluate the ability of polyphenylene sulfide (PPS) polyaryl thermoplastic coatings to protect zinc phosphate (Zn{center_dot}Ph)treated steels from corrosion in a wet, harsh environment ( 1.0 wt % H{sub 2}SO{sub 4}, 3.0 wt % NaCl and 96.0 wt % water at temperatures from 25{degrees} to 200{degree}C), we exposed them in an autoclave to attempt heating-cooling cyclic fatigue tests (1 cycle = 12 hr at 200{degrees}C + 12 hr at 25{degrees}C) up to 90 times. The major chemical reaction at the interface between the PPS and Zn in the Zn-Ph layer during cycling led to the ...
The Rio Grande alluvial floodplain aquifer between El Paso/Juarez and Fort Quitman, Texas has been intensively tilled and irrigated since 1910. Almost since that time, the Rio Grande and its interconnected alluvial aquifer in this stream reach have been affected by excessive salinity problems. Presently, salinity of surface water and groundwater increases from 800 to 2000 mg/L total dissolved solids (TDS) near El Paso, Texas to 2500 to 5500 mg/L TDS near Fort Quitman, Texas, approximately 115 km downstream. Chloride (Cl) and Chloride/Bromide (Cl/Br) ratios increase downstream, with a marked increase in salinity beginning about 45 km below El Paso. Groundwater sampling in an intensively investigated reach of the floodplain aquifer, extending from 35 to 60 km below El Paso identified two distinct water types. The first water type (17 samples) is a relatively dilute groundwater containing 1000 to 2000 mg/L TDS, 250 to 600 mg/L Cl, and Cl/Br weight ratios of 550 to 900. The second ...
For the reuse of a waste salt from an electrorefining process of a spent oxide fuel, a separation of rare earth elements by an oxidative precipitation in a LiCl-KCl molten salt was tested without using precipitate agents. From the results obtained from the thermochemical calculations by HSC Chemistry software, the most stable rare earth compounds in the oxygen-used rare earth chlorides system were oxychlorides (EuOCl, NdOCl, PrOCl) and oxides (CeO2, PrO2), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides and oxides were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two sha...
An oxidative precipitation reaction of rare-earth chlorides in a LiCl-KCl molten salt was successfully carried out by a lab-scale apparatus. The conversion efficiency of the used rare earth chlorides into the insoluble precipitates was increased with the sparging time and temperature and was affected on oxygen sparger type. In the conditions of 700 .deg. C molten salt temperature and above 540min sparging time, the final conversion efficiencies were over 99% for all the experimented rare-earth chlorides. The hydrodynamic characteristics of an oxygen-molten salt two phase flow system are very important for a co-oxidative precipitation of rare earth elements.
An oxidative precipitation reaction of rare-earth chlorides in a LiCl-KCl molten salt was successfully carried out by a lab-scale apparatus. The conversion efficiency of the used rare earth chlorides into the insoluble precipitates was increased with the sparging time and temperature and was affected on oxygen sparger type. In the conditions of 700 .deg. C molten salt temperature and above 540min sparging time, the final conversion efficiencies were over 99% for all the experimented rare-earth chlorides. The hydrodynamic characteristics of an oxygen-molten salt two phase flow system are very important for a co-oxidative precipitation of rare earth elements
Results are presented from a numerical model of the steady-state energy transfer in molten-salt-in-tube solar cavity receivers that includes convective energy transfer at a local (spatially resolved) level. Molten salt energy absorption and gray radiative transfer between all cavity surfaces are also included. This model is applied to the Molten Salt Subsystem Component Test Experiment (MSS/CTE) cavity receiver. Results for this receiver indicate the global (entire cavity) receiver thermal efficiency is invariant within a few percent to most parameters investigated, although front surface temperatures of the nonabsorbing walls vary considerably, and are particularly sensitive to the type of convective submodel used. Absorption efficiencies indicate the effects of the cavity enclosure environment. For all conditions investigated, tube inner wall temperatures remain under 855 K, ensuring that the salt ...
The design of a global steady-state thermal model of a 100kWt molten salt cavity receiver was developed as part of the key project of the Ministry of Science and Technology of People's Republic of China (MOST). In the design process, the following factors were analyzed: receiver area, heat loss (convective, emissive, reflective and conductive), number of tubes in the receiver panel, tube diameter and receiver surface temperature. The model was also used to calculate the receiver performance of the Sandia National Laboratories' molten salt electric experiment (MSEE). In addition, the thermal performance of the designed molten salt cavity receiver is presented for a fixed outlet flow rate and a fixed output temperature.
This research investigated the inhibiting effects that sodium salts of linear monocarboxylic acids displayed towards the corrosion process of AZ31 Mg alloy in ASTM D 1387 saline solution (a synthetic industrial cooling water). The length of the aliphatic chain of the acids ranged between 7 and 15 carbon atoms. The inhibiting action of these salts can be related to the precipitation of an insoluble magnesium salt, which mainly affected the anodic reaction. The aliphatic chain length controlled the anion solubility and the reaction rate of magnesium carboxylate formation. For all the salts, an optimum concentration was experienced: 10{sup -2} M for sodium decanoate (caprate), 10{sup -3} M for sodium dodecanoate (laurate), 10{sup -4} M for sodium tetradecanoate (myristate); when this concentration was exceeded, a diminution (even a disappearance) in the inhibiting action was found. (Abstract Copyright ...
Jul 21, 1998 ... Additional roof surface temperatures were taken with a handheld "heat spy," an infrared thermometer to help calibrate the ATLAS thermal ...
The electrochemical/spectroscopic integrated measurement system was designed and set up for spectro-electrochemical measurements of lanthanide and actinide ions in high temperature molten salt media. A compact electrochemical cell and electrode system was also developed for the minimization of reactants, and consequently minimization of radioactive waste generation. By applying these equipment, oxidation and reduction behavior of lanthanide and actinide ions in molten salt media have been made. Also, thermodynamic parameter values are determined by interpreting the results obtained from electrochemical measurements. Several lanthanide ions exhibited fluorescence properties in molten salt. Also, UV-VIS measurement provided the detailed information regarding the oxidation states of lanthanide and actinide ions in high temperature molten salt media
To our knowledge, the fluorescence studies of lanthanides in LiCl-KCl eutectic molten salt at a high temperature are not reported yet. The fluorescence of the lanthanide-ions was generally decreased when the temperature was increased. Moreover, the fluorescence of the lanthanides was strong when the sample was solidified to or from the melt. The temperature, where the fluorescence was decreased, was identified to be different depending on the species of the lanthanides and the substrates was considered to possibly be from quenching of the fluorescence due to either the collisions of melted samples induced by high temperature media or the re-absorption of fluorescence by the samples. Several comparison experiments were performed to explain and understand this phenomenon and improve the fluorescence. In this way, an on-line monitoring of chemical species and the concentration for lanthanides elements in molten salt media of pyrochemical process ...
Normally, concrete technologists attribute salt weathering, salt crystallization or physical attack to the deterioration of concrete that is partially exposed to sulfate environment. However, there are few convincing evidences supporting this view. The purpose of this paper is to check by means of extensive micro-analysis if traces of sulfate crystals are present in the paste. This would enable to verify in a direct way whether salt weathering really causes cement paste damage or not.In this research, cement paste and cement?fly ash paste specimens were partially exposed to sodium sulfate and magnesium sulfates solution under a constant storage condition (20 ? 2 ?C, and 60 ? 5% RH) and a sharply fluctuating environment (40 ? 2 ?C and 35 ? 5% RH for 24 h, then 10 ? 1 ?C and 85 ? 5% RH, also...
Ultimate Compressive Strength of Short Sheet - Stringer Panels With Special. Reference to the Influence of the Riveted Connection Between Sheet and Stringer ...
... a given ternary molten salt system under conditions which are greatly " different than the normal method of potentiometric titration, that is, high ...
The molten salt reactor (MSR), which is one of the generation IV reactors, can meet the demand of transmutation and breeding. The thermodynamic properties of the molten salt system like LiF-NaF-BeF2 influence the design and construction of the fuel salt and coolant in the MSR for the new generation. In this paper, the equation of state of the ternary system 15%LiF-58%NaF-27%BeF2, over the temperature range from 873.15 to 1 073.15 K at one atmosphere pressure, is described using a modified Peng-Robinson (PR) equation. The densities of the ternary system and its components are estimated by this equation directly, and compared with the experimental data. Based on the equation of state, the other thermodynamic properties such as the enthalpy, entropy and heat capacity at constant pressure are ...
Pyrochemical processing of nuclear fuels using molten salts has attracted much attention because of its potential to be applied for a future spent nuclear fuel management. In the pyrochemical processing, there are a number of steps to electro-refine and electro-win each element of lanthanides and actinides, commonly called trans-uranic elements (TRU). In order to materialize the pyrochemical processing in the nuclear power plant environments, qualitatively and quantitatively monitoring of each elements is necessary. Thus, we have undertaken to develop an on-line observing system of the TRU in LiCl-KCl molten salt media by using electrochemical and spectroscopic methods. In this work, the electrochemical and spectroscopic behaviors of europium as a proxy material for TRU were investigated simultaneously in the LiCl-KCl molten salt.
Pyrochemical processing of nuclear fuels using molten salts has attracted much attention because of its potential to be applied for a future spent nuclear fuel management. In the pyrochemical processing, there are a number of steps to electro-refine and electro-win each element of lanthanides and actinides, commonly called trans-uranic elements (TRU). In order to materialize the pyrochemical processing in the nuclear power plant environments, qualitatively and quantitatively monitoring of each elements is necessary. Thus, we have undertaken to develop an on-line observing system of the TRU in LiCl-KCl molten salt media by using electrochemical and spectroscopic methods. In this work, the electrochemical and spectroscopic behaviors of europium as a proxy material for TRU were investigated simultaneously in the LiCl-KCl molten salt
Development of New Methods and Means of Assessing of Consequences of Radionuclide and Heavy Metal Salt Effect, Criteria of Forecasting Physiological State and Productivity of the Farm Animals under Conditions of Ecological Pollution of Environment
Interactions (FCCI) University of Wisconsin, Madison Thermal Properties of LiCl-KCl Molten Salt for Nuclear Waste Separation University of Wisconsin, Madison Next Generation...
A novel liquid phase alkylation of aniline with methanol over Zn/Cu salts modified kaolin assisted with a pair of porous carbon electrode in slurry-bed reactor under constant current intensity, room temperature and atmospheric pressure was reported. The Zn/Cu salts modified kaolin catalysts were synthesized and characterized by infrared spectrometer (IR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), which showed that the transition metals were completely supported on kaolins structure and formed a pored one. The effect parameters, such as initial pH, electrolysis time, metal ratio with kaolin and salts composition in this electrochemical catalytic system, were studied. The procedure was inspected by ultraviolet-visible spectrum (UV-vis), and the product distributi...
This report attempts to bring together available information on the coal deposits of Antarctica and discuss factors that would be involved if these deposits were to be explored and mined. Most of the reported principal coal deposits in Antarctica lie generally within the Transantarctic Mountains: the majority are of Permian age and are present in the Victoria Group of the Beacon Supergroup. Several other deposits have been recorded in East Antarctica and in the Antarctic Peninsula, including minor occurrences of Mesozoic and Tertiary coal and carbonaceous shale.
In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was ...
The possibilities to grow isolated structures of complex oxides by pulsed laser deposition through stencils were investigated. A stencil consisting of a SiN membrane with apertures of several hundred nanometers embedded in a Si chip is placed in front of a heated substrate (up to 750 degrees Celsius). Deposition through these apertures results in resistless, direct patterning by local deposition of complex oxides like ferroelectric Lead Zirconate Titanate. The created isolated structures were analyzed by AFM imaging. Under-deposition, in this work called broadening, is inevitable during stencil deposition and is depending on deposition parameters, especially pressure. Different causes of broadening are mapped and discussed.
In an effort to minimize the distortion of bearing steel rings during the production process, 100Cr6 steel billets are spray formed with a unique cooling control system to control the cooling and solidification behavior of the deposits. Effects of heating around the deposits, gas cooling at the substrate bottom and the gas flow over the deposits are investigated both by numerical simulation and experiment. Porosity profiles and microstructures of spray formed bearing steel are examined and evaluated. The investigation results show that the thermal boundary conditions of the deposits play important roles on the cooling and solidification behavior of the deposits, especially at the deposit periphery. Porosity in the 100Cr6 bearing steel deposit can be reduced significantly with the special cooling control system.
YBa_2Cu_3O_7_-_x thick films have been deposited on silver sheets and MgO single crystals by spray pyrolysis. Film texture is related to film thickness and sintering temperature. The X-ray intensity ratio of the 005 peak to the 110 peak is higher for thin films deposited at the higher temperatures. However, elevated temperatures promote copper diffusion and second-phase formation in films deposited on silver. Films deposited on MgO can have larger grain sizes and are more oriented than those deposited on silver.
Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)
A new magnetic macroparticle filter design consisting of two 90{sup o} filters forming an S-shape is described. Transport properties of this S-filter are investigated using Langmuir and deposition probes. It is shown that filter efficiency is product of the efficiencies of two 90{sup o} filters and the deposition rate is still acceptably high to perform thin film deposition. Films of amorphous hard carbon have been deposited using a 90{sup o} filter and the S-filter, and macroparticle content of the films are compared.
Results are given for deep-level petroleum and gas drilling probes in various coastal zones of Southern Sakhalin covering the Poronai depression and the Aniv Bay trough. The exploratory probes indicate that the Middle Miocence deposits of the Boundary trough contain commercial-size deposits of petroleum, that commercial-size gas deposits are in the upper Myocene deposits of the Aliv Bay trough, and that the upper Cretaceous and Cenozoic deposits of the eastern section of Southern Sakhalin lack folded deformations. 7 references, 2 figures.
The understanding of fission product deposition in realistic steam generator conditions is needed for release estimates in PSA studies, and for the design of efficient accident management procedures. This is considered very important because primary-to-secondary leakages risk dominant sequences in many plants. Furthermore, the decay heat of the fission product deposits adds to the thermal load to the steam generator tubes also in other sequences, especially in case of cold leg leakages. This brings out the concern of induced steam generator tube ruptures in cases, where the steam generators are initially intact. The experimental data showed that the highest deposited fraction within the tubes were found in cases with lowest flow velocities. The minimum value of the deposited fraction was observed at intermediate flow velocities. With these relatively low Reynolds numbers, the results calculated with ...
The understanding of fission product deposition in realistic steam generator conditions is needed for release estimates in PSA studies, and for the design of efficient accident management procedures. This is considered very important because primary-to-secondary leakages risk dominant sequences in many plants. Furthermore, the decay heat of the fission product deposits adds to the thermal load to the steam generator tubes also in other sequences, especially in case of cold leg leakages. This brings out the concern of induced steam generator tube ruptures in cases, where the steam generators are initially intact. The experimental data showed that the highest deposited fraction within the tubes were found in cases with lowest flow velocities. The minimum value of the deposited fraction was observed at intermediate flow velocities. With these relatively low Reynolds numbers, the results calculated with ...
The chemical reaction between nitric acid and sodium chloride was investigated in onder to provide preliminary information for subsequent studies on the interaction between simulated Purex waste solution and salt. The reaction is characterized by the production of chlorine and nitrosyl chloride and can be considered to be the same as the aqua regia reaction. Within the limits of the conditions imposed by the projected field studies, the acid concentration and temperature are the two parameters which control the extent of the interaction. (auth)
Advanced lithium batteries presently under development operate either at the high temperatures associated with the LiCl-KCl molten salt (350-450/degree/C), or at ambient temperatures employing organic solvent based electrolytes. An intermediate temperature lithium battery is proposed as an alternative if it reduces corrosion problems present at high temperatures and improved kinetic performance with respect to ambient temperature cells. 17 refs.
The following methods of quartz ceramics alloying were considered: alloying of initial quartz glass; introduction of alloying additive into water slip of quartz glass; porous materials impregnation with salt aqueous solutions and subsequent salt thermal decomposition with formation of stable oxides in pores of ceramics. Oxygen free compounds BN, SiB_4, SiC, Si_3N_4, REM oxides and transition metal oxides were used as alloying additives. Main properties of the materials and compositions obtained are presented.
A phosphorus-containing low alkali metal content zeolitic catalyst made from a clay starting material is provided. The catalyst is obtained by contacting a partially cation exchanged calcined zeolite-containing catalyst with an anion such as a dihydrogen phosphate anion or a dihydrogen phosphite anion and additionally with an ammonium salt other than a salt of an inorganic acid of phosphorus. A hydrocarbon catalytic cracking process utilizing the phosphorus-containing catalyst is also provided.
Elastic depth imaging of both P-wave and S-wave prestack seismic reflection data is formulated as a degraded form of Kirchhoff migration known as Wavepath Migration (WM). Applications to the SEG/EAGE salt model show that the method is sufficiently versatile anti relaitively inexpensive. It handles S-wave data with at least the same accuracy as Pwave data when local mode conversions are removed. WM also provides an understanding of multi-mode illumination.
The phytomanagement of Se-polluted soil and water is one strategy that may be environmentally sustainable and cost-effective for soils and waters enriched with natural-occurring Se. Several plant species, including Indian mustard (Brassica juncea), pickleweed (Salicornia bigelovii), and other salt/S...
This patent describes a catalyst comprising: (a) a non-zeolitic inorganic oxide matrix, and (b) an ultrastable Y-type crystalline zeolite, the ziolite having been pretreated by contacting the zeolite with a phosphorus compound selected from the group consisting of phosphoric acid, phosphorous acid, a salt of phosphoric acid, a salt of phosphorous acid, and mixtures thereof for a time sufficient to composite an effective amount of phosphorus with the zeolite.
Distribution of scattered elements in basic minerals of salt-rocks is studied. It is shown that rubidium and cesium are accumulated mainly in carnallites and are contained in small quantities halites. These elements are accumulated primarily in the carnallite production products, wherein their content in a number of cases exceeds by dozens and hundred times their content in source rocks. It is noted that only carnallites may be considered in the list of actual sources for rubidium and cesium separation
Molten salt oxidation (MSO) is proposed as a {sup 238}Pu waste treatment technology that should be developed for volume reduction and recovery of {sup 238}Pu and as an alternative to the transport and permanent disposal of {sup 238}Pu waste to the WIPP repository. In MSO technology, molten sodium carbonate salt at 800--900 C in a reaction vessel acts as a reaction media for wastes. The waste material is destroyed when injected into the molten salt, creating harmless carbon dioxide and steam and a small amount of ash in the spent salt. The spent salt can be treated using aqueous separation methods to reuse the salt and to recover 99.9% of the precious {sup 238}Pu that was in the waste. Tests of MSO technology have shown that the volume of combustible TRU waste can be reduced by a factor of at least twenty. Using this factor the present inventory of 574 TRU drums ...
Ammonia is a common and highly toxic pollutant which, in sufficient quantities, will adversely affect aquatic organisms. This ammonia criteria document for salt water will allow establishment of regulatory standards for ammonia discharge into estuaries, near coastal zones and oceans. Possible adverse impacts in highly sensitive and abundant ecosystems such as estuaries make regulation particularly important.
Interfacial tension in the system toluene solution of di-2-ethylhexylphosphoric acid HDEHP-aqueous solutions of inorganic salts has been measured by the drop volume method. The ion-exchange constants in the monolayers formed by HDEHP and alkaline-earth metals have been measured.
The syntheses of N-alkylated deoxynojirimycin and 1,5-dideoxy-1,5-iminoxylitol derivatives having either a D- or an L-erythritol-3-sulfate functionalized N-substituent are reported. The alkylating agent used was a cyclic sulfate derivative, whereby selective attack of the nitrogen atom at the least hindered primary center afforded the desired ammonium salt. In aqueous solution, these salts were configurationally labile at the ammonium center. Sulfonium and/or selenonium analogues of the ammonium salts were prepared by analogous reactions. The chalcogen salts were obtained as mixtures of diastereomers, separable in some cases, differing only in the stereochemistry at the configurationally stable sulfur or selenium atoms. Proof of configuration and conformation of each compound was obtained by detailed NMR experiments. The compounds are six-membered ring analogues of salacinol, a known ...
This report provides an overview of the scope and status of the US Department of Energy (DOE`s) Salt Repository Project (SRP) at the time when the project was terminated by the Nuclear Waste Policy Amendments Act of 1987. The report reviews the 10-year program of siting a geologic repository for high-level nuclear waste in rock salt formations. Its purpose is to aid persons interested in the information developed during the course of this effort. Each area is briefly described and the major items of information are noted. This report, the three salt Environmental Assessments, and the Site Characterization Plan are the suggested starting points for any search of the literature and information developed by the program participants. Prior to termination, DOE was preparing to characterize three candidate sites for the first mined geologic repository for the permanent disposal of high-level nuclear waste. The sites were in ...
Mixtures of organic-inorganic substances are studied for their performance as energy storage media. Use is made of the fact that organic substances give higher amounts of energy but within a wide range of temperature on the one side and the fact that inorganic substances give lower amounts of energy at constant temperature on the other side. Mixtures of both types of substances, in different ratios, are investigated for the object of determining that optimum composition which stores a higher amount of energy and, meanwhile, releases it at a constant temperature or within a narrow range of temperature. The mixtures used are composed of Glauber`s salt (Na{sub 2}SO{sub 4}.10H{sub 2}O) and stearic acid in different proportions. The effect of cooling fluid flow rate and ambient temperature as well as the effect of addition of a nucleating agent is studied. The results showed that the highest amount of energy stored could be obtained from a mixture containing 40% stearic ...
We present measurements of the transmission of radio/microwave pulses through salt in the Cote Blanche salt mine operated by the North American Salt Company in St. Mary Parish, Louisiana. These results are from data taken in the southwestern region of the 1500 ft. (457 m) deep level of the mine on our third and most recent visit to the mine. We transmitted and received a fast, high-power, broadband pulse from within three vertical boreholes that were drilled to depths of 100 ft. (30 m) and 200 ft. below the 1500 ft. level using three different pairs of dipole antennas whose bandwidths span 125 to 900 MHz. By measuring the relative strength of the received pulses between boreholes with separations of 50 m and 169 m, we deduce the attenuation of the signal attributed to the salt medium. We fit the frequency dependence of the attenuation to a power law and find the best fit field attenuation lengths to be ...
Four very common long term mineralogical changes in salt formations are discussed in the view of the safety considerations for underground repositories. Two of these processes, the 'Hartsalz' and 'Carnallite' dissolution were studied in two scale in situ experiments. The results are presented and compared with the results of the geochemical modelling with the computer code EQ3/6. Furthermore the reactions leading to the formation of the gypsum cap rock on the top of the Zechstein salt formations and to the polyhalitization of anhydrite are discussed. Geological field observations and mineral assemblages agree well with the results of the geochemical modelling employing the Pitzer formalism along with the Harvie, Moller and Weare database. We conclude that once the mechanisms of the chemical reactions are well understood it becomes possible to evaluate realistically whether such processes, when encountered in the repository, are still active or ...
Homozygous transgenic cotton (Gossypium hirsutum L.) plants that accumulated glycinebetaine (GB) in larger quantities were more tolerant to salt than wild-type (WT) plants. Four transgenic lines, namely 1, 3, 4, and 5, accumulated significantly higher levels of GB than WT plants did both before and after salt stress. At 175 and 275?mM NaCl, seeds of all the transgenic lines germinated earlier and recorded a higher final germination percentage, and the seedlings grew better, than those of the WT. Under salt stress, all the lines showed some characteristic features of salt tolerance, such as higher leaf relative water content (RWC), higher photosynthesis, better osmotic adjustment (OA), lower percentage of ion leakage, and lower peroxidation of the lipid membrane. Levels of endogenous GB in ...
The electrometallurgical treatment process described in this paper builds on our experience in treating spent fuel from the Experimental Breeder Reactor (EBR-II). The work is also to some degree, a spin-off from applying electrometallurgical treatment to spent fuel from the Hanford single pass reactors (SPRs) and fuel and flush salt from the Molten Salt Reactor Experiment (MSRE) in treating EBR-II fuel, we recover the actinides from a uranium-zirconium fuel by electrorefining the uranium out of the chopped fuel. With SPR fuel, uranium is electrorefined out of the aluminum cladding. Both of these processes are conducted in a LiCl-KCl molten-salt electrolyte. In the case of the MSRE, which used a fluoride salt-based fuel, uranium in this salt is recovered through a series of electrochemical reductions. Recovering high-purity uranium from an aluminum-matrix fuel is more challenging ...
Soils of arid regions of Central Asia contain salts of different types that may differentially affect seed germination and plant development. We studied effect of NaCl, Na2SO4, 2NaCl + KCl + CaCl2 and 2Na2SO4+K2SO4+MgSO4 on germination of Kochia prostrata and Kochia scoparia seeds under a range of concentrations from 0.5 to 5% and at two constant temperature regimes +22 degrees C and +6 degrees C. The observed salt tolerance limit of germination at constant temperature +22 degrees C for both species was 5-6%, while at low temperature (+6 degrees C) this limit was 2%. The salt tolerance of young plants (before flowering) was 3% for NaCl. Low concentrations of sulfuric and mixed salts had a stimulating effect on seed germination in K. prostrata. Despite similarity of salt-tolerance limits...
Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.
A methodology for the determination of the rare earth elements in uranium oxides by ion microprobe has been set up on a Cameca ims-3f instrument. An uranium oxide reference material from a syn-metamorphic uranium deposit related to albitisation has also been developed for this type of analysis. Applications of the methodology are presented for a series of uranium oxides selected from some major uranium deposit types: from the world's highest grade unconformity-related uranium deposit from the Athabasca Basin (Saskatchewan, Canada; the Shea Creek and the McArthur River examples), a perigranitic vein-type deposit (Pen Ar Ran, Vendee, France) and a volcanic caldera-related deposit (Streltsovkoye, Transbaikalia, Russia). Each type of uranium deposit appears to have a specific REE signature. Al...
In this paper we demonstrate the electrodeposition of nickel, a common ferromagnetic material, in various magnetically desirable shapes including nanowires, nanoparticles and highly faceted shells. In order to obtain three dimensional mesostructures, the electrochemical deposition of nickel was performed on highly oriented pyrolytic graphite (HOPG) under different electrolyte composition and deposition potential conditions. Under potentiostatic deposition at one distinct potential negative with respect to the reversible potential of nickel, three stages of nucleation and growth take place leading to a complex morphology of deposits. However, dual-pulse potential deposition and electrodeposition in low pH solutions causing hydrogen evolution, lead to nickel deposits in the form of nanowires...
A ternary nickel-base alloy Ni-W-B has been developed for surface corrosion and wear resistance to replace chromium plating, which uses environmentally hazardous solutions. The deposition conditions used an alkaline bath and insoluble anodes. The as-deposited alloy typically contains 40 wt% W and 1 wt% B and has an amorphous or partially amorphous structure. These deposits compare favorably with hexavalent chromium deposits in throwing power, color uniformity, and reflectivity. The corrosion resistance of Ni-W-B alloy was compared with hexavalent chromium and electroless nickel deposits in a variety of acids, including hydrochloric, sulfuric, fluoroboric, and phosphoric. In all cases, best results were obtained with the Ni-W-B deposits.
The precipitation reaction of some rare earth chlorides (La/Ce/Nd/GdCl3) in a LiCl-KCl molten salt has been carried out by using the oxygen sparging method. In this study, regardless of the oxygen sparging time and the molten salt temperature, oxychlorides (REOCl) for LaCl3, NdCl3 and GdCl3, and an oxide (REO2) for CeCl3 are formed as a precipitate. The conversion of rare-earth chlorides into insoluble precipitates was described by using a conversion ratio. The conversion ratio increased exponentially with the oxygen sparging time and finally showed asymptotic value at 1,023K of the molten salt temperature condition. The conversion ratios of LaCl3, NdCl3 and GdCl3 were increased with the molten salt temperature, however, even though the conversion ratio was increased from 0.660 to 0.995 with increasing molten salt temperature from 823 to 923 K at 60 min of a sparging time, the ...
A solar energy desalination process utilizing solar radiation directly for the evaporation of salt water is described. Ambient air takes on water vapor as the air passes through an evaporative medium. It is then directed between a saline water-covered, solar absorbing surface and a solar collecting housing. The resulting heated and moisture-saturated air is cooled in a heat exchange means where condensation of fresh water occurs. Simultaneously, cool salt water is utilized as the cooling water in the heat exchange means, and takes on the heat of condensation given up by the condensing vapor. The heated salt water from the heat exchange means is partially directed over the solar absorbing surface, and at least a portion of it is also directed to wet the evaporative medium. Several optional sub-processes are described for operation of the system during periods of reduced insolation, and an alternative process is described for ...
Large quantities of organic chemicals used in reprocessing spent nuclear-fuels at the Hanford Site have accumulated in underground high-level radioactive waste tanks. The organic content of these tanks must he known so that the potential for hazardous reactions between organic components and sodium nitrate/nitrite salts in the waste can he evaluated. The solubilities of organic compounds described in this report will help determine if they are present in the solid phases (salt cake and sludges) as well as the liquid phase (interstitial liquor/supernate) in the tanks. The solubilities of five significant sodium salts of carboxylic acids and aminocarboxylic acids [sodium oxalate, formate, citrate, nitrilotriacetate (NTA) and ethylendiaminetetraacetate (EDTA)] were measured in a simulated supernate solution at 25 degrees C, 30 degrees C, 40 degrees C, and 50 degrees C.
Counter-current regeneration of 2-stage sodium zeolite softeners has been employed in reducing hardness leakage level of steamflooding water to less than 1 ppm when raw water contains as much as 5,000 ppm of the total dissolved solids. Hardness leakage is caused by sodium displacement of calcium and magnesium from the bottom of the exchanger bed. This study presents nomographs providing for rapid calculations to be made, for which a convenient operational mode does not already exist. The nomographs relate the hardness leakage as a function of salt quality and influent water quality and present solutions for predicting the leakage level, salt quality requirement or the treatability of raw water required for steamflooding projects.
The crystal structure of Ca{sub 2}RuD{sub 6} has been determined by neutron powder diffraction: space group Fm3m, K{sub 2}PtCl{sub 6} structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340 K and 50 K. The deuterium nuclear quadrupole coupling constant, 54.7 kHz, leads to an ionic character of the Ru-D bond of 76%. The known trends in the behaviour of A{sub 2}MH{sub 6} salts are interpreted in terms of the ionization energies of the cation and the central metal atom.
The crystal structure of Ca2RuD6 has been determined by neutron powder diffraction: space group Fm3m, K2PtCl6 structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340K and 50K. The deuterium nuclear quadrupole coupling constant, 54.7kHz, leads to an ionic character of the Ru-D bond of 76%. The known trends in the behaviour of A2MH6 salts are interpreted in terms of the ionization energies of the cation and the central metal atom.
Spherical nano-sized YSZ (yttria stabilized ZrO2) powders were successfully synthesized via a reverse microemulsion system. The water droplets in the microemulsion system of yclohexane/water/span85/Triton X-100/hexyl alcohol can act as the nano-reactors which solubilize zirconium oxychloride and ammonia water separately. The minute original reactors are favor to the formation of nano-sized spherical YSZ powders and the dispersibility of the powders can be controlled effectually by adjusting the weight ratio of the LiNO3 molten salt to the precursor. The phase transformation from cubic to monoclinic starts at and 500??C and finally monoclinic and cubic phase with increased crytallinity coexist at 800??C. The effect of LiNO3 molten salt in the formation of YSZ powders was also discussed.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu{sub 2}O{sub 3} as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu_2O_3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723K by using Eu2O3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
Decontamination and decommission activities related to the Molten Salt Reactor Experiment (MSRE) involve the trapping and recovery of radiolitically generated uranium hexafluoride and fluorine. Although fission product radiolysis was known to generate F{sub 2}, the formation of UF{sub 6} and its transport from the fuel salt was unexpected. Some of these gaseous radiolysis products have been moving through the gas piping to a charcoal bed since the reactor was shut down in 1969. Current and planned remediation and clean-up activities involve the trapping of the gaseous products, deactivation and treatment of the activated charcoal bed, stabilization and reconditioning of the fuel salt, and recovery of the uranium. The chemical aspects of these processes, including radiolytic generation mechanisms, reactions between uranium hexafluoride and fluorine and trapping materials such as activated charcoal, activated alumina, and ...
We review a new theoretical approach to the kinetics of surfactant adsorption at fluid-fluid interfaces. It yields a more complete description of the kinetics both in the aqueous solution and at the interface, deriving all equations from a free-energy functional. It also provides a general method to calculate dynamic surface tensions. For non-ionic surfactants the results coincide with previous models. Common non-ionic surfactants are shown to undergo diffusion-limited adsorption, in agreement with experiments. Strong electrostatic interactions in salt-free ionic surfactant solutions are found to lead to kinetically limited adsorption. In this case the theory accounts for unusual experimental results which could not be understood using previous approaches. Added salt screens the electrostatic interactions and makes the ionic surfactant adsorption similar to the non-ionic case. The departure from the non-ionic behavior as the ...
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
Analytical relations are obtained for estimating how the distributions of temperature and heat flux vary along a steam-generating tube and how the steam-generator power output reduces due to formation and accumulation of deposits.
The reactive evaporation process was successfully used to deposit films of the A-15 Nb_3Ge phase. This is the first report, to the best of our knowledge, illustrating the use of such processes for the deposition of A-15 compounds. In this process, niobium vapors from an electron-beam-heated evaporation source react with germane gas introduced into the vacuum chamber at low partial pressures (approximately 10"-"4 Torr) to produce Nb_3Ge deposits. The process variables studied were the deposition temperature, the niobium-to-germanium impingement ratio on the substrate and the plasma-enhanced deposition, in this case the activated reactive evaporation process. At low deposition temperatures (below 450"0C) the deposit is amorphous (or microcrystalline) and can be crystallized to the Nb_3Ge phase by heat treatment, e.g. at 850"0C for 1 h in ...
This report results from a contract tasking Eindhoven University of Technology as follows: The contractor will investigate the plasma treatment of surfaces and plasma enhanced deposition using EUT's cascade arc source as the basis for this effort.
Pulsed laser deposition (PLD) is known for its capacity to reproduce a target composition on a substrate. The authors have used this deposition technique to produce thin films of transition metal chalcogenides. However, the deposits were always deficient in Te relative to the starting material (composed by a refractory metal (niobium) and a chalcogene (tellurium)). Variations of the interreticular distances have been observed with respect to fluence and substrate temperature. The authors show that spatial composition of the films is determined by a degree of crystallinity of deposit and by the reaction of formation of Te{sub 2} molecule within laser induced plume. Two kinds of deposits have been obtained: Nb{sub 5}Te{sub 4}-type thin films which have a one-dimensional structure and NbTe{sub 2}-type thin films which have a two-dimensional structure. While NbTe{sub 2} films have been ...
The report is divided into six working group discussions on the following subjects: 1) Chemical and physical mechanisms in the formation of uranium mineralization, geochronology, isotope geology and mineralogy; 2) Sedimentary basins and sandstone-type uranium deposits; 3) Uranium in quartz-pebble conglomerates; 4) Vein and similar type deposits (pitchblende); 5) Other uranium deposits; 6) Relation of metallogenic, tectonic and zoning factors to the origin of uranium deposits. Each working group paper contains a short introductory part followed by a discussion by the working group members.
Adult and newborn rats were exposed to "2"3"9PuO_2 aerosols of four different size distributions. Rats of both ages were killed at intervals between 1 hr and 60 days postexposure. There were marked age- and particle-related size differences in deposition, although retention was similar throughout. The differences in deposition are attributable to relatively greater deposition of larger particles in the upper respiratory tracts of newborns.
... analyzer section for angle resolved measurements, and a thin film evaporator with a quartz crystal microbalance to measure the mass deposition. ...
A compact cesium deposition system was used for direct deposition of cesium atoms and ions onto the inner surface of the 1/3 scale Hydrogen Negative Ion Source for the LHD-NBI system. A small, well defined amount of cesium deposition in the range of 3-200 mg was tested. Negative ion extraction and acceleration were carried out both in the pure hydrogen operation mode and in the cesium mode. Single Cs deposition of 3-30 mg to the plasma chamber have produced temporary 2-5 times increases of H-yield, but the yield was decreased within several discharge pulses to the previous steady-state value. Two consecutive 30 mg depositions done within a 3-5 hours/60 shot interval, produced a similar temporary increase of H-beam, but reached a larger H-yield steady-state value. Deposition of larger 0.1-0.2 g Cs portions with a 20-120 hours/150-270 shot interval improved the ...
The hydrogen evolution reaction (HER) was studied on Ni-P{sub x} electrodes containing 8 to 16 weight percent P prepared by potentiostatic deposition. The amount of P in the alloy varied with deposition potential. The activity of the electrodes was dependent on the P concentration, and the formation of a passive film. Cyclic voltametry was used to study the removal of this film. 3 refs.
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.
Amyloid-β (Aβ) deposits have been identified as key players in the progression of Alzheimer’s disease (AD). Recent evidence indicates that the deposits probably precede...Full Text Available
This report measured the rate of isothermal deposition of sub-micron particles of magnetite onto the surface of Alloy 800 at pH of 4.2-9.3 at Re=10,000 and a fluid temperature of 25C. Deposition is modelled as a two-step process, the transport of particles to the surface region followed by attachment to the surface.
High salinity is one of the main factors limiting cotton growth and productivity. The genes that regulate salt stress in TM-1 upland cotton were monitored using microarray and real-time PCR (RT-PCR) with samples taken from roots. Microarray analysis showed that 1503 probe sets were up-regulated and 1490 probe sets were down-regulated in plants exposed for 3h to 100mM NaCl, and RT-PCR analysis validated 42 relevant/related genes. The distribution of enriched gene ontology terms showed such important processes as the response to water stress and pathways of hormone metabolism and signal transduction were induced by the NaCl treatment. Some key regulatory gene families involved in abiotic and biotic sources of stress such as WRKY, ERF, and JAZ were differentially expressed. Our transcriptome analysis might provide some useful insights into salt-mediated signal transduction pathways in cotton and offer a number of candidate genes as potential ...
Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI...Full Text Available
In the labellar chemosensory hairs of the blowfly, Phormia regina Meigen, stationary amplitudes of the slow potentials induced by salt and sugar stimulations were decreased to 50–80%...Full Text Available
Describes laboratory and industrial tests on the use of lowasash sulphurous petroleum coke during reduction of barite. Shows the potential of substituting blast furnace coke with petroleum/coke fines in this process.
Analysis of results of an investigation into the structure of lithium salt aqueous solutions is presented. An anomaly in lithium ion behaviour in solutions at the structural level is noted. 40 refs., 3 tabs.
Starting from the Molten Salt Breeder Reactor project of Oak-Ridge, we have performed parametric studies in terms of safety coefficients, reprocessing requirements and breeding capabilities. In the frame of this major re-evaluation of the molten salt reactor (MSR), we have developed a new concept called Molten Salt Fast Reactor or MSFR, based on the Thorium fuel cycle and a fast neutron spectrum. This concept has been selected for further studies by the MSR steering committee of the Generation IV International Forum in 2009. Our reactor's studies of the MSFR concept rely on numerical simulations making use of the MCNP neutron transport code coupled with a code for materials evolution which resolves the Bateman's equations giving the population of each nucleus inside each part of the reactor at each moment. Because of MSR's fundamental characteristics compared to classical solid-fuelled reactors, the classical Bateman ...
Refractory ascites can occur in patients with various conditions. Although several procedures based on the reinfusion of ascitic fluid have been reported after the failure of bed rest, salt and water...Full Text Available
OBJECTIVE--To examine the effect of a reduced sodium and increased potassium and magnesium intake on blood pressure. DESIGN--Randomised double blind placebo controlled trial. SETTING--General population...Full Text Available
The osmoprotectant Pro betaine is the main betaine identified in alfalfa (Medicago sativa). We have investigated the long-term responses of nodulated alfalfa plants to salt stress,...Full Text Available
Rat somatotropin (growth hormone) was labelled biosynthetically by incubating anterior pituitary lobes with radioactive amino acids for 24 h in a simple buffered salts medium containing glucose. The...Full Text Available
Plant roots exhibit remarkable developmental plasticity in response to local soil conditions. It is shown here that mild salt stress stimulates a stress-induced morphogenic response (SIMR) in Arabidopsis...Full Text Available
The estimation of numerical values of the mean distance of closest approach of ions, a, of alkaline-earth metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.
The corrosion behavior of Ta, Ti, and Zr in inorganic acids, bases, chlorides and miscellaneous salts, waters and gases, and organic acids and miscellaneous organic chemicals is summarized. (W.L.H)
For the development of high ionic conductive solid electrolyte, LiTi2(PO4)3 (LTP), one of the promising inorganic solid electrolyte, was synthesized to investigate an effect of additional lithium salt on the ion conductivity. Lithium salt added LTP composite electrolyte sintered at 900{degree}C exhibited highest conductivity, which was two order magnitude higher than pure LTP. Effects of lithium salt addition are as follows. Conductivity of the composite electrolyte provided larger sintering temperature dependence than the pure LTP. From X-ray diffraction analysis, structures and compositions were resemble between two composite electrolytes. Byproducts except LTP provided rather low conductivity. It was suggested that melted constitution in the composite can affect the sintering improvement by the additional lithium salt at temperatures over 800 {degree}C. From the observation of ruptured surface of ...
Absorption of lead is known to be enhanced during infancy. In this study, the sites of intestinal accumulation of Pb by suckling rats have been determined under various conditions using "2"0"3Pb as a tracer. When "2"0"3Pb was administered intragastrically (IG) as a soluble salt, accumulation occurred primarily in the duodenum, regardless of dose and vehicle. In contrast, when rat pups suckled from a dam which had received "2"0"3Pb, the only region of the small intestine showing accumulation of radioactivity was the ileum. To confirm that these differences were not related to the route of administration, rat milk was labeled with "2"0"3Pb and was then used for IG administration. Once again, accumulation (4 hr post-administration) was confined to the ileum. When the dose was increased 10-fold, milk Pb displayed some accumulation in duodenal tissue, but very much less than that of soluble Pb at the same time and dosage. At 20 hr postadministration, there was ...
Urmia Lake has been designated as an international park by the United Nations. The lake occupies a 5700 km2 depression in northwestern Iran. Thirteen permanent rivers flow into the lake. Water level...Full Text Available
The solubilities of plutonium and uranium have been determined for alkaline salt solutions having compositions which bound those which will be processed in the In-Tank Precipitation (ITP) process. Loadings of plutonium and uranium onto monosodium titanate (MST) have been determined at temperatures bounding those expected to occur during ITP and using a salt solution which was determined to have the maximum solubility for uranium and plutonium. Fissile loadings increase with decreasing amounts of MST in contact with the salt solutions saturated in plutonium and uranium. At MST concentrations bounding those which are planned for the ITP process, expressions for the maximum loadings (wt %) are determined to be 0.29 - 0.20x[MST] for plutonium and 1.8 - 0.29x[MST] for uranium, where [MST] is the concentration of MST in grams/liter. These expressions are valid over the range of MST concentrations from 0.05 to 0.51 g/L and ...
We compared MRSA Select to mannitol-salt agar with 8 μg/ml cefoxitin for the detection of methicillin-resistant Staphylococcus aureus (MRSA) from 6,199 clinical...Full Text Available
Previously we reported that standard oral rehydration salts (ORS) solution is not as effective as a reduced-osmolarity glucose-based ORS for the treatment of children with acute noncholera diarrhoea:...Full Text Available
Proline accumulation in NaCl-treated excised barley (Hordeum vulgare var Larker) leaves was studied. Leaves were treated by placing the cut end in NaCl solutions and allowing the salt...Full Text Available
The objective of this experiment was to determine the effect of dietary grain on calcium homeostasis. Six rumen-fistulated dairy cows with 3 or more previous lactations and no history of parturient...Full Text Available
Development of the engineering technology basis of pyrometallurgical reprocessing is a key issue for industrialization. For development of the transport technologies of molten salt and liquid cadmium at around 500 deg. C, a salt transport test rig and a metal transport test rig were installed in Ar glove box. Function of centrifugal pump and 1/2'' declined tubing were confirmed with LiCl- KCl molten salt. The transport behavior of molten salt was found to follow that of water. Function of centrifugal pump, vacuum sucking and 1/2'' declined tubing were confirmed with liquid Cd. With employing the transport technologies, industrialization applicable electro-refiner was newly designed and engineering-scale model was fabricated in Ar glove box. The electro-refiner has semi-continuous liquid Cd cathode instead of conventional one used in small-scale tests. With using actinide-simulating elements, ...
Results of feasibility experiments for determining the mineral content of individual stains on special Sensitized Paper are presented. The stains were formed on the paper by the impaction of laboratory generated salt water droplets. Of the techniques exam...
It is well known that DNA strands bind to silica surfaces in the presence of high concentrations of chaotropic salts. We developed simple methods to evaluate binding and recovery of DNA on flat...Full Text Available
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
The antibacterial activity of aqueous solutions of paraformaldehyde in concentrations from 0.1 to 0.4% (w/v) is bacteriostatic rather than bactericidal in the presence or absence of ammonium chloride....Full Text Available
A general procedure for stabilization of O2-labile enzymes exploiting "salting out" of oxygen from the microenvironment in the molecular layers immediately adjacent to charged surfaces of polyionic...Full Text Available
...visible damage. (k) Corrosion resistance. Each metal part of a...evidence of salt-spray corrosion resistance equal to or greater than...sample of test metal must show corrosion resistance equal to or better than...
The relationships between soil salinization and the zonal and provincial bioclimatic conditions, the lithological composition of the sediments, and the geomorphic features of the territory have been analyzed for the Southern federal okrug of Russia. It is shown that the lithological and geomorphic conditions (relief, salinity of parent materials, degree of drainage, and the depth of saline groundwater) play an important role in the distribution of salt-affected soils against the background of the more general regularities specified by the climate. The participation of salt-affected soils in the soil cover of the Southern federal okrug increases in the eastward direction from the forest-steppe zone to the semidesert zone in agreement with an increase in the aridity and continentality of the...
Solution and dilution enthalpies of aqueous solutions of potassium diclofenac salt (K_DC) were measured by an isoperibolic calorimeter at 298.15 and 318.5?K. Heat capacities of the solutions with concentrations 0.002?0.09?mol?kg?1 were obtained at the temperature interval of 288.15?318.15?K using a scanning adiabatic microcalorimeter. The virial coefficients were derived from Pitzer?s model, and the excess thermodynamic functions of both the solvent and the solute of the solution were calculated. The concentration and temperature dependencies of thermodynamic characteristics of the solution were analyzed and discussed.
This paper reports on hydrolysis of 10 metal salt aqueous solutions of 6 metal oxides that was conducted in supercritical water. Continuous and rapid production of metal oxide fine particles was achieved by mixing a metal salt aqueous solution with preheated water fed from another line. The reaction time required was less than 2 min. Particle size, morphology, and crystal structure of the obtained metal (hydrous) oxides were examined. Particle size (20 to 600 nm) was different among the system but the size range was relatively narrow in all the cases.
This patent describes a process for preparing poly(aryl ether ketones) by nucleophilic displacement polymerization in the presence of at least one alkali metal base selected from potassium, rubidium or cesium, and fluoride ions, which comprises adding to the polymerization: (a) an effective amount of at least one metal salt selected from lithium, sodium, alkaline earth or lanthanide chloride, bromide, iodide, sulfate, alkyl or aryl carboxylate, cyanide, borate or phosphate to slow or stop advancement of molecular weight and (b) an end-capping agent.
Crystallization points of aqueous solution of the systems M(ClO_4)_2-H_2O (M"2 = Mg"2"+, Ca"2"+, Sr"2"+, Ba"2"+), depending on the salt concentration, were identified by visual-polythermal method. Relying on model notions on the structure of the electrolyte solutions, specific features of strontium perchlorate solubility polytherm and concentration dependence of the relative dynamic viscosity of the salt aqueous solutions are discussed
Capsulation of terbium(III) chloride in porous glass in the amount of 1.5-150 #mu#mole g"-"1 was carried out by impregnation of the glass substrate with variable concentrations of the salt aqueous solutions. Maximum luminosity of terbium(III) chloride in porous glass is found at its concentration of 120 #mu#mole g"-"1, that is close to the corresponding monolayer surface filling. Concentration dependences of terbium(III) luminescence and its quenching by adsorbed water are in agreement with the ideas of molecular fragmentation and uniform distribution of capsulated salt on the substrate surface
This report documents results of a preliminary hazard analysis (PHA) covering the existing Crane Chempump and the new salt well pumping design. Three hazardous conditions were identified for the Chempump and ten hazardous conditions were identified for the new salt well pump design. This report also presents the results of the control decision/allocation process. A backflow preventer and associated limiting condition for operation were assigned to one hazardous condition with the new design.
Enzyme-linked Immunosorbent assay systems for the identification of irradiated egg, pork and chicken was developed. Eggs were irradiated in their shells to 0.5{approx}7kGy. Pork was irradiated to 0.5{approx}3kGy and chicken irradiated to 0.5kGy{approx}5kGy. The most sensitive proteins to irradiation were screened by SDS-PAGE and purified. Ovalbumin from egg, salt soluble protein(p) from pork, and salt soluble protein(c) from chicken showed the most sensitivity to irradiation. To investigate for a practical use in identifying of irradiated egg, pork and chicken, competitive ELISA was performed. The binding activity of ovalbumin to anti-ovalbumin IgG was reduced in a dose-dependent manner by irradiating up to 7kGy, and considerably lowered after irradiating at 7kGy. The concentration of 50% inhibition of ovalbumin to IgG was increased to 1.5(0.5kGy){approx}3.7(7kGy) times in an dose-dependent relationship. The binding activity of ...
A chromium-free conversion coating for magnesium alloys were described. The conversion coating could be obtained when AZ31D magnesium alloy was immersed in a solution containing a manganese salt, phosphate and an inhibitor. Corrosion resistance of the chemical conversion coating was evaluated by anodizing polarization curve and salt immersion. XRD analysis showed that the conversion coating was mainly composed of Mn{sub 3}(PO{sub 4}){sub 2}. The morphology of the coating is observed by using SEM. The effect of electrolyte pH and concentration of inhibitor on coating growth are investigated. (orig.)
Understanding the erosion and deposition rates in a small watershed is important for designing soil and water conservation measures. The objective of this study is to estimate the net soil loss and gain at points with various land use types and landform positions in a small watershed in the Sichuan Hilly Basin of China by the 137Cs tracing technique. Among various land use types, the order of erosion rate was bare rock > sloping cultivated land > forest land. The paddy field and Caotu (a kind of cultivated land located at the foot of hills) were depositional areas. The erosion rate under different landform was in this order: hillside > saddle > hilltop. The footslope and the valley were depositional areas. The 137Cs technique was shown to provide an effective means of documenting the spatial distribution of soil erosion and deposition within the small watershed.
Pd/sub 2/Si formation at the Pd-Si interface induced by irradiation with ions having a wide range of nuclear energy of deposition density has been investigated. It is found that the thickness of the silicide layer formed by irradiation is proportional to the ion fluence for irradiation with ions having low energy-deposition densities, while it is proportional to the square root of the fluence for irradiation with ions having energy-deposition densities. The results indicate that Pd/sub 2/Si formation is reaction limited when the energy-deposition density at the interface is low and is diffusion limited when it is high. The results are compared with the phenomenological theory developed by Horino et al. and it is shown that such a dependence of the limiting processes on the energy depositon density is induced when the diffusion is thermally activated while the reaction at the interface is ...
Anti-reflective coatings made with Teflon AF2400 had the highest damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, maintained the bulk optical properties of a high transmittance from 200 nm to 1600 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.
A model is described for simulating thermal hydraulic and chemical conditions within fuel crud deposits. Heat transfer takes place by wick boiling in which water flows through the porous deposit and evaporates into steam at the surface of chimneys. The transport and chemistry of dissolved species within the deposit is also modelled. This chemistry includes the equilibrium chemistry of Li/boric acid species, the equilibrium chemistry of Fe/Ni species and the radiolysis chemistry of water. The unique feature of this model is that the chemistry is coupled to the thermal hydraulics via the increase in the saturation temperature with the concentration of dissolved species. This has a profound effect on evaporative heat transfer within thick deposits, leading to conditions that explain the precipitation of LiBO{sub 2} and the possible formation of bonaccordite. The model helps understand several crud scrape ...
An experimental technique has been developed to examine the interaction between deformation and the exposure of certain high temperature structural alloys to oxidizing molten salt environments. The experimental program involved performing a series of long-term tensile tests over a wide range of strain rates. Fracture strain reduction in area and ultimate strength (UTS) were monitored as parameters indicative of an alloy's susceptibility to environmental degradation. For Incoloy Alloy 800 tested at 600/sup 0/C in the salt medium and at initial strain rates between 2 x 10/sup -7/ sec/sup -1/ and 1 x 10/sup -5/ sec/sup -/1 no appreciable loss of ductility, as measured by reduction in area, was observed relative to control specimens tested in air at the same temperature and strain rates. Similarly, fracture strain and UTS were essentially unaffected by exposure to the oxidizing environment. The structure of the oxide film formed by contact ...
The carbon dioxide capture potential of amine amino acid salts (AAAS), formed by mixing equinormal amounts of amino acids; e.g. glycine. B-alanine and sarcosine, with an organic base; 3-(methylamino)propylamine (MAPA), was assessed by comparison with monoethanolamine (MEA), and with amino acid salt (AAS) from amino acid neutralized with an inorganic base; potassium hydroxide (KOH). Carbon dioxide absorption and desorption experiments were carried out on the solvent systems at 40{sup o}C and 80{sup o}C respectively. Experimental results showed that amine amino acid salts have similar CO{sub 2} absorption properties to MEA of the same concentration. They also showed good signs of stability during the experiments. Amino acid salt from an inorganic base, KOH, showed lower performance in CO{sub 2} absorption than the amine amino acid salts (AAAS) mainly due to a lower equilibrium ...
The importance of indigenous soil Mn level on plant Mn uptake from metal salt or sewage sludge amended soils was investigated. Twelve soil materials, six surface and six subsurface, were amended with either varying rates of a composite of Cd, Cu, Ni, and Zn sulfate salts, equivalent to the total of these metals present in a digested sewage sludge (Washington, DC) at rates of 0 to 896 dry metric tons/ha or with the sludge itself, at 224 dry metric tons/ha. Corn (Zea mays L.) was grown in the greenhouse for 30 days, 1 year after amendment application. Two pH levels of about 5.5 and 6.5 were maintained during the experiment on the metal salt amended soil materials. Plant tissue Mn levels increased with the application of Cd, Cu, Ni, and Zn (in combination) as metal salts or as sewage sludge over the range of soil materials used. The amount of increase with a given increase in applied metals was greater for ...
The liquefaction reaction system of an NEDOL process coal liquefaction 1t/d PSU was opened and checked to investigate the cause of the rise of differential pressure between liquefaction reactors of the PSU. The liquefaction test at a coal concentration of 50 wt% using Tanito Harum coal was conducted, and it was found that the differential pressure between reactors was on the increase. By the two-phase flow pressure loss method, deposition thickness of deposit in pipelines was estimated at 4.4mm at the time of end operation, which agreed with a measuring value obtained from a {gamma} ray. The rise of differential pressure was caused by deposit formation in pipelines connecting reactors. The main component of the deposit is calcite (CaCO3 60-70%) and is the same as the usual one. It is also the same type as the deposit on the reactor wall. Ca in coal ash is concerned with this. To ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO_2 substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio I(111)/I(200) reaches its maximum value indicating a strong left-angle 111 right-angle texture, while the impurity concentration and resisitivity are minimum. The correlation ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. ...
Ion bombardment during deposition can significantly modify the film properties. In the partially ionized beam deposition, ions derived from the depositing material, i.e., the self-ions, are used during deposition. Cu films were deposited on SiO{sub 2} substrates at room temperature using 1% Cu self-ions with an energy ranging between 0--4 keV. We studied the microstructures of the Cu films using x-ray diffraction and transmission electron microscopy, measured the impurity level inside the films using secondary ion mass spectrometry, and performed the resistivity measurements using a four point probe. The results indicate that there is an optimum ion energy around 2 keV at which, the integrated x-ray intensity ratio {ital I}(111)/{ital I}(200) reaches its maximum value indicating a strong {l angle}111{r angle} texture, while the impurity concentration and resisitivity are minimum. ...
Cathodic arc deposition is an established and industrially applied technique for the formation of nitrides (e.g. TiN); it can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. ...
The dry deposition of pollutants can be calculated from the concentration of pollutants in the atmosphere and deposition velocity. To calculate deposition velocity, turbulence parameters such as friction velocity and Monin-Obukhov length are used. However, due to the difficulties in observation of turbulence parameters, usually mean values of wind speed and temperature observed using conventional meteorological instruments are used to estimate the dry deposition. The dry deposition velocity is the function of aerodynamic resistance (R{sub a}), sublayer resistance (R{sub b}), surface resistance (R{sub c}). R{sub a} and R{sub b} are calculated from turbulence parameters and R{sub c} is related to surface characteristics. The purpose of the present study is to compare the dry deposition obtained using the data sets of mean values and turbulence parameters measured ...
Sputter-deposited tantalum (Ta) and reactively sputter-deposited Ta-nitride films were studied with respect to the passivation capability against copper (Cu) oxidation in thermal O{sub 2} ambient. A 200 {angstrom} Ta or Ta-nitride film was sputter-deposited on a 2,000 {angstrom} Cu film using a Ta target in an Ar/N{sub 2} gas mixture. With Ta passivation, Cu was not oxidized at temperatures up to 400 C, which can be further improved by using passivation of an amorphous Ta-nitride film deposited in an appropriate condition. The absence of long-range defects in the Ta-nitride film was presumably responsible for this improvement. However, sputtering-induced surface damage by excess N{sub 2} in the sputter gas mixture may reduce the passivation capability of Ta-nitride films. When the passivated Cu was oxidized, the Cu oxides always resided in the top surface region. That is, in the oxidation process, Cu ...
A "hemispheres-in-cell" geometry is provided for prediction of colloid retention during transport in porous media. This new geometry preserves the utilities provided in the Happel sphere-in-cell geometry; namely, the ability to predict deposition for a range of porosities, and representation of the influence of neighboring collectors on the fluid flow field. The new geometry, which includes grain to grain contact, is justified by the eventual goal of predicting colloid deposition in the presence of energy barriers, which has been shown in previous literature to involve deposition within grain to grain contacts for colloid:collector ratios greater than approximately 0.005. In order to serve as a platform for predicting deposition in the presence of energy barriers, the model must be shown capable of quantitatively predicting deposition in the absence of energy barriers, which is a ...
The properties of polycrystalline (Ti, Al)N coatings deposited on non-nitrided, classically plasma-nitrided and low pressure plasma-nitrided AISI H11 steel samples were investigated. The plasma deposition and low pressure plasma nitriding were performed in a Z700-LH magnetron sputter ion plating unit, while a separate unit was used for plasma nitriding of specimens at a pressure of several millibars. The (Ti, Al)N coating was deposited onto all the samples using the same equipment as for the plasma deposition and low pressure plasma nitriding. For the characterization of the composite structures, the following methods were used: scratch test, X-ray diffraction analysis, scanning electron microscopy, scanning tunnelling microscopy and microhardness testing. It was found that plasma nitriding prior to coating deposition strongly affects the growth and properties of hard coatings, such ...
A thin film microoxidation test utilizing the concept of the Lubricant Stability Map has been used to study the effect of temperature on deposit formation by lubricants on upper piston locations of low heat rejection engines. The stability maps were established for two formulated lubricants in this study. These two lubricants were also evaluated in a series of engine tests with various piston temperatures. The deposition phenomena observed in the engine tests have been adequately simulated and described by the stability maps. It is concluded that lubricants at upper piston locations are under a thin film condition similar to that achieved by the thin film microoxidation test. The deposit formation trend is determined by the volatility, thermal stability, and oxidative stability of the base stock. Additives have little effect on deposit formation at very high temperatures. A combined consideration of all ...
The localized Pt deposition on Si by 30 keV Ga"+ focused ion beam (FIB), 10 keV electron beam (EB) or dual beams (FIB and EB) using precursor gas has been compared by analysis using a 300 keV Be"2"+ microprobe with a beam spot size of 80 nm. The distribution of deposited Pt, Ga from the ion beam itself, and C from the precursor gas was obtained at and nearby the deposited areas by micro-RBS spectra and RBS mapping. All of the beam processed areas showed a uniform Pt distribution at the deposited areas. The amount of Pt atoms increased with the increase in ion or electron dose due to the decomposition of precursor gas. The thickness of Pt layer by EB is considerably less than that by FIB due to the reduced deposition rate. Ga atoms from the center of processed areas partly redeposited at and nearby the FIB processed areas within #approx#3 #mu#m. The Ga incorporation by dual beam ...
Applying the theory of depositional system, the depositional facies and depositional systems of the Zhiluo Formation in Dongsheng area are systematically analysed, and the authors proposed that sediments of the Zhiluo Formation are of fluvial facies, and streams of the Zhiluo time experienced three evolution stages, namely: the early braided stream, the middle low sinuosity meandering stream and the late high sinuosity meandering stream. Based on features of paleoclimatic evolution, the Zhiluo Formation is divided into two lithological members. The lower lithological member consists of sediments of braided and low sinuosity meandering streams under humid-ward paleoclimatic conditions forming grey sedimentary formation. The upper member is composed of sediments of meandering streams under arid-hot paleoclimatic conditions representing complex-colored (mainly red) sedimentary formation. It is suggested that uranium ...
The Salt Decontamination Demonstration confirmed that the precipitation process could be used for large-scale decontamination of radioactive waste sale solution. Although a number of refinements are necessary to safely process the long-term requirement of 5 million gallons of waste salt solution per year, there were no observations to suggest that any fundamentals of the process require re-evaluation. Major accomplishments were: (1) 518,000 gallons of decontaminated filtrate were produced from 427,000 gallons of waste salt solution from tank 24H. The demonstration goal was to produce a minimum of 200,000 gallons of decontaminated salt solution; (2) cesium activity in the filtrate was reduced by a factor of 43,000 below the cesium activity in the tank 24 solution. This decontamination factor (DF) exceeded the demonstration goal of a DF greater than 10,000; (3) average strontium-90 activity in the ...
Using a new simulative technique developed by us, we systematically investigated new ternary or quaternary molten salt systems, which are based on LiF-LiCl, LiF-LiBr, and LiCl-LiBr binary systems, for use as electrolytes in thermal batteries, and evaluated their ionic conductivities and melting points experimentally. It was confirmed experimentally that LiF-LiBr-KF (melting point: 425^oC, ionic conductivity at 500^oC: 2.52Scm^-^1), LiCl-LiBr-KF (405^oC, 2.56Scm^-^1), LiCl-LiBr-NaF-KF (425^oC, 3.11Scm^-^1), LiCl-LiBr-NaCl-KCl (420^oC, 2.73Scm^-^1), and LiCl-LiBr-NaBr-KBr (420^oC, 2.76Scm^-^1) meet our targets for both melting point (350-430^oC) and ionic conductivity (2.0Scm^-^1 and higher at 500^oC). A single cell using the newly developed LiCl-LiBr-NaCl-KCl molten salt as an electrolyte w...
A a result of its former role as a producer of nuclear weapons components, the Rocky Flats Environmental Technology Site (RFETS), Golden, Colorado accumulated a variety of plutonium-contaminated materials. When the level of contamination exceeded a predetermined level (the economic discard limit), the materials were classified as residues rather than waste and were stored for later recovery of the plutonium. Although large quantities of residues were processed, others, primarily those more difficult to process, remain in storage at the site. It is planned for the residues with lower concentrations of plutonium to be disposed of as wastes at an appropriate disposal facility, probably the Waste Isolation Pilot Plant (WIPP). Because the plutonium concentration is too high or because the physical or chemical form would be difficult to get into a form acceptable to WIPP, it may not be possible to dispose of a portion of the residues at WIPP. The pyrochemical salts are ...
Influence of alkali elements on formation, composition, solubility and region of stability of complex hafnium sulfates, separated in the HfO"2-H"2SO"4-Me"2SO"4-H"2O (Me-Na, K, Rb, Cs and NH"4 group) systems is studied. In all cases hafnium forms the complex sulfates of three types differing by basicity or ratio HfO"2:SO"3 1:1, 1:1.5, 1:2. Three basic and three medium sulfates are crystallized in the systems with sodium; with rubidium, cesium and ammonium - two basic and two medium sulfates and with potassium - two basic and one medium salts. Anhydrous salts do not form in the investigated systems. Potassium salt approximately 0.3% according to HfO"2 is characterized by minimum solubility from the salts of 2HfOSO"4x(1-3)Me"2SO"4x(4-6)xH"2O while solubility of the same salts with rubidium, cesium and sodium increases from (0.25-1.0); (0.5-1.5) till (1.0-5)% according to HfO"2 ...
Axial offset anomaly (AOA) is caused by the deposition of crud on the fuel cladding of a PWR. When significant levels of crud build up on the cladding, boron can accumulate in the pores of the crud as a concentrated solution or solid phase, and cause the flux depression. Numerous studies have been conducted on the primary water chemistry to reduce the amount of crud in the primary circuit to avoid radioactivity buildup and unexpected power transition in the plant. However, experiments on the crud are restricted in the laboratory because the crud is a highly radioactive material. The objective of this study is to develop a test method for simulating the deposition of crud in a nuclear power plant
High power and particle deposition on target materials are encountered in many applications including magnetic and inertial fusion devices, nuclear and high energy physics applications, and laser and discharge produced plasma devices. Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the Tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination.
Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.
Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.
The Rosebel gold district is hosted in a Paleoproterozoic greenstone belt of the Guiana Shield and has many characteristics that enable classification of the ores as an orogenic gold deposit. Host rocks have undergone several phases of deformation. However, gold deposition occurred late in the structural history of the belt, and is considered part of a late regional metallogenic event with respect to the geotectonic evolution of the Guiana Shield. Economic gold mineralization is hosted in felsic to mafic volcanic rocks and two sedimentary successions that are differentiated into turbiditic and arenitic depositional packages. The detailed lithostratigraphic characterization and the geochemistry enable the correlation of the local rock types with the Paramaka, the Armina, and the Rosebel for...
In this study, liquid flame spray (LFS) was used to produce titania, silver and silver-titania deposits of nanoparticles. Titanium(IV)ethoxide (TEOT) and silver nitrate in ethanol solutions were used as precursors and sprayed into turbulent hydrogen-oxygen flame. Production rates of 1.5-40 mg/min of titania were used with silver additions of 1, 2, 4, and 8 wt% compared to titania. Nanoparticle deposits were collected by thermophoretic sampling at six different axial distances from the flame torch head: 3, 5, 10, 12, 15, and 20 cm, of which the all but the last one occurred inside the flame. The deposit samples were analysed by TEM and SAED analysis. The powder samples of the particles were also collected by electric precipitator to XPS and specific surface area analysis. Particle size and effective density after the flame in the aerosol were analysed with SMPS and ELPI. The results from the previous studies i.e. controlling ...
There is increasing demand to functionalize meso- and nano-porous materials by coating and make the porous substrate biocompatible or environment friendly. However, coating on a meso-porous substrate poses great challenges, especially if the pore aspect ratio is high. In the current work the pulsed laser deposition (PLD) method is used for coating Ni{sub 3}Al-based meso-porous membranes with diamond-like carbon (DLC) layers of high thickness homogeneity and adhesion. (orig.)
ABSTRACT Shallow-lacustrine delta deposits of the Upper Triassic Yanchang Formation form the most important petroleum reservoir sandstone units in the Ordos Basin, China. Recent hydrocarbon exploration and outcrop studies demonstrated that shallow-lacustrine sand-rich deltas developed extensively along the gentle flanks and central part of the basin. The vertical succession of facies indicates that the Yanchang Formation records the entire lacustrine life cycle of the Late Triassic Ordos Basin. Four third-order transgressive-regressive cycles and two larger shallow-lacustrine deltaic cycles have been recognized. A process-based depositional model, derived in part from the modern Ganjiang delta in Poyang Lake, China, is used to infer the origins of the sand-rich lacustrine delta deposits. S...
The workshop topics consist of FERS, FEGLI, FEHBP, Disability, Deposit/Redeposit ; TSP, Annual/Sick Leave, Annuity Calculation, Best Date to Retire, COLA's, ...
The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).
Oil shales of the US represent a tremendous store of potential oil. Most of the deposits are relatively unknown and warrant additional investigation. The summary presented cannot hope to cover all of the deposits. Information about them is usually available only locally. However, the 3 best known deposits - the Green River formation, the Devonian black shales, and the retort member of the Phosphoria formation - represent well over 2 trillion bbl (300 x 10/sup 12/ ton) of potential oil in place. This is an oil resource large enough to supplement quite adequately the US petroleum supply, to extend the time available for realigning our energy supply mixes, and to help reach a satisfactory solution to our current energy dilemma. The concentrated resource in the Green River formation is obviously the next most feasible source of oil. If it cannot be developed, all the other deposits will have to wait until ...
Obesity is characterized by the abnormal or excessive deposition of fat in the adipose tissue. Its consequences go far beyond adverse metabolic effects on health, causing an increase in oxidative stress,...Full Text Available
... ge aircraft engines (geae) has taken to development an induction plasma deposition (ipd) processing method for the fabrication of ti6242/sic mmc ...
The distribution of Lipiodol in the liver and lungs following arterial or portal injection was studied in normal (n=55) and cirrhotic rats (n=20). Using magnified xeroradiography and radioisotope labeled tracers, it was found that Lipiodol was deposited mainly in the liver and lung after either arterial or portal administration. In control rats after arterial injection, deposits in the lung peaked after 2 hours and gradually declined over 48 hours; whereas after portal injection, the deposit steadily increased for 48 hours. Twenty-five percent of cirrhotic rats demonstrated a Lipiodol-induced miliary pattern in the lung. An increased number of portosystemic shunts in cirrhotic rats was also noted. These results suggest that cirrhosis of the liver may be a potential risk factor for developing pulmonary complications after Lipiodol administration. (orig.).
Cold spray was employed as a novel low temperature approach to deposit titanium dioxide (TiO{sub 2}) photocatalytic film. The film microstructure was characterized using X-ray diffraction and scanning electron microscopy. The photocatalytic performance was examined through acetaldehyde degradation under ultraviolet illumination. Results showed that TiO{sub 2} film was successfully deposited on substrate surface through cold spray. The film thickness reached up to 15 {mu}m. The film presented a rough surface and porous structure. Owing to the low temperature of spray powder, no phase and particle size changes occurred to TiO{sub 2} during deposition. It was found that the cold-sprayed TiO{sub 2} film was active for photodegradation of acetaldehyde.
Focused Ion Beam (FIB) repairs and modifications to integrated circuits have been somewhat limited in the past due to the physical limitations imposed by the nodes of interest being buried under metal layers, the need for multiple layers of FIB generated interconnects, and the like. With the advent of FIB deposited INSULATOR materials, integrated circuit modifications can now be much more complex. The two primary goals of this project were (1) to determine the appropriateness of FIB insulator deposition for aiding FIB connections to metal nodes buried under power busses, and (2) development of a technique to do this. The work presented in this paper includes the development and characterization phases of adding INSULATION DEPOSITION to a FEI 611 FIB system, the problems encountered, their work around, and the aforementioned application of this technology.
A procedure based on electrophoretic deposition (EPD) was developed to coat metal plates with powder catalysts. The method was tested on stainless-steel plates with three Ni-based catalysts for the steam reforming of ethanol. The catalysts (Ni/La2O3/g-Al2O3) contained 15% Ni and 8% La, and were prepared using three types of g-alumina with different textural properties. The powder catalysts were suspended in isopropanol, and EPD deposition was performed with a voltage of 100V and a distance between electrodes of 2cm. Deposition time was varied between 3 and 7min, which gave a thickness of the catalyst layer from around 30 to 100mm. The morphology of the catalyst layer was dependent on the textural characteristics of the g-Al2O3 used to prepare the catalyst. The activity of the catalyst plat...
Indium sulfide thin films were deposited onto indium-tin-oxide coated glass substrate by electrochemical deposition from an aqueous solution containing In2 (SO4) 3 and Na2S2O3. The deposition conditions were optimized on the basis of data obtained by scanning electron microscope, Auger electron spectroscopy and optical transmission measurements. Furthermore, the photosensitivity of the films was observed by means of photoelectrochemical measurements, which confirmed that the indium sulfide showed n-type conduction. The X-ray diffraction and Raman studies revealed that the as-grown films were amorphous or nanocrystalline in nature and became polycrystalline In2S3 after annealing.
The corrosion behavior of the sputter-deposited amorphous or nanocrystalline W-Nb alloys is studied in 10% NaCl, 0.1 and 1 M NaOH solutions at 24 deg. C, open to air using immersion tests and electrochemical measurements. Niobium metal acts synergistically with tungsten in enhancing the corrosion resistance of the W-Nb alloys so as to show lower corrosion rates than the corrosion rates of the alloy-constituting elements in almost all examined solutions. Corrosion rates of W-Nb alloys are about more than one order of magnitude less than that of the sputter-deposited tungsten and even lower than that of sputter-deposited niobium. The stability of the anodic passive films formed on the W-Nb alloys increase with niobium content.
Dosimetry parameters such as deposition, clearance, retention, and translocation and dissolution of inhaled particles in and to different lung compartments may be important for the persistence of particles...Full Text Available
The density of corn pollen on leaves of milkweed plants inside and outside of cornfields was measured in several studies from different localities. The purpose was to obtain a representative picture...Full Text Available
This paper reports on a series of experiments performed to examine the ability of ion beam assisted thermal deposition to produce good adhesion of Au metallization on GaAs left-angle 100 right-angle substrates. A study of the influence of Ar ion-assisted thermal deposition of the Au films as well as in situ pre-sputtering of the GaAs surface with low-energy Ar ions prior to thermal deposition, shows that strong adhesion can be achieved without resorting to chemical cleaning. The substrate temperature and the relative flux of Ar ions to incident Au atoms were varied in order to correlate these parameters with film adhesion. The interfaces of films processed under these various conditions were examined by XTEM, RBS and XPS. Orientation texture was studied by x-ray diffraction (XRD).
The method is related to hydrodynamic methods for studying wells and may be used in the prospecting and mapping of gas and gas condensate deposits and formations. The method consits of drilling exploratory wells and measurement of the physical parameters of the stratum liquid. The piezometric levels are periodically determined simultaneously in all the observation wells during a change in the atmospheric pressure, and the presence of a remoteness of the gas deposit from the well is judged from the size of the increments in the piezometric levels intime. The determinations of the piezometric levels in the wells are conducted during an abrupt change in atmospheric pressure, for instance, during the replacement of a cyclone by an anticyclone or the reverse. The atmospheric pressure is measured by a barograph, while the piezometric levels are measured by high precision level meters or pressure gauges of low pressure. The method increases the ...
The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...
We improve the steady-state ab initio laser theory (SALT) of Tureci et al. by expressing its fundamental self-consistent equation in a basis set of threshold constant flux states that contains the exact threshold lasing mode. For cavities with non-uniform index and/or non-uniform gain, the new basis set allows the steady-state lasing properties to be computed with much greater efficiency. This formulation of the SALT can be solved in the single-pole approximation, which gives the intensities and thresholds, including the effects of nonlinear hole-burning interactions to all orders, with negligible computational effort. The approximation yields a number of analytic predictions, including a "gain-clamping" transition at which strong modal interactions suppress all higher modes. We show that the single-pole approximation agrees well with exact SALT calculations, particularly for high-Q cavities. Within this range of validity, ...
The single-electrode capacitance of a nano-porous carbon electrode used as an electric double layer capacitor was measured. The charged state of the electrolyte ion was discussed from the results. Single-electrode capacitance was not proportional to the specific surface area of the electrode. This implies that the whole surface of the electrode is not effective for the formation of an electric double layer. It is considered that edge orientation of the carbon structure would give a dominant contribution to capacitance. For measurements with aqueous solutions of various electrolytes, capacitance was about the same value for each salt compound. For aqueous acid solution, on the other hand, capacitance was twice to three times as large as that for salt compounds. This difference, however, became negligibly small if the concentration of electrolyte solution was lowered. Taking account of the hydrated ionic radius of each ion, it was considered that ...
As the surroundings of objects of oil exploration grow more complicated, seismic survey methods have turned 3-dimensional and, in this report, several models are examined using the 3-dimensional simulation technology. The result obtained by the conventional wave tracking method is different from actual wavefields, and is unrealistic. The difference method among the fullwave modelling methods demands an exorbitantly long computation time and high cost. A pseudospectral method has been developed which is superior to the difference method, and has been put to practical use thanks to the advent of parallel computers. It is found that a 3-dimensional survey is mandatory in describing faults. After examining the SEG/EAGE Salt model, it is learned that the salt is well-developed and that 3-dimensional depth migration is required for sub-salt exploration. It is also found through simulation of the EAGE/S Overthrust model, which is ...
A trans-uranium (TRU) fuel should be manufactured and loaded in transmutation systems in order to transmute the long-lived TRU nuclides into short-lived ones. However, since all of the TRU nuclides are not completely transmuted in one cycle lifetime in transmutation systems, the spent TRU fuel has to be treated to recover the long-lived radionuclides or fuel matrix materials. One concept to manufacture TRU fuel for transmutation is to recover uranium from TRU and molten salt. If this type of fuel is adopted for transmutation, uranium could also be an objective material to be recovered and recycled. Since electrowinning is a promising technology to be employed for the recovery of uranium from fuel materials, some experimental work of electrowinning using anode of Cd-Li alloy was carried out in this study. The basic salt chosen was a mixture of LiCl-KCl which has an eutectic point at 357 .deg. C.
A trans-uranium (TRU) fuel should be manufactured and loaded in transmutation systems in order to transmute the long-lived TRU nuclides into short-lived ones. However, since all of the TRU nuclides are not completely transmuted in one cycle lifetime in transmutation systems, the spent TRU fuel has to be treated to recover the long-lived radionuclides or fuel matrix materials. One concept to manufacture TRU fuel for transmutation is to recover uranium from TRU and molten salt. If this type of fuel is adopted for transmutation, uranium could also be an objective material to be recovered and recycled. Since electrowinning is a promising technology to be employed for the recovery of uranium from fuel materials, some experimental work of electrowinning using anode of Cd-Li alloy was carried out in this study. The basic salt chosen was a mixture of LiCl-KCl which has an eutectic point at 357 .deg. C
Nanocomposites containing polyethylene (PE) and montmorillonite clay organically modified (OMMT) with quaternary ammonium salts were obtained via direct melt intercalation. A montmorillonite sample from the Brazilian state of Paraiba was treated with four different types of quaternary ammonium salts. After the treatment, the powder was characterized by X-ray diffraction and scanning electron microscopy. The dispersion and morphologies of OMMT within PE were investigated by X-ray diffraction and transmission electron microscopy. The results revealed the formation of intercalated montmorillonite layers in the PE matrix. The thermal stability and flammability of the PE/montmorillonite clay nanocomposites were measured by thermogravimetry and horizontal burning tests for HB classification, Underwrites Laboratories (UL 94), respectively. It was shown that the samples do not degrade at the processing temperature. By adding only 3 wt.% ...
The United States Air Force School of Aerospace Medicine (USAFSAM) tests the quantitative fit of masks which are worn by military personnel during nuclear, biological, and chemical warfare. Subjects are placed in a Dynatech-Frontier Fit Testing Chamber, salt air is fed into the chamber, and samples of air are drawn from the mask and the chamber. The ratio of salt air outside the mask to salt air inside the mask is called the quantitative fit factor. A motion-time study was conducted to evaluate the efficiency of the layout and work method presently used in the laboratory. A link analysis was done to determine equipment priorities, and the link data and design guidelines were used to develop three proposed laboratory designs. The proposals were evaluated by projecting the time and motion efficiency, and the energy expended working in each design. Also evaluated were the lengths of the equipment links for each proposal, and ...
The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from brine at the boiling point exhibited a near ...
The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from brine at the boiling point exhibited a near ...
A series of spinel Li4Ti5O12 samples were synthesized via a composite molten-salt method (CMSM) using the mixtures of LiCl and KCl with different L values (L is defined as the molar ratio of LiCl:KCl) as the reaction media. It is found that the melting point of the composite molten salt can effectively influence the formation of particles, and leads to different electrochemical performances of the as-prepare Li4Ti5O12. The investigations of X-ray diffraction (XRD), particle size distribution (PSD), Brunauer-Emmet-Teller (BET) surface area, and scanning electron microscopy (SEM) indicate that the as-prepared Li4Ti5O12 with L = 1.5 is a pure phase, and has uniform homogeneous octahedral shape particles, rather narrow PSD, and high BET surface area. Electrochemical tests show that the optimized Li4Ti5O12 with L = 1.5 has an initial discharge capacity of 169 mAh g-1 and an initial charge-discharge efficiency of 94% at 0.2 C rate, and achieves good ...
A series of spinel Li4Ti5O12 samples were synthesized via a composite molten-salt method (CMSM) using the mixtures of LiCl and KCl with different L values (L is defined as the molar ratio of LiCl:KCl) as the reaction media. It is found that the melting point of the composite molten salt can effectively influence the formation of particles, and leads to different electrochemical performances of the as-prepare Li4Ti5O12. The investigations of X-ray diffraction (XRD), particle size distribution (PSD), Brunauer-Emmet-Teller (BET) surface area, and scanning electron microscopy (SEM) indicate that the as-prepared Li4Ti5O12 with L=1.5 is a pure phase, and has uniform homogeneous octahedral shape particles, rather narrow PSD, and high BET surface area. Electrochemical tests show that the optimized...
Liquid-liquid extractive separation of lithium isotopes was carried out in order to investigate the fluctuation of separation factors (a) as a function of salt concentrations in an aqueous phase. Two equations for separation factor (a_o_b_s) as a function of the concentration were introduced; one for the diluted region, and another for the concentrated region. In the former solution where hydrated lithium ions are predominant, 1n a_o_b_s = Ac + B, and in the latter where ion-pairs with anions are predominant, 1n a_o_b_s = Dc + E(c - F)"1"/"3 + G. Some guidelines are derived from the salt-specific constants A, B, D, E, F and G. The heavier isotopes are inclined to be in the more hydrated state in the diluted solution, while the lighter isotopes tend to be in a less hydrated state. In the concentrated solution, heavier isotopes are more likely to be in ion-pair form. Ionic association occurs from the lower concentration in the order of LiI < ...
Hydrolysis of olive oil by Chromobacterium viscosum lipase was studied in a reverse micellar system of a anionic surfactant Aerosol OT (AOT) and isooctane. Different methods of solubilization of the micellar system afford specific dependence of enzymatic activity of the lipase on the water content in the micelles. In an injection method, water content is controlled by the amount of injected water, which determines the micelle size and hydrophobicity of the micelle without salt addition and changes reversibly the conformation of lipase corresponding to the change of lipase activity. The activity reaches the maximum at a water content (water/AOT)of 7. In a phase transfer method, water content is determined by salt concentration in the aqueous phase in contact with micelles and the water content corresponding to the maximum activity is 12 to 13, below which the activity decrese drastically. Addition of taurodeoxycholic acid to the AOT micelles ...
The goal of this work is to study the effect of the aqueous medium pH on the two-phase equilibrium behaviour of the aqueous {1-butyl-3-methylimidazolium bromide ([C4mim]Br)+potassium citrate} system in order to obtain further information about the salting-out effect produced by the addition of a kosmotropic salt to an aqueous solution of a hydrophilic ionic liquid (IL). For this purpose the phase diagrams and the liquid-liquid equilibrium (LLE) data of the {[C4mim]Br+potassium citrate} aqueous two-phase system (ATPS) were determined experimentally at different pH values. Four medium pH values (5.00, 6.00, 7.00 and 8.00) were assayed at T=298.15K. The effect of pH on the ATPS-promoting capability of citrate anions in the aqueous [C4mim]Br solutions was explained based on the structural hydr...
In order to effectively recover uranium, rotation speed of solid cathode was examined, and effect of uranium concentration and current density on electrodeposition were confirmed. And the potentiostatic and galvanostatic electrorefining experiments were conducted. Element used in the experiments were Zr, Nd, La chlorides. The reduction potentials of chlorides metals on liquid Cd cathode were measured by cyclic voltammetry experiments. The electrowinning experiments were performed in order to recover small amounts of uranium in salt. Experimental set-up for the batch type reductive extraction experiments were developed and installed. On the base of experimental results of batch type, multi-stage extraction equipment was set-up, and optimum number of stage and recover yield were measured. In the oxidative extraction study is examine selective separation behavior of the rare earth metals from alloy composed of actinide and lanthanide metals to determine the effective ...
NREL's Solar Advisor Model (SAM) is employed to estimate the current and future costs for parabolic trough and molten salt power towers in the US market. Future troughs are assumed to achieve higher field temperatures via the successful deployment of low melting-point, molten-salt heat transfer fluids by 2015-2020. Similarly, it is assumed that molten salt power towers are successfully deployed at 100MW scale over the same time period, increasing to 200MW by 2025. The levelized cost of electricity for both technologies is predicted to drop below 11 cents/kWh (assuming a 10% investment tax credit and other financial inputs outlined in the paper), making the technologies competitive in the marketplace as benchmarked by the California MPR. Both technologies can be deployed with large amounts of thermal energy storage, yielding capacity factors as high as 65% while maintaining an optimum LCOE.
Abstract The salts [Cnmim]2[Mo6Cl14] (mim = methylimidazolium; n = 4, 6, 12, 16, 18) have been obtained by reaction of CnmimCl with MoCl2. Thermal analysis shows the melting point decreases with increasing alkyl chain length of the cation. The imidazolium chloromolybdates(II) with n = 6-18 decompose above 340 C; [C18mim]2[Mo6Cl14] is thermally stable up to 390 C. All compounds are insensititve to the constituents of the atmosphere. Of the higher melting salts [Cnmim]2[Mo6Cl14] (n = 4, 6), high-quality single crystals could be obtained. Single-crystal X-ray structural analyses clearly show that the cluster complex anion [Mo6Cl14]2- has an electron-precise octahedral {Mo6} cluster. For [C4mim]2[Mo6Cl14], two polymorphs differing in the cation alkyl-side-chain conformation were obtained. The ...
Simple correlations and corresponding nomographs are presented, which express the maximum useful heat received from salt-gradient solar ponds throughout the year or during a specified season of the year, and the corresponding optimum depth of the nonconvective zone in terms of the thickness of the upper convective zone and the temperature under which the maximum useful heat is received. The correlations are valid for the Athens (Greece) area or for regions with a similar climate, because solar radiation and ambient temperature values for Athens have been employed, obtained by a statistical process of hourly measurements over a period of about 20 years. For other climates, it is easy to develop similar correlations using the same methodology, Development of the proposed correlations is based on a method, which simulates the transient operation of the salt-gradient pond using finite-differences, and calculates the useful heat received hourly ...
The rate of the oxygen-exchange reaction in an aqueous solution of a heterocyclic oxygen compound, 2,4,6-trimethylpyrylium perchlorate, was quantitated. The /sup 18/O isotope effect in /sup 13/C NMR spectroscopy affords a direct, continuous, and relatively simple analysis of the reaction and was used to obtain data on the incorporation of /sup 18/O from solvent H/sub 2//sup 18/O into the pyrylium salt. Due to the low solubility of this salt in aqueous solutions, 2,4,6-trimethyl(2-/sup 13/C)pyrylium perchlorate and 2,4,6-trimethyl(2,6-/sup 13/C/sub 2/)pyrylium perchlorate were synthesized to facilitate the acquisition of the data on an NTC-200 spectrometer operating at 50.31 MHz. Upon incorporation of /sup 18/O into the pyrylium salt, the /sup 13/C NMR signal of the directly bonded carbon atom is shifted upfield 0.038 ppm. A /sup 13/C isotope effect is also detected in the doubly /sup 13/C-enriched pyrylium ...
The synthesis and properties of various 1,2,4,5-tetrazine explosives and energetic materials are described. These are the nitrate and perchlorate salts of 3,6-diguanidino-1,2,4,5-tetrazine, the nitrate and perchlorate salts of 3,6-diguanidino-1,2,4,5-tetrazine-1,4-di-N-oxide, 3,6-bis(1H-1,2,3,4-tetrazol-5-ylamino)-1,2,4,5-tetrazine and its 1,4-di-N-oxide derivative, 3,3'-azobis(6-amino-1,2,4,5-tetrazine) and its oxidation products. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
A new technique has been developed for improving corrosion resistance on magnesium alloys. Specimens of AZ31 magnesium alloy were dipped into molten salt of NaBF{sub 4} at 723 K for various times, and then cooled, rinsed with water, and dried in air. Corrosion resistance in the surface treated specimens was evaluated by salt immersion test using 1% NaCl solution as a time for occurring filiform corrosion. On an un-treated AZ31 alloy, the time for starting the filiform corrosion was about 1.2 ks, while on the surface treated specimen, the time was prolonged into about 1300 ks. Moreover, the surface treated specimen showed corrosion resistance in low pH solutions, such as 1% HNO{sub 3} and HCl solutions. (orig.)
The age hardening behavior of Al-4.5%Cu alloy composite reinforced with zircon sand particulates and produced by stir casting route has been investigated in different quenching media viz, water, oil, and salt brine solution (7wt%). Optical microscopy of the as cast alloy composite indicates that the matrix of the composite has the cellular structure. Copper rich CuAl2 precipitates have been found near particle matrix interface. The results of ageing demonstrate that the microhardness of age hardenable Al-Cu based alloy composites depend on the quenching medium in which they are heat treated. Salt brine quenching is faster as compared to water and oil, even if higher strength is obtained but cannot be used for complex shapes and thin sections where oil quenching is the alternative due to mi...
Separation of the bulk soluble chemical salts from the insoluble metal hydroxides and radionuclides is central to the strategy of disposing Hanford tank waste. Sludge washing and caustic leaching have been selected as the primary methods for processing the 230 million L (61,000,000 gal) of Hanford tank waste. These processes are very similar to those selected for processing waste at the West Valley Site in New York and the Savannah River Site in South Carolina. The purpose of sludge washing is to dissolve and remove the soluble salts in the waste. Leaching of the insoluble solids with caustic will be used to dissolve aluminum hydroxide and chromium hydroxide, and convert insoluble bismuth phosphate to soluble phosphate. The waste will be separated into a high-level solids fraction and a liquid fraction that can be disposed of as low-level waste after cesium removal. The washing and leaching operations involve batchwise mixing, settling, and ...
The effect of counter-ion species on the local conformation of fully-charged poly(L-glutamate) in added-salt aqueous solutions were studied by small-angle X-ray scattering(SAXS). In the case of presence of monovalent counter-ion, the scattering behaviour could be explained by taking into consideration the excluded volume effect and intermolecular-interface interaction on the scattering function of wormlike chain. On the other hand, since SAXS profile of the solution in the presence of divalent counter-ion well fitted to the scattering function of dendrimer, it suggested that the conformation of polymer chain in such solution would be more compact conformation than that of presence of monovalent ion.
This report documents the findings of the peer panel constituted by Argonne National Laboratory to review Region A of Westinghouse Electric Corporation's report entitled Waste Package Reference Conceptual Designs for a Repository in Salt. The panel determined that the reviewed report does not provide reasonable assurance that US Nuclear Regulatory Commission (NRC) requirements for waste packages will be met by the proposed design. It also found that it is premature to call the design a ''reference design,'' or even a ''reference conceptual design.'' This review report provides guidance for the preparation of a more acceptable design document.
A kind of polymer-metal complex gel electrolyte is successfully prepared and is used in dye-sensitized solar cells. Raman and X-ray photoelectron spectroscopy confirm the structure of this complex and is found that the metal ion reacts with nitrogen in the polymer. This novel electrolyte shows apparent diffusion coefficient of iodide of 8.37 x 10-7 cm2 s-1 and the energy conversion efficiency of 6.10% when the amount of ZnI2 is 0.04 M. By studying the dissociation active energy of the inorganic salt in electrolytes, we find that the metal salts can dissociate more easily after reacting with polymer and as a result can provide extra free iodide ion. The cell maintains ca. 93% of its initial efficiency after 20 d without further sealing, which shows good long-time stability.
The kinetics of the solubilization of lauric acid, palmitic acid, stearic acid, and monopalmitin have been studied in detergent solutions as a function of concentration, temperature, and fluid flow. The detergents used were sodium dodecyl sulfate (an anionic surfactant), decyltrimethylammonium bromide (a cationic surfactant), sodium taurocholate (a trihydroxy bile salt), sodium taurodeoxycholate (a dihydroxy bile salt), and triton X-100 (a nonionic surfactant). At low temperature, solubilization can be described by a five-step mechanism is which micelle desorption and diffusion are rate controlling. At temperatures above the fatty acid penetration temperature, solubilization is governed by formation of a liquid crystalline phase at the fatty acid-detergent solution interface.
Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are important to define.
Proteins aggregated into spherulite structures of amyloid fibrils have been observed in patients with certain brain diseases such as Alzheimers and Parkinsons. The conditions under which these protein spherulites form and grow are not currently known. In order to illuminate the role of environmental factors on protein spherulites, this research aims to explore the kinetics and mechanisms of spherulite formation and growth, as monitored by optical microscopy, in a range of salt concentrations, and initial protein concentrations for two model proteins: bovine b-lactoglobulin and insulin. These two proteins are significantly different in their size and fibril growth rate, but both of these proteins have been shown previously to form amyloid fibrils and spherulites under low pH conditions. The...
We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10{sup -6} S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.
We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10-6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.
Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 ..mu..m; drops of diameter size 1.5 ..mu..m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water.
Tests on the scrubbing column have led to the following results: Use of a scrubbing column with Raschig rings is only meaningful for the sedimentation of particles exceeding diameters of 0.5 #mu#m; drops of diameter size 1.5 #mu#m are formed in the column; more efficient drop precipitators in the column air flow ease the load on subsequent suspended material filters thereby contributing to a longer life of these filters even at higher sodium ion concentrations in the washing water; with distillate of an 8% rather than 0.8% salt solution a decontamination factor greater than 10 can be calculated since larger particles precipitate more readily. This only applies, however, under the condition that the washing water is renewed regularly, if necessary daily where higher aerosol concentrations are present. If not, the decontamination factor will be reduced through the salt-containing secondary aerosols from the washing water. (orig.).
This paper aims to study fundamentally the impacts of membrane properties on the reactive dye removal from dye/salt mixtures by nanofiltration membranes. To begin with, two types of nanofiltration membranes of similar pore size, namely asymmetric cellulose acetate membrane and thin-film composite polyamide membrane were fabricated, and their key physical, chemical and performance properties were characterized. After that, these resultant membranes were employed to perform dye removal experiments with aqueous solutions of reactive black 5 and NaCl under different operational parameters. The dye removal rate and steady permeate flux were determined and correlated with the measured membrane properties. It was found that there were significant differences between the dye removal performances o...
Tests on a sample of trench water from the Maxey Flats burial ground effectively demonstrated the new Reverse Osmosis Pilot Plant. The effluent from the 50% salt-rejection membrane was decontaminated well enough with the exception of tritium to be discharged to the environment. The performance of the 97% salt-rejection membrane was superior to that of the 50% membrane. A breakthrough and capacity experiment was conducted with Durasil 10 on a simulated Three Mile Island solution. The maximum decontamination factor was extrapolated to be 10/sup 6/, which would reduce the cesium level of TMI water to below the discard limit. Capacity (1/DF = 0.5) was reached at 1260 column volumes. Several adsorbents were tested in the engineering columns for decontamination of cesium-bearing solutions. Under the conditions of the experiment, these adsorbents were ineffective in removing cesium from the solution.
Normal butylamine compounds are studied as salt-free wash reagents for degraded solvent used in PUREX process in spent fuel reprocessing. The solvent wash tests were carried out with two types of butylamine compounds, n-butylamine oxalate and n-butylamine bicarbonate, by counter-current mode using a small size mixer-settler composed of two 4-stage wash steps. Di-n-butyl phosphoric acid (HDBP), the main degradation product from TBP, was removed from real degraded solvent with decontamination factor of 2.5 {approx} 7.9. The study on electrolytic decomposition of butylamine compounds was also conducted for waste treatment.
As research for the chemical properties of lanthanide molecules in the dry system, electrochemical and ultraviolet-visible optical measurements on the chloride molten salt system have been conducted at Research Reactor Institute, Kyoto University. The reduction behavior of Ln(III)-Ln(0) and Ln(II) are measured on La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Yb by the cyclic voltammetry. The molar absorption coefficients of the f-f transition are measured by the measurement of ultraviolet-visible absorption spectra on Pr, Nd, Ho and Gd. From the comparison of the optical data between wet and dry systems, the characteristics of photon absorption are discussed in the molten salt. (H. Katsuta)
Dispersal can be regarded as a process operating both between and within patches of suitable habitat. For uncontrolled dispersal processes, the risk of crossing the borders of the habitat patch and arriving in the unsuitable landscape matrix will increase with decreasing patch area, in particular when the distance between isolated habitat patches is larger than the species' average dispersal capacity. Ballooning dispersal in spiders can be considered as a passive dispersal process, in which dispersed distances depend on the prevalent wind velocity. We executed a reaction norm analysis to analyze how dispersal propensity of the salt marsh wolf spider Pardosa purbeckensis depended on population characteristics (patch size) and the environment (wind velocity). Dispersal propensity was affecte...
The effects of TANOL radical have been examined on chemical shifts and relaxation rates of /sup 109/Ag NMR in aqueous solution of silver salts. The silver ion in aqueous solution is found to coordinate with TANOL radical. A small amount of TANOL is added as a doping agent(0.020M), since /sup 109/Ag signals are obtained for (1.0M) silver ion within 30 minutes. The /sup 109/Ag chemical shifts of silver salt in aqueous solutions were found within the range of 0 to -1000 ppm relative to that of 1.0M AgNo/sub 3/.
The effect of atmospheric radioactive emissions from United Kingdom nuclear installations on acid deposition is assessed. Nitrogen oxide and ozone production resulting from and associated with discharges of airborne radioactivity, comparison with conventional emissions, and the direct effects of radioactive emissions on trees, are all discussed. (UK).
An examination is made of the structure of the North Saremboyskiy oil field and productive lower Devonian deposits of well 15. Based on detailed lithological studies, as well as investigation of filtering-capacitance properties of rocks, the complex structure of the carbonate deposits and the dominant development of complex type collectors is indicated.
Magnetron sputter deposition was used to fabricate body centered cubic (bcc) and A-15 crystal structure W thin films. Previous work demonstrated that the as-deposited crystal structure of the films was dependent on the deposition parameters and that the formation of a metastable A-15 structure was favored over the thermodynamically stable bcc phase when the films contained a few atomic percent oxygen. However, the A-15 phase was shown to irreversibly transform into the bcc phase between 500 C and 650 C and that a significant decrease in the resistivity of the metallic films was measured after the transformation. The current investigation of 150 nm thick, sputter deposited A-15 and bcc tungsten thin films on silicon wafers consisted of a series of experiments in which the stress, resistivity and crystal structure of the films was measured as a function of temperatures cycles in a Flexus 2900 thin film ...
Exploration for oil shale in Queensland between June 1986 and July 1987 continued over 12 deposits ranging in age from Permian to Tertiary. The total estimated resource of shale oil contained within these deposits is 4479 GL (28.2 billion barrels). 4 refs., 1 fig., 1 tab.
Natural radioactivity of rocks is studied on the basis of core samples and radioactivity logs of marine deposits in Azerbaijan. Investigations have established mainly thorium-potassium nature of radioactivity. Data obtained are useful for identificafion of clay among other rocks, for determination of clayiness, and in presence of a corresponding relation - for determination of porosity according to the clayiness. It is shown that the clayiness may be determined from radioactive logs.
The mobilization and distribution of previously deposited "2"3"9Pu was compared in pregnant rats (15 and 20 days of gestation) and nonpregnant controls. Pregnancy had little effect on "2"3"9Pu tissue burdens and only minimal activity appeared in the fetoplacental unit. Marked differences were observed in tracer "4"5Ca deposition patterns between the experimental groups.
The formulation of the problem of classification of lithologically heterogeneous rocks and rocks with mixed capacity space is analyzed under conditions of self-teaching. Using the example of one of the boreholes of the Pripyat trough we illustrated the possibilities of the Kompakt algorithm to classify deposits of the Frasnian stage without using standard data. Problems are listed for further study on the development of methods of application of self-teaching classification systems in the petroleum industry.
In accordance with the comprehensive plan in the eleventh five-year period the main content of prospecting and exploration on land in Axerbaidzhan by the Axneft' association will be done in the central and Western regions of the republic, where Paleogene-Mesozoic deposits will be inspected. Discussed in detail are the directions and volumes of prospecting and exploration in individual regions of Azerbaidzhan. They are determined with consideration of the degree of exploration of the earth's interior, the prospects for the deposits comprising them, and the development of the resources of oil.
Approximately 700m of deep water clastic deposits of Mt. Messenger Formation are superbly exposed along the Taranaki coast of North Island, New Zealand. Biostratigraphy indicates the interval was deposited during the time span 10.5-9.2m.y. in water depths grading upward from lower bathyal to middle-upper bathyal. This interval is considered part of a 3rd order depositional sequence deposited under conditions of fluctuating relative sea-level, concomitant with high sedimentation rates. Several 4th order depositional sequences, reflecting successive sea-level falls, are recognized within the interval. Sequence boundaries display a range of erosive morphologies from metre-wide canyons to scours several hundred metres across. All components of a generic lowstand systems tract--basin floor fan, channel-levee complex and progading complex--are present in logical and temporal order. They ...
The Buntsandstein facies outcrops along a 12 km long, 150 m thick cuesta near Ayllon (Central Spain). The outcrop study is based on vertical sedimentological sections and continuous photo paneling, and demonstrates the presence of two depositional systems: an alluvial fan system in the lower half of the outcrop, and a straight and braided river system in the upper part of the outcrop. This overall evolution is probably related to base-level fall to base-level rise cycle, in which the reservoir architecture is linked to genetic units stacking pattern: during the base-level fall, the alluvial fan is prograding over sand flat and sandy alluvial plain deposits. Coarse and pebbly proximal sandsheets are interbedded with finer reddish distal deposits. Reservoirs units are laterally continuous, but silty alluvial plain deposits constitute vertical permeability barriers, during base-level stillstand, erosive ...
The glacial deposits of the West Tensleep Basin in the Bighorn Mountains of Wyoming are mapped and a relative chromology established. The deposits are correlated with the regional model as defined in the Wind River Mountains. A statistical analysis is performed on the density and weathering characteristics of the surficial boulders to determine their validity as indicators of relative age. (ACR)
Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.
The principal types of uranium deposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a significant thorium resource. Geological features reflecting ...
This paper examines the correlation between mechanical properties and the density, phase, and hydrogen content of deposited alumina layers, and compares them to those of sapphire and amorphous alumina synthesized through ion-beam irradiation of sapphire. Alumina films were deposited using electron beam evaporation of aluminum and co-bombardment with O{sub 2}{sup +} ions (30-230 eV) from an electron cyclotron resonance (ECR) plasma. The H content and phase were controlled by varying the deposition temperature and the ion energy. Sapphire was amorphized at 84 K by irradiation with Al and O ions (in stoichiometric ratio) to a defect level of 4 dpa in order to form an amorphous layer 370 nm thick. Nanoindentation was performed to determine the elastic modulus, yield strength and hardness of all materials. Sapphire and amorphized sapphire have a higher density and exhibit superior mechanical properties in comparison to the ...
Abstract A next generation material for surface passivation of crystalline Si is Al2O3. It has been shown that both thermal and plasma-assisted (PA) atomic layer deposition (ALD) Al2O3 provide an adequate level of surface passivation for both p- and n-type Si substrates. However, conventional time-resolved ALD is limited by its low deposition rate. Therefore, an experimental high-deposition-rate prototype ALD reactor based on the spatially separated ALD principle has been developed and Al2O3 deposition rates up to 1.2-nm/s have been demonstrated. In this work, the passivation quality and uniformity of the experimental spatially separated ALD Al2O3 films are evaluated and compared to conventional temporal ALD Al2O3, by use of quasi-steady-state photo-conductance (QSSPC) and carrier density ...
Highly conductive biaxially textured RuO_2 thin films were deposited on technically important SiO_2/Si substrates by pulsed laser deposition, where yttria-stabilized zirconia (YSZ) produced by ion-beam-assisted-deposition (IBAD) was used as a template to enhance the biaxial texture of RuO_2 on SiO_2/Si. The biaxially oriented RuO_2 had a room-temperature resistivity of 37 #mu##OMEGA#-cm and residual resistivity ratio above 2. We then deposited Ba_0_._5Sr_0_._5TiO_3 thin films on RuO_2/IBAD-YSZ/SiO_2/Si. The Ba_0_._5Sr_0_._5TiO_3 had a pure (111) orientation normal to the substrate surface and a dielectric constant above 360 at 100 kHz. copyright 1998 Materials Research Society.
During last decade, considerable interest has been focused to assess the influence of human activities on ecosystems. The increasing trend in the atmospheric concentration of CO{sub 2} has been predicted to continue till the next century and the amount of nitrogen deposition in the northern hemisphere has increased markedly. Substantial interest has been focused on predicting how these changes will affect on plants. Most boreal mire ecosystems are dominated by mosses of the genus Sphagnum, the litter of which constitutes the main component in the peat deposits and is an important CO{sub 2} sink via peat formation. Since virtually nothing was known about the growth response of peat mosses to elevated concentrations of CO{sub 2} and alerting changes in species composition were detected in the sensitive ombrotrophic mire vegetation under increased N deposition in central Europe, this study was established. Laboratory ...
The microstructure, microhardness, corrosion, and wear resistance of d.c.-plated Ni electrodeposits prepared from different types of electrolysing Watts-type baths, without or with organic compounds, ceramic powder - SiC and polymer - polytetrafluoroethylene (PTFE), on Cu substrate, which was subsequently removed from the deposits, were investigated. With the change of the type of bath, the deposit grain size was found to decrease markedly, e.g. deposits with an average grain size of about 50 nm could be produced from the bath containing 45 g/dm"3 Ni"2"+ ions, 5 g/dm"3 SiC, and 20 g/dm"3 PTFE. The surface morphology on the bath side of the electrode-posited Ni or Ni-SiC-PTFE foils was characteristic of the type of bath, and its roughness correlated well with the observed grain size. Microhardness and wear resistance increased with decreasing grain size, as expected. On discussing the factors controlling ...
The Grand Canyon Quadrangle (2/sup 0/), northwestern Arizona, was evaluated to identify environments and delineate areas favorable for the occurrence of uranium deposits. This was done using criteria developed for the National Uranium Resource Evaluation. General surface reconnaissance and geochemical sampling were carried out in all geologic environments within the quadrangle. Aerial radiometric and hydrochemical and stream-sediment reconnaissance surveys were performed, although results were not available in time for field checking. The results of this investigation indicate environments favorable for: channel-controlled, peneconcordant sandstone deposits in the Petrified Forest Member of the Chinle Formation in the north-central part of the quadrangle, vein-type deposits in collapse breccias in all areas underlain by the Redwall Limestone, and unconformity-related deposits in the metasediments of the ...
An in-plane uniaxial magnetic anisotropy has been observed in thin Co films normally deposited onto obliquely sputtered Ta and Pt underlayers. Associated with this anisotropy is an augmented easy axis coercivity. The in-plane easy axis is, in most cases, perpendicular to the incident deposition plane. Microstructural results indicate that grains are well connected along the magnetic easy axis but are separated by long continuous voids along the hard axis, which is ascribed to a geometric shadowing effect due to the oblique incidence deposition of the underlayer. Hence, the magnetic anisotropy mimics the film growth anisotropy. It is therefore believed that the observed magnetic properties are due to magnetostatic shape anisotropy effects. In-plane coercivity and anisotropy field are shown to increase with underlayer deposition angle, underlayer thickness and magnetic layer thickness. The choice of ...
Iron oxide films have been deposited on Si(100) substrates by chemical vapour deposition (CVD) of iron(III) tert-butoxide ([Fe(O "tBu)_3]_2) in the temperature range 350-450 deg. C. The precursor flux and substrate temperature were varied to control the phase composition, average grain size and film thickness. The nature of substrate and deposition temperature markedly influence the morphology and iron-oxygen stoichiometry in the CVD deposits. Phase transformations in iron oxide films were achieved through precise local and periodic heating of the films by interfering laser beams. The interaction of iron oxide films with short laser pulses (Nd:YAG, 355 nm) induced partial transformation of hematite (#alpha#-Fe_2O_3) to magnetite (Fe_3O_4) or magnetite to wuestite (Fe_1_-_xO), respectively. The phase characterization and morphology of the hematite and magnetite films were investigated before and after ...
The Sunoco Felda oil trend of the South Florida basin has been a prolific oil producer. All the oil is produced from the Cretaceous Sunniland formation, a leached limestone bioherm. Although the producing section has been considered reefal in the literature, petrographic and biostratigraphic analyses of various cores in producing fields have determined that these deposits are composed of particles of fragmented rudist and other fauna deposited in a tidal shoal. Atop this debris an algae and gastropod section has been deposited, typical of a mound deposited on a tidal mud flat. This model is exemplified in the Sunoco Felda and West Sunoco fields and was used in exploring the Sunoco Felda trend. From the petrological analysis of these two fields and from knowledge of other wells in the basin, biostratigraphic and lithologic trends can be determined and extended offshore into the eastern Gulf of Mexico. ...
The objective of this project were to investigate the dynamic behavior of peat and to evaluate the influence of that behavior on the dynamic response of peat deposits. During the course of the research, the objectives were expanded to explore the effects of strong earthquake shaking on pile foundations embedded in peat deposits. An experimental investigation was undertaken using samples of a peat deposit typical of many large peat deposits in western Washington. A series of ground response analyses was performed to investigate the seismic response of peat deposits. Three vertical profiles through Mercer Slough were analyzed using both equivalent linear and nonlinear ground response analyses. The analyses showed that the soft nature of the Mercer Slough peat would produce amplification of the long-period components of an earthquake ground motion. Comparison of the equivalent linear ...
Coal washery wastes comprise tailings finer than 0.5 to 0.1 mm depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30% solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37{degree} (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour ...
In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is ...
High-resolution sequence stratigraphy taking base-level cycles as interface of reference was developed rapidly in recent years. Its greatest predominance lies in that it can be applied to multi-controled continental sedimentary basins and can effectively improve accuracy and distinguishability of sequence stratigraphy analysis. Principles of base-level cycles can also be applied to the research and practice of the exploration and exploitation of sandstone-type uranium deposits as they control the spatial distribution, porosity, the permeability and the sealing ability of sandstone and mudstone, and stacking patterns of strata configuration. Taking Dongsheng uranium deposits as an example, the application of base-level cycles to exploration and exploitation of sandstone uranium deposits was analyzed. It is suggested that favorable strata framework of sandstone and mudstone was developed very well in the fluctuation of ...
Deposition of hard coatings may influence the mechanical properties of the bulk material and its corrosion resistance. In this work we study the hardness of the coated and the back side of 100Cr6 steel plates. Electrochemical corrosion tests were performed in O{sub 2}-saturated acetate buffer of pH 5.6 at 25degC. Chromium nitride and titanium nitride coatings prepared by different physical vapour deposition processes, such as arc, thermionic arc evaporation, magnetron sputtering and ion-beam-assisted deposition (IBAD) were compared. The results show that, for sufficient corrosion protection, chromium nitride layers have to be thicker than 500 nm. An increased nitrogen partial pressure in the evaporation chamber of the IBAD process improves the corrosion resistance significantly. The hardness of the substrates was reduced in the case of thermoionic arc evaporation only, indicating a deposition ...
Sprat Sprat in the Southwestern Baltic Sea (including Sound and Belt Sea) ...episodic salt water inflows which occur during autumn to spring.The last major inflow to the Baltic Proper ...The small inflows in spring 1986 and fall 1988 have had only effects on salinity and temperature
Consideration is given to results of investigation into thorium complexing with morin (H_2Mor) in extraction systems containing different carboxylic acids as well as different salt background. The obtained data enabled to suggest the method of photometric determination of thorium in the form of Th(HMor)_2Benz_2 different-ligand complex (where Benz-anion of benzilic acid) with 0.25 #mu#g/ml detection limit.
Relative densities and relative massic heat capacities have been measured for aqueous solutions of Y(ClO_4)_3, Yb(ClO_4)_3, Dy(ClO_4)_3, and Sm(ClO_4)_3 at T=(288.15,298.15,313.15, and 328.15) K and p=0.1 MPa. These measurements were made in the concentration range 0.01624#<=#m/(mol#centre dot#kg"-"1)#<=#0.41822 using a Sodev 02D Vibrating Tube Densimeter and a Picker Microflow Calorimeter, respectively. To counter the potential effects of hydrolysis, aqueous solutions of the investigated salts were acidified with perchloric acid. After correcting for the presence of the acid, the measured properties were used to calculate apparent molar volumes and apparent molar heat capacities for solutions of the perchlorate salts in water. The calculated apparent molar properties were modeled at each investigated temperature using Pitzer ion interaction equations to produce estimates of apparent molar volumes and heat capacities at infinite dilution. ...
By dissolution of iron (2) carbonate in rhenium acid iron (2) perrhenate of the Fe(ReO/sub 4/)/sub 2/x4H/sub 2/O composition is obtained. By the method of thermal analysis the limits of tetra-, dihydrate and anhydrous iron (2) perrhenate stability are revealed. By means of X ray phase and IR spectroscopic analysis methods modification of structure in the process of synthesized salt dehydration is shown.
The threshold stress itensities for stress corrosion crack propagation in beta titanium alloy 38-6-44, Ti-3Al-8V-6Cr-4Mo-4Zr, has been determined in salt water and methanolic solutions. The alloy was immune to stress corrosion cracking in aqueous sodium c...
An evaluation was made of the effectiveness of the action of reagents used for cleaning cyan-containing waste water for conditioning of the overflow of copper concentrate thickners of the Belousovskiy enrichment before sorption extraction of gold by activated charcoal. It was established that conditioning of the overflow by iron sulfates (II), copper and zinc diminshes, and by hypochlorite increases the capacitance of the activated charcoal for gold.
Research investigating applicability of lithium salts for solid electrolyte batteries was described. The studies included determinations of lithium ion conductivities in solid electrolyte systems based on Li4SiO4, LiTi2(PO4)3, and ceramic materials. Research on all solid state lithium cells utilizing TiS2 NiPS3 electrodes was also reported.
This paper presents ionic conductivity results obtained with polymer electrolytes and also with propylene carbonate solutions. The domain of electrochemical activity of this salt has been determined using cycle volt-amperometry in propylene carbonate. Preliminary experiments on the stability of the polymer electrolyte with respect to the lithium electrode have been carried out for a possible subsequent use in lithium batteries. (J.S.) 4 refs.
Analytical expression of the dependence of freezing temperature of electrolyte (CdCl_2, CdSO_4, BeSO_4) aqueous solutions on their composition was found. Three different methods were suggested were suggested for calculation of water activity in multicomponent solution. It was established that sublinear extrapolation of freezing temperature of salt aqueous solutions was possible not up to -5 deg C, but up to -15 deg C, independently of their composition. 6 refs.; 2 figs.
Over the past several years, the Livermore Forensic Science Center has conducted analyses of nuclear-related samples in conjunction with domestic and international criminal investigations. Law enforcement officials have sought conventional and nuclear-forensic analyses of questioned specimens that have typically consisted of miscellaneous metal species or actinide salts. The investigated activities have included nuclear smuggling and the proliferation of alleged fissionable materials, nonradioactive hoaxes such as 'Red Mercury', and the interdiction of illegal laboratories engaged in methamphetamine synthesis. (author)
A new procedure for an efficient and sparing cleaning procedure of turbines was developed. The procedure uses cleaning and passivation chemicals that solve effectively and homogeneously salt and ferrous oxide coatings from turbines, avoiding attacks from corrosion, plugging and unbalances. In several high-pressure and condensation turbines the cleaning procedure has been already put into practice. (orig.)
The complexing of paramagnetic salts of molybdenum and tungsten with tri-tert-butylphenyl ester of 1,2-naphthoquinone-diazide-(2)-5-sulfochloride is studied by PMR and EPR methods. From the changes of half-widths of lines in PMR spectra and analysis of g-factor in EPR spectra, the kinetic and thermodynamic parameters of the complexing are determined, and the composition of the complexes formed is established, and the schemes of their formation are suggested.
French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.
Chemical oxidation is a treatment technology that uses powertul chemical oxidizers to destroy organic contaminants. Typical oxidizers used in chemical oxidation processes include ozone, hydrogen peroxide, chlorine, and potassium permanganate. The chemical reaction products are usually simple organic compounds, such as carboxylic acids, and/or inorganic compounds, such as carbon dioxide, water, and simple inorganic complexes (e.g., chloride salts, in the case of chemical oxidation treatment of chlorinated solvents).
The bibliography contains citations concerning Federal and state laws and management programs for the protection and use of inland wetlands. Utilization of wetlands to control highway runoff and community wastewater is discussed. Wetlands protection programs, restoration projects, resource planning, and wetlands identification methods are cited. References to coastal and salt water wetlands are not included in this bibliography. (Contains 250 citations and includes a subject term index and title list.)
This paper reports about in-situ corrosion studies on selected materials for long-term resistant high-level waste (HLW) packagings acting as a barrier in a rock salt repository. The materials (Ti 99.8-Pd, Hastelloy C4 and five iron-base materials) were investigated in heated boreholes in the Asse salt mine under simulated HLW disposal conditions prevailing in normal operation of repository and in certain accident scenarios. The experiments under normal operating conditions were performed at temperatures of 120 deg. C to 210 deg. C (vertical temperature profile in the boreholes) without and with gamma irradiation (3#centre dot#10"2 Gy/h, Co-60 source) within the framework of the German/US Brine Migration Test. In these experiments only small amounts of migrated brine inclusions (NaCl-rich) from the rock salt were present as corrosion medium. In the experiments carried out under simulated accident conditions with intrusion of ...
Results are described of the study of the analytical applicability of a highly efficient ion source developed for a mass spectrometer. Its ionizer is in the form of a partially closed cavity with a small aperture for leading out ions, heated to a high temperature. The new ion source increases the sensitivity of the apparatus in operations with transuranium elements by almost two orders of magnitude. It is possible to perform isotopic analyses with a high salt content in the sample, and to study the characteristics of nuclear fuel, even without chemical separation of the sample elements.
Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were either filled with air or with a molten mixture of sodium nitrate, potassium nitrate and an oxidizer. Low-cycle fatigue tests were carried out at 1200/sup 0/F and 650/sup 0/F by cycling the strain continuously between equal mangitude of tensile and compressive values at a rate of 4 x 10/sup -3/sec/sup -1/ until failure. The creep-fatigue tests were carried out at 1200/sup 0/F. The loading cycle differed from that of low-cycle fatigue testing only in the imposition of a hold at the peak compressive strain in each cycle. Cracks always initiated on the inner surface of the hollow specimen, and therefore, corrosive effects on crack propagation and initiation were controlled by the environment within the specimen cavity. In common with tests carried out earlier on steam-filled alloy 800 specimens, at 1200/sup 0/F in the presence of molten salt the heat of ...
The estimation of numerical values of the mean distance of closest approach of ions, a, of heavy metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.
It is shown that bending tests on microsamples can be used to study the conditions in which hydrogen brittleness develops. In such tests hydrogen brittleness develops in the VTI5 alloy within the temperature range +5 to -20"0C. The tendency of VTI5 to develop hydrogen brittleness is enhanced with bending in salt water. (author).
The paper gives results of experiments in a 0.1 MW pilot plant to determine the effects of high concentrations of chloride ions and dissolved salts on flue gas desulfurization (FGD) scrubbing chemistry, both in the natural and forced oxidation modes of operation. (Note: The tight...
Cesium and selenium intake of cultivated mushrooms (Agaricus bisporus), with these elements previously added to culture medium, has been examined from the viewpoint of health- and environmental protection. The process of measuring has been carried out by the radionuclide X-ray fluorescence technique. Treatments of the elementary substance with Se salt appears to influence the Se content of the mushrooms to a significant extent. Cs intake is of considerable importance, as this element is accumulated by mushrooms. (author)
The temperature and concentration dependence of the densities of binary CaBr_2-(Li, Na, K, Rb, Cs)Br, NaBr-(Sr, Ba)Br_2 and KBr-SrBr_2 mixtures have been measured using the method of hydrostatic weighing. With exception of the systems LiBr-CaBr_2 and NaBr-(Sr, Ba)Br_2 the calculated molar excess volumes are positiv in the investigated mixtures. (author).
A process is provided for conducting organic compound conversion over a catalyst composition comprising a supported crystalline zeolite having a high initial silica-to-alumina mole ratio, said supported zeolite being prepared by compositing said crystalline zeolite with alumina, reacting the composite with a particular hydrogen fluoride solution in a specified way, drying the hydrogen fluoride reacted composite, treating the dried composite by hydrolysis, ammonolysis and/or by contact with an ammonium salt solution, and calcining the resulting material.
Absorption of the excimer laser radiations of 193-nm argon fluorine and 308-nm xenon chloride in balanced salt solution, sodium hyaluronate, and human cadaver eyes was measured. The absorption of these materials as considerably different for the two wavelengths; we found that 308-nm light experienced much less absorption than the 193-nm light. The extinction coefficient (k) for 308 nm was k = 0.19/cm for balanced salt solution and k = 0.22/cm for sodium hyaluronate. In contrast to this, the extinction coefficient for 193 nm was k = 140/cm for balanced salt solution and k = 540/cm for sodium hyaluronate. Two 1-day-old human phakic cadaver eyes showed complete absorption with both wavelengths. Using aphakic eyes, incomplete absorption was noted at the posterior pole with 308 nm and complete absorption was noted with 193 nm. The extinction in the anterior part of aphakic eyes (the first 6 mm) was 4.2/cm for 308 nm, meaning ...
The growth of stoichiometric and non-stoichiometric silicon nitride films was studied experimentally on 100 mm silicon wafers by batch depositions from the dichlorosilane (SiH{sub 2}Cl{sub 2})-ammonia (NH{sub 3}) system in a hot-wall horizontal low pressure chemical vapor deposition (LPCVD) reactor. The growth kinetics were discussed in terms of the Langmuir adsorption isotherm. The kinetic parameters were determined by comparing the experimental data with a one-dimensional simulation model. The decomposition of NH{sub 3} at high temperatures was included in the simulation procedure. When the SiH{sub 2}Cl{sub 2}:NH{sub 3} ratios were greater than 1.5, a quantity higher than the thermodynamic critical values above which Si-rich nitride films begin to deposit, various SiN{sub x} films with x < 4/3 were obtained. The composition of the SiN{sub x} films was found to vary along the LPCVD reactor. The film stoichiometry was ...
After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and ...
Crystalline and non-crystalline iron oxide (#alpha#-Fe_2O_3) thin films were obtained by spray pyrolysis onto glass substrate at different temperatures. The results of X-ray diffraction showed that with increasing the deposition time, the film structure changed from non-crystalline to crystalline at the same substrate temperature. At different substrate temperatures and low deposition times (5 min), iron oxide appears almost in non-crystalline form. With rising the substrate temperature and deposition time, the crystallinity was improved. The effect of substrate temperature as well as deposition time on the optical features (absorption coefficient and bandgap) and optical constants of these films has been investigated. Optical constants of the films were determined from spectrophotometric measurement of reflectance and transmittance. Analysis of the results showed that, for non-crystalline iron oxide ...
A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore ...
Over one-third of Canada's coal resources occurs in the southern Canadian Rocky Mountains, with major deposits in the Front Ranges, Inner Foothills and Outer Foothills. In the Front Ranges, deposits of metallurgical and thermal, high-volatile bituminous to semi-anthracite coal occur in the Late Jurassic-Early Cretaceous Mist Mountain Formation. In the Inner Foothills of northeastern British Columbia and west-central Alberta, resources of metallurgical and thermal medium- and low-volatile bituminous coal occur in Early Cretaceous strata of the Gething and Gates Formations. In the Outer Foothills resources of thermal, high-volatile bituminous coal occur in Late Cretaceous and Paleocene strata of the Belly River Coalspur and Paskapoo Formations. The major deposits of the Front Ranges and Inner Foothills accumulated within the coastal plains of the Fernie and Moosebar-Clearwater seas. Shorelines prograded to the north ...
This poster presentation gave an overview of the subaqueous deposition of reactive mine tailings in the open trench Don Rouyn, located near Rouyn-Noranda, Quebec. The author began by providing a brief background of subaqueous mine tailing storage, and discussed the interest of the Don Rouyn trench. The site was described according to geomorphological and geological aspects. The hydrology conditions existing at the site were mentioned, and the results of the hydrology analysis performed were indicated. Close monitoring of the situation was maintained, and the chemical and physical stability of the tailings were evaluated. The conditions that prevailed both before and after the flooding of the site were explained. Water quality is being monitored, and the results obtained at this site might be used at other locations. 40 figs.
Nanocrystalline chromium oxynitride films were deposited by reactive RF magnetron sputtering of metallic chromium target in argon and helium atmospheres. The paper deals with consequence of increase in oxygen partial pressure on structural, hydrophobic and optical properties of chromium oxynitride films. The film stoichiometry changes from CrN and Cr2O3 to only Cr2O3 with increase in oxygen partial pressure as evident from X-Ray Diffraction analysis in both cases. The average crystallite size decreases with increase in oxygen partial pressure for both gas atmospheres. The thickness calculated from transmission data and surface profilometer are in good harmony with each other. The deposited films are hydrophobic by nature and the contact angle of the films varies as a function of surface ro...
Indium sulfide thin films consisting of porous network of nanoplatelets, have been deposited using chemical bath deposition (CBD) method onto the tin-doped indium oxide (ITO) coated glass substrate. Aqueous solutions of indium sulfate and thioacetamide have been used as indium and sulfur precursors. As a complexing agent, acetic acid was used. The chemically deposited indium sulfide thin films were examined for their structural, surface morphological and optical characterizations. The X-ray diffraction analysis revealed the formation of the cubic b-In2S3 onto the substrate. From scanning electron micrograph, it is observed that the surface of substrate is covered by nanoporous platelets type morphology. The optical studies showed a direct band gap of 2.84eV for indium sulfide platelets. Ph...
Pinealectomy completely prevented gonadal regression as well as reduction in body weight and white adipose tissue content of the gonadal and retroperitoneal fat deposits in male meadow voles transferred from long to short day lengths. Pineal influences on pelage characteristics depended on which parameter was assessed. For instance, the increase in guard hair length observed in short-day control voles was blocked by pinealectomy; however, a similar increase in underhair length was unaffected by removal of the pineal gland. Photoperiod-dependent changes in fat deposition, testicular activity, and guard hair length presumably rely on altered pineal secretory activity to transduce the effects of day length on the neuroendocrine axis; however, mechanisms independent of pineal activity may be capable of mediating photoperiodic control of underhair growth. PMID:2979644
The performance of Ag-promoted Pd/Al2O3 catalysts, which were prepared by the selective deposition of Ag onto Pd using a surface redox (SR) method, during acetylene hydrogenation was compared with that of catalysts prepared by impregnation. The Pd surface was more effectively modified with Ag added by SR, even when small amounts of Ag were added. The catalyst prepared by SR showed a higher ethylene selectivity than the one prepared by impregnation, because SR allowed both the preferential deposition of Ag on the low-coordination sites of Pd and a greater electronic modification of Pd by Ag.
Morphology of castellated Be tiles from the belt limiter exposed to the JET plasma for 56,000 s was examined on both sides of castellated grooves, on plasma-facing and side surfaces of the tiles. The essential results are (i) deuterium retention in the castellated grooves and in other locations is associated with co-deposition of carbon; (ii) the decay length of deposition in the castellation is around 1.5 mm; (iii) no deuterium is detected in bulk Be; (iv) bridging of gaps by molten beryllium occurred but gaps were not filled with Be; (v) on side surfaces of the tiles the formation of BeO layer was detected at a distance of 20 mm and more from the plasma-facing surface. The consequences for a long-term operation of a reactor-class device with several different plasma-facing materials are addressed.
Yttria stabilized zirconia (YSZ) with 8 mol% Y was deposited by reactive magnetron sputtering onto oxidized (100) silicon substrates. It was possible to switch film texture from (111) to (200) by applying a strong RF substrate bias. Transmission electron microscopy showed that the film deposited under bias is porous and exhibits nanoscaled grains, whereas the film deposited without bias is dense and columnar. The ionic conductivity as a function of temperature revealed an activation energy of 1.04 eV. The mechanical stress could be tuned to low values by thermal post-annealing. Using the dense (111) film as electrolyte layer, and the porous (200) film as an interlayer to a porous Pt anode, an open circuit voltage of 0.85 V was obtained in a micro machined fuel cell structure.
Abstract Smoke is a mixture of toxic gases and suspended particulate matter of solids and liquids that evolves from a fire of flammable materials. This article presents real-time consequence modeling to track the concentration of individual species in smoke as well as its soot deposition. In the modeling process presented, the burning rate or vapor mass is fed into a combustion model in which the combustion of products has been identified and quantified along with the temperature of the fire. The output of the combustion model is the smoke that will be dispersed into the ambient. The fire geometry, which depends on the type of fire (e.g., pool or flare), is identified. A dispersion model with the capability of determining particulate deposition is then used for tracking the smoke plume. Th...
The in-depth distribution of phases in c-BN films deposited by Ion Beam Assisted Deposition (IBAD) at two different ion energy values (300 and 600 eV) was investigated using the quantitative IR transmission measurements and the HREM technique. Whatever the value of the studied ion energies, the characteristic layered morphology of c-BN film is observed including the interfacial sp"2 zone between the substrate and the c-BN volume. In the case of 600 eV ion energy, this interfacial zone is less well-defined in comparison with 300 eV ion energy and the corresponding thickness is more important. Furthermore, the h-BN phase is more diluted within the c-BN film volume showing that the purest phase concentration of c-BN is found for the lowest ion energy, i.e., 300 eV.
Nano structured carbon nitride thin films were deposited at different RF powers in the range of 50 W to 225 W and constant gas ratio of (argon: nitrogen) Ar:N_2 by RF magnetron sputtering. The atomic percentage of Nitrogen: Carbon (N/C) content and impedance of the films increased from 14.36% to 22.31% and 9 x 10"-"1 #OMEGA# to 7 x 10"5 #OMEGA# respectively with increase in RF power. The hardness of the deposited films increased from 3.12 GPa to 13.12 GPa. The increase in sp"3 hybridized C-N sites and decrease of grain size with increase in RF power is responsible for such variation of observed mechanical and electrical properties.
The Model of Acidification of Groundwaters in Catchments (MAGIC) was used to simulate the impact of acidifying deposition and future recovery at the Gaardsjoen Covered Catchment Experiment, at a number of hypothetical stations defined by statistical variation of the Gaardsjoen data and at 20 forest monitoring sites in Southern Sweden. For the future predictions a decrease of sulphur deposition of more than 70% was assumed. This assumption is based on a full implementation of the agreements made under the second sulphur protocol from 1994. The modelled impact of reduced deposition on the soils and on the runoff waters was discussed. To complement the discussion on long-term trends in future run-off chemistry, data from Gaardsjoen has been used to asses the risk for short-term acid runoff episodes 26 refs, 23 figs, 7 tabs
Abstract The Jebel Ressas Pb-Zn deposits in North-Eastern Tunisia occur mainly as open-space fillings (lodes, tectonic breccia cements) in bioclastic limestones of the Upper Jurassic Ressas Formation and along the contact of this formation with Triassic rocks. The galena-sphalerite association and their alteration products (cerussite, hemimorphite, hydrozincite) are set within a calcite gangue. The Triassic rocks exhibit enrichments in trace metals, namely Pb, Co and Cd enrichment in clays and Pb, Zn, Cd, Co and Cr enrichment in carbonates, suggesting that the Triassic rocks have interacted with the ore-bearing fluids associated with the Jebel Ressas Pb-Zn deposits. The 18O content of calcite associated with the Pb-Zn mineralization suggests that it is likely to have precipitated from a fl...
Microcrystalline silicon carbide ({mu}c-SiC) was prepared at low substrate temperatures using Hot Wire chemical vapor deposition (HWCVD). High crystalline volume fractions were achieved at high hydrogen dilution and high deposition pressure. Without intentional doping, such material shows high dark conductivity and high optical absorption below the band gap. The material prepared at low deposition pressure or low hydrogen dilution, on the other hand, shows much lower conductivity and sub-gap absorption, but high spin densities up to 5 x 10{sup 19} cm{sup -3}. This high absorption can be attributed to free carriers, different to {mu}c-Si:H where a correlation between the sub-gap absorption and the spin density is observed.
Tokamaks with sufficiently strong supplementary heating develop non-Maxwellian electron velocity distributions. Because the absorption of electron cyclotron power is proportional to #nabla#_Vf, even small deviations from a Maxwellian distribution can significantly affect power deposition. Following an approach used to study microinstabilities in a plasma with an arbitrary, numerically specified, electron distribution, we have developed a computational module to study electron cyclotron power deposition in plasmas that have distributions motivated by those in actual tokamaks. Also, we compare the deposition results obtained using an energy balance approach with those obtained using a Taylor expansion of the dielectric tensor. We illustrate the limitations of the latter approach.
Palladium deposition on Pt(110) electrodes was studied. Differently from Pt(111) and Pt(100), first and further layers cannot be distinguished in this case only through the voltammetric behavior of hydrogen and anion adsorption. The potential of zero total charge (pztc) was determined as a function of the amount of deposited Pd using CO charge displacement experiments and voltammetric curves. The variation of the voltammetric charge due to hydrogen and anion adsorption has been followed during Pd deposition. The voltammetric charge between 0.06 and 0.4V first decreases to a minimum, then increases and finally becomes stable, suggesting that the surface is finally covered with a Pd multilayer. The pztc and CO oxidation charge show similar behavior. CO oxidation, NO reduction and Cu UPD were...
In this work the DC and AC characteristics for metal-LB film-metal structures deposited by a standard Langmuir-Blodgett film deposition technique are investigated. The conduction mechanism has been studied for a thin film structure in which a calix[4]arene substituted with carboxylic acid groups has been deposited alternately with a calix[4]arene molecule substituted with amine groups. This LB film structure shows a typical insulating behaviour for low voltage values and the Schottky effect becomes dominant when the voltage increases. The conductivity at low voltage values was found to be 1.34x10^-^1^3Scm^-^1. The height of the potential barrier was determined to be 1.65eV for this alternate layer LB film system.
TiB{sub 2} appears to be a promising material for the wear protection in various tribological systems, e.g. the diecasting of Al. This study focuses on the development of titanium boride coatings deposited by PACVD, a deposition method which is most suitable for the coating of substrates with complex shapes. All layers analysed are very smooth and exhibit a quasi-amorphous fracture surface. XRD and TEM analysis indicate a nanocrystalline structure with grain sizes in the order of 2 nm. The diffraction patterns can well be correlated to titanium diboride. WDS reveals an over stoichiometric B/Ti ratio. The layer hardness reaches the value of 33 GPa and the critical load in scratch tests rises to 35 N. Neither 100Cr6 nor Al as a counterpart in pin-on-disk tests leads to wear of the coating. (orig.)
The Jaduguda U (?Cu?Fe) deposit in the Singhbhum shear zone has been the most productive uranium deposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ? chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A ? high Co (up to 30800?ppm), no/low Ni; type-B ? moderate Co (up to 16500?ppm) and moderate to high ...
A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.
Villarrica (Chile) is one of the most active volcanoes in South America having erupted about 60 times in the last 460years. Although its historical eruptive activity has been mainly effusive and weakly explosive, it had strong explosive behaviour in postglacial times. Chaimilla (<3.1ka) is one of the best exposed and widely dispersed pyroclastic deposits, related to both fall and flow activity. The deposit is dispersed over an area of 250km^2 and consists of 8 units (A-H) which were grouped into four sequences. Stratigraphic data suggest that the eruption had a relatively short duration and evolved from i) an Opening phase, dispersing ash, lapilli clasts, accretionary lapilli, blocks and bombs, to ii) a Pulsatory phase, originating a series of magmatic explosions, to iii) a Collapsing phas...
A one-nanometer scale transmission electron microscope electron probe X-ray microanalysis characterization of as-deposited and annealed aluminum--11.5 at.% zirconium multilayer samples in cross-section synthesized by magnetron sputtering is reported on here. Composition line profiles were acquired across Zr layers in as-deposited material and samples isochronally annealed in a differential scanning calorimeter to temperatures of 290 C and 485 C. A spatial resolution of approximately 1.5 to 2.0 nm was achieved in these experiments and will be improved by deconvolution of the instrumental electron probe function from the data. The as-deposited structure consisted of crystalline Al and Zr layers with thin amorphous layers at the Al/Zr interfaces. The amorphous interface layers increased in thickness upon annealing to 290 C. Additionally, at 290 C a metastable cubic alloy forms at the Zr deposited on Al ...
Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the ...
Background and objectives: The pathogenesis of acquired nephrogenic systemic fibrosis recently described for patients with renal insufficiency and a history of exposition to gadolinium-based magnetic...Full Text Available
In this work, amorphous hydrocarbon (a-C:H) film deposition on metallic mirrors was studied during working shots in tokamak T-10 and at exposure in Ar/CHD3/D2 dc magnetron discharge in a special laboratory high vacuum setup. Analysis of film composition (including hydrogen content) was carried out using nuclear physical methods. Thickness and optical parameters (refractive and extinction coefficients) of the films were estimated by ellipsometry. Laboratory films can be characterized as soft a-C:H films in comparison with hard tokamak films (? = 1.2 and 1.8 g/cm3, respectively). For the first one, a linear dependence of deposition rate on mirror temperature was observed in a wide temperature range. The addition of methane into initial Ar/D2 magnetron gas mixture leads to an increase of deposition rate. The data obtained should be taken into account to prevent hydrocarbon film formation on the surface of first mirrors in ...
Storage proteins are deposited into protein storage vacuoles (PSVs) during plant seed development and maturation and stably accumulate to high levels; subsequently, during germination the storage...Full Text Available
Samples dredged from the sediment mounds have a unique chemistry and mineralogy which reveals details of the hydrothermal processes that produce these deposits. The mounds form primarily by deposition of Fe, Mn and Si from hydrothermal fluids which circulate through the basalt crust and the overlying sediments. The Mn, Fe and Si are strongly fractionated in the process; the Fe and Si precipitate within the mounds under slightly reducing conditions as nontronite, while the Mn is deposited as Mn oxyhydroxides at the seawater-sediment interface. The nontronite is exceptionally well crystallized, and contains less than 200 ppm Al. The Mn minerals, todorokite and birnessite, also have exceptional crystallinity and the distribution of trace elements Cu, Ni, Zn, Co, Ca and Ba in these phases agrees with predictions made on the basis of models of their crystal structure. The environment of deposition which ...
The variation in the superconducting properties of various binary alloys of transition metal-germanium systems was surveyed by studying sputter deposited samples prepared under various conditions. The primary interest has been to study the formation of the stoichiometric A-15 compounds T_3Ge.
The initiation and characteristics of mossy zinc electrodeposits have been investigated. Batteries with zinc electrodes are candidates for electric vehicle applications; however, this electrode is prone to form non-compact deposits that contribute to capacity loss and battery failure. Moss is deposited when the current density is far from the limiting current. This morphology first appears only after the bulk deposit is approximately 1 {mu}m thick. In this investigation, the effects of flow rate (Re=0--4000), current density (0--50 mA/cm{sup 2}), concentration of the electroactive species (0.25 and 0.5 M), and the concentration of supporting electrolyte (3, 6, and 12 M) on the initiation of moss were examined. The rotating concentric cylinder electrode was employed for most of the experiments; and a flow channel was used to study the development of morphology. After the experiment, the deposit was ...
If bone strength was the only requirement of skeleton, it could be achieved with bulk, but bone must also be light. During growth, bone modelling and remodelling optimize strength, by depositing bone...Full Text Available
A variety of special regulations exist in Costa Rica for registration and transport of hazardous substances; these set the requirements for entry into the country and the security of transport units. However, the regulations mentioned no specific rules for storing hazardous substances. Tax deposits have been the initial place where are stored the substances that enter the country.The creation of basic rules that would be regulating the storage of hazardous substances has taken place through the analysis of regulations and national and international laws governing hazardous substances. The regulatory domain that currently exists will be established with a field research in fiscal deposits in the metropolitan area. The storage and security measures that have been used by the personnel handling the substances will be identified to be putting the reality with that the hazardous substances have been handled in tax deposits. A ...
Critical power at boiling transition is an important factor in a boiling water reactor (BWR) fuel bundle design. Boiling transition under high quality accounts for dryout as the result of the complete disappearance of film flow on a fuel rod. This liquid film vanishing process can be calculated by the liquid film model, which takes into account the evaporation due to heat from the rod surface, liquid film entrainment by steam flow, and liquid droplet deposition. It is known that spacers affect liquid film entrainment and liquid droplet deposition, so the detailed study of spacer effects on hydrodynamic characteristics is necessary for critical power prediction based on the film flow model. Many studies have been conducted to examine spacer effects on liquid film flow. However, most of them are restricted to simple test sections such as a rectangular conduit. There are a few reports on fuel bundle geometry; however the bundle studied was only a ...
A procedure was developed to monitor boundaries within which secondary mining operations can be applied. Principal techniques include instrument and operative-remote observations of earth shifts and aerial photography of displacements on the surface of the trough.
Operating PWR units in the USA have experienced very severe corrosion of the tube support plate at the crevice between the tube and the support. This results in distortion of the plate and crushing of the tube (denting). The first task of this project required that currently available computational methods to estimate the pH attained by concentrating boiler water under various fault conditions such as condenser leakage of river waters and faulty operation of condensate polishing plant. Particular attention has been paid to systems in which sulfate predominates. In the second task, the mechanisms are discussed by which solutions become concentrated in porous deposits on a boiling heat transfer surface. It is concluded that more experimental data are needed to test the validity of existing models. High solution concentrations in the deposit may occur at a heat flux close to the critical value for drying out the base of the ...
Focused ion beam (FIB) milling is a powerful and versatile tool for the maskless fabrication of structures and devices at micro- and nanometer scales. The approach is based on the milling and deposition capabilities of a focused ion beam, where the latter is achieved by ion-beam-assisted decomposition of a metalorganic gas precursor of the specific material that has to be deposited. The combination of FIB and scanning electron microscopy in the same unit (so-called dual-beam unit) further expands the capabilities of the approach by the possibility of performing electron-beam-assisted deposition and inspection. Permalloy nanowires with electrical contacts patterned by FIB-Pt deposition were prepared in the dual-beam unit. Various types of notches to pin magnetic domain walls were additionally fabricated by means of FIB. The fabrication parameters for a structural modification of the Permalloy structures ...
Iron oxide thin films have been obtained by spray pyrolysis using 100% methanolic and ethanolic solutions of iron tri-chloride. The films were deposited onto ITO-coated glass substrates. The preparative conditions have been optimized to obtain compact, pin-hole-free and smooth thin films which are adherent to the substrate. The structural, morphological and compositional characterizations have been carried out by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The films deposited using ethanolic solution results into pure hematite; #alpha#-Fe_2O_3 thin films, however, films deposited using methanolic solution consists of hematite and maghemite-c phases of iron oxide. The films are nanocrystalline with particle size of 30-40 nm. The optical absorbance of the film was of the order of 10"5 cm"-"1. The optical band gap of films was found to be 2.26 and 2.20 eV for the films ...
This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine...Full Text Available
Platelet-derived growth factor (PDGF) is a potent moderator of soft tissue repair through induction of the inflammatory phase of repair and subsequent enhanced collagen deposition. We examined the effect...Full Text Available
A method to control charge transfer reaction in DNA using hybrid nanometer-sized TiO{sub 2} nanoparticles was developed. In this system extended charge separation reflects the sequence of DNA and was measured using metallic silver deposition or by photocurrent response. Light-induced extended charge separation in these systems was found to be dependent on the DNA-bridge length and sequence. The yield of photocatalytic deposition of silver was studied in systems having GG accepting sites imbedded in AT runs at varying distances from the TiO{sub 2} nanoparticle surface. Weak distance dependence of charge separation indicative of a hole hopping through mediating adenine (A) sites was found. The quantum yield of silver deposition in the system having a GG accepting site placed 8.5 {angstrom} from the nanoparticle surface was found to be {Phi} = 0.70 (70%) and {Phi} = 0.56 (56%) for (A){sub n} and (AT){sub n/2} bridge, ...
The electromagnetic field due to an air explosion is here studied: neutron and the gamma-rays, generated by neutronic reactions, deposit energy which ionizes atmosphere; recoil electrons are also created by gamma collisions. This data set allows to solve the Maxwell equations which manage the electromagnetic field. The TRIPOLI-2 code studies the coupled neutron-gamma transport in 3D- geometries by the Monte Carlo method. The code has been modified to calculate the photon energy deposited in matter and the recoil electron current created by Compton effect. The method is tested wiht a simple case; then neutron and gamma transport is studied in air kerma, deposited photon energy, electron current are calculated as functions of space and time and the contributions of the different neutronic reactions are separately evaluated. The calculations presented here are only part of studies about this subject. Developments will relate ...
... recognized in the genus in which one inhabits forest litter and the other inhabits streams (Verdade, 2005). The forest litter species deposit their eggs in humid habitats, with ... ...
A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...
A radio frequency sputtering apparatus with a pair of targets has been developed for depositing a film of uniform thickness onto a complex-geometric specimen such as the retainer of a ball bearing. The deposition characteristics of the apparatus were compared with those of the conventional sputtering apparatus. Lubrication properties of MoS/sub 2/ films made by these devices were also compared under a variety of conditions. Finally, friction and wear of MoS/sub 2/ films applied to angular-contact type ball bearings of 20 mm bore were studied in air, nitrogen and vacuo. The two-target sputtering has an advantage mentioned above. However, the films deposited by the method exhibited a rather short wear life because of the temperature rise of the substrate during ion bombardment and during the sputtering process. This temperature dependence was observed in films on those substrates that had been heated with a built-in heater ...
Investigation of Interaction of Laser Radiation with Radioactive Deposits on the metal Surface and Creation of Experimental Stand for Development of Laser Technology for Remote Treatment of Materials Contaminated with Radioactive Substances at the Atomic Power Plants
BackgroundApolipoprotein E (ApoE), a cholesterol carrier associated with atherosclerosis, is a major risk factor for Alzheimer's disease (AD). The low-density lipoprotein receptor...Full Text Available
Intravascular coagulation, thrombosis, and fibrin deposition often produce tissue damage in allogeneic inflammatory reactions such as allograft rejection. The mechanisms which initiate blood clotting...Full Text Available
Focused Ion Beams are an important approach for nanostructure fabrication in the semiconductor industry and material sciences. Applications in sputtering and ion induced deposition of materials are investigated. The IMSA FIB system equipped with the high resolution Orsay Physics CANION M31plus ion column with current densities up to 10 A/cm"2 including a gas injection system is applied. In this work the ion beam induced chemical vapour deposition of tungsten, wherefore tungsten hexacarbonyl as precursor gas is used for a first investigation. Conductive tungsten-nanowires with smallest cross-section upon a substrate of Si and SiO_2 are produced. The ion beam parameters of this focused ion beam system are optimized for the metal deposition. A short insight in the theory of layer nucleation and growth induced by the ion beam during the metal deposition is given. The layer quality is determined by Auger ...
A definition is given for the basic national economic task of developing the recovery of hydrocarbons from bitumen-containing rock and oil shales, and a description is given of the status of the mineral-raw material base. General concepts are given on bitumens and oil shale. Their elemental and group compositions are cited in detail, and a determination is made of the position they occupy in the total system of fossil fuels. An examination is made of data on the distribution and state of bitumen and oil shale resources, and a description is given of their principal deposits. An evaluation is made of gained experience and the potential of existing methods of working bituminous rock and oil shale deposits that include the use of available and utilized method of land-based, underground, and instrastratal extraction of petroleum from those deposits. A presentation is made of the technical-economic aspects of producing ...
Linking biological samples found at a crime scene with the actual crime event represents the most important aspect of forensic investigation, together with the identification of the sample donor. While...Full Text Available
Several avian species show a bright carotenoid-based coloration during spring and following a period of duller coloration during the previous winter, despite carotenoids presumably being fully deposited...Full Text Available
Geometric (HOMA) and magnetic (NICS) indices of aromaticity were estimated for aromatic rings of amino acids and nucleobases. Cartesian coordinates were taken directly either from PDB files deposited...Full Text Available
A review of the literature on chronic inhalation studies in which rats were exposed to mineral fibres at known fibre number concentrations was undertaken to examine the specific roles of fibre length...Full Text Available
A pure culture of an Agrobacterium sp. (deposited as ATCC 55002) that mineralizes the ferric chelate of EDTA (ferric-EDTA) was isolated by selective enrichment from a treatment facility...Full Text Available
The diagnostic accuracy of computed tomography (CT) in several patterns of thoracic and abdominal fatty masses, has been examined. In selected cases our findings overlap the features of the recent literature. The possibility of surgical therapy in peculiar cases of adipose deposits, commonly esteemed benign, is considered.
Molecular chaperones protect cells from the deleterious effects of protein misfolding and aggregation. Neurotoxicity of amyloid-beta (Aβ) aggregates and their deposition in senile plaques are...Full Text Available
In the present work, a rapid deposition anodic stripping voltammetry (ASV) for determination of uranium is presented. For this purpose, the uranyl hexacyanoferrate (K2UO2[Fe(CN)6]) is deposited electrochemically on a thin palladium-aluminum electrode (Pd-Al) from a UO22+ solution in the presence of K3Fe(CN)6. Then, the well stable (K2UO2[Fe(CN)6]) on the electrode was stripped by anodic differential pulse voltammetry for measuring the UO22+ ion concentration. The effect of operational parameters, including: concentration of K3Fe(CN)6, solution pH, deposition potential, and deposition time were studied. In optimum conditions, the calibration graph was linear in the concentration range 105-7 x 10-4 mol L-1 with a detection limit of 6.2 x 10-6 mol L-1. The influence of some concomitant ions in K2UO2[Fe(CN)6] formation was investigated. The proposed method was used for the rapid determination of uranium in ...
Methods of acidizing a subterranean well formation, acidizing compositions, and sequestering additives for preventing the precipitation of metal compounds in the formation are described. Use of the methods and chemicals described should lead to improved formation permeability as compared to use of previous methods and chemicals. 12 claims.
Chromium containing amorphous hydrogenated carbon films (a-C : H/Cr) have been prepared by simultaneous rf plasma activated chemical vapour deposition of methane and magnetron sputtering of a chromium target. During deposition the substrates were heated (up to 300C) and DC biased (-200 and -600 V) in order to obtain films with high chemical stability. Constant temperature tests were performed at 250C in air with coatings deposited on silicon substrates. The degradation of the coatings was monitored by Raman spectroscopy and reflectance and transmission measurements. The main degradation mechanisms are discussed and the relevant parameters which improve the durability of the coatings are presented. Furthermore, the durability of solar selective, multilayered coatings which were deposited on copper sheets was investigated. Based on accelerated aging tests at different temperature loads in air (at 220C, ...
Fourier Transform Infrared (FTIR) spectroscopy has been utilized during high rate E-beam evaporation/deposition of YBa2Cu3O7 (YBCO). The results demonstrate the great utility of FTIR as an in situ monitor of YBCO deposition and processing. We detect different (amorphous/fine polycrystalline) insulating pre-existing phases to the high Tc superconducting phase which appear to have distinct reflectivity fingerprints dominated by thin film interference effects, as a function of temperature and oxygen pressure. These fingerprints reveal some of the kinetic and thermodynamic pathways during the growth of YBCO.
Methods of X-ray diffraction and transmission electron microscopy were used to study the microstructure of dispersion-strengthened Cu-Al2O3 nanocomposites obtained by the method of simultaneous deposition of Cu and Al2O3 from the vapor phase. The effect of the size of particles of the oxide (Al2O3) and of their content on the electrical resistance of the composite has been considered. The results obtained make it possible to suppose that the main structural factor that determines the electrical resistance of the composite are nanodispersed particles of Al2O3 with a size of less than 20 nm.
When nanometer scale holes (diameters of 50 to a few hundred nm) are imaged in a scanning electron microscope (SEM) at pressures in the 10{sup -5} to 10{sup -6} torr range, hydrocarbon deposits built up and result in the closing of holes within minutes of imaging. Additionally, electron beam deposition of material from a gas source allows the closing of holes with films of platinum or TEOS oxide. In an instrument equipped both with a focused ion beam (FIB), and an SEM, holes can be formed and then covered with a thin film to form nanopores with controlled openings, ranging down to only a few nanometers.
Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition-rate measurements using molecular beam scattering and a very low-pressure cold-wall reactor. The RSCs have nonlinear Arrhenius temperature dependencies and decrease with increasing flux at low (710 /sup 0/C) temperatures. Several simple models are proposed to explain these observations. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction and low-pressure chemical vapor deposition-rate measurements.
Magnetic materials such as yttrium iron garnet (YIG) are of great importance for its magneto-optic properties and for their potential applications in the domain of optical telecommunications. The deposition of thin films of YIG, on quartz or GGG (gadolinium gallium garnet) substrate, was performed using radio frequency non reactive magnetron sputtering, followed by high temperature annealing which is needed to enhance the crystallinity of the layers. Rutherford backscattering spectrometry RBS was used to determine the thickness and stoichiometry of the performed layers in order to investigate correlations between growth conditions and the quality of the final material. RBS measurements showed the influence of the deposition time and the temperature substrate on the film growth and its stoichiometry. (author)
Microwave Electron Cyclotron Resonance (ECR) Plasma assisted Chemical Vapor Deposition (CVD) technology has been used to prepare Si_3N_4 films, which were analyzed by using infrared (IR) transmission spectroscopy and XPS. The analysis results show that with the increase of the deposition temperature, the H content decrease, and the densification of the film increases. When the temperature is up to 360 degree C, the stoichiometrical rate of Si:N is close to 0.75. The protective property of Si_3N_4 films is also examined
Processing techniques utilizing low temperature depositions and pulsed lasers allow the fabrication of polysilicon thin film transistors (TFT`s) on plastic substrates. By limiting the silicon, SiO2, and aluminum deposition temperatures to 100(degrees)C, and by using pulsed laser crystallization and doping of the silicon, we have demonstrated functioning polysilicon TFT`s fabricated on polyester substrates with channel mobilities of up to 7.5 cm2/V-sec and Ion/Ioff current ratios of up to 1x10(to the 6th power).
A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.
A study of the thin gold film growth, during the deposition on glass substrate under UHV conditions at low temperatures, is presented. The complementary methods, the atomic force microscopy and grazing incidence x-ray reflectometry, are used for the research. It is shown that due to variation of the time of deposition from 2 to 50 min different kinds of thin Au films nanostructures are obtained: from discontinuous films consisting of isolated islands, via formation of the chains of islands, up to continuous films. (author)
Many organic compounds can be adsorbed onto the interface of a metal and solution to form a thin film that inhibits the corrosion process according to a blocking and/or negative catalytic effect. Using the Langmuir-Blodgett (LB) technique, stearic acid (SA) monolayers were deposited onto the surface of an iron (Fe) electrode to study the inhibition effect and the mechanism of SA in a neutral medium. Molecular orientation and the number of deposited monolayers of SA were shown to have marked effects on inhibition of Fe corrosion. The inhibition mechanism depended mainly on blocking.
The refractory nature and high ductility of body centered cubic (bcc) phase tantalum makes it a suitable material for corrosion- and wear-resistant coatings on surfaces that are subjected to high stresses and harsh chemical and erosive environments. Sputter deposition can produce thick tantalum films but is prone to forming the brittle tetragonal beta phase of this material. Efforts aimed at forming thick bcc phase tantalum coatings in both flat plate and cylindrical geometries by high-rate triode sputtering methods are discussed. In addition to substrate temperature, the bcc-to-beta phase ratio in sputtered tantalum coatings is shown to be sensitive to other substrate surface effects.
The most important kaolin deposits from Campo Alegre region (S C) were formed by the conjunction of at least one hydrothermal phase followed by many others weathering, supergenic, phases. Possibly deposits formed by only one of these processes exist, but these deposits shall be small and smaller than those mined today. Besides kaolinization, illitization/muscovitization and silicification, hydrothermalism also generated pyritized and propilitized zones, with quartz + chlorite. Together, hipogenic alterations related to kaolin deposits are very similar to alterations of high sulfidation epigenetic volcanogenic gold deposits. Most part of the biggest kaolin mines from the southern part of Campo Alegre Basin are distributed along a 13 Km long and 0,5 Km width bent zone that is parallel to structural alignments that point out the eastern Basin border. This zone was originated by ...
The concentrates of scattered organic matter???kerogen-like polymer, which is insoluble in acids and organic solvents???were isolated from rock samples taken at different depths from various stratigraphic units at the productive deposits of the Orenburg oil-gas condensate field using chemical methods. The chemical composition of the kerogen-like polymer and the concentrations of trace elements in it were studied. The regularities of evolutionary changes in the composition of the organic matter and the concentrations of trace elements in it in the order of the kerogen-like polymer and the following its consecutive derivatives were established: asphaltenes, ethanol-benzene tars, benzene tars, oils, and paraffins
As a part of the Finnish radioactive waste disposal research three holes (the size of deposition holes) were bored in the research tunnel at Olkiluoto in Finland. A novel full-face boring technique was used based on rotary crushing of rock and removal of crushed rock by vacuum flushing through the drill string an the purpose of the work was to demonstrate the feasibility of the technique. During the boring test procedures were carried out in order to determine the effect of charges in operating parameters on the performance of the boring machine and the quality of the hole. (refs.).
Different technological procedures used for the chemical mining of uranium differ for one thing with a level of the deposit exploitation and for another with the expenditures. It is necessary to find out the highest acceptable value of the costs per unit of production - limit unit costs. This criterion serves both for selection of the minable parts of deposit, and for determination of the exploitation level of the deposit parts. The paper describes a calculation of the costs and their decomposition into the fixed and variable costs. An evaluation of the different variants of the deposit exploitation is based on the variable costs, expressed in the dependence on the parameters of technological procedure. These parameters are either primary, e.g. density of the wells or dosage of reagents, or secondary, e.g. the uranium production. A relation between primary and secondary variables is defined by the ...
Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure ...
The optical, electromagnetic and mechanical properties of thin films (TFs) are directly correlated to their morphology at the nanoscale. This, in concert with the fact that new deposition techniques are enabling the growth of thin films with very complex morphologies, there is an increasing interest in model-based simulation (MBS) for the design of engineering structures (including nanostructures), and increasing computer speeds are beginning to make MBS an effective design tool capable of bridging the nanoscale with the continuum scale, has made it increasingly important to understand how the nanostructure of a thin film impacts its properties at all length scales. The authors have developed the capability to determine the mechanical properties of thin films with amorphous nanostructure by combining molecular dynamics, i.e., position of particles (e.g., atoms or molecules) and their interatomic potential(s), with continuum mechanics principles. This work concerns ...
Microstructure and electrical properties of iron oxide Fe_2O_3 thin films prepared by spray pyrolysis method have been experimentally characterized. The effect of substrate temperature as well as deposition time on the structural features (crystallite size and microstrain) and electric resistivity of these films has been investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) characterized the structure study. The results of X-ray diffraction showed that with increasing substrate temperature bias the film structure changed from amorphous to crystalline at the same deposition time. At a substrate temperature of 350 deg. C and low deposition time, #alpha#-Fe_2O_3 appears almost in amorphous form. With rising the substrate temperature and deposition time, the crystallinity was improved. At T_s_u_b>350 deg. C, a well-crystallized rhombohedral phase of #alpha#-Fe_2O_3 was obtained. ...
In order to fabricate high temperature superconducting tapes for power applications, the authors have analyzed different buffer layer architectures grown on textured Ni substrates suitable for YBCO deposition. Due to its optimal lattice matching the studied structures present as top layer a CeO{sub 2} film. The deposition of CeO{sub 2} on Ni substrates was performed by pulsed laser ablation and by e-beam evaporation at different temperatures. The films obtained by the two deposition techniques have not optimal structural properties, having a polycrystalline component. The misorientation of CeO{sub 2} is probably due to the formation of NiO at the interface between the film and the substrate during the deposition process even if no oxygen is introduced. In order to prevent Ni oxidation an intermediate 2000 {angstrom} Pd thick film was deposited by e-beam. Furthermore, the lattice ...
The possibilities to electrodeposit thick coatings composed of nanoparticles of Sb and Sb{sub 2}O{sub 3} for use as high-capacity anode materials in Li-ion batteries have been investigated. It is demonstrated that the stability of the coatings depends on their Sb{sub 2}O{sub 3} concentrations as well as microstructure. The electrodeposition reactions in electrolytes with different pH and buffer capacities were studied using chronopotentiometry and electrochemical quartz crystal microbalance measurements. The obtained deposits, which were characterised with XRD and SEM, were also tested as anode materials in Li-ion batteries. The influence of the pH and buffer capacity of the deposition solution on the composition and particle size of the deposits were studied and it is concluded that depositions from a poorly buffered solution of antimony-tartrate give rise to good anode materials due to the inclusion ...
The Sunniland Limestone (Lower Cretaceous), consisting of carbonate rock and anhydrite, bears the only oil and gas production in southern Florida. Raccoon Point field, Collier County, Florida, is one of 13 fields discovered along the Sunniland producing trend, producing from paleotopographic highs associated with shelfal patch reefs and high-energy bioclastic deposits. Deposition of the Sunniland Limestone, as determined from detailed stratigraphic and microfacies analysis (using core, thin sections, and well logs), occurred in three transgressive-regressive packages or sequences: the lower, middle, and upper Sunniland. Each sequence is further divided into successive shallowing-upward intervals or parasequences. The dolomite reservoirs at Raccoon Point field occur at the top of the middle Sunniland and within the upper Sunniland. They are interpreted as high-energy deposits formed from bioclastic debris and as a network ...
Development of electronic devices with better performance and smaller size requires the passive components to be embedded within a printed wire board (PWB). The 'film-on-foil' approach is the most viable method for embedding these components within a PWB. We have deposited high-permittivity ferroelectric lead lanthanum zirconate titanate (Pb{sub 0.92}La{sub 0.08}Zr{sub 0.52}Ti{sub 0.48}O{sub x}, PLZT 8/52/48) films on base metal foils by chemical solution deposition. These prefabricated capacitor sheets can be embedded into PWBs for power electronic applications. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was applied by chemical solution deposition on nickel foil before the deposition of PLZT. With a {approx} 0.7-{micro}m-thick ferroelectric PLZT film grown on LNO-buffered ...
Molten salt oxidation (MSO) is a good alternative to incineration for the treatment of a variety of organic wastes such as explosives, low-level mixed waste streams, PCB contaminated oils, spent resins and carbon. Since mid-1990s, the U.S. Army Defense Ammunition Center (DAC) and the Department of Energy (DOE) have jointly invested in MSO development at the Lawrence Livermore National Laboratory (LLNL). LLNL first demonstrated the MSO process for the effective destruction of explosives, explosives-contaminated materials, and other wastes on a 1.5-kg/hr bench-scale unit, and then in an integrated MSO facility capable of treating 8 kg/hr of low-level radioactive mixed wastes. Several MSO systems have been built with sizes up to 10 ft in height and 16 inches in diameter. LLNL in 2001 completed a MSO plant for DAC for the destruction of explosives-contaminated sludge and explosives-contaminated carbon. We will present in this paper our latest demonstration data and our ...
This study presents three-dimensional simulation results of multispecies and multi-reaction electrorefining for spent nuclear waste treatment. Fluid-dynamic behavior of electrorefining is analyzed by commercial computational fluid-dynamics code. The results of local fluid dynamics are coupled with one-dimensional electrochemical reaction analysis code in order to predict local current density distribution. The new approach shows current distribution patterns over the cathode surface in LiCl-KCl molten-salt electrolyte. The current density distribution patterns are analyzed for various electrode rotational speeds and diverse applied currents and the results show a good agreement with general principle of mass transfer observations. Spatially periodic and vertically striped pattern of current density is predicted at the cathode side due to mass transfer depression at separation points. These slow mass transfer regions are vulnerable to be contaminated by transuranic ...
In this research, new thin freestanding films of poly(methyl methacrylate) (PMMA)/50% epoxidised natural rubber (ENR 50) were doped with lithium triflate, LiCF3SO3 salt was prepared by a solvent casting method. The incorporation of ENR 50 is found to increase the conductivity of PMMA/LiCF3SO3 by two orders of magnitude at room temperature. The highest conductivity achieved was 5.09x10-5Scm-1 at room temperature when 60% of LiCF3SO3 salt was introduced into the PMMA blend containing 10% ENR 50. The formation of excessive hydrogen bonds and interchain crosslinking limit the performance of the blend at higher concentrations of ENR 50. The ionic conduction mechanisms in PMMA/ENR 50/LiCF3SO3 electrolytes obey the Arrhenius rule in which the ion transport in these materials is thermally assisted...
A series of copolymers based on the cellulose acetate/propionate-g.co-acrylic acid system has been prepared under radiation-induced control. These copolymers have been assessed for their water-retention capacity both in an unmodified state and after ''decrystallization'' or ''neutralization'' treatments. The grafting of acrylic acid onto the cellulose acetate/propionate had little effect on the water retention power of the cellulose acetate/propionate. However, improvements to the water retentivity was obtained after ''decrystallization'' procedures had been carried out on the copolymers using selected alkali metal salts with methanol as the continuous medium. The water-retentivity of the copolymers increased with increase in the extent of grafting, though the effect is less pronounced at high graft levels. Neutralization of the functional groups of the ...
The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the visible arm. The RSS/NIR is a low to medium resolution spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The visible and NIR arms can be used simultaneously to extend spectral coverage from approximately 3200 A to 1.6 um. Both arms utilize high efficiency volume phase holographic gratings via articulating gratings and cameras. The NIR camera is designed around a 2048x2048 HAWAII-2RG detector housed in a cryogenic dewar. The Epps optical design of the camera consists of 6 spherical elements, providing sub-pixel rms image sizes of 7.5 +/- 1.0 um over all wavelengths and field angles. The exact long wavelength cutoff is yet to be determined in a detailed thermal analysis and will depend on the semi-warm instrument cooling scheme. Initial estimates ...
Polypeptides, copolymers of #alpha#-amino acids and #alpha#-hydroxy acids, could prove to be a valuable new class of synthetic biodegradable polymers. In this paper. steps in synthesis of poly (dl-lactide-co-3, 6-dimethylmorpholine-2,5-dione) from dl-lactide and dl-3,6-dimethylmorpholine-2,5-dione was explained. dl-Lactide was synthesized from lactic acid. In the reaction of 2-bromopropionyl chloride and dl-alanine, N-(2-bromopropionyl)-dl-alanine was prepared and this material was converted to its salt and finally this salt was converted to 3,6-dimethylmorpholine-2,5-dione in a sublime r. These two monomers, that is d l-lactide and dl-3,6-dimethylmorpholine-2,5-dione was polymerized by ring-opening polymerization. F T-IR, "1H NMR, "1"3C NMR Spectra were used for structure elucidation of all intermediate compounds and final product.
Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.
Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been proposed.
Radioactive rare earth chlorides in waste LiCl-KCl molten salts have to be separated as a stable form to minimize waste volume and to achieve stable solidification. In this work, thermal behavior of rare earth chlorides (CeCl3, GdCl3, NdCl3, PrCl3) was investigated in an oxygen condition to recover rare earth oxides from a LiCl-KCl-RECl3 system. The rare earth chlorides in the LiCl-KCl molten salts were smoothly converted to an oxychloride form at a higher temperature than 650degreeC, except for CeCl3. CeCl3 was totally converted to an oxide from at a higher temperature than 450degreeC. The rare earth oxychlorides (GdOCl, NdOCl, PrOCl) were effectively converted to oxide forms at a higher temperature than 1100degreeC. It was confirmed that rare earth oxides can be recovered from a LiCl-KCl...
The aim of this work is the comparative study of the properties of the natural graphite/liquid organic electrolyte interface by impedance spectroscopy with respect to different lithium salts (LiX with X = ClO{sub 4}{sup -}, BF{sub 4}{sup -}, CF{sub 3}SO{sub 3}{sup -}, N(CF{sub 3}SO{sub 2}){sub 2}{sup -}, PF{sub 6}{sup -}). The evolution of the interface properties during the first electrochemical reduction suggests different mechanisms of formation of passivation films. A more stable, thin and homogenous film seems to develop when the LiN(CF{sub 3}SO{sub 2}){sub 2} or LiPF{sub 6} lithium salts are used. The chemical diffusion coefficient of lithium in graphite has been determined by impedance spectroscopy. (J.S.) 16 refs.
Using a series of polycations synthesized by atom transfer radical polymerization (ATRP), we investigate the effects of the polymer charge density and hydrophobicity on salt-induced interdiffusion of polymer layers within polyelectrolyte multilayer (PEM) films. Polycations with two distinct hydrophobicities and various quaternization degrees (QPDMA and QPDEA) were derived from parent polymers of matched molecular weights poly(2-(dimethylamino)ethyl methacrylate) (PDMA) and poly(2-(diethylamino)ethyl methacrylate) (PDEA) by quaternization with either methyl or ethyl sulfate. Multilayers of these polycations with polystyrene sulfonate (PSS) were assembled in low-salt conditions, and annealed in NaCl solutions to induce layer intermixing. As revealed by neutron reflectometry (NR), polycations with lower charge density resulted in a faster decay of film structure with distance from the substrate. Interestingly, when comparing polymer mobility in ...
In the San Joaquin River Basin, California, a realtime water quality forecasting model was developed to help improve the management of saline agricultural and wetland drainage to meet water quality objectives. Predicted salt loads from the water quality forecasting model, SJRIODAY, were consistently within +- 11 percent of actual, within +- 14 percent for seven-day forecasts, and with in +- 26 percent for 14-day forecasts for the 16-month trial period. When the 48 days dominated by rainfall/runoff events were eliminated from the data set, the error bar decreased to +- 9 percent for the model and +- 11 percent and +- 17 percent for the seven-day and 14-day forecasts, respectively. Constraints on the use of the model for salinity management on the San Joaquin River include the number of entities that control or influence water quality and the lack of a centralized authority to direct their activities. The lack of real-time monitoring sensors for other primary ...
Color formation in aqueous solutions of the ditetrazolium salt blue tetrazolium (BT{sup 2+}) in the absence or presence of oxygen is a complex radiation chemical reaction. The final stable product is the poorly soluble diformazan violet to blue pigment having a broad spectral absorption band ({lambda}{sub max}=552 nm). The reaction of BT{sup 2+} with the hydrated electron proceeds by rapid reduction of BT{sup 2+} followed by protonation at the nitrogen closest to the unsubstituted phenyl group, via the two intermediate tetrazolinyl radicals shared by the ditetrazole ring nitrogens. The effect of solution pH, N{sub 2}O saturation, and the presence of the reducing agent dextrose are examined. The system serves as a radiochromic sensor and a dosimeter of ionizing radiations. Solutions of 5 mmol l{sup -1} BT{sup 2+} at pH 7.3 serve as dosimeters over an absorbed-dose range of approximately 0.2-6 kGy (dearated, with a range of 1-8 mmol l{sup -1} dextrose) and of about ...
A pyrochemical partitioning process has been conceptually designed so that the transmutation of spent LWR fuels in PEACER can produce mainly low-level waste (Class C waste) for near-surface burial. Chloride salt technology developed for IFR has been employed as the baseline. Electrorefining, reductive extraction and salt recycling steps are used to construct overall flowsheet in order to support PEACER operation. The decontamination factor for transuranic elements was estimated based on both thermodynamic models and reported experimental data. It is expected that overall decontamination factor can be as high as 10{sup 5} for transuranic elements. Final wastes from pyrochemical processing for PEACER are noble metals, alkaline earth metal, and lanthanides. The final wastes are stabilized by mixing with zeolite and glass-frits such that concentration limit for class C waste can be met. The volume of Class C waste is estimated to be small enough to ...
A pyrochemical partitioning process has been conceptually designed so that the transmutation of spent LWR fuels in PEACER can produce mainly low-level waste (Class C waste) for near-surface burial. Chloride salt technology developed for IFR has been employed as the baseline. Electrorefining, reductive extraction and salt recycling steps are used to construct overall flowsheet in order to support PEACER operation. The decontamination factor for transuranic elements was estimated based on both thermodynamic models and reported experimental data. It is expected that overall decontamination factor can be as high as 10"5 for transuranic elements. Final wastes from pyrochemical processing for PEACER are noble metals, alkaline earth metal, and lanthanides. The final wastes are stabilized by mixing with zeolite and glass-frits such that concentration limit for class C waste can be met. The volume of Class C waste is estimated to be small enough to make ...
The layer-by-layer (LBL) self-assembly has been extensively used as a simple and effective method for the preparation of polyelectrolyte multilayer films. In this work, we utilized this unique method to prepare polyimide precursor/layered double hydroxide (LDH) ultrathin films. Well-crystallized Co-Al-CO_3 LDH and subsequent anion exchanged Co-Al-NO_3 LDH were prepared and characterized by scanning electron microscopy and X-ray diffraction (XRD). By vigorous shaking of the as-prepared Co-Al-NO_3 LDH, positively charged and exfoliated LDH nanosheets were obtained. Atomic force microscopy and XRD investigations indicated the delamination of LDH nanosheets. The precursor of polyimide, poly(amic acid) tertiary amine salt (PAS) was prepared by the polycondensation of dianhydride and diamine, and subsequent amine salt formation. By using the LBL method, heterogeneous ultrathin films of PAS and LDH were prepared. The formation of the ordered ...
A new series of lithium ionic liquids were prepared by introducing of two electron-withdrawing trifluoroacetyl groups in borate salts containing two methoxy-oligo(ethylene oxide) groups in the structures. Successive substitution reactions of oligo-ethylene glycol monomethyl ether and trifluroacetic acid from LiBH_4 yielded the lithium salts, which were clear and colorless liquids at room temperature. The fundamental physicochemical properties, such as density, thermal property, viscosity, ionic conductivity, self-diffusion coefficients, and electrochemical stability, were measured. The lithium ionic liquids had self-dissociation ability and conducted ions even in the absence of organic solvents. New polymer electrolytes, named 'ion gels', were prepared by radical cross-linking reactions of a poly(ethylene oxide-co-propylene oxide)tri-acrylate macromonomer in the presence the lithium ionic liquid. An increase in the glass transition temperatures ...
Weight loss measurements were performed in 20% and 28% hydrochloric acid at 90/sup 0/C on carbon steel, 22Cr5Ni duplex stainless steel, and two superaustenitic steels - 27Cr31Ni3Mo and 19Cr25Ni4Mo -, in presence of organic substances used singly or mixed. The organic substances examined were quaternary ammonium salts (1-4-pyridyl)-pyridinium chloride hydrochloride, dodecylpyridiniumchloride, benzyldimethylstearylammonium chloride, and dodecyltrimethylammonium bromide), alkynols (1-octyn-3-ol, propargyl alcohol) and trans-cinnamaldehyde. The synergistic effect of potassium iodide on the inhibitive efficiency of the organic substances was studied. The variations of corrosion rate during the test time (normally six hours) were recorded by means of polarization resistance measurements. Polarization curves were also recorded. The results showed that the corrosion rates of the four steels examined can be reduced to less than 1 mg/cm/sup -2/ . h/sup -1/ using ternary ...
One salt and two Cu(II) complexes (H2hsm)(ox), 1, [Cu(hsm)(ox)], 2, and [Cu(hsm)(ox)H2O], 3, have been synthesized and X-ray characterized (hsm is histamine and ox2? is the oxalate dianion). Starting from the prochiral tetracoordinated complex 2, pentacoordinated complex 3 crystallizes as a racemic mixture of the enantiomeric ? and ? isomers, in space group P21/c. In all cases, the side chain of the hsm group is gauche, allowing the formation of strong hydrogen bonds in the salt 1, and to chelate the metal center in complexes 2 and 3. The combination hsm/ox seems to favor the formation of 2D supramolecular structures (planes or wavy planes), through efficient networks of N?H???O hydrogen bonds. Cell parameters: 1, P21/c, a?=?6.260 (2) ?, b?=?11.500 (4) ?, c?=?12.525 (4) ?, ??=?104.047 (17)...
In order to improve the long term reliability of lead-salt diode lasers, ohmic contacts of multilayer, thin-film structures consisting of In plus Au, Pt, Ni, and Pd have been studied. Diode lasers of PbSnTe fabricated with a variety of contacts were tested during room-temperature storage and during accelerated aging tests. The results show that contact reliablility can be improved when multiple overlapping films are used. After 4500 h of baking at 60 /sup 0/C, lasers with In-Au-Pd-Au contacts on both sides showed the least resistance increase (10%). For lasers with In-Au-Pt-Au contacts, 1 h of baking at 60 /sup 0/C is equivalent to 2 d storage at room temperature. Extrapolating these results, a 70% increase in contact resistance is expected for this type of laser after 9000 d of storage at room temperture. Our data also suggests that a smaller increase in contact resistance can be expected for lasers fabricated with In-Au-Ni-Au and In-Au-Pd-Au contacts.
Recent modifications to the EQ3/6 geochemical modeling software package provide for the use of Pitzer's equations to calculate the activity coefficients of aqueous species and the activity of water. These changes extend the range of solute concentrations over which the codes can be used to dependably calculate equilibria in geochemical systems, and permit the inclusion of ion pairs, complexes, and undissociated acids and bases as explicit component species in the Pitzer model. Comparisons of calculations made by the EQ3NR and EQ6 compuer codes with experimental data confirm that the modifications not only allow the codes to accurately evaluate activity coefficients in concentrated solutions, but also permit prediction of solubility limits of evaporite minerals in brines at 25/sup 0/C and elevated temperatures. Calculations for a few salts can be made at temperatures up to approx. 300/sup 0/C, but the temperature range for most electrolytes is constrained ...
The electroreduction process of Zr(IV) was studied at molybdenum electrode in LiCl-KCl-K2ZrF6 molten salt. The transient electrochemical techniques, such as cyclic voltammetry and chronopotenimetry were used. The experimental results showed that the electrochemical reduction of Zr(II)/Zr and Zr(IV)/Zr(II) were both diffusion-controlled process. In the 773-973K range, the diffusion coefficients of Zr(ii) and Zr(IV) were determined: DZr(II)=0.15567exp{-69.65x10^3RT(K)}cm^2/s, DZr(IV)=1.09x10^-^4exp{-44.39x10^3RT(K)}cm^2/s. The activation energy values for the diffusion process were 69.65kJ/mol and 44.39kJ/mol, respectively.
As part of a larger elastic numerical modeling project, we have been investigating how energy reflected from steeply dipping interfaces is recorded using typical multicomponent acquisition geometries. Specifically, we have been interpreting how rcflection events from the flanks of salt dome structures are distributed on 3C and 4C phones for vertical seismic profiles (VSPs) and ocean bottom seismic (OBS) or land surface surveys. The ultimate goal of this investigation is to improve the structural imaging of steeply dipping interfaces and eventually to evaluate the usc of the recorded elastic wavefield for fluid description near these interfaces. In the current work, we focus on a common assumption used when processing converted wave reflection seismic data that most PP energy is recorded on the vertical geophone and/or the hydrophone and that most PS energy is recorded on the horizontal geophones. This is a useful assumption when it is valid, because it eliminates ...
The partitioning of transuranium elements (TRUs) from high-level liquid waste (HLLW) through the use of pyrometallurgical technology has been underway since 1986, for the purpose of the improving the safety and public acceptance of the disposal of high-level vitrified waste. Prior to the pyrometallurgical partitioning process, the alkali metals can be separated at the denitration process for oxide conversion of HLLW, chlorination in a chloride salt bath can be used to effectively convert oxides to chlorides, and evaporated chlorides can be captured with high efficiency in another adopted chloride salt bath. The higher separation factors between actinides and rare earths are obtained in a LiCl-KCl/Bi system than in a LiCl-KCl/Cd system. Based on the results, we propose a practical process flow for partitioning TRUs from HLLW by pyrometallurgical technology. This process was demonstrated successfully using simulated purex waste. Each element of ...
To reduce the volume of radioactive wastes after evaporation, activity carriers can be separated from the inactive salt load. Boric acid separation from PWR concentrates was considered a preliminary stage for nuclide precipitation. In connection with the precipitation process, the reaction conditions for boric acid separation were determined by bench-scale experiments. After evaluating the known purification processes, crystallization was suggested as a practicable method. After inactive bench-scale experiments, mixed crystal formation with iron hexacyanoferrate for Cs removal was chosen. The disturbing effect of the complexing agents was neutralized by a pre-dose of iron-III-salts. By specifying the precipitation conditions, for Cs-134 an activity separation from 3,0 E + 06 Bg/l to 1,9 E + 02 Bg/l, and for Cs-137 from 5,9 E + 06 Bg/l to 1,2 E + 02 Bg/l was achieved. Accordingly, the decontamination factor for Cs-134 was 16000, and for Cs-137 ...
According to an American Petroleum Institute production waste survey reported on by P.G. Wakim in 1987 and 1988, the exploration and production segment of the US oil and gas industry generated more than 360 million barrels (bbl) of drilling wastes, more than 20 billion bbl of produced water, and nearly 12 million bbl of associated wastes in 1985. Current exploration and production activities are believed to be generating comparable quantities of these oil field wastes. Wakim estimates that 28% of drilling wastes, less than 2% of produced water, and 52% of associated wastes are disposed of in off-site commercial facilities. In recent years, interest in disposing of oil field wastes in solution-mined salt caverns has been growing. This report provides information on the availability of commercial disposal companies in oil-and gas-producing states, the treatment and disposal methods they employ, and the amounts they charge. It also compares cavern disposal costs with ...
The sodium- and potassium-dependent adenosine triphosphatase (Na+,K(+)-ATPase) maintains the transmembrane Na+ gradient to which is coupled all active cellular transport systems. The R and S alleles of the gene encoding the Na+,K(+)-ATPase alpha 1 subunit isoform were identified in Dahl salt-resistant (DR) and Dahl salt-sensitive (DS) rats, respectively. Characterization of the S allele-specific Na+,K(+)-ATPase alpha 1 complementary DNA identified a leucine substitution of glutamine at position 276. This mutation alters the hydropathy profile of a region in proximity to T3(Na), the trypsin-sensitive site that is only detected in the presence of Na+. This mutation causes a decrease in the rubidium-86 influx of S allele-specific sodium pumps, thus marking a domain in the Na+,K(+)-ATPase alpha subunit important for K+ transport, and supporting the hypothesis of a putative role of these pumps in hypertension.
Basic properties and battery performances of the novel high temperature stable lithium salt (Li{sub 2}B{sub 12}F{sub 12}, Dilithium Dodecafluorododecaborate; Li{sub 2}DFB) were studied using a Mn-based cathode and anode composed of a hard carbon and graphite mixture. The effect of co-solvents (mainly linear carbonate in electrolyte formulation of PC/EC/co-solvent (5/30/65 vol% mixture)) on conductivity, viscosity, charge-discharge capacities, rate performance, temperature performance, cycle life and storage life at 60 C was investigated. Conductivity of Li{sub 2}DFB electrolyte increased with reducing its viscosity by changing co-solvent and increasing the volume of the higher dielectric solvent. Li{sub 2}DFB electrolytes showed comparable discharge capacity and columbic efficiency against LiPF{sub 6} electrolyte. Li{sub 2}DFB electrolytes improved the storage life and cycle life of a Mn-based cell at 60 C. (author)
A divergence correction is conventionally applied to zero-offset data in an effort to preserved amplitude information. The conventional divergence correction compensates for the geometrical spreading of a point source in a horizontally layered medium where velocity varies with depth only. The dip-dependent divergence correction extends the conventional correction for improved amplitude processing of dipping beds. The dip-dependent divergence correction is computed by dynamic ray tracing, and applied to stacked data using a dip decomposition technique. This correction decreases amplitudes relative to the conventional correction for steep dips and late times. In a data example from the Gulf of Mexico, the conventional correction over- amplified the reflection off a salt dome flank by a factor of 1.6. High amplitudes near salt flanks are also associated with the presence of hydrocarbons. Applying the dip-dependent divergence correction ensures ...
A divergence correction is conventionally applied to zero-offset data in an effort to preserved amplitude information. The conventional divergence correction compensates for the geometrical spreading of a point source in a horizontally layered medium where velocity varies with depth only. The dip-dependent divergence correction extends the conventional correction for improved amplitude processing of dipping beds. The dip-dependent divergence correction is computed by dynamic ray tracing, and applied to stacked data using a dip decomposition technique. This correction decreases amplitudes relative to the conventional correction for steep dips and late times. In a data example from the Gulf of Mexico, the conventional correction over- amplified the reflection off a salt dome flank by a factor of 1.6. High amplitudes near salt flanks are also associated with the presence of hydrocarbons. Applying the dip-dependent divergence correction ensures ...
The authors described a method for determination of tissue renin activity with heterologous substrate. The preparation of the substrate was performed at several stages: salting with amonium sulfate; dialisis of the precipitate till complete separation of amonium sulfate molecules; distruction of angiotensinases by interchangeble souring and alcalization of the medium; lyophylization of the pure substrate. The obtained renin-substrate was preserved in ampules and its usage had a series of advantages--duration, economic, a possibility for standartization of the determination, etc., which were described in details in the article. The described in details also the quantitative determination of the renin activity in the tissues (renal and cerebral) with the help of the obtained substrate as the moments, modiied by the authors, were indicated. PMID:436712
The river Saale cascade consists of seven reservoirs with a total capacity of approx. 415 Mio. m[sup 3]. The entire reservoir system covers a catchment area of 1665 km[sup 2]. The water management tasks extend to the following main fields: flood protection upkeep of minimum water stock, salt load control and power generation. The energy supply capacity of the cascade is mainly used by pumped storage plants. The last of these plants, Hohenwarte II, was put into service in 1963. (orig.)
Titanate nanotubes were hydrothermally synthesized and their adsorption performances for lead(II) ion removal were studied. The results showed that titanate nanotubes ruptured in the adsorption process resulting in two distinct adsorption stages, thus achieving a maximum adsorption capacity of 3.752mmolg^-^1 of lead(II). Furthermore, it was found that the regeneration of titanate nanotubes loaded with the lead(II) ions can be readily achieved using the saturated EDTA disodium salt aqueous solution, thereby avoiding the trouble of disposal of adsorbent. The adsorption mechanism was also discussed in detail.
Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.
The initiation and inhibition of pitting corrosion on zirconium and hafnium in aqueous solutions have been investigated by potentiodynamic, potentiostatic and galvanostatic measurements at 25/sup 0/C. Effects of Cl/sup -/, Br/sup -/and I/sup -/ have been examined over a range of salt concentrations and pH. All three halide ions cause pitting attack on the two metals, but this may be inhibited by other anions. The results show that hafnium is more easily protected against pitting than is zirconium. The data are treated by the Butler-Volmer equation to yield more information about the mechanisms of the pitting corrosion.
In this paper, an environmentally friendly metal corrosion inhibitor, phytic acid, was assembled into the walls of silica nanoparticles via layer-by-layer self-assembly technique (LbL) with poly(allylamine hydrochloride). Such functionalized nanoparticles were uniformly distributed into sol-gel films for metal anticorrosion. The films showed very pronounced and lasting protective efficiency in concentrated salt aqueous solutions as indicated by electrochemical impedance spectroscopy (EIS) measurement. These results may provide a new route for the preparation of environment-friendly anticorrosion coatings.
In aqueous solutions, dissolved ions interact strongly with the surrounding water, thereby modifying the solution properties in an ion-specific manner. These ion-hydration interactions can be accounted for theoretically on a mean-field level by including phenomenological terms in the free energy that correspond to the most dominant ion-specific interactions. Minimizing this free energy leads to modified Poisson-Boltzmann equations with appropriate boundary conditions. Here, we review how this strategy has been used to predict some of the ways ion-specific effects can modify the forces acting within and between charged interfaces immersed in salt solutions.
This bibliography contains citations concerning Federal and state laws and management programs for the protection and use of inland wetlands. Utilization of wetlands to control highway runoff and community waste water is discussed. Wetlands protection programs, restoration projects, resource planning, and wetlands identification methods are cited. References to coastal and salt-water wetlands are excluded from this bibliography. (This updated bibliography contains 219 citations, 37 of which are new entries to the previous edition.)
The production and uses are described for extracellular microbial polysaccharides (generically called emulsans) and for a new class of extracellular microbial protein-associated lipopolysaccharides (collectively called alpha-emulsans) produced by Acinetobacter Sp. ATCC 31012, its mutants or recombinants. Also included are the deproteinized lipopolysaccharides (collectively called apoemulsans) obtained from such emulsans, as well as to the divalent metal, ammonium, and quaternary ammonium salts of such emulsans and apoemulsans. The materials can be used (1) in cleaning oil-contaminated vessels used to transport or store crude oil or petroleum fractions in such a manner that the residual oil may be recovered for fuel value or for refining and (2) in enhanced oil recovery.
The goals of this paper are to describe the fabrication and complete evaluation of a dihydropyridine <- -> pyridinium salt type redox system for the delivery of radioiodinated agents to the brain. Tissue distribution studies of "1"2"5I-labeled 4-iodoaniline and the redox agents were performed in rats. ["1"2"5I]Iodoaniline initially showed moderate brain uptake with subsequent release of the radioactivity from the brain. ["1"2"5I]Iodoaniline, however, when coupled to a dihydropyridine carrier showed significantly higher uptake and retention in the brain. (author).
Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more ...