British Library Electronic Table of Contents (United Kingdom)

The chemostat theory on two species competition has shown that the dilution rate where transition of dominance occurs - transition-dilution rate - is independent of limiting-nutrient concentration. However, we obtained the experimental data indicating that the transition-dilution rate changed with variations in limiting-ammonium concentrations, using the chemostat mixed-culture of the cyanobacterium Microcystis novacekii and the green alga Scenedesmus quadricauda. The transition-dilution rate was dependent on the concentration of limiting ammonium in the influx culture medium. We tried to simulate the experimental results. Though the dilution rate has been considered independent of nutrient concentration, we introduce the effective dilution rate that depends on nutrient concentration (ammo...

British Library Electronic Table of Contents (United Kingdom)

Oxidative degradation of methylene blue (MB) by Co^2^+-HCO3^- system with H2O2 in aqueous solution was studied. Nearly complete decolorization of the dye was obtained in less than 50min in diluted NaHCO3 solution (25mM) in the presence of only 20mM Co^2^+ ions. Meanwhile, the conjugated structure and phenyl rings of the MB molecule were destroyed or even broken down into small organic acids and inorganic ions, as indicated by FT-IR spectra and ion-chromatography. Photoluminescence probing and radical scavenging technologies suggested that the reaction of MB degradation in this system mainly involved the generation and participation of hydroxyl radicals. Furthermore, by cyclovoltammetric measurements, the in situ formed different complexes between Co^2^+ and HCO3^- were observed at differen...

International Nuclear Information System (INIS)

A procedure for the determination of lead in soil samples by "2"0"3Pb radioisotope dilution substoichiometric method is described. Japan NIES No.2 river clay standard sample and 83-40 Tibet soil standard sample were determined. The obtained values were in good agreement with reference values. The standard deviation of the method was less then 5%. Detection limit was about 0.1 #mu#g Pb.

Energy Technology Data Exchange (ETDEWEB)

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, for diethyl maleate and diglyme, reductions ...

International Nuclear Information System (INIS)

CT of the gastrointestinal tract is commonly performed after administration of a high-density diluted iodinated oral contrast material. However, because if inadequate mixing of the contrast material with the gastrointestinal contents, pseudotumor and poor mucosal visualization are frequently shown on abdominal CT. To overcome these problem, 10% corn oil emulsion (COE) is tested as an alternative oral contrast agent in 40 patients. We analyse patients tolerance, gastric mucosal visualization and discrimination of pancreas from the duodenal C-loop to 10% COE in 40 patients compared with those obtained from 35 patients, who was received high-density diluted iodinated oral contrast agent (gastrografin). The results are as follows : 1. Patients' tolerance to 10% COE is similar to that to conventional oral contrast agent. 2. Image of the gastric mucosa from patients receiving 10% COE is superior to that receiving oral contrast ...

Science.gov (United States)

Experimental investigation of the length of single burning jets of methane and hydrogen previously diluted with an inert gas (nitrogen or helium) was carried out. Efflux of fuel gases into the atmosphere occurred through cylindrical extension pieces 4 and 8 mm in diameter. The Reynolds numbers at the cut of a piece varied in the range from 400 to 12,000. A clearly defined dependence of the jet length on the quality of the added inert gas is obtained. The correlation of experimental data made it possible to recommend formulas for engineering calculations of free laminar and turbulent jets.

International Nuclear Information System (INIS)

The polycrystalline samples of Y_2_-_xHo_xO_3 (0.10#<=#x#<=#1.80) were synthesized by ceramic technology. The X-ray powder diffraction data were collected and the crystal structures were refined by the Rietveld method for the samples Y_2_-_xHo_xO_3 (x=0.00, 0.20, 0.40, 1.20, 1.80, 2.00). Holmium ions Ho"3"+ were randomly distributed over two cationic sites 8b and 24d in the space group Ia3 in all refined structures. Cation-anion-cation bonds important for superexchange interaction were determined. Magnetic susceptibility measurements were done by the Faraday method in the temperature range 290 to 620 K and a behaviour in accordance with the Curie-Weiss law was obtained. The molar Curie's constants linearly depend on concentration. The effective magnetic moments of Ho"3"+ ions were smaller than the free ion value. The Curie-Weiss paramagnetic temperatures indicated antiferromagnetic interaction. The gram ion susceptibilities confirmed the ...

International Nuclear Information System (INIS)

This paper describes the benchmark analysis results of Rapid Boron Dilution (RBD) transient tests. The RBD transient tests were carried out at University of Maryland. The data were obtained as a part of the International Standard Problem No. 43, ISP-43, for code assessment. Nuclear Power Engineering Corporation (NUPEC) participated the benchmark analysis of ISP443 with the PLASHY code. The PLASHY code is a general purpose single-phase fluid analysis code, developed by NUPEC. The code has two types of module, Cartesian/Cylindrical coordinate system module and BFC module. In order to reduce the computing time, the Cartesian/Cylindrical coordinate system module was employed. All calculations were done on a parallel computer, IBM SP2, by using the 12 of 76 CPU units. (author)

Science.gov (United States)

We have measured the Raman isotropic profiles of the ?(C?N) band at 2235 cm(-1) for five solutions of ME6N (4-cyanophenyl-4'-hexylbenzoate) liquid crystal dissolved in CCl(4) in the range from x = 0.12 to 0.007 (x, mole fraction of ME6N) and then obtained the corresponding vibrational correlation functions, C(v)(t), by time Fourier transformation. The increase with dilution of the dephasing times ?(v) complies with the behavior of the nonmonotonic concentration dependence predicted by the fluctuation concentration model for this concentration range (x Rothschild, which, being based on the assumption that the environmental modulation is described by a stretched exponential decay e(-(t/?(0))(?)), is more appropriate for the interpretation of the vibrational correlation function arising from a distribution of relaxation processes caused, as in the present case, by the persistence of pseudonematic domains. With dilution the ...

Energy Technology Data Exchange (ETDEWEB)

This study investigated the engine performance and emissions of a supercharged engine fueled by hydrogen and ignited by a pilot amount of diesel fuel in dual-fuel mode. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with charge dilution. The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first with hydrogen-operation condition up to the maximum possible fuel-air equivalence ratio of 0.3. A maximum IMEP of 908 kPa and a thermal efficiency of about 42% were obtained. Equivalence ratio could not be further increased due ...

British Library Electronic Table of Contents (United Kingdom)

Solution and dilution enthalpies of aqueous solutions of potassium diclofenac salt (K_DC) were measured by an isoperibolic calorimeter at 298.15 and 318.5?K. Heat capacities of the solutions with concentrations 0.002?0.09?mol?kg?1 were obtained at the temperature interval of 288.15?318.15?K using a scanning adiabatic microcalorimeter. The virial coefficients were derived from Pitzer?s model, and the excess thermodynamic functions of both the solvent and the solute of the solution were calculated. The concentration and temperature dependencies of thermodynamic characteristics of the solution were analyzed and discussed.

British Library Electronic Table of Contents (United Kingdom)

A method to achieve NMR of dilute samples in the earth's magnetic field by applying para-hydrogen induced polarization is presented. Maximum achievable polarization enhancements were calculated by numerically simulating the experiment and compared to the experimental results and to the thermal equilibrium in the earth's magnetic field. Simultaneous 19F and 1H NMR detection on a sub-milliliter sample of a fluorinated alkyne at millimolar concentration (1018 nuclear spins) was realized with just one single scan. A highly resolved spectrum with a signal/noise ratio higher than 50:1 was obtained without using an auxiliary magnet or any form of radio frequency shielding.

Energy Technology Data Exchange (ETDEWEB)

This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate the effect of ionic concentrating due to elevated temperature water flowing through fractures where salts and minerals have been deposited due to evaporation and boiling.

CERN Document Server

In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory method described in this Note retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The ...

Energy Technology Data Exchange (ETDEWEB)

The thesis explains the development of a mass spectrometerical isotope dilution analysis (MS/DA) for determining trace amounts of Tc. The Tc-97 isotope has been prepared by in-core irradiation of Ru of natural isotopic composition, and used as the indicator isotope. For separation of Tc-97 from the Ru matrix, a method has been developed to quantitatively separate Tc-97 from a high Ru surplus. For determining the isotope ratio for the MS/DA, a mass spectrometrical measuring technique has been found which allows reproducible measurement of the Tc-99/Tc-97 isotope ratio. Positive and, for the first time, also negative thermoionisation has been used as a method of selective ionisation of Tc. The applicability of the MS/DA for Tc trace analysis has been verified using two Al foils doped with Tc-99 or Mo-98, respectively. These have been irradiated in a nuclear reactor, the irradiation of Tc-99 yielding Ru-100, and irradiation of Mo-98 Tc-99. The ...

Science.gov (United States)

Hydrogen cyanide (HCN) production by Pseudomonas aeruginosa in a synthetic medium is stimulated by the presence of glycine. Methionine enhances this stimulation but will not substitute for glycine as a stimulator of cyanogenesis. Threonine and phenylalanine are effective substitutes for glycine in the stimulation of HCN production. Glycine, threonine, and serine are good radioisotope precursors of HCN, but methionine and phenylalanine are not. Cell extracts of P. aeruginosa convert (/sup 14/C)threonine to (/sup 14/C)glycine. H14CN is produced with low dilution of label from either (1-/sup 14/C)glycine or (2-/sup 14/C)glycine, indicating a randomization of label either in the primary or secondary metabolism of glycine. When whole cells were fed (1,2-/sup 14/C)glycine, cyanide and bicarbonate were the only radioactive extracellular products observed.

International Nuclear Information System (INIS)

The influence of 3d-transition metal impurities on the superconducting properties of the A-15 compounds V_3Si and V_3Ga have been investigated. In the case of V_3Si, the Fe impurities replacing V were found to have a local moment. A compensation effect was found in this case, resulting in a 20KOe increase in the upper critical field at dilute concentrations of Fe. It was demonstrated that long range order V_3Ga possessed higher transition temperature and upper critical field than found hitherto. Investigations on Nb_3Ge/sub 1-x/Ga/sub x/ films obtained by chemical vapor deposition has clearly shown the relation between the transition temperature and structural characteristics. The influence of generalized defects on the superconducting properties in A-15 type Nb_3X compounds has been discussed.

Energy Technology Data Exchange (ETDEWEB)

The random walk function is a mathematical function derived from studies of the mass transport and flow of diffusible materials through tubes. Approximations to the function were first used some time ago in the field of cardiac tracer dilution curves, but in the absence of rapid and reproducible curve fitting the method never became commonplace. The current study uses the latest curve-fitting techniques and shows how the method may be used with precision in the analysis of time-activity curves from dynamic oesophageal and blood flow studies. The physiological basis of the method is given and parameters obtained which relate to both the rate of flow and the local dispersion of the bolus.

Energy Technology Data Exchange (ETDEWEB)

A sensitive and rapid automated method has been developed for the selective analysis of acid extractable sulfide in environmental samples by combining gas dialysis separation techniques with methylene blue detection procedures. Acid extractable sulfide is separated from the sample matrix by the gas dialysis membrane and subsequently trapped in a dilute sodium hydroxide receiving stream. This stream is reacted with N,N-dimethyl-p-phenylenediamine and ferric chloride to produce methylene blue which is then quantitated colorimetrically at 660 nm. For standards and nonturbid environmental samples, there is good agreement between the results obtained by this procedure and the standard methylene blue method. The effect of interferences on the accurate determination of sulfide by both methods was also examined and it was found that cupric ions significantly interfered with sulfide estimation. To obtain adequate sulfide recoveries ...

International Nuclear Information System (INIS)

The molar heat capacities of chloroform, dichloromethane, methanol, acetonitrile, acetone, dimethyl sulfoxide, benzene, dimethylformamide, toluene, and cyclohexane, as well as their deuterated isotopologues, were measured using a multi-channel heat conduction TAM (Thermal Activity Monitor) III microcalorimeter. In addition, the apparent molar heat capacities of some of the associated dilute aqueous solutions (0.0039 i < 0.0210) were also measured. A temperature drop method from (298.15 to 297.15) K at 0.1 MPa was employed. The corresponding heat capacities were determined from the integration of the measured heat flow. The heat capacity results are shown to be in good to very good agreement with the available literature values. In addition, good correlations were obtained for the effect of isotopic substitution on both molar heat capacity and apparent molar heat capacity in aqueous solutions. These correlations should be useful in the ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Isotherms have been measured for H(D){sub 2}(g) solution in crystalline Pd{sub 9}Si{sub 2} in the temperature range from 235 to 373 K. The solubilities are significant, e.g., at 1.0 MPa (298 K), (H/Pd) = 0.052 or Pd{sub 9}Si{sub 2}H{sub 0.47}, however, there is no indication of hydride phase formation even down to 235 K at 1.0 MPa. The thermodynamic values for hydrogen solutions at infinite dilution of hydrogen are {Delta}H{degrees}{sub H}= -11.9 kJ/mole {1/2}H{sub 2} and {Delta}S{degrees}{sub H} = -50 J/K mole {1/2}H{sub 2}. The former is more negative than for Pd-H{sub 2} and the latter is somewhat more positive; but generally the values are not that different from Pd-H{sub 2}. The isotope effect is similar to that found for Pd-H(D){sub 2}.

Science.gov (United States)

Inductively coupled fluorocarbon (CF4/Ar and C4F8/Ar) plasmas were used to etch HfO2, which is a promising high-dielectric-constant material for the gate of complementary metal-oxide-semiconductor devices. The etch rates of HfO2 in CF4/Ar plasmas exceeded those in C4F8/Ar plasmas. The tendency for etch rates to become higher in fluorine-rich (high F/C ratio) conditions indicates that HfO2 can be chemically etched by fluorine-containing species. In C4F8/Ar plasmas with a high Ar dilution ratio, the etch rate of HfO2 increased with increasing bias power. The etch rate of Si, however, decreasd with bias power, suggesting that the deposition of carbon-containing species increased with increasing the power and inhibited the etching of Si. The HfO2/Si selectivity monotonically increased with increasing power, then became more than 5 at the highest tested bias power. The carbon-containing species to inhibit etching of Si play an important role in ...

UK PubMed Central (United Kingdom)

Therapeutic embolization is defined as the voluntary occlusion of one or several vessels, and this is achieved by inserting material into the lumen to obtain transient or permanent thrombosis in the...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Here we present evidence that in water/acetonitrile solvent detailed structural and dynamic information can be obtained for important proteins that are naturally present as oligomers under native conditions. An NMR-derived human insulin monomer structure in H{sub 2}O/CD{sub 3}CN, 65/35 vol%, pH 3.6 is presented and compared with the available X-ray structure of a monomer that forms part of a hexamer (Acta Crystallogr. 2003 Sec. D59, 474) and with NMR structures in water and organic cosolvent. Detailed analysis using PFGSE NMR, temperature-dependent NMR, dilution experiments and CSI proves that the structure is monomeric in the concentration and temperature ranges 0.1-3 mM and 10-30 deg. C, respectively. The presence of long-range interstrand NOEs, as found in the crystal structure of the monomer, provides the evidence for conservation of the tertiary structure. Starting from structures calculated by the program CYANA, two different molecular ...

International Nuclear Information System (INIS)

The AC susceptibility of La_xNd_1_-_xF_3 single crystals, for 0#<=#x#<=#0.1, has been measured from 1.5 up to 40 K and their DC susceptibility for 0#<=#x#<=#1 has been measured from 3 up to 300 K in magnetic fields up to 0.2 T. In both susceptibilities the magnetic fields were applied parallel to the crystallographic a-axis (perpendicular to the c-axis). The effective Bohr magneton number p_e_f_f and paramagnetic Curie temperature #theta#_p have been obtained, using the Curie-Weiss law in the temperature range 100-300 K. Also the g-values corresponding to the five Kramers doublets in the "4I_9_/_2 ground multiplet of Nd"3"+ ion in La_xNd_1_-_xF_3 have been determined in the direction perpendicular to the c-axis, using the Van Vleck theory of paramagnetic susceptibility. The effect of the dilution of the paramagnetic Nd"3"+ ions with diamagnetic La"3"+ ions is also discussed. (orig.).

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SiO{sub 2}, TiO{sub 2} and AlO(OH) powders obtained by the sol-gel method were investigated by transmission electron microscopy. The mass-radius relation was used to determine the fractal dimensions from the images. These fractal dimensions were corrected in order to obtain the powder fractal dimensions. The results indicate a good fractal behavior and high fractal dimensions.

CERN Document Server

Hydroxyapatite samples were produced by two different wet-chemical methods, and characterized by x-ray diffraction, infrared and compression strength measurements. The x-ray diffraction measurements were simulated using the Rietveld method, and structural data as lattice parameters and average crystallite size were obtained. The infrared spectra showed the presence of CO$_3^{2-}$ ions in all samples, indicating a contamination by these ions. By mixing samples produced by both methods, a bioceramic was obtained and, after sintering, samples with very high compression strengths (26--30 MPa) were obtained.

Energy Technology Data Exchange (ETDEWEB)

Apparent molar volumes of aqueous methyldiethanolamine and its salt were determined with platinum vibrating tube densitometers over a range of temperatures from 283K=<T=<576K and at pressures from 0.1MPa to 20MPa. Apparent molar heat capacities were obtained using a Sodev Picker flow microcalorimeter at a pressure of 0.1MPa and within the temperature range of 283K=<T=<328K. Apparent molar adiabatic and isothermal compressibilities at a pressure of 0.1MPa were obtained at temperatures from 283K=<T=<313K with speed of sound measurements. The experimental results were extrapolated to infinite dilution to obtain values for the standard partial molar volumes V{sup o}, heat capacities C{sub p}{sup o}, and isothermal compressibilities {kappa}{sub T}{sup o}. The standard partial molar volumes V{sup o} for the neutral amine and its salt show increasingly positive and ...

Energy Technology Data Exchange (ETDEWEB)

The effects of dilute impurity doping on charge-density wave (CDW) structures and gaps in NbSe{sub 3} 1T-TaS{sub 2} and 2H-NbSe{sub 2} have been studied by using a scanning tunneling microscope (STM) operating at 4.2 K. In Fe doped samples of NbSe{sub 3} the STM spectroscopy measurements indicate that the added impurities can significantly shift the CDW energy gaps. In NbSe{sub 3}, Fe reduces both CDW gaps by 25-30%, and produces changes in the conductance structure relative to the pure material. The images of Fe{sub 0.01}NbSe{sub 3} show that all three surface chains in the unit cell still carry a strong CDW modulation with no evident disorder. However, a change in the relative amplitudes of the high and low temperature CDWs is detected. The effects of Co and Ni impurities on the gaps in NbSe{sub 3} have also been studied. While Co increases both by 25-30%, Ni increases only the high temperature gap with the low temperature gap remaining ...

Energy Technology Data Exchange (ETDEWEB)

During the last years one focus of German PWR safety analysis was boron dilution events with the potential of reactivity transients. Coolant with a low boron concentration could be collected in localized areas of the reactor coolant system e.g. by separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux- condenser heat transfer after a small break loss of coolant accident with a limited availability of the emergency core cooling systems. The TUeV NORD SysTec was charged by German supervisory authorities with the assessment of the safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses shall demonstrate that boron dilution ...

Energy Technology Data Exchange (ETDEWEB)

During the last years, boron dilution events with the potential of reactivity transients were an important issue of German PWR safety analyses. A coolant with a low-boron concentration could be collected in localized areas of the reactor coolant system, e.g., by separation of a borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux-condenser heat transfer after a small break loss of coolant accident with a limited availability of the emergency core cooling systems. During the course of follower core assessments, TUV NORD SysTec appraises safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses demonstrate that boron dilution events ...

Science.gov (United States)

ing materials were ASARCO, 59 purity, copper, silver and gold, while the silicon was Dow-Corning semi- conductor grade (69 purity). ...

UK PubMed Central (United Kingdom)

The in vitro susceptibility of Actinobacillus actinomycetemcomitans to azithromycin, a new macrolide antibiotic of a new class known as azalides, was compared with that of erythromycin by the agar dilution...Full Text Available

Science.gov (United States)

... Abstract : The electric resistance in weak (diluted) solid solutions of the Pd-Ag and Fe-W systems, as wellAS THE Hall effect in a Pd-Ag system ...

Energy Technology Data Exchange (ETDEWEB)

This study was aimed to test and select hydrophobic activated charcoal, manufactured in Romania, used as adsorbents of solvents which partly compose diluters employed in car industry. With regard to the diluters, three of the seven types of activated charcoal studied (Sorbent 1, R - Cafs and AD3) showed the greatest capacity of adsorption, when determined under dynamic and static conditions. (authors) 8 refs.

Energy Technology Data Exchange (ETDEWEB)

A micellar method has been used to prepare silver-coated cobalt (Co-Ag) nanoparticles. The synthesized particles have been deeply characterized by several methods, i.e., XRD, UV-Vis, TEM, XPS, and electrochemical techniques. There is every indication that the obtained particles show a truly core-shell structure. All the nanoparticles obtained under different conditions are in the size range 3-5 nm. High-resolution TEM (HRTEM), Fast Fourier Transformation (FFT), and Selected Area Electron Diffraction (SAED) indicated that the presence of hcp-Co and fcc-Ag, in which cobalt is located in the central area; meanwhile silver is at the edges of the nanoparticle. The absorption band of the Co-Ag colloid shifts to a longer wavelength and broadens relative to that of pure silver colloid. Voltammetric characterization allowed to determine the coverage of the cobalt core.

British Library Electronic Table of Contents (United Kingdom)

Novel fluoroalkyl end-capped vinyltrimethoxysilane oligomeric nanoparticles were prepared by the hydrolysis of the corresponding oligomer under alkaline conditions. The size of fluorinated nanoparticles thus obtained is of submicrometer levels and is not sensitive to the refractive indices of a variety of solvents; however, the turbidity of the dispersed fluorinated nanoparticles is extremely sensitive to the refractive indices of these solvents. In particular, the solvents of which the refractive indices are from 1.378 to 1.408 were found to afford the transparent colorless dispersed particle solutions. More interestingly, the modified glass surface treated with fluorinated nanoparticles exhibited a completely superhydrophobic characteristic (a water contact angle: 180?) with a nonwetting...

Science.gov (United States)

The authors described a method for determination of tissue renin activity with heterologous substrate. The preparation of the substrate was performed at several stages: salting with amonium sulfate; dialisis of the precipitate till complete separation of amonium sulfate molecules; distruction of angiotensinases by interchangeble souring and alcalization of the medium; lyophylization of the pure substrate. The obtained renin-substrate was preserved in ampules and its usage had a series of advantages--duration, economic, a possibility for standartization of the determination, etc., which were described in details in the article. The described in details also the quantitative determination of the renin activity in the tissues (renal and cerebral) with the help of the obtained substrate as the moments, modiied by the authors, were indicated. PMID:436712

Energy Technology Data Exchange (ETDEWEB)

Electron scattering data have been used to obtain transition charge densities for the low-lying E2 transitions in /sup 88/Sr, /sup 89/Y, and /sup 90/Zr. These charge densities show a characteristic shape indicative of their microscopic constituency, modified by core-polarization effects. A good description of transitions in the even-even nuclei is obtained by using the measured single-particle transitions in /sup 89/Y as effective densities. .ID LV2086 .PG 19 22

Energy Technology Data Exchange (ETDEWEB)

Tree swallows were used to evaluate movement and potential impacts of contaminants from sediments in Newton Creek (diesel range organics: DROs) and Sheboygan River (PCBs), tributaries to Lake Superior and Lake Michigan, respectively. Contaminated sites occurred along the course of each river, while reference sites were located upstream or on a nearby river. Productivity was monitored and eggs, day 1 nestlings, and day 12 nestlings were collected from each nest. Whole body or egg homogenates were analyzed for PCBs or DROs. EROD activity in livers from day 12 nestlings is being determined for both PCB and DRO exposures. In the Newton Creek study, hatching success was similar for DRO and reference sites. DROs were detected in gastrointestinal tracts of 1 nestling from the reference and 1 from the contaminated site. DROs were not detected in any egg samples. In the Sheboygan River study, hatching success rates differed between 1 reference and 1 contaminated river segment. PCB daily ...

Science.gov (United States)

Correlates between immunological parameters and protection against Bacillus anthracis infection in animals vaccinated with protective antigen (PA)-based vaccines could provide surrogate markers to evaluate the putative protective efficiency of immunization in humans. In previous studies we demonstrated that neutralizing antibody levels serve as correlates for protection in guinea pigs (S. Reuveny et al., Infect. Immun. 69:2888-2893, 2001; H. Marcus et al., Infect. Immun. 72:3471-3477, 2004). In this study we evaluated similar correlates for protection by active and passive immunization of New Zealand White rabbits. Full immunization and partial immunization were achieved by single and multiple injections of standard and diluted doses of a PA-based vaccine. Passive immunization was carried out by injection of immune sera from rabbits vaccinated with PA-based vaccine prior to challenge with B. anthracis spores. Immunized rabbits were challenged by intranasal spore ...

Energy Technology Data Exchange (ETDEWEB)

The application of the large-bore direct injection high efficiency nebulizer (LB-DIHEN) for the determination of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine by inductively coupled plasma mass spectrometry (ICP-MS) is described. The LB-DIHEN is compared with the standard method using a concentric pneumatic nebulizer and cyclonic spray chamber. In addition to the toxicological significance of As, Cd, Pb, and Hg, these elements represent a cross-section of analytical issues including spectral interferences (e.g., {sup 40}Ar{sup 35}Cl{sup +} on {sup 75}As{sup +} and {sup 98}Mo{sup 16}O{sup +} on {sup 114}Cd{sup +}) and memory effects (Hg). In this study, the low sample consumption of the LB-DIHEN is used to reduce the volume of urine needed for analysis, and to reduce the volume of final diluted sample required for analysis. Eliminating the spray chamber and reducing the dead volume of the nebulizer reduces memory effects, especially for analytes ...

International Nuclear Information System (INIS)

The formation of #alpha#'-sialon using Li as a modifying cation was investigated. The effects of the Li content, firing temperatures and Si/Al ratios on #alpha#'- yield were studied. The results indicated that at lower sintering temperatures the stabilisation of #alpha#'-sialons was obtained but the high weight losses of Li at higher temperatures limited the stabilisation. Increased ''Al'' content in the compositions resulted in an increase in the stability of Li-#alpha#'-sialon at higher temperatures, by the formation of a liquid phase which retains Li in the system. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Substantial changes in the radial distribution function of amorphous Si films have been observed in neutron-diffraction studies. The spectra indicate changes in short-range order associated with an approx.11% modification in the bond-angle distribution width. The results allow the first direct comparison of structural and vibrational Raman probes of variations in local order in thin-film amorphous solids. Good agreement is obtained between the measured bond-angle variation and that based on Raman estimates.

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In this paper the possibility of configuring a water cooled Nuclear Thermal Propulsion (NTP) rocket, based on a Particle Bed Reactor (PBR) is investigated. This rocket will be used to operate on water obtained from near earth objects. The conclusions reached in this paper indicate that it is possible to configure a PBR based NTP rocket to operate on water and meet the mission requirements envisioned for it. No insurmountable technology issues have been identified.

Energy Technology Data Exchange (ETDEWEB)

Compton scatter tomography utilizes the electronic collimation characteristics available through the Compton scattering angle-energy correlation to obtain tomographic images. In this work we present particular aspects of the technique, which are relevant to the inverse radiation transport problem of reducing marginal projection data to radial two-phase flow regime maps. The results indicate a viable technique for the tomographic imaging of tow-phase flow using practical source strengths and reasonably few detectors.

British Library Electronic Table of Contents (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

Positron annihilation experiments on Fe-Cu model dilute alloys of nuclear reactor pressure vessel (RPV) steels have been performed after neutron irradiation in JMTR. Nanovoids whose inner surfaces were covered by Cu atoms were clearly observed. The nanovoids transformed to ultrafine Cu precipitates by dissociating their vacancies after annealing at around 400degC. The nanovoids and the ultrafine Cu precipitates are strongly suggested to be responsible for irradiation-induced embrittlement of RPV steels. Effects of Ni, Mn and P addition on the nanovoid and Cu precipitate formations were also studied. The nanovoid formation was enhanced by Ni and P, but suppressed by Mn. The Cu precipitates after annealing around 400degC were almost free from these doping elements and hence were pure Cu in the chemical composition. Furthermore the Fermi surface of the 'embedded' Cu precipitates with a body centered cubic crystal structure was ...

Science.gov (United States)

Sixty-Hz magnetic field exposures were measured for 45 adult residents of Maine. Thirty of the subjects resided near rights-of-way (ROWs) with either 345- and 115-kV transmission lines, or ROWs with only 115-kV transmission lines; fifteen resided far from any transmission lines. Personal exposure data for a single 24-hour period was acquired with the EMDEX. The EMDEX's event-marker button was used to partition exposures into Home and Away components. Also, three area measurements were taken for each subject during the personal exposure measurement period: (1) 24-hr fixed-site bedroom measurement with a second EMDEX; (2) Spot measurements in at least three rooms of every residence; and (3) Spot measurements outside each residence. Residence near transmission lines highly loaded during the measurement period was associated with increased Home and Total exposure relative to a far-away population. Average exposure level while away from home was uniform (at about 2 mG) throughout ...

International Nuclear Information System (INIS)

The purpose of this work is to investigate the possible role of Helical CT defecography in pelvic floor disorders by comparing the results of the investigations with those of conventional defecography. The series analyzed consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with Helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; it is used a remote-control unit. The parameters for Helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 m As and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position ...

British Library Electronic Table of Contents (United Kingdom)

Objective To investigate value of magnetic resonance cholangiopancreatography (MRCP) using oral diluted gadolinium (Gd)-diethylenetriamine penta-acetic acid (DTPA) as negative contrast materials in diagnosis of juxtapapillary duodenal diverticulum with atypical imaging features. Methods Nineteen patients with juxtapapillary duodenal diverticula of which imaging findings were atypical underwent MRCP using oral diluted Gd-DTPA as negative contrast materials after conventional MRCP without any oral contrast materials. Results Twenty diverticula were revealed in the 19 patients. At conventional MRCP, the diverticula appeared as rounded lesion with high signal intensity. After oral administration of diluted Gd-DTPA, they disappeared at MRCP. These entities were diagnosed as duodenal diverticula...

International Nuclear Information System (INIS)

Inherent boron dilution can occur in case of a Small Break LOCA when low borated water is mainly accumulated in the U-legs due to reflux boiling in the Steam Generator tubes after the loss of natural circulation. The restart of the natural circulation may lead to criticality because of the injection of these low borated slugs towards the core. To evaluate this potential risk, the boron concentration at the core inlet has to be known which makes necessary to estimate the mixing phenomena in the cold leg, in the downcomer and in the lower plenum: CFD calculations are required. First of all the validation of CFX5 CFD code on the relevant phenomena of inherent boron dilution has been established (UPTF TRAM C3 test). Then, an application to the 900 MW French Pressurized Water Reactor series has been performed. (authors)

International Nuclear Information System (INIS)

High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu_2O_3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.

International Nuclear Information System (INIS)

Inherent boron dilution can occur in case of a small Break LOCA when low borated water is accumulated in the U-legs due to reflux boiling in the Steam Generator tubes after the loss of natural circulation. The restart of the natural circulation may lead to criticality because of the injection of these low borated slugs towards the core. To evaluate this potential risk, the boron concentration at the core inlet has to be known which makes necessary to estimate the mixing phenomena in the cold leg, in the downcomer and in the lower plenum: CFD calculations are required. First of all the validation of CFX5 CFD code on the relevant phenomena of inherent boron dilution has been established (UPTF TRAM C3 test). Then, an application to the 900 MW French Pressurized Water Reactor series has been performed. (authors)

International Nuclear Information System (INIS)

The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50?60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency can reach to 90% of extraction efficiency mixed with 1% manganese dioxide, 12% sulfuric acid pugging, curing 3 days and leached ...

Energy Technology Data Exchange (ETDEWEB)

This study investigated the engine performance and emissions of a supercharged dual-fuel engine fueled by hydrogen-rich coke oven gas and ignited by a pilot amount of diesel fuel. The engine was tested for use as a cogeneration engine, so power output while maintaining a reasonable thermal efficiency was important. Experiments were carried out at a constant pilot injection pressure and pilot quantity for different fuel-air equivalence ratios and at various injection timings without and with exhaust gas recirculation (EGR). The experimental strategy was to optimize the injection timing to maximize engine power at different fuel-air equivalence ratios without knocking and within the limit of the maximum cylinder pressure. The engine was tested first without EGR condition up to the maximum possible fuel-air equivalence ratio of 0.65. A maximum indicated mean effective pressure (IMEP) of 1425 kPa and a thermal efficiency of 39% were obtained. ...

International Nuclear Information System (INIS)

Results of hot cracking on welds with compositions between alloy 800 and AWS ER NiCr 3. Investigation of the influence of Si, Mn, Ti and Al on the hot cracking suscpetibility of the alloy 800. (orig.).

UK PubMed Central (United Kingdom)

Randomly amplified polymorphic DNA (RAPD) analysis and the PCR assay were used in combination with dilution plating on a semiselective medium to detect and enumerate propagules of Trichoderma...Full Text Available

Science.gov (United States)

Maintenance energy expenditures were mesured for five rumen bacteria, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Bacteroides ruminicola, Megasphaera elsdenii, and Streptococcus bovis, by using a complex medium with glucose as the carbon source. Large differences (as high as 8.5-fold) in maintenance energy expenditures were seen among these bacteria. The suggestion is made that maintenance requirements could be a significant determinant of bacterial competition in the rumen. Theoretical maximum growth yields, calculated from double reciprocal plots of yield versus dilution rate, were compared to theoretical Y(ATP) values in order to estimate minimum molar adenosine 5'-triphosphate yields from glucose for each bacterium. Results showed that relative yield among the bacteria was growth rate dependent. At high dilution rates, both S. ruminantium and S. bovis produced lactate as their principal fermentation product. At lower ...

Energy Technology Data Exchange (ETDEWEB)

We consider the case of a test sphere (ball) of radius a{sub 1} rotating at constant angular velocity {omega} in an otherwise quiescent unbounded suspension of uniformly sized spheres of radii a{sub 2} dispersed in a Newtonian fluid of viscosity {mu}. To the first order in the volume fraction c of suspended spheres it is shown that when the ball is small compared with the suspended spheres the suspension does not behave as regards the hydrodynamic torque L exerted on the ball like a homogeneous Newtonian fluid characterized by the usual Einstein viscosity coefficient {mu}{sub s}={mu}(1+5/2c). Explicitly, the torque on the rotating sphere does not obey Kirchoff{close_quote}s law, L=8{pi}{mu}{sub s}a{sub 1}{sup 3}{omega} for no slip. Rather, a modified form of Kirchoff{close_quote}s law is obtained in which the Einstein coefficient of 5/2 is multiplied by a coefficient which is less than unity in magnitude and is functionally dependent only upon the ...

Energy Technology Data Exchange (ETDEWEB)

The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to bacteria to grow on ...

British Library Electronic Table of Contents (United Kingdom)

A study of the effect of a clayey soil modified in situ and ex situ with the cationic surfactant octadecyltrimethylammonium bromide (ODTMA), on the retention of linuron, atrazine and metalaxyl was carried out. Leaching of these compounds was studied in columns of a natural clayey soil and the same clayey soil modified by direct injection of the surfactant in situ, and in columns of a natural sandy soil and the same sandy soil modified by intercalation of a barrier of the clayey soil saturated ex situ with the surfactant. Breakthrough curves indicated the total immobilization of linuron in modified soils and a decrease in the leaching kinetics of atrazine and metalaxyl compared to what was obtained in the natural soil. The results indicate the use of the clayey soil modified in situ or ex s...

British Library Electronic Table of Contents (United Kingdom)

Chemical modification of poly(?-caprolactone) PCL by oxidation with potassium permanganate in solution was investigated. According to the data obtained from Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance 1H NMR, after the oxidation reactions the PCL chains exhibited new functional groups (vinyl and hydroxyl) and possible intermolecular recombination, producing an oxidized-polycaprolactone (PCL-OX). Solution viscometry indicated that degradation also occurred during the oxidation reactions (30% drop in viscosity average molecular weight was detected). Differential scanning calorimetry (DSC) also indicated that PCL was chemically modified and degraded. The successive self-nucleation/annealing (SSA) treatment confirmed that a reduction (or interruption) in line...

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 (0indicated anti-persistent behavior (non random changes) of the time series, but the positive values of the #lambda# pointed out the grate sensitivity on initial conditions and appearing deterministic chaos by radon time variations. The calculated fractal dimensions of attractors indicated more influencing (meteorological) parameters on radon ...

Energy Technology Data Exchange (ETDEWEB)

Data from a detailed evaluation of environment conditions in three U.S. Army field stations are presented. Three field stations were evaluated: Kunia, Augsburg, and Berlin. Results from a questionnaire administered to over 600 people at all sites in three job types (operator, analyst, and administrative/other) are given which indicate major concerns with conditions such as temperature, lighting, space, furniture, equipment functioning, and general environmental quality. Physical data obtained from measurements of over 270 work stations indicated the presence of cold temperatures, low light levels, reduced VDT screen contrast, glare, and distracting noises. The report provides the basic data that support the concerns expressed by Headquarters; namely, that field-station personnel perform their jobs under conditions likely to impair their effectiveness. Suggestions for improving conditions are given in a companion report by ...

International Nuclear Information System (INIS)

Differential cross sections for 201.5 MeV proton scattering form "8"8Sr were measured. From the analysis of the elastic data, no unique optical-model potential could be obtained, but the radial moments are well determined. In a macroscopic analysis of the collective states it turns out that if the optical potential and transition potential are chosen consistently, unambiguous potential deformation lengths can be obtained even though the optical potential is not unique. Taking into account the range and density dependence of the underlying effective interaction reliable neutron deformation lengths can be obtained. For inelastic transitions of various character microscopic distorted-wave calculations with a density-dependent interaction based on the Paris potential were performed. The nuclear structure was taken from one broken-pair calculations in a large model space, calibrated by (e,e') data. In general a good description ...

Science.gov (United States)

The authors made peritoneal dialisis with 5% of glucose (7 ml/kg of body weight) in 11 dogs under the conditions of an acute experiments. They examined cortiosl and ADH activity, hematocrite and plasma protein in the samples of blood, obtained on the 20th and 50th minute. ADH was titrated biologicaly by a new method, proposed by Nacev. The results were compared with the changes in the circulatory and renal indices, obtained at the same procedure in the preceding investigations. There was an increase in the cortisol and ADH activity, which could be explained by the total hypovolemia, induced by peritoneal dialisis. The increase of the cortisol level is described as a separate link in a more complex mechanism, assuring metabolic homeostasis. PMID:1222705

International Nuclear Information System (INIS)

Studies on the separation of Ag(I) during the recovery of Pu from analytical waste generated during potentiometric determination of Pu using AgO as oxidant, by precipitation of Pu as ammonium plutonium (III) oxalate have shown that most of the Ag(I) is separated during the reduction of Pu to Pu(III) state by ascorbic acid. A decontamination factor of 54 was obtained. Additional a decontamination factor of 5.8 was obtained during the precipitation of Pu as ammonium plutonium (III) oxalate. The Ag content was determined by gamma spectrometry, using "1"1"1Ag as a tracer (T_1_/_2 7.45 d, #gamma# 342.1 keV) and HPGe as detector. The studies indicate that Ag is preferentially separated almost quantitatively during the recovery of plutonium, when acidity adjustment is done with NaOH instead of NH_3. (author)

Energy Technology Data Exchange (ETDEWEB)

A variable-compression ratio, direct-injection diesel engine (VCR) has been designed and assembled at Southwest Research Institute with the intention of examining the current procedures for rating the ignition quality of diesel fuels and the meaning of ignition delay as an indicator of ignition and combustion quality. Using a slightly modified ASTM D 613 procedure, the engine has been used to rate the ignition quality of 43 different test fuels. The ratings obtained in the VCR engine are compared to the corresponding rating obtained using the standard cetane rating procedure. Some of the problems associated with the standard procedure became apparent during these experiments. The experimental results are discussed in terms of the problems and the advantages of a proposed VCR-based rating procedure.

Energy Technology Data Exchange (ETDEWEB)

Wood polymer composite (WPC) specimens were produced by impregnating a tropical wood with methyl methacrylate and subsequently polymerised by ..gamma..-irradiation. Beam specimens of varying weight percentages of polymer were then subjected to a three point bend creep test under a constant load condition, for 250, 300 and 350 N. A Norton-Bailey (power law) mathematical model was used to describe the creep behavior, with the creep components determined by a nonlinear regression analysis. Significant creep improvements were obtained from the composite specimens as compared to the untreated wood specimens. Results indicated that maximum creep resistance is obtained when the amount of polymer loading exceeded 30%. An interfacial interaction between the polymer and the wood cell wall was used to account for the behavior of the increase in the creep resistance.

Energy Technology Data Exchange (ETDEWEB)

Ammonia borane (AB) and sodium borohydride (SBH) are candidate materials for on-board hydrogen storage that can be dehydrogenated upon demand. The rheological properties of the dehydrogenated by-products are important to quantify their removal and transportability from the hydrogen storage system. This paper presents visco-elastic property (elastic stiffness and viscous damping) measurements of the spent fuels obtained from AB hydrolysis, hydrothermolysis and thermolysis; and SBH hydrolysis. Smaller stiffness and larger mobility (or smaller viscous damping) indicate better transportability of the spent fuel. In addition, flow property (dynamic angle of repose and avalanching time) measurements for the hydrolysis spent fuels of AB and SBH are also presented. Comparing with the SBH hydrolysis spent fuel, the AB hydrolysis spent fuel had a lower stiffness and larger mobility, as well as lower angles of dynamic repose and avalanche power peaks, ...

International Nuclear Information System (INIS)

In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. ...

Energy Technology Data Exchange (ETDEWEB)

Results are reported of photoemission studies using laser pulses of 10 ps duration and 4.66 eV photon energy on metal cathodes. These included thin wires, flat surfaces and an yttrium cathode with a grainy surface. The measurements of current density and quantum efficiency under low and high surface fields indicate that field assisted efficiencies exceeding 0.1% and current densities exceeding 10/sup 5/ A/cm/sup 2/ are obtainable. The results are compared to the requirements of switch power applications. 24 refs., 13 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

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.

CERN Document Server

The determinants of the velocity of money have been examined based on life-cycle hypothesis. The velocity of money can be expressed by reciprocal of the average value of holding time which is defined as interval between participating exchanges for one unit of money. This expression indicates that the velocity is governed by behavior patterns of economic agents and open a way to constructing micro-foundation of it. It is found that time pattern of income and expense for a representative individual can be obtained from a simple version of life-cycle model, and average holding time of money resulted from the individual's optimal choice depends on the expected length of relevant planning periods.

Energy Technology Data Exchange (ETDEWEB)

Laser Doppler velocimetry and other photometric techniques are evaluated for measuring the average particle velocity in an ensemble of free-falling particles. The ability to obtain measurements in the presence of a radiant flux as high as 0.6 MW/m/sup 2/ was part of the evaluation. Optically dissimilar particles with diameters ranging from 0.1 mm to 1 mm were used in the study. Experimental results indicate that ensembles of particles do not behave as single isolated particles. The particle motion is dependent on particle volume fraction, and is quite unstable for falls greater than one meter.

CERN Document Server

Similarity searching finds application in a wide variety of domains including multilingual databases, computational biology, pattern recognition and text retrieval. Similarity is measured in terms of a distance function edit distance in general metric spaces, which is expensive to compute. Indexing techniques can be used reduce the number of distance computations. We present an analysis of various existing similarity indexing structures for the same. The performance obtained using the index structures studied was found to be unsatisfactory . We propose an indexing technique that combines the features of clustering with M tree(MTB) and the results indicate that this gives better performance.

International Nuclear Information System (INIS)

Conduction properties of Rb"+ ion in Rb-Al-priderite and K"+ ion and Rb"+ ion in (K,Rb)-Al-priderite, were investigated by NMR using "2"7Al in the framework as a probe. Size effect was observed remarkably in the activation energies. Frequency dependence of T_1 in Rb-Al-priderite at a low temperature indicates that the relaxation behavior of "2"7Al in Rb-Al-priderite can be described by the continuum model. Barrier height distributions and 'attempt frequencies' in both samples obtained by a curve-fitting method are discussed in comparison with those of K-Al-priderite. (orig.).

International Nuclear Information System (INIS)

The formation of the ions charge and energy distributions of the ions slowed down or randomly changing their charge in the collisions with the medium particles are studied. The effect of the ions dispersion by the charge on the Bragg curve form is investigated. The proposed diffusion approximation for the heavy ions kinetic equation makes it possible to determine simply the parameters of the ions distribution by charge and energy on the whole way of the ions motion. The relation between the ions charge distribution characteristics and the cross sections of the ionization-recombination processes is indicated. The ions distributions, calculated in the proposed analytical model, are compared with the results of the numerical calculations. Good agreement between the analytical, numerical and experimental results is obtained

Energy Technology Data Exchange (ETDEWEB)

A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

Energy Technology Data Exchange (ETDEWEB)

The paper presents an integrated approach to the problem of electron temperature diagnostics of the plasma in a reversed field pinch. Three different methods, sampling different portions of the electron distribution function, are adopted, namely Thomson scattering, soft X-ray spectroscopy by pulse-height analysis and filtered soft X-ray intensity ratio. A careful analysis of the different sources of systematic errors is performed and a novel statistical approach is adopted to mutually validate the three independent measurements. A satisfactory agreement is obtained over a large range of experimental conditions, indicating that in the plasma core the energy distribution function is well represented by a maxwellian. (author)

International Nuclear Information System (INIS)

The bituminzation of decontamination and ion exchange resin stripping wastes with four grades of asphalt was investigated to determine the effects of asphalt type on the properties of the final products. All waste forms deformed readily under light loads indicating they would flow if not restrained. It was observed in all cases that product leaching rates increased as the hardness of the asphalt used to treat the waste increased. If bituminization is adopted for any Ontario Hydro aqueous radioactive wastes they should be treated with soft asphalt to obtain optimum leaching resistance and mechanical stability during interim storage should be provided by a corrosion resistant container.

International Nuclear Information System (INIS)

In this study, a range of joining technologies has been investigated for creating attachments between refractory metal and Ni-based superalloys. Refractory materials of interest include Mo-47%Re, T-111, and Ta-10%W. The Ni-based superalloys include Hastelloy X and MarM 247. During joining with conventional processes, these materials have potential for a range of solidification and intermetallic formation-related defects. For this study, three non-conventional joining technologies were evaluated. These included inertia welding, electro-spark deposition (ESD) welding, and magnetic pulse welding (MPW). The developed inertia welding practice closely paralleled that typically used for the refractory metals alloys. Metallographic investigations showed that forging during inertia welding occurred predominantly on the refractory metal side. It was also noted that at least some degree of forging on the Ni-based superalloy side of the joint was necessary to achieve consistent bonding. Both ...

International Nuclear Information System (INIS)

We investigate some aspects of the radiation damage mechanisms in biomolecules, focusing on the modelling of resonant fragmentation caused by the attachment of low-energy electrons (LEEs) initially ejected by biological tissues when exposed to ionizing radiation. Scattering equations are formulated within a symmetry-adapted, single-center expansion of both continuum and bound electrons, and the interaction forces are obtained from a combination of ab initio calculations and a nonempirical model of exchange and correlation effects developed in our group. We present total elastic scattering cross-sections and resonance features obtained for the equilibrium geometries of glycine, alanine, proline and valine. Our results at those geometries of the target molecules are briefly shown to qualitatively explain some of the fragmentation patterns obtained in experiments. We further carry out a one-dimensional (1D) modeling for the ...

British Library Electronic Table of Contents (United Kingdom)

Macronutrient self-selection and responses to dietary protein dilution were investigated in Senegalese sole, a flatfish species of interest for Mediterranean aquaculture. Eight groups of six sole were distributed among 75-l tanks and allowed to feed on three experimental diets composed of pure macronutrients: PC (75% crude protein and 25% carbohydrate), PF (75% crude protein and 25% crude fat) and PFC (10% crude protein, 45% crude fat and 45% carbohydrate). Choosing from the above diets, the sole selected a diet containing 68.0% crude protein, 15.7% crude fat and 16.3% carbohydrate. When the PF diet was diluted 50% with cellulose, the fish increased their feed intake to sustain the energy intake (5.0?kJ/kg BW/day). Their selection of fat remained unchanged, while carbohydrate selection sig...

International Nuclear Information System (INIS)

This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning operation for ...

Energy Technology Data Exchange (ETDEWEB)

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.

British Library Electronic Table of Contents (United Kingdom)

The first automated method for the determination of mexiletine hydrochloride - an antiarrhythmic agent - is reported. The method is based on the reaction of the analyte with o-phthalaldehyde (OPA) in the presence of sulfite in basic medium using a sequential injection (SI) manifold. The reaction product was monitored spectrofluorimetrically (lex=350nm/lem=446nm). A simple and effective on-line dilution approach was adopted in order to expand the linearity and apply the method to assay, dosage uniformity and dissolution tests with minimum sample preparation. Chemical (pH, amount concentrations of OPA and sulfite) and instrumental variables (temperature, flow rate, injection volumes, etc.) that affected the determination were studied. The developed assay was validated in terms of linearity, ...

British Library Electronic Table of Contents (United Kingdom)

The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus microplus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000ppm (N10) was the most effective. However, statistical analy...

Energy Technology Data Exchange (ETDEWEB)

Investigations were conducted on the range of emission rates of NO, NO[sub 2], CO and hydrocarbons, and the thermal efficiencies produced by each burner on three production cookers, supplied by different Australian manufacturers. It was found that the emissions and efficiencies were markedly affected by (1) the thermal input, both with and without a load on the burner, and (2) the load-height to flame-length ratio, with a load on the burner. The effect of hydrocarbon leakage into the secondary/dilution air was investigated, to explain the observed correlation of hydrocarbon emission rate with dilution air flow. The hydrocarbons were found to arise from two sources: -leakage from the stabilisation ports at the base of the burner, which was found to be significant at the higher thermal input; -incomplete combustion of the fuel in the premix, which was the dominant source of hydrocarbons emissions at the lower thermal input. (author)

British Library Electronic Table of Contents (United Kingdom)

In this study, the effect of intake charge dilution with carbon dioxide on the combustion and emission characteristics of a 4-cylinder direct-injection diesel engine fueled with biodiesel, ethanol-biodiesel and methanol-biodiesel were investigated. With increase of intake CO"2 concentration, CO, HC, particulate mass concentration, particle number concentration and geometric diameter (GMD) of all fuels increased while NO"x decreased obviously. After addition of methanol and ethanol in biodiesel, the NO"x, particulate mass concentration and particle number concentration decreased at each intake CO"2 concentration, compared with biodiesel. Moreover, as the intake CO"2 concentration increased from 2% to 5.6%, particulate mass concentration of the alcohol-biodiesel blends remained almost unchan...

Energy Technology Data Exchange (ETDEWEB)

The densities and refractive indices of two binary systems (water + MEA and water + MDEA) and three ternary systems (water + MEA + CO{sub 2}, water + MDEA + CO{sub 2}, and water + MEA + MDEA) used for carbon dioxide (CO{sub 2}) capture were measured over the range of compositions of the aqueous alkanolamine(s) used for CO{sub 2} absorption at temperatures from 295 to 338 K. Experimental densities were modeled empirically, while the experimental refractive indices were modeled using well-established models from the known values of their pure-component densities and refractive indices. The density and Gladstone-Dale refractive index models were then used to obtain the compositions of unknown samples of the binary and ternary systems by simultaneous solution of the density and refractive index equations. The results from this technique have been compared with HPLC (high-performance liquid chromatography) ...

Energy Technology Data Exchange (ETDEWEB)

Dose-response studies of the radiosensitivity of spermatogonial stem cells in various epithelial stages after irradiation with graded doses of fission neutrons of 1 MeV mean energy were carried out in the Cpb-N mouse. These studies on the stem cell population in stages IX-XI yielded simple exponential lines characterized by an average D0 value of 0.76 +/- 0.02 Gy. In the subsequent epithelial stages XII-III, a significantly lower D0 value of 0.55 +/- 0.02 Gy was found. In contrast to the curves obtained for stem cells in stages IX-III, the curves obtained in stages IV-VIII indicated the presence of a mixture of radioresistant and radiosensitive stem cells. In stage VII, almost no radioresistant stem cells appeared to be present and a D0 value for the radiosensitive stem cells of 0.22 +/- 0.01 Gy was derived. Previously, data were obtained on the size of colonies (in number of spermatogonia) derived from ...

Science.gov (United States)

The relationship between plasma testosterone levels and locomotor activity in wild-caught sexually mature male meadow voles (Microtus pennsylvanicus) was assessed in the laboratory. Several aspects of locomotor activity were monitored for 1 h on two consecutive days using the automated Digiscan activity monitoring system. Plasma testosterone levels were determined immediately following the second day of activity monitoring. Significant Pearson correlations were obtained between plasma testosterone levels and total distance traveled [r(10) = 0.55, p < 0.05] and amount of time spent in movement [r(10) - 0.55, p < 0.05] on the second day. The wild voles showed a reduction in activity levels from the first to the second day of activity monitoring, which is indicative of habituation to a novel environment. This study provides direct evidence for a significant correlation between laboratory measures of behavioral activity and plasma ...

Energy Technology Data Exchange (ETDEWEB)

The developed electrical networks in the agricultural regions of the Estonian SSR make it possible to construct relatively powerful wind power plants at the sites of the most favorable wind conditions with small outlays for the power transmission lines. The wind power plant electricity can be used to electrify the production processes in agriculture, while the surplus can be supplied to the energy system. The inclusion of the wind power plants in the energy system makes it possible to improve the total generation of energy or reduce the consumption of fuel. With the efficient arrangement of the wind power plants, one can also reduce the energy losses during its transfer. Calculations indicated that in the coastal zones of the Estonian SSR, one can obtain specific power of 420-480 kW/km/sup 2/. For comparison it is indicated that the Estonian SSR in the agricultural regions now uses 8-12 kW/km/sup 2/. The wind-energy ...

UK PubMed Central (United Kingdom)

Some of most used indicators in marine ecology are nucleic acid-derived indices. They can be divided by target levels in three groups: 1) at the organism level as ecophysiologic indicators, indicators...Full Text Available

International Nuclear Information System (INIS)

The high pressure discharges (pulsed or D C corona, barrier, gliding and the others), have been studied both experimentally and theoretically as sources of low temperature plasma for pollution control technologies. The potential of electrical discharge methods has been demonstrated for the decomposition of many types of VOC. The air or oxygen are used as a feed gas in which pollutant is diluted. The ozone production in air or oxygen in such discharges is also discussed

Energy Technology Data Exchange (ETDEWEB)

In Ce(Ru{sub 1-x}Pd{sub x}){sub 2}Si{sub 2} the dilution of the transition metal leads to strong electronic effects resulting in the disappearance and the appearance of long-range magnetic order in CePd{sub 2}Si{sub 2} and CeRu{sub 2}Si{sub 2}, respectively. ((orig.)).

International Nuclear Information System (INIS)

The author is exploring the efficiency of pulsed plasma processing in the removal of nitrogen dioxide, nitrogen oxide, and other pollutants. This process uses an electrical discharge to create chemical radicals from air molecules. These radicals can react with pollutants and form harmless compounds. Additives such as hydrocarbons are also used to improve the efficiency of the removal. The efficient removal of nitrogen dioxide has required the presence of dilute aqueous solution of ammonia.

International Nuclear Information System (INIS)

Neutron activation of nitrogen and hydrogen in the body, the isotope dilution technique and the measurement of naturally radioactive potassium in the body are among the new nuclear methods, now under collaborative development by the Australian Nuclear Scientific and Technology Organization and medical specialists from several Sydney hospitals. These methods allow medical specialists to monitor the patient's response to various diets and dietary treatments in cases of cystic fibrosis, anorexia nervosa, long-term surgical trauma, renal diseases and AIDS. ills.

UK PubMed Central (United Kingdom)

This study evaluates the frequency and functions of immunocompetent T cells at the clonal level in solid human lung tissue versus peripheral blood. Enzymatic digestion of slices of histologically normal...Full Text Available

CERN Document Server

Liquid-liquid wetting failure is investigated in a two-dimensional Couette system with two immiscible fluids of arbitrary viscosity. The problem is solved exactly using a sharp interface treatment of hydrodynamics (lubrication theory) as a function of the capillary number, viscous ratio and separation of scale, i.e. slip length versus macroscopic scale of the system. The existence of critical velocities, above which no stationary solutions are found, is analyzed in detail in terms of the relevant parameters of the system. Comparisons with existing analysis for other geometries are also carried out. A numerical method of analysis is also presented, based on diffuse interface models obtained from multiphase extensions of the lattice Boltzmann equation (LBE). Sharp interface and diffuse interface models are quantitatively compared face to face indicating the correct limit of applicability of the diffuse interface models.

Science.gov (United States)

Swollen basiodiospores of an adenine auxotroph of Phanerochaete chrysosporium were protoplasted with Novozyme 234 and transformed to prototrophy by using a plasmid containing the gene for an adenine biosynthetic enzyme from Schizophyllum commune. Transformation frequencies of 100 transformants per {mu}g of DNA were obtained. Southern blot analysis of DNA extracted from transformants demonstrated that plasmid DNA was integrated into the chromosomal DNA in multiple tandem copies. Analysis of conidia and basiodiospores from transformants demonstrated that the transforming character was mitotically and meiotically stable on both selective and nonselective media. Genetic crosses between double mutants transformed for adenine prototrophy and other auxotrophic strains yielded Ade{sup {minus}} progeny, which indicated that integration occurred at a site(s) other than the resident adenine biosynthetic gene.

Energy Technology Data Exchange (ETDEWEB)

Woven Kevlar fabrics exhibit a number of beneficial mechanical properties which include strength, flexibility, and relatively low density. The desire to engineer or design Kevlar fabrics for specific applications has stimulated interest in the development of theoretical models which relate their effective mechanical properties to specific aspects of the fabric morphology and microstructure. In this work the author provides a theoretical investigation of the large deformation elastic response of a plane woven Kevlar fabric and compares these theoretical results with experimental data obtained from uniaxially loaded Kevlar fabrics. The theoretical analysis assumes the woven fabric to be a regular network of orthogonal interlaced yarns and the individual yarns are modeled as extensible elastica, thus coupling stretching and bending effects at the outset. This comparison of experiment with theory indicates that the deformation of woven fabric can ...

Science.gov (United States)

The aim of this paper is to illustrate the validity and efficiency of iterative methods for solving large linear systems arising from the finite element discretization of the equation governing conduction-controlled solidification processes. Starting from the basic enthalpy equation, two alternative formulations are obtained and fixed-grid finite element discretizations are developed. These discretizations yield a set of nonlinear equations that are linearized using the Newton-Raphson scheme. The linearized equations are used as a basis for evaluating different iterative methods of the conjugated gradient type. Symmetric scaling and incomplete factorization preconditioning of the linear equations are used to improve the convergence properties of the iterative methods. Vectorization and parallelization are also employed to make full use of the CRAY-2 supercomputer. The results indicate that the implementation of currently available iterative ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Acid-treated cobia (Rachycentron canadum) skin was extracted in a retort (121C) to obtain retorted skin gelatin hydrolysates (RSGHs) containing antioxidant peptides with noticeable antioxidant properties. To improve the antioxidant activity of cobia RSGHs, five processing factors including alkali concentration, alkali pretreatment time, phosphoric acid concentration (PC), water/skin ratio (WS) and retorting time (RT) in RSGH production were screened using a fractional factorial design to identify critical factors. It indicated that PC, WS and RT had significant effects on ,-diphenyl--picrylhydrazyl (DPPH) scavenging by RSGHs. Subsequently, the optimization of PC, WS and RT on the DPPH scavenging of RSGHs was studied using a central composite design to collect data that resulted in...

British Library Electronic Table of Contents (United Kingdom)

Corrosion inhibition of iron in H2SO4 by polyacrylic acid (PAA) was investigated using electrochemical techniques at 30degreeC. Results obtained indicate that PAA inhibited the corrosion of iron in the acid medium. Inhibition efficiency increases with increase in PAA concentration and synergistically enhanced on addition of iodide ions. Potentiodynamic polarization results suggest that PAA functions as a modest cathodic inhibitor. The adsorption of PAA onto the iron surface followed Temkin adsorption isotherm. FTIR analysis revealed that the synergistic effect due to co-adsorption of iodide ions and PAA is co-operative in nature.

British Library Electronic Table of Contents (United Kingdom)

The age hardening behavior of Al-4.5%Cu alloy composite reinforced with zircon sand particulates and produced by stir casting route has been investigated in different quenching media viz, water, oil, and salt brine solution (7wt%). Optical microscopy of the as cast alloy composite indicates that the matrix of the composite has the cellular structure. Copper rich CuAl2 precipitates have been found near particle matrix interface. The results of ageing demonstrate that the microhardness of age hardenable Al-Cu based alloy composites depend on the quenching medium in which they are heat treated. Salt brine quenching is faster as compared to water and oil, even if higher strength is obtained but cannot be used for complex shapes and thin sections where oil quenching is the alternative due to mi...

British Library Electronic Table of Contents (United Kingdom)

The influence of selenium dioxide (SeO2) on the microstructure and electrodeposition of manganese coatings obtained from a sulfate based neutral solution was investigated by material characterization methods and electrochemical techniques. The crystal structure and surface morphology of these coatings were studied by scanning electron microscopy (SEM) and powder X-ray diffraction spectroscopy (XRD), respectively. The SEM and XRD data showed that SeO2 could effectively accelerate phase transformation, and facilitate leveled and fine grain growth. The electrochemical results indicated that SeO2 could inhibit hydrogen evolution reaction and promote manganese deposition. The action of selenium dioxide in manganese deposition was found to be a reduction and adsorption mechanism. The process cou...

Science.gov (United States)

We report here results of an application of single-nucleon stripping reactions at high energies (65 MeV/u) in inverse kinematics to obtain spectroscopic factors. From measurements of the partial cross-sections for ground and excited states in residual nuclei formed in one-proton stripping reactions, single particle orbits and occupancies of light nuclei have been studied in the s-d shell. Single proton stripping cross-sections of {sup 25}Al and {sup 26,27,28}P on a Be target have been measured using the S800 spectrograph and the NaI(Tl) array at the NSCL. These results indicate that this technique may provide a general tool for the intermediate energy range analogous to transfer (pick-up) reactions at low-energy.

Energy Technology Data Exchange (ETDEWEB)

A widely used veterinary antibiotic, tetracycline (TC), has been incorporated in Langmuir-Blodgett (LB) films of dipalmitoylphosphatidic acid (DPPA) by means of two different procedures: co-transfer and incubation in solution. The resulting structures were characterized by means of contact angle and ellipsometric measurements. The presence of the antibiotic in the phospholipid film was evidenced by means of UV-Vis electronic absorption and infrared vibrational spectroscopy. The two sets of measurements unambiguously indicated the presence of the drug in the LB layer films obtained with both methods, although incubation led to a smaller content of immobilized tetracycline. In both cases, the drug was found to reside in the hydrophilic portion of the layers due to specific interactions of the dimethylamino group of the molecule with the polar head groups of the phospholipid.

British Library Electronic Table of Contents (United Kingdom)

This paper is dedicated to the treatment of sludge occurring in frame of the Egyptian produced from oil and gas production. The activity levels of three radium isotopes: Ra-226 (of U-series), Ra-228 and Ra-224 (of Th-series) in the solid TENORM waste (sludge) were first evaluated and followed by a sequential treatment for all radium species (fractions) presented in TENORM. The sequential treatment was carried out based on two approaches `A' and `B' using different chemical solutions. The results obtained indicate that the activity levels of all radium isotopes (Ra-226, Ra-228 and Ra-224) of the environmental interest in the TENORM waste sludge were elevated with regard to exemption levels established by IAEA [International Atomic Energy Agency (IAEA), International basic safety standards f...

International Nuclear Information System (INIS)

The Operation Technical Specifications is a document that is attached to the Operation License of a nuclear power station and its are applicable since the first load of fuel begins in the reactor core. This document is normative and with its application it is assured the safe operation of the nuclear power station. For the case of the Laguna Verde Nucleo electric Central this is documented in the Condition No. 5 of the License of Operation. Any modification to the ETOs is subject to the evaluation by part of the regulator organism. This work describes the regulator frame and the evaluation process of the Improved Technical Specifications on the part of the regulator organism. It is also indicated the implementation process of the improved ETOs and the main characteristics and benefits that are obtained of these processes to maintain the safety of the nuclear power stations. (Author)

CERN Document Server

Monte Carlo calculations of proton irradiation of permanent magnets for the TRADE experiment have been performed. An irradiation dose of about 4´106 Gy/yr/mA has been estimated due to beam losses in normal operating conditions. Existing experimental results indicate that this irradiation level may induce a considerable demagnetization: in fact, a dose of 6´107 Gy induces a remanence loss of 0.3 % on samples of Sm2Co17 magnets, which are the most resistant type. More detailed calculations with the final design of the magnets and of the beam line are suggested, to determine if the irradiation levels allowed a reliable operation of the permanent magnets for the entire duration of the TRADE experiment. Damage and gas production rates have also been calculated; the values obtained are very low, thus confirming that the demagnetization process is in great part reversible.

International Nuclear Information System (INIS)

This pilot project was carried out for the purpose of testing methods for active biological monitoring. It covered a period of three years (until September 1994), including two years of exposure. The measurements served to determine pollutant levels in plants used as animal fodder and dust-borne heavy metal concentrations in different sites and, on this basis, to obtain indirect information on human exposure. Among others, the pilot project investigated the suitability of Italian rye-grass as a biological indicator for aluminium, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, magnesium, manganese, nickel, lead, platinum, antimony, titanium, and zinc. (orig./GL).

Energy Technology Data Exchange (ETDEWEB)

Turbulent premixed methane-air combustion in a cylindrical chamber is numerically simulated considering radiation effect. Reaction rates are considered as minimum rates between Arrhenius rates and eddy break up rates. A five step reduced mechanism is used. Turbulent modeling is done via standard k-{epsilon} model imposed by empirical inlet boundary conditions. Source terms of energy equation consist of reaction rates and radiation effects. The discrete ordinate method (DOM) is employed to solve the radiative transfer equation (RTE) and the weighted sum of gray gas model (WSGGM) is imposed to consider radiation effect of non-gray gases. The results indicate that in the case of turbulent combusting flows, the effect of radiation of gases can affect the temperature and species concentrations. The numerical results obtained considering radiation effect are closer to the experimental data than that of the case without radiation effect. (author)

International Nuclear Information System (INIS)

A wood-polymer composite has been produced by impregnating the wood with the monomer and subsequently polymerizing it by exposure to a gamma radiation source. To compare the improvement in creep deformation of the wood due to the polymer impregnation, a nonlinear Norton-Bailey isothermal mathematical function has been used to model the bending creep deformation of the wood-polymer composites. Results show that the impregnation significantly improves the creep resistance of the wood. The maximum creep resistance is obtained when the amount of polymer impregnation exceeds about 30%. An interfacial interaction between the wood cell wall and the polymer could explain the creep deformation improvement, as well as the maximum impregnation level beyond which little improvement occurs. The results indicate that polymer impregnation is a viable method for improving the poor creep properties of wood. (author).

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the mathematical model developed by Sunu and Bennion that has been extended to include the separator, precipitation of both solid ZnO and K{sub 2}Zn(OH){sub 4}, and the air electrode, and has been used to investigate the behavior of a primary Zn-Air battery with respect to battery design features. Predictions obtained from the model indicate that anode material utilization is predominantly limited by depletion of the concentration of hydroxide ions. The effect of electrode thickness on anode material utilization is insignificant, whereas material loading per unit volume has a great effect on anode material utilization; a higher loading lowers both the anode material utilization and delivered capacity. Use of a thick separator will increase the anode material utilization, but may reduce the cell voltage.

Energy Technology Data Exchange (ETDEWEB)

X-ray photoelectron spectroscopy measurements indicate that the Ce{sup 3+} like fraction in {gamma}-Al{sub 2}O{sub 3} supported CeO{sub 2} can be decreased by the incorporation of La{sup 3+}. If La{sup 3+} is incorporated into the {gamma}-Al{sub 2}O{sub 3} before CeO{sub 2} is added, a higher CeO{sub 2} dispersion and a greater range of reversible reducibility of the CeO{sub 2} may also be obtained. These changes offer potential for improvement in the oxygen storage capacity provided by CeO{sub 2} in three-way catalysts. The actual effect of La{sup 3+} incorporation on the activity and durability of a Pt catalyst is assessed by a combination of temperature programmed reduction and flow reactor measurements.

International Nuclear Information System (INIS)

Two small craters (number 74, 119 microns, and number 31, 158 microns in diameter) with depth to diameter ratios of about 0.59 and 0.8, respectively, were found in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11EOOF. Both craters have residues concentrated in the crater bottoms, along the walls, and on top of the overturned rims. Low voltage scanning electron electron microscopy, Auger electron spectroscopy, time of flight secondary ion mass spectroscopy and energy dispersive x-ray spectroscopy were used to obtain high resolution imagery and elemental analysis. Analyses indicate that the impactor for both craters was carbon-rich, as the residues contain mostly C. Silicon, S, and F in low concentrations are present on the Al surface away from the craters and may be, in part, contaminants.

British Library Electronic Table of Contents (United Kingdom)

The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can b...

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

Energy Technology Data Exchange (ETDEWEB)

A new fuel-cell electrocatalyst based on highly porous carbonized polyacrylonitrile (PAN) microcellular foam with platinum particles was prepared recently in this laboratory. Its surface morphology, one of the most important aspects of a practical electrocatalyst, has been examined in terms of fractal theory and methods. The fractal dimension of the platinum particles dispersed in porous carbonized PAN foam was determined by using chronometric and rotating-disk-electrode methods in oxygen-saturated solutions. A fractal dimension smaller than 2 was obtained, which was attributed to the partially active nature of the surface of this electrocatalytic material. This value of fractal dimension is also proposed to be considered as a reaction dimension. A reaction dimension smaller than 2 may indicate that not all of the platinum particle surface is accessible to the incoming oxygen molecules.

CERN Document Server

We consider the exact path sampling of the squared Bessel process and some other continuous-time Markov processes, such as the CIR model, constant elasticity of variance diffusion model, and hypergeometric diffusions, which can all be obtained from a squared Bessel process by using a change of variable, time and scale transformation, and/or change of measure. All these diffusions are broadly used in mathematical finance for modelling asset prices, market indices, and interest rates. We show how the probability distributions of a squared Bessel bridge and a squared Bessel process with or without absorption at zero are reduced to randomized gamma distributions. Moreover, for absorbing stochastic processes, we develop a new bridge sampling technique based on conditioning on the first hitting time at zero. Such an approach allows us to simplify simulation schemes. New methods are illustrated with pricing path-dependent options.

International Nuclear Information System (INIS)

The present invention concerns a method of evaluating corrosion resistance of a zirconium alloy easily and in a short period of time. An anode polarization curve of the zirconium alloy is measured to obtain an anode polarization curve expressed by logarithm. The curve is converted to a potential-current density curve expressed by absolute values. The peak area in the curve of the converted potential-current density is indicated by numerical values. Further, the corrosion resistance of the zirconium alloy is evaluated based on the peak area converted into the numerical values as a reference. This method is based on the finding that the peak area has a close relation with nodular corrosion resistance, and the corrosion resistance can be judged with respect to a specific zircaloy-2. (T.M.).

International Nuclear Information System (INIS)

The intermediate valent behaviour of YbPd_2Si_2 has been studied under pressure in the temperature range from 1.2 K to 90 K by using the 84 keV Moessbauer transition in "1"7"0Yb. At 54 kbar and 4.2 K we obtain an increase of the electric field gradient (EFG) by a factor of #approx =# 3. In addition, the EFG varies strongly with temperature, in contrast to the behaviour at ambient pressure. At 1.2 K a change of the hyperfine pattern is observed indicating a magnetic character of the Yb ion. These results provide evidence of a pressure induced change of the valence state close to 3+. (orig.).

International Nuclear Information System (INIS)

The intensity of superstructure reflections and associated diffuse scattering from In_0_._5Ga_0_._5P and In_0_._5Al_0_._5P epitaxic layers grown on (001) GaAs substrates was mapped in reciprocal space. The Warren-Cowley short-range-order parameters were obtained through the usual process for evaluating Fourier coefficients. Varying values for the correlation length in different directions indicate how group III atoms stack up in ordered states. The resultant structure with long-range order confirms the hypothesis made on the basis of electron diffraction and high-resolution transmission electron microscopy studies. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Possible accident scenarios for a fusion reactor include breaches in the vacuum or cooling system. Intruding air or steam could react with structural or plasma facing materials, possibly mobilizing radioactive isotopes. Safety assessments must consider the early dose at the site boundary from the release of these activated materials. Previous calculations have indicated that cobalt isotopes dominate dose calculations for designs using stainless steel. Values used in these calculations, however, had been largely determined by the measurement limits of the chemical analysis methodology instead of measured releases. The purpose of the current study was to refine the analytical method to reduce the limit for detecting cobalt, and then test PCA steel in air and steam between 973 and 1473 K. Goals were to obtain more accurate measurements of cobalt mobilization in terms of g/m{sup 2}{center_dot}h and insight into the mobilization mechanisms.

International Nuclear Information System (INIS)

The phase separation of (water + salt + polyethylene glycol 15000) systems was studied by cloud-point measurements using the particle counting method. The effect of three kinds of sulphate salt (Na2SO4, K2SO4, (NH4)2SO4) concentration, polyethylene glycol 15000 concentration, mass ratio of polymer to salt on the cloud-point temperature of these systems have been investigated. The results obtained indicate that the cloud-point temperatures decrease linearly with increase in polyethylene glycol concentrations for different salts. Also, the cloud points decrease with an increase in mass ratio of salt to polymer.

International Nuclear Information System (INIS)

We have studied the structure of both propanol isomers in their glassy and crystalline states by neutron diffraction. The glass-transition temperatures of 1- and 2-propanol are about 98 and 115 K, respectively and, surprisingly, even larger differences are observed for the melting temperatures of the stable crystals, which are 148 and 185 K, respectively. Their supercooled liquid phases show rather different relaxation spectra, 1-propanol manifesting strong deviations from Debye behavior, whereas 2-propanol shows a far weaker effect. We discuss the spectra obtained for the static structure factor and the static pair correlation function D(r). There is a noticeable difference in the position of the first sharp diffraction peak, which clearly indicates a density change, well correlated with the period of the intermolecular oscillations shown by D(r). (orig.)

Energy Technology Data Exchange (ETDEWEB)

AZ31 Mg alloy samples were extruded by an equal channel angular extrusion (ECAE) process and subsequently annealed to obtain fine-grained material with a low dislocation density. Tensile tests at room temperature exhibited an apparent steady-state deformation region and a large tensile elongation of 47%. The deformed microstructure at an elongation of 2% indicated a substantial cross-slip to nonbasal planes possibly induced by grain-boundary compatibility effects. The nonbasal segments of dislocations were found to consist of 40% of the total dislocation density at a yield anisotropy factor of only 1.1 instead of an expected value of 100 from single-crystal experiments. (orig.)

International Nuclear Information System (INIS)

A nodal integral method is derived for the monoenergetic, steady-state, fixed source neutron diffusion equation in hexagonal geometry based on a coordinate transformation that maps a parallelogram into a rectangle. The new hexagonal nodal diffusion method is implemented in the computer code HND where the discrete-variable equations are solved via an iterative scheme. Because the new method's equations are derived for a rhombus, they can be solved on a sequence of embedded meshes to study the method's error order. Indeed a preliminary numerical error analysis reveals a second-order error in the mesh size, and comparison with finite difference results obtained with the finite difference based BOLD-VENTURE code indicate the superior accuracy of our new nodal method.

British Library Electronic Table of Contents (United Kingdom)

From the COMBO-17 digital sky survey data, 1,231 faint blue galaxies with photometric redshifts of 0.1obtained respectively by using only optical data and by using both optical and near-infrared data. The results indicate that there are 183 galaxies whose photometric redshifts derived from both optical and infrared data are greater than 1.2, that the rms error of the derived photometric redshifts is 0.046, and that to increase the photometric SNR is also helpful for discriminating those misjudged low-redshift galaxies by using only the optical data. We have studied a...

International Nuclear Information System (INIS)

In this study, the degrees of destruction of hemoglobin irradiated in atmospheres of air and argon were compared. Hemoglobin preparations were irradiated in the forms: oxyhemoglobin (HbO_2) deoxyhemoglobin (Hb"2"+) and methemoglobin (MetHb) applying doses of 0.5 to 5 Mrad. The degree of hemoglobin destruction was estimate on the basis of changes in the values of the absorption coefficient at the Soret band, the absorption ratio A_5_0_5/A_5_6_3 determined after conversion of irradiated preparations into MetHb, absorption coefficinets for pyridine hemochromogen obtained from irradiated preparations, and changes in parameters characterizing the hemoglobin oxygenation reaction (log p/sub 1/2/O_2 and the Hill n coefficient). The calculated oxygen enhancement ratios S were generally higher than 1 for the parameters estimated. This indicates that the presence of oxygen during irradiation enhances hemoglobin destruction.

DEFF Research Database (Denmark)

The syntheses of N-alkylated deoxynojirimycin and 1,5-dideoxy-1,5-iminoxylitol derivatives having either a D- or an L-erythritol-3-sulfate functionalized N-substituent are reported. The alkylating agent used was a cyclic sulfate derivative, whereby selective attack of the nitrogen atom at the least hindered primary center afforded the desired ammonium salt. In aqueous solution, these salts were configurationally labile at the ammonium center. Sulfonium and/or selenonium analogues of the ammonium salts were prepared by analogous reactions. The chalcogen salts were obtained as mixtures of diastereomers, separable in some cases, differing only in the stereochemistry at the configurationally stable sulfur or selenium atoms. Proof of configuration and conformation of each compound was obtained by detailed NMR experiments. The compounds are six-membered ring analogues of salacinol, a known sulfonium-salt glucosidase inhibitor. Evaluation of the ...

Energy Technology Data Exchange (ETDEWEB)

The LiMnO{sub 2} lamellar oxide, obtained by exchange reaction from its sodium homologue {alpha}-NaMnO{sub 2}, has been used as a positive electrode for lithium batteries. After the first electrochemical cycle, the shape of the potential-composition curve changes and indicates a change in the structure. This modification changes imperceptibly at each cycle and after about 40 cycles, a stationary state is reached. Powder spectra refinement using the Rietvelt method shows a migration of manganese ions from the thin sheets towards the inter-sheet space. After a single cycle, 8% of the manganese ions are already present in the lithium site and this rate reaches 13% after 3 cycles. During long cycling, a redistribution of ions and vacancies inside the cfc oxygenated pile leads to a structure very similar to the LiMn{sub 2}O{sub 4} spinel. This structure evolution is to be compared with the one obtained from the orthorhombic ...

Energy Technology Data Exchange (ETDEWEB)

Simplifying hypotheses are required when combustion and aerodynamic phenomena are considered simultaneously. In this paper, a turbulent combustion model is proposed, in which the combustion chemistry is reduced to a single reaction. In this way, only two variables are needed to describe the problem and combustion can be characterized by the consumption of one of the two reactive species. In a first step, the instantaneous consumption rate is obtained using the Lagrangian form of the mass fraction equation of the species under consideration, and by considering the equilibrium state only. This state is determined in order to preserve the consistency with results that should be obtained using a complete kinetics scheme. In a second step, the average rate is determined using the instantaneous consumption term and a probabilistic density function. This model was tested on various configurations and in particular on an experimental main chamber and ...

International Nuclear Information System (INIS)

Propylene polymerizations were carried out with #phi#_2C(Flu)(Cp)ZrCl_2 and SiMe_2(Ind)2ZrCl_2 catalysts supported on silica, zeolite sodic mordenite (NaM) and acid mordenite (HM). The polymerizations were performed at different temperatures and varying aluminium/zirconium molar ratios ([Al]/[Zr]). The effect of these reaction parameters on the catalyst activity was investigated using a proposed statistical experimental planning. In the case of f_2C(Flu)(Cp)ZrCl_2, SiO_2 and NaM were used as support and the catalyst performance evaluated using toluene and pentane as polymerization solvent. The molecular weight, molecular weight distribution, melting point and crystallinity of the polymers were examined. The results indicate very high activities for the syndiospecific heterogeneous system. Also, the polymers obtained had superior Mw and stereo regularity. (author)

International Nuclear Information System (INIS)

Ionic motion of a divalent cation, Ba"2"+, in a single crystal of Ba-Al-priderite was studied using "2"7Al as an NMR probe. Several pairs of satellite peaks due to electric quadrupole interaction were observed superposed on broad satellite tails on both sides of the main peak of "2"7Al. These peak pairs indicate the existence of some stable three-dimensional configurations of Ba"2"+ ions in the structure, and the broad shoulders show a random substitution of Al"3"+ for Ti"4"+ sites. The temperature dependence of the spin-lattice relaxation time T"*_l measured in the temperature range from 161 to 1176 K was analyzed by a curve fitting method on the assumption that there are two types of Ba"2"+ ions. An activation energy of 0.47 eV was obtained for the motion of Ba"2"+ ions which are easy to move, and a broad distribution of activation energies spread over a range from 0.95 to 2.45 eV was obtained for the motion of Ba"2"+ ...

Energy Technology Data Exchange (ETDEWEB)

A novel method to detect and correct inaccuracies in a set of unconstrained dense correspondences between two images is presented. Starting with a robust, general-purpose dense correspondence algorithm, an initial pose estimate and dense 3D scene reconstruction are obtained and bundle-adjusted. Reprojection errors are then computed for each correspondence pair, which is used as a metric to distinguish high and low-error correspondences. An affine neighborhood-based coarse-to-fine iterative search algorithm is then applied only on the high-error correspondences to correct their positions. Such an error detection and correction mechanism is novel for unconstrained dense correspondences, for example not obtained through epipolar geometry-based guided matching. Results indicate that correspondences in regions with issues such as occlusions, repetitive patterns and moving objects can be identified and corrected, such that a more ...

Science.gov (United States)

A knowledge of surface film growth kinetics can be quite useful in the production of materials for uses ranging from protective coatings to microelectronic devices. A technique for determining the kinetics of film growth is presented which should prove to be a valuable alternative to the array of spectroscopies (AES, RBS, etc.) currently favored for these measurements. Some of the virtues of this X-ray diffraction approach are its non-destructive nature, thickness resolution better than 50 {angstrom} and conventional equipment requirements. Results obtained for the growth of Pd{sub 2}Si films during thermal annealing of Pd coatings on Si, indicate parabolic growth over a temperature range of 160-222 C. The rate constant was found to be k{prime} = 7 {times} 10{sup {minus}4} exp ({minus}1.06 eV/kT) cm{sup 2}/sec, where (film thickness){sup 2} = k{prime} x time. This activation energy is in agreement with results obtained by ...

Energy Technology Data Exchange (ETDEWEB)

This study effort was required as a preliminary step prior to initiation of field measurements of atmospheric dispersion in coastal regions. The Nuclear Regulatory Commission (NRC) is in the process of planning an extensive field measurement program to generate data which will serve as improved data bases for licensing decisions, confirmation of regulations, standards, and guides, and for site characterizations. The study being reported here is an effort directed to obtaining as much information as is possible from existing studies that is relevant toward NRC's objectives. For this study, reports covering research and meteorological measurements conducted for industrial purposes, utility needs, military objectives, and academic studies were obtained and critically reviewed in light of NRC's current data needs. This report provides an interpretation of the extent of existing usable information, an ...

International Nuclear Information System (INIS)

The bioavailability of lead was studied in rats fed various baby foods (Babymix-turkey, Babymix-vegetables, Frutolino-fruit, Frutamix-bananas, Babyron-S-26, Truefood), cow's milk, bread, liver and standard rat diet. Lead absorption was determined by measuring the whole body retention of "2"0"3Pb 6 days after a single oral application. Highest absorption values ranging from 17 to 20% were obtained in animals fed cow's milk and fruit foods. Rats on other human diets absorbed between 3 and 8% of the radioactive lead dose. Only in animals on rat diet lead absorption was below 1%. It is concluded that rats fed human diets show absorption values similar to those in humans. This might indicate that the bioavailability of lead is primarily dependent on dietary habits. This experimental model, if confirmed by further work, might be useful for obtaining preliminary data on the bioavailability of metals from various foods.

International Nuclear Information System (INIS)

In this paper, we report on the analysis of reverse flow in inverted U-tubes of a steam generator under natural circulation condition. The mechanism of reverse flow in inverted U-tubes of the steam generator with natural circulation is graphically analyzed by using the full-range characteristic curve of parallel U-tubes. The mathematical model and numerical calculation method for analyzing the reverse flow in inverted U-tubes of the steam generator with natural circulation have been developed. The reverse flow in an inverted U-tube steam generator of a simulated pressurized water reactor with natural circulation in analyzed. Through the calculation, the mass flow rates of normal and reverse flows in individual U-tubes are obtained. The predicted sharp drop of the fluid temperature in the inlet plenum of the steam generator due to reverse flow agrees very well with the experimental data. This indicates that the developed mathematical model and ...

Energy Technology Data Exchange (ETDEWEB)

Bone images obtained by single exposure dual energy subtraction with computed radiography, a new image processing method, were evaluated for the detectability of calcification in lung nodules in both phantom and clinical studies. In the phantom study, five simulated nodules containing known and uniformly distributed amounts of calcium hydroxide were placed in a human chest phantom and images were obtained the following five techniques: (1) conventional radiography (CXR), (2) low kV conventional radiography (Low), (3) Fuji computed radiography (FCR), (4) bone images with conventional singles exposure energy subtraction (ES) and (5) bone image with fine single exposure energy subtraction (FES). The detectability of calcification in the simulated nodules was evaluated by six radiologists using ROC analysis and two-way analysis of variance. In the clinical study, images of 42 lung nodules (21 calcified lung nodules and 21 non-calcified nodules), in ...

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The pharmacology of the alpha-2 adrenoceptor of the human adipocyte was improved by using some new alpha-2 antagonists from different chemical families (imidazolines, benzazepines and benzofuroquinolizines) in biological and binding assays. Moreover, investigations were also carried out to define the binding properties of a new imidazolinic antagonist, RX821002 (2-(2-methoxy-1,4-benzodioxan-2yl)-2-imidazoline), which could be a potential radioligand. (3H)RX821002 binding was very rapid and reversible. Saturation isotherms indicated that (3H)RX821002 labeled, with high affinity, a homogeneous population of noninteracting binding sites with a mean Kd of 0.98 +/- 0.05 nM (n = 6). The binding of (3H)RX821002 on the human fat cell alpha-2 adrenoceptor displayed a specificity which is strictly similar to that obtained with (3H)rauwolscine and which is classical for an alpha-2 A adrenoceptor. The binding parameters of (3H)RX821002 were compared with ...

International Nuclear Information System (INIS)

FT-IR spectra of the products obtained in each step of the tetramethyltin (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 and TMT/Al_2O_3-SiO_2 system preparation are presented and discussed. The obtained spectra show that TMT reacts with alumina-silica hydroxyl groups already at room temperature, yielding surface methyltin compounds; NH_4ReO_4 reacts with alumina-silica surface at temperatures up to 423 K, yielding rhenium surface species and ammonia, which is strongly bonded by acidic sites of the Broensted kind. FT-IR spectrum of the system (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 indicated the absence of surface methyl tin compounds observed on the surface system TMT/Al_2O_3-SiO_2 , and the presence of physically adsorbed TMT; after 5 h of evacuation of the TMT/3-wt.% Re_2O_7/Al_2O_3-SiO_2 system, the FT-IR spectrum indicated the presence of only a single band at 2977 cm"-"1, which may be assigned to the C-H bond ...

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) has been developing a nuclear waste disposal facility, the Waste Isolation Pilot Plant (WIPP), located approximately 42 km east of Carlsbad, New Mexico. The WIPP is designed to demonstrate the safe disposal of transuranic wastes produced by the defense nuclear-weapons program. Pefiormance assessment analyses (U.S. DOE, 1996) indicate that human intrusion by inadvertent and intermittent drilling for resources provide the only credible mechanisms for significant releases of radionuclides horn the disposal system. These releases may occur by five mechanisms: (1) cuttings, (2) cavings, (3) spallings, (4) direct brine releases, and (5) long- term brine releases. The first four mechanisms could result in immediate release of contaminant to the accessible environment. For the last mechanisq migration pathways through the permeable layers of rock above the Salado are important, and major emphasis is placed on the Culebra Member of the ...

Energy Technology Data Exchange (ETDEWEB)

The use of medicinal plants in the treatment of diseases has increased significantly in the last years, as has research concerning chemical characterization of these plants. In this study, inorganic constituents were determined in leaves and in extracts from three medicinal plant species of the Casearia genus (C. sylvestris, C. decandra and C. obliqua) collected in distinct regions of the Atlantic Forest, SP. The elemental compositions of the soils in which these plants were grown were also determined. Traditionally, these plants are used due to their antiinflammatory, antiacid, antiseptic and cicatrizing properties. The antiulcer and the antitumor activities of the Casearia genus and its capacity to neutralize snake and bee venoms, have also been scientifically confirmed. The analytical methodology used was neutron activation analysis. Long and short irradiation periods of the samples and the standards were carried out at IPEN's IEA-R1 nuclear research reactor. In the leaf K ...

International Nuclear Information System (INIS)

A dilute tungsten heavy alloy consisting of 50W-35Ni-15Fe (wt pct) was liquid phase sintered at 1,500 C for times ranging from 30 to 960 minutes. This alloy corresponds to a nominal solid content of 20 vol pct at the sintering temperature. Because of the excess liquid, the alloy densified easily and exhibited extensive liquid-solid separation due to the density difference between the phases. The solid content at the compact bottom ranged from 45 to 70 vol pct over position and time. The microstructure of the settled region was quantified for volume fraction of tungsten, grain size, connectivity, and settled solid angle of repose. These results provide a basis for extending the microstructural parameters to possible microgravity conditions. The grain growth rate constant varies with the inverse 2/3 power of the volume fraction of liquid, possibly reflecting combined coalescence and solution-reprecipitation processes. This volume-fraction effect on the ...

International Nuclear Information System (INIS)

Liquid-liquid extractive separation of lithium isotopes was carried out in order to investigate the fluctuation of separation factors (a) as a function of salt concentrations in an aqueous phase. Two equations for separation factor (a_o_b_s) as a function of the concentration were introduced; one for the diluted region, and another for the concentrated region. In the former solution where hydrated lithium ions are predominant, 1n a_o_b_s = Ac + B, and in the latter where ion-pairs with anions are predominant, 1n a_o_b_s = Dc + E(c - F)"1"/"3 + G. Some guidelines are derived from the salt-specific constants A, B, D, E, F and G. The heavier isotopes are inclined to be in the more hydrated state in the diluted solution, while the lighter isotopes tend to be in a less hydrated state. In the concentrated solution, heavier isotopes are more likely to be in ion-pair form. Ionic association occurs from the lower concentration in the order of LiI < ...

Energy Technology Data Exchange (ETDEWEB)

In order to investigate the effect of humidity on laminar burning velocity(S), the effect of humidity on the combustion reaction and radiation intensity was studied, taking account of dilution gases such as CO/sub 2/ and Ar which has the approximately identical characteristics to exhaust gas circulation(EGR) gas used to prevent NOx discharge from engines. According to the heat reaction theory, mean specific heat(C) of mixture, mean molecular weight(M) and adiabatic flame temperature(T) etc. were said to affect S but from experimental results, the effect of M and C could be ignored, compared with the effect of T. The relationship between S and H/sub 2/O, Ar of CO/sub 2/% in mixture of diluted gases was clarified. The effect of H/sub 2/O on S was mainly caused by changes of T. The effect of radical C/sub 2/, CH and OH on radiation intensity was similar to that of H/sub 2/O and Ar and the effect of H/sub 2/O on combustion was found only to be the ...

Energy Technology Data Exchange (ETDEWEB)

In this report, we outline the progress achieved in two distinct under the DOE-sponsored cross section project: the initial results obtained from the pulsed 14 MeV neutron facility, and a cooperative effort with Argonne National Laboratory in the measurement of fast neutron cross sections in yttrium. In the 14 MeV neutron laboratory, this year has seen the maturation of the project into one in which initial scattering measurements are now underway. We have improved the accelerator and ion source in several significant ways, so that neutron intensities have now been proven to be adequate for our series of elastic scattering angular distribution measurements outlined in our initial proposal of two years ago. We have successfully tested all components of the time-of-flight spectrometer and recorded initial neutron spectra from the ring targets that we have obtained for our first angular distribution measurements. Examples of the time-of-flight ...

Energy Technology Data Exchange (ETDEWEB)

To determine a suitable combination of X-ray filter and tube kilovoltage for Fuji Computed Radiography (FCR), provide better detection of pulmonary nodules, and reduce patient exposure, we compared observer performance with different X-ray filters and tube voltages. Radiographs were obtained with a copper filter backed by aluminium, with a tungsten filter backed by yttrium and aluminium, and with a lead filter backed by yttrium and aluminium, at both 100 kVp and 135 kVp. Observer performance in detecting simulated lung nodules, which were placed on the posterior aspect of a chest phantom, was compared using receiver operating characteristic (ROC) techniques for each combination of the X-ray filter and tube voltage. The results of the study indicated that (1) nodule detection was superior for the images obtained with 135 kVq as compared with 100 kVp; (2) approximately equal detection rates were obtained ...

International Nuclear Information System (INIS)

Analysis by gas chromatography-mass spectrometry and high performance liquid chromatography has revealed organic residues in sup(99m)Tc-pertechnetate obtained from "9"9Mo-molybdate by extraction, using the organic solvent methylethylketone (MEK). The organic residues have been identified as either (i) low molecular weight carbonyl compounds such as formaldehyde, acetaldehyde and acetone, presumably caused by the effects of #gamma#-radiation on MEK, or (ii) condensation products resulting from the action of strong alkali on MEK during the extraction process. The quantities of organic residues varied from batch to batch of extracted pertechnetate; up to 40 #mu# mL"-"1 was found. When these compounds were tested, in rats, by addition to a pyrophosphate bone-seeking radiopharmaceutical, the tissue distribution was not significantly different from that in the control, which contained no added compound. Assay for "9"9Tc in MEK-derived pertechnetate ...

Science.gov (United States)

Glucoamylase and pullulanase were immobilized on reconstituted bovine-hide collagen membranes using the covalent azide linkage method. A pretanning step was incorporated into the immobilization procedure to enable the support matrix to resist proteolytic activity while accommodating an operating temperature of 50 degrees C. The immobilized glucoamylase and pullulanase activities were 0.91 and 0.022 mg dextrose equivalent (DE) min(-1) cm(-2) of membrane, respectively. Immobilized glucoamylase had a half-life of 50 days while the immobilized pullulanase had a half-life of 7 days. This is a considerably improved stability over that reported by other researchers. The enzymes were studied in their free and immobilized forms on a variety of starch substrates including waxy maize, a material which contains 80% alpha-1-6-glucosidic linkages. Substrate concentrations ranged from 1% to a typical commercial concentration of 30%. Conversion efficiencies of 90-92% DE were ...

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

We discuss how magnetic phenomena affect superconductivity in simple metals, transition metals and alloys thereof, and dilute Rare-Earth alloys. It is shown both qualitatively and quantitatively that superconductors are sensitive probes for studying itinerant spin excitations, local spin excitations associated with nearly magnetic impurities, the effect of the atomic environment on the stability of local magnetic moments, and the nature of the spin order in Rare-Earth alloys. Also, we discuss how magnetic impurities can be used to study the electronic configuration which is responsible for superconductivity in Laves-phase crystals like A-15 compounds and ..beta..-W crystals, for example.

Energy Technology Data Exchange (ETDEWEB)

XVTa and XXTa nuclei were oriented at low temperature as dilute impurities in Fe. The magnetic hyperfine splitting frequencies = B sub(HF)/Ih of the XVTa and XXTa ground states have been measured to be 320.45(11) and 317.552(55) MHz by using the technique of NMR-ON. Taking the known hyperfine field of Y Ta in Fe, the magnetic moments have been deduced: ( XVTa, 7/2 ) =2.270(45) and ( XXTa, 7/2 ) =2.250(45) sub(N). These values of the magnetic moments are discussed in the framework of the rotational model.

Energy Technology Data Exchange (ETDEWEB)

Scientists of the Institute of Wood Chemistry of the Latvian Academy of Sciences have developed two highly efficient processes for producing furfural, a feedstock for varnishes, synthetic resins and plastics. It is made of production wastes, including branches and small-dimension timber. By one process, the raw material is chipped, treated first with diluted sulphuric acid and then with steam heated to 250 degrees C. The other uses concentrated sulphuric acid as a catalyst. Besides furfural, this process also yields sugar solutions used in alcohol and nutrient yeast production.

Energy Technology Data Exchange (ETDEWEB)

The discovery of nearly sixty molecules, often unstable or complexes, in the interstellar space has been one of the greatest surprises of contemporary astronomy. We may, indeed, be surprised that molecules having up to 13 atoms might be synthetized in an extremely diluted space and at a very low temperature. That these molecules are, most of all, organic molecules is another astonishing subject, at least for the non-specialist. The interstellar molecule formation is indeed well understood nowadays, at least for the simplest ones. This article takes stock of interstellar chemistry which is essentially an ionic chemistry very different from laboratory chemistry.

Energy Technology Data Exchange (ETDEWEB)

This work is the first active crossflow filter testing of the new strontium-permanganate process for Envelope C at the Savannah River Technology Center. Extreme filtration difficulties with the ferric hydroxide precipitation led to investigations of other chemistries with simulants. The current process includes the isotopic dilution by precipitation from inactive strontium nitrate addition. A permanganate strike to replace ferric reagents was found to provide practical filterability and good lanthanide or transuranic decontamination. That work had been supported with simulant and active beaker testing.

International Nuclear Information System (INIS)

Eighty-seven subtraction images of FCR were compared with subtraction images of conventional angiography. Although FCR images with reduced exposure dose (25 % of regular dose) and with diluted contrast material (150 mgI/ml, 50 % of usual concentration) were slightly inferior to the images of conventional angiography, most clinically important vessels were adequately visualized. As FCR has wider dynamic range and higher contrast resolution than conventional angiography, FCR may take over conventional angiography. (author).

Energy Technology Data Exchange (ETDEWEB)

Exhaust fine and ultra fine particle numbers, particle sizes, mass, shape, structure and density were studied from Euro II - EEV emission level heavy-duty vehicles. For total particle emission factors city buses were run on dynamic conditions simulating city bus driving. The new heavy-duty chassis dynamometer of VTT was used. Vehicles were a comprehensive sample of current city bus fleet, the type approved emission level of which was Euro II - Euro III. Also cleaner engines of Euro IV to EEV targeted emission level were included: CRT, CNG, DPF. Particle emissions of these buses were extremely low; numbers 1/100 - 1/1000 and masses 1/10 - 1/100 of those of the predominating techniques. Morphological properties of fine particle populations that represent majority of particle size distribution (Da < 500 nm) are being analyzed by image processing (Matlab) from electron microscopical images (SEM, ESEM and TEM) as a function of particle size. Particles from different formation ...

International Nuclear Information System (INIS)

Organizational risk indicators are proposed as a tool for risk control during operation of offshore installations, as a complement to QRA-based indicators. An organizational factor framework is developed based on a review of existing organizational factor frameworks, research on safety performance indicators, and previous work on QRA-based indicators. The results comprise a qualitative organizational model, proposed organizational risk indicators, and a quantification methodology for assessing the impact of the organization on risk. The risk indicators, when validated, will aid in a frequent control of the risk in the periods between the updating of the quantitative risk assessments.

International Nuclear Information System (INIS)

Concentrations of tritium in environmental waters (precipitation, rivers, lakes, tap water) have been determined using electrolytic enrichment and liquid scintillation counting. In waters of big rivers (the Vistula and the Odra rivers), lakes and tap water the annual average concentrations were similar to each other being from 1.4 to 1.9 Bq x dm"-"3. These concentrations were similar to those in the precipitation in which they ranged from 1.7 to 2.2 Bq x dm"-"3. The lowest tritium concentrations were found in waters of the Seashore Region rivers (average for 1994-1999 was 1.1 Bq x dm"-"3). The tritium concentrations in surface waters and in precipitation are still higher than that of natural level. The data obtained show that tritium concentration in the water of rivers might depend on the size of drainage area. The observed seasonal variations of tritium concentration in the precipitation collected in Warsaw and at the Mount Sniezka indicate ...

Energy Technology Data Exchange (ETDEWEB)

We utilize existing inclusive data on K{sup +}-meson momentum spectra of the reaction pp{yields}K{sup +}X at T{sub p}=2.3-2.85 GeV to deduce total cross-sections for pp{yields}K{sup +}{sigma}{sup +}n. The method used to extract those cross-sections is explained and discussed in detail. Our result for T{sub p}=2.85 GeV is consistent with the data point from a direct measurement at the same beam energy. The cross-section obtained for T{sub p}=2.3 GeV is with 13.7{+-}2.3 {mu}b considerably smaller than the value found in a recent experiment by the COSY-11 Collaboration at a somewhat lower beam energy, indicating that the pp{yields}K{sup +}{sigma}{sup +}n reaction cross-section could exhibit a rather unusual energy dependence. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The swelling and in-reactor creep behaviors of the PCA alloy have been determined from the irradiation of pressurized tube specimens in the FFTF reactor. These data have been obtained to a peak neutron fluence corresponding to approximately 80 dpa in the FFTF reactor for irradiation temperatures between 400 and 750/sup 0/C. Diametral measurements performed on the unstressed specimens indicate the possible onset of swelling in the PCA alloy for irradiation temperatures between 400 and 550/sup 0/C and at a neutron fluence corresponding to approx.50 dpa. The creep data suggest a non-linear fluence dependence and linear stress dependence (for hoop stresses less than 100 MPa) which is consistent with the in-reactor creep behavior of many cold worked austenitic stainless steels. These PCA creep data are compared to available 316 SS in-reactor creep data. The in-reactor creep strains for PCA are significantly less than observed in 20% cold worked 316 ...

Energy Technology Data Exchange (ETDEWEB)

There is an urgent need to monitor the condition of fluid-filled taped (FFT) cables. The Dissolved-Gas Analysis (DGA) technique that has been successfully applied to power transformers holds great potential for the preventive maintenance of FFT cables. However, before this emerging technique can be properly applied to cables, a suitable fluid sampling and subsequent gas analysis method had to be developed, including the generation of both laboratory and field data to aid in data interpretation. Data on gas saturation levels in various cable fluids have been presented. This paper describes a novel method developed specifically for FFT cables and discusses field results so obtained. The type, distribution and concentration of gases from fluid alone and paper alone under electrical stress has been presented, including the differences between normal and not-so-normal cable systems as demonstrated by DGA. The concept of wet tensile strength has been introduced to the ...

Energy Technology Data Exchange (ETDEWEB)

Bone-seeking radiopharmaceutical uptake (BSRU) was used to examine alveolar bone metabolism in a longitudinal study of tetracycline efficacy in beagle dogs. BSRU was measured in untreated control dogs and in beagles receiving either 250 mg or 500 mg oral tetracycline-HCl daily for 16 months. The rate of bone loss was determined for radiographs taken semiannually for a 6-month pretreatment period and for a 24-month treatment period. Measurements of BSRU obtained at month 16 of treatment were correlated with rates of bone loss determined radiographically in an attempt to determine whether BSRU was indicative of the subsequent rate of bone loss. A reduced rate of alveolar bone loss was found in the 500 mg tetracycline group at month 16 of the study relative to the untreated controls which was consistent with the decreased bone-seeking radiopharmaceutical uptake observed in this group. A significantly increased BSRU (p<.0001) was found in the ...

International Nuclear Information System (INIS)

Seeing convolved two-dimensional de Vaucouleurs profiles have been fitted to digital images of the brightest elliptical galaxies in two nearby groups of galaxies and three clusters of galaxies with redshifts in the range 0.06 to 0.15. The digital images were created by scanning electronographic plates obtained by the use of several versions of the RGO electronographic camera. The linear relation between effective surface brightness #mu#/sub e/ and the logarithm of the effective radius r/sub e/, first discovered by Kormendy to be valid for nearby elliptical galaxies, is found to be equally valid for the largest and brightest galaxies in rich clusters of galaxies. The apparent universal nature of that relation indicates that the same type of processes might have been involved during the formation of all ellipticals from cD galaxies in clusters to fainter ellipticals in small groups. It is suggested that the (I/sub e/,r/sub e/) relation is not ...

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The retention indices of cycloalkenes and cycloalkadienes with C/sub 6/-C/sub 13/ rings are determined by gas-liquid chromatography (GLC) on glass capillary columns coated with OV-1 and Ucon LB 550X and by gas-solid chromatrography (GSC) on a microcolumn packed with uncoated graphitized thermal carbon black (GTCB). Structure-retention correlations are derived on using index differences such as H/sup OV/, H/sup GTCB/ and ..delta..I values, considering the differences in the stereochemistry of these compounds. It is shown that the combined application of index increments obtained in GLC and GSC provides more detaled structure informations. The value of the retention index units agree with the most stable conformations of the alicyclic compounds. The high value for the energy equivalent to an index unit (..delta..G/sub I.U./ = 4.18 kJ/mol) confirms that graphitized thermal carbon black causes much stronger dispersive interactions than any nonpolar ...

Energy Technology Data Exchange (ETDEWEB)

Anorthosites are rocks consisting almost completely of calcic plagioclase, usually from andesine to labradorite. They are not widespread, and until recently were of no economic interest. However, with the advance of the new global tectonics, which has excited considerable interest in the structure and composition of upper-mantle rocks, interest in the anorthosites has grown. This has particularly been the case since the discovery of anorthosites on the moon, where they appear to be more widespread than on the earth. Data have recently been obtained on the strontium isotope compositions of anorthosite intrusions in the Dzhugdzhur-Stanovoy zone and in the rocks surrounding them, which have revealed some unexpected features. The paper describes the geological features of anorthosites, initial concepts on strontium isotope geochemistry, strontium isotope compositions of this region, and discusses some genetic consequences from the isotope data. Although the data of ...

Energy Technology Data Exchange (ETDEWEB)

A numerical investigation of a humidification dehumidification desalination (HDD) process using solar energy is presented. The HDD system consists mainly of a concentrating solar water heating collector, flat plate solar air heating collector, humidifying tower and dehumidifying exchanger. Two separate circulating loops constitute the HDD system, the first for heating the feed water and the second for heating air. A mathematical model is developed, simulating the HDD system, to study the influence of the different system configurations, weather and operating conditions on the system productivity. The model validity is examined by comparing the theoretical and experimental results of the same authors. It is found that the results of the developed mathematical model are in good agreement with the experimental results and other published works. The results show also that the productivity of the unit is strongly influenced by the air flow rate, cooling water flow rate and total solar ...

International Nuclear Information System (INIS)

The oscillation experiment of free-electron laser (FEL) was carried at the wave length 488 nm. The space and time properties and power of FEL were investigated. The typical macropulse structure indicated the time interval 20 ms and the pulse width 2 to 3 ms. About 1 ns was necessary to build up FEL. The space distribution of FEL showed beautiful TEM_0_0 mode, TEM_0_1 and TEM_0_2 mode. On the basis of data, 39 #mu#W average power was calculated at 2.9 mA accumulated current per bunch by integrating each response of pixel of CCD camera. The peak power was 1.2 W. In the oscillator, FEL power was average 1.2 W, peak 38 kW. On the electron beam, the stability of head tail was controlled by 6-pole-Quadrupole-6-pole (SQS) system made by an experimental basis. We succeeded the single set test, setting up single set in the ring. The characteristic properties of electron beam evaporation mirror of photo oscillator were studied and then new type photo oscillator to ...

Science.gov (United States)

A stochastic linear fractional programming (SLFP) approach is developed for supporting sustainable municipal solid waste management under uncertainty. The SLFP method can solve ratio optimization problems associated with random information, where chance-constrained programming is integrated into a linear fractional programming framework. It has advantages in: (1) comparing objectives of two aspects, (2) reflecting system efficiency, (3) dealing with uncertainty expressed as probability distributions, and (4) providing optimal-ratio solutions under different system-reliability conditions. The method is applied to a case study of waste flow allocation within a municipal solid waste (MSW) management system. The obtained solutions are useful for identifying sustainable MSW management schemes with maximized system efficiency under various constraint-violation risks. The results indicate that SLFP can support in-depth analysis of the ...

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Visual excitation is initiated by the absorption of a photon by the 11-cis retinal chromophore bound within the pigment called rhodopsin. We have used a variety of vibrational spectroscopies to obtain information about the vibrational nuclear dynamics that lead to this efficient photochemical isomerization. The cis-trans isomerization in rhodopsin is complete in only 200 fs. The extreme speed of this process, which is consistent with the {approximately}50 fs lifetime indicated by the spontaneous emission yield, suggests that the photochemistry involves non-stationary states or vibrational coherence. Recent studies have in fact observed vibrationally coherent oscillations of the ground state photoproduct called bathorhodopsin following impulsive excitation of the rhodopsin reactant. This conclusively demonstrates that the isomerization process in rhodopsin is vibrationally coherent. These observations further suggest that the isomerization ...

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This paper states the concept of a heat-resistant structure of the HOPE airframe having a 10 ton weight when lifting off and also the research situation of heat-resistant structural materials. To study the structure, established are design conditions for lift-off, reentry to the atmosphere and landing. As to the load condition, the load at the time of lift-off is most critical. Relating to the temperature environment condition, thermal analysis is made of the time when a HOPE is on the orbit (low-temperature range) and reenters the atmosphere (high-temperature range), when the temperature environment is critical. The analysis shows that the temrerature environment is in a {minus}80-1700{degree}C (range). The heat-resistant structural materials are developed so as to meet these conditions. The paper describes distribution of the airframe surface temperature by aerodynamic heating at the reentry, conceptual figures of the airframe structure and structural materials. Results of the study ...

Energy Technology Data Exchange (ETDEWEB)

We discuss recent results obtained for the heavy-fermion metals UPd{sub 2}Al{sub 3} and YbRh{sub 2}Si{sub 2}. UPd{sub 2}Al{sub 3} is the first among all superconductors for which tunneling and inelastic neutron-scattering data highlight a non-phononic, i.e., magnetic-exciton mediated, pair state. YbRh{sub 2}Si{sub 2} represents a model system exhibiting pronounced non-Fermi liquid effects above a weak antiferromagnetic phase transition at T{sub N}=70 mK. Upon approaching the quantum critical point (T{sub N}{yields}0), by low doping with Ge, one observes for T<0.3 K disparate behavior in the temperature dependences of both the electrical resistivity and the electronic specific heat as well as a Curie-Weiss law in the uniform magnetic susceptibility, implying uncompensated large 4f moments. These observations indicate a break up of the composite quasiparticles into their local f-spin and itinerant conduction-electron parts.

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We numerically constructed elementary phase-correct global quantum gates by using molecular electronic and vibrational states to encode two qubits and implement the Deutsch-Jozsa algorithm. The calculations were based on optimal control theory (OCT). The molecular species we chose were Na{sub 2} and Li{sub 2}. The electronic X{sup 1}{sigma}{sub g}{sup +} and A{sup 1}{sigma}{sub u}{sup +} states were taken as two orthonormalized energy levels of the electronic qubit. The vibrational qubits were those involved in these electronic states. The time duration of the optimized pulses with high fidelity was typically 500-900 fs, which reflects the wavepacket dynamics in electronically ground and excited states. When implementing the Deutsch-Jozsa algorithm by combining these elementary gates, we obtained a maximum probability 83.12% for Li{sub 2} molecule, which indicates that the electronic-vibrational qubits are worse than the vibrational-vibrational ...

International Nuclear Information System (INIS)

Water quality of the Citarum River and the Jatiluhur Reservoir in Indonesia was evaluated using C-14 radioisotope. A close relationship between the abiotic (physical and chemical) and the biotic (algal growth potential, primary productivity, chlorophylla and diversity index of planktonic and benthic macroinvertebrate) parameters was obtained. Algal growth potential to abiotic parameters relationship has the highest correlation coefficient and can be used as a pollution indicator. The other biotic parameters do not show clear relationship with the abiotic parameters. The Citarum water quality is the lowest in those locations which receive human and industrial waste from Bandung and its environment. This water cannot be used for drinking purposes and fishery. The water quality in other locations of the river, however, meets the criteria for agriculture. Agricultural waste does not show any drastic effect on the water quality profile due to ...

Science.gov (United States)

We prepared submicron-scale spherical hollow particles of anatase TiO2 by using a polystyrene-bead template. The obtained particles were very uniform in size, with a diameter of 490 nm and a shell thickness of 30 nm. The Brunauer-Emmett-Teller surface area measurements revealed a large value of 70 m2/g. The photocatalytic property was investigated by the complete decomposition of gaseous isopropyl alcohol under UV irradiation. It was indicated that the activity of the hollow spheres was 1.8 times higher than that of the conventional P25 TiO2 nanoparticles with a diameter of 30 nm. Furthermore, we fabricated a dye-sensitized solar cell (DSC) using an electrode of the TiO2 hollow spheres, and examined the photovoltaic performance under simulated sunlight. Although the per-area efficiency was rather low (1.26%) because of a low area density of TiO2 on the electrode, the per-weight efficiency was 2.5 times higher than those of the conventional DSCs ...

International Nuclear Information System (INIS)

The dependence of the photoluminescent properties of In_0_._4_8(Al_yGa_1_-_y)_0_._5_2P alloys (0#<=#y#<=#0.5) on growth temperature and substrate misorientation off GaAs(100) has been studied. Samples were grown using low-pressure metalorganic vapor phase epitaxy. By studying the dependence of ordering behavior in InGaP as a function of substrate misorientation and growth temperature simultaneously, a very large range in low-temperature photoluminescence emission energy---135 meV---has been obtained. The photoluminescence linewidth exhibits a strong, continuous dependence on the extent of atomic ordering (the emission energy) in the alloys. The results indicate that inhomogeneity in the microstructure of the material (i.e., between ''ordered'' domains and the ''disordered'' matrix) is the dominant photoluminescence broadening mechanism. This investigation has allowed a significant optimization of the optical properties of these materials, ...

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} The polarization curve of 316L SS possesses five turning potentials in passive region. {yields} Films formed at turning potentials perform different electrochemical and semiconductor properties. {yields} Dissolutions and regenerations of passive film at turning potentials are obtained by AAS and XPS. {yields} Turning potentials appearing in passive region are ascribed to the changes of the compositions of the passive films. - Abstract: The passivity of 316L stainless steel in borate buffer solution has been investigated by Mott-Schottky, atomic absorption spectrometry (AAS) and X-ray photoelectron spectroscopy (XPS). The results indicate that the polarization curve in the passive region possesses several turning potentials (0 V{sub SCE}, 0.2 V{sub SCE}, 0.4 V{sub SCE}, 0.6 V{sub SCE} and 0.85 V{sub SCE}). The passive films formed at turning potentials perform different electrochemical and semiconductor properties. ...

CERN Document Server

Site measurements were collected at Mount John University Observatory in 2005 and 2007 using a purpose-built scintillation detection and ranging system. $C_n^2(h)$ profiling indicates a weak layer located at 12 - 14 km above sea level and strong low altitude turbulence extending up to 5 km. During calm weather conditions, an additional layer was detected at 6 - 8 km above sea level. $V(h)$ profiling suggests that tropopause layer velocities are nominally 12 - 30 m/s, and near-ground velocities range between 2 -- 20 m/s, dependent on weather. Little seasonal variation was detected in either $C_n^2(h)$ and $V(h)$ profiles. The average coherence length, $r_0$, was found to be $7 \\pm 1$ cm for the full profile at a wavelength of 589 nm. The average isoplanatic angle, $\\theta_0$, was $1.0 \\pm 0.1$ arcsec. The mean turbulence altitude, $\\bar{h_0}$, was found to be $2.0\\pm0.7$ km above sea level. No average in the Greenwood frequency, $f_G$, could be established due ...

Energy Technology Data Exchange (ETDEWEB)

Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI{sub 3} or BBr{sub 3} discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates ({gt}6000thinsp{Angstrom}thinspmin{sup {minus}1}) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI{sub 3} or BBr{sub 3} content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO{sub 2} and SiN{sub x} of {ge}8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. {copyright} {ital 1998 American Vacuum Society.}

Energy Technology Data Exchange (ETDEWEB)

Microwaves were used to induce self-propagating high temperature synthesis (SHS) in the reaction 3TiO{sub 2}+3C+(4+x)Al {yields} 3TiC+2Al{sub 2}O{sub 3}+xAl. The SHS process was studied for x = 0 and 4, using slow and fast heating rates and with and without the application of uniaxial pressure. Less than 50 watts was required to internally ignite the samples using a TE{sub 102} microwave cavity mode. Uniaxial stresses in the range of 200-1400 psi were continuously applied along the vertical axis of some of the processed samples as the SHS reactions were initiated. SEM photomicrographs clearly indicate differences in the formation of whiskers and other microstructural features in the products obtained from microwave and conventional hot wire techniques. The x = 0 samples processed with fast and slow microwave heating rates reached higher densities than the conventionally processed samples.

Energy Technology Data Exchange (ETDEWEB)

We investigated a method of analyzing the hemodynamics of the lung mass by contrast enhanced dynamic computed tomography (dynamic CT) to determine the difference in vascular supply between the pulmonary artery and bronchial artery using an experimental model. Our experimental model consisted of two injectors connected to two tubes, representing the pulmonary artery and bronchial artery, which were further connected to a chamber representing the lung mass. Following infusion of contrast medium into each tube with some delay time, dynamic CT scans were performed to obtain time density curves of the two tubes and the chamber. Using the time-density curve of contrast passage, flow rates from the two tubes into the chamber were calculated by the curve fitting method. Calculated values correlated well with the adopted flow rates of fluid from the injectors (r=0.893) in the experiment. The results indicate our method of individually measuring flow ...

Energy Technology Data Exchange (ETDEWEB)

In the case of total skin electron therapy without the beam guide, the electron beam is scattered just outside the gantry exit, dose uniformity in the field is broken, and dose is spread outside the light field. The aims of this study were to measure the mean energy of the off-axis incident electron beam without the beam guide and to establish a reference for the clinical situation. For the measurement, a 4 MeV electron beam was selected among several energies from the linear accelerator. A scintillating fiber beam energy monitor measured the mean energy of the incident electron beam. This energy monitor is a small, light-weight piece of equipment composed of a wedge absorber, scintillation fiber, and photodiode. We found the relationship between electron energy and the indicated value of the energy monitor by means of the estimation of correction factors for five different kinds of electron energy. The preferable linear correlation of 0.997 of the coefficient of ...

Science.gov (United States)

Computer programs have been developed to define the temperature increase which would be needed to bring deep-ocean water into density equilibrium with surface water for locations where data are available. A series of continuous-flow studies on phytoplankton blooms resulting from mixtures of 80 percent deep and 20 percent surface water in 2000-liter concrete culturing vessels (''reactors'') has been completed. A quantitative determination of nutrient utilization and flow through a combined primary and secondary trophic level system has been completed. This study utilized the clam Tapes semidecussata, fed from phytoplankton grown in 80 percent deep and 20 percent surface water. An analysis of the fate of the deep water discharged from a floating OTEC plant indicates that horizontal containment of the resulting deep water: surface water mixture is necessary if conditions optimal for open-sea mariculture are to ...

Energy Technology Data Exchange (ETDEWEB)

Antitumor platinum(II) complexes derived from N-alkyl-propanediamine differing in the length of their carbon chain (C8, C10, C12 and C14) were incorporated in liposomes and the cytotoxic activity of these formulations was evaluated against tumor (A{sub 549}, MDA-MB-231, B16-F1 and B16-F10) and non-tumor (BHK-21 and CHO) cell lines. Stable and monodisperse liposome suspensions incorporating the platinum complexes were obtained from the lipid composition consisting of distearoyl-sn-glycero-3-phosphocholine, cholesterol and 1,2-distearoyl-sn-glycero- 3-phosphoethanolamine-N-(methoxy(polyethylene glycol)-2000) at 5:3:0.3 molar ratio. The entrapment efficiency (EE%) of the platinum complexes in liposomes increased with the carbon chain length. EE% was higher than 80% in C12- and C14-derivatives. The effect of liposome encapsulation on the cytotoxic activity of the complexes was found to depend on the carbon chain length. These data indicate that the ...