Energy Technology Data Exchange (ETDEWEB)

The accuracy of the carbon 14 dating method is dependent on the fluctuations of carbon 14 in the atmosphere over long periods of time. Fossil corals that are dated by both carbon 14 and uranium-thorium methods allows the setting of calibration curves for the carbon 14 method for the last 50.000 years. The uranium-thorium method is based on the measurement of the ratio of 2 isotopes: thorium 230 and uranium 234 that are both present in the decay chain of uranium 238. (A.C.)

Energy Technology Data Exchange (ETDEWEB)

The present report concerns a research for the tritium and for the carbon 14 in lichens in a spirit of bio-indication: the first results appear in Daillant and al (2004 ) and additional results were presented to the congress B.I.O.M.A.P. in Slovenia, organized collectively by the institute Josef Stefan from Ljubljana and the international atomic energy agency from Vienna (Daillant and al 2003). (N.C.)

UK PubMed Central (United Kingdom)

The DUR3 gene, which encodes a component required for active transport of urea in Saccharomyces cerevisiae, has been isolated, and its sequence has been determined. The deduced DUR3 protein profile...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This evaluation has for object to inform about the levels in carbon 14 in the environment of the factories of La Hague. Two sectors were differentiated on one hand the terrestrial environment, and on the other hand the marine environment. The investigations concerned first and foremost food products stemming as the vegetable culture (vegetables) or individual breeding (milk, eggs) but also foodstuffs stemming from the local agriculture (cereal). In touch with the second sector, the marine environment, the sampling concerned the accessible products of the sea by all and those locally marketed (fishes, molluscs, shellfishes). The different results are presented in tables. (N.C.)

Energy Technology Data Exchange (ETDEWEB)

The economic attractiveness and negative environmental impact of nitrogen (N) fertilization in pastures depend on the N use efficiency in the soil-plant system. However, the recovery of urea-{sup 15}N by Panicum maximum cv. Tanzania pastures, one of the most widely used forage species in intensified pastoral systems, is still unknown. This experiment was conducted in a randomized complete block design with four treatments (0, 40, 80 and 120 kg ha-1 of N-urea) and three replications, to determine the recovery of {sup 15}N urea by Tanzania grass. Forage production, total N content and N yield were not affected by fertilization (p > 0.05), reflecting the high losses of applied N under the experimental conditions. The recovery of {sup 15}N urea (% of applied N) in forage and roots was not affected by fertilization levels (p > 0.05), but decreased exponentially in the soil and soil-plant system ...

British Library Electronic Table of Contents (United Kingdom)

The role of atmospheric urea on the biogeochemical cycle of Water Soluble 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...

International Nuclear Information System (INIS)

Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).

International Nuclear Information System (INIS)

The effect of additives on the grafting of a monomer, butylmethacrylate (BA), into simul (a soft wood) has been studied using "6"0Co source at 3 Mrad. The enhancement of polymer loading (grafting) by the addition of minute amounts (1%) of oligomers and of polyfunctional monomers into simul + BA system has been further increased in the presence of acid and urea. The synergistic polymer loading yields by acid addition cause substantial decrease of tensile strength values of wood-plastic composite; but urea increases both polymer loading and tensile strength values synergistically in these systems. (author).

International Nuclear Information System (INIS)

We simulate mountain-scale coupled heat transfer and gas flow at Yucca Mountain. A coupled rock-gas flow and heat transfer model, TGIF2, is used to simulate mountain-scale two-dimensional transient heat transfer and gas flow. The model is first verified against an analytical solution for the problem of an infinite horizontal layer of fluid heated from below. Our numerical results match very well with the analytical solution. Then, we obtain transient temperature and gas flow distributions inside the mountain. These distributions are used by a transient semianalytical particle tracker to obtain carbon-14 travel times for particles starting at different locations within the repository. Assuming that the repository is filled with 30-year-old waste at an initial areal power density of 57 kw/acre, we find that repository temperatures remain above 60 degrees C for more than 10,000 years. Carbon-14 travel ...

CERN Document Server

Defects ~10 nm in size, with number densities ~10^{10} cm^{-2}, form spontaneously beneath ion-milled, etched, or HF-dipped silicon surfaces examined in our Ti-ion getter-pumped transmission electron microscope (TEM) after exposure to air. They appear as weakly-strained non-crystalline intrusions into silicon bulk, that show up best in the TEM under conditions of strong edge or bend contrast. If ambient air exposure is <10 minutes, defect nucleation and growth can be monitored {\\em in situ}. Possible mechanisms of formation are discussed.

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This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides.

International Nuclear Information System (INIS)

Carbon-14 was analysed by direct absorption of carbon dioxide on the mixture of organic amine compound and scintillation cocktail then counted by low level liquid scintillation counter. This method can be applied for radiocarbon dating. In this study, the effects of carbon dioxide absorption, and counting efficiency were investigated using various commercial available cocktail. It was found that permafluor V and Ready Gel showed the highest carbon dioxide absorption whereas the Permafluor V showed the highest counting efficiency

International Nuclear Information System (INIS)

Using nitrogen-13 initial measurements have been made of rumen ammonia-nitrogen pool size and turnover, and rate of incorporation of ammonia into microbial protein. It is also feasible to measure the rate of incorporation of absorbed ammonia into urea and the appearance of label in saliva.

UK PubMed Central (United Kingdom)

The nephrotoxicity of cefoxitin was studied in a rat model of impaired renal function. Two levels of renal impairment were produced: "moderate," with blood urea concentrations of 100 to 150 mg/100 ml...Full Text Available

International Nuclear Information System (INIS)

Radon concentrations were continuously measured outdoors, in living room and basement in 10-minute intervals for a month. The radon time series were analyzed by comparing algorithms to extract phase-space dynamical information. The application of fractal methods enabled to explore the chaotic nature of radon in the atmosphere. The computed fractal dimensions, such as Hurst exponent (H) from the rescaled range analysis, Lyapunov exponent (#lambda# ) and attractor dimension, provided estimates of the degree of chaotic behavior. The obtained low values of the Hurst exponent (0

Science.gov (United States)

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, water solubilities, 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 was modified to an amide function, while for human sEH 2.5-fold decreased ...

British Library Electronic Table of Contents (United Kingdom)

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...

Energy Technology Data Exchange (ETDEWEB)

Standard SCR catalysts possess high activity for the hydrolysis of HNCO and thus explain the suitability of urea as a selective reducing agent for NO{sub x}. At high space velocities HNCO-slip can get perceptible over the entire temperature range. This can be attributed to the fact that the temperature dependence is strong for the SCR reaction, but weak for the hydrolysis reaction. (author) 3 figs., 5 refs.

International Nuclear Information System (INIS)

This study concerns the Souss upstream basin. The objective is to investigate the characteristics of surface water and groundwater, to assess the impact of artificial recharge as reinforcement of the natural replenishment and assess the renewal of groundwater under semi-arid area. Two major water types are observed: (i) surface waters and upstream springs (least mineralized) and (ii) all groundwater samples (prevailing calcium and magnesium bicarbonate water type). Water isotopes show a low evaporation of precipitations during infiltration. Impoverishment in heavy isotopes is the characteristic of mountain rainfalls, or of a climate colder and wetter than present. Carbon-14 activities (34-94 pmc) indicate a long residence time. The artificial recharge is low compared to the reservoir volume, due to which the renewal rate is also low.

International Nuclear Information System (INIS)

Single crystal cubic boron nitride (cBN) was heteroepitaxially grown on a seed crystal of diamond under static high pressure and high temperature at 5.5GPa and 1,600--1,700 C, respectively, for 10--100 hour. A temperature gradient method was employed for the crystal growth by using lithium boron nitride as a solvent. Initial growth feature of cBN crystal was found on the diamond seed surface after the growing time of 10 minutes. The nucleation sites of the crystals seem to be near the etch pits on the diamond surface which were introduced by the surface dissolution by the solvent for cBN growth. Two types of growth features, island and step growth were typically shown on the surface. It can be seen that grown crystal appearing as a (111) nitrogen face was exhibited with the step growth feature, while the (11n) face exhibited the island growth feature. Considering the growth process under constant P-T growing condition, growth rate of cBN ...

Energy Technology Data Exchange (ETDEWEB)

Accuracy of an LLP system and a lightning frequency map is evaluated by using transmission line faults in Hokuriku area from November in 1993 to October in 1996. The accuracy and efficiency of the system were calculated by statistical methods. From the above results, the lightning frequency map with 10 minutes meshes was proved capable of replacing the Isokeraunic Level Map with 15 minutes meshes used now for lightning protection design. However, the correlation between the number of detected lightning flashes and transmission line faults in each mesh was found to be week. This result suggests that more detailed analysis taking account of the length of transmission lines in each mesh is necessary. The correlation is stronger in winter than in summer, despite the fact that there is difference in the lightning current distribution in each mesh in winter. This characteristic can be explained if upward flashes from transmission lines are dominant ...

British Library Electronic Table of Contents (United Kingdom)

Retention and/or reincorporation of plant residues increases soil organic nitrogen (N) levels over the long-term is associated with increased crop yields. There is still uncertainty, however, about the interaction between crop residue (straw) retention and N fertilizer rates and sources. The objective of the study was to assess the influence of straw management (straw removed [SRem] and straw retained [SRet]), N fertilizer rate (0, 25, 50 and 75kgNha^-^1) and N source (urea and polymer-coated urea [called ESN]) under conventional tillage on seed yield, straw yield, total N uptake in seed+straw and N balance sheet. Field experiments with barley monoculture (1983-1996), and wheat/barley-canola-triticale-pea rotation (1997-2009) were conducted on two contrasting soil types (Gray Luvisol [Typi...

Energy Technology Data Exchange (ETDEWEB)

Wood plastic composite (WPC) formation was studied with simul wood and butylmethacrylate (BMA) at different compositions with swelling solvent methanol in the presence of a set of multifunctional acrylate monomer additives like N-vinyl Pyrrolidone (NVP), tripropylene glycol diacrylate (TPGDA) and trimethylol propane triacrylate (TMPTA) at a different doses between 1 and 3 Mrad using Co{sup 60} gamma source. This was further investigated using another set of additives chosen from oligomers such as epoxy acrylate (EA), urethane acrylate (UA) and polyester acrylate (PEA). TMPTA yielded the highest polymer loading at relatively low dose (2 Mrad). Effect of co-additives like sulfuric acid (H{sup +} ions), copper sulphate (Cu{sup 2+} ions) and urea was investigated in these series. Tensile strength (TS) of the composites were determined and the highest TS values were obtained with the composite produced in presence of urea. (author).

International Nuclear Information System (INIS)

A tri-functional polyhedral oligomeric silsesquioxane (POSS) based silane precursor R_xR_yR_z(SiO_3_/_2)_n (x + y + z = n = 6, 8, 10, ...) bearing 3-(N-(3-triethoxysilylpropyl)ureido)propyl, isooctyl and perfluoropropyl groups was synthesized and investigated as corrosion protective coating for AA 2024 alloy. Infrared reflection-absorption (IR RA) combined with X-ray photoelectron spectroscopy and atomic force microscopy provided information about partial self-assembling of coatings having a fluorine enriched upper layer with a low surface energy (#gamma#"t"o"t = 12.37 mN/m). The structural changes that accompanied corrosion produced under chronocoulometrical conditions were assessed from ex-situ IR RA spectra. A new band at 1690-1700 cm"-"1 appeared above the corrosion potential, and was assigned to the formation of amidonium ions and consequent relaxation of urea-urea associations.

International Nuclear Information System (INIS)

Astatine conversed into cationic form is shown to form stable complex with diethylenetriaminpentacetic acid. Due to this complex astatine joins RN_2 type monoclonal antibodies. More favorable conditions to prepare astatine labelled antibodies are found. Chromatographical analysis and electromigration experiments have shown that astatine is strongly retained in in-vitro biomolecule. Astatine did not escape from the labelled antibodies even in case of urea effect on them. Immune activity of astatine labelled antibodies remained similar in 20 h. 28 refs., 4 figs.

International Nuclear Information System (INIS)

Full text: Many factors including drug efficacy, compliance and antibiotic resistance may influence HP eradication rates. The "1"4C urea breath test is a sensitive method of confirming HP colonisation and eradication. The aim was to study the relationships between the peak "1"4CO_2 counts on the breath test prior to treatment, smoking and HP eradication, and to assess if persistent or recurrent symptoms implied failure of eradication. 117 patients with DU and HP colonisation proved on biopsy or rapid urease test who underwent "1"4C urea breath tests at least one month after eradication treatment was ceased were studied (69 male, 48 female, mean age 41, range 26-87 y). Questionnaire assessment of treatment regimen, smoking history and dyspeptic symptoms was made at the time of the breath test. A sub-group of 43 patients who had pre- and post-treatment breath tests was studied to assess if high peak "1"4CO_2 counts on the pre-treatment breath ...

Energy Technology Data Exchange (ETDEWEB)

Examination of a chloroform extract of Dracaena loureiri Gagnep (Agavaceae), a Thia medicinal plant possessing antibacterial activity, has led to the isolation of fifteen flavenoids. The biogenic relationships among these flavenoids isolated were briefly discussed. Definition of the skeleton and the unambiguous assignment of all of the protons of the isolates was achieved through extensive 2D-homonuclear chemical shift correlation, nuclear Overhauser effect (NOE) difference spectroscopy and 2D-NOE experiments. The {sup 1}H and {sup 13}C NMR spectra of staurosporine, a potent biologically active agent from Streptomyces staurosporeus, were unambiguously assigned by using 2D homonuclear chemical shift correlation, NOE, {sup 1}H-detected heteronuclear multiple-quantum coherence via direct coupling and via multiple-bond coupling for resonance assignments of protonated and nonprotonated carbons, respectively. S. Staurosporeus was found to utilize endogenous and exogenous D- and L-isomers of ...

International Nuclear Information System (INIS)

Determining the time of most recent fault movement is an important part of assessing a possible site for a nuclear power plant. The purpose of this paper is not to present research information but to provide a practical guide to some of the dating techniques available to the engineering geologist working on nuclear power plant siting. Emphasis is placed on the practical aspects, such as usable minerals, conditions necessary for them to yield correct dates, degree of accuracy, sample collection, sample size, and sample packaging. In this paper, the usual geologic field techniques are taken for granted (such as those used in stratigraphy, paleontology, and structural analysis) for assessing fault history. Laboratory techniques used in conjunction with or supplemental to field methods are discussed. The specific radiometric methods discussed are "1"4C(carbon-14), fission track, K-Ar (potassium-argon), thermoluminescense, Rb-Sr ...

Energy Technology Data Exchange (ETDEWEB)

A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to 4.0 metric tons, in battery weight from ...

International Nuclear Information System (INIS)

Thermoluminescence (TL) and Electron Paramagnetic Resonance (EPR) dosimetry were used to measure dose effects in borosilicate glass with time, from 10 minutes to #approx#60 days following exposure to a dose of up to 10,000 Rad. TL and EPR results were consistent and performed similarly, with both techniques capable of achieving an estimated limit of detection of between 50-100 Rad. Three peaks were identified in the TL glow curve at roughly 110 C, 205 C, and 225 C. The intensity of the 205 C peak was the dominant peak over the time period of this study. The stability of all of the peaks with time since irradiation increased with their corresponding temperature and little or no variation was observed in the glow curve response to a specified total dose attained at different dose rates. The intensity of the 205 C peak decreased logarithmically with time regardless of total dose. Based upon a conservative limit of detection of 330 Rad, a 10,000 ...

International Nuclear Information System (INIS)

Effect of helium and hydrogen production on radiation-hardening of F82H irradiated by dual or triple beam condition were investigated. The specimens used were four types of ferritic martensitic steels of F82H-std (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) steels tempered at 750degC for 60 minutes, 20% cold worked F82H steel, F82H tempered for 10 minutes and non-tempered F82H steels. The irradiation was performed at 450degC to 50 dpa under simultaneous dual beams of 10.5 MeV Fe"3"+ and 1.05 MeV He"+ or triple beams of those and 380 keV H"+ ions. The ratios of He (appm)/dpa and H(appm)/dpa were 15 nad 15 (or 150) for dual and triple ion beams. The hardness of the irradiated specimens measured at room temperature using a micro indentation after the irradiations. The hardness in these F82H steels irradiated at 450degC to 18 dpa under triple beam irradiation was harder than that under dual beam irradiation. Irradiation softening and hardening under dual beams was ...

Energy Technology Data Exchange (ETDEWEB)

In recent years the 'Nowcasting Wake Vortex Impact Variables' model NOWVIV has been developed at the Deutsches Zentrum fuer Luft- und Raumfahrt, DLR, to forecast weather parameters in airport environments. The German Meteorological Service, DWD, employs his COSMO-DE model (COnsortium for Small scale Modelling-DEutschland) for operational forecasts in Germany. A systematic comparison of model output from NOWVIV and a derivate of COSMO-DE, named COSMO-FRA, is presented. Both models are centred at Frankfurt Airport with horizontal resolutions of 2.1 km and 2.8 km, respectively. In the DLR Project Wetter and Fliegen the COSMO-FRA model will replace the NOWVIV model and become a key component in the future rapid update cycle for adverse weather predictions at the airports of Frankfurt and Munich. The forecast vertical profiles of runway crosswind, head/tail wind, temperature, and turbulent kinetic energy (TKE) are validated against Wind and Temperature Radar (WTR/RASS) ...

International Nuclear Information System (INIS)

Wood-plastic composite (WPC) formation has been studied with simul + styrene system at various compositions of styrene with methanol as the swelling solvent. Effect of additives, e.g. multifunctional monomers (MFM)and oligomers used in very low quantity (1% v/v) on the polymer loading (PL) and tensile strength (TS) of the WPC has been elaborately investigated. Enhanced PL and TS values are observed. Inorganic co-additives like Lithium (Li"+), Copper (Cu"2"+) and acid (H"+) and urea (U) used in combinations with additives (MFM or oligomers) have influenced the results of PL and TS in these systems. Li"+ ion has been a good replacement for H"+ ion; U has substantially enhanced the PL values with retention of the TS values of WPC. Co-additive Cu"2"+ used in these systems can act as a preservative and protective agent for WPC. (Author).

British Library Electronic Table of Contents (United Kingdom)

Two physical pre-treatment methods, particle size reduction by grinding and thermo-mechanical extrusion, were evaluated as alternatives to traditional biomass pretreatments for lignocellulosic ethanol. Commonly available agricultural co-products wheat bran and soybean hull were the model substrates. Extrusion led to higher reducing sugar yields as compared to grinding for wheat bran, but not in the case of soybean hulls. The best combination of extrusion screw speed and maximum barrel temperature were 7 Hz/150 ?C and 3.7 Hz/110 ?C. The use of a solvent mixture (sodium hydroxide, urea, and thiourea) and calcium chloride solution in combination with extrusion treatment did not lead to improvement in reducing sugar yield. However, extensive washing to get rid of solvents and enzymatic inhibit...

British Library Electronic Table of Contents (United Kingdom)

In this work, long-term operation of a pilot scale mixed anaerobic reactor processing crude glycerol and rapeseed meal is discussed. These materials are generated as by-products of biodiesel production. Mixed reactor was operated under mesophilic conditions for the period of 654 days. Total cumulative production of biogas reached 379 m3 (at atmospheric pressure and ambient temperature). Maximum volumetric loading achieved during the operation was 2.17 kg m?3 d?1 for the crude glycerol dose of 2 L. When dosing crude glycerol as a single substrate, average specific production of biogas of 0.76 m3 per L of the g-phase was achieved. The lack of nutrients in the g-phase had to be compensated by an addition of ammonium nitrogen in the form of urea into the reactor. Long term processing of crude ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spect...

Science.gov (United States)

The twin-cities of El Paso and Juarez share the water resources of the Hueco Bolson aquifer and overlying Rio Grande aquifer. Both aquifers span the international border between Mexico and the United States. Salinity in the Rio Grande aquifer varies widely, some parts of the shallow aquifer containing less than 1,000 mg/L total dissolved solids (TDS), other parts of the aquifer exceeding 5,000 mg/L TDS. One sizable part of the "Lower Valley" area, approximately 45 km below El Paso contains very dilute water near the outer edge of the floodplain. Historically it had been thought that the dilute waters in this location were derived from recharge from arroyos that drained proximal parts of the Hueco Bolson. Instead, our hydrogen and oxygen isotope data and carbon-14 data indicate that these dilute waters were derived from pre-dam infiltration of the Rio Grande. Relatively light and slightly evaporated pre-dam waters (-11.5 del O18) at the ...

Energy Technology Data Exchange (ETDEWEB)

YIG precursor powder was obtained by homogeneous precipitation in chloride salt solution by thermal decomposition of urea. It was found that ferric ions precipitated prior to yttrium ions. The precipitate was minute and spherical in shape. The precipitate formed consisted of the mixture of amorphous and ferric oxyhydroxide. Crystallization of YIG was proceeded by solid state reaction of intermediate YFeO{sub 3} and Fe{sub 2}O{sub 3} in the temperature range of 850 deg. C to 1400 deg. C. Single phase of YIG was obtained by heat-treatment of the powder at 1400 deg. C for 6 hrs in air. The powder calcined was molded into pellets and sintered in air. The maximum density of 4.92 g/cm{sup 3} (95.1% of theoretical density) was obtainable for the pellet sintered at 1450 deg. C using the powder calcined at 900 deg. C. (author) 20 refs., 8 figs., 1 tab.

Science.gov (United States)

Wood Plastic Composite (WPC) was prepared with simul (soft wood, density = 0.4g/cc) and butylmethacrylate (BMA) monomer using 10% methanol as the swelling agent. Effect of additives including (i) multifunctional acrylates such as tripropylene glycol diacrylate (TPGDA), trimethylol propane triacrylate (TMPTA) (ii) oligomer acrylates like the urethane (UA), epoxy (EA) and polyester (PEA) acrylates and (iii) N-vinyl pyrrolidone (NVP) was investigated using 1 to 3 Mrad dose at 0.8 Mrad/h. Synergistic increases in polymer loading yields was achieved in presence of the additives, particularly with the trifunctional acrylate (TMPTA). In addition, acid as well as urea were also used as co-additives and synergistic enhancement in yields of polymer loading were obtained. The synergistic polymer loading by acid addition causes substantial decrease in tensile strength of the composite; but other additives and co-additives increase both the polymer loading and the tensile ...

International Nuclear Information System (INIS)

The purpose was to study the toxicity of drugs known to generate free radicals on isolated pancreatic islets. The accumulattion of "8"6Rb"+ by mouse pancreatic islets was measured in vitro. Exposing the islets to 6-hydroxydopamine, minhydrin, or phenazine methosulphate + NADH inhibited the Rb"+ uptake, whereas paraquat or acetylphenylhydrazine had no effect. This effect of 6-hydroxydopamine was prevented by either of the hydroxyl radical scavengers, sodium benzoate and mannitol, but not by the non-scavenger,urea; ninhydrin was partially protected against by mannitol but not by benzoate. Protection against 6-hydroxydopamine was also afforded by D-glucose but not by L-glucose or 3-O-methyl-D-glucose; none of the sugars protected against ninhydrin. In damaging islet beta-cells and in being protected against by D-glucose, 6-hydroxydopamine closely resembles the diabetogenic drug, alloxan. It is suggested that protection against alloxan may involve both glucose ...

Energy Technology Data Exchange (ETDEWEB)

Urea-formaldehyde resin bonded particle board, medium density fiberboard and plywood paneling are used as flooring, wall paneling, for cabinet work and in furniture, and are present in almost every office, home and public building. If large quantities of these products are used in poorly ventilated spaces, high manufacturing quality control is necessary to avoid problems of latent formaldehyde release. Indoor air formaldehyde concentrations depend on the nature of the product, the product surface to air volume (loading) factor, temperature, humidity, age and product emission rates. Standard test methods are now available for measuring product emission rates that make it possible to predict the performance of UF-bonded pressed wood materials if use conditions and environmental parameters are known. Recent modifications in adhesive and board manufacturing parameters have made it possible to reduce formaldehyde emission significantly, and UF-bonded wood products are ...

Energy Technology Data Exchange (ETDEWEB)

Two physical pre-treatment methods, particle size reduction by grinding and thermo-mechanical extrusion, were evaluated as alternatives to traditional biomass pretreatments for lignocellulosic ethanol. Commonly available agricultural co-products wheat bran and soybean hull were the model substrates. Extrusion led to higher reducing sugar yields as compared to grinding for wheat bran, but not in the case of soybean hulls. The best combination of extrusion screw speed and maximum barrel temperature were 7 Hz/150 C and 3.7 Hz/110 C. The use of a solvent mixture (sodium hydroxide, urea, and thiourea) and calcium chloride solution in combination with extrusion treatment did not lead to improvement in reducing sugar yield. However, extensive washing to get rid of solvents and enzymatic inhibitors improved the conversion efficiency substantially, resulting in total reducing sugar yields of 60-73% and 25-36%, respectively, for wheat bran and soybean hull. (author)

International Nuclear Information System (INIS)

Since the radiometric measuring technique was introduced for industrial measuring and control engineering 15 to 20 years ago, the advantages of this technique have become more and more evident and have led to its world-wide application. In the last 15 to 20 years this method has become the standard one in this field. Its major advantages as compared with conventional methods are: contactless measurement; high reliability and accuracy; no mechanically moving parts; and no maintenance required. Despite higher investment costs the application of this method is paid off within a very short time owing to a higher output and the savings in maintenance costs. Some chemo-technical methods can be realized on a grand scale only when radiometric measuring equipment is used - e.g., urea plants, high-pressure polyethylene production. Especially in moisture measurements of blast-furnace coke are the economical advantages significant. Detailed studies have shown that the system ...

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine glycol.and dihydrothymine), products ...

Science.gov (United States)

The strategies employed by oral streptococci to resist the inimical influences of acidification reflect the diverse and dynamic niches of the human mouth. All of the oral streptococci are capable of rapid degradation of sugar to acidic end-products. As a result, the pH value of their immediate environment can plummet to levels where glycolysis and growth cease. At this point, the approaches for survival in acid separate the organisms. Streptococcus mutans, for example, relies on its F-ATPase, to protect itself from acidification by pumping protons out of the cells. S. salivarius responds by degrading urea to ammonia and S. sanguis produces ammonia by arginolysis. The mechanisms by which these organisms regulate their particular escape route are now being explored experimentally. The picture that emerges is that the acid-adaptive regulatory mechanisms of the oral streptococci differ markedly from those employed by Gram-negative bacteria. What remains to be ...

International Nuclear Information System (INIS)

The effectiveness of two organic chemicals, viz. 2, 4-dinitrophenyl hydrazone and naphthyl ethylene diamine applied at the rate of 10 mg kg"-"1 soil to wheat were studied as mobilizers of recently immobilized fertilizer N applied ("1"5N urea) at the rate of 60, 120 and 180 mg kg"-"1 soil to rice under greenhouse condition on a Typic Ustochrept. Rice as a first crop gave "1"5N recovery ranging from 35 to 37 per cent and more than one third of the applied fertilizer N was retained in the soil. Chemicals provided significantly higher mineral N during the initial growth period of wheat grown as a subsequent crop on the soil having different levels of residual nitrogen. "1'5N removal by plants at all the growth stages was significantly higher due to chemicals. The chemicals also showed significant effect in increasing the grain yield which caused higher N uptake and showed "1"5N recovery escalation. The "1"5N recovery at wheat harvest varied from 3 to 5 per cent of ...

Energy Technology Data Exchange (ETDEWEB)

Barbiturates substituted at the 5-position with organyltelluroalkyl or organylselenoalkyl groups were prepared by ring annulation of appropriately substituted diethyl malonates with urea or thiourea. The substituted diethyl malonates (phenyltellurobutyl(ethyl), i-propyltelluropropyl(ethyl), i-propyltelluropropyl(allyl), i-propyselenopropyl(ethyl), and phenylselenohexyl(methyl)) were prepared in 55-91% yield by reaction of diethyl omega-bromoalkyl(alkyl)malonates with organyltellurolates or selenolates (RXNa; X = Se, Te) in ethanol/benzene. The following barbiturates were obtained in 28-84% yield: phenyltellurobutyl(ethyl), m.p. 100/sup 0/C; i-propyltelluropropyl(ethyl), m.p. 119/sup 0/C; i-propylselenopropyl(ethyl), m.p. 137/sup 0/C; phenyl-selenohexyl(methyl), m.p. 124/sup 0/C. The 5-substituted thiobarbiturates i-propyltelluropropyl(ethyl)-(m.p. 75/sup 0/C) and i-propylselenopropyl(ethyl)thiobarbiturate (m.p. 83/sup 0/C) were isolated in 32 and 20% yield, ...

International Nuclear Information System (INIS)

Nitrogen metabolism and protozoa production rate using "1"4C-choline as marker were studied on 9 adult male crossbred (Tharparker x Brown Swiss) rumen fistulated animals divided into 3 groups (A, B and C). All the animals were fed concentrate mixture and wheatstraw. However, groundnut cake (GNC) in concentrate mixture was untreated in group A, 50 per cent formaldehyde treated in group B and 100 per cent formaldehyde treated in group C. Although, DM intake was similar in these groups but water intake was significantly (P<0.05) higher in control group. Total-N, ammonia-N and blood urea were significantly lower in group B and C as compared to group A. Apparent CP digestibility was not affected by addition of formaldehyde treated GNC at 50 and 100 per cent levels. However, N balances increased significantly (P<0.05) due to addition of protected protein in diet. Protozoal pool as well as production rate were significantly (P<0.01) decreased due to formaldehyde ...

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

Effect of two organic chemicals viz., 2,4-dinitrophenyl hydrazone (C_1) and naphthyl ethylene diamine (C_2) was studied by their application alone and together (Csub(1+2) at the rate of 10 ppm by growing wheat on a loamy soil (Typic ustochrept) containing recently immobilized fertilizes N of "1"5N - urea applied at 60, 120 and 180 ppm N to preceding rice under greenhouse conditions of a rice-wheat sequence. The application of C_1 and C_2 alone; and their combined application (Csub(1+2) produced 12, 15 and 18 per cent higher wheat grain yield over no-chemical application i.e. Co (3.50 g/pot). The chemicals also showed their beneficial effect on utilization of recently immobilized fertilizer N, as was evidenced by significantly higher "1"5N recovery values in wheat with C_1, C_2 and Csub(1+2)(2.84, 3.63 and 3.54 per cent, respectively) than that of Co (2.29 per cent). The soil N fractions were affected by chemical application during wheat as total hydrolyzable N, ...

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy Order 435.1, Radioactive Waste Management, requires a disposal authorization statement authorizing operation (or continued operation) for low-level waste disposal facilities. In fulfillment of these requirements, a disposal authorization statement was issued on October 25, 1999, authorizing the Hanford Site to transfer, receive, possess, and dispose of low-level radioactive waste at the 200 East Area burial grounds and the 200 West Area burial grounds. One of the conditions is that monitoring plans for the 200 East Area and 200 West Area low-level burial grounds be written and approved by the Richland Operations Office. As a result of a record of decision for the Hanford Site Solid Waste Program and acceptance of the Hanford Site Solid Waste Environmental Impact Statement, the use of the low-level burial ground (LLBG) as a disposal facility for low-level and mixed low-level wastes has been restricted to lined trenches and the Navy reactor-compartment ...

Energy Technology Data Exchange (ETDEWEB)

The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is strong, too. Should boron be added to the ...