The concentrations of iron, chromium, zinc, and aluminum were measured by atomic absorption spectroscopy in the lipid-soluble fractions of tar from the process stream of an experimental coal gasifier as part of large study on the health risks of coal gasification. Lipid solubility was inferred from octanol/water-partitioning and benzene-solubility tests. The properties of the lipid-soluble metals were compared to reference compounds by Sephadex LH-20 chromatography. The ability of the lipid-soluble metals to remain lipid soluble after treatment with acid and base was also tested. Lipid-soluble iron, chromium, zinc, and aluminum were present at 360, 12, 3, and 1 ppM, respectively, in the gasifier coal tar. The presence of these metals in lipid-soluble form may have important ...
This process for the preparation of nonaqueous dispersions of water-soluble polymerisates concerns compounds obtained by polymerization of water-soluble unsaturated ethylenic monomers in an emulsion of water in oil. The product is then dewatered to a maximum residual water content of 5% by means of microwaves. The process is azeotropic. The polymer has a molecular weight between 100,000 and 50,000,000, preferably between one and 10 million. Before treating with microwaves, the mixture is concentrated by conventional means until it has a polymer concentration between 20 and 65%, preferably between 40 and 60%. The microwaves have a wavelength between 0.1 and 30 cm. These polymer dispersions can be used in drilling fluids and as additives in tertiary oil recovery. 4 claims.
This paper elucidates the effect of humectant performance on the wettability of the skin. Humectants are divided into the organic compounds, such as polyols, the organometallic compounds, such as sodium lactate and pyrolidone sodium carboxylate, and the watersoluble high molecular compounds, such as polyethylene glycol and hyaluronic acid. Firstly, hygroscopic performances and characteristics of various hcmectants are illustrated. Then, the humectant performance of the skin and relation between amino acid in the horny layer and moisture content are described. The humectant performance possessed in the intercellular lipid of horny layer is also described. Furthermore, are explained the wettability of the skin by cosmetics and the role of humectant as an emulsifying assistant. A mechanism of the dry skin, improvement effect of the skin by humectants, and combining effect of the ...
Soluble epoxide hydrolase (sEH) plays an important role in the metabolism of endogenous chemical mediators involved in the regulation of blood pressure and inflammation. 1,3-Disubstituted ureas with a polar group located on the fifth atom from the carbonyl group of urea function are active inhibitors of sEH both in vitro and in vivo. However, their limited solubility in water and relatively high melting point lead to difficulties in formulating the compounds and poor in vivo efficacy. To improve these physical properties, the effect of structural modification of the urea pharmacophore on the inhibition potencies, watersolubilities, octanol/water partition coefficients (log P), and melting points of a series of compounds was evaluated. For murine sEH, no loss of inhibition potency was observed when the urea pharmacophore ...
A series of cleavable water-soluble silicone surfactants were prepared by the reaction of a hydroxyl-terminated polyester and an organopolysiloxane. Cleavable surfactants can decompose into water-insoluble moiety of silanol and two water-soluble products under acidic conditions, whereas these compounds are stable under neutral or alkaline conditions. The structure change of theses cleavage products are confirmed by IR and UV spectra analysis. The fundamental surface activity including surface tension, foaming, contact angle and viscosity are studied. The photocatalytic degradation of modified silicone surfactants with UV light over titanium oxide was investigated. Experimental results have confirmed that products are slowly degraded by direct photolysis. However, the cleavable silicone sur...
In this paper we describe how cleavable surfactants decompose into water-insoluble silanols and two water-soluble products when subjected to vacuum plasma treatment. We used Raman spectroscopic analysis to confirm these structural changes, and we performed contact angle measurements and employed scanning electron microscopy to observe the surface morphologies of these compounds. Our contact angle measurements confirm that the products had degraded on nylon fabrics during argon gas plasma treatment. All of the PEG-silicone polyesters displayed excellent water-repellency; PEG6000-silicone exhibited the largest contact angle (130?) and, hence, the greatest water-repellency. Our results indicate that the silanols that form upon plasma treatment may be useful in coatings applications. We also f...
Discusses scaling of closed systems for cooling coal gas from black coal coking. Scaling rate and factors that influence scaling are analyzed. Physical and chemical properties of scale buildup on the inner walls of pipe cooling systems are evaluated. Water pH value and its effects on scaling and solubility of chemical compounds that form scale are discussed. Use of ammonium sulfate for scale control is analyzed. Consumption rate of ammonium sulfate depends on ambient temperature, water pH value and chloride content in return water. Formulae for calculating optimum content of ammonium sulfates for scale control are derived. 3 refs.
Alkylaldehyde-bisulfite adducts with octyl, decyl, and dodecyl groups (CnS: n=8,10,12) were synthesized and the surface-active properties of the water-solublecompounds were compared. Exchange of the counter anions of C10S and C12S from sodium to tetramethylammonium solubilized them in water. The latter ammonium salt (C12S-QA) had surface activities as good as a classical surfactant, sodium dodecylsulfate, and dissociated promptly in weakly basic solution at room temperature to be a non-surfactant. It was also found that C12S-QA solubilized a hydrophobic substrate (solid), N,N-dimethyl-3-nitroaniline, in water and then separated it as a precipitate after alkali treatment.
In the present work, quaternary chitosans as water-solublecompounds were prepared based on three-step process. Schiff bases were firstly synthesized by the reaction between the amino groups of chitosan with aliphatic aldehydes followed by a reduction with sodium borohydride (NaBH4) to form N-(alkyl) chitosans. N,N,N-(dimethyl alkyl) chitosans were then obtained by a reaction of chitosan containing N-butyl, N-pentyl, N-hexyl, N-heptyl, and N-octyl substituents with methyl iodide. The compounds were characterized using IR and NMR spectroscopy. Subsequent experiments were conducted to test their antimicrobial activities against the most economic plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens, soft mold disease Erwinia carotovora, fungi of grey mold Botrytis cinerea...
In order to produce a quality grout from LLW using hydraulic cements, proper conditioning of the waste is essential for complete cement curing. Several technologies were investigated as options for conditions. Since the LLW is dilute, removal of all, or most, of the water will significantly reduce the final waste volume. Neutralization of the LLW is also desirable since acidic liquids to not allow cement to cure properly. The nitrate compounds are very soluble and easily leached from solid waste forms; therefore, denitration is desirable. Thermal and chemical denitration technologies have the advantages of water removal, neutralization, and denitration. The inclusion of additives during thermal treatment were investigated as a method of forming insoluable waste conditions.
This report describes results from emissions testing of a prototype diesel engine, developed by Volvo Truck Corporation of Sweden, which uses pilot injection of diesel fuel for compression ignition of alcohol fuel injection for main combustion. In addition to this dual-fuel engine, emission testing was also conducted on a heavy-duty diesel engine of similar design. Both engines were tested over the 1979 13-mode FTP, or shorter versions of this modal test, and over the 1984 Transient FTP as well as an experimental bus cycle. The dual-fuel engine was characterized with methanol, ethanol and ethanol with 30 percent water (wt %). An oxidation catalyst was also used with methanol and ethanol. Emission characterization included regulated emissions (HC, CO, and NOX) along with total particulate, unburned alcohols, individual hydrocarbons, aldehydes, phenols, and odor. The particulate matter was characterized in terms of particle size distribution, sulfate content, C, H, ...
Soils and groundwater beneath an abandoned Process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLS, or dense non aqueous Phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small ...
Soils and groundwater beneath an abandoned process sewer line in the A/M Area of the Savannah River Site (SRS) contain elevated levels of volatile organic compounds, specifically trichloroethylene (TCE) and tetrachloroethylene (PCE), two common chlorinated solvents. These compounds have low aqueous solubilities, thus when released to the subsurface in sufficient quantity, tend to exist as immiscible fluids or nonaqueous phase liquids (NAPLs). Because chlorinated solvents are also denser than water, they are referred to by the acronym DNAPLs, or dense non-aqueous phase liquids. Technologies targeted at the efficient characterization or removal of DNAPL are not currently proven. For example, most DNAPL studies rely on traditional soil and water sampling and the fortuitous observation of immiscible solvent. Once DNAPL is identified, soil excavation (which is only applicable to small ...
Commercial development of oil shale resources will produce vast quantities of processed shale waste. The presence of potentially toxic trace elements, inorganic salts, and potentially toxic residual organic constitutents make the disposal of vast quantities of processed shale a potential environmental problem. To be environmentally acceptable, processed shale disposal must: result in a physically stable structure, prevent or minimize release of potentially toxic compounds, and provide an economically acceptable post-land use. Water is the common element underlying all factors important to the environmental stability of disposed solid waste. The leaching and transport of solubles by water in processed shale embankments may result in degradation of local surface and groundwater quality. The major purpose of this research is to physically model, study, and describe the redistribution and movement of ...
Peculiarities of design of the PGV-1000 horizontal steam generator affecting soluble impurity distribution in its water volume are considered in brief. The results of estimating sodium distribution in different zones of the steam generator are presented. The conclusion is made on the necessity of arrangement of representative measurements of sodium and chloride content in water volume of the steam generator, particularly, in the hot bottom zone for optimization of blow-through flowsheet and its regulations.
A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.
Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble...Full Text Available
Irradiation-assisted stress corrosion cracking (IASCC) of several types of BWR field components fabricated from solution-annealed austenitic stainless steels (SSs), including a core internal weld, were investigated by means of slow-strain-rate test (SSRT), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), and field-emission-gun advanced analytical electron microscopy (FEG-AAEM). Based on the results of the tests and analyses, separate effects of neutron fluence, tensile properties, alloying elements and major impurities identified in the American Society for Testing and Materials (ASTM) specifications, minor impurities, water chemistry, and fabrication-related variables were determined. The results indicate strongly that minor impurities not specified by the ASTM-specifications play important roles, probably through a complex synergism with grain-boundary Cr depletion. These impurities, typically associated with steelmaking and component ...
HIPDM is an "1"2"3I-labeled agent with a distribution in brain reflecting regional perfusion. This compound is neutral and lipid soluble at blood pH and freely crosses the blood-brain barrier. At the lower pH in brain, it picks up a hydrogen ion and becomes positively charged. In this form the molecule is not lipid soluble and it is trapped in brain.
Measurements were completed on the solubility of cupric and cuprous oxides in liquid water and steam at controlled pH conditions from 25 to 400 C (77 to 752 F). The results of this study have been combined with those reported from this laboratory in two previous EPRI reports to provide a complete description of the solubility of these oxides and the speciation of copper dissolved in liquid water and steam as a function of oxidation state, temperature, pH, and in the case of steam, pressure. These constitute the first set of reliable data for cuprous oxide solubility over this range of conditions. For the more intensively studied CuO case, agreement was found between our results and those of previous studies of its solubility in steam, whereas only partial agreement was evident for its solubility in liquid water. For both ...
Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. The model has been implemented with ...
Microwave assisted extraction (MAE) is a combination of a microwave technique and conventional solvent extraction used in the modernization of traditional Chinese medicine. The effective component of medicinal herbs is mostly cellular material which can be released via solvent extraction. The material is diffused to solvents via the porous membrane wall. The structure of herb morphology and characteristics of the solute's molecular weight play an important role in the extraction process of target compounds. Astragalus pieces were chosen for this study in which an ultra-filtration membrane method was used to determine the molecular weight distribution characteristics of Astragalus water extraction liquid in the process of MAE. The fine structure of matrix materials was also characterized by scanning election microscopy (SEM). The phenomenon of mass flow and mass transfer in the plant porous media was discussed along with the enhancement ...
This invention relates to a watersoluble polymer and method for its preparation. The watersoluble polymer exhibits superior thermal stability characteristics when used as an additive in aqueous drilling fluids. The polymer consists of a major portion of a catechol based monomer and a dicarboxylic acid. Other monomers and materials are added to enhance the functional characteristics of the drilling fluid additive. The method of this invention includes the mixing of monomers, polymerization of that mixture and optionally the steps of hydrolysis and sulfonation.
Selected sera from cattle naturally infected with Brucella abortus precipitate watersoluble antigens extracted by sonication from B. abortus. One of these antigens resembles antigen E (Baughn and Freeman)...Full Text Available
The performance of the Magma Power Company's reinjection well No. 46-7 at East Mesa has been examined. Water was cooled to 100/sup 0/F(+-) to simulate total heat extraction and then tested using membrane filter flow procedures. The cooled water contains particles which are in the high colloid size range, and formation impairment by these particles is unlikely. There is evidence that acid soluble corrosion products and calcium compounds constitute about two thirds of the particulates, and that the acid insoluble residue contains precipitated silica, insoluble corrosion products, and possibly formation fines carried in the produced water. Under stabilized conditions, the suspended solids content of the water is less than 2 parts per million. However, during the frequent production well start ups, a higher concentration of suspended solids is carried in ...
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.
The compost bioreactor ('anaerobic cell') components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, ...
The economic feasibility of using granular activated carbon (GAC) to remove organic contaminants from industrial and municipal wastewater is contingent upon its reuse during multiple adsorption-regeneration cycles. The most common process for the regeneration of GAC is the thermal method. Drawbacks associated with thermal regeneration include a 5--10% loss of carbon due to oxidation and attrition, a decrease in adsorption capacity, and high energy costs. The purpose of this study was to investigate the regeneration of GAC using hydrothermal technology. Phenol contaminated and non-contaminated GAC samples were regenerated using supercritical water (411 deg C and 26.2 MPa) with dissolved oxygen concentrations of 0 mg/L, 5 mg/L, and 100 mg/L. For comparative purposes, GAC was regenerated using subcritical water (300 deg C and 12.4 MPa) with a dissolved oxygen concentration of 5 mg/L. Regenerated GAC samples were evaluated in terms of adsorption ...
The chemical thermodynamic concepts used in the calculation of solubility data of silica (quartz) are presented taking into account the PVT characteristics of water. The temperature-dependence trends between the thermodynamically calculated and the experimental quartz solubility data are very similar, but the values are widely different at high temperatures. The experimental solubility, especially along the saturation curve at high temperature and thermodynamic data for silica need to be reevaluated in order to use silica chemistry to understand geological processes. There could exist a wide range of values for silica solubility at a specified temperature, depending upon the amount of water in the reaction vessel. Thus the silica contents in geothermal fluid, in general, cannot be used as a geothermometer to estimate the reservoir temperature. The derivation of ...
The solubility behavior of solid residues from the heat treatment of domestic rubbish was examined by simulated precipitation in laboratory lysimeters. The precipitation corresponded to the average amount of rain in West Germany and was applied at different time periods. Specific soil characteristics, the value of k/sub f/ and the water retention capacity was determined in this way. In parallel with the lysimeter flood ions, extraction (by batch process) was done, in order to find the maximum solubility of the materials used. It was found that for pyrolysis residues from reactor temperatures of 450/sup 0/ to 1000/sup 0/C, a greater solubility was measured than for slag from combustion. The eluates from these residues gave information about the degree of contamination or on the solubility of the measured parameters and materials in organoleptic, physical, organic and inorganic ...
The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public.
A series of pyrrolo[2,3-d]pyrimidine-2,4-diones and intermediates was tested for anticonvulsant activity in mice. Eleven of the 15 compounds possessed anticonvulsant activity against pentylenetetrazol-induced convulsions. One compound afforded more anticonvulsant protection against pentylenetetrazol than did trimethadione (67 and 50%, respectively). A suspension of this compound was found to be as effective as a solution in producing anticonvulsant activity. The results suggest that the nitrile analogs were more potent compared to the carbamyl analog due to higher lipid solubility. PMID:7373552
The effects of the time and temperature of alkaline pretreatment and the time and temperature of the carboxymethylation of peat in 2-propanol on the concentration of carboxymethyl groups and the solubility of the resulting products in water and an aqueous alkali solution were studied. The viscosity characteristics of the aqueous and aqueous alkaline solutions of peat carboxymethylation products were studied.
Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.
An experimental investigation was conducted to evaluate the effect of three different oxygenated compounds, diglyme, diethyl maleate and dibutyl maleate, on emissions from a Volkswagen 1.9 litre, turbocharged, direct injection diesel engine. Sampling was performed using a mini-dilution tunnel technique to obtain particulate matter and a Fourier transform infrared (FTIR) spectrometer for gaseous emissions. The particulate samples were analysed using thermal analysis and Soxhlet extraction to determine the fraction of volatile and soluble organic material respectively. All three oxygenated compounds were found to be effective at reducing particulate emissions, with the maleate compounds being more effective overall than the diglyme. Analysis of the relative contributions of changes in the soot and soluble organic fraction (SOF) to the reduction of particulate matter indicated that, ...
The nature of interaction of some boromagnesium minerals with water is studied, the main stages of interaction are established. The methods of thermo-gravimetric, X-ray phase and chemical analyses are applied to state intermediate and final phases of magnesium borate interaction with water. ''Preobrazhenskite'' - ''inderite'' paragenesis is established. The notion ''magnesium borate solubility'' is shown to be senseless.
Acidic constituents in crude oil are associated with the formation of stable emulsions during production and present a challenge for efficient oil recovery and processing. Acid molecules, including naphthenic acids and acidic sulfur in crude oil cause corrosion in refineries and pipelines. Naphthenic acids are also significant because of their surface activity and marginal watersolubility, so that they may leach to wastewaters and cause adverse environmental effects. Acidic components of oil are not limited to carboxylic acids but also molecules that contain sulfur and nitrogen. As such, an improved understanding of the chemistry and physics of petroleum at the molecular level is needed in order to understand the range of problems associated with acidic oil components and to design better solutions. The applications of negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for ...
Wood plastic composites are prepared under radiation of "6"0Co gamma source with simul, a low grade wood of Bangladesh using a watersoluble monomer acrylamide (AM) mixed with a swelling solvent methanol, water or methanol/water (1:1) at different compositions in the presence of a number of additives and co-additives such as NVP (N-vinylpyrrolidone), TPGDA (tripropylene glycol diacrylate), TMPTA (trimethylol propane triacrylate), sulfuric acid, urea and copper sulfate. Polymer loading (PL) and tensile strength (TS) of the composites are measured. The role of these additives on the composites is also discussed. It is observed that nitrogen-atom containing-materials like urea, NVP and AM produce composites with the highest mechanical strength, and incorporation of copper into this system provides additional property of protection and preservation of the composites against attacks by insects and microbes. ...
This communication reports the formation of complex Langmuir monolayer at the air-water interface by charge transfer types of interaction with the watersoluble N-cetyl Formula Not Shown -trimethyl ammonium bromide (CTAB) molecules doped with rosebengal (RB), with the stearic acid (SA) molecules of a preformed SA Langmuir monolayer. The reaction kinetics of the formation of RB-CTAB-SA complex monolayer was monitored by observing the increase in surface pressure with time while the barrier was kept fixed. Completion of interaction kinetics was confirmed by FTIR study. This complex Langmuir films at the air-water interface was transferred onto solid substrates at a desired surface pressure to form multilayered Langmuir-Blodgett films. Spectroscopic characterizations reveal some molecular lev...
In this work, a water-soluble polymer, polyethylenimine (PEI) was used for the simultaneous separation and preconcentration of trace Cu and Mn prior to their determination by flame atomic absorption spectrometry. For this purpose, the sample and the PEI solution were mixed and the metal-bound polymer was precipitated by adding acetone. The precipitate was separated and dissolved in a minimum amounts of water and aspirated into a flame AAS. By increasing the ratio of the volumes of sample to water used in dissolving the precipitate, the analyte elements were concentrated as needed. The sorption is quantitative in the pH ?6. Detection limits were 5.2 ?g/L for Cu and 5.4 ?g/L for Mn. This method is simple, fast and precise.
A discussion is given concerning the transformation in acid medium of curite into copper-, nickel- and cobalt-uranylphosphate. From chemical, differential thermal and thermogravimetric analyses, the crystal-chemical formula are calculated as: Cu(UO/sub 2//PO/sub 4/)/sub 2/.8H/sub 2/O, Ni(UO/sub 2//PO/sub 4/)/sub 2/.7H/sub 2/O and Co(UO/sub 2//PO/sub 4/)/sub 2/.7H/sub 2/O. The two last compounds crystallize in the triclinic system with space group P1 or P1(overscore) and the first one crystallizes in the tetragonal system with space group P4/nmm. The cell parameters are calculated. From solubility data, the solubility products are computed as 10sup(-12.8), 10sup(-9.5) and 10sup(-9.9) for the copper-, nickel- and colbalt-compound respectively. The electrokinetic properties of the three species are closely similar to those of natural meta-torbernite: the zeta-potential is negative and the point of zero ...
A discussion is given concerning the transformation in acid medium of curite into copper-, nickel- and cobalt-uranylphosphate. From chemical, differentiel thermal and thermogravimetric analyses, the crystal-chemical formula are calculated as: Cu(UO_2/PO_4)_2.8H_2O, Ni(UO_2/PO_4)_2.7H_2O and Co(UO_2/PO_4)_2.7H_2O. The two last compounds crystallize in the triclinic system with space group P1 or P1(overscore) and the first one crystallizes in the tetragonal system with space group P4/nmm. The cell parameters are calculated. From solubility data, the solubility products are computed as 10sup(-12.8), 10sup(-9.5) and 10sup(-9.9) for the copper-, nickel- and colbalt-compound respectively. The electrokinetic properties of the three species are closely similar to those of natural meta-torbernite: the zeta-potential is negative and the point of zero charge be reached cannot in the pH-range 2 to 9.
Hydrothermal oxidation (HTO) is a promising technology for the treatment of aqueous-fluid hazardous and mixed waste streams. Waste streams identified as likely candidates for treatment by this technology are primarily aqueous fluids containing hazardous organic compounds, and often containing inorganic compounds including radioisotopes (mixed wastes). These wastes are difficult and expensive to treat by conventional technologies (e.g. incineration) due to their high water content; in addition, incineration can lead to concerns related to stack releases. An especially attractive potential advantage of HTO over conventional treatment methods is the total containment of all reaction products within the overall system. The potential application of hydrothermal oxidation (HTO) technology for the treatment of DOE hazardous or mixed wastes has been uncertain due to concerns about safe and efficient operation of the technology. In ...
NIST radon standards are hermetically sealed polyethylene capsules filled with {sup 226}Ra solution. Recently, four new series of standards with activities 5, 50, 500, and 5000Bq were prepared. The measured emanation fraction agrees with a calculation that accounts for the radon accumulated inside the polyethylene walls of the capsule. Obtained solubility of radon in polyethylene is approximately 45 of the solubility of radon in water. The radon diffusion coefficient in low-density polyethylene is 7.2x10{sup -8}cm{sup 2}/s.
A method is proposed for deriving hydrolized polyacrylonitrile from a water-based alkali solution. This process is meant to improve the thermal stability of clay drilling solutions by employing the hydrolized product to treat aliphatic non-water-soluble C/sub 8/-C/sub 16/ spirits in an organic dispersant during the presence of acidity and while the solution is being heated.
A method is proposed for making a drilling mud, which includes mixing of an aqueous solution of a watersoluble acrylic polymer with clay. It is distinguished by the fact that in order to reduce the corrosion activity of the clay solution, the dry clay is slaked in an aqueous solution of partially hydrolized polyacrylonitrile with the following component relationship (in percent by mass): clay, 3 to 10; hydrolized polyacrylonitrile, 3 to 5 and water, the remainder.
Decommissioning of radiological and nuclear installations is for this century the new challenge. One of the performance criteria is the reduction of total quantities of radioactive materials (liquid or solid) arising from dismantling and decontamination of radiological and nuclear installations. In this work we present a new application of the watersoluble polymers used as: - flocculation agents in treatment and conditioning process within the management of radioactive liquid materials; - strippable coatings on solid materials based on the watersoluble polymers. The parameters of watersoluble polymers made in our Institute by radiation processing have been analysed, namely the molecular average weight, composition, and efficiency of utilization of these polymeric materials as well as the content of ash, additives, decontamination factor, consumption per ...
The absorption of carbonyl sulfide in aqueous methyldiethanolamine (MDEA) was studied over a range of temperatures and MDEA concentrations. MDEA is commonly used for selective absorption of hydrogen sulfide in the presence of carbon dioxide. However, sulfur in the form of COS may also be present and it is necessary that estimates of absorption rates of this compound be made. The objective of this study is to determine the physiochemical properties needed to predict COS absorption rates in aqueous MDEA. Free gas solubility and the diffusivity of COS in MDEA solutions were measured over the temperature range 15 to 40{sup 0}C for MDEA concentrations up to 30 weight per cent using the nitrous oxide analogy method. Solubilities were measured volumetrically in an equilibrium cell and diffusivities were measured using a laminar liquid jet absorber. The kinetics of the reaction between COS and MDEA were studied by measuring ...
Micronutrient deficiencies in flooded rice have been recognized with increasing frequency in recent years. Zinc deficiency is the most widespread disorder, followed by Fe, Mn, and Cu deficiencies. Boron and Mo deficiencies have not been reported in field culture. The peculiar characteristics of a flooded soil are: 1) a layer of standing water; 2) absence of oxygen; 3) a soil profile largely in a reduced chemical state; 4) the presence of large biological carbon dioxide excesses; 5) the presence of high concentrations of soluble Fe"+"+ and Mn"+"+; 6) alteration of soil pH; 7) the presence of toxic substances; 8) increased soluble Na"+, K"+, Ca"+"+, Mg"+"+, NH_4"+, HCO_3"-, H_2PO_4"-, and Si(OH)_4 in the soil solution. Micronutrient availability in flooded soils is affected by: 1) increased solubility of relatively insoluble minerals due to dilution effects; 2) pH changes in relation to ...
The production of water from a subterranean formation is reduced by contacting the formation with a water dispersible hydrophilic organic polymer having a molecular weight greater than 100,000 and containing carboxyl functionality and a crosslinking composition comprising water, a zirconium compound having a value of 4+, an alpha-hydroxy acid and an amine compound.
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 70-87%. For convenience of isolation the readily water-soluble ...
As a result of nuclear power plant accidents, large areas receive radioactive inputs of Cs-137. This cesium accumulates in herbs growing in such territories. The problem is whether the herbs contaminated by radiocesium may be used as a raw material for medicine. The answer depends on the amount of Cs-137 transfered from the contaminated raw material to the medicine. We have presented new results of the transfer of Cs-137 from contaminated Digitalis grandiflora Mill. and Convallaria majalis L. to medicine. We found that the extraction of Cs-137 depends strongly on the hydrophilicity of the solvent. For example 96.5%(vol.) ethyl alcohol extracts less Cs-137 (11.6%) than 40%(vol.) ethyl alcohol or pure water (66.2%). The solubility of the cardiac glycosides is inverse to the solubility of cesium, which may be of use in the technological processes for manufacturing ecologically pure herbal medicine.
Abstract Jicama (Pachyrhizus erosus L.) is a root-based legume that has been cultivated in Mexico for centuries. Pectic polysaccharide from de-starched jicama pomace was extracted using an autoclave-assisted process and physicochemically characterized. The extracted polysaccharide (1.0 g L-1) was used for the formation of polyelectrolyte complexes (PECs) with water-soluble chitosan (WSCh; 0.5, 1.0 and 2.0 g L-1). The extraction yield of jicama pectic polysaccharide was 22.8 wt% (dry basis) and infrared spectroscopic analysis showed that it was methoxylated to a small degree. Thermogravimetric analysis indicated that this biopolymer was very stable, its weight loss being 51.2% after heating at 479 C. Anion-exchange chromatography showed it to have a wide and heterogeneous charge density. Th...
Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material galvanically coupled with a noble intermetallic compound of ...
Alloying elements such as Fe and Cr are generally considered to be effective even in small quantities for corrosion resistance of Zircaloy-4. The maximum total solubility of Fe + Cr in a Zr-Sn matrix has been reported to be very low. Therefore, most of these elements are observed in the form of ternary Zr-Fe-Cr-type precipitates. To clarify the effects of precipitates on corrosion property, Zr-1.3 Sn-(Fe,Cr) alloys containing Fe + Cr from 45 up to 180 ppm (the Fe to Cr ratio is about 2) were melted from pure zirconium (X-bar Zr and EB-Zr) and pure alloying elements. They were subjected to corrosion testing in 633 K water and microstructural analysis. It was found that precipitate-free materials showed much larger weight gains than precipitate-containing materials even at the same alloy compositions. Subsequently, a corrosion test on the precipitate-free material galvanically coupled with a noble intermetallic compound of ...
Analytical procedures are described for the determination of organic compounds, metals and radioisotopes in environmental materials, human tissues, urine, feces, and waste water.
In preparation for studying the hydrolytic degradation of Estane 5703 in the plastic-bonded explosive PBX 9501, the sorption (solubility) and diffusion of water in PBX 9501 and each of its components are studied experimentally and modeled theoretically. Experiments are reported that measure the weight gain or loss due to a change in the relative humidity (RH). For all of the components, the equilibrium amount of water sorbed per gram of sample is linear in the RH at low relative humidities but curves upwards at higher relative humidities. This behavior is modeled with a water cluster model. Diffusion coefficients are determined by modeling the time dependence of the water concentrations assuming Fickian diffusion, and that fits the data for some of the materials. However, all the samples t...
Assessments of drinking water safety rely on the assumption that ingestion represents the principal route of exposure. A review of the experimental literature revealed that skin penetration rates for...Full Text Available
Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives. (author) 1 tab.
Distribution of Lipiodol within hepatic tumor was evaluated using serial computed tomography. Imagistic Lipiodol transition into the tumor via hepatic artery was slower than that of watersoluble contrast medium, spreading to central part first and turn to peripheral part of the tumor. This method was thought to be useful to clarify Lipiodol distribution in hepatic tumor and to decide the method or necessity of additional trans-arterial therapy. (author).
...Species - see CITES Trade of Dangerous Chemicals Transport and Environment U Urban Environment Use of natural resources V Volatile Organic Compounds W Waste Landfills Waste electrical and electronic equipment - see WEEE Waste incineration Waste legislation - reporting Waste management planning Waste oils Waste shipments Waste water - see Urban waste waterWater Bathing Water Drinking water Floods Marine environment Urban waste waterWater Framework Directive WEEE - Waste Electric and Electronic Equipment Wildlife ...
Manganese is an essential metal of toxicologic concern primarily because of exposure via inhalation. Environmental forms of Mn exist mainly as insoluble oxides, yet much of the research information available relates to the soluble salts. In the present study, adult male Sprague-Dawley rats were intratracheally instilled with either soluble MnCl/sub 2/ or insoluble Mn/sub 3/O/sub 4/ labeled with /sup 54/Mn. Lungs and other major organs were sampled over a span of 3 mo after dosing with the respective chemicals, which were equivalent to 8 ..mu..Ci and 1 ..mu..mol of manganese in 0.2 ml of buffer. There was rapid clearance of Mn from the lungs in the case of both chemicals; the chloride cleared at an initial rate of nearly four times that of the oxide. Despite this early difference, the amount of /sup 54/Mn remaining in the lungs after 2 wk was similar for both compounds. The level of /sup 54/Mn in the liver, kidney, spleen, ...
Chronic exposure to uranium compounds such as UO{sub 2} and U{sub 3}O{sub 8} led to the development of a methodology, based on the recommendation of ICRP, involving four main steps: the measurement of the uranium concentration and the particle size distribution at the workstation, the assessment of physico-chemical properties of the compound, the study of in-vitro solubility using a chemical test and the monitoring of workers. Results and comments on UO{sub 2} and U{sub 3}O{sub 8} are given. (author)
Previous studies from this laboratory have shown that certain N-substituted phthalimides (NSPs) exhibit GA-like activity in a range of specific bioassays and that bioactive NSPs compete with ({sup 3}H)-GA{sub 4} for soluble binding sites in cucumber homogenates. As such, these compounds may prove useful in the purification and characterization of GA receptor proteins. To this end, five azido-NSPs have been synthesized and are currently being screened for biological activity and photochemical stability. Three azido-NSPs elicit {alpha}-amylase production in barley half-seeds and stimulate tissue elongation in d{sub 5} maize, lettuce, sunflower, and soybean. Further evaluations are in progress and these data as well as the utility of these compounds as photo-affinity ligands will be discussed.
Ions of rare earth elements (r.e.e.) have been found to form with benzilic acid and rhodamine B precipitates hardly soluble in water and extractable by toluene. The conditions of La and Pr determination by extraction-spectrophotometry method are studied. Relative square deviation does not exceed 0.027 and 0.034 respectively. The method can be used for determination of other cerium sub-group r.e.e. in their salts and cannot be employed for determination of lighter r.e.e. in the presence of heavier r.e.e., because the latter form low soluble precipitates capturing the r.e.e. situated in the beginninq of the r.e.e. series.
Functional properties of commercial and membrane processed pea protein isolates (PPI) prepared from yellow peas were investigated. Four protein isolates were prepared from yellow pea flour using water and KCl extractions at 25^oC followed by ultrafiltration and diafiltration (UF and DF) at pHs of 7.5 and 7.5 or 6 respectively. Following assessment of compositional attributes; solubility, foaming, flow and dynamic rheology, emulsification ability and heat-induced textural and rheological properties of prepared PPIs and a commercially available PPI were tested and compared. Membrane purification of proteins resulted in 28% to 68% reduction in phytic acid and enhanced, comparatively, the tested functional properties. Solubility of membrane processed PPIs, at all tested pHs, was superior and t...
This paper discusses the remote plugging of leaks in inaccessible pipework, with main reference to small leaks which frequently appear in ancillary cooling water circuits of nuclear reactors. Initially developed to cure problems of the pre-stressed concrete pressure vessels of UK reactors, the ZORIC sealant has been used to repair leaking biological shield pipework on six CANDU reactors. ZORIC is based on a water-soluble epoxy resin and an aqueous suspension of a refined mineral clay. This paper describes the evolution of the sealant, the qualification and testing program, and their application to CANDU reactor systems. 2 refs., 6 figs.
Olive oil mill wastewaters (OMW) cause disposal problems because they contain powerful pollutants such as phenolic compounds. Complete biodegradation or removal of these compounds is hardly achieved by a single treatment method. In this work, we investigated 2 integrated technologies for the treatment of the recalcitrant contaminants of OMW, allowing water recovery and reuse for agricultural purposes. (Author)
Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the ...
We have studied freshly prepared lysozyme solutions in heavy water for two NaCl concentrations as a function of temperature. Lysozyme solubilities in this solvent are determined by static light scattering. By small angle neutron scattering, we evidence that interactions between lysozyme molecules are characterized by a second virial coefficient A{sub 2} whether the solution is under-saturated or supersaturated. From the variation of A{sub 2} as a function of temperature we have evaluated the enthalpy corresponding to the interaction between lysozyme molecules. We show that the interactions between protein molecules are higher in heavy water than in light water. (authors). 13 refs., 3 figs.
Production treatment chemicals represent a diverse collection of chemical classes, added at various points from the wellhead to the final flotation cell, to prevent operational upsets and enhance the separation of oil from water. Information in the literature indicates that while many treatment chemicals are thought to partition into oil and not into the produced water, there are cases where a sufficiently watersoluble treatment chemical is added at high enough concentrations to suggest that the treatment chemical may add to the aquatic toxicity of the produced water. A study was conducted to evaluate the potential effect of production treatment chemicals on the toxicity of produced waters using the US EPA Seven-day Mysidopsis bahia Survival, Growth and Fecundity Test. Samples of produced water were collected and tested for toxicity from ...
The role of atmospheric urea on the biogeochemical cycle of WaterSoluble Organic Nitrogen (WSON) in the Eastern Mediterranean was assessed by collecting and analyzing wet and dry deposition samples and size segregated aerosols during a one year period (2006). In rain water volume weighted mean (VWM) concentration of urea was found equal to 5.5mM. In atmospheric particles the average concentration of urea in coarse and fine mode was 0.9+/-1.9nmolNm^-^3 (median 0.0nmolNm^-^3) and 2.2+/-3.0nmolNm^-^3 (median 1.1nmolNm^-^3), respectively. The percentage contribution of urea to WSON fraction was 0% and 20% in coarse and fine particles respectively. On an annual basis 0.81mmolm^-^2 and 1.78mmolm^-^2 of urea were deposited via wet and dry deposition, contributing to WSON by 10% and 11% respectiv...
The authors observed euhedral crystals in Manatee soil in a citrus grove in St. Lucie County, Florida. The material was identified as gypsum (CaSO/sub 4/ /times/ 2H/sub 2/O) using x-ray diffraction and infrared spectra. Photomicrography and scanning electron microscopy revealed that gypsum accumulated both in old root channels and within citrus root tissue of the Btg horizon. The subsurface horizons had elevated sulfate levels, a low initial pH, a drop (0.5 unit) in pH upon air-drying. Electrical conductivity paralleled the concentration of water-soluble sulfate. High levels of calcium and sulfate occurred for horizons above the water table. This accumulation is attributed to groundwater bearing these ions and subsequently discharging them to the overlying soil. Dead citrus roots appear to act as wicks to aid water transfer from lower to higher horizons. The roots and their empty channels provide spaces in which the gypsum ...
We propose and demonstrate a facile room-temperature synthetic method for obtaining water-soluble magnetic Fe3O4 nanoparticles (NPs) by combining the in situ synthesis and decomposition of a magnetic polymer hydrogel. The Fe3O4 NPs with average diameters of 6.3-8.3nm were synthesized in a cross-linked polyacrylamide (PAAm) hydrogel by coprecipitating iron ions. The decomposition of the magnetic polymer hydrogel by an aqueous solution of sodium hydroxide led to the transfer of Fe3O4 NPs into the aqueous medium. The NPs can be dispersed stably in water for more than three months. The Fe3O4 NPs were characterized by X-ray photoelectron spectra (XPS), X-ray powder diffraction (XRD), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The saturation magn...
Plutonium isotopes (239Pu and 238Pu, and 241Am) with a total activity of 269 kBq were accidentally deposited in a puncture wound of the right index finger of a nuclear worker at the Mayak Production Association. Tissues surrounding the wound site contaminated with radionuclides were excised 4.5 h after the injury. Residual contamination within the wound amounted to 0.05% of the initial contamination. The 10-d therapy with CaNa3-diethylene triamine pentaacetate acid (CaNa3-DTPA) was performed in parallel with in vivo measurements of the wound site and daily urine bioassays. The wound intake of radionuclides was consistent with two forms of radioactive materials detected within the wound site, i.e., solublecompounds and a large fragment, which was completely removed by excision. On day 9 after the injury, the clearance rate from the wound site was 1.8 times higher than the rate predicted by the National Council on Radiation Protection and ...
Manganese is a common contaminant of mine water and other waste waters. Due to its high solubility over a wide pH range, it is notoriously difficult to remove from contaminated waters. Previous systems that effectively remove Mn from mine waters have involved oxidising the soluble Mn(II) species at an elevated pH using substrates such as limestone and dolomites. However it is currently unclear what effect the substrate type has upon abiotic Mn removal compared to biotic removal by in situ micro-organisms (biofilms). In order to investigate the relationship between substrate type, Mn precipitation and the biofilm community, net-alkaline Mn-contaminated mine water was treated in reactors containing one of the pure materials: dolomite, limestone, magnesite and quartzite. Mine water chemistry and Mn removal rates were ...
Porcine pancreatic lipase immobilized on celite particles has been employed as a catalyst for the esterification of dodecanol and decanoic acid in a predominantly organic system. Solvent influence on the equilibrium position and on the catalyst activity has been studied using 20 solvents, including aliphatic and aromatic hydrocarbons, ethers, ketones, nitro- and halogenated hydrocarbons, and esters. The equilibrium constant for esterification correlates well with the solubility of water in the organic solvent, which in turn shows a good relationship with a function of Guttman's donor number and the electron pair acceptance index number of the solvent. This may be rationalized in terms of the requirements for solvation of water and of the reactants. The catalyst activity, measured as the initial rate of the esterification reaction, is best correlated as a function of both n-octanol-water partition ...
Lead is a heavy metal which is widely used in paint industry, pigments, dyes, electrical components and electronics, plastic chemicals and in various other things. Since some of the lead salts are soluble in water, lead presents a potential threat to aquatic organisms. Studies dealing with invertebrates include those on mortality, growth and lead uptake in Lymnaea palustris and bioaccumulation of heavy metals in oysters and mussels. Little information exists regarding the effect of lead on the fresh water crustaceans. Hence the present investigation has been undertaken to study the uptake and loss of lead on exposure to subtoxic levels or organic and inorganic lead.
Perylene bisimides (PBIs) represent an important class of organic n-type semiconductors exhibiting a relatively high electron affinity among large-band-gap materials. Herein synthesis and characterization of several unsymmetrical N-substituted PBI dyes is presented and the thermotropic behavior, which is strongly affected by the respective N-substituents was investigated. Two different series of highly soluble and fluorescent derivatives have been synthesized: (1) PBIs bearing swallow-tailed alkyl chains, different in size or (2) one swallow-tailed alkyl chain and one branched oligoethylenglycolether. Synthesis of these PBIs is generally feasible by two distinct divergent synthesis approaches. Thermotropic behavior was studied by DSC, POM and XRD measurements. Inherent {pi}-{pi} interactions between cofacially orientated perylene molecules and the elliptic shape of the molecule favor the ordering in columns and self-organized architectures. Among them hexagonal ...
Miscanthus is a potential feedstock for the production of biofuels. Lignocellulosic biomass is not soluble in conventional solvents, but Miscanthus and other lignocellulosic biomass have reasonable solubilities in some ionic liquids. The solubility of Miscanthus in a variety of hydrophilic ionic liquids was measured as a function of particle size, temperature and time for dissolution. In addition to temperature and time, the ionic liquid anion has a significant effect on solubility and rate of dissolution. The moisture content of Miscanthus lowers its solubility in certain ionic liquids. Chloride, acetate, and phosphate-based ionic liquids favor solubility. A tentative correlation for the solubility of Miscanthus is proposed in terms of Abraham solvation parameters obtained from quantum-ch...
Extra-fine powdered activated charcoal has been used as stationary phase (coating layer) in solid-phase microextraction (SPME). The efficiency and reliability of the prepared device have been investigated for the extraction of some volatile organic compounds such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) from the headspace of water samples. Monitoring of the extracted compounds and further quantitative analysis of the real samples have been performed by capillary GC-FID. Effects of several factors such as temperature, addition of salt, and stirring speed on extraction efficiency and exposure time have been studied. Under optimum conditions, extraction recoveries for these compounds from 50 mL water were >95%. The calibration graphs were linear in the range 5 to 10{sup 4} pg mL{sup -1} and the detection limit for each BTEX compound was 1.5-2 ...
The results of experimental studies on the contribution of zoogenic debris to transformation of soil properties in the southern taiga subzone of Central Siberia are analyzed. They show that water-soluble carbon outflow from the forest litter increases by 21-26% upon a Siberian moth invasion, with this value decreasing to 14% one year later. The burning of forest in an area completely defoliated by the pest leads to changes in the stock, fractional composition, actual acidity, and ash element contents of the litter. The litter-dwelling invertebrate assemblage is almost completely destroyed by fire and begins to recover only after two years. PMID:18491565
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.
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.
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 and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.
Radon-222 has been measured in natural gas produced from experimental geopressured-geothermal test wells. Comparison with published data suggests that while radon activity of this unconventional natural gas resource is higher than conventional gas produced in the gulf coast, it is within the range found for conventional gas produced throughout the US. A method of predicting the likely radon activity of this unconventional gas is described on the basis of the data presented, methane solubility, and known or assumed reservoir conditions of temperature, fluid pressure, and formation water salinity.
Water-soluble, ethanol-insoluble extracts prepared from several medicinal herbs of the Araliaceae and other families were tested for their radioprotective activity by either measuring 30 days survival rates (a commonly applied method) or counting the thrombocytes 14 days after irradiation (an improved method) in mice. The extracts were i.p. injected once within 4 min after the whole body X-ray irradiation. Of 12 materials examined, Aralia elata, Angelica acutiloba and Morus bombysis seemed to be good starting materials for preparing radioprotective substance(s) because of their relatively high specific activity and high yields of the extracts. (author).
Elbistan lignite has been found to contain 50.1 wt% (daf) humic acid. The i.r. spectrum of this lignite, however, indicates the absence of free carboxyl groups. Treatment with mineral acids, however, regenerates the carboxyl groups. A product containing 18.8 wt% N (daf) has been obtained by treatment of HNOat3 treated Elbistan lignite in aqueous ammonia for 4 h at 165 C and under oxygen pressure. Water-soluble and active nitrogen tests indicate that such products may have the properties of slow-release nitrogenous fertilizers. (33 refs.)
Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme ...
The activated charcoal is very appreciates for the water treatment. It do not generate by-product of treatment. In return it is saturated after some time and may releases pollutant compounds. When and how to get to its regeneration?.
This paper addresses the quantification of human exposure to volatile organic compounds (VOC's) as a result of mass transfer from tap water to indoor air. A three-compartment model is developed and used to simulate the 24-h concentration profile within the shower, bathroom, and remaining household volumes of a dwelling. Mass transfers from water to air are derived from measured data for radon and adjusted to account for the difference in mass-transfer properties for VOC's. A preliminary data base for household parameters is used to calculate a range of concentrations and human exposures in U.S. dwellings. The model is used to estimate exposure factors for seven compounds-chloroform, ethylene dibromide, dibromo-chloropropane, methylchloroform, perchloroethylene, trichloroethylene, and carbon tetrachloride. The calculated ratio of indoor-air exposure to tap water concentration is ...
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).
As part of the general QC/QA management of the k_0-standardization, three types of 'SMELS' (synthetic multi-element standards) are being developed to check the performance of k_0-NAA when implemented in a laboratory. Phenol-formaldehyde resin is proposed in this paper as the matrix of choice. Based on previous work, this material could be prepared with sufficient purity so as to make interferences with the spiking elements negligible. The matrix was found to be adequately resistant towards high neutron flux irradiation. A selection was made of compounds, soluble in ethyl alcohol, for spiking the prepolymer ethanolic solution with the elements of interest. Finally, some prototypes were prepared and a satisfactory homogeneity of the spiked elements was found for 50 mg sample intake.
In this work it is made a study of the structure and electric properties of chlorate polyethylene (PE-CI) with double and simple bonds obtained by continuous plasma with resistive coupling to 13.5 MHz. The synthesis conditions are power between 10 and 14 W and pressure of (6-7) x 10{sup -2} Torr. The synthesized PE-Cl in that way is soluble in acetone what indicates that probably is formed of short chains and not it shows the generalized inter crossing that is presented in some syntheses by plasma and that it can degrade the electric properties of these polymers. The IR and XPS analysis show the vibration of the C-C, C=C and C-CI bonds. The morphology of the polymer after being dissolved shows a compact and flat configuration. The electric conductivity has an approximately lineal behavior in an interval of 35 to 90% of relative humidity. (Author)
The redistribution of implanted As and Sb following metal-silicide formation of Pt, Pd, and Ni has been studied. The phases of the silicides used were PtSi, Pd/sub 2/Si, and NiSi. Investigations with Rutherford backscattering analysis showed that after the formation of the silicides, the Sb was always found in the silicide layer near the surface of the samples, whereas PtSi and Pd/sub 2/Si caused a partial rejection of As for implanted doses of 2 x 10/sup 15/ cm/sup -2/ and higher. No rejection of As was found after the formation of NiSi. The results are discussed in terms of solid solubilities and impurity-metal compound formation. The data presented has implications in the fabrication of Ohmic contacts and the adjustments of the heights of Schottky barriers on silicon.
The redistribution of implanted As and Sb following metal-silicide formation of Pt, Pd, and Ni has been studied. The phases of the silicides used were PtSi, Pd_2Si, and NiSi. Investigations with Rutherford backscattering analysis showed that after the formation of the silicides, the Sb was always found in the silicide layer near the surface of the samples, whereas PtSi and Pd_2Si caused a partial rejection of As for implanted doses of 2 x 10"1"5 cm"-"2 and higher. No rejection of As was found after the formation of NiSi. The results are discussed in terms of solid solubilities and impurity-metal compound formation. The data presented has implications in the fabrication of Ohmic contacts and the adjustments of the heights of Schottky barriers on silicon.
The systems CH_3COHNC_6H_4CH_3-HI-H_2O, CH_3CONHC_6H_4CH_3-HIO_3-H_2O, CH_3CONHC_6H_4CH_3-H_5IO_6-H_2O have been studied by the solubility method. It has been ascertained that the systems containing periodic and iodic acids are referred to systems of simple eutonic type. Formation of compound of o-methylacetanilide with iodic acid of equimolecular composition has been proved. Concentrational boundaries of its existence in solutions have been established, its certain physicochemical characteristics being determined.
Objectives of the program are to understand the mechanisms of coal liquefaction, to determine the role of catalysts in the direct conversion of coal to liquids, to determine the mechanism of catalyst deactivation and to explore slurry phase catalyst systems. Specific projects include: short-contact time coal liquefaction, mineral matter effects and catalyst studies. During this period, work was performed on: (1) the stability, at reaction temperature, of a recycle solvent obtained from the Lummus Two Stage Liquefaction facility, (2) reactions of preasphaltenes and asphaltenes prepared under various reaction severities, (3) the evaluation of the catalyst level detector installed at the H-Coal facility, (4) the characterization of oil soluble metal compounds with respect to hydrogenation activity, and (5) characterization, deactivation and regeneration of catalysts obtained from both the H-Coal and Lummus facilities.
The earthworm gut provides ideal in situ conditions for ingested heterotrophic soil bacteria capable of anaerobiosis. High amounts of mucus- and plant-derived saccharides such as glucose are abundant in the earthworm alimentary canal, and high concentrations of molecular hydrogen (H2) and organic acids in the alimentary canal are indicative of ongoing fermentations. Thus, the central objective of this study was to resolve potential links between fermentations and active fermenters in gut content of the anecic earthworm Lumbricus terrestris by 16S ribosomal RNA (rRNA)-based stable isotope probing, with [13C]glucose as a model substrate. Glucose consumption in anoxic gut content microcosms was rapid and yielded soluble organic compounds (acetate, butyrate, formate, lactate, propionate, succi...
This is a report of extraction and identification of 1-O-alkyl glycerol present in the dried leaves of Bauhinia scandens. Fifty percent aqueous ethanolic extract of the plant at room temperature was fractionated over petroleum ether and diethyl ether. The diethyl ether soluble fraction showed positive bioactivity in Brine Shrimp bioassay. Isolation and purification of the active principle was subsequently done from diethyl ether fraction. The diethyl ether fraction was separated into acidic and neutral part. The acid free fraction was screened to be positive in Brine Shrimp bioassay. The NMR spectra (in CDCl3) indicated the probability of its lipoidal nature. The total lipid fraction was resolved into neutral, glyco, and phospho-lipids by column chromatography. Only the neutral fraction sh...
Polyethylene pipes and connections are being widely used in treated water distribution services. Migration of low molecular weight compounds from the polyethylene into the water can change its final quality. This paper is about the concentrations and identification of the migration compounds found in treated water after staying in contact with low and high-density polyethylene. Identification and quantification were carried out using CLSA (Closed Loop Stripping Analysis) extraction technique and gas chromatography coupled to mass spectrometry (HRGC/HRMS). (Author) 12 refs.
Photodestruction has received much attention in recent years. In particular, titanium dioxide (TiO{sub 2}) and ozonolysis have attained a position of prominence. These technologies hold promise for the destruction of trace amounts of aqueous high explosives that are generated by load and pack operations, as well as demilitarization activities. Currently this water is treated by passing through a bed of activated carbon. The carbon is then steam regenerated and reused, thus creating a second waste stream which must be disposed of, or the carbon is burned directly. Recent trends in environmental regulation have shown that this may not be a viable option for process water remediation in the future. This talk will discuss efforts to employ alternate aqueous treatment techniques that not only remove the explosives compounds but are able to transform the parent compound into carbon dioxide and ...
In Situ Bioremediation (ISB) is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation. This process (ISB) involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove Volatile Organic Compounds (VOCs) from the vadose zone concomitant with biodegradation of the VOCs. This process is effective for remediation of soils and ground water contaminated with VOCs both above and below the water table. A full-scale demonstration of ISB was conducted as part of the Savannah River Integrated Demonstration: VOCs in Soils and Ground Water at Nonarid Sites. This demonstration was performed at the Savannah River Site from February 1992 to April 1993.
A field study (1993-96) assessed the benefits of applying unusually high rates of coal fly ash from power plants as a soil amendment to enhance water retention of soils without adversely affecting growth and marketability of the turf species, centipedegrass (Eremochloa ophiuroides (Munro) Hack.) A Latin Square plot design was employed that included 0 (control, no fly ash applied), 280, 560 and 1120 MgHa {sup -1} application rates of unweathered precipitator fly ash. The fly ash was spread evenly over each plot area, rototilled, and allowed to weather under natural conditions for 8 months before seeding. High levels of soluble salts, indicated by the electrical conductivity of soil extracts, in tandem with an apparent phytotoxic effect from boron, apparently inhibited initial plant establishment as shown by substantially lower germination counts in treated soil. However, plant height and rooting depth were not adversely affected, as were the dry ...
Ependymal cells line the cerebral ventricles forming the interface that separates the cerebrospinal (CSF) and interstitial fluids (ISF). Extracellular molecules move between ependymal cells, whereas lipid soluble molecules pass both between and through cells. We measured the transfer of tritiated water (TOH) from CSF to blood across the ependymal and capillary interfaces by ventriculocisternal (VC) steady-state tissue clearance. Adult cats anesthetized with pentobarbital sodium underwent VC perfusion with the extracellular marker (/sup 14/C)sucrose and TOH added to the artificial CSF. Brain tissue was analyzed for depth of penetration of the isotopes into periventricular gray matter. We found that TOH distribution space was lower than expected from water content measurements, whereas sucrose space was normal. Using VC steady-state equations we calculated an ependymal permeability that was similar to the permeability of the ...
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 [2009], Wiley Periodicals, Inc.)
Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex ...
Dynamics and metabolism of sugars translocated into the fruit region were investigated in tomato using {sup 14}C-labelled compounds. The translocation substance in tomato is thought to be sucrose, but the amount of sucrose in its fruit is very small. Therefore, the degradation of sucrose in the fruit and its translocation to the fruit was investigated. The sucrose was digested into hexoses such as glucose, fructose, etc. and the degradation rate was considerably low. In the stage of thickening growth, sucrose was more extensively converted into other substances except for sugars compared with the coloring stage. Then, {sup 14}C-labelled fructose was given through its gynophore to investigate the degree of reproduction to sucrose. The fructose level in the fruit reached the platean by 48 hrs after the addition and gradually decreased. The radioactivities were detected in sugars, organic acids and other alcohol soluble substances, etc. These ...
The kinetics of calcium sulfate crystal growth is of importance in various fields, such as geochemistry, desalination technology, petroleum industry, and water and wastewater treatment. The seeded crystal growth rate of calcium sulfate dihydrate was measured as a function of supersaturation in NaCl electrolyte solutions from 0 to 6 m at temperatures of 25, 50, 70, and 90 C. The growth followed a second-order parabolic rate law with activation energies greater than 53 kJ/mol which suggested the surface reaction as the rate-limiting step. It was observed that the rate constant and the activation energy are solution composition dependent. The rate constant increases with NaCl concentration up to 3 molal and then begins to fall slightly. The activation energy dropped from 61 kJ/mol in the pure Ca-SO[sub 4]H[sub 2]O system to 53 kJ/mol in 3.0 m NaCl solutions. The electrolyte effect was similar to the crystal solubility behavior in aqueous ...
The accumulation of osmolytes in leaf tissues and the abscisic acid-induced stomatal closure are well-recognized mechanisms associated with drought tolerance in crop plants. We determine the response in terms of osmotic potential and the contents of leaf proline, glycine betaine and soluble sugar at booting and grain filling stages of four wheat (Triticum aestivum L.) cultivars to drought and exogenously applied abscisic acid (ABA) in a pot study. Leaf sample were collected 3, 6 and 9 days after drought induction and at 48 and 72 h of re-watering (recovery). Marked decreases in osmotic potential associated with the accumulation of proline, glycine betaine and soluble sugars occurred under conditions of drought stress Accession 011320 was most sensitive to drought and showed the largest decrease in osmotic potential and least accumulation of proline, sugar and glycine betaine The inhibitory effects of drought stress were ...
The microstructures of so called high temperature alloys, which have been developed for service temperatures up to 800"0C, are not necessarily stable at higher temperatures. The mobility of alloying elements is very high in FeCrNi alloys at 950 "0C e.g. iron, chromium or nickel can diffuse up to 0.1 mm distance in one year, which is about a grain diameter. Interstitials like carbon or nitrogen show a four orders of magnitude higher diffusivity than the alloying elements. In addition, the carbon solubility in this type of alloy is reported to be very low. Therefore the alloys are supersaturated with carbon after heat treatment above 1100 "0C and water quenching although the absolute carbon content is very low. At service temperatures around 800"0C the solubility of carbon is still about one order of magnitude lower than at heat treatment temperature. This will lead, together with the high mobility of elements, to ...
Chlorination of water can lead to the formation of chloropicrin. The numerous potential precursors (of various reactivities) observed during this study, confirm this hypothesis. Combination of ozonation and chlorination can also lead to the formation of this compound, dangerous to health; however, the conditions of the formation and particularly the impact of a nitration reaction in the gas phase are still not clearly defined.
The authors studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiometic purity (e.p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35C. The enzyme exhibited maximum activity at a water content of 13 [plus minus] 2% (w/w). The enantiomeric purity obtained was 83 [plus minus] 2% of (S)-glycidol butyrate and did not depend on the alcohol concentration or the enzyme water ...
A new strontium metal-organic framework, [Sr2(BTEC)(H2O)4] 2H2O (1) (H4BTEC=benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437nm after dehydration.
Several lanthanide shift reagents (LSR) were synthesized from praseodymium, europium, dysprosium, and terbium using ethylenediaminetetraacetic acid, trans-1,2-diaminocyclohexane-N,N,N[prime],N[prime]-tetraacetic acid, and diethylenetriaminepentaacetic acid for the purpose of separating overlapping [sup 31]P FT-NMR spectral signals of dissolved organic phosphorus compounds present in concentrated lake-water samples. The extent of change in signal position and line width of several known phosphorus compounds dissolved in pure water was examined as a function of solution pH and the molar ratio of LSR to phosphorus. Praseodymium ethylenediaminetetraacetate (PrEDTA) was determined to be the most effective LSR. Concentrated lake-water samples mixed with PrEDTA were examined with [sup 31]P FT-NMR. The use of PrEDTA provided separation of overlapping signals, indicated that phosphorus ...
Several types of corrosion have damaged alloy 600 tubing in the secondary side of steam generators. The types of corrosion include wastage, denting, intergranular attack, stress corrosion, erosion-corrosion, etc. The environments which cause attack may originate from leaks of cooling water into the condensate, etc. When the contaminated feedwater is pumped into the generator, the impurities may concentrate first 200 to 400 fold in the bulk water, depending on the blowdown, and then further to saturation and dryness in heated tube support plate crevices. Characterization of local solution chemistries is the first step to predict and correct the type of corrosion that can occur. The pH is of particular importance because it is a major factor governing the rate of corrosion reactions. The pH of a solution at high temperature is not the same as the ambient temperature, since ionic dissociation constants, solubility and ...
In situ air stripping (ISAS) technology was developed to remediate soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISAS employs horizontal wells to inject (sparge) air into the ground water and vacuum extract VOCs from vadose zone soils. The innovation is creation of a system that combines two somewhat innovative technologies, air sparging and horizontal wells, with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.
In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.
Abstract The air-water interface presents several interesting features, namely a) a molecularly flat environment, b) a boundary region between two phases with different dielectric constants, c) permits or promotes dynamic interactions within the interface region, and d) a point of interaction between hydrophobic compounds and aqueous molecules. Accordingly, Langmuir monolayers at the air-water interface have several unique characteristics and properties, which require investigation. In this review-type personal account, typical examples of molecular recognition and molecular patterning at air-water interfaces are first introduced, followed by descriptions of specific and unusual properties of monolayers on water. In addition, two examples of our own results concerning Langmuir monolayers a...
Banana (Musa acuminata Colla AAA) peel extracts obtained in this work had a high capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2prime-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS+) free radicals, and they were also good lipid peroxidation inhibitors. Acetone:water extracts were considerably more effective (compared with methanol, ethanol, acetone, water, methanol:water or ethanol:water) at inhibiting the peroxidation of lipids in the b-carotene/linoleic acid system or scavenging free radicals. However, aqueous extracts had a high capacity to protect lipids from oxidation in the thiobarbituric acid reactive substances (TBARS) test, as well as in the b-carotene bleaching assay. In addition, acetone:water most efficiently extracted all extractable components (54+-...
In order to design catalysts suitable for primary liquefaction stage and secondary upgrading stage respectively in the multi-stage liquefaction process, various carbon-supported catalysts were prepared. Catalytic activities of them were investigated for the hydrogenation of 1-methylnaphthalene, to discuss the influences of metals and carbon species on the catalytic activity. Various watersoluble and oil soluble Mo and Ni salts were used for NiMo supported catalysts. Among various carbon supports, Ketjen Black (KB) was effective for preparing the catalyst showing the most excellent hydrogenation activity. The KB and Black Pearl 2000 (BP2000) showing high hydrogenation activity were fine particles having high specific surface area more than 1000 m{sup 2}/g and primary particle diameter around 30 nm. This was inferred to contribute to the high dispersion support of active metals. Since such fine particles of carbon exhibited ...
Exchange of hardness ions is important in enhanced oil recovery with chemical additives. In both micellar-polymer and caustic flooding processes, multivalent ions released from rock surfaces can interact with anionic surfactants, rendering them preferentially oil soluble and/or insoluble in water. Because hardness cations are sparingly soluble and precipitate in alkaline solutions, such solutions may be more efficient as surfactant flood preflushes than are softened brines. Multivalent ion precipitation may also occur in alkaline waterflooding. To permit design of such processes, this paper presents a chromatographic theory for simultaneous ion exchange with precipitation of divalent ions. Theoretical effluent histories and concentration profiles are presented for the cases of finite pulses and continuous injection of hydroxide ions into linear cores. Complete capture of the insoluble salt particles is assumed. Results are ...
Phase relations in the ternary system Ce-Pd-Si have been established for the isothermal section at 800 deg. C based on X-ray powder diffraction and EMPA techniques on about 130 alloys, which were prepared by arc-melting under argon or powder reaction sintering. Eighteen ternary compounds have been observed to participate in the phase equilibria at 800 deg. C. Atom order was determined by direct methods from X-ray single-crystal counter data for the crystal structures of #tau#_8-Ce_3Pd_4Si_4 (U_3Ni_4Si_4-type, Immm; a=0.41618(1), b=0.42640(1), c=2.45744(7) nm), #tau#_1_6-Ce_2Pd_1_4Si (own structure type, P4/nmm; a=0.88832(2), c=0.69600(2) nm) and also for #tau#_1_8-CePd_1_-_xSi_x (x=0.07; FeB-type, Pnma; a=0.74422(5), b=0.45548(3), c=0.58569(4) nm). Rietveld refinements established the atom arrangement in the structures of #tau#_5-Ce_3PdSi_3 (Ba_3Al_2Ge_2-type, Immm; a=0.41207(1), b=0.43026(1), c=1.84069(4) nm) and #tau#_1_3-Ce_3_-_xPd_2_0_+_xSi_6 ...
Removal of sulfonamide (SAs) and tetracycline (TAs) classes of antibiotic compound from deionized water and DOC water by powdered activated carbon (PAC) adsorption was evaluated in this study. According to the study results, TAs were more easily adsorbed than SAs although TAs were more hydrophilic than SAs. The phenolic compounds in TAs might be responsible for their high adsorption. Complex formation of TAs with metal and metal oxide on the surface of activated carbon might also contribute to higher adsorption. The hydrophobic effect was important for removal of SAs. More hydrophobic SAs were removed more easily. The carbon type was not important for adsorption of SAs and TAs. Coal based carbon and coconut based carbon showed similar removal efficiencies for these antibiotics. Dissolved organic materials interfered with adsorption of SAs and TAs. Organic interference was more significant for the ...
The presence of soluble sulfide in produced water results in problems for the petroleum industry due to its toxicity, odor, corrosive nature, and potential for wellbore plugging. Sulfide oxidation by indigenous nitrate-reducing bacteria (NRB) present in brine collected from wells at the Coleville Unit (CVU) in Saskatchewan, Canada, was investigated. Sulfide oxidation took place readily when nitrate and phosphate were added to brine enrichment cultures, resulting in a decrease in sulfide levels of 99-165 ppm to nondetectable levels (< 3.3 ppm). Produced water collected from a number of producing wells was screened to determine the time required for complete sulfide oxidation, in order to select candidate wells for treatment. Three wells were chosen, based on sulfide removal in 48 hours or less. These wells were treated down the backside of the annulus with a solution containing 10 mM KNO{sub 3} and 100 {mu}M NaH{sub ...
In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target ...
In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target ...
Because of the environmental hazard of organic solvents such as chlorinated or aromatic hydrocarbons, watersoluble and biodegradable substitutes have come into use. It should be assessed how they affect soil and aquifer when spilled in leaks or accidents. This was simulated in a model system using methanol and percolation columns, one filled with material from the unsaturated subsurface and two with different materials from aquifers. The results reveal that a spill of the substitutes can also cause problems. In homogeneous soils and at long retention times until the substance reaches the aquifer, sorption and biological degradation are most likely to prevent contamination of the groundwater. When oxygen supply in the subsurface is insufficient, reducing conditions occur and sulphide is formed. The data show that much more methanol was eliminated than reflected by the consumption of electron acceptors. This indicates that sorption and anabolic ...
A new process for the removal of tar from biosyngas, OLGA (Oil and Gas Washer), is presented. This gas cleaning technology is based on physical principles and is designed to eliminate tar problems that relate to fouling and er pollution. The applied principles are confirmed by experimental validation. OLGA can be operated without suffering from harmful effects on important gasification characteristics as cold gas efficiency, gasifier simplicity, and feedstock flexibility. Some fundamental considerations in the development of OLGA are discussed. Amongst these is a different approach to the tar problem. This approach does not consider the total tar content as decisive in the evaluation of gas cleaning equipment. Instead, evaluation is focussed on whether tar properties as condensation behaviour and watersolubility can still occur. A biosyngas free of tar should therefore be synonymous to a biosyngas that is free of tar related problems.
Upon addition of permanganate to a solution of tryptophan (Trp), yellow-brown color species appears within the time of mixing of tryptophan in absence and presence of cetyltrimethylammonium bromide (CTAB), which was stable for some days. Spectroscopic and kinetic evidences suggest the formation of water-soluble colloidal MnO2 as the most stable reduction product of MnO4-. Carbon dioxide and ammonia are not formed as the oxidation products. Carbon-carbon double bond of indole moiety of Trp is responsible for the fast reduction of permanganate. Cetyltrimethylammonium bromide catalyses the permanganate oxidation of Trp with a rate enhancement of ca. 200-fold. Sub- and postmicellar catalytic effect of CTAB ascribed to the association/incorporation/solubilization of both reactants (MnO4- and Tr...
Fourier-transform infrared (FTIR) spectroscopy was used to monitor amino acids, organic acids, and changes during ripening. Twelve Cheddar cheese samples were ripened for 73 days and samples were drawn periodically. Water-soluble fractions of samples were analyzed by gas chromatography (20 amino acids), liquid chromatography (three organic acids), and FTIR spectroscopy (4000-700 cm-1). Spectra were correlated with chromatographic data and ripening events and analyzed by multivariate statistics to develop prediction and classification models. Most models showed a good fit (correlation coefficient > or =0.89) and could predict the levels of amino acids and organic acids and age of the cheese in less than 20 min. Lactic acid, leucine, glutamic acid, asparagine, phenylalanine, and valine were ...
Purpose: To compare the diagnostic quality and adverse events of the water-soluble, non-ionic, iso-osmolar, dimeric contrast media iodixanol and iotrolan in hysterosalpingography (HSG). Material and Methods: One hundred and twenty patients participated in a double-blind randomized parallel-group phase-III study. Questionnaires and patient interviews were used. Diagnostic quality was assessed using a visual analogue scale and the quality in specific regions was rated using a categorical scale. Results: Overall diagnostic quality was equal for the two groups. There was no statistically significant difference between the two groups in diagnostic quality in the specific regions of interest. No differences between the contrast media were found with regard to adverse events. Conclusion: Both contrast media provided images of high diagnostic quality in HSG. (orig.)
Biotin is an essential water-soluble vitamin crucial for maintaining normal body functions. The importance of biotin for human health has been under-appreciated but there is plenty of opportunity for future research with great importance for human health. Currently, carrying out predictions of biotin metabolism involves tedious manual manipulations. In this paper, we report the development of BiotinNet, an internet based program that uses Bayesian networks to integrate published data on various aspects of biotin metabolism. Users can provide a combination of values on the levels of biotin related metabolites to obtain the predictions on other metabolites that are not specified. As an inherent feature of Bayesian networks, the uncertainty of the prediction is also quantified and reported to...
Changes in soil properties and vegetable growth were quantified on a low-fertility tropical soil. Four treatments (two composts, urea, and control) were applied to an Oxisol (Rhodic Haplustox, Wahiawa series) in a field on Oahu, Hawaii. Chinese cabbage (Brassica rapa, Chinensis group) and eggplant (Solanum melongena) were grown sequentially as test crops. Soil quality as measured by hot-water-soluble carbon, dehydrogenase activity, and cation exchange capacity (CEC) increased by compost amendments. Total organic carbon or carbon dioxide (CO2) respiration rate did not correlate with the soil amendments. Nitrogen (N) nutrition was the main factor that improved growth and carotenoid content in cabbage. The urea treatment promoted better growth in cabbage, whereas good-quality compost, made of...
Summary Background The incidence of food allergy to wheat is increasing. Its diagnosis depends on the purity of major allergens and their inclusion in tests. Isolation and characterization of wheat allergens are therefore of utmost importance. Objective To purify and identify wheat flour allergens most frequently recognized by patients' IgE antibodies and to study their allergenicity. Methods Water/salt-soluble extracts from wheat flour were prepared and separated using a combination of ultrafiltration, isoelectric focusing and liquid chromatography. Purified proteins were analysed by immunoblotting using pooled sera from patients with atopic dermatitis who possessed IgE specific to wheat. Wheat proteins found to bind IgE were subsequently identified by matrix-assisted laser desorption/ion...
Microbial degradation of aromatic hydrocarbons has been studied with the aim of developing applications for the removal of toxic compounds. Efforts have been directed toward the genetic manipulation of mesophilic bacteria to improve their ability to degrade pollutants, even though many pollution problems occur in sea waters and in effluents of industrial processes which are characterized by low temperatures. From these considerations the idea of engineering a psychrophilic microorganism for the oxidation of aromatic compounds was developed.In a previous paper it was demonstrated that the recombinant Antarctic Pseudoalteromonas haloplanktis TAC125 (PhTAC/tou) expressing a toluene-o-xylene monooxygenase (ToMO) is able to convert several aromatic compounds into corresponding catechols. In our work we improved the metabolic capability of PhTAC/tou cells by combining action of recombinant ToMO enzyme with ...
Experiments on aqueous TiO{sup 2} photocatalytic reaction characteristics of 4 nitrogen-containing and 12 aromatic organic compounds were carried out. Based on the values calculated for the distribution of ionic species and atomic charge, the characteristics of their photocatalytic decomposition were estimated. It was shown that the dependence of decomposition of the N-containing compounds were linearly proportional to their nitrogen atomic charge values, while that of the aromatic compounds were inversely proportional. The effects of aqueous pH, oxygen content and concentration on the TiO{sup 2} photocatalytic characteristics of EDTA-Cu(II) and EDTA-Fe(III) were experimentally investigated. All EDTA systems were decomposed better in the pH range of 2.5{approx}3.0 and with more dissolved oxygen. These results could be applied to a unit process for removal of organic impurities dissolved in a source ...
Numerous studies have investigated degradation of individual endocrine disrupting compounds (EDCs) in lab or natural waters. However, natural variations in water matrices and mixtures of EDCs in the environment may confound analysis of the treatment efficiency. Because chemical based analytical methods cannot represent the combined or synergistic activities between water quality parameters and/or the EDC mixtures at environmentally relevant concentrations ({mu}g L{sup -1}-ng L{sup -1}), bioanalytical assessments of residual estrogenic activity in treated water were used to evaluate the performance of the UV based advanced oxidation process for estrogenic contaminants in water. Four EDCs including estradiol (E{sub 2}), ethinyl estradiol (EE{sub 2}), bisphenol-A (BPA) and nonylphenol (NP) were spiked individually or as a mixture at {mu}g L{sup -1}-ng L{sup -1} in ...
Most waste water treatment plants have processes to remove nutrients in order to avoid eutrophication in water receiving bodies. Regarding phosphorus removal. the most common option is chemical precipitation with ferric or aluminical precipitation with ferric or aluminium salts. We show here the successful experience carried out by the WWTP of Blanes and the company Safloc. A method ato remove phosphorus from waste water was developed by adding sodium aluminate. The use of this compound has turned out to be a sustainable way for this purpose in terms of costs, reliability and minimization of sludge production. (Author)
Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified #beta#-amino acid that was identified as N"v"a"r"-"e"p"s"i"l"o"n-acetyl-#beta#-lysine by NMR spectroscopy and ion-exchange HPLC. This #beta#-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine ...
The electrochemical behavior of some zirconium alloys including Zry-2 with various #SIGMA#Ai from 2.5 x 10"-"2"0 to 1.2 x 10"-"1"7 (h), modified Zry-2 with iron contents of 0.15, 0.25, and 0.5%, and standard Zry-4 was studied by measuring anodic polarization curves in sulfuric acid solution. The results of these electrochemical tests were compared with those of steam autoclave tests. In Zry-2, the current peak was observed at 1250 mV (versus SCE) on the anodic polarization curve, and this peak area increased with #SIGMA#Ai and with the size of secondary precipitates. Also, this peak was closely correlated with nodular corrosion resistance as expected from the above results. As iron contents in modified Zry-2 increased, the current peak at 1,250 mV decreased and a new peak at 1,900 mV appeared. The former peak disappeared and the latter peak increased further at 0.5% iron. In Zry-4, the current peak was observed at 1,900 mV, but not at 1,250 mV, and this behavior was the same as that of ...
Chinese brake fern (Pteris vittata L.), an arsenic (As) hyperaccumulator, has shown the potential to remediate As-contaminated soils. This study investigated the effects of soil amendments on the leachability of As from soils and As uptake by Chinese brake fern. The ferns were grown for 12 weeks in a chromated-copper-arsenate (CCA) contaminated soil or in As spiked contaminated (ASC) soil. Soils were treated with phosphate rock, municipal solid waste, or biosolid compost. Phosphate amendments significantly enhanced plant As uptake from the two tested soils with frond As concentrations increasing up to 265% relative to the control. After 12 weeks, plants grown in phosphate-amended soil removed >8% of soil As. Replacement of As by P from the soil binding sites was responsible for the enhanced mobility of As and subsequent increased plant uptake. Compost additions facilitated As uptake from the CCA soil, but decreased As uptake from the ASC soil. Elevated As uptake in the ...
A membrane process utilizing dialysis and selective complexation by water-soluble polymers has been developed. This process, termed affinity dialysis, has been shown to be selectively extract and concentrate both cations and anions in a manner similar to ion exchange or solvent extraction. The selective removal of calcium from sodium with selectivity of about 30, removal of chromate ion from dilute streams, and separation of transition metal ions such as Cu/Fe and Cu/Zn have all been successfully demonstrated. Effects of different polymers, polymer concentration, temperature, and flow rates have been studied. The effect of increased polymer concentration is to increase product concentration if appropriate changes in feed, polymer solution, and strip flow rates are made. A continuous polymer solution recycle and regeneration system has been constructed and operated with Cu/Zn and chromate/chloride feed streams. Removal of over 95% of the desired ion in one pass and ...
Oxyanions of uranium, selenium, chromium, arsenic, technetium, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites, and in other areas of the U.S.. A potential remediation method is to react the contaminated water with zero-valent iron (ZVI). We are performing fundamental investigations of the interactions of the relevant compounds with Fe filings and single- and poly-crystalline surfaces. The aim of this work is to develop the physical and chemical understanding that is necessary for the development of cleanup techniques and procedures.
Improvement in efficiency and profitability of hydrogenation reaction of heavy hydrocarbon resources is the most important matter to be done. In this study, coprocessing of coal and heavy oil vacuum residue was conducted using syngas-water as a hydrogen source. For the investigation of effect of the reaction temperature during the coprocessing of Wandoan coal and Arabian heavy vacuum residue using Fe(CO)5 as a catalyst, the conversion, 66.0% was obtained at 425{degree}C. For the investigation of effect of reaction time, the yield of light fractions further increased during the two stage reaction at 400{degree}C for 60 minutes and at 425{degree}C for 60 minutes. Finally, almost 100% of THF-soluble matter was obtained through the reaction using 2 mmol of Fe(CO)5 catalyst at 400{degree}C for 60 minutes, and hydrogenation of heavy oil was proceeded simultaneously. When comparing coprocessing reactions using three kinds of hydrogen sources, i.e., ...
New palladium(II) complexes (2), bearing NHC/TPPTS ligands, (NHC=benzimidazol-2-ylidene; TPPTS=triphenylphosphine-3,3',3''-trisulfonic acid trisodium salt) have been prepared and characterized by elemental analyses and spectroscopic methods. Their ability to catalyze the Suzuki-Miyaura reaction in neat water has been studied at 100^oC. Very high activities have been observed in the coupling of phenylboronic acid with aryl chlorides in the presence of 1% of the catalyst. We have compared the electronic properties of cis-[PdBr2(NHC)(TPPTS)] with the related complexes, [PdX2(NHC)]2 and [trans-PdBr2(NHC)(pdca)] (pdca=pyridine-2,6-dicarboxyic acid) (3) via three different techniques: cyclic voltammetry, thermogravimetric analysis and ^1^3C NMR spectroscopy.
The reaction of the retinylidene Schiff base in bacteriorhodopsin (bR) to the water-soluble reagent hydroxylamine is enhanced by greater than 2 orders of magnitude under illumination. We have used this reaction as a probe for changes in Schiff base reactivity during the photocycle of wild-type bR and mutants defective in proton transport. We report here that under illumination at pH 6, the D85N mutant has a 20-fold lower rate and the D212N mutant has a greater than 4-fold higher rate for the light-dependent reaction with hydroxylamine compared with wild-type bR. In contrast, the reactivities of wild-type bR and the D96N and T46V mutants are similar. It has been previously shown that the D96N and T46V replacements have no significant effect on the kinetics of M formation but have dramatic effects on rate of the decay of M. We therefore conclude that the hydroxylamine reaction occurs before formation of the M intermediate. Most likely it occurs at the L stage of the ...
This is the annual report of the Radiological and Environmental Division of the Argonne National Laboratory for 1982. Studies of the effects of ozone on crop growth and yield have been carried out by the Terrestrial Ecology Group for winter wheat and for sorghum. The Microcosms for Acid Rain Studies (MARS) facility was completed in the early summer. Controlled investigations of plant and soil responses in acid rain were initiated with crop plants grown in two different midwestern soil types. The Transuranics Group has found that the solubility and adsorptive behavior of plutonium previously observed at fallout concentrations in natural waters (approx. 10/sup -16/ to 10/sup -18/ M) is applicable at plutonium concentrations as high as 10/sup -8/ M. The Lake Michigan eutrophication model has been adapted to operation in a Monte Carlo mode. Simulations based on yearly phosphorus loadings and winter conditions were selected at random from prescribed ...
A workshop on radioactivity in coal use was held on September 15 through 17, 1981, under the auspices of the US Department of Energy, Office of Environmental Programs, and the Los Alamos National Laboratory. The purpose of the workshop was to identify research issues associated with radioactivity resulting from the use of coal for electric power generation. The concensus of the 10 scientists participating in the workshop was that a moderate to strong need exists for research in solubility of fly ash in different fluids and for determination of radioactivity in construction materials. Several additional research issues were identified but were given a lower priority. Summaries of each presentation are included. Titles are: some effects of coal combustion on the radiation environment; radionuclides in western coal at Mound; low-level radiation in coals utilized and ashes produced at New York State electric utilities; radioactivity from coal use - where are the ...
Acid Rock Drainage (ARD) is the product formed by the atmospheric oxidation of the relatively common pyrite and pyrrhotite. Waste rock dumps and tailings containing sulfide mineral have been reported at toxic materials producing ARD. Mining in sulphide bearing rock is one of activity which may lead to generation and release of ARD. ARD has had some major detrimental affects on mining areas. The purpose of this study was carried out to develop disposal method for preventing contamination of water and soil environment by waste rocks dump and tailings, which could discharge the acid drainage with high level of metals. Scope of this study was as following: environmental impacts by mine wastes, geochemical characteristics such as metal speciation, acid potential and paste pH of mine wastes, interpretation of occurrence of ARD underneath tailings impoundment, analysis of slope stability of tailings dam etc. The following procedures were used as part of ARD evaluation and ...
Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. This paper describes the roles on corrosion. A corrosion test on precipitate-containing and precipitate-free materials made from pure zirconium and a small quantity of iron and chromium, rest potential measurements on an intermetallic compound of Zr(FeCr){sub 2} and zirconium matrix, and a galvanic coupling test of those were performed. Results showed that corrosion behavior of zirconium alloys could be attributed to the electrochemical properties of intermetallic compounds precipitated in each alloy. Namely, the cathodic and anodic polarization characteristics were associated with anodic protection provided by the precipitates on the alloys and the precipitates degradation in ...
Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. This paper describes the roles on corrosion. A corrosion test on precipitate-containing and precipitate-free materials made from pure zirconium and a small quantity of iron and chromium, rest potential measurements on an intermetallic compound of Zr(FeCr)_2 and zirconium matrix, and a galvanic coupling test of those were performed. Results showed that corrosion behavior of zirconium alloys could be attributed to the electrochemical properties of intermetallic compounds precipitated in each alloy. Namely, the cathodic and anodic polarization characteristics were associated with anodic protection provided by the precipitates on the alloys and the precipitates degradation in the ...
This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and ground water. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation.
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.
The use of filters of activated-charcoal particles in drinking-water purification plants assists in the elimination of organic micropollutant substances. The authors report on a study which sought to investigate the mechanism of organic matter; they describe the experimental programme, which used different size ranges of mineral-based activated charcoal, present the experimental findings and discuss the results. 16 references.
The structure of a fragment of the germanium complex compound (GCC) with oxyethylidenediphosphonic acid and the adsorption properties of GCC films with respect to the vapors of water and some other organic liquids have been studied. The electric conductivity of GCC films has been investigated, and its mechanism has been explained.
Apoptosis and Proliferation During DicWoroacetic Acid (DCA) Induced Hepatocellular Carcinogenesis in the F344 Male Rat Chlorine, introduced into public drinking \\\\'ater supplies for disinfection, can react with organic compounds in surface waters to form toxic by-prod...
Experiments were performed to measure the transfer of trichloroethylene (TCE), a volatile organic compound (VOC), from tap water in showers to indoor air. In these experiments, the loss of TCE from tap water in the shower is based on the difference between influent and effluent concentrations.We have developed and previously published a three-compartment model, which we use to simulate the 24-h concentration history of VOCs in the shower, bathroom, and remaining household volumes resulting from the use of contaminated tap water. An important input to this model is the transfer efficiency of the VOC from water to air. The experiments reveal that the transfer efficiency of TCE from shower water to air has an arithmetic mean value of 51 percent and an arithmetic standard deviation of 9 percent. Analysis of the results shows that there is no statistically ...
The activated charcoal treatment in the field of the water treatment is applied to water supply, sewage, industrial water supply and industrial sewage, etc.. Its main treatment effects are (1) decolorization, (2) removal of odorous substance, (3) removal of organic material which is detected as COD or BOD, (4) removal of harmful substance, (5) removal of substance which could generate muddness and tarnish and (6) removal of organic material which affects the succeeding high degree treatment badly, etc.. Many actual application examples in the above fields have been reported. As the most recent topic, a big amount of the demand of activated charcoal is expected in the treatment of water supply. Chlorine which is used as disinfectant during the water purification process generates organic halogen compounds such as trihalomethane through the reaction with precursor ...
The steroidogenic factor 1 (SF-1, also known as NR5A1) is a transcription factor belonging to the nuclear receptor superfamily. Whereas most of the members of this family have been extensively characterized, the therapeutic potential and pharmacology of SF-1 still remains elusive. Described here is the identification and characterization of selective inhibitory chemical probes of SF-1 by a rational ultra-high-throughput screening (uHTS) strategy. A set of 64,908 compounds from the National Institute of Health's Molecular Libraries Small Molecule Repository was screened in a transactivation cell-based assay employing a chimeric SF-1 construct. Two analogous isoquinolinones, ethyl 2-[2-[2-(2,3-dihydro-1,4-benzodioxin-7-ylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate (SID7969543) and ethyl 2-[2-[2-(1,3-benzodioxol-5-ylmethylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate and (SID7970631), were identified as potent submicromolar inhibitors, yielding ...
The reaction of uranium oxides and chlorine to prepare anhydrous uranium tetrachloride (UCl{sub 4}) are important to more economical preparation of uranium metal. The most practical reactions require carbon or carbon monoxide (CO) to give CO or carbon dioxide (CO{sub 2}) as waste gases. The chemistry of U-O-Cl compounds is very complex with valances of 3, 4, 5, and 6 and with stable oxychlorides. Literature was reviewed to collect thermochemical data, phase equilibrium information, and results of experimental studies. Calculations using thermodynamic data can identify the probable reactions, but the results are uncertain. All the U-O-Cl compounds have large free energies of formation and the calculations give uncertain small differences of large numbers. The phase diagram for UCl{sub 4}-UO{sub 2} shows a reaction to form uranium oxychloride (UOCl{sub 2}) that has a good solubility in molten UCl{sub 4}. This appears more ...
Field experiments were conducted on the sulphur-deficient Typic Haplustepts of the IARI farm for two consecutive, kharif seasons viz. 1996 and 1997 with soybean cultivar Pusa 22 as the crop. Varying rates of S as gypsum were basally applied in the main plots adjacent to the micro plots (1 m x 1 m) to quantify the partitioning of the fertilizer-sulphur taken up by soybean and its distribution in the soil profile. Soybean responded to the application of sulphur, with increase in yield being obtained up to rate of 40 kg S ha"-"1. Data computed on distribution of the S derived from labelled gypsum and percent S utilization by the soybean crop increased from 13.23 and 4.15 to 23.41 and 6.39, respectively. During 1996, the per cent utilization of labelled S ranged from 5.6 to 8.8. Monitoring of added sulphur in the soil profile up to a depth of 1 m revealed maximum accumulation of the added S in 30-60 cm soil layer. With the help of "3"5S around 11 to 18 per cent of the added S was traced in ...
An important advantage of carrying out enzymatic catalysis in organic media is the increased solubility of hydrophobic substrates. This study compares a model lipase catalyzed esterification of cholesterol using vinyl acetate (VA) in two such nontraditional media: high-pressure hexane and supercritical (SCF) ethane. The effect of using one of the reactants (VA) as a cosolvent to increase the solubility of the other reactant (cholesterol) in SCF ethane has been investigated. The thermodynamic activity of water (a(w)) in the reaction media was controlled by the direct addition of the salt hydrate pair Na(4)P(2)O(7)/Na(4)P(2)O(7).10H(2)O. The a(w) of the salt hydrate system is shown to be a function of pressure and its variation over the pressure range 104-173 bar has been estimated. The initial reaction rate in pressurized hexane was found to vary linearly with the cholesterol concentration. The reaction rate was also a ...
Samples of two seawater farmed fish (crimson snapper (Lutjanus erythopterus) and snubnose pompano (Trachinotus blochii)), water, air, sediment, fish feed, macroalgae and phytoplankton were collected from two estuarine bays (Daya Bay and Hailing Bay) in South China. The concentrations of persistent halogenated compounds (PHCs) including polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and polychlorinated biphenyls (PCBs) varied widely with the different sample matrices under investigation. The compositional patterns in fish, fish feed, macroalgae and phytoplankton, as well as the good correlations between the abundances of p,pprime-DDT and BDE-209 and their metabolites (i.e., p,pprime-DDD and p,pprime-DDE for p,pprime-DDT and BDE-47 for BDE-209) in fish indicated the occurr...
This patent describes a method of improving the S0{sub 2} scrubbing efficiency of flue gas desulfurization scrubbers. It comprises conducting the scrubbing operation in such scrubbers in the presence of an oil-soluble surfactant.
SummarySoluble epoxide hydrolase (sEH) is a key enzyme in the metabolic conversion and degradation of P450 eicosanoids called epoxyeicosatrienoic acids (EETs). Genetic variations...Full Text Available
The soluble subcellular fraction of a chlB mutant contains an inactive precursor form of the molybdoenzyme nitrate reductase, which can be activated by the addition to the soluble fraction of protein...Full Text Available
We compared two insecticidal and eight noninsecticidal soil isolates of Bacillus thuringiensis with regard to the solubility of their proteinaceous crystals at alkaline pH values. The...Full Text Available
Realization of Pharmacological Tests, Development of the Specifications and Technical Documentation and Registration in the Russian Federation of Medical Products as Soluble Tablets of Acetylsalicylic Acid/Calcium Carbonate in Two Dosages Intended for use as Medical Products Smoothing, Febrifugal and Antiaggregation Action and Development of Technology of Tableting the Above-Stated Preparations
The corrosion behaviour of the stainless steels 304, 316 Ti, 25Cr-20Ni-Mo-Ti, nickel base alloys Hastelloy C4, Inconel 625, Incoloy 800, Ti and Ti-0.2% Pd alloy has been studied in the aerated or deaerated solutions at 20/sup 0/C and 90/sup 0/C whose compositions are representative of interstitial ground waters: granitic or clay waters or salt brine. The electrochemical techniques used are voltametry, polarization resistance and complexe impedance measurements. Electrochemical data show the respective influence of the parameters such as temperature, solution composition and dissolved oxygen, addition of soluble species chloride, fluoride, sulfide and carbonates, on which depend the corrosion current density, the passivation and the pitting potential. The inhibition efficiency of carbonate and bicarbonate activities against pitting corrosion is determined. In clay water at 90/sup 0/C, Ti and Ti-Pd show ...
Phase relations in the ternary system Ce-Pd-Si have been established for the isothermal section at 800 deg. C based on X-ray powder diffraction and EMPA techniques on about 130 alloys, which were prepared by arc-melting under argon or powder reaction sintering. Eighteen ternary compounds have been observed to participate in the phase equilibria at 800 deg. C. Atom order was determined by direct methods from X-ray single-crystal counter data for the crystal structures of tau{sub 8}-Ce{sub 3}Pd{sub 4}Si{sub 4} (U{sub 3}Ni{sub 4}Si{sub 4}-type, Immm; a=0.41618(1), b=0.42640(1), c=2.45744(7) nm), tau{sub 16}-Ce{sub 2}Pd{sub 14}Si (own structure type, P4/nmm; a=0.88832(2), c=0.69600(2) nm) and also for tau{sub 18}-CePd{sub 1-x}Si{sub x} (x=0.07; FeB-type, Pnma; a=0.74422(5), b=0.45548(3), c=0.58569(4) nm). Rietveld refinements established the atom arrangement in the structures of tau{sub 5}-Ce{sub 3}PdSi{sub 3} (Ba{sub 3}Al{sub 2}Ge{sub 2}-type, Immm; a=0.41207(1), ...
In the framework of the search for a ceramic material usable in the radioactive waste storage, uranium and thorium phosphates have been investigated. Their experimental synthesis conditions have been entirely reviewed, they lead to the preparation of four new compounds: U(UO{sub 2})(PO{sub 4}){sub 2}, U{sub 2}O(PO{sub 4}){sub 2}, UCIPO{sub 4}, 4H{sub 2}O, and Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}. Experimental evidenced are advanced for non existent compounds such as: U{sub 3}(PO{sub 4}){sub 4}, U{sub 2}O{sub 3}P{sub 2}O{sub 7} and Th{sub 3} (PO{sub 4}){sub 4}. Characterization by several techniques (X-rays and neutron powder diffractions, UV-Visible and Infra-red spectroscopies, XPS,...) were performed. The ab initio structure determination of U(UO{sub 2})(PO{sub 4}){sub 2} has been achieved by X-rays and refined by neutron diffractions. Through its physico-chemical analysis, we found that this compound was a new ...
Findings indicate an urgent need to establish a monitoring program for persistent organic pollutants in water and sediment. - Marine culture is thriving in China and represents a major component of the regional economy in coastal zones, yet the environmental quality of many of those areas has never been studied. This paper attempts to investigate the quality status of Daya Bay, a key aquaculture area in China. The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in water and sediment samples of the bay. The total concentrations of 16 PAHs varied from 4228 to 29325 ng l"-"1 in water, and from 115 to 1134 ng g"-"1 dry weight in sediments. In comparison to many other marine systems studied, the PAH levels in Daya Bay waters were relatively high, and at six sites they were sufficiently high (>10 #mu#g l"-"1) to cause acute toxicity. The PAH composition pattern in sediments suggest ...
In our previous theoretical analyses, solubility-limited mass transfer from waste solids applies if a species is at a constant elemental concentration in liquid at the waste surface. For an element with isotopes that decay appreciably during the time of interest, a solubility boundary condition results in a time-dependent boundary concentration of each isotope. Here we present mass-transfer equations that include the effects of isotopic decay boundary conditions. 9 refs., 1 fig.
This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions ...
This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the ...
Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (#approx#900, 200 and 500 mg kg"-"1, respectively). Compost mulch increased organic carbon and Fe in soil pore water, which in turn increased As and Sb mobilization; this enhanced uptake by lettuce and sunflower. A very small proportion of the total soil trace element pool was in readily-exchangeable form (<0.01% As, <0.001% other trace elements), but the effect of compost on behaviour of metals was variable and ambiguous. It is concluded that greenwaste compost should be applied with caution to ...
Germination inhibition of the marine macrophyte Phyllospora comosa was utilized as a sub-lethal end-point to assess and compare the effects of four oil dispersants and dispersed diesel fuel and crude oil combinations. Inhibition of germination by the water-soluble fraction of diesel fuel increased following the addition of each of the dispersants; the nominal 48-h EC{sub 50} concentration of diesel fuel declined from 6800 to approximately 400 {mu}l 1{sup -1} nominal for each dispersed combination. This contrasted with crude oil, where the addition of two dispersants resulted in an enhanced germination rate and an increase in nominal EC{sub 50} concentrations from 130 {mu}l 1{sup -1} for the undispersed crude to 4000 and 2500 {mu}l 1{sup -1}. The results indicate that, while germination inhibition of P. comosa may be enhanced by the chemical dispersal of oil response varies with type of both oil and oil dispersant. (author)
This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key plutonium complexes. ...
Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to intake with an ...
The ruthenium decontamination factor in Purex process falls quickly with recycles of TBP. So it is necessary to change the chemical states of RuNO complexes in order to improve DF_R_u in the uranium purification cycle. The retention of RuNO complexes in TBP-kerosenelaurohydroxamic acid is observed to be quite large in our previous work. Therefore, water-soluble short chain hydroxamic acid is used as complexing agent to decrease the distribution coefficient of Ru. Hydroxamic acid can transform RuNO complexes into in-extractable species by TBP-kerosene in certain conditions. The result of cascade experiment indicates that the ruthenium decontamination can be increased by a factor of 40-50. Acidity has more influence on the effect of pretreatment. The higher acidity is, the worse the effect will be. The pretreatment is first carried out in low acidic solution, then extractive acidity is increased. In this way, the distribution of Ru can be decreased obviously. After ...
Magnetic particles have become very promising materials for drug delivery. However, preparation of magnetite particles with high surface area, biocompatibility, strong magnetic response, and suitable particle size still remains a major challenge. In this report, magnetite nanocrystal clusters with high surface areas were fabricated through a solvothermal process by introducing ammonium acetate as a porogen and trisodium citrate as a surface modification agent. The porosity, which was controlled by the reactant concentration, has been investigated in detail. The surface area of the nanocrystal clusters was as high as 141?m(2) g(-1) . Ibuprofen, as a model drug, was entrapped into the magnetite carriers. The interfacial interaction between the carboxylic groups on the drug molecules and the carboxylate groups on the carriers enhanced the loading efficiency. Low cytotoxicity in MCF-7 cell and in vitro constant drug release behavior combined with the high drug loading efficiency and high ...
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 ...
The effect of butylated hydroxytoluene (BHT) pretreatment (0.5% in the diet for 10 days) on the excretion, tissue distribution and DNA binding of orally administered (/sup 14/C)aflatoxin B1 (AFB1) was determined in male Fischer F344 rats. The amount of radioactivity excreted in the urine and feces by 24 hr was higher in BHT-treated rats than in controls. Treatment with BHT enhanced the excretion of water-soluble metabolites in the urine and in the large intestines plus feces at the earlier sampling times. The amount of radioactivity bound to hepatic nuclear DNA was six times less in the BHT-pretreated rats than in controls 6 hr after administration of the isotope. The half-lives of (/sup 14/C)DNA in the rat liver were 30 and 46 hr for control and BHT-pretreated rats, respectively. These results indicate that BHT pretreatment may protect the animal from the carcinogenic effects of AFB1 by enhancing the detoxification and excretion of the mycotoxin.
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 ...
The pozzolanic behaviour of compound-activated red mud-coal gangue has been investigated through TG, DTA, XRD, FTIR and {sup 27}Al MAS NMR. From viewpoint of reaction kinetics, it is found that the pozzolanic reaction mechanism of the compound-activated red mud-coal gangue-lime system is clearly consistent with diffusion control up to 14 days, and the reaction rate constant calculated from Jander equation decreases with the increase of CaO addition in the system. The hydration products formed in the red mud coal gangue-lime systems at ambient temperature are essentially aluminous C-S-H and Ca{sub 3}Al{sub 2}O{sub 6} center dot xH{sub 2}O. From TG analysis results, it is thought that the high amount of Ca(OH){sub 2} in the pastes of studied system is not conducive to the continual increase of non-evaporable water content of the hydration products. Of particular interest. {sup 27}Al MAS NMR proved to be an effective technique ...
The pozzolanic behaviour of compound-activated red mud-coal gangue has been investigated through TG, DTA, XRD, FTIR and 27Al MAS NMR. From viewpoint of reaction kinetics, it is found that the pozzolanic reaction mechanism of the compound-activated red mud-coal gangue - lime system is clearly consistent with diffusion control up to 14 days, and the reaction rate constant calculated from Jander equation decreases with the increase of CaO addition in the system. The hydration products formed in the red mud-coal gangue - lime systems at ambient temperature are essentially aluminous C-S-H and Ca3Al2O6.xH2O. From TG analysis results, it is thought that the high amount of Ca(OH)2 in the pastes of studied system is not conducive to the continual increase of non-evaporable water content of the hydration products. Of particular interest, 27Al MAS NMR proved to be an effective technique to obtain valuable information of Al[4] in C-S-H ...
Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625-5 x 10/sup -5/M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in dimished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into the red cell membrane. 7BETA-Hydroxycholesterol, 22-ketocholesterol, and 20 ..cap ...
Prototype tests conducted during the winter of 1989/90 have successfully demonstrated an economical design for air stripping volatile hydrocarbons from oily tanker ballast water. The prototype air stripper, developed for Alyeska's Ballast Water Treatment (BWT) facility in Valdez, Alaska, ran continuously for three months with an average removal of 88% of the incoming volatile organics. Initially designed to remove oil and grease compounds from tanker ballast water, the BWT system has been upgraded to a three-step process to comply with new, stringent regulations. The BWT biological oxidation process enhances the growth of bacteria present in the incoming ballast water through nutrient addition, aeration, and recirculation within a complete-mixed bioreactor. The average removal of BETX is over 95%, however, occassional upsets required the placement of a polishing air ...
Aim: Compounds such "9"9"mTc-MDP and "9"9"mTc-HEDP are used regularly in bone scintigraphy for metastasis detection. The therapeutics properties of beta emitter radionuclides like "1"5"3Sm, "1"6"6Ho and "1"7"7Lu has been widely reported in literature being "1"7"7Lu the less developed for medical applications. With the purpose of study different radiopharmaceuticals alternatives, for metastasis bone palliation, we have evaluated, on a comparative basis, the labeling of "1"5"3Sm-MDP, "1"5"3Sm-HEDP, "1"6"6Ho-MDP, "1"6"6Ho-HEDP, "1"7"7Lu-MDP and "1"7"7Lu-HEDP from the exhibited radionuclidic purity and biological distribution point of view. Material and Methods: The radionuclides were produced at La Reina Research Reactor, Chilean Nuclear Energy Commission. The radionuclidic purity was determined by gamma-Ray spectrometry. The labeling was accomplished with MDP (Plenum) and HEDP synthesized in-house. The in-vitro affinity of labeled compounds to ...
The conditions of production and the stability regions have been studied for the following crystallohydrates of trisubstituted uranyl orthophosphates: (UO_2)_3(PO_4)_2x6H_2O, (UO_2)_3(PO_4)_2x4H_2O, and (UO_2)_3(PO_4)_2xH_2O. Their thermal stability has been studied. It is shown that thermal dehydration of high-water hydrates at 220-240 deg C gives (UO_2)_3(PO_4)_2xH_2O. The anion composition and crystal structure of the compound remain constant up to 1000 deg C. The mixture of the composition of U_3O_8xU_3(PO_4)_4 is the final product of decomposition at 1000 deg C. The thermodynamic constants of dehydration processes have been calculated. A conclusion has been made about the polymer structure of the compound in which water is located between the uranylphosphate layers.
The solubility of Sn(IV) oxide was determined in a dilute NaClO{sub 4} solution with pH 2 through 12 at ambient temperature. Both oversaturation and undersaturation experiments were carried out in an inert gas glovebox where the concentration of the oxygen and carbon dioxide were less than 1 ppm. The solubility of Sn(IV) oxide was 3 {times} 10{sup {minus}8} mol/l at neutral pH, and increased at pH > 7.5. Equilibrium constants of soluble reactions were calculated from the experimental data, using curve fitting method. The study suggests that the solubility of Sn(IV) oxide would be higher than that provisionally used in current safety assessments of HLW disposal sites.
The solubility of Sn(IV) oxide was determined in a dilute NaClO_4 solution with pH 2 through 12 at ambient temperature. Both oversaturation and undersaturation experiments were carried out in an inert gas glovebox where the concentration of the oxygen and carbon dioxide were less than 1 ppm. The solubility of Sn(IV) oxide was 3 x 10"-"8 mol/l at neutral pH, and increased at pH > 7.5. Equilibrium constants of soluble reactions were calculated from the experimental data, using curve fitting method. The study suggests that the solubility of Sn(IV) oxide would be higher than that provisionally used in current safety assessments of HLW disposal sites.
Intermetallic compounds are regarded as highly promising for applications as high temperature structural materials. However, recent studies have demonstrated that a number of ordered alloys exhibit environmental embrittlement when tested in various environments at ambient temperature. When exposed to hydrogen gas or electrolytically charged with hydrogen, a significant ductility loss has been reported. The reaction of water vapor with reactive elements in the crack tip results in the generation of atomic hydrogen which diffuses from the surface to the interior and causes embrittlement. In this paper, the authors try to analyze the sensitivity of hydrogen embrittlement of ordered alloys based upon energetical considerations.
Sediment trap fluxes of solids, organic carbon, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were measured in Lake Superior in 1984 and 1985. Mass fluxes from surface waters ranged from 0.14 to 1.1 g/m{sup 2}{center dot}day and increased near the lake floor due to resuspension of surficial sediment and horizontal transport in the benthic nepheloid layer. Organic matter fluxes from surface water ranged from 60 to 90 mg of C/m{sup 2}{center dot}day, with {approximately}5% of organic carbon settling from surface waters accumulating in bottom sediments. Concentrations of PCBs and PAHs are enriched 10-100 times on settling particles relative to those on suspended particles. Resultant settling fluxes are 10-100 times greater for several PCB and PAH compounds than net accumulation rates in bottom sediments, indicating the effective and rapid recycling in the benthic region. ...
Clay-based materials can be cold-stabilized using binder and formed by extrusion. This paper deals with the properties of such materials under the influence of silico-aluminous flying ashes addition. Flying ashes are solid industrial wastes produced by coal combustion. Characteristics of ashes bearing clay-based products, such as dimensional stability, water and mechanical resistance, accelerated aging, are considerably improved with respect to simple clay-binder mixtures. This is principally due to a better hydration of the binder in ashes-bearing mixtures because of: a higher free-water availability as a consequence of the smaller specific surface of ash grains, the filler effect of ash grains which do not participate to the reactions, the specific property of silico-aluminous ashes that can fix the lime in presence of water to produce hydrated compounds. These ashes-bearing clay based materials can ...
The pilot area of the Vyngapour oil field allotted for MIOR tests contains three injection and three producing wells. These wells were treated in summer 1993 and 1994. Before, during, and after MIOR treatments on the pilot area the chemical compounds of injected and formation waters were studied, as well as the amount and species of microorganisms entering the stratum with the injected water and indigenous bacteria presented in bottomhole zones of the wells. The results of monitoring showed that the bottomhole zone of the injection well already had biocenosis of heterotrophic, hydrocarbon-oxidizing, methanogenic, and sulfate-reducing bacteria, which were besides permanently introduced into the reservoir during the usual waterflooding. The nutritious composition activated vital functions of all bacterial species presented in the bottomhole zone of the injection well. The formation waters from producing ...
The methods introduced for the field of cleaning waste water can be classified under various processes. Chemical oxidation is done with ozone, hydrogen peroxide and ultraviolet irradiation with subsequent biological decomposition. Another method is ultra-filtration with recovery of valuable materials or waste water ponds with algae biomass to decompose ammonium compounds, nitrates and phosphates. (EF) [Deutsch] Die auf dem Gebiet der Abwasserreinigung vorgestellten Methoden kann man in verschiedene Verfahren einordnen. Die chemische Oxidation erfolgt mit Ozon, Wasserstoff-Peroxid, UV Bestrahlung und anschliessenden biologischen Abbau. Eine andere Methode ist die Ultrafiltration mit Rueckgewinnung von Wertstoffen oder Abwasserteiche mit Algenbiomasse zum Abbau von Ammoniumverbindungen, Nitraten und Phosphaten. (EF)
Humic acids are considered problematically in drinking water because it can react readily with chlorine to form carcinogen compounds and its biological removal is much recommended. The scanning electron microscopy morphologies and optical parameters observed for natural humic acids (NHAs) extracted from different soils at Mitidja plain (Algeria) made them different from the commercial ones. Three of the most active strains of 19 actinomycetes were isolated and selected from surface soils at this plain. These strains were identified based on cultural characteristics and chemotaxonomic analysis and classified in the genus Streptomyces. Growth of these strains was assured on a poor liquid medium containing NHAs as carbon and nitrogen sources and degradation occur only in the presence of gluco...
Formation of oxidizing and reducing radicals was studied by pulse radiolysis of [Fe(CN)_6]"4"- - BrO_3"- - CN"- system in ethylene glycol - water solvent mixture. Oxidizing #centre dot#BrO_2 and BrO radicals formed by electron scavenging with #centre dot#BrO_2"- were identified and their reactions were investigated. The reaction of hydroxyl radicals with ethylene glycol leads to formation of reactive radicals with reducing properties and of compounds which reduce slowly in dark the ferricyanide formed in the reaction of #centre dot#BrO_2 radical with ferrocyanide. (author) 21 refs.; 7 figs.
The radioisotope production facilities and programs of the 86-Inch Cyclotron are reviewed in this presentation. The 86-Inch Cyclotron is designed to accelerate protons to a maximum energy of 22 MeV for internal targets. These protons are used to bombard metals that are electroplated, potted or soldered to water-cooled plates. Additionally, metals and inorganic compounds are bombarded in water-cooled tube targets. High radioisotope production rates are obtained by beam currents as large as 3 mA. Production rates for /sup 11/C, /sup 57/Co, /sup 67/Ga, /sup 68/Ge, /sup 109/Cd, and other isotopes are presented. The production of /sup 11/C for the carboxyl labeling of amino acids in cooperation with Oak Ridge Associated Universities is discussed. The 86-Inch Cyclotron is used for those programs requiring a larger beam current than is available from commercial cyclotrons.
Abstract Objectives- Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings- Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are mo...
Interaction of periodic and iodic acids with propyoneamide in aqueous solutions at 25 deg C has been studied. In the system iodic acid-propyoneamide-water formation of two compounds of the composition 6C_2H_5CONH_2#centre dot#HIO_3 and C_5H_5CONH_2#centre dot#HIO_3 is ascertained, for which concentrational boundaries of formation, density, melting points are determined. The system periodic acid-propyoneamide-water is referred to the simple eutonic type. By the method of IR spectroscopy it has been shown that oxygen atom of amide carbonyl group is the centre of propyoneamide protonation by iodic acid.
The Davis GSR Landfill (GSR) is listed by the U.S. Environmental Protection Agency on the National Priorities List. Preliminary on-site sampling results have demonstrated volatile organic compounds in ground water and surface water. The contaminants present in groundwater at this site are trichloroethylene, ethylbenzene, toluene, chloromethane, tetrahydrofuran, 1,1,1-trichloroethane, and 1,2 dichloroethane. GSR represents a potential public health concern to area residents. However, information available on this site is not currently adequate to determine if a public health concern exists to these residents. At a minimum, future investigations of this site should include a characterization of the site and site contaminants, and a characterization of the hydrogeology of the area.
The marked difference between the intra- and extracellular "3"1P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the "3"1P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethylphosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the "3"1P NMR resonances to shift to lower frequency in a manner ...
The solubilities of chlorodifluoromethane(R-22) and dichlorodifluoromethane(R-12) in organic solvents were measured in the range of low pressures and several temperatures(278-338 K). Organic solvents used in this system were olive oil and oleic acid. Henry`s law is applied in the lower temperature range and the solubilities of R-22 show negative deviations from Raoult`s law. In this study temperature and pressure dependence were correlated. The correlation of gas solubility data, using Krichevsky-Kasarnovsky equation and Van`t Hoff expression are obtained. Values of Henry`s constant, Partial enthalpy and partial entropy in organic solvents have been determined for both gases. The solubilities increase with increasing pressure and decreasing temperature and both gases are more soluble in olive oil than in oleic acid. The solubilities of R-22 in organic solvents ...
Flow Accelerated Corrosion (FAC) of Carbon Steel (CS) piping has been one of main issues in Light-Water Nuclear Reactor (LWRs). Wall thinning of CS piping due to FAC increases potential risk of pipe rupture and cost for inspection and replacement of damaged pipes. In particular, corrosion products generated by FAC of CS piping brought steam generator (SG) tube corrosion and degradation of thermal performance, when it intruded and accumulated in secondary side of PWR. To preserve SG integrity by suppressing the corrosion of CS, High-AVT chemistry (Feedwater pH9.8#+-#0.2) has been adopted to Tsuruga-2 (1160 MWe PWR, commercial operation in 1987) in July 2005 instead of conventional Low-AVT chemistry (Feedwater pH 9.3). By the High-AVT adoption, the accumulation rate of iron in SG was reduced to one-quarter of that under conventional Low-AVT. As a result, a tendency to degradation of the SG thermal efficiency was improved. On the other hand, it was clarified that ...
This document presents a conceptual design for a contingency interim measure (IM) for treatment of the public water supply system at Barnes, Kansas, should this become necessary. The aquifer that serves the public water supply system at Barnes has been affected by trace to low concentrations of carbon tetrachloride and its degradation product, chloroform. Investigations conducted on behalf of the CCC/USDA by Argonne National Laboratory (Argonne 2008a) have demonstrated that groundwater at the Barnes site is contaminated with carbon tetrachloride at concentrations exceeding the Kansas Tier 2 risk-based screening level (RBSL) and the EPA maximum contaminant level (MCL) of 5.0 {micro}g/L for this compound. The Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA) formerly operated a grain storage facility in Barnes, approximately 800 ft east-southeast of the public water supply ...
The disposition of three (1-/sup 14/C)-chlorododecanes (MCDD, PCDD I and PCDD II; 17.4%, 55.9%, and 68.5% chlorination) was studied in C57Bl mice. (1-/sup 14/C)-lauric acid (LA) was studied as reference compound. Fifty-two percent (MCDD), 32% (PCDD I), and 8% (PCDD II) of the radioactive doses were exhaled as /sup 14/CO/sub 2/ during 12 h after i.v. injection. Similar results were obtained after p.o. administration. In addition to a marked labelling of the liver and fat, the distribution patterns observed at 24 h after administration revealed an uptake of radioactivity in tissues with high cell turnover/high metabolic activity, e.g., intestinal mucosa, bone marrow, salivary glands and thymus. The concentration of radioactivity in these sites and the exhalation of /sup 14/CO/sub 2/, which were inverse to the degree of chlorination, indicate that the chloroalkanes are degraded to metabolites which can be utilized in the intermediary metabolism. A similar, although ...
A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H{sub 2}O{sub 2}/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation was obtained in a ...
A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H_2O_2/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation was obtained in a few minutes. ...
Before large-scale anthropogenetic emissions the environmental factors have been rather stable for thousands of years, varying yearly, seasonally and daily in rather regular manners around some mean values. In this century the emissions of CO{sub 2}, sulphur and nitrogen from society to atmosphere are changing both atmospheric and soil environment at rates not experienced before. The fluxes to soil affect the contents of plant available nutrients and solubility of toxic compounds in the forest soil. Additionally, the chemical state of soil environment is coupled to tree growth, litter production and nutrient uptake as well as to the activity of biological organisms in soil, which decompose litter and release nutrients from it. Trees have developed effective regulation systems to cope with the environment during the evolution. The resulting acclimations improve the functioning of the trees if the environmental factors remain within their range ...
The titanium stabilized austenitic steel similar to the type of 321 is sensitive to the stress corrosion crackingunder horizontal steam generator operating condition. SCC was observed under crevice corrosion parameters and has resulted in the transgranular or intergranular cracking at the both, components primary collectors and heat exchange tubes. The crevice environment is characterized by aggressive impurities and 'non aggressive' compounds. Sulfates and chlorides as aggressive species and silicates and alumino-silicates as 'non aggressive' species on the other hand are present in significant amount in the crevice environment under operating condition. Local water chemistry parameters were evaluated with MULTEQ Code. As input data the measured operational values of local and bulk environments have been used. The determined parameters were compared with the results of thread hole environment analyses and ...
This document is the combined Remedial Investigation and Feasibility Study Report for the Lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch River. This area has received hazardous substances released over a period of 50 years from the U.S. Department of Energy`s Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received containments, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. ...
Plutonium and minor actinides produced as by-products of the UO_2 nuclear cycle could be considered as waste or energy source depending on the strategy selected in the nuclear energy programme. Considering Pu and Minor Actinides as a source, they can be burned in existing water reactor for diminishing the radiotoxicity of the spent fuel, it is necessary to use 'inactive' materials as matrix like ThO_2. ThO_2 matrix has demonstrated its Pu burning efficiency and higher corrosion resistance than UO_2. Uranium-plutonium mixed oxide (MOX) fuel efficiency is low because the presence of U in MOX results in the creation of some new Pu under irradiation. The dissolution behaviour of irradiated (Th,Pu)O_2 pellets with burn-up of 38.8 MWd/kg Th has been studied in carbonated (20 mM HCO_3"-), deionised and granite ground water solution in a hot cell. The dissolution behaviour of Th, Pu, U and Np was studied in order to find out whether radionuclides ...
Arsenic was predominantly present as inorganic arsenite in the fronds of the hyperaccumulator Chinese brake. - Arsenic speciation is important not only for understanding the mechanisms of arsenic accumulation and detoxification by hyperaccumulators, but also for designing disposal options of arsenic-rich biomass. The primary objective of this research was to understand the speciation and leachability of arsenic in the fronds of Chinese brake (Pteris vittata L.), an arsenic hyperaccumulator, with an emphasis on the implications for arsenic-rich biomass disposal. Chinese brake was grown for 18 weeks in a soil spiked with 50 mg As kg"-"1 as arsenate (AsO_4"3"-), arsenite (AsO_3"3"-), dimethylarsinic acid (DMA), or methylarsonic acid (MMA). Plant samples were extracted with methanol/water (1:1) and arsenic speciation was performed using high performance liquid chromatography coupled with atomic fluorescence spectrometry. The impacts of air-drying on arsenic species and ...
All MBI bending magnets in each of the two LHC injection transfer lines will be powered in series. The limited output voltage of existing power converters lead to an unusual coil design avoiding external return bus-bars by combining two overlapping half-coils, electrically separated, with 3 1/2 turns each in a monolithic structure. The voltage between turns in one coil can reach up-to 3.6 kV. The coil has been designed with particular care for obtaining high interturn and ground insulation. Flux-free soldering of connections with plug-in cone sleeves is applied, allowing to execute water cooled current connections as prolongation of the coil conductor. Epoxy compound polymerization in the impregnation mould is obtained by passing overheated water in regulated cycles through the water circuit of the coil conductor. We describe the design basics as well as various test results of pre-series and series ...
Mechanisms that govern transport, accumulation and toxicity of persistent pollutants at interfaces in aquatic ecosystems were the foci of this thesis. Specific attention was paid to humic substances, their occurrence, composition, and role in exchange processes across interfaces. It was concluded that: The composition of humic substances in aquatic surface microlayers is different from that of the subsurface water and terrestrial humic matter. Levels of dissolved organic carbon (DOC) in the aquatic surface microlayer reflect the DOC levels in the subsurface water. While the levels and enrichment of DOC in the microlayer generally show small variations, the levels and enrichment of particulate organic carbon (POC) vary to a great extent. Similarities exist between aquatic surface films, artificial semi-permeable and biological membranes regarding their structure and functioning. Acidification and liming of freshwater ecosystems affect DOC:POC ...
The deposit of radioactive corrosion products in the cooling systems of nuclear reactors becomes a serious problem for the personnel of facilities. Crud has an important role in the process of depositing radioactive corrosion products. The main components of crud are hematite, magnetite, nickel ferrite and so on, and the particles of these oxide compounds are distributed in water. Most of the behavior of crud are still not known. As for the mechanism of the production of crud, the Potter-Mann model has been proposed. However, the precipitation process of iron ions in water is unknown. The crud is defined as the particles filtered by 0.45 micrometer millipore filters. However, it is not known whether there are crud particles smaller than this size. The crud particles can be adsorbed on the filters by the surface electrochemical interaction. The adsorption of cations to crud particles was studied. The adhesion of crud ...
The electrochemical behavior of lanthanide oxides in molten alkaline chloride media is of great concern in pyrochemical processes for advanced nuclear fuel cycle. We have studied the solubilities of various lanthanide oxides in LiCl-KCl eutectic melt. In general, lanthanide oxides appeared to be insoluble/sparingly soluble in LiCl-KCl eutectic at 723 K. However, europium oxide exhibited an abnormal behavior in solubility and redox chemistry. The solubility of europium oxide was measured to be 1-2 order of magnitude higher than those of other lanthanide oxides. This abnormal solubility may be attributable to different electrochemical behavior of europium in the same experimental conditions. Most lanthanides ion exists as trivalent oxidation states. However, we observed divalent europium dissolved in LiCl-KCl molten salt by applying electron paramagnetic resonance(EPR) spectroscopy. ...
Vacuum glazing consists of an evacuated space between two sheets of glass. Vacuum glazing has a large effect on energy savings in houses and buildings. Vacuum glazing can achieve higher insulating performance than conventional insulated glazing. Nippon Sheet Glass has successfully developed conventional vacuum glazing. In this study we investigated an advanced form of vacuum glazing. Its thermal insulation ability is equivalent to 100 mm thick glass wool thermal insulation. This vacuum glazing contained a SnO_2:F low emissivity surface. The influence of the residual gas in a vacuum space on heat flow is important to performance. For long-term thermal stability, it is very important to maintain vacuum stability. To understand this better, we studied the behavior of outgassing from the inside glass surfaces exposed to an external energy source. We have studied the behavior of outgassing from a glass surface using a Nd:YAG laser (operated at 355 nm wavelength) and Q-mass spectroscopy in ...
The composition of alkaline and neutral boric acid containing evaporator concentrates resulting from the treatment of radioactive waste water in nuclear power plants with WWER reactors is described as well as the processing of these concentrates to a product suitable for final disposal. Tests with mock solutions of these evaporator concentrates have been performed at the laboratory and teststand scale to produce a dry residue by continuous thickening, which can be processed into a highly leach resistant product, suitable for final disposal, by cementation. Ca-compounds must be added to the evaporator concentrates prior to the drying in an rotary thin-film evaporator (RTFE). The tests showed that neutral evaporator concentrates can be dried in a RTFE with addition of small amounts of Ca-compounds. The alkaline evaporator concentrates with high boric acid and total salt load require a multiple amount of ...
Natural rubber latexes were vulcanized by ..gamma..-rays with two polyfunctional monomers, neopentylglycol diacrylate (A-NPG) and dimethacrylate (NPG). In comparison with A-NPG, NPG was more soluble in rubber particles, but it was less effective as an accelerating agent for the vulcanization because of the smaller rate of polymerization. On the other hand, the colloidal stability of the latex containing A-NPG was low because it was localized on the surface of rubber particles due to its poor solubility to the particles. The solubility of A-NPG was improved by adding A-NPG with solvents. The maximum tensile strength of the irradiated latex film was 350 kg/cm/sup 2/ at 3 Mrad.
Natural rubber latexes were vulcanized by #gamma#-rays with two polyfunctional monomers, neopentylglycol diacrylate (A-NPG) and dimethacrylate (NPG). In comparison with A-NPG, NPG was more soluble in rubber particles, but it was less effective as an accelerating agent for the vulcanization because of the smaller rate of polymerization. On the other hand, the colloidal stability of the latex containing A-NPG was low because it was localized on the surface of rubber particles due to its poor solubility to the particles. The solubility of A-NPG was improved by adding A-NPG with solvents. The maximum tensile strength of the irradiated latex film was 350 kg/cm"2 at 3 Mrad. (author).
Fractal dimensional analysis was employed to obtain a quantitative measure of the morphology of polymer networks formed by UV irradiation induced polymerization of photo-reactive mesogenic monomers dissolved in a liquid crystal host medium. The fractal dimensions obtained, may be interpreted by polymer network growth following a percolation-like model for monomer concentrations well below the solubility limit. On passing the solubility limit, the polymerization process changes from a (radical chain) solution polymerization to a dispersion polymerization, with fractal dimensions decreasing and suggesting a cluster-cluster aggregation process for monomer concentrations above the solubility limit, similar to the aggregation of colloidal particles.
Modeling calculations on the solubility of americium have indicated that basic americium carbonate, and not americium trihydroxide, is the solubility-controlling solid in the pH range from 6 to 10 under the influence of atmospheric CO{sub 2}. The solubility of crystalline {sup 243}AmOHCO{sup 3} has been investigated in batch experiments in near-neutral and basic solutions as a function of dissolution time in 0.1 M NaClO{sup 4} at room temperature under oxic conditions. After the solutions reached steady-state conditions, the influence of dissolved solids on the americium concentration in the supernatant solution was studied by utilizing several experimental methods to separate the solution phase from the solid. The solids were characterized by X-ray powder diffraction analysis.
In ozonization of polyfunctional and humic acids in icy acetic acid the whole of organic carbon can turn into a soluble form. Mono - and dicarboxylic acids of normal structure were found in the products of ozonization.
The tetrapeptide KDEL is commonly found at the C terminus of soluble proteins of the endoplasmic reticulum (ER), and it contributes to their localization by interacting with a receptor that recycles...Full Text Available
... 5.9-585/T; thermal stability; solubility in liquid nitrogen, oxygen and Freons; molar extinction coefficients in the visible range and EPR spectrum. ...
The preparation of neem oil microemulsion and its acaricidal activity in vitro was developed in this study. In these systems, the mixture of Tween-80 and the sodium dodecyl benzene sulfonate (SDBS) (4:1, by weight) was used as compound surfactant; the mixture of compound surfactant and hexyl alcohol (4:1, by weight) was used as emulsifier system; the mixture of neem oil, emulsifier system and water (1:3.5:5.5, by weight) was used as neem oil microemulsion. All the mixtures were stired in 800rpm for 15min at 40^oC. The acaricidal activity was measured by the speed of kill. The whole lethal time value of 10% neem oil microemulsion was 192.50min against Sarcoptes scabiei var. cuniculi larvae in vitro. The median lethal time value was 81.7463min with the toxicity regression equations of Y=-6.0...
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 ...
The dodecanuclear rhenium anionic complex with terminal hydroxo ligands [Re12CS17(OH)6]6? was obtained by the reaction of K6[Re12CS17(CN)6]?20H2O with molten KOH at 300 ?C. The cluster complex was crystallized as a potassium salt from aqueous solution. The reaction between K6[Re12CS17(OH)6]?4H2O and Na2S2O4 in water under reflux results in the formation of the complex Na12[Re12CS17(SO3)6]?48.5H2O. Both new compounds were characterized by single-crystal X-ray diffraction, elemental analyses and IR spectroscopy. The electronic structure of [Re12CS17(OH)6]6? was also elucidated by DFT calculation
Implementation of Noble Metal Chemical Application (NMCA) in a Boiling Water Reactor (BWR) requires injection of a noble metal compound while the reactor is idle at hot shutdown conditions. In order to minimize outage time, utilities are very pro-actively finding ways to reduce the number of critical path tasks. One of these tasks is to remove some containment vessel drywell head bolts during the NMCA idle time. This, thereby, saves the utilities outage time, or they can perform other tasks as desired. Using design basis conditions and state-of-the-art analytical techniques, detailed finite element stress analyses of the closure region are performed. Two acceptance criteria are evaluated. The first is that contained within Section III of the ASME Code for allowable stresses. The second relates to leak tightness, i.e., with bolt removal the joint must still remain leak tight. This paper describes the activities performed to justify bolt removal ...
The commercial solid phase microextraction (SPME) fibers are not stable enough in organic solvent and tend to swell and strip off from the silica fiber in the high performance liquid chromatography (HPLC) mobile phase, and therefore the application of SPME coupled online with HPLC is limited. In this study, an SPME fiber coated with single walled carbon nanotubes (SWCNTs), prepared by means of electrophoretic deposition, was coupled on line to HPLC for the determination of four endocrine-disrupting compounds, i.e. bisphenol A (BPA), estrone (E(1)), 17?-ethynylestradiol (EE(2)) and octylphenol (OP), in aqueous samples. The results showed that the SWCNTs coating on the prepared fiber did not swell and strip off from the platinum fiber throughout the experiment, thus indicating a high resistance to the HPLC mobile phase, the mixture of water and acetonitrile. The SWCNTs fiber had similar (for OP) or higher (for BPA, EE(2) and E(1)) extraction ...
A meeting was held on October 15, 16, 17, 1990 to discuss the state of tritium safety and environmental effects. The meeting was organized with the help of the International Energy Agency planning committee consisting of K. Steinmetz, Y. Seki, G. Nardella, and G. Vivian. Representative of tritium production facilities and heavy water reactor power production were also involved. The meeting was organized to address seven topics in tritium safety that were thought to require further work. The topics were: (1) materials science, (2) environmental models, (3) environmental model validation, (4) tritiated organic compounds, (5) human dosimetry, (6) tritium sampling and measurement, and (7) long-term environmental databases.
By methods of vibrational (infrared, Raman) and PMR spectroscopy, crystallohydrate forms of monosubstituted uranyl orthophosphate have been examined. The vibrational frequencies of the groupings from the compounds were identified. The existence of non-equivalent H_2PO_4"--groups in the substances under investigation was ascertained. It has been suggested that one of them is a bridged group, and the other is the end group. A fragment of the VO_2(H_2PO_4)_2 hydrate structure is given, its main constituents being uranylphosphate chains. The analysis of water vibrations assumes coordination of one mole of H_2O in VO_2(H_2PO_4)_2:3H_2O to uranium, while two other molecules are only hydrogen-bonded with phosphate anions. Absorption within the region of 2100-2550 cm"-"1 is assigned to vibrations of O...H...O groupings.
Among the several chemical processes conducted for the removal of organic matter present in wastewaters coming from some agro-industrial plants (wine distilleries, olive oil mills, etc), the oxidation by ozone has shown a great effectiveness in the destruction of specially refractory pollutants: it is demonstrated that the biodegradability of those wastewaters increases aflcer an ozonation pretreatment. Their great pollutant character is imputed to the presence of some organic compounds, like phenols and polyphenols, which are toxic and inhibit the latter biological treatments. In this research, a competitive kinetic procedure reported by Clurol and Nekouinaini is applied to determine the degradation rate constants by ozone of several phenolic acids which are present in the wastewaters from the olive oil obtaining process. The resulting kinetic expressions for the ozonation reactions are useful for the successful design and operation of ozone reactors in ...
This document reports on the work done by the Separations Science and Technology Programs of the Chemical Technology Division, Argonne National Laboratory, in the period April-September 1992. This effort is mainly concerned with developing the TRUEX process for removing and concentrating actinides from acidic waste streams contaminated with transuranic (TRU) elements. The objectives of TRUEX processing are to recover valuable TRU elements and to lower disposal costs for the nonTRU waste product of the process. Two other projects are underway with the objective of developing (1) a membrane-assisted solvent extraction method for treating natural and process waters contaminated by volatile organic compounds and (2) evaporation technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process.
This paper studies the analytical application of europium (III)-morin complex which is formed in alkaline medium and has an intense color. The extent of europium extraction was determined by adding to the extract a morin solution in isoamyl alcohol in a 50-100-fold excess with respect to europium. The dependence of the optical density of the extracts on the ph in the system europium (III)-morin-water-organic solvent for different excesses of the reagent is shown: this indicates formation of two extractable complexes, one being dominant in the pH range 4-7, the other at pH greater than or equal to 8.5. The extraction of the europium (III)-morin complex from alkaline solution is used for direct extraction-photometric determination of europium(III) in compounds of elements having amphoteric properties or forming amines (Zns, Mo0/sub 3/).
A process and apparatus for the production of coke, asphalt and jet fuel m a feed of fossil fuels containing volatile carbon compounds therein is disclosed. The process includes the steps of pyrolyzing the feed in an entrained bed pyrolyzing means, separating the volatile pyrolysis products from the solid pyrolysis products removing at least one coke from the solid pyrolysis products, fractionating the volatile pyrolysis products to produce an overhead stream and a bottom stream which is useful as asphalt for road pavement, condensing the overhead stream to produce a condensed liquid fraction and a noncondensable, gaseous fraction, and removing water from the condensed liquid fraction to produce a jet fuel-containing product. The disclosed apparatus is useful for practicing the foregoing process. the process provides a useful method of mass producing and jet fuels from materials such as coal, oil shale and tar sands.
To eliminate their classical brittleness and flexibility problems zein films were plasticized by incorporation of different phenolic acids (gallic acid (GA), p-hydroxy benzoic acid (HBA) or ferulic acids (FA)) or flavonoids (catechin (CAT), flavone (FLA) or quercetin (QU)). The use of GA, CAT, FA and HBA at 3 mg/cm2 eliminated the brittleness of films and gave highly flexible films showing elongations between 135% and 189%, while FLA and QU caused no considerable effect on film elongation. The films containing FA and HBA showed extreme swelling and lost their structural integrity when hydrated in distilled water. In contrast, CAT and GA containing films maintained their integrity following hydration. Most of the GA (up to 93%) and a considerable portion of CAT (up to 60%) in the films exis...
Summaries are included of research contracts which expired prior to Dec. 31, 1960. The contracts were concerned with investigations of: electrophysiological responses of biological systems in nerve cells to irradiation with small doses of ionizing radiations; the mode of the protective action of certain sulfhydryl compounds against radiation effects on the synthesis of deoxyribonucleic acid, using tritium-labeled thymidine; development of a bubble chamber method of monitoring and dosimetry for Low fast neutron fluxes; effects of incorporated radioisotopes on the stability of genetic materials; interrelation of root and leaf absorption of radioisotopes in herbaceous plants; uptake of radioactive wastes by lowland rice from soils contaminated by irrigation water, and decontamination of the rice; and comparison between mutation rates induced by acute and chronic gamma irradiations. (B.O.G.)
An experimental and theoretical study of heat and mass transfer analogy and a comparison of that to a binary liquid mixture evaporation is presented. Common organic solvents, ethanol and n-heptane, were used to form an alcohol - hydrocarbon mixture. Studies were carried out in a horizontal rectangular channel having air flow velocities of 0.2 - 0.9 m/s. Heat transfer coefficients were measured with a copper plate resistor and mass transfer coefficients with a square pool. The heat and mass transfer analogy is presented for a system having two evaporating compounds with a fixed value of air flow and verified by measuring and comparing mass transfer coefficients for distilled water with air flow velocities of 0.2 - 0.9 m/s. An illustrative example of the use of the theory for industrial ventilation is presented. (author)
Hundreds of organic byproducts of chlorination are now known to occur in drinking water along with the trihalomethanes. About twenty of these appear to be found with sufficient frequency and in sufficient concentration to attract consideration for regulations. These include chloral hydrate, chloropicrin, a trichloropropanone, haloacetonitriles, and haloacetic acids. Trihalomethane concentrations do not serve as good predictors of concentrations of these other byproducts because their conditions of formation vary widely. This is especially true when pH is changed. Treatment strategies for control of these byproducts including the trihalomethanes are: Remove the compounds after they are formed; Remove precursors; and Use other disinfectants. Current evidence supports the idea that precursor removal processes effective for trihalomethane control may be effective for the other byproducts as well.
The potential of the yeast Candida tropicalis and Candida guillermondii was evaluated and an isolated partnership of microorganisms of waters of the Medellin River, conformed by two bacteria and one leavening, to degrade the content of organic matter present in wine produced by the factory of Licores and Alcoholes de Antioquia (FLA) in aerobic process with biomass production. For each one of the microorganisms in study this capacity of removal in units of chemical demand of oxygen was quantified (CDO); in addition, parameters were analyzed such as yield of the biomass in relation to the removed CDO and to total reducing sugars (TRS) consumed, time of fermentation and speed of growth different dilutions from wine. Also the possible inhibition was analyzed that the present phenolic compounds in this wine can cause in the biological process of degradation.
Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds 13CO, C18O, o-H2-18O, HCO+, CS, CH, and NH have been used to derive the physical and chemical conditions in the PDR, in particular the water abundance. The 13CO, C18O, o-H2-18O, HCO+ and CS observations are well described assuming that the emission is coming from a dense (n=5E6 cm-3, N(H2)>1E22 cm-2) layer of molecular gas around the UC HII. Based on our o-H2-18O observations, we estimate an o-H2O abundance of ~2E-8. This is the average ortho-water abundance in the PDR. Additional H2-18O and/or water lines are required to derive the water abundance profile. A lower density envelope (n~1E5 cm-3, N(H2)=2-5E22 cm-2) is responsible for the ...
In this Brief Report, we analyze a generalized theory of massless scalar QED{sub 2} and show that, unlike the conventional scalar QED{sub 2}, it is free from infrared divergence problems. The model is exactly soluble and may describe, in a (1+1)-dimensional space-time, noninteracting spin-one tachyons. {copyright} {ital 1999} {ital The American Physical Society}
The 3D modeling of the thermal hydraulic processes and soluble impurity distribution in the horizontal steam generator PGV-1000 was fulfilled with the thermal hydraulic code STEG. Steady-state operation of horizontal seam generator PGV-1000 was analyzed at nominal power. The modeling of the soluble impurity distribution was fulfilled on the basis of the previous thermal hydraulic modeling results. The processes of the soluble impurity deposition on the steam generator tube bundles and deposits outwash were considered in the mathematical model of the code. The modeling was fulfilled for horizontal steam generators with different peculiarities in construction. Calculation results were compared with experimental results obtained at NPP. The agreement between calculated and experimental results is quite reasonable. Results of modeling are sensible to the peculiarities of the horizontal steam generator construction and ...
The open circuit potential (OCP) of stainless steels immersed in natural waters generally increases with time. This phenomenon is strongly linked to the formation of a bio-film on the surface. Several studies have proved that the bio-film modifies the reaction of reduction of dissolved oxygen and that it acts mainly on the cathodic processes. One of the hypotheses explaining the action of the bio-film involves certain bacteria which use dissolved oxygen and extracellular enzymes to produce reactive oxygen species. Among this kind of metabolites is hydrogen peroxide H{sub 2}O{sub 2}. This compound interacts with the passive layer of stainless steels and affects their electrochemical behaviour, even when the chloride concentration is low. The aim of this work is to study the influence of an enzymatic reaction (of the oxidoreductase type) on anodic and cathodic processes on AISI 316L stainless steel. Experiments are carried out in two artificial ...
Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the cathodic hydrogen charging under coulombic equivalence. The precipitates at metal-oxide interface could act not only as ...
Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the cathodic hydrogen charging under coulombic equivalence. The precipitates at metal-oxide interface could act not only as ...
Mining lakes are of a world-wide challenging problem caused by the well known acid mine drainage (AMD) and the dynamics of it. In the past, there was no possibility to monitor these mining lakes for an investigation of chemical and biological parameters. But, in general, remote sensing methods are suitable for a monitoring of natural lakes, and now, at the first time, those can be used for a distinction of acid mining lakes in central Germany into different types. In acid mining lakes unusual absorption and scattering properties exist due to the water constituents which are quite different in their optical properties to those of natural lakes. The artificial lakes show high concentrations of metal ions and compounds. This fact was used to discriminate the mining lakes into initial stage, early stage, transitional state and late state. The result is a map of the area where the mining lakes are presented at their current stage. The present method ...
Small unilamellar vesicles which form when gel-state long-chain phosphatidylcholines are mixed with micellar short-chain lecithins undergo an increase in size as the long-chain species melts to its liquid-crystalline form. Analysis of the vesicle population with quasi-elastic light scattering shows that the particle size increases from 90-A radius to greater than 5000-A radius. Resonance energy transfer experiments show total mixing of lipid probes with unlabeled vesicles only when the Tm of the long-chain phosphatidylcholine is exceeded. This implies that the large size change represents a fusion process. Aqueous compartments are also mixed during this transition. 31P NMR analysis of the vesicle mixtures above the phase transition shows a great degree of heterogeneity with large unilamellar particles coexisting with oligo- and multilamellar structures. Upon cooling the vesicles below the Tm, the original size distribution (e.g., small unilamellar vesicles) is obtained, as monitored by ...
The watersoluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When isoelectric vesicles were ...
The purpose of the invention is a process for the production of a particularly finely divided, homogeneous transition metal phosphide and transition metal chalcogenide of Daltonian stochiometry by the conversion of at least one powder transition metal or a transition metal alloy with phosphorus or with a chalcogen at raised temperature, which is characterized by the fact that the conversion is carried out in the presence of at least one inert finely divided auxiliary material which is soluble in water and does not sinter together at the reaction temperature, and that the conversion produce removes the auxiliary material. Even relatively small quantities of the auxiliary material are sufficient to ensure rapid and homogeneous conversion of the reaction partners to the reaction product having a large surface. A ratio of 1 part by volume of a mixture of a transition metal and phosphorus or chalcogen to 1 part by volume of finely divided auxiliary ...
The first part of the conference dealt with environmental effects of using coal. Papers dealt with the use of fly ash in agriculture and its effect on plant growth; the effect of airborne emissions on fish and wildlife resources, on watersheds, and on airsheds; the effects of surface mining on the ecology; blast effects; and health hazards associated with coal. The session on policy studies addressed the issue of cost of synthetic fuels and discussed the state and federal pollution regulations on burning coal and waste disposal. The session on combustion presented papers on atmospheric and pressurized fluidized-bed combustion for industrial and utility boilers. It also included papers on MHD power plants, coal-oil and coal-water mixtures, emission characterization and control, and catalytic combustors. The design of gasification plants, reaction kinetics, specific heats of coals and chars, simultaneous production of liquid and gaseous fuels, and economics of fuel ...
The first part of the conference dealt with environmental effects of using coal. Papers dealt with the use of fly ash in agriculture and its effect on plant growth; the effect of airborne emissions on fish and wildlife resources, on watersheds, and on airsheds; the effects of surface mining on the ecology; blast effects; and health hazards associated with coal. The session on policy studies addressed the issue of cost of synthetic fuels and discussed the state and federal pollution regulations on burning coal and waste disposal. The session on combustion presented papers on atmospheric and pressurized fluidized-bed combustion for industrial and utility boilers. It also included papers on MHD power plants, coal-oil and coal-water mixtures, emission characterization and control, and catalytic combustors. The design of gasification plants, reaction kinetics, specific heats of coals and chars, simultaneous production of liquid and gaseous fuels, and economics of fuel ...
The decision of the United Kingdom to adopt a policy of solidification of high level waste had led to renewed interest in vitrification. The HARVEST process chosen is an adaptation of the FINGAL concept developed at Harwell 15 years ago. Because of certain changes in engineering design and differences in the composition of the waste, additional chemical engineering data are required for HARVEST. The new inactive pilot plant has been built to provide this information. Its size is virtually full-scale and batches of glass up to 1 tonne can be manufactured in vessels of diameter up to 750mm. Five glass-making runs have been carried out. Attention has concentrated on the performance of the off-gas system which employs wet methods. Carry-over of solids occurs, primarily as a result of physical entrainment. The carry-over of synthetic fission products is improved from 2.5 to 0.1% by directing the feed down the vessel walls. Most of the entrained solids is caught in the condensate which gives ...
Gadolinium nitrate has been employed in Indian nuclear reactors for the first time as soluble neutron poison in the heavy water moderators of the 540 MWe PHWRs TAPS 3 and 4, as a fast acting secondary shut down system (SDS-2); and also for reactivity shim. For this purpose, the moderator purification system is currently equipped with special ion-exchange columns/schemes, developed by present authors. However, for gadolinium removal from moderator in the post SDS-2 scenario, the two stage ion-exchange - cation bed operation followed by mixed bed operation - results in low pH conditions persisting in the moderator for a few hours, which gives rise to certain operational problems. The present paper describes a mixed bed ion-exchange scheme employing macro-porous strong acid cation and macro-porous weak base anion resins, which has been developed to eliminate acidic conditions and gives a better pH control. The cation to anion capacity ratio in the ...
The present study was carried out during two successive seasons of 2005 and 2006 seasons on"Montakhab El-Kanater"guavas and"Hachiya"persimmons.two different experiments were studied, the first one for pre harvest and second post harvest. Regarding pre harvest experiment,hand or chemical flower thinning by urea or ethrel and date of fruit picking (maturity) were evaluated on both guavas and persimmons.All flower thinning treatments increased fruit set,total yield,average fruit weight and decreased fruit abscission.However,a great effect on fruit quality and chemical compositions were also found with flower thinning treatments. Chemical flower thinning was more effective than hand thinning in improving yield and quality in "Montakhab El-Kanater"guavas and "Hachiya"persimmons. However,early maturation(120 and 150 days for guava and persimmon respect.) produced poor fruit quality.Whereas, medium maturity(130 and 180 days for guava and persimmon respect.) produced fruit with high ...
We describe the synthesis of metal-chelating polymers (MCPs) with four different pendant polyaminocarboxylate ligands (EDTA, DTPA, TTHA, DOTA) and an orthogonal end-group, either a fluorescein molecule or a bismaleimide linker for antibody attachment. Polymer characterization by a combination of (1)H NMR, UV/vis absorption measurements, and thermal gravimetric analysis (TGA) indicated that each chain of the fluorescein-terminated polymers contained one dye molecule. These polymer samples were loaded with three different types of lanthanide ions as well as palladium and platinum ions. The numbers of metal atoms per chain were determined by a combination of UV/vis and conventional ICP-MS measurements. The experiments with lanthanide ions demonstrated that a net anionic charge on the polymer is important for watersolubility. These experiments also showed that at least one type of lanthanide ion (La(3+)) is capable of forming a bimetallic complex ...
Among the three modifications of calcium sulfite hemihydrate, two of them, hexagonal ..beta..-CaSO/sub 3/.1/2H/sub 2/O with a rhombohedral lattice and ..gamma..-CaSO/sub 3/.1/2H/sub 2/O with a simple triangular hexagonal lattice, were found in the authors' recent work. By heating ..cap alpha..- and/or ..gamma..-hemihydrate at 330-360/sup 0/C in a nitrogen atmosphere, the orthorhombic anhydrate ..cap alpha..-CaSO/sub 3/ was formed, with lattice constants of 6.472, 15.93, and 23.44 angstrom for a, b, and c respectively, while the body-centered tetragonal anhydrate ..beta..-CaSO/sub 3/, with lattice constants of 15.68 and 19.44 angstrom for a and c respectively, was formed by heating the ..beta..-hemihydrate. The dehydration of three hemihydrates and the hydration of two anhydrates were discussed. Calcium sulfite hemihydrate (CaSO/sub 3/.1/2H/sub 2/O) is useful as an architectural material since it has a high thermal stability and a low water ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are watersoluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with [{sup 99m}Tc(pap){sub 3}]{sup +} ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are watersoluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with ["9"9"mTc(pap)_3]"+ showing elevated ...
Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the ...
Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to ...
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 salt where the /sup 13/C NMR signal ...
An interest in electronic materials has led me to investigate new synthetic approaches to III-V' type semiconducting (13-15, current IUPAC designation for B and N groups in the Periodic Table) and magnetic (3-15) compounds. It is now possible to prepare binary (GaAs and GdP) and ternary mixed-metal (Al[sub x]Ga[sub 1-x]As) and mixed-pnictide (GaP[sub x]As[sub 1-x]) compounds in seconds from rapid, low-temperature-initiated metathesis reactions between a metal (III) trihalide and a trisodium pnictide, exemplified by MX[sub 3] + Na[sub 3]Pn [yields] MPn + 3 NaX, where M is Al, Ga, In, (Al,Ga), or a lanthanide; X is F, Cl, or I; and Pn is P, As, Sb, or (P,As). The precursors are mixed together in a dry box and ignited by light grinding with a mortar and pestle, or by brief, local heating from a hot filament. These reactions are very exothermic (calculated [Delta]H[sub rxn] (GaAs) = 138 kcal/mol) and typically reach temperatures in excess ...
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The work presented in this report is a continuation and expansion of a previous study. The aim of the work is to provide background information about pitting corrosion of copper for a safety analysis of copper canisters for final deposition of radioactive waste. A mathematical model for the propagation of corrosion pits is used to estimate the conditions required for stationary propagation of a localised anodic corrosion process. The model uses equilibrium data for copper and its corrosion products and parameters for the aqueous mass transport of dissolved species. In the present work we have, in the model, used a more extensive set of aqueous and solid compounds and equilibrium data from a different source. The potential dependence of pitting in waters with different compositions is studied in greater detail. More waters have been studied and single parameter variations in the composition of the water ...
{sup 60}Co is produced as an activation product and is present in the low-level aqueous radioactive waste released from the La Hague plant. At present, the concentration in the sea (non filtered at 0.45 {mu}m) at the Goury site are close to or even below, the detection limit: 0.2 mBq.l{sup -1}. The {sup 60}Co speciation depends on the type of effluent considered: in the effluent A ('active'), the cobalt is in the form of a stable trivalent complex; in the effluent V (to be checked), the cobalt is in majority (50% of the activity release) in the form of particles (>0.45 {mu}m), and then in the form of two soluble species: ionic divalent (Co{sup 2+}) and some stable complexes. The evolution of the reprocessing techniques used does not affect the speciation. So, since the nuclear reprocessing plant started at the La Hague plant in 1966, the chemical species discharged in the sea shows time variation related to the evolution of the type of ...
We prepared macromer-grafted polymers (MGPs) containing suitable polymer side chains for improving solubility and pyrene units for improving adsorption on multiwalled carbon nanotube (MWCNT) surfaces, and demonstrated that these MGPs act as MWCNT solubilizers that improve solubility of MWCNTs in typically poor solvents such as alkanes and that improve flowability of polymer/MWCNT composites. The polydimethylsiloxane (PDMS)-MGPs, synthesized using PDMS macromers and pyrene-containing monomers, improved solubility of MWCNTs not only in chloroform but also in hexane, which is a poor solvent for MWCNTs. Moreover, the addition of PDMS-MGP-adsorbed MWCNTs (MWCNT/PDMS-MGPs) to epoxy resin monomers or polybutylene terephthalate (PBT) drastically reduced the viscosity of the obtained epoxy resin mo...
The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.
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 ...
This feasibility study of the uve Institut fuer Technische Chemie und Umweltschutz GmbH discusses the scientific and technical fundamentals of a catalytic process for complete removal of organic pollutants (PAH, H-HC, PCB, phenols, nitro-aromatics and organometallic compounds, e.g. from polluted soil and groundwater) by thermal-catalytic cracking and conversion into simple gases. The process is based on the catalytic reaction of the hydrocarbon compounds with water vapour in the temperature range of 700-900 degrees centigrade. The resulting gas mixtures consist mainly of hydrogen, carbon monoxide, carbon dioxide and methane which can be used as fuels, e.g. for heating or in gas engines. The process is an alterntive to combustion. It is therefore well suited whenever the pollutant to be removed is already mixed with water or water vapour and wherever in-situ removal would be too ...
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Breast cancer is a leading cause of female deaths worldwide. In Malaysia, it is the most common form of female cancer while Infiltrating ductal carcinoma (IDC) is the most common form of breast cancer....Full Text Available
The production of an intramuscular (IM) injection of natural progesterone would provide a safer solution than using semi synthetic progesterone. However, disadvantages such as low solubility and a short...Full Text Available
Early on, intriguing biological activities were found associated with the EETs using in vitro systems. Although the EETs other than the 5,6-isomer, are quite stable chemically,...Full Text Available
Photosynthetic (Ps) electron transport pathways often contain multiple electron carriers with overlapping functions. Here we focus on two c-type cytochromes (cyt) in facultative phototrophic...Full Text Available
PrefaceCardiovascular effects of epoxyeicosatrienoic acids (EETs) include vasodilation, vascular smooth muscle cell anti-migratory actions, and anti-inflammatory actions. These...Full Text Available
Hypoxia, or reduced oxygen, occurs in a variety of clinical and environmental situations. Hypoxic exposure is associated with decreased muscle mass and a concomitant reduction in exercise capacity,...Full Text Available
Dimethyl sulfoxide (DMSO) is commonly used in biological studies to dissolve drugs and enzyme inhibitors with low solubility. While DMSO is generally thought of as being relatively inert, it...Full Text Available
An organ-specific invertase deficiency affecting only the primary root system is described in the Oh 43 inbred maize (Zea mays). Invertases (acid and neutral/soluble and insoluble)...Full Text Available
IntroductionWhile epidemiological methods have grown in sophistication during the 20th century, their application in historical occupational (and environmental) health...Full Text Available
In this paper method of constructing quasi-exactly solvable models of quantum mechanics is proposed. This method is based on the use of infinite-dimensional representations of simple and semi-simple Lie algebras.
Nitrate reduction was studied as a function of carbohydrate concentration in detached primary leaves of barley (Hordeum vulgare L. cv Numar) seedlings under aerobic conditions in light...Full Text Available
Enolase is a multifunctional enzyme that plays important roles in many biological and disease processes. α-Enolase from human liver (hENO1) was expressed as a soluble protein and purified by...Full Text Available
... starch amounts during somatic and zygotic embryogenesis of Acca sellowiana (Myrtaceae)Rosete Pescadora, Gilberto B. Kerbauyb, Jane E. ... Comparative analysis of zygotic and somatic embryogenesis of Acca ...
The extracellular domain of human fibroblast growth factor receptor (XC-FGF-R) was expressed in Escherichia coli. The protein was purified to homogeneity and the interaction with basic fibroblast growth...Full Text Available
The rejection thresholds of the blowfly Phormia regina Meigen for a selected series of substituted aliphatic hydrocarbons have been determined and an analysis made of the effect on...Full Text Available
Microorganisms are ubiquitous in subsurface environments although their populations sizes and metabolic activities can vary considerably depending on energy and nutrient inputs. As a result of their metabolic activities and the chemical properties of their cell surfaces and the exopolymers they produce, microorganisms can directly or indirectly facilitate the biotransformation of radionuclides, thus altering their solubility and overall fate and transport in the environment. Although biosorption to cell surfaces and exopolymers can be an important factor modifying the solubility of some radionuclides under specific conditions, oxidation state is often considered the single most important factor controlling their speciation and, therefore, environmental behavior.
A gelcasting composition has improved drying behavior, machinability and shelf life in the dried and unfired state. The composition includes an inorganic powder, solvent, monomer system soluble in the solvent, an initiator system for polymerizing the monomer system, and a plasticizer soluble in the solvent. Dispersants and other processing aides to control slurry properties can be added. The plasticizer imparts an ability to dry thick section parts, to store samples in the dried state without cracking under conditions of varying relative humidity, and to machine dry gelcast parts without cracking or chipping. A method of making gelcast parts is also disclosed.
The authors investigated phase equilibria in the system carbon dioxide-hexametapol. Vacuum-distilled solvent of ''pure'' grade was used. The solubility of CO/sub 2/ in hexametapol under pressures at various temperatures and the temperature dependence of the Henry's law coefficient is show. It is concluded that the solubility of carbon dioxide in hexametapol in the temperature and pressure ranges corresponding to the operating conditions of industrial equipment for removing CO/sub 2/ from gases conforms to the Krichevskii-II'inskaya equation. The experimental data can be used for equipment 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 salt ...
The Army Reactor Area (ARA) II was constructed in the late 1950s as a test site for the Stationary Low Power Reactor No. 1 (SL-1). The SL-1 was a prototype power and heat source developed for use at remote military bases using a direct cycle, boiling water, natural circulation reactor designed to operate at a thermal power of 3,000 kW. The ARA II compound encompassed 3 acres and was comprised of (a) the SL-1 Reactor Building, (b) eight support facilities, (c) 50,000-gallon raw water storage tank, (d) electrical substation, (e) aboveground 1,400-gallon heating oil tank, (f) underground 1,000-gallon hazardous waste storage tank, and (g) belowground power, sewer, and water systems. The reactor building was a cylindrical, aboveground facility, 39 ft in diameter and 48 ft high. The lower portion of the building contained the reactor pressure vessel surrounded by gravel shielding. Above the pressure vessel, ...
The hydration behavior of a number of square planar Pt(II) bis(cyano) complexes has been examined, and the limiting stoichiometries are related to the steric requirements of the dinitrogen bidentate ligands coordinated to the metal center. In particular, the IR, UV/vis, and [sup 1]H, [sup 13]C, and [sup 195]Pt NMR spectroscopic data for the compound Pt[sup II]dtbipy(CN)[sub 2] [dtbipy = 4,4[prime]-[l brace]C(CH[sub 3])[sub 3][r brace][sub 2]-2,2[prime]-bpy] have been determined and show that, at relative humidities (rh) above [approximately]40%, this complex sorbs five water molecules at room temperature. The sorption process consists of a rapid step in which one H[sub 2]O adds to the complex and which appears to be independent of rh, followed by a slower, rh-dependent step leading to the final stoichiometry. In contrast, the analogous 2,2[prime]-bpy complex sorbs no water under these conditions, while the ...
A large part of mechanical and durability characteristics of cement-based materials comes from the performances of the hydrated cement, cohesive matrix surrounding the granular skeleton. Experimental studies, in situ or in laboratory, associated to models, have notably enhanced knowledge on the cement material and led to adapted formulations to specific applications or particularly aggressive environments. Nevertheless, these models, developed for precise cases, do not permit to specifically conclude for other experimental conclusions. To extend its applicability domain, we propose a new evolutive approach, based on reactive transport expressed at the microstructure scale of the cement. In a general point of view, the evolution of the solid compounds of the cement matrix, by dissolutions or precipitations, during chemical aggressions can be related to the pore solution evolution, and this one relied to the ionic exchanges with the external environment. By the ...
Some biological effects of hypoglycin-A, a compound isolated from the fruit of Blighia sapida, have been investigated. Administration of this compound to animals caused drowsiness...Full Text Available
Data on the reactions of thiocyanogen and thiocyanogen halides with unsaturated compounds are systematised. The kinetic and stereo- and regiochemical regularities of these reactions are analysed. The bibliography includes 81 references.
Woolfolk, C. A. (University of Washington, Seattle). Reduction of inorganic compounds with molecular hydrogen by Micrococcus lactilyticus. II. Stoichiometry with inorganic...Full Text Available
The invention relates to a method for purifying a gas mixture containing at least one undesirable gas compound utilizing certain sulfonamide or sulfamide solvents.
The report contains general information on aluminium and aluminium compounds concerning the existing standards, emissions, exposure levels and effect levels. The document is to be considered as a first evaluation to be used for the national discussion dur...
The antibacterial activities of different nitroheterocyclic compounds were assessed by an agar dilution method against aerobic, microaerophilic, and anaerobic bacteria. Nitronaphthofurans inhibited...Full Text Available
In the present study, the authors examine the interactions of pentavalent technetium ions (TcO/sup 3+/) with the basic form of the lasalocid A in pure methanol solvent and in methanol-water mixtures. There are a number of reasons for such a study. First, the interactions of technetium ions with biologically important compounds are of considerable importance owing to the widespread use of /sup 99m/Tc in diagnostic radio-imaging. Second, lasalocid A is known to transport metal ions across phospholipid bilayer membranes and between the aqueous cores of phospholipid inverse micelles. Third, lasalocid A is known to bind and solubilize metal ions in bulk organic liquid phases. Fourth, the conformation adopted by lasalocid A on interaction with TcO/sup 3+/ appears to be different than those found in most other cases and circumstances. Fifth, it may also be possible to use the competition of TcO/sup 3+/ with other, physiologically relevant cations ...
A technique of producing radioactive isotopes of rare earth elements (r.e.e.) and carrier free "2"4"2Am is suggested. The technique makes use of ''sandwich'' phthalocya=- nine complexes of r.e.e. and americium placed on sorbent. This is a new type of r.e.e. compounds and actinides (C_3_2H_1_6N_8)_2M (M is a metal ion) which are thermally, radiationally and chemically stable, dissolve well in some organic solvents and do not dissolve in water. Radiation and chemically stable activated carbon is used as a sorbent carrier. After irradiation the target is treated by a weakly acid solution or complex-former solution. Radioactive atoms formed due to (n, #gamma#)-reaction and desoleting the complex because of recoil transfer into the solution. When irradiating in the flux of 10"1"3 neutr./cm"2 x s for 1 hour it is possible to produce radioactive isotopes with the yield from 20 to 90%, for example "1"6"0Tb, "1"6"6Ho with enrichment factor > 100 and ...
As part of their corporate policy on environmental protection, Chevron, has taken an approach to work collaboratively with other industry members, universities and government agencies in phytoremediation research. The petroleum industry is interested in the integration of phytoremediation with the many biotechnology treatment technologies currently being used by the industry. Phytoremediation is a complex technology that does not just transfer wastes to another site, but offers in-situ final use and disposal treatment at sites anywhere in the world. Sites for potential remediation range from abandoned large refineries, chemical plants, or small urban gas stations. Research has focused on the cleanup of metals and hydrocarbons in diverse types of soil, water and groundwater conditions. This includes research into remediation of petroleum contaminants such as total petroleum hydrocarbon (TPH), polynuclear aromatic hydrocarbons as well as benzene in soil and the ...
Results from three separate experiments that have some relevance to bound residues are reported. In the first, "1"4C-labelled paraquat was lost when applied to soil in the field, about 26% of the radioactivity disappearing in 15 months, whereas in laboratory incubation studies there was no loss of radioactivity in one year. Two possible explanations are (i) that there was photolytic decomposition in the field, (ii) the preparation of the soil for the laboratory study upset the microbial ecology of the soil to the detriment of organisms that can degrade paraquat. In an experiment with "1"4C-labelled isoproturon, there was an indication that there was slightly more "1"4C in the unextractable humin fraction in soil in which wheat plants were grown than in bare soil. Work in the UK, Federal Republic of Germany and in Switzerland has shown that the phytotoxicity of residues of atrazine, carbetamide, chloridazone, propyzamide, simazine, lenacil, monolinuron, linuron, propachlor 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 ...
ObjectivesThe overall objective of the proposal is to test the conclusions reached in a recent article by Magnani, Mencuccini et al (2007), in which we proposed for the first time that the Net Ecosystem Productivity (NEP) of forests of the temperate and boreal region does not depend on temperature or rainfall but, rather, on nitrogen deposition (Ndep) from the atmosphere. It is widely accepted that Ndep can increase forest C sequestration, however the results from our 2007 paper reported a sensitivity dC/ [continued...]DescriptionCombustion of fossil fuels and use of fertilisers in agriculture has increased the amount of nitrogen compounds present in the atmosphere and the biosphere. More atmospheric nitrogen is converted into reactive nitrogen by anthropogenic activities than by all natural processes combined. This phenomenal historical increase in nitrogen deposition is responsible for several serious environmental problems, such as soil acidification and ...
Recent organic geochemical studies differ radically in their interpretation of the origin of the Gulf coast oils. However all studies since (and including) Thompson, et al. 1989, emphasize the considerable geographic variation in genetic oil types and are in generalized agreement as to the genetic oil types present and their spatial and stratigraphic relationships. In particular it is accepted that the Gulf rim (both north and south) is encircled by a ring of Mesozoic carbonate-sourced oils and that there is also at least one major deep water trend of carbonate-sourced oils in the northern Gulf. It is also generally agreed that many of the Gulf rim oils are of Oxfordian-Kimmeridgian age, though some, like the Sunniland oils of Florida, are of lower Cretaceous origin. Major disagreement still occurs over the sources of the Louisiana offshore oils and onshore Wilcox reservoired oils. One {open_quotes}school of thought{close_quotes} assigns all these oils to Mesozoic ...
New comparative tests on two different types of solar collectors are presented in this paper. A standard glazed flat plate collector and an evacuated tube collector are installed in parallel and tested at the same working conditions; the evacuated collector is a direct flow through type with external compound parabolic concentrator (CPC) reflectors. Efficiency in steady-state and quasi-dynamic conditions is measured following the standard and it is compared with the input/output curves measured for the whole day. The first purpose of the present work is the comparison of results in steady-state and quasi-dynamic test methods both for flat plate and evacuated tube collectors. Besides this, the objective is to characterize and to compare the daily energy performance of these two types of collectors. An effective mean for describing and analyzing the daily performance is the so called input/output diagram, in which the collected solar energy is plotted against the ...
The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after the drying process. Losses of nitrogen were ...
In the MnIII complex of the title compound, [MnIII(C18H12N4O2)(H2O)2]ClO4, the MnIII atom is coordinated by four N atoms from the bpb2- [1,2-bis(pyridine-2-carboxamido)benzene] ligand located in the equatorial plane and two O atoms of water molecules at axial positions, yielding a distorted MnN4O2 octahedral coordination geometry. The bpb2- ligand is nearly planar, with a maximum deviation of 0.2311 (3) A from the mean plane. The MnIII complex cation and the perchlorate anion, both of which are located on twofold rotation axes, are connected by O-H...O and C-H...O hydrogen bonds into a three-dimensional supramolecular network structure.
Summary Reactive extrusion was utilised for starch/poly(butylene adipate co-terephthalate) (PBAT) blown film production, using maleic anhydride (MA) and citric acid (CA), alone or combined, as compatibilisers. These compounds (2% w/w) were added to the starch/PBAT (55:45) mixture after dispersion on glycerol. More rigid films, with greater tensile strength (9.82--0.45-MPa), were produced when 2.0% CA was used. The opposite, little homogeneity and poor tensile strength (0.77--0.12-MPa) and elongation (2.67--0.67%) were found in films produced using 2.0% MA. Barrier properties to water vapour were improved by compatibilisers. FTIR analysis showed that CA and MA were able to promote esterification/transesterification reactions. Blends containing CA also showed better phase compatibilisation i...
In the course of observing by means of Auger spectroscopy graphite gasification reactions catalyzed by metals, it has been found that in the presence of hydrogen, nickel appears to diffuse from the surface into the bulk of the graphite. When potassium is deposited on graphite, it is volatilized above 400/sup 0/C. Surprisingly the production of methane and carbon dioxide from the reaction of graphite and steam was catalyzed by potassium at as low a temperature as 250/sup 0/C. It has been shown that literature on the alkylation of benzene with synthesis gas is erroneous and that the products reported are due to Lewis acid catalyzed cracking of benzene. A novel cobalt mediated, reversible cleavage of a vinyl-hydrogen bond has been discovered. All products from the thermal decomposition of tetralin have been identified. The stereochemistry of cis-1, 2 dihydrotetralin was determined. In the utilization of the water gas shift reaction as a reducing agent for model coal ...
The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and ...
Ex situ and in situ fuel cell degradation of a sPAEK membrane were investigated. Post-mortem analyses of the aged membrane and of the degradation products eluted in water were carried out by NMR, IR, SEC and EDX. Ex situ agings were performed in a low concentration H{sub 2}O{sub 2} solution (0.07%) without any metallic catalyst. We exemplify that ex situ accelerated aging tests in such hydrogen peroxide solution are relevant to the chemical degradation in fuel cell. We have shown that a 500 h fuel cell test at moderate temperature (60 C) induces significant modifications on the macromolecules such as a 40% molecular weight reduction. Degradation appears heterogeneous and limited to the cathode side. The model compound approach developed in the previous article (Perrot et al.) has allowed the identification of the aging path in fuel cell. Phenolic and carboxylic acid chain ends have been identified as the main products resulting from polymer ...
Three abiotic systems are described that catalyze the reductive dehalogenation of heavily halogenated environmental pollutants, including carbon tetrachloride, trichloroethene, and perchloroethene. These systems include (a) an electrolytic reactor in which the potential on the working electrode (cathode) is fixed by using a potentiostat, (b) a light-driven system consisting of a semiconductor and (covalently attached) macrocycle that can accept light transmitted via an optical fiber, and a light-driven, two-solvent (isopropanol/acetone) system that promotes dehalogenation reactions via an unknown mechanism. Each is capable of accelerating reductive dehalogenation reactions to very high rates under laboratory conditions. Typically, millimolar concentrations of aqueous-phase targets can be dehalogenated in minutes to hours. The description of each system includes the elements of reaction mechanism (to the extent known), typical kinetic data, and a discussion of the feasibility of ...
Proposed is a lubricating composition for processing flushing fluids, which contains synthetic fatty acids of the fraction carbon 11-20, oxidized petrolatum, mineral oil, and additives. In order to increase the antiwear, anticorrosion, and antiscratching properties of the composition under conditions of polymineral corrosion with simultaneous decrease in the water loss of the flushing fluids as additives the composition contains stearic acid, polyoxyethylated methyl phenol, naptha soap, 1,5-dibenzoylnapthaline-4', 4''-dicarboxylic acid, calcined soda, secondary nonsaponifiables, obtained in the production of synthetic fatty acids by oxidation of paraffin, and polyfunctional oxygen-bearing compounds, obtained by oxidation of secondary nonsaponifiables by atmospheric oxygen, with the following ratio of components, wt%: 17.2-19.2% synthetic fatty acids of the carbon 17-20 fraction, 5.2-5.8% oxidized petrolatum, 3.5-3.7% ...
Fuel rod failures produce a release of fission products into primary coolant system. Since nuclear power plants have licensing limits for the release of volatile fission products to the environment (off-gas limits) detailed monitoring of the development of clad failure is necessary. In case of fuel rod failure a release of fission products into the primary coolant system arises. Fission gases accumulated in the free volume of a fuel rod escape through the clad defect. Water entering the fuel rod reacts with fission products, forming volatile chemical compounds. These may escape in a similar manner into the fission gases. Other compounds may dissolve and may be carried outside the fuel rod as dissolved species. Consequently, the distribution of these fission products, in the cross section of the fuel rod, is modified. An implementation of the maximum entropy gamma computed tomography technique is used to obtain such ...
A small-sized inexpensive carbon dioxide gassensor was prepared using LiTi2 (PO4)3 +0.2Li3PO4 as lithium-ion conductive, solid electrolyte and its detectability and the effects of co-existing gases were examined. The above compound was obtained by the method where a powdery mixture of Li2CO3, TiO2, (NH4)H2PO4 and Li3PO3 was molded in the presence of a sintering assistant, subjected to hydrostatic press, and sintered. Measurements were made on the relation between CO2 concentration and the electromotive force of the CO2 sensor made of the compound and the influence of concentration of coexisting NO2, SO2 or CH4 on the electromotive force. The results are summarized as follows. A linear relation exists between the electromotive force and the CO2 concentration in the range from 80ppm to 1% to show a good agreement between theoretical and experimental results. Coexistence of NO2 the range of 100-4500ppm has no influence on the electromotive force. ...
The partial oxidation of 1,3-butadiene has been investigated over VMoO catalysts synthesized by sol-gel techniques. Surface areas were 9-14 m{sup 2}/g, and compositions were within the solid solution regime, i.e. below 15.0 mol % MoO{sub 3}/(MoO{sub 3} + V{sub 2}O{sub 5}). Laser Raman Spectroscopy and XRD data indicated that solid solutions were formed, and pre- and post-reaction XPS data indicated that catalyst surfaces contained some V{sup +4} and were further reduced in 1,3-butadiene oxidation. A reaction pathway for 1,3-butadiene partial oxidation to maleic anhydride was shown to involve intermediates such as 3,4-epoxy-1-butene, crotonaldehyde, furan, and 2-butene-1,4-dial. The addition of water to the reaction stream substantially increased catalyst activity and improved selectivity to crotonaldehyde and furan at specific reaction temperatures. At higher water addition concentrations, furan selectivity increased from 12% to over 25%. The ...
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Finland has some 10 million hectares of peatland, accounting for almost a third of its total area. Macroclimatic conditions have varied in the course of the Holocene growth and development of this peatland, and with them the habitats of the peat-forming plants. Temperatures and moisture conditions have played a significant role in determining the dominant species of mire plants growing there at any particular time, the resulting mire types and the accumulation and deposition of plant remains to form the peat. While in a natural state the mires of Finland have functioned as carbon dioxide sinks throughout the post-glacial period, but the ditching of peatland for forestry and agriculture, amounting to some 5,7 million hectares in Finland, has affected their water balance, especially over the last hundred years, and has thereby altered the quantity and species composition of the mire vegetation. The invasion of trees and woody plants to replace the typical mire plants ...
A Multi-Channel Algebraic Scattering (MCAS) theory is presented with which the properties of a compound nucleus are found from a coupled-channel problem. The method defines both the bound states and resonances of the compound nucleus, even if the compound nucleus is particle unstable. All resonances of the system are found no matter how weak and/or narrow. Spectra of mass-7 nuclei and of {}^{15}F, and MCAS results for a radiative capture cross section are presented.
Our studies on K#beta#/K#alpha# X-ray intensity ratios of some of the technologically important 3d-transition metal compounds have been reviewed. Comparison of the experimental results with single-configuration Dirac-Fock calculations provided important information on the valence states of the transition metals in various compounds, which can be helpful in understanding the nature of bonding in the compounds. (author)
...contributions from the following fields: Catalytic elimination of environmental pollutants, such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, ...contributions from the following fields: Catalytic elimination of environmental pollutants, such as nitrogen oxides, carbon monoxide, sulfur compounds, chlorinated and other organic compounds, ...
The objective of this project was to develop new photocatalytic or other innovative process chemistry for the treatment of pink water and related contaminated water.
The magnetic scattering spectra of RAgSb_2 (R = Ho, Er, Tm) intermetallic compounds are measured and their crystal electric field parameters are determined using inelastic neutron scattering. It is revealed that the ground state is a nonmagnetic singlet for the HoAgSb_2 compound, a Kramers doublet with a strongly anisotropic g factor for the ErAgSb_2 compound, and a quasi-doublet (random doublet) characterized by an extremely anisotropic g factor for the TmAgSb_2 compound. The exchange interaction is estimated in the molecular field approximation. The magnetic properties of the RAgSb_2 compounds are analyzed in terms of the energy level schemes and eigenfunctions determined in this study. The calculated anisotropic magnetic susceptibilities for all compounds are in good agreement with the experimental data obtained for single crystals.
Aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), a sterically hindered amine, was examined as a potential CO{sub 2} absorbent and compared with the most commonly used absorbent, monoethanolamine (MEA) solution, through equilibrium solubility measurements and {sup 13}C NMR spectroscopic analyses. The solubilities of CO{sub 2} in aqueous 10 mass % AHPD solutions were higher than those in aqueous 10 mass% MEA solutions above 4 kPa at 298.15 K, but lower below 4 kPa. The solubility difference between these two solutions increased with the CO{sub 2} partial pressures above the crossover pressure. Equilibrated CO{sub 2}-MEA-H{sub 2}O and CO{sub 2}-AHPD-H{sub 2} solutions at various CO{sub 2} partial pressures ranging from 0.01 to 3000 kPa were analyzed by {sup 13}C NMR spectroscopy. AHPD contains more hydroxyl groups than nonhindered MEA, and hence the chemical shifts in its {sup 13}C NMR spectra were strongly ...
In order to obtain knowledge about formation and growth of condensed ring structure in a coalification process, discussions were given on product skeleton structure by using hydrogenation and hydrocracking of heated cellulose. In underwater heating of cellulose, reaction of dehydration has occurred at 200{degree}C or lower, that of decarbonation at 250{degree}C or higher, and that of demethanizing at 300{degree}C, resulting in production of a dark-brown coal-like substance. The substance has lower H/C value and higher O/C value than coal. As the underwater heating temperature rises, the hydrogenation reactivity of the heated substance decreases, and so does the ratio of conversion into toluene solubles. These phenomena are related to strength of cross-linking bond between unit skeleton structures. A substance heated at an underwater heating temperature of 200{degree}C turns toluene-soluble almost completely even during the hydrogenation ...
Metalloid cluster compounds of group 14 of the general formulae EnRm with n > m (E = Si, Ge, Sn, Pb; R = ligand), where naked as well as ligand bound tetrel atoms are present, represent a novel class of cluster compounds in group 14 chemistry and can be seen as intermediates on the way to the elemental state. Therefore, interesting properties are expected for these compounds, which might complement results from nanotechnology. In this article, first results for germanium are discussed, together with novel build-up reactions on the way to novel materials based on metalloid cluster compounds. GRAPHICAL ABSTRACT[image omitted
A reaction of aqueous-methanol solutions of thiocarbazide and salycilic aldehyde, taken in a molal ratio of 1:2 on the matrix of oxovanadium(VO) in the presence of aqueous ammonium results in a coordination compound of the VC_1_5H_1_2N_4O_3S composition. Similar compounds are obtained with salts of nickel(2) and copper(2). Complexes of oxovanadium(4) and copper(2) have effective magnetic moments normal for systems with a spin of 1/2. The compound with nickel is diamagnetic. These data agree with the configuration of the coordination compounds obtained.
The number of reports concerning the chemical toxicology of metals which are released in the environment by natural as well as anthropogenic sources, have been increasing constantly. Lead, cadmium, and manganese have found a variety of uses in industry, craft, and agriculture owing to their physical and chemical properties. The environmental burden of heavy metals has been rising substantially by smelter emission in air and waste sewage in water. Further, organic compounds of lead and manganese used as antiknock substances in gasoline are emitted into the atmosphere by automobile exhaustion. Such environmental contamination of air, water, soil, and food is a serious threat to all living kinds. Although these metals are known to produce their toxic effects on a variety of body systems, much emphasis has been placed on their effects on the nervous system owing to apparent association of relatively low or ...
Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ...
Volume 2 of the water resources data for the 1992 water year for Oklahoma consists of record of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes or reservoirs; and water levels of ground-water well. The report contains discharge records for 136 gaging stations; stage and contents for 31 lakes or reservoirs; water quality for 50 gaging stations. Also included are 61 partial-record or miscellaneous streamflow stations and 28 ground-water sites.
The behavior and properties of associated bodies were studied through measurement of surface tension considering acetone-soluble fraction relatively light among various solvent extracts of coal. In experiment, the acetone-soluble fraction was extracted from the substances extracted from Upper Freeport coal as standard specimen using the mixed solvent of carbon disulfide (CS2) and N-methyl-2-pyrrolidinone (NMP), and it was dissolved into NMP after drying. Surface tension was measured by Wilhelmy method. The experimental results are as follows. Equilibrium surface tension is equal to the surface tension of pure solvent in a low concentration range of solution, and decreases with an increase in concentration approaching a fixed value at 0 in log concentration, nearly showing an S curve. Adsorption of species with non-polar aromatic ring of the acetone-soluble fraction on a solution surface probably decreases surface tension. ...
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 ...
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 temperatures of ...
The purpose of this communication is to determine whether the solubility enhancements for cold-worked Pd-Ni alloys increase or decrease with atom fraction of Ni. Substitutional Ni atoms contract and Pd lattice, in contrast to the lattice expansion resulting from substitutional Ag in Pd. The Pd-Ni alloy system forms a continuous series of fcc solid solution alloys over the whole composition range. The solubility enhancements will also be determined for a series of homogeneous, ternary Pd[sub 1[minus]x]Ni[sub 1/2x]Ag[sub 1/2x] alloys for x in the range from 0 to 0.2. For this series of ternary alloys the fcc lattice parameters do not change significantly from that of pure Pd. The alloys used in this research were purchased from Tanaka Kikinzoku Kogyo K.K. The detailed experimental procedure has been described previously. The alloys were all deformed by cold-rolling ca 90%. Both the binary and ternary alloys showed only single sets of fcc lattice ...
Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. PEG 300 was found to be the best solvent in this study and shows ...
The soluble pool of alpha hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, beta A hemoglobin chain labeled with ["3H]N-ethylmaleimide. This pool of soluble alpha chains was 0.067 #+-# 0.017% of hemoglobin in blood of normal adult, 0.11 #+-# 0.03% in heterozygous beta thalassemia and ranged from 0.26 to 1.30% in homozygous beta thalassemia intermedia. This elevated pool of soluble alpha chains observed in human beta thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% in the most dense red blood cells. The amount of insoluble alpha chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In beta thalassemia intermedia the amount of insoluble alpha chains was correlated with the decreased spectrin content of red cell membrane and was associated with a decrease in ...
This work describes a three-step pre-treatment route for processing spent commercial Ni Mo/Al_2O_3 catalysts. Extraction of soluble coke with n-hexane and/or leaching of foulant elements with oxalic acid were performed before burning insoluble coke under air. Oxidized catalysts were leached with 9 mol L"-"1 sulfuric acid. Iron was the only foulant element partially leached by oxalic acid. The amount of insoluble matter in sulfuric acid was drastically reduced when iron and/or soluble coke were previously removed. Losses of active phase metals (Ni, Mo) during leaching with oxalic acid were compensated by the increase of their recovery in the sulfuric acid leachate. (author)
Soluble starch?based biodegradable and microporous microspheres (SDM-Ms) were prepared by emulsion chemical cross-linking technique using trisodium trimetaphosphate (TSTP) as the cross-linker. The resultant amorphous SDM-Ms were excellently identified by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The internal rupture and surface-controlled erosion were the predominant degradation mechanisms for SDM-Ms. The obtained SDM-Ms were applied to adsorb coix seed oil (CSO) by immersing method. The adsorption capacity of CSO within SDM-Ms was determined, namely 0.5238?g/g, and the thermal stability was shown higher than that of the free CSO. A burst release appeared in the second hour, followed by controlled release. Diffusion, d...
Soluble TWEAK is a member of the TNF-alpha family of cytokines that has been shown to predict mortality in patients with heart failure. Pulmonary artery hypertension is a devastating disease, in which right ventricular function has been shown to be the major determinant of prognosis. In this hypothesis-generating study, we sought to evaluate the potential usefulness of sTWEAK in the prediction of disease severity in patients with pulmonary artery hypertension. We therefore conducted a retrospective analysis of sTWEAK serum levels in 95 stable patients with PAH. For all patients data on hemodynamic parameters, biomarkers and functional exercise tests were available. Compared to controls, patients with PAH showed significantly decreased levels of sTWEAK [median 314?pg/ml (interquartile range...
We report the fabrication of p"+/n junctions using Ge"+, C"+, and B"+ co-implantation and a spike anneal. The best junction exhibits a depth of 26 nm, vertical abruptness of 3 nm/decade, and sheet resistance of 520 Ohm/square. The junction location is defined by where the boron concentration drops to 10"1"8 cm"-"3. These junctions are close to the International Technology Roadmap specifications for the 65 nm technology node and are achieved by careful engineering of amorphization, stresses, and point defects. Advanced simulation of boron diffusion is used to understand and optimize the process window. The simulations show that the optimum process completely suppresses the transient-enhanced diffusion of boron and the formation of boron-interstitial clusters. This increases the boron solubility to 20% above the equilibrium solid-state solubility.
Starch from the fruits of sweetsop (Anonna squamosa) and soursop (Anonna muricata) were isolated and purified and the fat, ash, phosphorus and protein contents measured. The amount of amylose present was determined spectrophotometrically and found to be very similar (19%) for both starches. Scanning electron microscopy showed very small indented and spherical granules from both with an average granule size of 4.84mm and 4.72mm, respectively. The physicochemical properties, namely the swelling power, solubility, pasting characteristics, paste clarity and freeze-thaw stability were studied to assess the functionality of the starch pastes as hydrocolloids. The sweetsop starch showed higher swelling power and solubility compared to soursop starch and had a lower gelatinization temperature indi...
The corrosion resistance of molybdenum, molybdenum disilicide, and a SiC_(_p_)/Al_2O_3 composite to molten E-glass at 1,550 C was studied. Mo showed no tendency to oxidize as it was immersed in soda-lime silicate glass in a parallel study. MoSi_2 was corroded by soluble molecular oxygen, leaving a Mo_5Si_3 interface behind. The SiC_(_p_)/Al_2O_3 composite was corroded at a more rapid rate wherein the SiC component was oxidized to form amorphous silica and CO bubbles. Based on these results, the activity of soluble molecular oxygen in E-glass was determined to be in the range of 2.4 x 10"-"1"4 to 2.0 x 10 "-"8.
Energy from biomass is a CO{sub 2} neutral, sustainable form of energy. Anaerobic digestion is an established technology for converting biomass to biogas, which contains around 60% methane, besides CO{sub 2} and various contaminants. Most types of biomass contain material that cannot be digested; in woody biomass, this portion is particularly high. Therefore, conventional anaerobic digestion is not suited for the production of biogas from woody biomass. While wood is already being converted to energy by conventional thermal methods (gasification with subsequent methanation), dung, manure, and sewage sludge represent types of biomass whose energy potential remains largely untapped (present energetic use of manure in Switzerland: 0.4%). Conventional gas phase processes suffer from a low efficiency due to the high water content of the feed (enthalpy of vaporization). An alternative technology is the hydrothermal gasification: the water contained ...
The transport of radon in concrete takes place through the complicated network of interconnected pores that is, at any time, the result of the process of hydration of cement and of moisture distribution and transport. Initially the microstructure of concrete depends on the mix proportions and curing conditions, its time-evolution being conditioned by its surrounding environment. Radon transport will be consequently a function of time, as it is influenced by the changing microstructure (total porosity and its distribution) and by the amount and distribution of the moisture contained in the pore system. A selection of information from the large amount of literature available on concrete is presented in chapter 2. A model that describes the process of hydration, of microstructure development and of moisture transport is presented in chapter 3. The physics of radon diffusion in homogeneous porous materials is outlined in chapter 4. The coupling of the numerical implementation of the ...
The transport of radon in concrete takes place through the complicated network of interconnected pores that is, at any time, the result of the process of hydration of cement and of moisture distribution and transport. Initially the microstructure of concrete depends on the mix proportions and curing conditions, its time-evolution being conditioned by its surrounding environment. Radon transport will be consequently a function of time, as it is influenced by the changing microstructure (total porosity and its distribution) and by the amount and distribution of the moisture contained in the pore system. A selection of information from the large amount of literature available on concrete is presented in chapter 2. A model that describes the process of hydration, of microstructure development and of moisture transport is presented in chapter 3. The physics of radon diffusion in homogeneous porous materials is outlined in chapter 4. The coupling of the numerical implementation of the ...
Polychlorinated dibenzo-p-dioxins and dibenzo-furans form a family of more than 200 compounds which are relatively stable in the biosphere and tend to accumulate in the human body. The tetra- to hexa-chlorinated dioxins and furans are considered highly toxic. To facilitate the assessment of the total toxicity of dioxin and furan mixtures, the estimated toxic effects of the individual compounds relative to the 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) were introduced as Toxic Equivalent Factors which yield, when multiplied with the respective concentrations, the Toxic Equivalent (TE) of the mixture. Toxic dioxins and furans are unintentionally formed in a number of industrial combustion processes such as waste incineration and iron ore sintering, in the chemical industry and in household heating. To keep the emissions as low as possible, off-gas clearing systems for the collection of dioxins and furans are increasingly prescribed by the ...
ObjectivesObjectives Not AvailableDescriptionA collaborative study of the anaerobic treatment of wastes containing recalcitrant and inhibitory compounds using the SERC Anaerobic facility, in particular biomass structure, monitoring and control, catabolism and toxicity, pre-acidification and microbial growth and mesophilic and thermophilic lignocellulose degradation.~%~
Superconductivity in A-15 compounds is examined in terms of electron pairing induced by exchange of acoustic plasmons. The electronic band structure of Nb_3Sn, V_3Si, and similar materials favor transition temperatures of Tsub(c)approximately20 K. (Auth.).
This report will be revised upon completion of current testing investigating the radiolytic stability of additional energetic materials and the analysis of tank farm samples for volatile and semi-volatile organic compounds.
We describe an Ebolavirus minigenome-based system that is suitable for high-throughput screening of compounds able to impair Ebolavirus virus replication and/or transcription....Full Text Available
The present invention relates to a method of acidizing a subterranean formation or well bore employing an acidic solution containing a corrosion inhibitor composition comprising an inhibiting effective amount of an acetylenic alcohol, a quaternary ammonium compound, an aromatic hydrocarbon and an antimony compound.
The OH-initiated photo-oxidation of n-butane was used as a source of 1- and 2-butoxy radicals. Reactions producing ketones and other organic compounds are explained. Rates of photolysis were determined and are discussed.
Iron is a central element in the metabolism of normal and malignant cells. Abnormalities in iron and ferritin expression have been observed in many types of cancer. Interest in characterizing iron compounds...Full Text Available
Although cross-resistance in houseflies to the organophosphates has eliminated numerous potentially useful compounds from field use, the ”subgroup” specificity of this phenomenon has...Full Text Available
A brief review is given of the nature of lattice instabilities in high-T/sub c/ superconductors. The Frohlich instability in A-15 compounds is indicated to be a microdomain which acts as an embryo for the Martensitic transformations in these compounds.
Microbial degradation of aromatic hydrocarbons has been studied with the aim of developing applications for the removal of toxic compounds. Efforts have been directed toward the genetic manipulation...Full Text Available
K_#beta#/ K_#alpha# x-ray intensity ratio of chromium were measured in different chromium compounds. The results show the variation of the intensity ratio as a function of the chemical environment around the metal ion. (author)
GR99060 and GR99062 are representatives of a series of 1,2,4-triazino[5,6-b]indole compounds. This series possessed broad-spectrum antifungal activity in vitro. The MIC ranges of the two compounds were...Full Text Available
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.
From Toki-shakuyaku-san, an herbal formulation for “cleansing stagnated blood,” a key gene regulatory compound was purified and identified through a screening based on DNA microarray...Full Text Available
SC-CO/sub 2/ extraction of oil from peanuts is an alternative to hexane extraction or the mechanical oil press. Oil was successfully extracted using SC-CO/sub 2/ at temperatures of 25-120/sup 0/C and pressures of 140 -690 Bar. Pressure, temperature and particle size affected the extraction of oil. In the range studied, the highest values of temperature and pressure gave highest solubilities.
A soluble enzyme system from suspension cultures of Acer pseudoplatanus L. converts d-glucose 6-phosphate to myoinositol. A Mg2+-dependent phosphatase, present in...Full Text Available
The possibility of modifying the functional composition of humic acids by gas-phase ozonation of bed-oxidized brown coal was examined. About 90% of the organic matter of brown coal was converted to low-molecular weight soluble oxygen-containing products by stepwise liquid-phase ozonation (in chloroform and acetic acid).
A hydrocarbon composition having a major portion of a hydrocarbon preferably a lubricating oil such as mineral oil and at least a friction-reducing amount usually 0.01 to 10 weight percent of an amine or amine derivative of a hydrocarbon-soluble polymerized fatty acid e.g. a dimeramine derived from a dicarboxylic acid containing at least 12 carbon atoms such as 9(10)-carboxy stearic acid has improved antifriction and flue economy properties.
Wax appearance temperature (WAT) of three petroleum waxes in different solvent systems under varying thermal conditions has been determined. It is observed that this temperature mainly is a function of the concentration of the wax and the solubility parameter ([delta]) of the solvent taken. This dependence of WAT has been quantified in terms of these variables in the form of mathematical equation and nomographs. (orig.)
Detached first leaves of 3-day-old corn seedlings (Zea mays L. W64AxW183E) were incubated with nitrate in air or 100% O2 in the light. Nitrate accumulation in the leaves...Full Text Available
The kinetics of the reaction of zirconium phosphates with carbon tetrachloride in sodium and potassium chloride melt as well as the effect of temperature, gas flow, solubility and weight of the solid phase of the phosphate, and stirring of the melt on the chlorination rate has been studied. The kinetic parameters of the reaction (rate constants, activation energy, etc.) have been calculated.
sFlt-1 (soluble Flt-1) potently inhibits angiogenesis by binding extracellularly to VEGF (vascular endothelial growth factor). In the present paper, we report that hypoxia down-regulates sFlt-1 expression...Full Text Available
We study a variant of the Penner-Distler-Vafa model, proposed as a c = 1 quantum gravity: quenched' matrix model with logarithmic potential. The model is exactly soluble, and exhibits a two-cut branching as observed in multicritical unitary matrix models and multicut Hermitian matrix models. Using analytic continuation of the power in the conventional polynomial potential, we also show that both the Penner-Distler-Vafa model and our quenched' matrix model satisfy Virasoro algebra constraints.
... The Effect of the Temperature to Which the Material is Heated on the Process of Formation of Intermetallic Compounds in Magnetic Pulse Welding,. ...
The objectives of this project were to develop feasible synthetic routes to produce (1) 4(4{prime}-hydroxy-5{prime}6{prime},7{prime}8{prime}-tetrahydro-1{prime}-naphthylmethyl)-6-methyldibenzothiophene, and (2) a 1-hydroxynaphthalene-dibenzothiophene polymer. These compounds are thought to be representative of sulfur containing molecules in coal. The program was divided into two technical tasks. Unfortunately, the attempted syntheses of these compounds was unsuccessful due to their unusual reactivities. Attempted synthetic routes and possible future routes are described, and Appendix A lists the compounds that were synthesized during this program.
The phenomenon of time resonances (or explosions) can explain the exponential reduction of the energy, which is accompanied for the certain degree by slight fluctuations under some conditions in the range of the energy strongly overlapped compound-resonances. These resonant explosions correspond to formation of several highly-exited non-exponentially decaying nuclear clots (partial compound nuclei consisting of several small groups of projectile nucleons and targets). This paper is a continuation and expansion of theoretical authors' work, which is a more general self-consistent version of the time-evolution approach in comparison with the traditional Izumo-Araseki time compound-nucleus model.
Abstract Silicates are one of the most important classes of compounds on this planet, and more than 1000 silicates have been identified in the mineral kingdom. Additionally, several hundreds of artificial silicates have been synthesized. The substitution of oxygen by nitrogen leads to the structurally diverse and manifold class of nitridosilicates. Silicon nitride, one of the most important non-oxidic ceramic materials, is the binary parent compound of nitridosilicates, and it symbolizes the inherent material properties of these refractory compounds. However, prior to the last decades, a broad systematic investigation of nitridosilicates had not been accomplished. In the meantime, these and related compounds have reached a remarkable level of industrial application. This review illustrates...
The magnetic susceptibility of the ternary compounds, RPd_2Si_2 (where R=Gd, Tb, Dy, Ho and Er) has been measured. GdPd_2Si_2 and TbPd_2Si_2 order antiferromagnetically at 13 and 20 K respectively; the rest of the compounds do not show clear ordering down to 4.2 K. Palladium carries no moment in these compounds. The De Gennes formula is not obeyed indicating that the exchange interaction between the 4f moments via conduction electrons is not isotropic. (orig.).
Pilot industrial-scale testing of TSK-25 and TSK-10 compounds produced by NPP Tekhmet has been performed at Ruspolimet for siphon casting of 0.7?1.5-metric-ton ingots which are broader on the top (?flowers??) used for production of all-rolled rings; this is as an alternative to the existing process of pouring the steel into molds lubricated with petrolatum. The evaluation tests led to recommendation of the TSK-10 compound for industrial-scale testing; use of this compound enabled the petrolatum-lubricated steel casting process to be abandoned, thereby improving working conditions, and reducing rejects of the all-rolled ring products.
In the case of inelastic scattering of alpha particles to the 3"+ state, the averaged angular distributions show a characteristic shape, corresponding to the excitation of such an unnatural parity state by alpha particles in the compound nucleus process. The modified Hauser-Feshbach cross-section calculations give a good description of the averaged distributions for the alpha particle scattering to the 3"+ state and the compound nucleus parameters could be extracted. The calculations of the compounds nucleus contributions to the other states in the case of 24 MeV alpha particle scattering from "2"8Si show that this contribution is not negligible and in the case of the scattering to the 4"+ state seems to be dominant. (Z.M.).
Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L{sub {gamma}1} X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L{sub {gamma}1}/L{sub {beta}1} X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).
Chemical effects of L X-ray intensity ratios in niobium and molybdenum compounds were studied by electron and proton bombardments. L_#gamma#_1 X-rays which involve transition of 4d electrons of the valence shell were found to be sensitive to the chemical environment. The L_#gamma#_1/L_#beta#_1 X-ray intensity ratio increased with an increase of the 4d electron occupation of niobium or molybdenum in niobium or molybdenum compounds, showing that the chemical effects can be ascribed to the 4d electron behavior of the metallic atom in its compounds. (orig.).
... Abstract : The inherent brittleness of the A-15 compounds, and the requirement for a filamentary morphology, led to a heavy reliance on a powder ...
Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula
Certain radioiodine containing amides useful as brain imaging agents are disclosed. The compounds of the subject invention are represented by the formula.
Nitrogens, Sulfurs, Isotopes, and Hydrocarbons Gases Elements Ions and Inorganic Acids Organic Compounds Co-eluting Organics Hopanes, Cholestanes, and Sterols Pesticides,...
The completed ribbon-winding theory, including temperature loading of the high-pressure compound vessel, was proposed. The influence of the bending stress in the wound ribbon is taken into account. Internal core of the compound vessel consists of matrix and ring, made of different materials. The relations were derived in analytical form, describing the radial distribution of necessary tangential prestressing.
Based on the activation theory of alkali and sulfate, the influence of compound admixtures on the properties of high-content slag cement was studied by testing the strength, pore structure, hydrates, and microstructure, Test results show that compound admixtures can obviously improve the properties of high-content slag cement. The emphasis of the present research is two-fold: substituting gypsum with anhydrite and calcining gypsum. These both can improve early and later performance.
Graphite intercalation compounds, Rb{sub x}KC{sub 8}, Cs{sub x}KC{sub 8} and Na{sub x}KC{sub 8}, x{approx equal}1-1.3, are obtained under pressures up to 80 kbar using KC{sub 8} as the initial compound. Total contents of alkali metals in these compounds correspond to the formula MC{sub 3.5-4.0}. (orig.).
The dependence of Tsub(c) on composition and deformation is calculated and compared with the corresponding dependence for Tsub(m). It is shown that superconducting and structural properties of A-15 compounds can be described, at least qualitatively, by the quasi-one-dimensional model previously developed by the authors. The superconductivity mechanism is assumed to be analogous to the BCS theory. The upper critical field Hsub(c2) of the V_3Si or Nb_3Sn compounds is found to be much greater than that in V or Nb.
The bibliography contains citations concerning the properties of tantalum and tantalum compound films formed by sputtering techniques. Topics include processes, and electrical, magnetic, and dielectric properties of the sputtered films. Tantalum compounds studied include nitrates, oxides, and aluminides. The structural properties of sputtered films are also discussed. (Contains a minimum of 105 citations and includes a subject term index and title list.)
Zr-Al metallo-organic compounds were thermally decomposed to prepare ZrO_2-Al_2O_3 composite powders. The specific surface area was dependent on the organofunctional groups of the starting organic compounds. The pore size distribution was dependent on the heating rate when the heating temperature was the same. 4 refs.; 4 figs.
This project (a) demonstrated specific dopamine transporter (DAT) uptake in vivo and metabolic stability of a radiolabelled cycloplentadieny rhenium compound in rats and baboons, (b) showed that cyclopentadieny tricarbonyl rhenium and technetium compounds conjugated tropanel could be made by metal transfer with ferrocenes; and (c) explored new methods of synthesizing these compounds under mild conditions.
The effect of irradiation using several doses of X- and #gamma#-rays (10, 20, 40, 60, 80 and 100 kGy), upon total phenolic compounds contained in the leaves of Maytenus aquifolium Martius (Celastraceae) 'espinheira santa', was investigated. The content of phenolic compounds (measured by the Folin-Denis spectrophotometric method) was unaffected by X- or #gamma#-ray irradiation, at any dose. (author)
The irreducible representations associated with states of dipole symmetry have been calculated for the space groups O/sub h//sup 3/, the space group with the correct symmetry for A-15 phase compounds. Also assembled are the character tables of the O/sub h/3 group. Thus all thedirect interband dipole-transition selection rules for A-15 compounds can easily be determined.
We present a study of the crystal field in PrNiAl, NdNiAl, ErNiAl and ErCuAl intermetallic compounds based on inelastic neutron spectroscopy. These compounds crystallize in the ZrNiAl-type hexagonal structure with an orthorhombic symmetry on rare-earth sites. The results are compared with the specific-heat data, and the lower parts of the crystal-field energy-level schemes are determined. (orig.)
We present a study of the crystal field in PrNiAl, NdNiAl, ErNiAl and ErCuAl intermetallic compounds based on inelastic neutron spectroscopy. These compounds crystallize in the ZrNiAl-type hexagonal structure with an orthorhombic symmetry on rare-earth sites. The results are compared with the specific-heat data, and the lower parts of the crystal-field energy-level schemes are determined. (orig.)
The possible existence of preferential B-site disorder in A-15 compounds recently claimed on the basis of x-ray powder diffraction data but questioned from the viewpoint of known phase diagrams is examined for some Nb-based compounds of this type. It is concluded that x-ray powder data do not allow the determination of both order and compositional variables as suggested, and the latter must therefore be determined by some other method. (author).
Chemical effects on the intensity ratio of LX-ray of molybdenum compounds irradiated by 11-keV electrons and by 3-MeV protons were studied using an x-ray crystal spectrometer. It was found that the intensity ratios of L_#gamma#_1/L_#beta#_1 markedly decrease with the increase of ionicity of molybdenum compounds, except for the case of metallic molybdenum. (author).
Observed 7-eV satellites in the XPS spectra of UGa_2 and other B-group compounds are shown to be due to two-hole final states as confirmed by existing Auger data. The presence of these satellites is an indication for a weak fd hybridization and, when compared to uranium--transition-metal compounds, increased 5f localization.
Water-resources data for the 1993 water year for Minnesota consists of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This volume contains discharge records for 58 gaging stations; stage and contents for 9 lakes and reservoirs; water quality 15 stream stations, 1 lakes station, 1 precipitation station, and water levels for 15 observation wells. Also included are 61 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are pulished as miscellaneous measurements.
Water-resources data for the 1991 water year for Minnesota consist of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. The volume contains discharge records for 60 gaging stations; stage and contents for 9 lakes and reservoirs; water quality for 18 stream stations, 1 lake station, 22 partial-record sites, 1 precipitation station, 108 wells; and water levels for 119 observation wells. Also included are 59 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are published as miscellaneous measurements or low-flow investigations.
In the National Water Plan it is described which measures must be taken to keep the Netherlands safe and livable for future generations and to make use of the chances offered by water.
swimmers in or around the water. Designate a responsible adult who can swim and knows CPR to watch swimmers in or around water. The supervisor should not be involved in any...
The energy bands and the nature of the conduction electrons have been studied for three intermetallic compounds of dysprosium. e.g., DyZn, DyCu and DyRh, following the augmented plane wave method. Density of states results are given and have implications for the stability of the structure of the intermetallic compounds of dysprosium. The charge densities and the number of conduction electrons inside and outside the APW spheres in each of these compounds are calculated; it is shown that the character of conduction electrons within the Dy APW sphere is principally of d type for all the compounds. The consequence of the predominance of d electron in the conduction bands on the various physical parameters is discussed. (author).
La{sub 1-x}Sr{sub x}MnO{sub 3} (LSMO) compounds (0.175{<=}x{<=}0.30) were prepared by conventional solid-state reaction method. Temperature dependence of the total hemispherical emittance ({epsilon}{sub H}) of the compounds from 173 to 373 K was measured on a calorimetric emissometer (CE) which was constructed based on the steady-state calorimetric method. The compounds show thermochromic properties and {epsilon}{sub H}'s have low value at low temperature and have high value at high temperature, because the compounds are dominated by metallic phase and insulator phase, respectively. We use the phase separation model to interpret the temperature dependence of {epsilon}{sub H}. (author)
We have investigated the superconducting and metallurgical properties of the ternary compounds RPd_2Si_2 and RRh_2Si_2 with R = Y, La, and Lu. All RPd_2Si_2 compounds and LaRh_2Si_2 were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases can easily mask the intrinsic (stoichiometric ratio 1:2:2) intermetallic-compound properties. Two sample-preparation techniques, viz., single crystals and off-stoichiometry, were utilized to establish where bulk superconductivity occurs. The type-I behavior of these compounds is explained with an analogous model as is used for the heavy-fermion superconductors CeCu_2Si_2 and URu_2Si_2.
With the preeminence of A-15 superconducting multifilamentary wires in magnet technology, it has become important to understand the thermodynamic factors influencing the formation of these compounds under solid-state reaction conditions. The six systems Nb--Sn, Nb--Ga, Nb--Ge, Nb--Al, V--Si, and V--Ga were prepared as single filament bronze wires and heat treated in an attempt to precipitate the appropriate A-15 compound. The compounds observed to form were categorized using a formation temperature ratio (stability index) based on the melting temperatures of the constituents which make up the single filament composites. This study has led to several predictions regarding the formation of A-15 compounds using a solid-state bronze diffusion technique. The results of experimentation based on these predictions are presented.
At-pseudohalogen compounds with SCN/sup -/ and CN/sup -/ were synthesized at the first time using At(THETA)/sup +/, At/sup 0/ and At/sup -/. Investigations of the electromigration behaviour of these compounds in free electrolytes in dependence on the SCN/sup -/ and CN/sup -/ concentrations and on pH permit deductions about compound formation and hydrolysis behaviour. The formation constant for At(SCN)/sub 2//sup -/ is 4x10/sup 2/ lxmol/sup -1/ at an ion strength of 0.05/sup 2/ molxl/sup -1/. Between pH 7 and 9 hydrolysis takes place resulting in At/sup -/. The same result has been found in the case of the hydrolysis of AtCl/sub 2//sup -/ and AtBr/sub 2//sup -/.
At-pseudohalogen compounds with SCN"- and CN"- were synthesized at the first time using At(THETA)"+, At_0 and At"-. Investigations of the electromigration behaviour of these compounds in free electrolytes in dependence on the SCN"- and CN"- concentrations and on pH permit deductions about compound formation and hydrolysis behaviour. The formation constant for At(SCN)"2"- is 4x10_2 lxmol"-_1 at an ion strength of 0.05_2 molxl"-_1. Between pH 7 and 9 hydrolysis takes place resulting in At"-. The same result has been found in the case of the hydrolysis of AtCl"2"- and AtBr"2"-. (author).
Certain allelochemicals of the marine dinoflagellate Alexandrium tamarense cause lysis of a broad spectrum of target protist cells but the lytic mechanism is poorly defined. We first hypothesized that membrane sterols serve as molecular targets of these lytic compounds, and that differences in sterol composition among donor and target cells may cause insensitivity of Alexandrium and sensitivity of targets to lytic compounds. We investigated Ca^2^+ influx after application of lytic fractions to a model cell line PC12 derived from a pheochromocytoma of the rat adrenal medulla to establish how the lytic compounds affect ion flux associated with lysis of target membranes. The lytic compounds increased permeability of the cell membrane for Ca^2^+ ions even during blockade of Ca^2^+ channels wit...
Magnetic properties of polycrystalline samples of RPd_2Si compounds (R = Gd, Tb, Dy, Ho and Er) are presented. The Gd and Tb based compounds are antiferromagnetic with Neel temperatures of 13.5 and 21 K respectively. For both compounds a metamagnetic transition is observed in low field. Moreover, in TbPd_2Si a transition between two different antiferromagnetic phases is observed at 8.5 K. The Dy, Ho and Er based compounds are ferromagnetic with Curie temperatures of 9, 3.5 ad 2.8 K respectively. The observed properties result from indirect exchange interactions and crystal field effects acting on rare earth ions which lie in a very low symmetry site. (author).
Magnetic properties of polycrystalline samples of RPd/sub 2/Si compounds (R = Gd, Tb, Dy, Ho and Er) are presented. The Gd and Tb based compounds are antiferromagnetic with Neel temperatures of 13.5 and 21 K respectively. For both compounds a metamagnetic transition is observed in low field. Moreover, in TbPd/sub 2/Si a transition between two different antiferromagnetic phases is observed at 8.5 K. The Dy, Ho and Er based compounds are ferromagnetic with Curie temperatures of 9, 3.5 ad 2.8 K respectively. The observed properties result from indirect exchange interactions and crystal field effects acting on rare earth ions which lie in a very low symmetry site.
The influence of headspace solid-phase microextraction (HS-SPME) variables, namely, sample concentration, salt concentration and sample amount, on the equilibrium headspace analysis of the main volatile flavor compounds released from soursop was investigated. A total of 35 volatile compounds, comprising 19 esters, six alcohols, three terpenes, two acids, two aromatics, two ketones and an aldehyde, were identified. The results indicated that all response-surface models were significantly (p<0.05) fitted for 10 target volatile flavor compounds. The results further indicated that more than 65% of the variation in the equilibrium headspace concentrations of target volatile flavor compounds could be explained by the final reduced models, with high R2 values ranging from 0.658 to 0.944. Multiple...
The crystal structure of R/sub 6/Cu/sub 8/Sn/sub 8/ compounds (R=Gd, Tb, Dy, Ho, Er, Tm) is determined and their magnetic susceptibility is measured in the temperature range 78-293 K. The structure of the compounds is isotypical with the Gd/sub 6/Cu/sub 8/Ge/sub 8/ type (space group Immm, Z=1). The magnetic susceptibility of the R/sub 6/Cu/sub 8/Sn/sub 8/ compounds is described by the Curie-Weiss law. Effective magnetic moments of R/sub 6/Cu/sub 8/Sn/sub 8/ compounds (R=Gd, Tb, Dy, Ho, Er, Tm) are in good agreement with theoretical values for free R/sup 3 +/ ions.
Based upon the existing regulatory cleanup criteria, remediation of this wetlands was proposed by the New Jersey Department of Environmental Protection and Energy (NJDEPE). This remedial process would have totally destroyed a thriving Old Field Wetlands. Site-Specific evaluation of the chemicals of potential concern (CPC), remaining source areas, potential environmental fate and transport (EF and T), toxicology (including oral absorption and bioaccumulation) and potential land use scenarios were conducted. It was determined that although the analytical chemistry data reported soil concentrations of arsenic, the compound used by the facility and discharged to the wetlands sediments was in fact gallium arsenide. Secondly, all remaining source areas and hot spots had previously been remediated. Vertical migration to soils had not progressed past a depth of 3 feet and groundwater/surface water did not contain significantly elevated concentrations ...
Steam generators (SGs) in PWRs and CANDUs are designed for at least a 30-year operating life. However, in the 15-25 years that SGs tubed with Alloy 600 have operated commercially, they have experienced reduced reliability, mainly due to SG tubing degradation. One of the degradation mechanisms that Alloy 600 SG tubing has suffered from is lead-induced stress corrosion cracking (PbSCC) in AVT and near-neutral SG environments. In contrast to Alloy 600 tubing, test data obtained in high temperature water indicate that Alloy 800 is resistant to cracking by lead and lead compounds. For Alloy 800 (cold worked, shot peened), the most aggressive environment is reported to be alkaline with minor concentration of PbO (80 ppm). Work by Max Helie et al. also concluded that Alloy 800 is not sensitive to lead assisted SCC for pH values close to neutrality, whereas it could be affected in high alkaline conditions. The work reported here investigated the ...
Steam generators (SGs) in PWRs and CANDUs are designed for at least a 30-year operating life. However, in the 15-25 years that SGs tubed with Alloy 600 have operated commercially, they have experienced reduced reliability, mainly due to SG tubing degradation. One of the degradation mechanisms that Alloy 600 SG tubing has suffered from is lead-induced stress corrosion cracking (PbSCC) in AVT and near-neutral SG environments. In contrast to Alloy 600 tubing, test data obtained in high temperature water indicate that Alloy 800 is resistant to cracking by lead and lead compounds. For Alloy 800 (cold worked, shot peened), the most aggressive environment is reported to be alkaline with minor concentration of PbO (80 ppm). Work by Max Helie et al. also concluded that Alloy 800 is not sensitive to lead assisted SCC for pH values close to neutrality, whereas it could be affected in high alkaline conditions. The work reported here investigated the ...
Full text: There are following general tendencies linking to SNF and radioactive waste management (RWM) in the Russian nuclear industry now. The intention to use the closed nuclear fuel cycle based on power water reactors and fast reactor. The intensification of measures aimed at the solution of 'nuclear legacy' from defenses programs of USSR. The intention to improve the existing national RW management infrastructure in the near years by means of the creation of a centralized national system (including managing corporation responsible for operation of long-storage and disposal facilities of conditioned RW). The main aims radioactive waste management (RWM) in nuclear power plants (NPP) for the next 10-15 years are to equip all NPPs with the necessary set of facilities for conditioning of the stored and currently generated RW with packaging the end-product into containers, to build regional NPPs RW repositories and to introduce evaporator bottoms selective ...
A number of high voltage cathode materials are now being considered for their ability to increase the energy density of lithium-ion batteries. In this study, a lithium-nickel composite alloy (LiNiVO{sub 4}) was synthesized using a rheological phase reduction method that incorporated mixtures of LiOH-H{sub 2}O, Ni(CH{sub 3}COO){sub 2}, 4H{sub 2}O, NH{sub 4}VO{sub 3} and C{sub 2}H{sub 2}O{sub 4}-2H{sub 2}O. The rheological phase method was used to prepare the compounds from a solid-liquid rheological mixture. Solid reactants were first mixed in a proper molar ratio, and water or solvents were added to the solid-liquid rheological body. X-ray powder diffraction (XRD) and Fourier Transform (FT) analyses were conducted to characterize the powders. Scanning electron microscopy (SEM) was used to characterize the morphological features and particle sizes of the powders. Results of the analyses indicated that the single-phase LiNiVO{sub 4} composite is ...
Investigations of alternative renewable energy resources continue, with many studies concentrating on hydrogen storage. However, there are a few problems such as storage, transportation, delivery to the user and usage safely, to be addressed to facilitate commercialization and wide usage of the hydrogen. The absorbed form within the metal hydrides seems to be the best solution of this problem. Since Li is the lightest metal, it has the advantage as the stored amount of hydrogen mass ratio. LiBH{sub 4} production process was investigated using elemental Li, B and H{sub 2}. Spex type ball milling with tungsten carbide, stainless steel and zirconia type vessels, was used to mix the different amount of Li and B under argon atmosphere. X-ray diffraction pattern demonstrated that the LiB was obtained. A system was designed to provide a hydrogen atmosphere of 60 bars to force hydrogen into the LiB structure. FTIR analysis strongly indicated the LiBH{sub 4} compound when ...
The model compounds, 8-methoxypsoralen-CH_2O(CH_2)_n-adenine (MOPCH_2OC_nAd, n=2,3,5,6,8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N"9 of adenine. UV absorption spectra are identical with the sum of MOPCH_2OC3 and adenine absorption spectra. Solvent effect on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the (#pi##->##pi#"*) state. The spectral characteristics of the fluorescence of MOPCH_2OC_nAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structrueless due to the excimer formation through the folded conformation accelerated by hydrophobic #pi#-#pi# stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, and consequently to an increase in the ...
During third quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Bis(2-ethylhexyl) phthalate exceeded final PDWS in one well. Aluminum, iron, manganese, tin, and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were ...
As human activity in and around Puget Sound increased, so did the contaminant levels in the sediment. Sediment cores collected in 1 982 revealed inputs of chemicals to the Sound, including lead (Pb), mercury (Hg), silver (Ag), copper (Cu) and petroleum hydrocarbons, began to increase above background in the late 1800s and peaked between 1945 and 1965. Synthetic organic compounds, such as polychlorinated biphenyls (PCBs) and DDT, first appeared in sediments deposited in the 1930s and reached a maximum in the 1960s. The presence of the subsurface maximum concentrations suggests that pollution-control strategies have improved the sediment quality of central Puget Sound. Additional sediment coring was performed in 1991 and samples were collected at six locations in the main basin of Puget Sound. Sediment ages were determined using Pb"2"1"0 radio isotope dating. Sedimentation rates were approximately 1 to 2 cm/yr and deposition rates ranged from 480 to 1000 mg/cm2/yr. ...
Present and potential future changes to the global environment have important implications for marine pollution and for the air-sea exchange of both anthropogenic and natural substances. This report addresses three issues related to the potential impact of global change on the air-sea exchange of chemicals: Global change and the air-sea transfer of the nutrients nitrogen and iron. Global change and the air-sea exchange of gases. Oceanic responses to radiative and oxidative changes in the atmosphere. The deposition of atmospheric anthropogenic nitrogen has probably increased biological productivity in coastal regions along many continental margins. Atmospheric deposition of new nitrogen may also have increased productivity somewhat in mid-ocean regions. The projected future increases of nitrogen oxide emissions from Asia, Africa and South America will provide significant increases in the rate of deposition of oxidized nitrogen to the central North Pacific, the equatorial Atlantic, and ...
Six major use pesticides (Atrazine, Dicamba, Isoproturon, Lindane, Paraquat and Trifluralin) with differing physico-chemical properties were evaluated for the significance of 'bound' or non extractable residue formation. Investigations were carried out in purpose-built microcosms where mineralization, volatilisation, 'soil water' extractable and organic solvent extractable residues could be quantified. Extractable residues were defined as those accessible by sequential extraction where the solvent used became increasingly non-polar. Dichloromethane was the 'harshest' solvent used at the end of the sequential extraction procedure. {sup 14}C-labelled volatilised and {sup 14}CO{sub 2} fractions were trapped on exit from the microcosm. The pesticides were categorised into 3 classes based on their behaviour. (i) Type A (Atrazine, Lindane and Trifluralin) in which ring degradation was limited as was the formation of ...
The secondary side corrosion of steam generator tubes is the main degradation of components in operating power plants, strongly impacted by chemistry. This is why EDF has largely studied the chemical parameters in its 56 PWRs which might influence corrosion development. The results of 168 hideout returns of chemical species performed on the French plants allowed to draw conclusions on where chemical species are likely to concentrate in steam generators and on the influence of several contaminants on corrosion processes: sodium, chloride, phosphate, organic compounds, etc... Based on laboratory studies and plants feedback, new chemistry specifications were established and are now applied to EDF units to minimize corrosion and operating costs and to provide a good availability while maintaining an excellent safety. Boric acid is added in the secondary water of the 10 oldest units with Inconel 600 MA tubing, highly sensitive to intergranular ...
An evaluation of eastern shale oil as an asphalt additive to reduce oxidative age hardening and moisture susceptibility is being conducted. An eastern shale oil residue having a viscosity of 1.30 Pa`s at 60{degrees}C (140{degrees}F) was blended with three different petroleum-derived asphalts that are known to be very susceptible to oxidative aging. In addition, blends of the eastern shale oil residue and the petroleum-derived asphalts are being coated onto three different aggregates that are known to be susceptible to water stripping. The oxidative age hardening portion of this study is not complete at this time. To date, information has been obtained on the unaged samples and two of the aged petroleum-derived asphalts (AAD-1 and AAK-1). When complete, this data will include rheological data on the unaged, RTFO-aged, and the RTFO/PAV-aged samples and infrared data on the unaged and RTFO/PAV-aged samples. With respect to the rheological data, asphalt AAD-1 meets the ...
Organic Rankine cycles (ORC) have unique properties that are well suited to solar power generation. In this work design and performance calculations are performed using MatLab/SimuLink computational environment. The cycle consists of thermal solar collectors (Flat Plate Solar Collector (FPC), or Parabolic Trough Collector (PTC), or Compound Parabolic Concentrator (CPC)) for heat input, expansion turbine for work output, condenser unit for heat rejection, pump unit, and Reverse Osmosis (RO) unit. Reverse osmosis unit specifications used in this work is based on Sharm El-Shiekh RO desalination plant. Different working fluids such as: butane, isobutane, propane, R134a, R152a, R245ca, and R245fa are examined for FPC. R113, R123, hexane, and pentane are investigated for CPC. Dodecane, nonane, octane, and toluene are allocated for PTC. The proposed process units are modeled and show a good validity with literatures. Exergy and cost analysis are performed for saturation ...
Developing and deploying innovative environmental cleanup technologies is an important goal for the U.S. Department of Energy (DOE), which faces challenging remediation problems at contaminated sites throughout the United States. Achieving meaningful, constructive stakeholder involvement in cleanup programs, with the aim of ultimate acceptance of remediation decisions, is critical to meeting those challenges. DOE`s Office of Technology Development sponsors research and demonstration of new technologies, including, in the past, the Volatile Organic Compounds Arid Site Integrated Demonstration (VOC-Arid ID), hosted at the Hanford Site in Washington State. The purpose of the VOC-Arid ID has been to develop and demonstrate new technologies for remediating carbon tetrachloride and other VOC contamination in soils and ground water. In October 1994 the VOC-Arid ID became a part of the Contaminant Plume Containment and Remediation Focus Area (Plume ...
There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and carbonaceous deposits, ...
The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data experimentally obtained, ...