Samples of vitamin D fortified orange juice obtained from retail food stores were analyzed for vitamin D3 content using a method developed by combining the best features of two AOAC methods. Detection by ultraviolet absorption at 265nm was compared to detection by selected ion monitoring (SIM) using atmospheric pressure chemical ionization (APCI) mass spectrometry (MS). Furthermore, an ion trap (IT) mass spectrometer was employed in a 'dual parallel MS' arrangement to simultaneously obtain qualitative APCI-ITMS data. The method was applied to 33 samples of 3 national American orange juice brands and 7 samples of 5 other American brands collected using a statistically designed sampling plan as part of the National Food and Nutrient Analysis Program to provide values for the USDA National Nu...
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, with features including a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), trace chemicalanalysis of each distillate fraction, and a corrosivity assessment of each distillate fraction. In the present contribution, we present the application of the advanced distillation curve method to a bio-derived crude oil prepared from swine manure. One motivation behind the work was to precisely measure the distillation curve of the oil derived from swine manure with our advanced distillation apparatus and compare the bio-derived oil to traditional pe...
The increasing number of hazardous materials accidents in the United States has resulted in new federal regulations addressing the emergency response activities associated with chemical releases. A significant part of these new federal standards (29 CFR 1910.120 and 40 CFR Part 311) requires compliance with specific criteria by all personnel involved in a hazardous material emergency. This study investigated alternative lesson design models applicable to instruction for hazardous material emergencies. A specialized design checklist was created based on the work of Gagne, Briggs, and Wager (1988), Merrill (1987), and Clark (1989). This checklist was used in the development of lesson plan templates for the hazardous materials incident commander course. Qualitative data for establishing learning objectives was collected by conducting a needs assessment and a job analysis of the incident commander position. Incident commanders ...
Probabilities of flucton production have been calculated for the 1p-shell nuclei and its modification by the Yastrov method. The results obtained are in a qualitative agreement with the data resulting from the analysis of experiment in an assumption of a flucton mechanism of proton-nuclear inclusive reactions with the production of cumulative particles.
BackgroundAlthough the health benefits of breastfeeding are well established, early introduction of formula remains a common practice. Cultural beliefs and practices can have an...Full Text Available
Values of the chemical yield, G, and of the molar extinction coefficient, epsilon, for Fricke dosimetry, have been recommended by ICRU. For epsilon, the value in ICRU Reports 17 and 21, 2205 1.mol"-"1.cm"-"1, based on an analysis of 83 reported values. It was suggested that, where neither a careful wavelength calibration nor absorbance linearity checks had been performed, a standard error of 1.5% should be assumed; otherwise 0.15% could be accepted. Alternatively, the accuracy in applying this chemical dose meter was considered improved if there was an independent determination of epsilon with the same spectrophotometer as was used for the determination of the optical density of irradiated Fricke solution. The accuracy claimed for both methods remains questionable, since no complete argumentation could be given for the differences of up to 13% in the published values. Taking into account the discussion of the sources of ...
The radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for rapid and nondestructive analysis of metallic glasses. The methods were compared for accuracy and precision with the atomic absorption method. Some results of the analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width as well as the length and a qualitativeanalysis of the composition of material surfaces are considered. (author).
Radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for a rapid and nondestructive analysis of metallic glasses. The methods are compared in accuracy and precision with the atomic absorption method. Some results of analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width and length, and a qualitativeanalysis of the composition of material surfaces are considered. (author) 3 refs.
Nitriding leads to improved tribological and corrosive properties of iron alloy components. In order to study the effect of plasma nitriding parameters on the structure of compound layer and diffusion zone, a systematic variation of process parameters, temperature and process gas atmosphere has been carried out. Metallographic inspection, X-ray diffraction and glow discharge optical spectroscopy analysis (GDOES) were used in this investigation. The results clarified that depending on the amount of nitrogen in the gas atmosphere nitrided layers with and without compound layer can be generated in the surface of M2 tool steel for temperatures from 350 C to 500 C. For plasma nitriding in 5 vol.% Nitrogen and 95 vol.% Hydrogen no compact compound layer was formed. The gas mixture of 76 vol.% Nitrogen resulted in compound layer formation for all temperatures from 350 C to 500 C. X-ray phase analysis indicated an almost 100% {epsilon}-(carbo)nitride ...
Dimethyl methylphosphonate (DMMP), a chemical simulant of the nerve gas GB, was decontaminated with a nonthermal atmospheric pressure plasma. The decontamination efficiency was measured qualitatively by means of Fourier transform spectroscopy and quantitatively by means of gas chromatography. With helium gas only, 10g/m2 of DMMP on an aluminum surface was 99.9% decontaminated in 2min, furthermore, with the addition of 5% of oxygen gas, it was 99.99% decontaminated in 10min. Given the low input power (<100W) and temperature (<75degreeC), this plasma is eligible for nondestructive decontamination of almost all material surfaces.
This work gives a global view of legislations in which are included metals chemical states, briefly recalls the conditions to be respected for the CRM (Certified Reference Materials), and describes the results of some current plans for the Norms, Measures and Tests program. (O.M.) 23 refs.
The existence of thresholds for toxicants is a matter of debate in chemical risk assessment and regulation. Current risk assessment methods are based on the assumption that, in the absence of sufficient...Full Text Available
The principle is described of X-ray fluorescence analysis and the manner of detecting the emitted characteristic radiation. The advantages are presented of radionuclide X-ray fluorescence analysis which consist primarily in the possibility of conducting a totally non-destructive analysis, and of accurate and relatively narrow localization of the analyzed area, the simultaneous qualitative and quantitative determinations of a large number of elements in the order of concentrations 10"1 to 10"-"4%, stability of excitation radiation flux, simple design and relatively low capital costs. The so-called matrix effect is pointed to. A number of examples is given of the use of the cited method, including its use in the analysis of art objects. (J.B.).
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. This new method is a significant improvement over current approaches, with features including a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), trace chemicalanalysis of each distillate fraction, and a corrosivity assessment of each distillate fraction. In the present contribution, we present the application of the advanced distillation curve method to a bio-derived crude oil prepared from swine manure. One motivation behind the work was to precisely measure the distillation curve of the oil derived from swine manure with our advanced distillation apparatus and compare the bio-derived oil to traditional petroleum crude oils. Then, the information content of the bio-derived oil distillation was extended further with the ...
Geostatistical techniques make it possible to qualitatively and quantitatively analyze spatiotemporal inherent characteristics of environmental radiation or radioactivity. Spatial patterns and trend analysis of environmental radioactivity, e.g., {sup 137}Cs and {sup 40}K, in soil around nuclear facilities (Kori, Wolsung, Yeonggwang, Uljin, and Daejeon) will be investigated and discussed.
The qualitative technique of the analysis of the efficiency of the RF plasma production is presented in which the solution of boundary problem for Maxwell's equations is only necessary. The analysis of the character of the plasma production process with the crankshaft antenna in Uragan-2M stellarator is carried out. The discussion of the calculations results is presented.
The applicability of the radionuclide X-ray fluorescence analysis (RXFA) for qualitative and quantitative evaluation of environmental plant samples is discussed and examples of determination of Mn, Fe, Ni, Cu, Zn, Pb in samples of apple trees are given. The instrumentation, the standard and sample preparation are also presented.
Experiments in a homogeneous charge compression ignition (HCCI) engine have been conducted with four gasoline surrogate fuel blends. The pure components in the surrogate fuels consisted of n-heptane, isooctane, toluene, ethanol and diisobutylene and fuel sensitivities (RON-MON) in the fuel blends ranged from two to nine. The operating conditions for the engine were p{sub in}=0.1 and 0.2 MPa, T{sub in}=80 and 250 C, {phi}=0.25 in air and engine speed 1200 rpm. A semidetailed chemical kinetic model (142 species and 672 reactions) for gasoline surrogate fuels, validated against ignition data from experiments conducted in shock tubes for gasoline surrogate fuel blends at 1.0{<=} p{<=}5.0MPa, 700{<=} T{<=}1200 K and {phi}=1.0, was successfully used to qualitatively predict the HCCI experiments using a single zone modeling approach. The fuel blends that had higher fuel sensitivity were more resistant to autoignition for ...
A graphic approach, terms a Genetic Activity Profile (GAP), was developed to display a matrix of data on the genetic and related effects of selected chemical agents. The profiles provide a visual overview of the quantitative (doses) and qualitative (test results) data for each chemical. Either the lowest effective dose or highest ineffective dose is recorded for each agent and bioassay. Up to 200 different test systems are represented across the GAP. Bioassay systems are organized according to the phylogeny of the test organisms and the end points of genetic activity. The methodology for producing and evaluating genetic activity profile was developed in collaboration with the International Agency for Research on Cancer (IARC). Data on individual chemicals were compiles by IARC and by the US Environmental Protection Agency (EPA). Data are available on 343 compounds selected from volumes 1-53 of the IARC ...
Three blocks of non-welded tuff, one nominally one cubic foot (trial block) in volume and the other two, nominally one cubic meter (1 m3) in volume, were excavated from the Busted Butte Test Facility on the Nevada Test Site in 1999 and transported to the Atomic Energy of Canada Limited Whiteshell Laboratories in Pinawa, Manitoba. The trial block and one of the 1-m3 blocks were used for radionuclide migration experiments under unsaturated conditions; the remaining 1-m3 block was used for similar migration experiments under saturated conditions. After a vertical flow of synthetic transport solution was set up under unsaturated conditions, a suite of conservative and chemically reactive radionuclide tracers was injected at volumetric flow rates of 20 mL/hr in the trial block, and 10 mL/hr in two locations on the upper surface of the 1-m3 block. These flow rates correspond to infiltration rates of about 120 cm/year and about 17 cm/year, respectively. The duration of ...
Impact of some heavy metals like zinc, lead, copper, chromium and cadmium were studied at four spots on the macro-invertebrate fauna of the Thaddo stream, a tributary of Malir River. This was in correlation with an earlier study on the physico-chemical aspects of water which showed a severe pollution in this stream. Present data for the qualitative and quantitative analyses of macro-invertebrates and the ranges of heavy metals (Zn 0.5-3.5, Pb 0.90-1.42, Cu 0.35-0.93, Cr 0.0-0.08 and Cd 0.003-0.01 ppm) in the water samples also indicate high level of pollution in the stream. Macro-invertebrate fauna comprises only of aquatic insects which include larvae of Chironomus spp., adults of the Notonectus sp., and nymphs of Gomphus sp. (dragon fly) belonging to the order Diptera , Hemiptera and Odonata, respectively. Quantitatively Notonectus sp. predominated and followed by Chironomus larvae. The maximum concentrations of all heavy metals were recorded ...
Three blocks of non-welded tuff, one nominally one cubic foot (trial block) and the other two, nominally one cubic metre (1 m{sup 3}), were excavated from the Busted Butte Test Facility on the Nevada Test Site and transported to the Atomic Energy of Canada Limited Whiteshell Laboratories in Pinawa, Manitoba. The trial block and one of the 1-m{sup 3} blocks were used for unsaturated flow experiments. The remaining 1-m{sup 3} block is being used for saturated flow experiments and will be reported on separately. After a vertical flow of synthetic transport solution was set up under unsaturated conditions, a suite of conservative and chemically reactive radionuclide tracers was injected at volumetric flow rates of 20 mL/hr in the trial block, and 10 mL/hr in the 1-m{sup 3} block. The duration of the migration experiment in the trial block was 87 days, while the migration experiment in the 1-m{sup 3} block was continuing after 600 days. Results obtained from the ...
The measurement of air pollutants is no more sufficient. It is necessary to assess the risk induced by air pollution, and then to put in place actions to reduce it. The air quality monitoring takes into account different pollutants: nitrogen oxides, carbon monoxide, particulates for the traffic; sulfur dioxide and particulates for use of fuel or coal or chemical transformations in air; ozone and nitrogen dioxide from hydrocarbon and nitrogen oxides emissions; the use of simulation methods allow to calculate the concentrations levels for these pollutants taken as indicators. (N.C.)
This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025,...Full Text Available
Abstract Rationale, aims and objectives- Finding ways to incorporate disparate types of evidence into research syntheses has the potential to build a better evidence base for clinical practice and policy. Yet conducting such mixed research synthesis studies is challenging. Researchers have to determine whether and how to use adjusted and unadjusted quantitative findings in combination with each other and with qualitative findings. Methods- Among quantitative findings, adjustment for confounding, either via study design or statistical analysis, can be a considerable source of heterogeneity. Yet there is no consensus about the best way to synthesize findings resulting from different methods for addressing confounding. When synthesizing qualitative and quantitative findings, additional consid...
Adventure based counselling is a short-term experiential psychotherapeutic approach, which utilises adventurous activities and being in natural environmental in order to facilitate therapeutic change in clients. The present paper critically appraises the results of a qualitative study that investigated how clients with self-reported anxiety and depression experienced participating in an innovative counselling intervention with combined individual counselling with such an adventurous outdoor transaction. Interpretative Phenomenological Analysis, as described by Smith and Osborn (2008), was used in order record and analyse the experiences of four male and six female students who were treated at the Teesside's University Counselling Service. Interviewees perceived the counselling sessions as ...
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of...
Modern radiometric analytics demands a complex consideration of nuclear and electron shell processes, if more pretentious aims are envisaged. As an example the small variation of decay rates of radionuclides presents possibilities for information on chemical situations of decaying atoms. In principle this phenomenon is well known since many years, but now the situation is such that, e.g. in /sup 99m/Tc internal conversion, a full agreement of the difficult experiments and the respective theory was established. The secondary emission of X-rays as a consequence of high excitation of electron shells in combination with nuclear transitions supplies another example for a methodical progress of radiometry. Investigations on "5"1Cr as an electron capture nuclide have shown that chemically induced variations of the K/sub #alpha#/ to K/sub #beta#/ X-ray intensity ratio is at least qualitatively understood. (author).
The present investigation is a case study of Lucknow, the main metropolis in Northern India, which succumbs to a major problem of municipal solid waste and its management. A qualitative investigation using strengths, weaknesses, opportunities and threats analysis (SWOT) has been successfully implemented through this community participation study. This qualitative investigation emphasizes the limited capabilities of the municipal corporation's resources to provide proper facilitation of the municipal solid waste management (MSWM) services without community participation in Lucknow city. The SWOT analysis was performed to formulate strategic action plans for MSWM in order to mobilize and utilize the community resources on the one hand and municipal corporation's resources on the other. It has allowed the introduction of a participatory approach for better collaboration between the community and municipal ...
Results are presented from an evaluation of the effect of the quality of the iron-ore-bearing raw materials and coke on the performance of blast furnaces at the Novolipetsk Metallurgical Combine. It is shown that the technical-economic indices of the smelting operation are improved by increasing the pellet content of the charge, the basicity of the sinter, and the sinter?s content of the ?5 mm fraction. An analysis of the performance of the blast furnaces on coke with a hot-strength index CSR = 40?60% confirmed the qualitative and quantitative effect of this index on furnace productivity and coke consumption. The analysis also showed that the magnitude of this effect depends on smelting rate and the basicity of the furnace slag.
The report gives results of an examination, including mutagenic screening, of the chemical composition of residual fuel oils and their column chromatography pre-fractions. A degree of correlation between composition and mutagenicity has been achieved. Radionuclide data has been o...
Several works about annual meeting of the Brazilian Chemical Society are present.The search for medicinal chemistry, natural products, biological chemistry, and organic chemistry are shown. Conventional methods and some techniques are discussed and developments of new methods of determining are studied. The use of new chemical compounds, materials, structures and chemicalanalysis are shown.
An analysis system for the long-term mechanical behavior of barrier materials (MACBECE: Mechanical Analysis system considering Chemical transitions of BEntonite-based and CEment-based materials) was developed in order to improve the reliability of the evaluation of the hydraulic field which is one of the important environmental conditions in the safety assessment of the TRU waste disposal. MACBECE is the system that calculates the deformation of barrier materials using their chemical property changes as inputs, and subsequently calculates their hydraulic conductivity taking both their chemical property changes and deformation into consideration. By using MACBECE, the long-term deformation and the transition of hydraulic field for the round-type disposal cavities were evaluated, assuming some sets of chemical evolution data as input. Based on the ...
The thermal analysis of a turbine stack discharging exhaust gases to the atmosphere is presented. The examined turbine stack belongs to a gas lift plant for oil extraction located in the Gulf area. The analysis has been performed because an overheating of the anchor flange/bolts and of the concrete foundation occurred and caused small cracks in the upper layer of the foundation. A qualitative thermal analysis of the stack has pointed out that the main cause of the overheating was the thermal radiation in the air-filled region underneath the stack bottom plate. Detailed calculations performed by using a CFD code (Fluent ver. 6.0.12), cross-checked with measurements taken from site, have shown that a significant reduction of the heat flux to the foundation could be obtained by filling the above mentioned air region with an insulating material. The benefits of this solution are prevailing over those ...
Heat transfer processes use fluids which are generally not pure and can react with transfer surfaces. These surfaces are subject to deposits which can be sediments harmful to heat transfer and to integrity of materials. For nuclear plant steam generators, sludge build-up accelerates secondary side corrosion by concentrating chemical species. A major safety problem involved with such a corrosion is the growing of circumferential cracks which are very difficult to detect and size with eddy current probes. With a view to understand and control this problem, it is necessary to develop a mathematical model for the prediction of sludge behavior in PWR steam generators. Based on fundamental principles, this work intends to use different models available in literature for the prediction of the phenomenon leading to the accumulation of sludge particles at the bottom (the tubesheet) of a PWR. For that, a three-dimensional simulation of magnetite particulate fouling with the ...
The values of X = 0.77, Z = 0.035, and Y = 0.195 and the stage of evolution of Procyon are determined from the evolutionary tracks and the results of an analysis of the chemical composition of the atmosphere.
We report a detailed augmented-plane-wave energy-band study and wave-function analysis of stoichiometric PdH which shows that, even though the Fermi surface of PdH is qualitatively similar to that of silver, the simple ''proton model'' is not valid. Instead, the screening of the proton in PdH is found to be larger than in an isolated H atom due, in part, to the formation of a H-Pd bonding band below the bottom of the d-band complex. This result, which is in qualitative agreement with Switendick's earlier calculation, is confirmed by ultraviolet photoemission experiments. A partial density-of-states (DOS) analysis in the energy range spanned by the six valence and conduction bands reveals the quantitative details of the bonding mechanism between the Pd and H constituents. At the Fermi energy, the high Pd d to H s DOS ratio approx. 10.3 is found to be far higher than expected in silver, despite the fact ...
In Japan, cosmetics claiming hormesis effect are available through Internet. Although these cosmetics show the contents, they never mention the minor elements and radioactive sources. The existence of radioisotopes, however, was observed by measurements of the gamma-rays with a HPGe detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics including radioactive sources were analyzed using INAA, PGAA and NAA with multiple gamma-ray detection (NAAMG). Nineteen elements were analyzed quantitatively in hormesis cosmetics by INAA, PGAA and NAAMG and 16 elements were detected qualitatively by SEM-EPMA. (author)
CIRNAT, a one-dimensional code for natural circulation analysis, was described. The homogeneous approach was adopted for the two-phase flow regime and different heat transfer regimes were considered. The code was exhaustively tested for one-phase flow systems. For two phase flows a boiling/condensing system was simulated. The results are qualitatively correct but the oscillations observed at the system were not captured by the model. Other two-phase flow tests must be done to show the limits of the homogeneous approach before the introduction of a more complex model. (author)
CIRNAT, a one-dimensional code for natural circulation analysis, was described. The homogeneous approach was adopted for the two-phase flow regime and different heat transfer regimes were considered. The code was exhaustively tested for one-phase flow systems. For two phase flows a boiling/condensing system was simulated. The results are qualitatively correct but the oscillations observed at the system were not captured by the model. Other two-phase flow tests must be done to show the limits of the homogeneous approach before the introduction of a more complex model. (author)
This work describes a procedure for the adaptive time dependent Finite Element Method using an automatic mesh refinement (H-Version) that efficiently reduces estimated errors ( a posteriori) below pre-assigned limits. Classical model problem for steady-state heat transfer are investigated, and the results are compared with the analytical solution. Then some typical time-dependent problem are qualitatively analysed. (author) 10 refs., 7 figs.
Petrographical analysis is a microscopical analytical tool which allows definition of the exact nature of the components of different concrete mixes, as well as definition of internal structures and alteration processes. In order to improve the precision and the swiftness of the petrographical analysis, an automated image analysis system has been developed. In the next stage of this study, which consisted in the testing of new concrete mixes containing fluidised bed ashes, petrography has been used, not only to identify the nature of the mix components, but also assess the behaviour of these new concrete mixes when exposed to aggressive conditions.
The following aspects will be discussed: The main function of the Division of Inspection Services and its role in the Marketing of agricultural products; the shelf life of agricultural products: short review of present methods with a practical example of losses incurred due to limited keeping quality; irradiation and heat treatment: advantages of inhibited microbiological activities and undesirable chemical changes from a quality control point of view; quality standards: the basic principles of quality control; consequences of effective post-harvest treatment: export of deciduous and citrus fruit; the magnitude of the problem of poor keeping quality and quality requirements; other fruit; quantities and export limitations and vegetables; quantity and quality requirements; local marketing: fruit and vegetables subjected to inspection; quantity and quality aspects.
The term Process Systems Engineering (PSE) is relatively recent. It was coined about 50 years ago at the outset of the modern era of computer-aided engineering. However, the engineering of processing systems is almost as old as the beginning of the chemical industry, around the first half of the 19th century. Initially, the practice of PSE was qualitative and informal, but as time went on it was formalized in progressively increasing degrees. Today, it is solidly founded on engineering sciences and an array of systems-theoretical methodologies and computer-aided tools. This paper is not a review of the theoretical and methodological contributions by various researchers in the area of PSE. Its primary objective is to provide an overview of the history of PSE, i.e. its origin and evolution; ...
A variety of observations suggest that the Universe had a hot dense origin and that the pregalactic composition of the Universe was determined by nuclear reactions that occurred in the first few minutes. There is no unique hot Big Bang theory, but the simplest version produces a primeval chemical composition that is in good qualitative agreement with the abundances deduced from observation. Whether or not any Big Bang theory will provide quantitative agreement with observations depends on a variety of factors in elementary particle physics (number and masses of stable or long-lived particles, half-life of neutron, structure of grand unified theories) and from observational astronomy (present mean baryon density of the Universe, the Hubble constant and deceleration parameter). The influence of these factors on the abundances is discussed, as is the effect of departures from homogeneity and isotropy in the early Universe.
A detailed chemical kinetic model to describe the autoignition of gasoline surrogate fuels is presented consisting of the fuels iso-octane, n-heptane, toluene, diisobutylene and ethanol. Model predictions have been compared with shock tube ignition delay time data for surrogates of gasoline over practical ranges of temperature and pressure, and the model has been found to be sensitive to both changes in temperature and pressure. Moreover, the model can qualitatively predict the observed synergistic and antagonistic non-linear blending behaviour in motor octane number (MON) for different combinations of primary reference fuels (PRFs) and non-PRFs by correlating calculated autoignition delay times from peak pressures and temperatures in the MON test to experimental MON values. The reasons for the blending behaviour are interpreted in terms autoignition chemistry. 37 refs., 11 figs., 4 tabs.
Certain applications are described of radionuclide X-ray fluorescence analysis in the ore dressing industry, in the manufacture of building materials, in metallurgy, pharmacy, in the chemical, photographic and paper industries, in space exploration, in archeology and for measuring the thicknesses of thin layers of coatings. (ES).
This thesis deals with the evaluation of Solar Grade Silicon (SoG-Si) purified by different techniques, and also the fabrication and characterization of high efficiency and advanced bifacial solar cells. In the beginning of Chapter 1, various SoG-Si production methods relevant for this work are qualitatively described. The three feedstock materials used in this work are from the Fluidized Bed Reactor (FBR) process, metallurgical feedstock-I and feedstock-II process. In metallurgical feedstock-I, the lifetime of the minority charge carriers in multicrystalline silicon (mc-Si) samples at the grain boundaries are found to be higher than the grains themselves possibly due to lower resistivities in the grain boundaries. The efficiency of the best solar cell obtained using the mc-Si metallurgical feedstock-I is 16.1%. It has been identified that the fast light induced degradation, whose magnitude is lower than that of a reference cell suggests the formation of a B-metal ...
To form a licensing basis for a new methodology for a fuel channel safety analysis code for CANDU-6 nuclear reactor, a CATHENA model for a post-blowdown fuel channel analysis has been developed, and tested for a high temperature thermal-chemical experiment CS28-1 [Lei, Q.M., 1993. Post-test analysis of the 28-element high-temperature thermal-chemical experiment CS28-1. In: 4th International Conference on Simulation Methods in Nuclear Engineering, Montreal, PQ, 1993]. Pursuant to the objective of this investigation, the current study has focused on understanding the involved phenomena, their interrelations, and how to maintain a good accuracy of the temperature and H2 generation rate prediction without losing the important physics of the involved phenomena. The transient simulation results ...
Classical methods for the study of complex fluid phase behavior include static and dynamic equilibrium cells that usually require vapor and liquid recirculation. These are sophisticated, costly apparatus that require highly trained operators, usually months of labor-intensive work per mixture, and the data analysis is also rather complex. Simpler approaches to the fundamental study of azeotropes are highly desirable, even if they provide only selected cuts through the phase diagram. Recently, we introduced an advanced distillation curve measurement method featuring: (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation o...
Abstract: The recent National Academy of Sciences report on forensic sciences states that the study of fire patterns and debris in arson fires is in need of additional work and eventual standardization. We discuss a recently introduced method that can provide predicted evaporation patterns for ignitable liquids as a function of temperature. The method is a complex fluid analysis protocol, the advanced distillation curve approach, featuring a composition explicit data channel for each distillate fraction (for qualitative, quantitative, and trace analysis), low uncertainty temperature measurements that are thermodynamic state points that can be modeled with an equation of state, consistency with a century of historical data, and an assessment of the energy content of each distillate fraction...
A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...
Reducing count losses and pile-up pulse effects in quantitative and qualitativeanalysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.
The activity of tyrosine aminotransferase (TAT) in the liver of mice subjected simultaneously to ionizing radiation and to local inflammatory process showed in the first 24 hours of the experiment statistically significant changes resulting from summation of the harmful effects of both factors. In the second 24-hour period an evident tendency was observed for return of a normal circadian rhythm of the enzyme. This points to presence of an endogenous mechanism of suppression of the manifestations of significant desynchronization of the circadian rhythm. The paper contains also a trial of mathematical analysis of changes in TAT activity in the circadian rhythm, a description and analysis or the suppression process, qualitative and quantitative determination of the phenomenon of cumulation of the effects of powerful stress factors acting on the animal organism. The obtained results were compared with the results of ...
We investigate the asymptotic properties of the Bianchi type IX cosmological model in the brane-world scenario. The matter content is assumed to be a combination of a perfect fluid and a minimimally coupled scalar field that is restricted to the brane. A detailed qualitativeanalysis of the Bianchi type IX brane-world containing a scalar field having an exponential potential is undertaken. It is found that the brane-Robertson-Walker solution is a local source for the expanding Bianchi type IX models, and if k"2<2 the ever-expanding Bianchi IX models asymptote to the power-law inflationary solution. The only other local sink is the contracting brane-Robertson Walker solution. An analysis of the Bianchi type IX models with a scalar field with a general potential is discussed, and it is shown that in the case of expanding models, for physical scalar field potentials close to the initial singularity, the scalar field is ...
Secondary ion mass spectrometry (SIMS), secondary electron microscopy (SEM) and X-ray analysis have been applied to the measurement of U-bearing particles with the intent of gleaning information concerning their history and/or origin. The lead isotopic abundances are definitive indicators that U-bearing particles have come from an ore-body, even if they have undergone chemical processing. SEM images and X-ray analysis can add further information to the study that may allude to the extent of chemical processing. The presence of 'common' lead that does not exhibit a radiogenic signature is clear evidence of anthropogenic origin. (author)
The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K{beta} characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO{sub 2}, and the SiO{sub 2} contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).
The purpose of the present study is to develop a new method for chemical state analysis by means of EPMA(Electron probe microanalyser). The measured X-ray intensity of Si-K#beta# characteristic X-ray spectra were read-out by a 16 bit microcomputer with a RS-232C interface. And using the curve fitting method the quantitative analysis of chemical compositions in a ternary compound that constituted of the same element has been established. The present method was applied to analyse of the friction and wear properties of Si-base ceramics sliding materials. It was found that the wear debris contains both the compositions of the sliding materials and SiO_2, and the SiO_2 contents in wear debris was changed with relative humidity. The results clearly showed that the proposed method is very useful for determing the compositions in the ternary compound. (author).
Photoelectron resonance capture ionization (PERCI) mass spectrometry has been developed for the direct online analysis of organics, including lipids. Analysis is conducted without the need for sample preparation or chemical derivatization such as methylation, foregoing the use of harmful or toxic chemicals. PERCI is currently being adapted towards the analysis of edible oils. Herein, as a proof of principle of the simplicity and potential utility of this method towards the analysis of edible oils, we present the analysis of the prevalent fatty acids (FA) in Tuscan extra-virgin olive oil along with triolein and linolenic acid (LNA) standards. Ionization of olive oil results in little fragmentation of the prevalent FA, which are measured as their molecular ions, [FA-H]-. The relative concent...
The feasibility was studied of the application of radionuclide X-ray fluorescence analysis to the identification and determination of chemical elements in the air. A description of the method is presented, the main stages of the analysis are discussed (sample preparation and standards, selection of radioactive radiation sources, geometry of measurement and evaluation of results). The method is illustrated on the determination of elements Fe, Cu, Zn, Br, and Pb in air samples taken in the city of Prague. (author) 2 tabs., 2 figs., 14 refs.
Boiling phenomenon is responsible for impurities concentration in the liquid phase and then can involve chemically aggressive conditions. This paper presents the methodology developed by NOVATOME to know the water quality conditions in the boiling zone and under deposits, in order to improve corrosion tests and materials reliability and safety. Calculations show that concentration of chloride and sodium hydroxide for example can reach significant levels which may lead to corrosion risks. (author).
The biological activity of coir fibre, coir ash and their components were investigated in vitro by measuring the haemolytic activity and macrophage cytotoxicity. In vivo studies carried out by injecting guinea pigs intratracheally with coir fibres resulted in resolving granulomas. The observed haemolytic activity and macrophage cytotoxicity was more marked with coir ash compared with coir fibres. Chemicalanalysis of coir ash revealed the presence of toxic chemical constituents in appreciable amounts. PMID:6283694
Contents include: introduction; river systems; physical processes; chemical processes; estuaries and coastal zone; introduction; physical processes; chemical processes; the role of sediments; introduction; the anoxic layer; major-element chemistry; minor-element chemistry; the oxic-anoxic interface; assessment; introduction; analysis of sediments; modelling.
This paper reports the findings of a study that explores the perspectives of 25 young Cypriots regarding the symbolic values of smoking with respect to their everyday lived experiences. This study was motivated by recognising the high levels of smoking prevalence among adolescents in Cyprus and the absence of published research 'recording' their own versions of reality about smoking. Data for the study were generated from one-to-one qualitative interviews which encouraged the participants to articulate the symbolic value of smoking in their day-to-day experiences. The analysis focuses first, on the content of the embedded symbolic values of smoking (e.g. the quality of being 'cool') and second on the role of these values (e.g. used in projecting an image) in their everyday lives. A central...
Momentum transfer through an air-water interface was studied in a horizontal rectangular channel through experimental and numerical analysis. The liquid flow Reynolds numbers, based on hydraulic diameters, were 11500 and 17000. The air flow Reynolds number varied from 0 to 3260. In experiments, velocity distribution was measured by hot-film and hot-wire probes. The effect of the liquid flow Reynolds number and the direction of interfacial shear stress was investigated by performing the cocurrent and countercurrent experiments. The modified k-{epsilon} model was able to reproduce these experimental results qualitatively. The range of applicability of the modified k-{epsilon} model was also discussed. (author).
Momentum transfer through an air-water interface was studied in a horizontal rectangular channel through experimental and numerical analysis. The liquid flow Reynolds numbers, based on hydraulic diameters, were 11500 and 17000. The air flow Reynolds number varied from 0 to 3260. In experiments, velocity distribution was measured by hot-film and hot-wire probes. The effect of the liquid flow Reynolds number and the direction of interfacial shear stress was investigated by performing the cocurrent and countercurrent experiments. The modified k-#epsilon# model was able to reproduce these experimental results qualitatively. The range of applicability of the modified k-#epsilon# model was also discussed. (author).
We define {\\em predictive information} $I_{\\rm pred} (T)$ as the mutual information between the past and the future of a time series. Three qualitatively different behaviors are found in the limit of large observation times $T$: $I_{\\rm pred} (T)$ can remain finite, grow logarithmically, or grow as a fractional power law. If the time series allows us to learn a model with a finite number of parameters, then $I_{\\rm pred} (T)$ grows logarithmically with a coefficient that counts the dimensionality of the model space. While logarithmic growth of related information theoretic quantities has been found in previous work on learning, power law growth has not been seen in this context. We find that it is associated, for example, with the learning of infinite parameter (or nonparametric) models such as continuous functions with smoothness constraints. There are connections between the predictive information and measures of complexity that have been defined both in ...
Google's Android is a comprehensive software framework for mobile communication devices (i.e., smartphones, PDAs). The Android framework includes an operating system, middleware and a set of key applications. The incorporation of integrated access services to the Internet on such mobile devices, however, increases their exposure to damages inflicted by various types of malware. This paper provides a comprehensive security assessment of the Android framework and the security mechanisms incorporated into it. A methodological qualitative risk analysis that we conducted identifies the high-risk threats to the framework and any potential danger to information or to the system resulting from vulnerabilities that have been uncovered and exploited. Our review of current academic and commercial solutions in the area of smartphone security yields a list of applied and recommended defense mechanisms for hardening mobile devices in general and the Android ...
Heavily doped emitters with low saturation current density are of particular interest for selective emitter solar cells. These emitters can be obtained by laser doping through the phosphosilicate glass layer formed after thermal diffusion from POCl3 gas. The experimental results show that in contrast to purely POCl3 furnace-diffused emitters, the saturation current density of laser-doped emitters does not increase linearly as sheet resistance decreases, but rather features two distinct regimes. In one of these regimes, the saturation current density is found to decrease as the sheet resistance decreases, reaching values lower than those of furnace emitters. This peculiar behaviour was explained by both qualitativeanalysis and numerical simulations.
Utilities are evaluating several electric generation and storage (G ampersand S) technologies for distributed utility (DU) applications. Attributes of leading DU technologies and implications for photovoltaics (PV) are described. Included is a survey of present and projected cost and performance for: (1) small, advanced combustion turbines (CTs); (2) advanced, natural gas-fired, diesel engines (diesel engines); and (3) advanced lead-acid battery systems (batteries). Technology drivers and relative qualitative benefits are described. A levelized energy cost-based cost target for PV for DU applications is provided. The analysis addresses only relative cost, for PV and for three selected alternative DU technologies. Comparable size, utility, and benefits are assumed, although relative value is application-specific and often technology- and site-specific.
The objective of this project was to implement a centralised data base of internal quality control in radiotherapy according to the criteria of the decree of A.f.s.s.a.p.s. (French agency of sanitary safety of health products on 27 july 2007, about the internal quality control of external radiotherapy facilities. The software on one year meets the objectives: compliance by comparison with A.f.s.s.a.p.s. criteria but particularly optimization of the centralisation and analysis of the internal quality controls. (N.C.)
The majority of research on homeless youth has focused on the multitude of problems faced by this vulnerable population. The current study, while acknowledging the hazards of life on the streets, seeks to explore the personal strengths and informal resources street youth rely on to navigate their environments. Qualitative data from seven focus groups conducted with street youth ages 18?24 were analyzed using content analysis. These data, rich with interactions among youth participants, highlight three important themes: developing ?street smarts,?? existence of personal strengths, and informal resources relied upon by youth to survive. Results provide valuable insights into the strengths of homeless youth that can be useful to providers in assessing street youths? service needs and increasi...
We report here a many-year study of the qualitative and quantitative content of flavonoids in the reproductive organs of the showy tick trefoil (Desmodium canadense (L.) DC., Fabaceae) - stems, leaves, buds, inflorescences,pods, and seeds - collected at different phases of growth at the Department of Medicinal Plants, Kaunas Botanical Garden, Vytautas Magnus University. HPLC studies identified 15 aglycone and glycoside flavonoids: apigenin, apigenin-7-O-glycoside, luteolin, rutin, vicenin-2, vitexin, isovitexin, vitexin rhamnoside, orientin, homoorientin, quercetrin, quercetin, hyperoside, astralagin, and kaempferol. The largest quantities of flavonoids in the vegetative organs from year 2 to year 4 of plant growth were present in the leaves (2.64% and 2.61% at budding and flowering in the...
In order to maintain a safe operation and availability of generating facilities, qualitative and quantitative assessment of piping vibration was performed vibration sources and damages of piping support was identified on the second piping system of Wolsung nuclear power plant unit 1 .Inspected piping supports and structures in both hot and cold condition .Established evaluation procedures of piping vibration .Performed the static analysis of 2 nd piping system .Established optimal vibration reducing method .The measured vibration level after installing rigid supports and energy absorbing type restraint was reduced about 7 times in velocity unit (author). 24 refs., 95 figs.
Background: As the global population ages, support for family caregivers who provide the bulk of care to community-dwelling older people is becoming ever more important. However, in many countries, homecare-service practitioners currently do not follow a systematic approach to assessing and responding to caregiver needs. Objectives: The aim of this study was to explore the experiences of caregivers and practitioners who took part in a field test of the Family Caregivers Support Agreement (FCSA) tool, a modified version of the Carers Outcome Agreement Tool (COAT) initially developed as the result of an Anglo-Swedish study. Both the COAT and the FCSA are designed to facilitate partnerships between caregivers and practitioners so that needs assessment and subsequent support services are negot...
A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the U.S. Department of Energy's remedial action survey programs. The unit consists of NaI(Tl) detectors housed in a specially equipped van. The system is operator controlled through an on-board minicomputer with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided on floppy disk. Multichannel analysis capabilities are included for qualitative radionuclide identification. A /sup 226/Ra-specific algorithm is currently employed to identify locations containing residual radium-bearing materials.
A mobile gamma-ray scanning system has been developed by Oak Ridge National Laboratory for use in the U.S. Department of Energy's remedial action survey programs. The unit consists of NaI(Tl) detectors housed in a specially equipped van. The system is operator controlled through an on-board minicomputer with data output provided on the computer video screen, strip chart recorders, and an on-line printer. Data storage is provided on floppy disk. Multichannel analysis capabilities are included for qualitative radionuclide identification. A "2"2"6Ra-specific algorithm is currently employed to identify locations containing residual radium-bearing materials.
A formula and technology are presented for the preparation of a hydrolyzed polyacrylonitrile (gipane) from the wastes of chemical production, analysis of the results of working to use them to insulate influxes of water in the extracting wells of the Sokolovogorskiy field.
Biomass fuel burning leads to high levels of suspended particulate matter and hazardous chemicals in the indoor environment in countries where it is in common use, contributing significantly to indoor...Full Text Available
A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemicalanalysis. (orig.). 2 refs.
Environmental surveys to provide base-line data for assessing the potential impact of the operation of Wolseong NPP on marine ecosystems were performed at 3-month intervals in 1981. Physico-chemical properties of seawater and gross beta activities in seaw...
Ammonium sulfate is produced from spent sulfuric acid from the production of alcohols. Certain mineral and organic impurities exist in the sulfuric acid that impair the quality of the ammonium sulfate. A detailed method for the chemicalanalysis for the impurities is presented.
The dynamical signals of sound pressure oscillation in natural convective subcooled boiling system are obtained by using computer data acquisition technique. Through frequency-domain analysis of typical dynamical data, combined with study on the acquired time series of sound pressure, are observed and explained. The time-frequency phenomena, such as the onset of shock wave, frequency doubling relation of sound pressure, combination of sound frequency spectrum peaks etc., which describe the characteristics of natural convective subcooled boiling system are presented. Furthermore, based on frequency spectra of sound pressure, related eigen vectors are defined and established and with dynamical clustering method, regime recognition for the dynamical process of system is carried out. Results of recognition are consistent with that of qualitativeanalysis of time series, which is of great significance for automatic monitoring ...
The automotive paints could be generally differentiated by color, layer sequence and chemistry of the paint layers comprising each of the topcoat and the primer system. The successful identification of hit-and-run a and traffic accidental vehicles from evidential paint fragments is greatly facilitated with a comprehensive laboratory collection of reference paint samples and the technique for direct analysis without sample preparation. The Pyrolysis-Gas Chromatography(PGC) is a precise and reliable method for performing both quantitative and qualitativeanalysis of polymeric materials and forensic samples. Our Forensic Laboratory is conducting the examination and identification of 73 reference paint samples; 4 colors of each domestic automotive make that is poplar in Korea, by Curie Point Pyrolyzer(JHP-3) and GC with capillary column(ultra alloy-5). This method can be used not only to compare paint traces with their ...
The Four years of the IMPACT, 'Integrated Modular Plant Analysis and Computing Technology' project Phase 1 have been completed. The verification study of Severe Accident Analysis Code SAMPSON prototype developed in Phase 1 was conducted in two steps. First, each analysis module was run independently and analysis results were compared and verified against separate-effect test data with good results. Test data are as follows: CORA-13 (FZK) for the Core Heat-up Module; VI-3 of HI/VI Test (ORNL) for the FP Release from Fuel Module; KROTOS-37 (JRC-ISPRA) for the Molten Core Relocation Module; Water Spread Test (UCSB) for the Debris Spreading Model and Benard's Melting Test for Natural Convection Model in the Debris Cooling Module; Hydrogen Burning Test (NUPEC) for the Ex-Vessel Thermal Hydraulics Module; PREMIX, PM10 (FZK) for the Steam Explosion Module; and SWISS-2 (SNL) for the Debris-Concrete Interaction ...
By increasing the price of crude oil and natural gas and the decline in their stock a possibility of more intense use of coal reserves as a feedstock not only for energy purposes but also as a feedstock source for other industries, mainly chemical and steel industry, is opening up. At present brown coal exploited in the Czech Republic is explicitly burned in the power sources of various outputs. Coal pyrolysis under the defined conditions may be an outstanding way of non-energetic brown coal processing. The target of our work was to determine the behaviour of various types of brown coal from the North Bohemian Basin under the pyrolysis up to the temperature 750{sup o}C. At the same time, qualitative parameters of the pyrolysis products in dependence on the features of the input brown coal were observed. Various types of brown coal were used for the pyrolysis tests differing mainly in the content of ash, sulphur and tar. Within the work mass ...
In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical ...
Localized beam-processed areas using chemical reactions induced by a 30 keV Ga"+ focused ion beam (FIB) with and without I_2 (etching) and (CH_3)_3CH_3C_5H_5Pt gases (Pt deposition) have been analyzed using a 300 keV Be"2"+ microprobe with a beam spot size of 50-80 nm. The analyzed results have been compared with energy dispersive X-ray (EDX) analysis using an electron beam. The EDX analysis only indicated incorporated impurities at high fluence such as Ga, Pt and C, while microprobe RBS analysis could detect residual iodine with low concentration which couldn't be detected by EDS analysis because of the lower sensitivity of the EDX analysis for heavy atoms.
Methods currently being used or developed for the elemental analysis of materials are chemicalanalysis, non-destructive inspection and calorimetry. The chemicalanalysis, which removes high-level radioactive elements through chemical treatments and then performs the quantitative analysis using the ICP-MS(Inductively Coupled Plasma - Mass Spectrometer) or the ID-MS(Isotope Dilution Mass Spectrometer), is recognized the most accurate. However, it requires a long, complex pre-treatment process in which a mass spectrometer could be contaminated. To solve this problem, a new method, which can be performed with high-level radioactivity and at high temperature, was desired. Such a method should also have the same accuracy as the chemicalanalysis, with a less possibility for instruments to be contaminated. ...
This is a progress report from the Health and Safety Research Division of Oak Ridge National Laboratory. Information is presented in the following sections: Assessment Technology, Biological and Radiation Physics, Chemical Physics, Biomedical and Environmental Information Analysis, Risk Analysis, Center for Risk Management, Associate Laboratories for Excellence in Radiation Technology (ALERT), and Contributions to National and Lead Laboratory Programs and Assignments--Environmental Restoration.
A short synopsis of each project is given covering the following main areas of research and development: Atmospheric sciences; Biotechnology; Chemical and instrumentation analysis; Computer and information science; Design and manufacture engineering; Ecological science; Electronics and sensors; Experimental technology; Health protection and dosimetry; Hydrologic and geologic science; Marine sciences; Materials science; Nuclear science and engineering; Process science and engineering; Sociotechnical systems analysis; Statistics and applied mathematics; and Thermal and energy systems.
Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed. (author).
Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed.
A new software for neutron activation analysis was designed, built and implemented on a desktop computer using Visual Basic 6.0 program. The construction of this data analyzer computer program is described. The new software deals with peak reports resulting from Gammaplus software with minimum interference from the user in order to save time, manpower and minimize human errors. Its ability to find the concentrations of chemical elements within samples is proven to be fast, reliable and user friendly. (author)
Analysis of damages done by the radiation in a polymer characterized by optic properties of polished surfaces, of uniformity and chemical resistance that the acrylic; resistant until the 150 centigrade grades of temperature, and with an approximate weight of half of the glass. An objective of this work is the development of a method that analyze in automated form the superficial damages induced by radiation in plastic materials means an images analyst. (Author)
BackgroundDiagnostic delay in patients with tuberculosis (TB) leads to ongoing TB transmission, higher mortality rates and increased patient and government health expenditure. Qualitative...Full Text Available
Nuclear forensic science has become increasingly important for global nuclear security. However, many current laboratory analysis techniques are based on methods developed without the imperative for timely analysis that underlies the post-detonation forensics mission requirements. Current analysis of actinides, fission products, and fuel-specific materials requires time-consuming chemical separation coupled with nuclear counting or mass spectrometry. High-temperature gas-phase separations have been used in the past for the rapid separation of newly created elements/isotopes and as a basis for chemical classification of that element. We are assessing the utility of this method for rapid separation in the gas-phase to accelerate the separations of radioisotopes germane to post-detonation nuclear forensic investigations. The existing state of the art for thermo chromatographic ...
In this study, sensitivity analysis of 100 MWth chemical looping combustion combined cycle (CLC-CC) plant based on fuel cost were performed. By performance analysis, net efficiency of natural gas/syngas fueled CLC-CC plant was 53-54%, corresponding to previous research. We used Chemical Engineering Plant Cost Index and Guthrie method to evaluate plant cost. For syngas fueled CLC-CC plant, the plant cost was higher since lower heating value (LHV) of syngas was lower than that of natural gas and cost of electricity (COE) was also higher since the cost of syngas was higher than that of natural gas. By sensitivity analysis, it was shown that the cost of syngas should be less than 5.3 $/GJ in order to make COE lower than 5.8 c/kWh which was COE of natural gas CLC-CC plant. 15 refs., 2 figs., 5 tabs.
The hydroelectric industry's recognition of the importance of avoiding unexpected failure, or forced outages, led to the development of probabilistic, or risk-based, methods in order to attempt to quantify exposures. Traditionally, such analysis has been carried out by qualitative assessments, relying on experience and sound engineering judgment to determine the optimum time to maintain, repair or replace a part or system. Depending on the nature of the problem, however, and the level of experience of those included in the decision making process, it is difficult to find a balance between acting proactively and accepting some amount of risk. The development of a practical means for establishing the probability of failure of any part or system, based on the determination of the statistical distribution of engineering properties such as acting stresses, is discussed. The capacity-demand analysis methodology, coupled ...
The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on grounds of economic efficiency and environmental quality. The fuel cell program is supported on grounds of ...
Fingerprinting of Penicillium crustosum strains was performed using different phenotypic characteristics. Seven strains of this extremely homogenous species were selected; of these, five originated from geographical locations characterized by low temperatures, and one from a location with a low water activity. Principal component analysis (PCA) was performed using micromorphological data, temperature- and water-dependent growth rates, and extrolite profiles obtained by HPLC analysis. The micromorphological data were less informative, while the growth-rate data were informative only if the strains investigated already showed slight adaptations to the selected external parameter. In contrast, PCA analyses of the extrolite data showed groupings of the strains according to their origins and known physiological differences. These groupings are in full agreement with the clustering obtained by previous amplified fragment length polymorphism (AFLP) ...
Complete factorization scheme analysis of $F_2^{\\gamma}(x,Q^2)$ in the next--to--leading order QCD is performed. It is shown that the presence of the inhomogenous term in the evolution equations for parton distribution functions of the photon implies qualitative change in the way factorization mechanism works in photon--hadron and photon--photon collisions as compared to hadron--hadron ones. The incompletness of the existing NLO analyses of $F_2^{\\gamma}(x,Q^2)$ is pointed out and its origins traced back to the misinterpretation of the behaviour of $q^{\\gamma}(x,M)$ as a function of in the LO photonic coefficient function $C_{\\gamma}^{(0)}(x)$ is given and smooth transition between the properties of virtual and real photon discussed. A simple way of avoiding the problems with the term $\\ln(1-x)$ appearing in the standard expression for $C_{\\gamma}^{(0)}(x)$ in the case of the reaal photon is proposed.
When the foundations of the building are designed and worked, the prediction calculation of immediate settlement of the building exercised practically is to calculate assuming the earth is a linear elastic body, but the actual stress-strain relationship of the earth is nonlinear and rigidity of the earth becomes lower as strain (or stress) increases. Hence in order to grasp the actual settling behavior of the earth, it is necessary to elucidate the nonlinear relationship between stress and strain. In this article, a prediction method of building settlement is introduced which uses an analytical technique of the multi-layered earth by the linear elasticity theory and takes into consideration strain dependency of rigidity of the earth. Part of the conclusion is as follows which has been obtained by studying the settling behaviors observed in examples of vertical loading tests of the pile foundations and the elasto-plastic settlement analytical method of the pile foundations; the settling ...
A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T {sub f}), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T {sub f} series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T {sub f} series. Thus the long-range correlation properties of the protein main chain ...
A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T _f), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T _f series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T _f series. Thus the long-range correlation properties of the protein main chain structure and ...
The Ho-Chunk Nation is interested in documenting water-quality conditions in streams adjacent to their Reservation lands in Wisconsin and developing management plans to protect these water resources. The Nation uses these waterways for recreation and as a source for food, and therefore, is dedicated to maintaining and restoring their quality. Ho-Chunk lands encompass more than 10,000 acres ranging primarily over 17 counties in Wisconsin. The study areas for this report include streams adjacent to Ho-Chunk Nation residential lands: Potch-Hah-Chee, Sandpillow, Mission, Bluewing, Chakh Hah Chee, Winnebago Heights, Indian Heights, and Ho-Chunk Village. These residential areas, or housing sites, are located along or near the Middle Branch Embarrass, Black, Lemonweir, and Wisconsin Rivers or their tributaries. Water-quality data were compiled and summarized, and basin maps showing land cover and previous sampling sites are presented. Qualitative assessments of factors ...
The authors compared unenhanced and contrast-enhanced fast MRI and Computerized Tomography in the detection of liver metastases. Eleven patients with single or multiple hepatic lesions (42 in all) were submitted to V and magnetic resonance studies; T1- and T2- weighted TSE, T2-weighted TSE with fat suppression, unenhanced breath-hold TFE and early or delayed enhanced breath-hold TFE images were acquired with a 1.5 T superconductive magnet (Philips NT). The quantitative analysis of all magnetic resonance images was performed for contrast/noise ratio (CNR) and number of detected lesions; magnetic resonance and Computerized Tomography images were also compared qualitatively for lesion conspicuity, anatomical structure identification and artifacts. The results were compared with Student's test. Early enhanced breath-hold TFE was statistically superior to T1-weighted TSE (p = .0009), T2-weighted TSE (p = .01) and Computerized Tomography ( p = .0004) ...
We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of crude oil. A primary motivation behind the work is to precisely measure the distillation curves of these oils using our advanced ...
Based on the instrumental wavelength dispersive X-ray fluorescence technique of analysis (W D-X R F), the inorganic elements in four samples of commercial medicines drugs were analyzed. The samples were used without any chemical separation of the elements or chemical pre-treatment. Eleven elements could be identified, namely Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu and Zn. However, Si, Ti and Mn have not been mentioned in the printed instructions for the use of the medicines drugs by the producers. (author)
Multiwall carbon nanotubes (MWCNTs) were functionalized with a photosensitizer, rosebengal (RB), and folicacid (FA), an anti-cancer drug simultaneously and individually, which was characterized with various analytical instruments like Fourier Transform Iinfrared (FTIR) spectroscopy, UV?Vis spectroscopy, Thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). FTIR spectra confirmed the chemical modification of MWCNT. The chemical functionalization of MWCNT with RB was further supported by UV?Vis and PL spectra.
The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.
Papers are presented under 38 symposia. Subjects included reinforced concrete, protective coatings and linings, cathodic/anodic protection, chemical cleaning of boilers, managing corrosion with plastics, water treatment, HRSG boiler tube failure analysis, corrosion in oil and gas production, corrosion in petroleum refining and gas, processing, pipelines and tanks, high temperature materials, chemical process industry, aerospace equipment, materials technology developments for incinerators and waste fuel-fired processors, materials and corrosion in fossil-fuels conversion and combustion, corrosion in nuclear systems, marine corrosion, building systems, corrosion mechanisms, corrosion inhibitors and corrosion monitoring and measurement.
In this work, the chemical transformations induced by 5 keV protons (10{sup 6} ion cm{sup -2}) at the surface of 0.4 {mu}m polyacrylonitrile and polymethacrylonitrile films are analysed by XPS and IRRAS. Spectroscopic changes in both the polymers are globally similar, the most significant feature being a lower relative concentration of nitrogen with respect to carbon closer to the surface. Quantitatively, this change is more marked in the case of polyacrylonitrile which suggests a direct relation with the hydrogen in {alpha} to the nitrile function.
The paper reported the results of fiscal 1994 studies on solar energy in the New Sunshine Project. Relating to the technical development for the practical use of photovoltaic power systems, the development of manufacturing technologies for low-cost substrates and the development of element technology for manufacturing low-cost polycrystalline cells/modules were reported as the development of technology for thin substrate polycrystalline solar cells for practical use. As to the research on fabrication technology for thin film solar cells for practical use, reports were made on the research on low-cost fabrication technology for large-area modules and the technological development for qualitative improvement, etc. In respect to the technological development for super-high efficiency solar cells, reported were the technological development for super-high efficiency single crystalline silicon solar cells and the technological development for crystalline compound solar ...
The thermo-chemical treatments of steels with plasma is normally carried out in low-pressure ionized gaseous atmospheres. Among the treatments used most often are: nitruration, carburization and boronized. A plasma can also generate at atmospheric pressure. One way to produce it is with an electrochemical cell that works at a relatively high inter-electrode voltage and under conditions of heavy gas generation. This type of plasma is known as electrolytic plasma. This work studies the feasibility of using electrolytic plasma for the surface processing of steels. Two processes were selected: boronized and nitruration., for the hardening of two types of steel: one with low carbon (1020) and one with low alloy (4140). In the case of the nitruration, the 1020 steel was first aluminized. The electrolytes were aqueous solutions of borax for the boronizing and urea for the nitruration. The electrolytic plasmas were classified qualitatively, in relation ...
Indium sulfide thin films consisting of porous network of nanoplatelets, have been deposited using chemical bath deposition (CBD) method onto the tin-doped indium oxide (ITO) coated glass substrate. Aqueous solutions of indium sulfate and thioacetamide have been used as indium and sulfur precursors. As a complexing agent, acetic acid was used. The chemically deposited indium sulfide thin films were examined for their structural, surface morphological and optical characterizations. The X-ray diffraction analysis revealed the formation of the cubic b-In2S3 onto the substrate. From scanning electron micrograph, it is observed that the surface of substrate is covered by nanoporous platelets type morphology. The optical studies showed a direct band gap of 2.84eV for indium sulfide platelets. Ph...
A renewed interest in chemical fractionation of soil organic matter (SOM) originates from the premise that it enables to isolate labile SOM from SOM protected through mineral binding and recalcitrant SOM. Both selective removal of labile non-bound SOM through oxidation or hydrolysis as well as selective removal of minerals and attached SOM are often applied. Molecular-level SOM characterization by means of temperature resolved Pyrolysis-Field Ionization Mass Spectroscopy analysis (Py-FIMS) was used here as an approach to obtain insight into the fate of SOM upon wet chemical treatment with regard to composition and thermal stability. The applied sequential chemical treatment with 6% NaOCl and 10% HF yielded similar sizes in stable SOM fractions between sandy semi-native heathland and cultiv...
This paper reports the chemical compositions of chicken-blood stone Ji Xue Shi measured by Proton Induced X-ray Emission (PIXE). The experimental result show that for the red portion of chicken-blood stone, the concentration of Hg is as high as 20 wt%, and the concentration of S can be above 10 wt%. For the non-red portion the main chemical compositions are Al{sub 2}O{sub 3} and SiO{sub 2}. The obtained chemical compositions are close to those of kaolinite for Balin chicken-blood stone, and of pyrophyllite for Changhua chicken-blood stone, respectively. So far many Changhua chicken-blood stones and Balin chicken-blood stones were found in China, the PIXE method can be used to explore the provenance of available chicken-blood stones. (author)
Purpose To study the chemical modifications induced upon irradiation of solid human insulin at radiosterilization doses and investigate the influence of the absorbed dose on radiolysis. Materials and Methods Volatile radiolytic products were monitored by gas chromatography coupled with mass spectrometry (GC-MS) and non-volatile products by two different high performance liquid chromatography (HPLC) methods: the formation of higher molecular weight proteins was assessed by size exclusion liquid chromatography whereas assays for related compounds and chemical potency tests were carried out using reverse-phase HPLC-UV. Conformational changes were investigated by measurements of circular dichroism. Results After gamma irradiation at 10?kGy, the recovery of insulin was 96.8%; higher molecular w...
This current work is concerned with the development of polypropylene composites reinforced with cellulose and cellulignin fibers attained from sugarcane bagasse. Moreover, the fibers were chemically modified by acetylating process and its effects on the fiber/matrix interaction were also evaluated. The chemical modification efficiency was verified by FTIR analysis and the fibers morphological aspects of fibers by SEM. Likewise, the influence of modified fibers content in the composites was studied by mechanical (tensile, shear and flexural tests) and thermal analyses (TGA and DSC). After the chemical modification, the FTIR results showed the appearance of acetyl groups and reduction of OH bonds for all fibers. Together with, SEM characterization showed that the acetylation changed the morp...
The Cs-137 radioactivity of a neutron-irradiated nuclear fuel sample has been measured by means of a micro-gamma scanning system which is associated with a high purity Ge detector. Subsequently the burn-up has been calculated from the Cs-137 radioactivity data and then compared with the values from the theoretical computation and chemical anaylsis. The burn-up value obtained with the gamma-scanning system seems to be reasonably agreeable with that of the chemical anaylsis provided that the statistical error in the experiments is taken into account. It is revealed that the burn-up data from the theoretical approach is slightly higher than those of micro-gamma scanning and chemicalanalysis methods. (Author).
The purpose of this study was to investigate whether the expression of specific genes in peripheral blood can be used as surrogate marker(s) to detect and distinguish target organ toxicity induced by chemicals in rats. Rats were intraperitoneally administered a single, acute dose of a well-established hepatotoxic (acetaminophen) or a neurotoxic (methyl parathion) chemical. Administration of acetaminophen (AP) in the rats resulted in hepatotoxicity as evidenced from elevated blood transaminase activities. Similarly, administration of methyl parathion (MP) resulted in neurotoxicity in the rats as evidenced from the inhibition of acetyl cholinesterase activity in their blood. Administration of either chemical also resulted in mild hematotoxicity in the rats. Microarray analysis of the global ...
The objective of the present work is to study the chemical variation in Calophyllum inophyllum growing along the Western Ghats of India. Contents of dipyranocoumarins (inophyllums) in C.?inophyllum were determined to assess whether they could be used as a taxonomic marker for C.?inophyllum. This study also aims to establish inter simple sequence repeat (ISSR) markers that can be used to study genetic variation within the species and explore correlation between ISSR and chemical markers. The contents of dipyranocoumarins were estimated in seeds collected from 20 locations. Leaves from plants at the same 20 locations were assayed for ISSR variation. A dendrogram based on Nei?s genetic distance as well as principal component analysis based on dipyranocoumarins and ISSR variation clustered pla...
Objectives1. To establish the present capacity and capability across all the sectors within the UK for - a) Undertaking research in the areas of toxicology and ecotoxicology and environmental hazard and risk assessment work on chemical subtances including emerging containments (e.g. enginerred nanomaterials); and b) Applying these skills in the policy and regulatory context. 2) The range of chemicals involved should include pharmaceutical and medical products, crop protection agents, biocides, vet [continued...]DescriptionThe aim of this project is to identify the current status of the scientific community, areas of expertise, and identify the gaps in skills, knowledge or recruitment. The project will use a questionnaire approach to obtain this information for all sectors of the business community. The analysis will identify the gaps in provision, and areas where investment is needed in future training and/or recruitment.
Abstract Steam generation is an integral part of most chemical process plants; however, the steam plant often is or can be overlooked in the area of hazard analysis. The reasons for this oversight are obvious: steam generation is considered to be an old and well-understood process, and steam boiler systems are often not considered to pose the same hazards as other plant units. However, modern steam boiler systems are fueled with natural gas, pulverized coal, and/or fuel oil; each of which poses significant fire and explosion hazards. For example, a moderately sized chemical plant's boiler house may have two or three boilers operating at 240 MMBTU/hr, with each using approximately 11 ton/hr of subbituminous pulverized coal feed. Chemical plants rely on equipment design and installation, mai...
A sensitivity analysis was conducted to evaluate the technical issues pertaining to possible destructive interactions between spent nuclear fuels (SNFs) and the stainless steel canisters. When issues are identified through such an analysis, they provide the technical basis for answering what if questions and, if needed, for conducting additional analyses, testing, or other efforts to resolve them in order to base the licensing on solid technical grounds. The analysis reported herein systematically assessed the chemical and physical properties and the potential interactions of the materials that comprise typical US Department of Energy (DOE) SNFs and the stainless steel canisters in which they will be stored, transported, and placed in a geologic repository for final disposition. The primary focus in each step of the analysis was to identify any possible phenomena that could ...
The 1.7 billion pounds of benzene produced each year in the US provide one measure of its utility. At the same time, there are a number of environmental reasons for avoiding the use of benzene in chemical manufacture. Perhaps most compelling: benzene is a potent carcinogen. Scrutiny of many of the chemicals derived from benzene reveals that each molecule contains at least one oxygen atom while benzene completely lacks oxygen atoms. Introduction of oxygen to make up for this lack can require processes that are environmentally problematic. One of the steps used to introduce oxygen atoms during manufacture of adipic acid, a component of Nylon 66, is responsible for 10% of the annual global increase in atmospheric nitrous oxide. This by-product is a causative agent of atmospheric ozone depletion and has been implicated in global warming. With support from EPA and the National Science Foundation, alternative manufacturing processes are being ...
This report summarizes the results of an expert-opinion elicitation activity designed to qualitatively assess the status and capabilities of currently available computer codes and models for accident analysis and reactor safety calculations of advanced sodium fast reactors, and identify important gaps. The twelve-member panel consisted of representatives from five U.S. National Laboratories (SNL, ANL, INL, ORNL, and BNL), the University of Wisconsin, the KAERI, the JAEA, and the CEA. The major portion of this elicitation activity occurred during a two-day meeting held on Aug. 10-11, 2010 at Argonne National Laboratory. There were two primary objectives of this work: (1) Identify computer codes currently available for SFR accident analysis and reactor safety calculations; and (2) Assess the status and capability of current US computer codes to adequately model the required accident scenarios and associated phenomena, and ...
Different types of radioactive liquid waste are being generated at Advanced Fuel Fabrication Facility (AFFF), Tarapur during the quality control analysis of the mixed oxide (MOX) fuel pellets. A laboratory scale study was performed for treatment of such waste. Some of the waste streams originating from U and Pu analysis contain components like sulphate and phosphate which interfere during chemical precipitation of alpha activity from the waste. Various chemical co-precipitation experiments were conducted based on alkaline precipitation. Reductive precipitation using sodium sulphite and Fe(II) was found to be promising and the same was suggested for plant scale treatment. (author)
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, wh...
This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to ...
A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%. (author)
A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat e...
The problems are discussed of using radionuclide X-ray fluorescence analysis (the most frequently used source is "2"4"1Am) and neutron activation analysis for monitoring the chemical quality of the working environment of a welder. Elements determinable by these methods are listed and the advantages of the methods stated with regard to speed, simplicity and appropriate accuracy of measurement together with commercial availability of the instruments. Welding as a source of harmful substances is assessed by determination of the amount of chromium in aerosols generated by welding austenitic chromium-nickel steels. The described methods allow to obtain a complex image of the chemical nature of welding aerosols and to understand the mechanism of their impact on the human organism. (J.C.).
Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the pits via crystal phase orientation mapping, while 3D profilometry gave information on the depth and size ...
The aims of this study are determining the energy use, qualitative analyzing of energy flow and also investigating energy efficiency by Data Envelopment Analysis (DEA) in corn production of Iran during a seven years period. Results indicated that the average of total energy input increased from 40.98 GJ ha-1 in 2001 to 63.64 GJ ha-1 in the year of 2007. Similarly, the average of total output energy rose from 89.03 to 107.54 GJ ha-1 in the same years, respectively. Also the results showed that average energy use efficiency, energy productivity, specific energy and net energy gain in the studied period was 2.59, 0.17 kg MJ-1, 7.24 MJ kg-1 and 51.34 GJ ha-1, respectively. DEA considered the yield (kg ha-1) as output and three major energy inputs; fertilizers, diesel fuel and machinery as inpu...
College student persistence and dropout have been studied for decades, but little inquiry has focused on community college or private two-year college students. Although about half of first-time postsecondary students enroll in a two-year college, researchers understand little about why only approximately a quarter of these degree-seekers complete any degree five years after entrance (Rosenbaum, Deil-Amen, & Person, 2006). Models that exist have been generated primarily from research on residential, four-year college students. The present analysis uses rich qualitative data to excavate the potential of Tinto's Theory of Student Departure for understanding the dynamics of persistence for a more nontraditional group--two-year college commuting students. To better reflect how these students successfully cultivate feelings of belonging and competence, reinforce goal commitment, and access valuable social capital, a new conceptual fusion of the ...
This issue of Barrages newsletter comprises three articles. The first article treats of the quality approach relative to the organization of the inspections of big and medium size dams. It summarizes the improvements of this approach added in 2003 after analysis of the experience feedback. The second article presents the conclusions of the decennial and annual inspections of dams in exploitation. Only the observations requiring a special follow-up are reported. The last article summarizes the activities of the control services for the third quarter of 2003: decennial and annual visits, important facts, administrative instructions, studies, projects and works, organization of services, technical studies etc.. (J.S.)
The need for noninvasive sensitive techniques for the diagnosis and follow-up of metabolic bone disease in dialysis patients has stimulated the author's interest in the efficacy of more detailed quantitative bone scintigraphy. Using hemodialysis to reduce elevated soft-tissue activity at scintigraphy, an attempt was made to assess the diagnostic sensitivity of quantitative bone scintigraphy as compared to qualitative bone scintigraphic, biochemical, radiographic and bone histologic studies. The second aim of these studies was to determine if one of the two major components of renal osteodystrophy is a major determinant for skeletal radiotracer uptake. The clinical observations on the efficacy and possible specificity of quantitative bone scintigraphy in the diagnosis and follow-up during treatment of renal osteodystrophy are presented briefly in this chapter. Thus, the use of scintigraphy for the routine detection and follow-up of renal osteodystrophy in dialysis ...
The statistical properties of the bid-ask spread of a frequently traded Chinese stock listed on the Shenzhen Stock Exchange are investigated using the limit-order book data. Three different definitions of spread are considered based on the time right before transactions, the time whenever the highest buying price or the lowest selling price changes, and a fixed time interval. The results are qualitatively similar no matter linear prices or logarithmic prices are used. The average spread exhibits evident intraday patterns consisting of a big L-shape in the morning and a small L-shape in the afternoon. The distributions of the spread with different definitions decay as power laws. The tail exponents of spreads at transaction level are well within the interval $(2,3)$ and that of average spreads are well in line with the inverse cubic law for different time intervals. Based on the detrended fluctuation analysis, we find evidence of long memory in ...
Excitation functions (EFs) for the reaction "1"4"1Pr(#alpha#, n)"1"4"4Pm and "1"4"1Pr(#alpha#, 2n)"1"4"3Pm have been measured using "1"4"1Pr as a target up to 50 MeV #alpha#-particle energy. Stacked foil activation technique and #gamma#-ray spectroscopy using 100 cm"3 Ge (Li) detector, has been used. Excitation functions are also calculated theoretically using Blann's geometry dependent hybrid (GDH) model code ALICE-91, with and without inclusion of pre-equilibrium particle emission. It has been observed that high-energy tails of the EFs are dominated by pre-equilibrium reaction mechanism. With the accepted set of input parameter, initial exciton number n_0=4 (2p + 2n + 0h), a good qualitative agreement is found. However, quantitative agreement for this magic nucleus"1"4"1Pr is also good when theoretical calculations are normalized by a multiple factor of 0.5. (author)
To systematically analyze the dynamical implications of the matter content in cosmology, we generalize earlier dynamical systems approaches so that perfect fluids with a general barotropic equation of state can be treated. We focus on locally rotationally symmetric Bianchi type IX and Kantowski-Sachs orthogonal perfect fluid models, since such models exhibit a particularly rich dynamical structure and also illustrate typical features of more general cases. For these models, we recast Einstein's field equations into a regular system on a compact state space, which is the basis for our analysis. We prove that models expand from a singularity and recollapse to a singularity when the perfect fluid satisfies the strong energy condition. When the matter source admits Einstein's static model, we present a comprehensive dynamical description, which includes the qualitative asymptotic behavior, of models in the neighborhood of the Einstein model; the ...
The Moderator Temperature Coefficient of reactivity (MTC) was earlier proven to be properly determined via noise analysis when the neutron noise is measured locally and when the radial average of the moderator temperature noise is used. Nevertheless, measurements revealed that the MTC was correctly estimated on a much narrower frequency band (0.6 - 0.7 Hz) than expected (0.1 - 1.0 Hz). The present paper investigates the effect of the feedback on the MTC determination using this new MTC noise estimator (which could explain the deviation at low frequencies, i.e. between 0.1 - 0.5 Hz) and the effect of the detector time constants (which could explain the deviation at high frequencies, i.e. between 0.7 - 1.0 Hz). For that purpose, a coupled neutronic/thermalhydraulic model of the Ringhals-3 PWR is developed in the frequency-domain, based on a radial 2-dimensional heterogeneous representation of the core. The transfer function of the detectors is also modelled in this ...
Hepatobiliary scintigraphy is the only non-invasive technique providing real-time assessment of hepatocytes function and bile progression from the liver to the intestine; for this reason it is of great importance in the study of jaundice and many other disorders of the liver and the biliary tract in children. Ultrasonography is the initial method of evaluating the intra- and extrahepatic bile ducts dilatation: the differential diagnosis between biliary atresia and neonatal hepatitis cannot however be done without hepatobiliary scintigraphy. Cystic fibrosis patients also require hepatobiliary scintigraphy; liver and biliary tract disease can really occur independently of the underlying disease severity and the presence of steatorrhoea. Hepatobiliary imaging in children who have undergone liver transplantation is of major importance; it can assess vascularity, parenchymal function biliary drainage, possible presence of a bile leak and obstruction; it has very good sensitivity and ...
The prediction of two-phase flow regime in the horizontal pipings during a loss-of-coolant accident (LOCA) is important for safety analysis of a pressurized water reactor (PWR). The flow regime transition conditions for a horizontal two-phase air-water flow were studied using a large-height, horizontal rectangular duct test section. The duct dimensions were 700 mm in height, 100 mm in width and 28.3 m in length. The experimental criterion for the flow regime transition from the stratified to slug flow regimes, in terms of the local void fraction and the non-dimensional gas-liquid relative velocity, agreed qualitatively with the prediction by the Mishima-Ishii model that is based on an idea that the interfacial waves with the largest growth rate will develop into a slug. However, the transition in the experiment occurred at systematically lower (by about 40 %) relative velocities than the prediction by the Mishima-Ishii model. Therefore, an ...
Not long ago primary census data became available to publicity. It opened qualitatively new perspectives not only for researchers in demography and sociology, but also for those people, who somehow face processes occurring in society. In this paper authors propose using Data Mining methods for searching hidden patterns in census data. A novel clustering-based technique is described as well. It allows determining factors which influence people behavior, in particular decision-making process (as an example, a decision whether to have a baby or not). Proposed technique is based on clustering a set of respondents, for whom a certain event have already happened (for instance, a baby was born), and discovering clusters' prototypes from a set of respondents, for whom this event hasn't occurred yet. By means of analyzing clusters' and their prototypes' characteristics it is possible to identify which factors influence the decision-making process. Authors also provide an ...
Abstract Coordination compounds [Ru(acac)2(Q)] (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a RuIII/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3- possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasi...
The DOE is conducting a comprehensive technical analysis of a flexible-fuel transportation system in the United States -- that is, a system that could easily switch between petroleum and another fuel, depending on price and availability. The DOE Alternative Fuels Assessment is aimed directly at questions of energy security and fuel availability, but covers a wide range of issues. This report examines environmental, health, and safety concerns associated with a switch to alternative- and flexible-fuel vehicles. Three potential alternatives to oil-based fuels in the transportation sector are considered: methanol, compressed natural gas (CNG), and electricity. The objective is to describe and discuss qualitatively potential environmental, health, and safety issues that would accompany widespread use of these three fuels. This report presents the results of exhaustive literature reviews; discussions with specialists in the vehicular and ...
Capacitance dispersion on the fractal carbon electrode with edge and basal orientations was investigated using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and a.c.-impedance spectroscopy. For this purpose, four types of as-received pyrolytic graphite electrode, as-received, mechanically polished, and as-activated glassy carbon electrodes were prepared with different surface irregularities and amounts of edge orientations. The apparent self-similar fractal dimensions of the carbon electrodes were determined from the analyses of AFM images based upon triangulation method. The amounts of edge orientations on the surface of the carbon electrodes were qualitatively estimated from the XPS analysis of surface acidic functional groups that were preferably formed on the edge planes by the heat treatment of the carbon electrodes. The values of the constant phase element exponent {alpha} determined from the apparent self-similar ...
New methodologies for fabrication of multilevel packaging, particularly for RF signal analysis, are investigated. A new method for ``gluing'' silicon wafers together with a Self Assembled Monolayers (SAMs) based nanoglue are discussed, as are methods to enable its use with nonconforming wafers. Results of bond strength measurements as a function of temperature and process will be presented. Surface area bonded is characterized by infrared (IR) imaging. We will also present a method of inducing self-alignment between whole silicon wafers with micrometer precision. This represents a qualitative departure from alignment of millimeter-sized object as has been previously demonstrated. Self-alignment is induced by creating hydrophilic and hydrophobic regions on the wafers and using capillary forces of water in these regions to force the wafers to align with little to no outside influence. Results are characterized by IR imaging. Physical ideas that ...
In order to perform the structural analysis and stress evaluation for frame structures in the nuclear power plants, ADAMS (AIJ Design Analysis and Modules System) has been developed by the addition of the following functions to the ICES-STRUDL system. 1. Load combination and stress evaluation on the basis of specifications for designing steel structure (issued by the Architecture Institute of Japan). 2. Combination of load and stress evaluation of piping support on the basis of the regulations of Ministry of International Trade and Industry. 3. Addition of other functions than that described above. ADAMS enables structural analysis and stress evaluation exactly and efficiently not only for a large scale structure such as the pipe whip protection structure installed inside of the primary containment vessel for many loading cases but also for a large number of structures such as piping support. This system can be applied not ...
Nuclear and other radioactive materials may get smuggled into the country aimed at malicious acts. Radioactive material detected accidentally or during inspection at the entry points/national borders may indicate illicit trafficking for the purpose of nuclear/radiological terrorism. As country requires prevention and preparedness for response to these malicious acts, nuclear forensic techniques are to be developed incorporating radiological safety aspects. Nuclear forensics helps in determining the origin, intended use, legal owner and the smuggled route etc. by using fingerprinting as well as comparison with reference data. The suggested sequence of methods for analysis of radioactive material/samples will be radiological assessment, physical characterization, traditional forensic analysis, isotope analysis along with elemental/chemicalanalysis
Canadian railway traffic is delayed until lines are plowed of snow following heavy snowfalls. A modification that would permit higher plowing speeds and fewer delays could realize significant benefits in addition to direct fuel and labor savings. The objective of this project was to carry out a cost benefit analysis on a low-friction coating applied to a mainline railway snow plow. The assessment was carried out using old Canadian National Railway snow plows for test purposes. An analytical model was developed to estimate the importance of friction reduction to fuel consumption and power requirements. The sensitivity analysis revealed a bump or discontinuity in the power vs speed profile, corresponding to the minimum plow speed at which the snow will cease to flow over the plow. Reducing the coefficient of friction reduces this minimum plowing speed. This could mean the difference between success and failure in plowing some tight, heavily laden ...
Coal direct chemical looping (CDCL) substitutes the gasification process in syngas chemical looping (SCL), thus eliminating the need for higher oxygen consumption. In this study, operating conditions are assessed for CDCL and SCL, directed towards hydrogen production from coal. The main objective is to increase the overall H{sub 2}/CO{sub 2} ratio for a given amount of coal, based on the various conditions. The operating variables considered as part of a resource optimization analysis include: (i) inlet conditions to the primary reactors, (ii) minimum resource requirements (air, steam and iron oxide), (iii) hydrogen-to-component ratios, and (iv) effect of coal carrier gas. The results suggest that CDCL has a higher hydrogen-to-CO{sub 2} ratio than SCL along with advantages such as low overall resource requirements (steam and air) and fewer intermediate processes. The coal carrier gas affects the hydrogen production only in ...
Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical ...
In this article, we review and clarify some of the points made by previous authors regarding chemical looping combustion (CLC). While much of the recent interest in chemical looping combustion has been associated with carbon sequestration, our primary interest here is its potential to increase the thermodynamic efficiency of converting fuel chemical energy into useful work. We expand on several points about the details of CLC that we feel have not previously been sufficiently explored, and suggest alternative (and possibly more practical) approaches that exploit some of the same thermodynamic concepts. We illustrate our key points with {First} and {Second} Law analyses of ideal conceptual processes, which in addition to {CLC} also include isothermal, non-equilibrium, preheated combustion and combustion with thermochemical recuperation. Our results suggest that a significant portion of the potential efficiency benefit of CLC ...
Wet limestone scrubbing is once again becoming a popular technology for removal of sulfur dioxide (SO{sub 2}) from power plant emissions. Critical to the operation of wet limestone flue gas desulfurization (FGD) systems is accurate chemicalanalysis of scrubber solids. The analytical technique of thermogravimetry is ideal for this application, as the instrument can give precise readings of the principal scrubber solids components, calcium sulfite/sulfate hemihydrate, calcium sulfate dihydrate (gypsum), and unused calcium carbonate. The data provides plant chemists, engineers, and operators with information needed to fine-tune scrubber operation and detect process upsets. (orig.)
Double-crystal high-resolution x-ray fluorescence spectrometry was applied to the state analysis of sulfur in coal and related fly ash. For total sulfur, a proportional relationship exists between fluorescence intensities and the analytical values obtained by the oxygen-combustion method. Two oxidation states of sulfur were identified by a least square curve fitting method, by assuming that the spectrum profile is identical for each sulfur state but the intensity and position are different. The chemical state of sulfur in coal and remaining in fly ash is discussed.
Microwave Electron Cyclotron Resonance (ECR) Plasma assisted Chemical Vapor Deposition (CVD) technology has been used to prepare Si_3N_4 films, which were analyzed by using infrared (IR) transmission spectroscopy and XPS. The analysis results show that with the increase of the deposition temperature, the H content decrease, and the densification of the film increases. When the temperature is up to 360 degree C, the stoichiometrical rate of Si:N is close to 0.75. The protective property of Si_3N_4 films is also examined
The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).
This paper presents the results of a model for the impact of potential contamination produced by radionuclide leaking due to long-term physical, chemical and hydrogeological processes occurring in a LILW repository and in the natural environment. The analysis contains a deterministic and also a probabilistic approach for uncertainty assessment. The input function, i.e., the source term was evaluated by using AMBER code and the entire analysis was accomplished by using GOLDSIM, a powerful tool to support probabilistic simulation in management and decision-making in engineering and science. The results obtained were compared to previous simulations and uncertainty analyses (FEHM). (authors)
A software called KEPCO RCM workstation (KRCM) has been developed to optimize the maintenance strategies of Korean nuclear power plants. The program modules of the KRCM were designed in a manner that combines EPRI methodologies and KEPRI analysis technique. The KRCM is being applied to the three pilot system, chemical and volume control system, main steam system, and compressed air system of Yonggwang Units 1 and 2. In addition, the KRCM can be utilized as a tool to meet a part of the requirements of maintenance rule (MR) imposed by U.S. NRC. 3 refs., 4 figs. (Author)
This study of the inorganic chemical composition of 10 different Nigerian medicinal plant species, using the technique of instrumental neutron activation analysis (INAA), resulted in the determination of the concentrations of 18 major, minor, and trace elements: Al, Ba, Br, Ca, Cl, Eu, Fe, Ga, K, La, Mn, Na, Sb, Sc, Si, Sm, V, and Zn. The parts of the plants used were roots, leaves, and bark. The NBS SRM 1571 Orchard Leaves was also analyzed to assess the accuracy of the procedures used. 21 refs., 4 tables.
During 1983, Oak Ridge National Laboratory continued a study of materials performance at the Wilsonville, Alabama, Advanced Coal Liquefaction Research and Development Facility. Materials performance was evaluated by exposure and analysis of corrosion coupons and U-bend specimens, chemicalanalysis of related process streams, and ultrasonic determination of the thickness of walls of various components. The results of these studies are useful to current plant operators and to designers of future large-scale plants. 18 references, 4 figures, 12 tables.
This report describes the sampling and chemical analyses of smoke gas components for combustion performed in the SP Industry Calorimeter, where continuous measurements of oxygen, carbon dioxide and carbon monoxide are an integrated part of the Calorimeter system. On-line measurements of nitrogen oxides and total amounts of unburnt hydrocarbons were performed. Hydrogen cyanide, hydrogen chloride and ammonia in the smoke were sampled and absorbed in impinger bottles and subsequently analyzed using wet chemical techniques. An adsorbent sampling system was designed to allow the identification and quantitative analysis of individual organic compounds in the smoke. Gas chromatography was utilized with a mass spectrometric detector for the identification and a FID for quantification of the total amounts as well as individual components. A procedure for cleaning the smoke gas duct in between the combustion experiments was designed ...
The aim of the classical multiple test strip is to perform routine chemicalanalysis in one single operation, yielding maximum diagnostic and prognostic information. A maximum of 10 test areas should not be exceeded. The efficiency of the currently marketed test strips is discussed and improvements within acceptable price limits are suggested. PMID:10841930
Thermodynamic analysis of dissolution processes of tungsten minerals in citric acid solutions in the absence and in the presence of hydrochloric acid has been carried out by means of calculation of Gibbs energy of the chemical reactions. Kinetic characteristics, such as specific dissolution rates and activation energies, are determined. It is established that the dissolution reactions studied take place in kinetic region. A possibility of scheelite selective dissolution in the presence of other tungsten minerals is shown.
Chemical contamination can be one of the more common problems encountered when performing trace-level analysis regardless of the analytical technique. Minimizing or eliminating background interferences...Full Text Available
Results are described of the study of the analytical applicability of a highly efficient ion source developed for a mass spectrometer. Its ionizer is in the form of a partially closed cavity with a small aperture for leading out ions, heated to a high temperature. The new ion source increases the sensitivity of the apparatus in operations with transuranium elements by almost two orders of magnitude. It is possible to perform isotopic analyses with a high salt content in the sample, and to study the characteristics of nuclear fuel, even without chemical separation of the sample elements.
Radionuclide x-ray fluorescence method was used in the determination of Cr, Ni and other heavy metals content in wastewater of an engineering plant taken both before and after chemical treatment. Toxic effects of the wastewaters using Allium cepa root tip cells were tested. (author) 8 refs.; 2 tabs.
A case study is presented about the failure of a stainless steel blade reinforcing band in a steam turbine. The inspection results and analysis of samples of material are discussed. Being pitting corrosion and cracks the main defects found, a study of chemical composition and heat treatment state of the steel is made and findings are related to type of failure. (orig.)
In this study, an apparatus suitable to photoacoustic (PA) imaging to measure blood-analysis and urinalysis is fabricated and its measurement scheme has been established for the first time. The PA imaging of urinalysis test strip, blood sugar test strip, and cholesterol test strip is performed. A calibration curve of PA measurement is obtained for a urine test strip. The detectivity is better than that obtained by an eye-measurement.
This document provides a technical basis for the revision of chemical effluent limitations guidelines for the Steam Electric Power Industry reflecting the Best Available Technology Economically Achievable (BATEA) for existing sources, New Source Performance Standards (NSPS) and Pretreatment Standards. The analysis of pollutants and the technologies applicable to their control has been based on specific waste streams of concern.
This paper describes the application of the instrumental analytical methods: neutron activation techniques, atomic absorption spectroscopy and flame emission spectroscopy, used to analyse some home-made teas, determining Na, K and Cl and comparing the results. This study verify whether the home-made teas used for rehydration of the children reach the composition recommended by WHO (World Health Organization). (author). 6 refs., 6 tabs.
Coke production from bitumens, coal, petroleum and lignite is covered in this compilation from worldwide research. Studies on coke oven design, performance, corrosion, and deterioration are cited. Blast furnace coke, additives, quality control, and chemicalanalysis are discussed. Byproduct recovery from coking processes is included. (This updated bibliography contains 369 citations, 110 of which are new entries to the previous edition.)
Coke production from bitumens, coal, petroleum and lignite is covered in this compilation from worldwide research. Studies on coke oven design, performance, corrosion, and deterioration are cited. Blast furnace coke, additives, quality control, and chemicalanalysis are discussed. Byproduct recovery from coking processes is included. (This updated bibliography contains 259 abstracts, 49 of which are new entries to the previous edition.)
Coke production from bitumens, coal, petroleum and lignite is covered in this compilation from worldwide research. Studies on coke oven design, performance, corrosion, and deterioration are cited. Blast furnace coke, additives, quality control, and chemicalanalysis are discussed. Byproduct recovery from coking processes is included. (This updated bibliography contains 210 abstracts, 61 of which are new entries to the previous edition.)
Coke production from bitumens, coal, petroleum, and lignite is covered in this compilation from worldwide research. Studies on coke oven design, performance, corrosion, and deterioration are cited. Coal effective utilization, blast furnace coke, additives, quality control, and chemicalanalysis are included. Byproduct recovery from coking processes is included. (Contains 150 abstracts)
We have studied the nucleation and growth processes in a chemical vapor deposition (CVD) diamond film using a tomographic electron backscattering diffraction method (3D EBSD). The approach is based on the combination of a focused ion beam (FIB) unit for serial sectioning in conjunction with high-resolution EBSD. Individual diamond grains were investigated in 3-dimensions particularly with regard to the role of twinning.
This paper describes a Qualitative/Screening Methodology included in the draft ANS Low Power and Shutdown (LPSD) PRA (Probabilistic Risk Assessment) Standard. The screening methodology can be used to eliminate certain specified shutdown POSs (Plant Operating States) from requiring further quantitative risk assessment in the context of a specified application based on demonstrating that their risk is lower than some predetermined limiting value. The paper also describes a methodology for qualitative risk assessment (QRA) tools that are used to support the screening process. The paper outlines the bases of both methodologies. (authors)
OBJECTIVEEvaluate the qualitative and quantitative differences between moderated and unmoderated on-line social support groups focused on asthma.DESIGNA...Full Text Available
Much progress has been made in understanding the complex pharmacokinetics of trichloroethylene (TCE). Qualitatively, it is clear that TCE is metabolized to multiple metabolites either locally or into...Full Text Available
OBJECTIVE AND DESIGNThis study used qualitative and quantitative methods to examine the reasons primary care physicians and nurses offered for their inability to initiate guideline-concordant...Full Text Available
Although the German Molasse Basin can be regarded as a mature hydrocarbon province, no regional sequence stratigraphic analysis has been carried out so far. We have studied seismic lines and well data from the region between the Isar and Inn rivers (SE Germany) that have been generously supplied by German oil companies (DEE, BEB, Mobil, RWE-DEA and Wintershall). Initial work indicates that five major seismic sequences within three main depositional cycles are developed. The Alpine thrust belt to the south serves as the primary sediment source in the foreland basin. However, sedimentary infill mainly took place parallel to the basin axis. Our analysis suggests that the stratigraphic development of the Molasse Basin was mainly controlled by eustatic sea-level changes which caused the shoreline to shift in the W-E direction. The shifting of the depocenter axis in a N-S direction was controlled by the tectonic evolution of the thrust belt. The ...
Lubricating Oil Analysis (LOA) has become an important part of a comprehensive Reliability Centered Maintenance (RCM) program. However, knowing the condition of the lubricant alone does not provide a complete description of equipment reliability. Condition monitoring for equipment can be accomplished through Wear Particle Analysis (WPA). This usually involves separating suspended materials and wear products from the lubricant by magnetic (ferrographic) means. This paper will present a simple, low-cost, alternate method of particle acquisition called Filter Patch Extraction (FPE). This method removes solids, regardless of their composition, from the lubricant by vacuum filtration and deposits them onto a filter for microscopic examination similar to that of analytical ferrography. A large filter pore size retains suspended materials and permits rapid filtration of large volumes of lubricant thereby increasing the accuracy of the wear and ...
Nuclear Forensics is a key element in the response process which is initiated after detection of illicit nuclear or other radioactive material. Credible nuclear forensics relies on appropriate sampling procedures, on validated analytical methods and on thorough data analysis and interpretation. Nuclear forensics aims at providing clues on the history and the potential origin of the material. Elemental and isotopic composition of the material, as well as its macroscopic and microscopic appearance reflect the technological processes used for the fabrication of the material. The nuclear forensic analysis first of all results in measurement data. Through appropriate processing of these data information on the nature and the history of the material can be obtained. A number of data evaluation techniques serving this purpose are conceivable and have been applied. On the one side, statistical methods like principal component ...
Qualitative interpretation of data of different nature and sources, based on segmentation techniques such as discriminant analysis, is useful to characterize and monitor hydrocarbon reservoirs. In order to make this interpretation more reliable, it is necessary to characterize uncertainties attached to data and then, to propagate them in the interpretation work-flow. In this thesis, uncertainties are represented by intervals, because usually, little is known about input data errors. The uncertainty characterization issue is dealt with specifically for each case study. The uncertainty propagation issue is treated by a new technique, based on interval analysis, which consists in extending to intervals various popular approaches (non parametric, quadratic and linear) to discriminant analysis: Firstly, a learning phase allows calibrating an imprecise classifying model on the basis of pre-interpreted data. ...
Porosity evolution at reactive interfaces is a key process that governs the evolution and performances of many engineered systems that have important applications in earth and environmental sciences. This is the case, for example, at the interface between cement structures and clays in deep geological nuclear waste disposals. Although in a different transport regime, similar questions arise for permeable reactive barriers used for biogeochemical remediation in surface environments. The COMEDIE project aims at investigating the coupling between transport, hydrodynamics and chemistry when significant variations of porosity occur. The present work focuses on a numerical benchmark used as a design exercise for the future COMEDIE-2D experiment. The use of reactive transport simulation tools like Hytec and Crunch provides predictions of the physico-chemical evolutions that are expected during the future experiments in laboratory. Focus is given in this paper on the ...
In the stereolithography process, three dimensional parts are built layer by layer using a laser to selectively cure slices of a photocurable resin, one on top of another. As the laser spot passes over the surface of the resin, the ensuing chemical reaction causes the resin to shrink and stiffen during solidification. When laser paths cross or when new layers are cured on top of existing layers, residual stresses are generated as the cure shrinkage of the freshly gelled resin is constrained by the adjoining previously-cured material. These internal stresses can cause curling in the compliant material. A capability for performing finite element analyses of the stereolithography process has been developed. Although no attempt has been made to incorporate all the physics of the process, a numerical platform suitable for such development has been established. A methodology and code architecture have been structured to allow finite elements to be birthed (activated) ...
The US Environmental Protection Agency (EPA) conducted a cost-effectiveness (CE) analysis to estimate the incremental cost of complying with the proposed effluent limitation guidelines (ELGs) for the coastal oil and gas industry (EPA 1995a). EPA`s CE analysis calculates the pounds of each pollutant that would be removed if the chosen discharge option is selected. In 1993, EPA issued final ELGs for the offshore oil and gas industry and published an offshore CE analysis. The chemical characteristics of produced water from the offshore region are essentially the same as those of produced water from the coastal region. It was surprising, therefore, that EPA chose a much longer list of pollutants and generally stricter weighting factors for the coastal CE analysis. This report reviews the data, assumptions, and analyses used in EPA`s coastal CE analysis and ...
Multiple linear regression, principal component analysis, partial least squares, polynomial regression and artificial neural networks are popular techniques for process modeling. An industrial case study illustrates some of these technologies, with an emphasis on artificial neural networks. Experience with this and other projects indicates that while neural network models, combined with partial least squares when necessary, are an excellent tool for modeling, linear techniques may also be appropriate in some cases. Regardless of the specific method used, software analyzers are an attractive lower-cost alterative to hardware options in some monitoring applications. From a fundamental point of view, the result of chemicalanalysis can be considered as the dependent variable(s) of a process system having a number of independent variables. The independent variables are the causes and the chemical ...
For analysis of a small quantity of americium, it is necessary to separate from curium which has similar chemical property. As a chemical separation method for americium and curium, the oxidation of americium with pentavalent bismuth and subsequent co-precipitation of trivalent curium with BIP O{sub 4} were applied to analyze americium in irradiated MOX fuels which contained about 30wt% plutonium and 0.9wt% {sup 241}Am before irradiation and were irradiated up to 26.2GWd/t in the experimental fast reactor Joyo. The purpose of this study is to measure isotopic ratio of americium and to evaluate the change of isotopic ratio with irradiation. Following results are obtained in this study. (1) The isotopic ratio of americium ({sup 241}Am, {sup 242m}Am and {sup 243}Am) can be analyzed in the MOX fuels by isolating americium. The isotopic ratio of {sup 242m}Am and {sup 243}Am increases up to 0.62at% and 0.82at% at maximum burnup, ...
Waste form dissolution studies and preliminary performance analyses were carried out to contribute a part of the data needed for the selection of a waste form for the disposal of Savannah River Plant defense waste in a deep geologic repository. The first portion of this work provides descriptions of the chemical interactions between the waste form and the geologic environment. We reviewed critically the dissolution/leaching data for borosilicate glass and SYNROC. Both chemical kinetic and thermodynamic models were developed to describe the dissolution process of these candidate waste forms so as to establish a fundamental basis for interpretation of experimental data and to provide directions for future experiments. The complementary second portion of this work is an assessment of the impacts of alternate waste forms upon the consequences of disposal in various proposed geological media. Employing systems analysis ...
This report is the 1992 annual progress report for the Energy Conversion and Storage Program, a part of the Energy and Environment Division of the Lawrence Berkeley Laboratory. Work described falls into three broad areas: electrochemistry; chemical applications; and materials applications. The Energy Conversion and Storage Program applies principles of chemistry and materials science to solve problems in several areas: (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes and chemical species, and (5) study and application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, ...
The non-isothermal pyrolysis kinetics of Acetocell (the organosolv) and Lignoboost (kraft) lignins, in an inert atmosphere, have been studied by thermogravimetric analysis. Using isoconversional analysis, it was concluded that the apparent activation energy for all lignins strongly depends on conversion, showing that the pyrolysis of lignins is not a single chemical process. It was identified that the pyrolysis process of Acetocell and Lignoboost lignin takes place over three reaction steps, which was confirmed by appearance of the corresponding isokinetic relationships (IKR). It was found that major pyrolysis stage of both lignins is characterized by stilbene pyrolysis reactions, which were subsequently followed by decomposition reactions of products derived from the stilbene pyrolytic pr...
Techniques of chemicalanalysis, amino acid sequencing and autoradiography are being used to study the frequency of incorporation of normally noncoded amino acids into hemoglobins and seminal fluid proteins. We are studying, by the sequencing of radiolabeled proteins followed by the recovery of ["3H] isoleucine phenylthiohydantoin by high-performance liquid chromatography, the frequency at which normally noncoded isoleucine is incorporated into hemoglobin because of base-substitution mutations versus translational errors. Irradiation increases the isoleucine content of human hemoglobin and the frequency of substitution of isoleucine for specific amino acids in rabbit hemoglobin. Studies to date indicate that these techniques have been developed sufficiently for initial analysis of the potential of drugs and environmental pollutants to induce base-substitution mutations in mammalian somatic cells.
The development of the monitoring network for background measurements of air pollution in the USSR is noted. The use of paired stations, to aid in locating permanent sites as well as for determining the local component of background air pollution, is described. Thermoelectric actionometers with five glass filters are used to measure Shupp's turbidity coefficient for estimating extinction of solar radiation due to aerosols. Sampling and chemicalanalysis of precipitation uses methods developed during the International Geophysical Year. An intercomparison of meteorological instruments was carried out in the USSR in 1973 and 1978. The most stable actinometer was the Linke-Foisner device. Chemical analyses of precipitation made since 1958 in the USSR show increases in air pollution levels only in particular areas.
The effect of chemical pretreatments using NaOH, H2O2, and Ca(OH)2 on Empty Palm Fruit Bunches (EPFB) to degrade EPFB lignin before pyrolyis was investigated. Spectrophotometer analysis proved consecutive addition of NaOH and H2O2 decomposed almost 100% of EPFB lignin compared to 44% for the Ca(OH)2, H2O2 system while NaOH and Ca(OH)2 used exclusively could not alter lignin much. Next, the pretreated EPFB was catalytically pyrolyzed. Experimental results indicated the phenolic yields over Al-MCM-41 and HZSM-5 catalysts were 90wt% and 80wt%, respectively compared to 67wt% yield for the untreated sample under the same set of conditions. Meanwhile, the experiments with HY zeolite yielded 70wt% phenols.
In order to investigate the antioxidant properties of the polysaccharides from the brown alga Sargassum fusiforme, the crude polysaccharides from S. fusiforme (SFPS) were extracted in hot water, and the lipid peroxidation inhibition assay exhibited that SFPS possessed a potential antioxidant activity. Hence, two purely polymeric fractions, SFPS-1 and SFPS-2 were isolated by the column of DEAE (2-diethylaminoethanol)-Sepharose Fast Flow, with their molecular weights of 51.4 and 30.3 kDa determined by high performance gel permeation chromatography (HPGPC). They were preliminarily characterized using chemicalanalysis in combination of infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and found to contain large amounts of uronic acids and ?-glycosidical linkages. The antioxida...
The 1993 Petroleum Hydrocarbons Conference was comprised of 3 days of technical presentations within the following topic areas: pollution prevention and cost control; development of remediation levels; free-phase and dissolved hydrocarbon contamination management; investigation and analysis of petroleum hydrocarbons; applications of computer modeling for remediation; design and implementation of bioventing; design and implementation of air sparging; soil vapor extraction as a remediation technique; and ground water remediation using natural bacteria. In addition, more than 100 leading companies in the ground water and petroleum industries participated in the Conference Exposition in which a variety of equipment and services for preventing, detecting and remediating ground water contaminated by petroleum hydrocarbons and other organic chemicals was showcased. Individual papers have been processed separately for inclusion in the appropriate data ...
The authors examine the overheating of a chemical detonation wave, which results in hybrid detonation processes, for example, photochemical or electrochemical detonation, depending on the source. The schemes for obtaining the overheated detonation are shown. Analysis has shown that: normal stationary overheated detonation waves are possible when the overheating power density is constant, just as when the specific energy of overheating is constant; the use of the ''gas'' equation of state for describing overheated detonation in condensed explosives yields wave parameters which are too high; and the assumption that the chemical energy released in the explosive is independent of the overheating energy also leads to wave parameters which are too high, and the overestimation increases as the overheating is intensified.
An analysis is presented for the effects of chemical reaction and thermal radiation on hydromagnetic free convection heat and mass transfer for a micropolar fluid via a porous medium bounded by a semi-infinite vertical porous plate in the presence of heat generation. The plate moves with a constant velocity in the longitudinal direction and the free stream velocity follows an exponentially small perturbation law. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micropolar fluid with a suction velocity varying with time. Analytical expressions are computed numerically. Numerical calculations are carried out the purpose of the discussion of the results which are shown on graphs and the effects of the various dimensionless parameters entering into the p...
The use of dendrimers for preparing chemically sensitive interfaces for detecting volatile organic compounds (VOCs) using surface acoustic wave (SAW) device transducers is described. Specifically, the synthesis of the dendrimers and the means by which they are affixed to SAW devices is discussed, followed by a detailed spectroscopic analysis of the surface-confined dendrimers and a discussion of their interaction with different VOCs. Most of these preliminary experiments focus on dendrimer surface modification using benzoylchloride, which leads to phenyl terminal groups linked to the dendrimer via amide groups. The results of this study lead us to conclude that dendrimers: (1) provide general specificity towards classes of functional groups and are therefore suitable for array-based sensing schemes; (2) are intermediate in structure between monolayers and polymers and exhibit the desirable properties of both; (3) can be straightforwardly ...
The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.
The chemical composition and the semiconducting properties of passive films formed on nickel based alloy (Alloy 600) in acidic sulphate solution, pH 2.0 at room temperature were studied using Auger analysis, voltammetric techniques and the Mott-Schottky approach. The results obtained revealed that the presence of both chromium and mixed nickel-iron oxides in the films leads to the development of a p-n heterojunction, which controls their electronic structure, similarly manner to the case of stainless steels and Alloy 600 in borate buffer solution. This behavior has been interpreted as representing of an oxide system, which has a duplex character, with an inner p-type semiconducting region, mainly formed by chromium oxide and an outer n-type semiconducting region, containing iron oxide. It could also be observed that the nickel oxide present in the films acts as a barrier layer conferring improved protection.
UO/sub 2/(OH)xReO/sub 4/xH/sub 2/O, UO/sub 2/(OH)ReO/sub 4/x0.5H/sub 2/O and UO/sub 2/(OH)ReO/sub 4/ were produced and their physical and chemical properties were studied for the first time. The chemicalanalysis was carried out and pycnometric density of the initial crystallohydrate and basic uranyl anhydrous perrhelate wos determined. The two-step mechanism of the dehydration of uranyl hydroxoperrhenate monohydrate was revealed. Values of interplane distances were calculated for a number of roentgenogram lines of the basic uranyl perrhenate and its crystallohydrates. IR spectra of all revealed compounds in the region of 4000-250 cm/sup -1/ were studied.
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Analyses of process system properties were continued for important chemical materials involved in the several processes under consideration for semiconductor and solar cell grade silicon production. Major activities were devoted to physical, thermodynamic and transport property data for silicon. Property data are reported for vapor pressure heat of vaporization, heat of sublimation, liquid heat capacity and solid heat capacity as a function of temperature to permit rapid usage in engineering. Chemical engineering analysis of the HSC process (Hemlock Semiconductor Corporation) for production of silicon was initiated. The process is based on hydrogen reduction of dichlorosilane (DCS) to produce the polysilicon. The chemical vapor deposition reaction for DCS is faster in rate than the conventional process route which utilizes trichlorosilane (TCS) as the silicon raw material. Status and progress are ...
The dynamic response of thin liquid storage tanks to earthquakes is a very complicated phenomenon, because it can be highly non linear. Among others, one can meet material and geometric non linearities of the tank shell leading eventually to static or dynamic buckling non linear behavior of anchor bolts, contact non-linearities due to the uplift of the tank base and to the unilateral character of the fluid pressure on the shell and high amplitude fluid oscillations. Moreover, linear or non linear soil structure interaction affects considerably the response of the fluid structure system under consideration. In this paper we focus attention on problems related only to the base uplift and anchors plastification. We study a tank similar to the Hualien project tank, but we neglect the soil structure interaction. The studied tank is representative of medium height to radius ratio ratio tanks with relatively thick bottom plate. The contact is simulated via a simple discrete penalty method in ...
We review the current status of Andreev reflection spectroscopy on the heavy fermions, mostly focusing on the case of CeCoIn5, a heavy-fermion superconductor with a critical temperature of 2.3 K. This is a well-established technique to investigate superconducting order parameters via measurements of the differential conductance from nanoscale metallic junctions. Andreev reflection is clearly observed in CeCoIn5 as in other heavy-fermion superconductors. Considering the large mismatch in Fermi velocities, this observation seemingly appears to disagree with the Blonder-Tinkham-Klapwijk (BTK) theory. The measured Andreev signal is highly reduced to the order of maximum ?13% compared to the theoretically predicted value (100%). The background conductance exhibits a systematic evolution in its asymmetry over a wide temperature range from above the heavy-fermion coherence temperature down to well below the superconducting transition temperature. Analysis of the ...
Nova Corporation and its related businesses are involved in natural gas production, gas pipelines, consulting services, and upgrading of natural gas into chemicals and plastics. Nova owns Alberta Gas Transmission Division, the primary gas transportation system in Alberta, with 11,400 miles of pipeline and total deliveries in 1992 of 3.4 trillion ft"3. Nova also owns 50% of Foothills Pipe Lines Ltd., one of Canada's largest carriers of exported gas, and 50% of TQM Pipeline Partnership, which transports natural gas in Quebec. Nova conducts its chemicals business through Novacor Chemicals Ltd., which has plants in Alberta, Ontario, Quebec, and the USA. Novacor's major petrochemicals are methanol, ethylene, propylene, and styrene and its major plastics are polystyrene, polypropylene, and polyethylene. Nova's gas-producing branch Novalta Resources produced 26 billion ft"3 of natural gas in 1992 and has proven reserves of 334 ...
In this study, two different humic acids extracted from England and China peat soil, as well as three purified products extracted from commercially available humic acids [Fluka (Fluka, Neu-Ulm, Germany, Alfa (Alfa Aesar, Ward Hill, USA) and Aldrich (Aldrich-Chemical Co, Gillingham-Dorset)] were obtained respectively with the modified IHSS (International humic substances society) procedure. The chemical and structural information of these humic acids were characterized by some techniques, such as elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and electropotential titration. UV-Vis spectra, infrared spectra, values for elemental composition and the contents of carboxyls, phenolic hydroxyls and total acidities of these humic acids were acquired. It is indicated that all these humic acids are different in the aspect of chemical structure, ...
Newly commercialized Fourier transform Raman spectroscopic instrumentation provides a simpler alternative for vibrational spectroscopic analysis. Instrument vendors currently design for laboratory use, but there are many potential process applications of these stable, easy to use instruments. Raman spectroscopy is highly suited to analysis of aqueous samples. Near infrared excitation minimized fluorescence interference and allows for remote operation via fiber optic probes. The Department of Energy has funded research at the Measurement and Control Center to establish the utility of this method for on-line composition analysis in distillation columns. Laboratory evaluation and instrument employs an air-cooled laser and a thermoelectrically cooled detector. The device is mounted on a three by foot cart for convenient location in control rooms. Current fiber optic extension cables allow for analysis in a ...
Full text.Sediments are the ultimate sink of trace elements. The total metal analysis may only give information concerning possible enrichment of metals. The analysis of metal partitioning in the different chemical components of sediments (exchangeable, carbonate, easily reducible, moderately reducible, organic and residual); give a detailed information on the way in which these metals are bound to sediments, their mobilization capacity and their ability to affect water quality under different environmental conditions. The studied river basin is dominated by limestone formation, the enrichment of metals in the carbonate sediment fraction is a high probability. The objective of the study was to determine the percentage of the total metal content (Fe, Mn, Zn, Cu and Pb) in the six chemical fractions of the bed load sediments of Nahr-Ibrahim river during the dry season and verify the role of carbonate for ...
Radionuclide X-ray fluorescence analysis is a method, which has many advantages for analysing various historic artefacts, as it is relatively cheap, sensitive and non-destructive, and it allows measurements in-situ. However, this analysis has also certain limitations especially concerning sensitivity to chemical elements only, irrespective of the compounds or chemical forms in which these elements have been bonded. In addition, light elements emitting very soft X-rays cannot be measured, and in order to detect a wide range of elements, it is necessary to carry out repeated measurements with different radiation sources. Despite these limitations, valuable information can be obtained about the composition of historic materials and data about the origin and age of these artefacts can be derived. Analyses of wall paintings, ancient metal sculptures or other objects of art provide the basis for historic ...
Radionuclide X-ray fluorescence analysis is a method, which has many advantages for analysing various historic artefacts, as it is relatively cheap, sensitive and non-destructive, and it allows measurements in-situ. However, this analysis has also certain limitations especially concerning sensitivity to chemical elements only, irrespective of the compounds or chemical forms in which these elements have been bonded. In addition, light elements emitting very soft X-rays cannot be measured, and in order to detect a wide range of elements, it is necessary to carry out repeated measurements with different radiation sources. Despite these limitations, valuable information can be obtained about the composition of historic materials and data about the origin and age of these artefacts can be derived. Analyses of wall paintings, ancient metal sculptures or other objects of art provide the basis for historic ...
There is no possibility to check any inner part at real welded joint at nuclear power station (NPS) during operation because any destructive test cannot be used. In practice there is checked surface of weld. There are used four methodical instructions for the check of real welds: 1. The visual inspection, 2. The measurement of hardness, 3. The chemical composition checking and 4. The microstructure replica analysis. It is necessary to know how these information of weld surface are in accordance with characteristics of inner parts of weld. If there is not any difference between surface weld microstructure and internal weld microstructure of experimental weld it is supposed to that there is not any difference in other measured properties of welds. If is changed structural characteristics of microstructure, it is changed also hardness, chemicalanalysis etc. It was observed that the microstructure of real ...
Very High Temperature gas cooled nuclear Reactor (VHTR), which was coupled with Sulfur-Iodine (SI) thermo-chemical cycle, has been selected for the Nuclear Hydrogen Development and Demonstration (NHDD) project in Korea Atomic Energy Research Institute. Among the various hydrogen production methods, Sulfur-Iodine (SI) thermo-chemical cycle is a good method as a massive hydrogen production without CO2 emission. In SI cycle, the sulfuric acid decomposition is one issue for the material corrosion on high temperature and pressure condition. For the simulation of the sulfuric acid decomposition, we designed a sulfuric acid loop with a small-scale gas loop which is simulated for the integrity and feasibility tests on a H2SO4 decomposition process. The primary objective of the loop is to validate the corrosion and the mechanical performances of a key component of the NHDD, Process Heat Exchanger (PHE). In this paper, we discussed the preliminary ...
A method for quick, high-accuracy measurement of lithium isotopes has become necessary in carrying out research on the separation and concentration of lithium isotopes by ion exchange. The present report focuses on the application of a hollow cathode, as excitation source, to emission spectral analysis for lithium isotope measurement. The grating monochromator used incorporates a pressure scanned etalon. With decreased Doppler broadening and pressure broadening, the hollow cathode, used as excitation source, can give narrow spectral lines, permitting good separation among them. To achieve a high accuracy, the emission intensity of the hollow cathode should be maintained as stable as possible relative to time. In particular, the stability of a light source can be affected significantly by the chemical form of the sample. A study is also made here to identify a condition where lithium acetate effluent as-obtained from an ion exchange column can ...
The buckwheat soup is a mixture of seasonings such as soy sauce, sweet sake, sugar and the like and stock of dried bonito. This paper describes an analysis of the stock manufacturing step, an important step in the manufacture of buckwheat soup, and the setting of stock extraction conditions on the basis of this analysis. If the rate of infiltration of water into the dried bonito is found, it is a very effective finding for setting the thickness of flakes of dried bonito and the extraction time to prepare buckwheat soup industrially. To obtain such knowledge, the time taken for the water to pass through flakes of dried bonito of various thicknesses, to vaporize and to remove latent heat till the temperature of the surfaces of flakes lowers was measured. The thickness of flakes of dried bonito and extraction time were set on the basis of the data thus obtained. Dired bonito was then supplied to a bench scale flow extraction apparatus filled with ...
An analysis was made on corrosion suppression mechanism of glycoletherdiaminetetraacetic acid (GEDTA) film made from GEDTA on stainless steel, and its corrosion inhibition effect. Results of analysis using IR spectrum, IR-ATR spectrum, {sup 1} HNMR spectrum, and ESCA spectrum indicated the deposition of the GEDTA film is a chemical deposition. In polarization tests at pH = 5 and 7, both polarization curves shifted to the constant current density side, showing suppression effect in reactions at both pH. When the corrosion environment is made severer, such as to pH = 2 and 4, the corrosion suppression effect of GEDTA became more distinctive. A ferroxyl test identified very little difference between untreated and treated materials. In a chemical pitting test, because oxidant and corrosive anion coexist in the test solution, and GEDTA is stable against corrosive anion Cl {sup {minus}}, the film is unstable ...
Devolatilization, char combustion and emission characteristics of different single fuel particles were studied under various fluidized bed combustor conditions, in order to develop a classification system which enables prediction of the behaviour of different fuels ranging from fixed carbon rich coals to volatile rich woods and plastics. To investigate formation reaction, the concentration of CO, CO{sub 2}, total hydrocarbons, O{sub 2}, NO and N{sub 2}O were measured continuously. Additionally, temperature histories of the particles were recorded by implanting thermocouples. Devolatilization and char combustion were analysed by an integral and differential method. The integral analysis uses global rates which were compared with the ultimate and proximate analyses and used to classify the fuels. In the differential analysis the single physical and chemical steps viz mass transfer from the bulk gas to the particle surface, ...
A case study is presented where an integrated, ecologically relevant exposure assessment is presented for a polluted lowland river. Using partial least squares regression of latent structures (PLS), an analysis of the impact of two effluents on physico-chemical water quality measures, macroinvertebrate and diatom communities, and in situ bioassay responses with four different test species are combined into an integrative exposure assessment. Bioassays focussed on growth and condition related endpoints, because they are key functional processes of organisms and populations. Integrating these multiple lines of evidence, we were able to discriminate among the impact of both effluents, link changes in physico-chemical water quality with bioassay endpoints and ecological quality of the ecosystem, and address the importance of integrating all information into one exposure assessment framework. The bioassays under field conditions ...
The thermal properties of five types of radiation-induced wood-polymer composites based on a tropical hardwood, rubberwood (Hevea braziliensis), was studied by oxygen index measurement, differential thermal analysis (DTA) and thermogravimetry (TG). The DTA and TG curves of composites were different from those of rubberwood, which can be attributed to the presence of the incorporated polymers. Of the five composites, the one impregnated with bis(2-chloroethyl)vinyl phosphonate reduced the initial temperature of decomposition, increased the peak temperatures of exothermic reactions, and increased the char yield. Comparison with physical blends of rubberwood and the corresponding polymer provided some evidence of chemical interaction of wood and polymer in some of the composites. (author).
The ore-hosting Yaojia Formation is composed of a set of braided stream medium-fine grained sediments. Guided by the basic theory of high-resolution sequence stratigraphy, and based on the core observation, the analysis of chemical composition of rocks, and data of natural potential logging and apparent resistivity logging, the authors have set up the high-resolution sequence stratigraphy framework of the ore-hosting Yaojia Formation, and discussed the relation of the stratigraphic structure of the middle cycle, as well as the paleotopography, the micro-facies to the formation of uranium deposit. (authors)
Chemical and phase homogeneity of titanium-niobium sponge, produced by a combined magnesium-thermic reduction of niobium pentachloride and titanium tetrachloride mixtures, is investigated. It is ascertained that a sponge consists of spherical shape particles and has a large number of pores. Particle sizes are reduced with niobium being substituted for titanium from 50-500 #mu#m for titanium sponge to 1-40 #mu#m for niobium one, which testifies to the bormation in a titanium-niobium sponge of an alloy and not a mechanical mixture. A number of solid solutions is detected by X-ray phase analysis. Lattice parameters are determined.
The chemical properties of alloys in a given environment are to a large extent governed by the surface composition. Changes of the surface composition during passivation are important features in this respect. Previous studies of single crystal Ni-Mo alloys surfaces have been reported. The aim of this work was to obtain quantitative data, for the natural oxide and the passive films formed on Ni-6% Mo(100) and (110) alloys, using Rutherford backscattering spectroscopy and nuclear reaction analysis.
The chemical properties of alloys in a given environment are to a large extent governed by the surface composition. Changes of the surface composition during passivation are important features in this respect. Previous studies of single crystal Ni-Mo alloys surfaces have been reported. The aim of this work was to obtain quantitative data, for the natural oxide and the passive films formed on Ni-6% Mo(100) and (110) alloys, using Rutherford backscattering spectroscopy and nuclear reaction analysis. (author).
The activities of the radiochemical section (part of the Analytical Chemistry Group) deal mostly with problems of composition. Activation analysis with thermal neutrons serves for most of the trace element analyses either with or without chemical separations. Ge(Li) spectrometry has been increasingly automated so that many analyses can now be performed by relatively unskilled personnel. In a number of analyses an A.V.F.-cyclotron was employed: such an accelerator can deliver not only different types of charged particles at variable energies but also fast neutrons. (T.G.).
The study of imported ceramics found in Beirut and suspected to belong to north Syrian products will provide key evidence for the roles in trade of the various postulated centers in northern Syria and northern Lebanon. It is proposed that a comprehensive range of likely north Syrian products imported to Beirut will be chemically analyzed by PIXE (proton induced X-ray emission) in order to characterize, compare and isolate the various regional production centers that supplied the city from the Persian to Byzantine periods. In this work, we were mainly focusing on the characterization of Amrit products, by using 3 MeV proton beam and Al funny filter, as X-ray absorber.
This paper presents the results of a series of experiments performed to study the effect of initial pressure vessel conditions on the extent of melt dispersal from scaled reactor cavities and describes progress in development of a mathematical model which is designed to predict the melt mass dispersed from reactor cavities as a function of reactor vessel initial conditions and on the vessel breach area. The model, which is being developed to also characterize the heat transfer and chemical reaction phenomena which would take place within the reactor cavity, is designed to be incorporated into a lumped-parameter containment analysis computer code.
Morocco is among the world's leading countries in terms of total indigenous oil shale resources. Following the 1973 oil crisis, Morocco has been determined to develop its oil shale energy resources. In the subsequent years following the crisis, a tremendous number and variety of studies and research efforts have resulted in an enormous amount of data, covering geological, hydrogeological, mining, physical and chemical aspects of the two main deposits, Timahdit and Tarfaya. This article represents a tentative analysis of oil shale development in Morocco and offers a few ideas on where it might be heading. 1 fig., 2 photos.
Severe pitting corrosion occurred in a horizontal steel pipeline used to transport multiphase fluid, including water, oil, and natural gas, after 2 months of service. The pitting corrosion rate was up to 42 mm/year. Chemicalanalysis, X-ray diffractometry, and EDAX showed that the corrosion products mainly consisted of Fe9S8, FeCO3, and NaCl. Calcium containing inclusions were also found in the matrix of the steel, which may accelerate corrosion. The early failure was attributed to the high proportion of water, the slow flow velocity, and the use of unqualified material. (Author)
The author presents a mathematical model for analysis of the impact of scrubber bed length, porosity, and gas flow rate on the absorption of CO{sub 2} in a breathing apparatus. The model accounts for the decrease in available absorbent through chemical conversion. The predicted efflux of CO{sub 2} from a canister containing LiOH compared favorably with measured values reported elsewhere. It was determined from a computational study that the time for breakthrough of CO{sub 2} at a prescribed level is nearly directly proportional to bed length and inversely proportional to gas flow and porosity.
An experiment has been performed to investigate the chemical reaction between the liquid phases of the eutectic lithium-lead (Li/sub 17/Pb/sub 83/) and water. The reactants and products were constrained within a closed reaction vessel, allowing the extent of reaction to be determined from the partial pressure of the hydrogen reaction product. The data from the tests showed that the extent of reaction did not depend upon the water temperature. The data also indicated that the extent of reaction passed through a maximum as the initial liquid metal temperature was varied from 350 to 500 C, and a model was developed to explain this behavior. 11 refs., 3 figs.
Cement-based composites are widely used in applications which demand long-term service life. One important example is in immobilization matrices for low-level radioactive and other hazardous wastes, which demands long-term retention and durability. The authors describe conductivity measurements of grouts flooded with water and in contact with a sink that consists of pure water. The conductivity measurements were designed and carried out in parallel with present quality verification methods and standard leach tests of the nuclear waste management industry. For the first time, the authors show that the method of replacing intrusive chemicalanalysis with conductivity measurements of the leaching samples yields equivalent results.
A chromium-free conversion coating for magnesium alloys were described. The conversion coating could be obtained when AZ31D magnesium alloy was immersed in a solution containing a manganese salt, phosphate and an inhibitor. Corrosion resistance of the chemical conversion coating was evaluated by anodizing polarization curve and salt immersion. XRD analysis showed that the conversion coating was mainly composed of Mn{sub 3}(PO{sub 4}){sub 2}. The morphology of the coating is observed by using SEM. The effect of electrolyte pH and concentration of inhibitor on coating growth are investigated. (orig.)
This paper explores the potential of combining substance-flow modelling with water and wastewater sampling to trace consumption-related substances emitted through the urban wastewater. The method is exemplified on sucralose. Sucralose is a chemical sweetener that is 600 times sweeter than sucrose and has been on the European market since 2004. As a food additive, sucralose has recently increased in usage in a number of foods, such as soft drinks, dairy products, candy and several dietary products. In a field campaign, sucralose concentrations were measured in the inflow and outflow of the local wastewater treatment plant in Linkoping, Sweden, as well as upstream and downstream of the receiving stream and in Lake Roxen. This allows the loads emitted from the city to be estimated. A method c...
This paper first introduces the calculating method of radium specific activity to determine the radon emanation rate of tailing of uranium mine No. 794, the method needs two parameters: radon emanation coefficient and radon diffusion coefficient. According to the measured results of parameters and the contrast between radium specific activity of indoor chemicalanalysis of field sample and field gamma-ray spectra, the authors discuss the variation rules and characteristics of radon emanation coefficient and radon diffusion coefficient, and the best climate and seasons for measuring these parameters in northern China, and finally summarize the characteristics of this method through analyzing measured results. (authors)
The main points of quality control methods and technique of environmental radiological baseline study of Guangdong Daya Bay Nuclear Power Station are reported. Results of intercalibration of international and inland laboratories are given. The random chosen samples are checked and compared with two measurement methods. The data obtained in Daya Bay environment are put to the correlation statistics test using the linear regression analysis method between the correlative items such as "4"0K activity by gamma spectrum measurement and potassium content by chemicalanalysis, total #alpha#(#beta#) activity and nuclide content, as well as environmental gamma radiation dose rate and TLD accumulation dose. The data of Daya Bay environmental radioactivity baseline level show good concordance and reliability.
Improved radionuclide generator include a substantially insoluble salt of a radioactive parent which may be directly packed in column for subsequent elution of the daughter radionuclide. An improved 188Re generator was prepared by reacting a radioactive tungsten (188W) as parent radionuclide incorporated with aluminum chloride to obtain an insoluble radioactive aluminum tungstate matrix. The investigated matrix was characterized on the basis of the chemical composition, IR, thermal analysis and mechanical stabilities. The factors affecting the elution performance were studied such as influence of pH, molar ratio and drying temperature. From the obtained data, the molar ratio W:Al was 1.5:1 at pH?=?4, the matrix dried at 105??C for 2 h. Chromatographic and multichannel analysis has been cur...
Background, aim, and scope Soil as a landscape body contains wide ranges of physical, chemical, morphological, and mineralogical properties, both laterally and vertically. Soils with similar properties and environments are expected to behave similarly. A statement on land use potential will depend in part on the precision and accuracy of the statements that can be made about the soils. This information has some practical applications in optimizing land management and productivity improvement. The spatial patterns and dependence of some selected physicochemical properties of brackish marsh and surrounding soils were investigated using a 2-D kriging analysis in conjunction with a geostatistical (GS+, Michigan) model. Materials and methods Composite (four subsamples) surface samples (0?20?cm)...
A detailed discussion of airborne CO{sub 2}, DIAL measurements obtained from the first joint N-ABLE field campaign at INEL is presented. System performance characteristics, including return signal strength, averaging statistics, and temporal correlation as well as multi-line DIAL spectral data are discussed. In particular, we review data acquisition and analysis strategies pertinent to chemical detection from a moving platform, such as range determination and correction, and return signal processing (waveform vs. box-car integration, baseline correction). We also report observed effects and variations due to near-field light scattering, pointing and tracking stability, and stack-release plume dynamics.
Fragranced consumer products are pervasive in society. Relatively little is known about the composition of these products, due to lack of prior study, complexity of formulations, and limitations and protections on ingredient disclosure in the U.S. We investigated volatile organic compounds (VOCs) emitted from 25 common fragranced consumer products-laundry products, personal care products, cleaning supplies, and air fresheners-using headspace analysis with gas chromatography/mass spectrometry (GC/MS). Our analysis found 133 different VOCs emitted from the 25 products, with an average of 17 VOCs per product. Of these 133 VOCs, 24 are classified as toxic or hazardous under U.S. federal laws, and each product emitted at least one of these compounds. For ''green'' products, emissions of these c...
In order to develop the filler metal for Hastelloy alloy XR structure with thick wall, the weldability and high temperature strength properties of Hastelloy alloy XR weldment were investigated using the filler metals, which were alloy-designed on the basis of multiple regression analysis. The former was examined through the chemicalanalysis in the deposited metal, bend test, FISCO cracking test, optical microscopy and hardness measurement. The latter was investigated by means of tensile and creep test. It was found from these results that the crack susceptibility in the weldment was apparent to be lowered without degrading the high temperature strength properties. Therefore, it is concluded that these filler metals possess excellent performance as the filler metal for Hastelloy alloy XR structure with thick wall. (author).
In order to quantify the biomass burning emissions, the main atmospheric pollution source of tropical and subtropical regions, we carried out the analysis of ashes that are also formed during these fires. To this end, we developed analytical methods to characterize the composition of savannah grass burning ashes by using X-ray fluorescence for mineral elements and microanalysis for C, H, O and N. Samples used in this work have been collected during laboratory combustion experiments, with chemically well-defined natural savannah grasses from Ivory Coasts and South Africa. The reproducibility and efficiency of different developed procedures have been studies. The analytical relative precision is generally better than 5%. This development has allowed to establish, for the first time, the global mass balance of ashes resulting from savannah grass burning. (authors). 16 refs., 3 figs., 8 tabs.
A series of cyclic voltammetry, chronoamperometry and electrochemical impedance experiments have been carried out in order to investigate the effect of cathode composition and porosity on the electrochemical characteristics of strontium-doped lanthanum, praseodymium and gadolinium cobaltite cathodes. The impedance responses at different electrode potentials of the half cell and symmetric single cell setups are compared and analyzed by the equivalent circuit modeling method. The deconvolution of impedance spectra for single cell cathode and anode reactions contributions based on the results of simultaneous analysis of half cells and symmetric single cells has been made by differential impedance real part vs. ac frequency plot analysis method. Noticeable influence of cathode chemical composition, meso-porosity and macro-porosity on the electrochemical activity of the oxygen electroreduction has been demonstrated. Seeming ...
A conformational analysis of ethyl azidoformate (EAF) has been carried out by the MINDO/3 quantum-chemical method. It has been shown that EAF exists in the form of two conformers differing with respect to rotation around the C-N bond. Complete optimization of the geometry has been carried out for both conformers. It has been found that the transoid conformation is planar and that the cisoid conformation is nonplanar. The height of the rotation barrier is 15.4 kcal/mole. The optimal geometry of the transition state has been calculated. It has been noted that a significant role in the mechanism of the conformational transition is played by the inversion of a nitrogen, which facilitates the transition. The results of the calculation have been confirmed by IR-spectroscopic data.
Acid mine drainage is probably the most important problem facing the mining industry. In this study, the authors evaluated different techniques for the remediation of mine tailings. An in situ characterization of the Aldermac mine tailings was conducted and the results were presented in this poster presentation. The site characterization was performed to determine the extent of the contamination, and sampling of soils was also performed for laboratory experiments in soil covers. The authors described the methodology followed in the laboratory experiments. Chemicalanalysis of the leaching water was performed to determine its composition in metals. Microbiological analysis was also conducted, as well as the determination of the water saturation index. The authors indicated that they will analyze the results further. tabs., 12 figs.
Banana bunchy top virus (BBTV), family Nanaviridae, genus Babuvirus, is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana plants. It is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific region. In this study we isolated, cloned and sequenced a BBTV sample from Hainan Island, China. The results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences motifs. We also predicted the physical and chemical properties, structure, signal peptide, phosphorylation, secondary structure, tertiary structure and functional domains of its encoding protein, and compare them with the corresponding quantities in the replication initiatio...
This paperwork explain the method of water sampling to obtain the precipitate of BaCO3 solutions that will be used to analyze 13C from field work in Kelana Jaya, Selangor, Langkawi, Kedah and Taiping, Perak. The sampling involves collecting of water samples for groundwater from boreholes and surface water from canal, river, pond and ex-mining pond from several locations at the study sites. This study also elaborates the instruments and chemicals used. The main purpose of this sampling is to obtain the precipitate of BaCO3 for 13C analysis of dissolved inorganic carbon (DIC). A correct sampling method according to standard is very important to ensure an accurate and precise result. With this, the data from the laboratory analysis result can be fully utilized to make the interpretation of the pollutants movement. (Author)
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at ...
In this study nanocrystalline powders of yttria-stabilized zirconia (ZrO_2-8Y_2O_3) have been synthesized through 'polymerized complex method'. Zirconium chloride, yttrium nitrate, citric acid and ethylene glycol were polymerized at 80 "oC to produce a gel-like mass in which metallic ions were uniformly distributed. During the thermal treatment of dried gel, nanocrystalline powder was formed at 450 "oC and 650 "oC for 2 h. Thermal reactions and crystalline phase formation of the dried gel were investigated through thermal analysis and X-ray diffraction analysis, respectively. The results of thermal analysis and XRD showed the formation of nanocrystalline powder at less than 600 "oC. Chemical bonding of the dried gel was investigated by Fourier transform infrared spectroscopy analysis. Morphology of powder calcined at 650 "oC was analyzed by scanning electron microscope. ...
For the interests of national security, many scientists who work in the field of nuclear forensic analysis have carried out extensive work in the past on the detection of radioactive material and attributions study, developed a series of scientific and technical means to trace and detect illicit circulation of nuclear materials used to weapons and other radioactive materials which impair public security. All these questions relate to physical, chemical, biological attribution of materials. The nuclear forensic analysis has already become a special, up-to-date sphere of learning. The goal of the study of nuclear forensics is to prevent terrorists from acquiring not only nuclear weapons but also mate- rials that can be used to make such weapons, including radioactive materials for nuclear power plants, and medical radioisotope to and provide us as many clues of environmental links as possible that could help us trace the ...
Systematic analysis of the energy level schemes, ground state absorption (GSA) and covalency effects for the Ni"2"+ ion in Ca_3Sc_2Ge_3O_1_2 was performed. The recently developed first-principles approach to the analysis of the absorption spectra of impurity ions in crystals based on the discrete variational multi-electron method (DV-ME) [K. Ogasawara et al., Phys. Rev. B 64, 115413 (2001)] was used in the calculations. As a result, complete energy level schemes of Ni"2"+ and its absorption spectra at both possible crystallographic positions (distorted octahedral Sc"3"+ and tetrahedral Ge"4"+ positions) were calculated, assigned and compared with experimental data. Energies of the charge transfer (CT) transitions for both positions are estimated. Numerical contributions of all possible electron configurations into the calculated energy states were determined. By performing analysis of the molecular orbitals (MO) population, ...
The passive films formed on iron metal, alloys or stainless steel are extremely thin oxides or hydroxides and possess the properties of high chemical stability in the environment. These films show characteristics interested both electrical as well as electrochemical point of view due to the thin thickness of the films. Auger Electron Spectroscopy, X-ray Photoelectron spectroscopy and so on which are the conventional electrochemical measurement methods or the surface analysis methods are used for the analysis and evaluation of these films, however, at present, the application of research technique focusing the superconductor characteristics of the films are tried. Although, the potential modulation reflection spectroscopy method has merits like possibility of in-situ measurement, high precision, possibility of stable analysis even for extremely thin film and so forth, it has also demerits like difficulty ...
Smoking during pregnancy is widely known to increase health risks to the foetus, and understanding the quitting process during pregnancy is essential in order to realise national government targets. Qualitative studies have been used in order to gain a greater understanding of the quitting process and the objective of this systematic review was to examine and evaluate qualitative studies that have investigated the psychological and social factors around women attempting to quit smoking during pregnancy. Electronic databases and journals were searched with seven articles included in this review. The findings demonstrated that women were aware of the health risks to the foetus associated with smoking; however knowledge of potential health risks was not sufficient to motivate them to quit. Se...
The structural ordering of oxygen deficient and Co-doped YBCO (YBa_2Cu_3_-_yCo_yO_6_+_x) have been studied experimentally, and by computer simulations of the oxygen ordering in the basal plane of the structure. The calculations are based on the two-dimensional ASYNNNI model and its modifications. Good agreement is established between the ASYNNNI calculations and the experimentally observed structural properties of the double cell ortho-II structure and the oxygen disordering process from Co-doping into the basal plane. A model that relates the superconducting transition temperature T_c(x) of undoped YBCO and T_c(y) of Co-doped YBCO to the formation of specific domains of the two orthorhombic ordered oxygen phases, ortho-I and ortho-II, shows a close agreement with experimental T_c(x) and T_c(y) data of samples prepared under equilibrium conditions. The structural changes as a result of metal ion substitutions and oxidation/reduction processes have been studied by neutron powder ...
Two-phase flow patterns and frictional pressure gradients in flow in small, rectangular channels are being studies as part of a larger research program addressing phase-change heat transfer of pure refrigerants and refrigerant mixtures in plate-fin heat exchangers. Small rectangular flow channels were selected as representative of plain fin geometries. The particular channel reported herein has dimensions of 19.05 {times} 3.18 mm. Adiabatic flows of air/water mixtures, with the flow channel horizontal and the channel exit at near-atmospheric conditions, were utilized in the experiments. Analysis and interpretation of the pressure data relative to observed flow pattern transitions led to an objective method for determining the plug/bubble-to-slug flow transition. This method, together with visual observations, supplemented with photographic data, was used to develop a flow pattern man. A comparison of existing flow pattern maps for circular pipes, capillary tubes, ...
Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer showers and for spring snow melt conditions, ...
Radio frequency (RF) sheaths are suspected of limiting the performance of present-day ion cyclotron range of frequencies (ICRFs) antennas over long pulses and should be minimized in future fusion devices. Within the simplest models, RF-sheath effects are quantified by the integral VRF = ? E|| ? dl where the parallel RF field E|| is linked with the slow wave. On 'long open field lines' with large toroidal extension on both sides of the antenna it was shown that VRF is excited by parallel RF currents j|| flowing on the antenna structure. In this paper, the validity of this simple sheath theory is tested experimentally on the Tore Supra (TS) ITER-like antenna prototype (ILP), together with antenna simulation and post-processing codes developed to compute VRF. The predicted poloidal localization of high-|VRF| zones is confronted to that inferred from experimental data analysis. Surface temperature distribution on ILP front face, as well as ILP-induced modifications of ...
This paper is dedicated to the numerical study of natural ventilation in a room through a large external opening using the CFD code Fluent. Bidimensional numerical simulations are performed for wind speeds up to 5.55 m-s{sup -1} (20 km-h{sup -1}). We propose a two-step solution procedure with grid refinement. When combined with appropriate thermal boundary conditions, this technique appears very efficient at limiting local convergence problems. Through an analysis of the flow pattern in the cavity, we qualitatively explain those results and define a critical Archimedes number. Calculated air change rates are compared to values deduced from empirical correlations of the literature. Agreement is in general poor, which can be explained by the differences between the conditions of our simulations and those of the experiments that lead to those correlations. However, from our simulations, we derived very clear correlations between the air change ...
Up to the present, the generic values of the Common cause failure (CCF) event parameters have been used in most PSA projects for the Korean NPPs. However, the CCF analysis should be performed with plant specific information to meet Category II of the ASME PRA Standard. Therefore, we estimated the Alpha factor parameters of the emergency diesel generator (EDG) for Ulchin Unit 3 by using the International Common-Cause Failure data Exchange (ICDE) database. The ICDE database provides the member countries with only the information needed for an estimation of the CCF parameters. The Ulchin Unit A3, pressurized water reactor, has two onsite EDGs and one alternate AC (AAC) diesel generator. The onsite EDGs of Unit 3 and 4 and the AAC are manufactured by the same company, but they are designed differently. The estimation procedure of the Alpha factor used in this study follows the approach of the NUREG/CR-5485. Since we did not find any qualitative ...
Up to the present, the generic values of the Common cause failure (CCF) event parameters have been used in most PSA projects for the Korean NPPs. However, the CCF analysis should be performed with plant specific information to meet Category II of the ASME PRA Standard. Therefore, we estimated the Alpha factor parameters of the emergency diesel generator (EDG) for Ulchin Unit 3 by using the International Common-Cause Failure data Exchange (ICDE) database. The ICDE database provides the member countries with only the information needed for an estimation of the CCF parameters. The Ulchin Unit A3, pressurized water reactor, has two onsite EDGs and one alternate AC (AAC) diesel generator. The onsite EDGs of Unit 3 and 4 and the AAC are manufactured by the same company, but they are designed differently. The estimation procedure of the Alpha factor used in this study follows the approach of the NUREG/CR-5485. Since we did not find any qualitative ...
BackgroundNatural disasters result in significant numbers of disabling impairments. Paradoxically, however, the traditional health system response to natural disasters largely neglects health-related rehabilitation as a strategic intervention.ObjectivesTo examine the role of health-related rehabilitation in natural disaster relief along three lines of inquiry: (1) epidemiology of injury and disability, (2) impact on health and rehabilitation systems, and (3) the assessment and measurement of disability.DesignQualitative literature review and secondary data analysis.ResultsAbsolute numbers of injuries as well as injury to death ratios in natural disasters have increased significantly over the last 40 years. Major impairments requiring health-related rehabilitation include amputations, traumatic brain injuries, spinal cord injuries (SCI), and long bone fractures. Studies show that persons with pre-existing disabilities are more likely to die in a ...
Combination of radiotherapy and chemotherapy (CRC) is actually one important way of research in oncology. Theoretical advantages are: (1) Spatial cooperation; (2) Additivity, which is only obtained if the toxicity of each modality are different; (3) Supra-additivity, which needs a rigorous in vitro definition; the only way to prove it is to make an isobologram analysis. This model has however, some limitations: qualitative variable could not be used, results could be different, depending on the cell line and isoeffect chosen...In fact, a supra-additivity was only demonstrated for cis platinum and etoposide. Interactions mechanisms were: (1) at the molecular level, creation of new lesions or inhibition of radiation lesions repair; (2) At the cellular level, either cytokinetic cooperation with S-phase dependent drugs, or synchronization for the drugs which blocked the cells in M-phase; (3) At the tissular level, reoxygenation, cycle ...
A method for assessing management systems for low-level radioactive waste is being developed for US Department of Energy. The method is based on benefit-cost-risk analysis. Waste management is broken down into its component steps, which are generation, treatment, packaging, storage, transportation, and disposal. Several different alternatives available for each waste management step are described. A particular waste management system consists of a feasible combination of alternatives for each step. Selecting an optimal waste management system would generally proceed as follows: (1) qualitative considerations are used to narrow down the choice of waste management system alternatives to a manageable number; (2) the costs and risks for each of these system alternatives are evaluated; (3) the number of alternatives is further reduced by eliminating alternatives with similar risks but higher costs, or those with similar costs but higher risks; (4) a ...
Purpose: The purpose of this paper is to show how Nigeria's current Universal Basic Education on primary schooling targets Muslim "Almajiri" street boys for basic literacy acquisition. The paper examines the policy's management implementation practices and challenges, as well as provides policy options that may minimize discrepancies for effective management. Design/methodology/approach: The discussion is guided by preliminary qualitative studies using phenomenology research philosophy to better understand the social realities of the boys' schooling. Using a descriptive case study approach, two schools in a major city of northern Nigeria served as research sites. Data collection process involved informal interviews, active observations, and discussions with a purpose with four boys, and two teachers as primary participants. Data analysis engaged the generation of themes from the transcribed interview and personal observation field notes, with ...
Fuel cells based on solid oxides ('SOFC') are excellent alternative devices for power generation, when they are operated at high temperature, e.g. above 600 C. Having only fixed parts for the power generating part of the device is only one advantage of the fuel cell. Due to their unique design, these devices offer a maximum of efficiency for energy conversion compared to conventional power generating systems, which are mainly based on turbines. One aim of this thesis is the examination of alternative electrolyte and cathode materials for the SOFC applications at reduced temperatures, which means in the temperature range between 600 C and 750 C. For the first main task, several materials from the oxygen ion conducting electrolytes were selected. Different strontium and magnesium doped lanthanum gallate (LSGM) materials with additional transition metal doping were selected and prepared via two different preparation methods. The optimum calcining conditions were ...
Computer-Aided Prediction of Chemical Ecotoxicity on the basis of Quantitative Structure-Activity Relationships with the Use of Physico-Chemical Descriptors, Including H-bond Parameters
Cancer, by definition, is a proliferative disease. The fundamental scientific issue explored at the international symposium "Cell Proliferation and Chemical Carcinogenesis" was the impact of chemically...Full Text Available
Chemical leucoderma is an industrial disorder in developed countries and the common causative chemicals are phenols and catechols. Due to stringent controls and preventive measures the incidence has...Full Text Available
Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not ...
Objectives. We assessed the effectiveness of various systems of community participation in ethical review of environmental health research.Methods. We used situation...Full Text Available
BackgroundInternationally, there is increasing use of telephone consultations, particularly for triaging requests for acute care. However, little is known about how this mode of...Full Text Available
BackgroundThe National Consortium for Multicultural Education for Health Professionals (Consortium) comprises educators representing 18 US medical schools, funded by the National...Full Text Available
In order to maintain a safe operation and availability of generating facilities, qualitative and quantitative assessment of piping vibration was performed vibration sources and damages of piping support was identified on the second piping system of Wolsun...
Background In May 2000, AstraZeneca launched a Web service for asthma patients and health-care providers called LinkMedica, which includes an asthma diary for...Full Text Available
In a Swedish community-based program for the treatment of dental phobic patients, a clinical trial was performed among 99 severely phobic individuals with long-standing avoidance of dental treatment....Full Text Available
PURPOSE: The purpose of this qualitative study was to explore the causes and management of blindness and blinding eye conditions as perceived by rural dwellers of two Yoruba communities in Oyo State,...Full Text Available
Background Little is known about how migrants adapt to first-world public health systems. In Norway, patients are assigned a registered general practitioner (RGP) to provide basic care...Full Text Available
Using a feminist approach, we examined the menopausal symptom experience of Hispanic midlife women in the U.S. This was a qualitative online forum study among 27 Hispanic midlife women in the...Full Text Available
Objectives To understand the perspectives of people with severe chronic obstructive pulmonary disease (COPD) as their illness progresses, and of their informal and professional carers,...Full Text Available
The full impact of secondary stigma (stigma directed at family) on an HIV-positive individual is unknown. This qualitative research explores perceptions of secondary stigma in the Vietnamese...Full Text Available
BackgroundToday, there is a trend towards establishing the medical humanities as a component of medical education. However, medical humanities programs that exist within the context...Full Text Available
BackgroundSeveral diseases, many of which nowadays pandemic, consist of multifactorial pathologies. Paradigmatic examples come from the immune response to pathogens, in which cases...Full Text Available
BackgroundResearch has shown that the long term management of food allergy is suboptimal. Our study aims to provide direction for improvement, by evaluating food allergy management...Full Text Available
Emergency Departments (ED) are fast-paced, information-intensive environments where patient care team members must address their information needs quickly and accurately. We conducted a qualitative...Full Text Available
BackgroundOsteoporosis affects over 200 million people worldwide, and represents a significant cost burden. Although guidelines are available for best practice in osteoporosis, evidence...Full Text Available
Qualitative and quantitative aspects of the mechanisms involved in the regulation of cytoplasmic pH during an acid-load have been studied in Acer pseudoplatanus cells. Two main processes,...Full Text Available
For sufficiently cool remote gases, the cylindrical stretched flame shows classical ignition-extinction behavior. For remote gas temperatures close to the adiabatic flame temperature, the flame response is qualitatively different, with negative flame speed solutions which may be physically accessible.
A simulation is developed that qualitatively describes the small-zone-gel-filtration behaviour of a reversibly associating protein. The results reflect the dependence of the apparent molecular weight...Full Text Available
BackgroundComplex situations that follow war and natural disasters have a psychosocial impact on not only the individual but also on the family, community and society. Just as the...Full Text Available
BackgroundThe first vaccine to prevent human papillomavirus (HPV) and cervical cancer has been licensed, and in future, vaccination may be routinely offered to 10–14 year...Full Text Available
The primary function of the Waste Handling Shaft (WHS) at the Waste Isolation Pilot Plant (WIPP) is to permit the transfer of radioactive waste from the surface waste handling building to the underground storage area. It also serves as an intake shaft for small volumes of air during normal storage operations and as an emergency escape route. Part of the construction was the placement of a concrete liner and steel reinforced key in 1984. During a routine shaft inspection in May 1990, some degradation of the WHS concrete liner was observed between the depths of 800 and 900 feet below the ground surface. Detailed investigations of the liner had been carried out by Sandia National Laboratories and by Westinghouse Electric Corporation Waste Isolation Division (WID) through Lankard Materials Laboratory. Observations, reports, and data support the conclusion that the concrete degradation, resulting from attack by chemically aggressive brine, is a localized phenomena. It ...
The design of separation devices, particularly for solvent-based selective removal of H{sub 2}S from CO{sub 2}, requires an accurate mathematical model. Unfortunately, this requirement for high accuracy is often in conflict with the need for efficient computation. The addition of more and more complicated analyses, such as a move from Henry's law to a method incorporating gas and liquid activities for computing vapor liquid equilibria, may give a more accurate solution, but only at the cost of decreased computational efficiency. The efforts in this work have been directed toward two goals. The first was to develop an accurate mathematical model for the aqueous methyldiethanolamine (MDEA) system. The steady-state packed column model developed in this work has been tested with data from Schubert (1988) to verify its accuracy. The second goal was to modify the model to improve its computational efficiency. Areas such as vapor-liquid equilibrium calculations, flow hydrodynamics, ...
What will be discussed in this report represents a framework upon which multiphase and other real physical effects can be built. Chemical models of increasing complexity are envisioned and this methodology can provide a tool for evaluating new ideas against known experimental data. The recent work to be reported here addresses the multiphase issue of temperature deviation between phases undergoing chemical and heat transport processes. Modeling of the LLNL ODTX experiment will be performed with FLUENT, a commercially available computational fluid dynamics (CFD) code. FLUENT solves flows in 2D or 3D in Cartesian, cylindrical, or general curvilinear coordinates, with steady-state of fully time-dependent analysis. Multiphase flows in which two or more continuous phases are present can be solved with arbitrary volumetric sources of heat, mass, momentum, and chemical species applied through user-defined ...
The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios. The measured relative K/sub ..beta..//K/sub ..cap alpha../ X-ray intensity ratios were compared to the calculated values predicted by the theoretical development of ...
The effect that different chemical and physical atomic environments can have on the relative intensities of radiative electron transitions from the filling of K shell vacancies was investigated. The method used involved the detection of photoionization induced X-ray fluorescence. An experimental system based on a hyper pure germanium detector (HPGE) was used to measure the relative K-L and K-M X-ray yields from the photofluorescence of a series of lanthanide elements and compounds. A background subtraction and peak integration strategy was employed which accounted for scattering in the samples and scattering of the flux from the radioisotope photoionization sources. Analysis of the data resulted in a tabulation of relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios. The measured relative K/sub #beta#//K/sub #alpha#/ X-ray intensity ratios were compared to the calculated values predicted by the theoretical development of Scofield and ...
The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering ...
The Energy Conversion and Storage Program applies chemistry and materials science principles to solve problems in (1) production of new synthetic fuels, (2) development of high-performance rechargeable batteries and fuel cells, (3) development of advanced thermochemical processes for energy conversion, (4) characterization of complex chemical processes, and (5) application of novel materials for energy conversion and transmission. Projects focus on transport-process principles, chemical kinetics, thermodynamics, separation processes, organic and physical chemistry, novel materials, and advanced methods of analysis. Electrochemistry research aims to develop advanced power systems for electric vehicle and stationary energy storage applications. Topics include identification of new electrochemical couples for advanced rechargeable batteries, improvements in battery and fuel-cell materials, and the establishment of engineering ...
(B204)Probabilistic risk assessment (PRA) insights are now used by the United States Nuclear Regulatory Commission (USNRC) to confirm the level of safety for plant operations and to justify changes in nuclear power plant operating requirements, both on an exception basis and as changeds to a plant's licensing basis. This report examines qualitative and quantitative risk assessments during shutdown plant states, providing feedback to utilities in the use of qualitative models for outage risk management, and also providing input to the development of the American Nuclear Society (ANS) Low Power and Shutdown PRA Standard.
(B204)Probabilistic risk assessment (PRA) insights are now used by the United States Nuclear Regulatory Commission (USNRC) to confirm the level of safety for plant operations and to justify changes in nuclear power plant operating requirements, both on an exception basis and as changeds to a plant's licensing basis. This report examines qualitative and quantitative risk assessments during shutdown plant states, providing feedback to utilities in the use of qualitative models for outage risk management, and also providing input to the development of the American Nuclear Society (ANS) Low Power and Shutdown PRA Standard.
The objective of Configuration Risk Management Program(CRMP) is to maintain the safety level by assuring the defense-in-depth of nuclear power plant while the configurations are changed during plant operations, especially for the LP/SD. Such a safety purpose can be achieved by establishing the risk monitoring programs with both quantitative and qualitative features. Generally, the quantitative risk evaluation models, i.e., PRA models are used for the risk evaluation during full power operation, and the qualitative risk evaluation models such as safety function assessment trees are used. Through this study, safety function assessment trees were developed.
This collection contains 20 papers written by educators, administrators and information scientists who had conducted manpower surveys in the library and information fields: (1) "Background and Evolution of Educational Planning and Forecasting for Information Manpower" (Yves Courrier); (2) "Indicators for the Emerging Information Market" (Nick Moore); (3) "Information Scientists in the English-Speaking Caribbean: Challenges and Responses in the Development Process" (Gloria Greene, Reive Robb); (4) "National Survey on Manpower in Libraries, Information Centres and Archives in Thailand" (Suwakhon Phadungath); (5) "Predicting the Future: Manpower Forecasting for the Library and Information Professions in Southern Africa" (J. R. Neill, D. M. Mbaakanyi); (6) "Problems in Forecasting Manpower Needs" (Monique Jucquois-Delpierre); (7) "Electronic Measures for Human Resource Research" (Anthony Debons, Mariano Maura-Sardo, Anne Thompson); (8) "The Intersection of Communication and Information: ...
This work presents an analysis of the operation of a multi-cylinder, tubro charged, indirect injection diesel engine from a second-law analysis point of view. For this purpose, a single-zone thermodynamic model following the filling and emptying modelling technique is developed. A second-law analysis is performed in all parts of the diesel engine plant, which provides all the existing availability terms and accounts for the evaluation of every component`s irreversibilities. A complete second-law terms tabulation is given for the maximum speed-full load operation case, which is compared with its first-law counterpart. A detailed parametric study is performed in all parts of the diesel engine plant comprising the effects of speed and load on the availability terms in a range that covers the whole operation of the engine under turbocharged action. Various second-law (availability) terms such as indicated and brake work, heat ...
Fact sheet on an analysis system for dyebath processes in the carpet manufacturing industry written for the NICE3 Program. The Georgia Institute of Technology (G.I.T.) has developed an effective automated dyebath analysis and reuse system that improves the energy, environmental, and economic performance of dyehouse batch operations. The new system enables dyeing solutions to be accurately monitored and adjusted for reuse. According to industry estimates, 160 pounds of water are used to produce each pound of textile product. The current wasteful batch dyeing process requires all water and residual chemicals, as well as the energy required to heat the mixture for dyeing, to be dumped after one application. Spent dyebaths can only be reused after they are sampled, analyzed, and reconstituted, a process requiring labor and expertise that are unavailable in the dyehouses. Therefore, successful commercial reuse depends on an ...
Electron probe microanalysis (EPMA) offers high sensitivity and high accuracy in quantitative measurements of chemical compositions and mass coverages. Owing to the low detection limits of the wavelength-dispersive technique, monolayers with mass coverages of about 0.05 pg cm z can be detected. Assuming a density of 5 g cm--3 this corresponds to a thickness of 0.1 nm. With these advantages in mind, EPMA was extended to depth profile analysis in the sub-micron range using a surface removal technique. The present paper shows how depth profile analysis can be improved by combining EPMA and the focused ion beam (FIB) technique. The focused ion beam system uses a Ga+ ion beam. The ion beam allows the milling of defined geometries on the nanometer scale, so that very shallow bevels with exactly defined angles in relation to the surface can be obtained. Low surface damage is expected due to low sputtering effects. Calibrated WDX ...
The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(..cap alpha..) and HgM sub(..cap alpha..) was found to be approximately 0.65 ..mu..m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 ..mu..m thick. The relation between the conposition of bulk standard determined by chemicalanalysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable ..beta..-HgS films was not caused by the nonstoichiometry, and ...
The composition of sputter-deposited HgS films was determined by electron microprobe analysis. From the relative x-ray intensity as a function of film thickness, the depth of the ionizations that produce SK sub(#alpha#) and HgM sub(#alpha#) was found to be approximately 0.65 #mu#m at an accelerating voltage of 15 kV. This value agreed well with a value calculated from Castaings' empirical law after absorption correction. The determination of film composition was limited to sufficiently thicker films than this critical value, usually 1 - 2 #mu#m thick. The relation between the conposition of bulk standard determined by chemicalanalysis and the x-ray intensity ratio was used for the correction of film composition. The results showed that the crystal structure of HgS films was independent of the composition, i.e., the growth of metastable #betta#-HgS films was not caused by the nonstoichiometry, and that the composition of ...
The possibility of a positive agricultural use of flue gas filter ash from brown coal power plants is investigated. The suggested measure is mixing ash dump surfaces with extremely acidic spoil bank soils, which balances the high pH value of the alkaline ash and contributes to improved nutrient and soil sorptive conditions. Optimum quantity of spoil bank sands in the mixture with ash is between 10% and 40%. The optimum quantity must be determined for each type of ash considering improvement of soil chemical conditions and water retention capacity. Filter ash properties vary widely; the required amount of spoil bank sand added to investigated ash surfaces near 3 brown coal power plants was between 25% and 30% of the mixture. The same favourable soil and ash mixture can be produced by adding 60% to 75% filter ash to acidic raw spoil bank soil surfaces forming a top soil layer in a thickness of minimum 60 cm. Tests of plant growth showed high crop yields in winter ...
Here in the present paper, we report on growth of stoichiometric and nonstoichiometric nanostructured heterojunction solar cell of CdS/CuInSXSe2-X varying X from 0 to 2 in the interval of 0.5 using cost effective, simple, chemical ion exchange method at room temperature on ITO glass substrate. The as-grown varying composition solar cells annealed at 200degreeC in air and characterized for structural, compositional, optical and illumination studies. The X-ray diffraction pattern obtained from CdS/CuInSXSe2-X solar cell confirms the formation of CuInSe2, CuInS0.5Se1.5, CuInS1Se1, CuInS1.5Se0.5 and CuInS2 phases having tetragonal structure with varying crystallite size from 19, 19.37, 28, 33 and 20nm respectively. The energy dispersive X-ray analysis (EDAX) confirms the expected elemental com...
In Slovenia two superb vegetable oils with high added nutritional value are produced: "Ekstra devisko oljcno olje Slovenske Istre (extra virgin olive oil from Slovene Istra)" and "Stajersko prekmursko bucno olje (pumpkin seed oil from Slovenia)". Their quality and genuineness must be monitored as adulteration can easily be undertaken. Olive oil genuineness determination experiences can show how analyses following an experience data-driven decision tree gathering several chemical determinations (fatty acids, (E)-isomers of fatty acids, sterol and tocopherol determinations) may be helpful in assessing the pumpkin seed oil from Slovenia genuineness. In the present work a set of HPLC triacylglycerol determinations was performed, based on the nine main triacylglycerols (LLLn, LLL, PLL, LOO, PLO, OOO, POO, SPL, and SLS) on a limited number of different pumpkin seed oils from northeastern Slovenia. The performed determinations showed that stereospecific analyses of ...
Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into by-products having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that SF/sub 6/, spark-decomposed under specific experimental conditions, can produce cell death. Chemicalanalysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and by-products. Biological testing of individual by-products or by-product mixtures has indicated that these major decomposition products may not account for the majority of the cell killing effects seen in our assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be produced and ...
Steam generators (SG) are the weak link of nuclear power plants, their service life is shorter than the service life of other NPP components. This paper is dedicated to a statistical analysis of SG damages and failures. Heat exchanging tubes (HET) are the most damaged elements in SG, there are on average 286 plugged or repaired tubes in each operating SG. The usually mechanisms of tube failure are the following: denting, corrosion at tube outside, pitting, fretting, and circular crack propagation. Most of damages are located in the transition zone above a tube plate. This study shows that the factors that are involved in the SG HET fault probability are: - design features of SG and secondary equipment elements (high pressure feed heaters (HPFH), low pressure feed heater (LPFH)), - water chemistry at different points of condensate feed pipe, composition and density of deposits on HET surface, efficiency of mechanical and chemical washing, - the ...
The authors have discovered chert xenoliths from green rocks in the Pippu area, central Hokkaido, Japan. Reports were given on the discovery with regard to the state of its production, chemical composition of the green rocks, and radiolarian fossils produced from the chert and their age. Considerations were given on the geological significance thereof. On 23 green rocks and five cherts out of the collected samples, rock slices were prepared, and petrographic statement was made by using a polarizing microscope. In addition, the whole petro-chemical composition analysis was performed on green rocks to discuss the radiolarian fossils and geological ages. The following conclusions were obtained as a result: green rocks may be identified as a product of igneous activities in a large plate in a certain period from the latter Callovian period of the middle age of the Jurassic period to the Barremian period of the Paleozoic era in ...
This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO2 capture. The novel combined cycle employs an air-based gas turbine, a CO2-turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about 52.2% at full-load, including CO2 compression to 200 bar. The part-load evaluation shows that reducing the load down to 60% results in an efficiency drop of 2.6%-points. However, the plant shows better relative part-load efficiency compared to conventional combined cycles. The pressure in CLC-reduction and -oxidation reactors is balanced by airflow control, using a compressor equipped with variable guide vanes. A combination of control strategies is discussed for plant start-up and shutdown and for part-load when airflow reduction is not practically possible with current generation of ...
Full text: Recent geoarchaeological research in the Erzurum district, north-eastern Anatolia, has revealed an abundance of obsidian at numerous neolithic and Bronze Age sites. Geochemical characterisation using neutron activation analysis indicates that the obsidian was obtained from several sources that are chemically distinct from the major sources already known from Central Anatolia an the Lake Van area. Multiple sources are represented in the samples collected from at least two of the sites, namely the sites of Sos and Pulur. The primary source of some of the obsidian utilised at the site of Sos has been located in the volcanic sequence outcropping tot he north-west of Pasinler. Field survey however has shown that the alluvial deposits along the main rivers and some of their tributaries were the main sources of the obsidian utilised at the sites near Erzurum. Trade or exchange of obsidian with sites outside the Erzurum area seems to have ...
Hospital wastes comprises approximately 80% domestic waste components, also known as non-risk waste and 20% hazardous or risk waste. The 20% of the hospital waste stream or the risk waste (also known as infectious, medical, clinical wastes) comprises components which could be potentially contaminated with infections, chemical or radioactive agents. Therefore, it should be handled and disposed of in such a manner as to minimize potential human exposure and cross-contamination. Hospital risk waste and be subdivided into seven general categories as follows: infections, anatomical/pathological, chemical, pharmaceutical, radioactive waste, sharps and pressurised containers. These waste categories are generated by many types of health care establishments, including hospitals, clinics, infirmaries.... The document presents also tables of number of hospitals and estimated bed number in different regions in Lebanon; estimated hospital risk and non-risk ...
In the present paper it is assumed that above a limiting value of fission fluency (burn-up) a more intensive process of irradiation introduced chemical interaction occurs. A significant part of fission gas product is thus expected to be chemically bounded in the matrix of UO_2 fuel. The fission gas atoms substituting, for example, uranium atoms in the crystallographic lattice can form weak facets. At a certain saturation condition, division of the grains can occur at the weak facets and the increase in fission-gas products release may be expected. The fact that the process of grain division for high burn-ups (70-80 MWd/kgU) forms an extremely fine structure up to the temperature as high as 1100 "oC and simultaneously the observed decreases in fission gas concentration in the fuel supports this concept. The analysis of fission gas concentration change due to the formation of nanostructures in UO_2 fuel at high burn-ups in ...
Macromolecular and polyanionic Na(+)-poly(gamma-glutamic acid) (PGA) silver nitrate complex acted as both a metal ion provider and a particle protector to fabricate nanosized silver colloids under chemical reduction by dextrose. The formation and size of particles have been characterized from transmission electron microscopy (TEM), dynamic light scattering analysis and UV-vis spectrophotometer. The results showed that the average particle size was 17.2+/-3.4 to 37.3+/-5.5 nm, apparently depending on the complex concentration. It was found that the rate constant and conversion of silver nanoparticles were proportional to the concentration of PGA. The growth mechanism of nanosized silver colloid was fully discussed. In addition, the in vitro cytotoxicity evaluated by L929 fibroblasts proliferation and antibacterial activity against Gram-positive strain (methicillin-resistant S. aureus (MRSA)) and Gram-negative strain (P. aeruginosa) bacteria have ...
In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics ...
In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics ...
The effect of hydrogen sulfide (H2S) on the chemical looping combustion of coal-derived synthesis gas with bentonite-supported metal oxidesssuch as iron oxide, nickel oxide, manganese oxide, and copper oxideswas investigated by thermogravimetric analysis, mass spectrometry, and X-ray photoelectron spectroscopy (XPS). During the reaction with synthesis gas containing H2S, metal-oxide oxygen carriers were first reduced by carbon monoxide and hydrogen, and then interacted with H2S to form metal sulfide, which resulted in a weight gain during the reduction/sulfidation step. The reduced/sulfurized compounds could be regenerated to form sulfur dioxide and oxides during the oxidation reaction with air. The reduction/oxidation capacities of iron oxide and nickel oxide were not affected by the presence of H2S, but both manganese oxide and copper oxide showed decreased reduction/oxidation capacities. However, the rates of reduction and oxidation ...
The Hanford Site, Richland, Washington, contains over 1,500 identified waste sites and numerous groundwater plumes that will be characterized and remediated over the next 30 years. As a result of the Hanford Federal Facility Agreement and Consent Order, the US Department of Energy (DOE) has initiated a remedial investigation/feasibility study (RI/FS) at the 200-BP-1 operable unit. The 200-BP-1 RI/FS is the first Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) investigation on the Hanford Site that involves highly radioactive and chemically contaminated soils. The initial phase of site characterization was designed to assess the nature and extent of contamination associated with the source waste sites within the 200-BP-1 operable unit. Characterization activities consisted of drilling and sampling, chemical and physical analysis of samples, and development of a conceptual vadose zone model. ...
Modification of DNA and double-stranded deoxyoligonucleotides with antitumor 1,2-diamino-cyclohexanedinitroplatinum(II) (Pt-dach) complexes was investigated with the aid of physico-chemical methods and chemical probes of nucleic acid conformation. The three Pt-dach complexes were used which differed in isomeric forms of the dach non-leaving ligand-Pt(1R,2R-dach), Pt(1S,2S-dach) and Pt(1R,2S-dach) complexes. The latter complex has lower antitumor activity than the other two Pt-dach complexes. Pt(1R,2S-dach) complex exhibits the slowest kinetics of its binding to DNA and of the conversion of monofunctional binding to bifunctional lesions. The anomalously slow electrophoretic mobility of multimers of the platinated and ligated oligomers suggests that bifunctional binding of Pt-dach complexes to a d(GG) site within double-stranded oligonucleotides induces bending of the oligomer. It is proposed that different effects of the Pt-dach complexes on DNA ...
The Korea Atomic Energy Research Institute has launched a decommissioning program of uranium conversion plant. One of the important tasks in the decommissioning program is the treatment of the sludge, which was generated during operation and stored in the two ponds of the lagoon. The treatment requires the volume reduction of lagoon sludges for the low cost of the program and the conversion of the chemical forms, including uranium, for the acceptance at the final disposal site. The physical properties, such as densities, were measured and chemical compositions and radiological properties were analyzed. The denitration was a candidate process which would satisfy the requirements for sludge treatment, and the characteristics of thermal decomposition and dissolution with water were analyzed. The main compounds of the sludge were ammonium and sodium nitrate from conversion plant and calcium nitrate, calcium carbonate from Ca precipitation and ...
The aim of the study is to prepare ionic exchangers using the polymerization of unsaturated polyster with monomeric styrene units in a ratio of 60%: 40% respectively. The type of method involved in this preparation, is called An Emulsion Polymerization. Such type of polymerization was carried out by two techniques: chemical and irradiation techniques. The first techniques requires the formation of free radical monomers by use of methyl Ethy Ketone Peroxide capable of decomposing into free radicals upon heating, while the other technique involves the use of gamma rays (using Co-60 source) capable of activating monomers towards free radical formations. A number of very effective chemical parameters and physical factors were used and investigated throughout the reactions such as: dispersant matrix, viscosity, rate of mixing, and irradiation dose. Besides, the study has included the study of the rate of Resin Beads Swelling which is thought to be ...
Chemical oxidation is a treatment technology that uses powertul chemical oxidizers to destroy organic contaminants. Typical oxidizers used in chemical oxidation processes include ozone, hydrogen peroxide, chlorine, and potassium permanganate. The chemical reaction products are usually simple organic compounds, such as carboxylic acids, and/or inorganic compounds, such as carbon dioxide, water, and simple inorganic complexes (e.g., chloride salts, in the case of chemical oxidation treatment of chlorinated solvents).
Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.
This paper presents studies carried out on tin-doped indium sulfide films prepared using Chemical Spray Pyrolysis (CSP) technique. Effect of both in-situ and ex-situ doping were analyzed. Ex-situ doping was done by thermal diffusion, which was realized by annealing Sn/In2S3 bilayer films. In-situ doping was accomplished by introducing Sn into the spray solution by using SnCl45H2O. Interestingly, it was noted that by ex-situ doping, conductivity of the sample enhanced considerably without affecting any of the physical properties such as crystallinity or band gap. Analysis also showed that higher percentage of doping resulted in samples with low crystallinity and negative photosensitivity. In-situ doping resulted in amorphous films. In contrast to ex-situ doping, `in- situ doping' resulted i...
The evaluation methodology utilized in deciding to change over Oyster Creek plant operation from chemical regeneration of condensate demineralizer resin beds to throwaway of this spent resin is presented. Both the economic and operational aspects considered are discussed. The evaluation shows that potential savings in the $1.1M range are feasible over a 5 year cycle. Cost sensitivity analysis results define the throwaway versus regeneration breakeven point to be 47 condensate demineralization beds per 5 year cycle. The evaluation also discusses the trade off between resin and evaporator concentrates burial volumes. Analyses are given which show that the burial volume cost equivalency of resin to solidified concentrates is 150 ft./sup 3/ of resin equals 400 ft./sup 3/ of concentrates. Based on one year of power operation in the throwaway mode, the savings and operational value anticipated in the initial study are being realized.
A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.
This poster presentation gave an overview of the subaqueous deposition of reactive mine tailings in the open trench Don Rouyn, located near Rouyn-Noranda, Quebec. The author began by providing a brief background of subaqueous mine tailing storage, and discussed the interest of the Don Rouyn trench. The site was described according to geomorphological and geological aspects. The hydrology conditions existing at the site were mentioned, and the results of the hydrology analysis performed were indicated. Close monitoring of the situation was maintained, and the chemical and physical stability of the tailings were evaluated. The conditions that prevailed both before and after the flooding of the site were explained. Water quality is being monitored, and the results obtained at this site might be used at other locations. 40 figs.
Various chemical, physical, and mechanical methods to prevent unwanted deposition of mineral scale are described. The suitability of the different methods, which largely depends on the specific features and requirements of the system involved, is discussed. Special emphasis is placed upon the threshold treatment, where the growth process is retarded by the addition of trace amounts of growth inhibitors. Growth experiments have been performed on barium sulfate and calcium sulfate dihydrate seed crystals, suspended in a supersaturated solution with and without organic bisphosphonates as inhibitors. Two methods are selected for the analysis of the growth data. A degree of inhibition is defined to obtain a quantitative description of the influence of a growth inhibitor on the growth rate of the crystals. In addition the influence of the molecular structure of various bisphosphonates with different substituents is shown. The effect of a ...
Aqueous radioactive high-level waste slurries are combined during processing steps that ultimately produce a stable borosilicate glass waste form. Chemically treated waste slurries are combined with each other and with glass frit-water slurries to produce the melter feed. Understanding the evolution of the rheological properties of the slurries is an important aspect of removing and treating the stored waste. To a first approximation, combinations of colloidal waste slurry with {approx}0.1-mm mean diameter glass frit or glass beads act in an analogous matter to slurries of spherical beads in Newtonian liquids. The non-Newtonian rheological properties of the waste slurries without frit, however, add complexity to the hydrodynamic analysis. The use of shear rate dependent apparent viscosities with the modified Einstein equation was used to model the rheological properties of aqueous frit-waste slurries.
Abstract Incomplete dispersion of aggregates is a well known difficulty when analyzing soil texture of Andosols, particularly if no fresh soil material is available. To facilitate such investigations, several dispersion procedures were carried out on air dried samples rich in short range order minerals, originating from selected Andosol profiles (S Mexico). As a result, we propose an improved method based on a sequential chemical treatment with K oxalate, NH4 oxalate, and oxalic acid that reliably removes cementing agents and allows for a stable dispersion of soil particles after addition of Na pyrophosphate. This method was proved to be well reproducible and highly reliable for routine grain size determinations. The potential error caused by the inherent risk of dissolving primary mineral...
Through an international collaborative effort, a special version of the CONTAIN code is being developed for integrated mechanistic analysis of the conditions in liquid metal reactor (LMR) containments during severe accidents. The capabilities of the most recent code version, CONTAIN LMR/1B-Mod.1, are discussed. These include new models for the treatment of two condensables, sodium condensation on aerosols, chemical reactions, hygroscopic aerosols, and concrete outgassing. This code version also incorporates all of the previously released LMR model enhancements. The results of an integral demonstration calculation of a sever core-melt accident scenario are given to illustrate the features of this code version. 11 refs., 7 figs., 1 tab.
Two new triterpene glycosides, patagonicosides B and C (2 and 3, resp.), together with the known patagonicoside A (1), have been isolated from the EtOH extract of the sea cucumber Psolus patagonicus. The structures of the new compounds were established on the basis of extensive NMR spectroscopic analysis ((1)H- and (13)C-NMR, (1)H,(1)H-COSY, HMBC, HSQC, TOCSY, and NOESY), HR-ESI-MS data, and chemical transformations. Compounds 1-3 and their desulfated analogs showed antifungal activities against the phytopathogenic fungus Cladosporium cladosporoides in a dose-dependent fashion. PMID:21404430
Nuclear approaches for compositional characterization has bright application prospect in forensic perspective towards assessment of nature and origin of seized material. The macro and micro physical properties of nuclear materials can be specifically associated with a process or type of nuclear activity. Under the jurisdiction of nuclear analytical chemistry as well as nuclear forensics, thrust areas of scientific endeavor like determination of radioisotopes, isotopic and mass ratios, analysis for impurity contents, arriving at chemical forms/species and physical parameters play supporting evidence in forensic investigations. The analytical methods developed for this purposes can be used in international safeguards as well for nuclear forensics. Nuclear material seized in nuclear trafficking can be identified and a profile of the nuclear material can be created
The final product of the radwaste conditioning process must satisfy certain requirments and physico-chemical properties in order to assure its safe long-term behaviour. Of course, the foreseen quality assurance and quality control should be conducted by means of non-destructive techniques. This work presents an over-view of various applicable non-destructive methods of analysis, showing their fields of investigation in testing waste packages, together with some arising practical problems. The most promising methods, such as eddy current testing, ultrasonic testing, #gamma#-scanning, #gamma#-spectroscopy, neutron counting and computerized tomography, are treated more deeply and some applications are presented. Particular attention is devoted to the development of a device based on computerized tomography; its essential components are reported and some design problems are also discussed.
The effect of sugar on plant metabolism, which is known to be similar to hormone-like signaling, was metabolomically studied using Melissa officinalis (lemon balm). The metabolite profiles of M. officinalis treated with sucrose were analyzed by gas chromatography-mass spectrometry (GC-MS) and principal component analysis (PCA). A total of 64 metabolites from various chemical classes including alcohols, amines, amino acids, fatty acids, inorganic acids, organic acids, phosphates, and sugars were identified by GC-MS. Three groups treated with different sucrose concentrations were clearly separated by PCA of their metabolite profiles, indicating changes in the levels of many metabolites depending on the sucrose concentration. Metabolite profiling revealed that treatment with a higher sucrose ...
The research committee of the Atomic Energy Society of Japan on water chemistry standard aims at establishing the private standard of water chemistry of nuclear power plants. The committee gathers up 'BWR water chemistry management manual', 'PWR primary system water chemistry management manual' and 'PWR water chemicalanalysis standard method', and furthermore aims at the standardization of those in future. Looking back on the committee's activities for the past four years, latest results of research of water chemistry mainly contributing to safe and reliable nuclear power plants were described with the future perspective of water chemistry and a demanded break-through. (T.T.)
This paper presents three non-linear asymptotic observers corresponding to three examples of engineering interest: a chemical reactor, a non-holonomic car, and an inertial navigation system. For each example, the design is based on physical symmetries. This motivates the theoretical development of invariant observers, i.e, symmetry-preserving observers. We consider an observer to consist in a copy of the system equation and a correction term, and we give a constructive method (based on the Cartan moving-frame method) to find all the symmetry-preserving correction terms. They rely on an invariant frame (a classical notion) and on an invariant output-error, a less standard notion precisely defined here. For each example, the convergence analysis relies also on symmetries consideration with a key use of invariant state-errors. For the non-holonomic car and the inertial navigation system, the invariant state-errors is shown to obey an autonomous ...
In QCD the spontaneous breaking of chiral symmetry and the U(1) axial anomaly can be understood considering instantons as the gauge configurations mediating quark-quark interaction. The existence of an exact zero mode solution of the Dirac equation in the field of a single instanton is the fundamental ingredient of this analysis. Explicit expressions for psi_0 are available for T different from 0 and mu=0, and mu different from 0 and T=0. In this paper we derive the solution for the most general case T different from 0 and mu different from 0. This new result opens the possibility of investigating the QCD dynamics associated with instantons in the full phase diagram. As a first step in this direction we will study the dependence of the instanton density from the thermodynamic coordinates.
Research on hematological disorders relies on suitable animal models. We retrospectively evaluated the use of the hematological parameters hematocrit (HCT), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), red blood cell count (RBC), white blood cell count (WBC), and platelet count (PLT) in the phenotype-driven Munich N-ethyl-N-nitrosourea (ENU) mouse mutagenesis project as parameters for the generation of novel animal models for human diseases. The analysis was carried out on more than 16,000 G1 and G3 offspring of chemically mutagenized inbred C3H mice to detect dominant and recessive mutations leading to deviations in the levels of the chosen parameters. Identification of animals exhibiting altered valu...
The comprehensive theoretical and experimental study of the adsorption of water and methanol molecules on active sites (carboxyl and phenol hydroxyl groups) on the graphitized thermal carbon black is performed. It is shown that microclusters formed upon the adsorption of these molecules on such sites are characterized by the cyclic structure comprising 4?5 molecules similar to that whose existence was revealed previously in liquid water and on the surface of silver iodide. The analysis of the studied adsorption clusters demonstrated that the formation of such cycles is governed primarily by the hydrogen bonding; however, a definite role is played also by energy effects associated with the changes in the state of molecular motion during adsorption. It is shown that the generalized Langmuir ...
A new technique has been developed for the measurement of steam mass flowrate, water mass flowrate and total enthalpy of two-phase fluids produced from geothermal wells. The method involves precisely metered injection of liquid and vapor phase tracers into the two-phase production pipeline and concurrent sampling of each phase downstream of the injection point. Subsequent chemicalanalysis of the steam and water samples for tracer content enables the calculation of mass flowrate for each phase given the known mass injection rates of tracer. This technique has now been used extensively at the Coso geothermal project, owned and operated by California Energy Company. Initial validation of the method was performed at the Roosevelt Hot Springs geothermal project on wells producing to individual production separators equipped with orificeplate flowmeters for each phase.
The effects of boron addition on weldability and high temperature strength properties were investigated for Hastelloy alloy XR used TIG welding process with the filler metals. Four versions of filler metals with different boron contents were used. The results obtained may be summarized as follows: (1) The influence of boron addition on weldability was not observed within the range of the present experiment. (2) The result of chemicalanalysis for deposited metals showed that boron desorption did not occur during welding. (3) The tensile properties of weldments, particularly in high temperature ductility were raised with increasing boron content. (4) In the creep properties of weldments, creep rupture life increased with increasing boron content under the given stress conditions. (author).
The effects of boron addition on weldability and high temperature strength properties were investigated for Hastelloy alloy XR used TIG welding process with the filler metals. Four versions of filler metals with different boron contents were used. The results obtained may be summarized as follows: 1) The influence of boron addition on weldability was not observed within the range of the present experiment. 2) The result of chemicalanalysis for deposited metals showed that boron desorption did not occur during welding. 3) The tensile properties of weldments, particularly in high temperature ductility were raised with increasing boron content. 4) In the creep properties of weldments, creep rupture life increased with increasing boron content under the given stress conditions. (author).
Irradiation processing of food in the prepackaged form may affect chemical and physical properties of the plastic packaging materials. The effect of #gamma#-irradiation doses (2.5-10.0 kGy) on polypropylene (PP)-based retortable food packaging materials, were investigated using Fourier transform infrared (FTIR) spectroscopic analysis, which revealed the changes happening to these materials after irradiation. The mechanical properties decreased with irradiation while oxygen transmission rate (OTR) was not affected significantly. Colour measurement indicated that Nylon 6 containing multilayer films became yellowish after irradiation. Thermal characterization revealed the changes in percentage crystallinity.
Material degradation of pressure tubes, which are the most important components in CANDU fuel channel, can only be evaluated by removing and examining them(material surveillance). This study aimed at establishment of overall evaluation technology including the evaluation of the material degradation for the integrity of pressure tubes of Wolsung units. Material tests for pressure tubes were performed as follows; (1) Evaluation on life limiting factors of pressure tubes (2) Review on leak-before-break and integrity maintenance technology of pressure tubes (3) Survey on selection criteria for tubes to be inspected and on related regulations for material surveillance (4) Analysis of material surveillance test procedure (5) Basic examinations of Wolsung unit 1 pressure tube material(TEM, texture, chemical component etc) (6) Manufacture of test equipments and test (DHCV, hydriding, grip and tensile specimen etc). 23 figs, 6 tabs, 59 refs. (Author).
The introduction of automation technology into the analytical laboratory holds the promise of higher efficiency, improved productivity, and lower costs. However, the conventional ''laboratory robot'' widely used today may not offer the work envelope or reliability required in a high workload laboratory performing quality control or environmental analytical services. To address this need, a demonstration workcell was assembled utilizing an industrial-class robotics system to automate a standard EPA acid digestion protocol. With further development of graphical user interfaces and error recovery software, the technology will significantly enhance the ability of laboratories to meet increasingly complex environmental demands. 7 refs., 2 figs., 1 tab.
This paper examines cupric chloride solid conversion during hydrolysis in a thermochemical copper-chlorine (Cu-Cl) cycle for hydrogen production. The hydrolysis reaction is a challenging step, in terms of the excess steam requirement and the decomposition of cupric chloride (CuCl_2) into cuprous chloride (CuCl) and chlorine (Cl_2). The hydrolysis and decomposition reactions are analyzed with respect to the chemical equilibrium constant. The effects of operating parameters are examined, including the temperature, pressure, excess steam and equilibrium conversion. A maximization of yield and selectivity are very important. Rate constants for the simultaneous reaction steps are determined using a uniform reaction model. A shrinking core model is used to determine the rate coefficients and predict the solid conversion time, with diffusional and reaction control. These new results are useful for scale-up of the engineering equipment in the thermochemical Cu-Cl cycle for ...
The contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages were investigated depending on hot smoking conditions (glow smoke). For the 24 smoking experiments (performed in duplicates) three different smoke densities and ventilator velocities as well as wood chips with five different moisture contents were tested. During the smoking process, concentrations of O"2, CO"2 and CO, humidity and temperature in the smoking chamber as well as smoke generation temperature were determined. The chemicalanalysis included the contents of the 15+1 EU priority PAH and the phenolic substances guaiacol, 4-methylguaiacol, syringol, eugenol and trans-isoeugenol. The smoking conditions had a significant influence on smoke generation temperature, organoleptic pr...
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 chemicalanalysis 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.
We developed a surrogate mixture model to represent the physical properties of a coal-derived liquid fuel using only information obtained from a gas chromatography-mass spectrometry analysis of the fuel and a recently developed 'advanced distillation curve'. We then predicted the density, speed of sound, and viscosity of the fuel and compared them to limited experimental data. The surrogate contains five components (n-propylcyclohexane, trans-decalin, {alpha}-methyldecalin, bicyclohexane, and n-hexadecane), yet comparisons to limited experimental data demonstrate that the model is able to represent the density, sound speed, and viscosity to within 1, 4, and 5%, respectively. 102 refs., 2 figs., 5 tabs.
The use of Auger electron spectroscopy (AES) combined with in situ sputter etching for revealing the metallurgy of the metal-semiconductor interface is presented. The physical basis, measurement techniques, and data interpretation for Auger analysis of thin-film structures are briefly reviewed. Results of a detailed study of an alloyed multilayered contact (Ni/Au-Ge) on n-type epitaxial GaAs are summarized to illustrate how electrical and metallurgical contact properties can be correlated using AES. In addition, the results of a study of the growth kinetics and chemical phase identification of palladium silicide on single-crystal Si is given, as well as the initial results of a study of aluminum-palladium silicide interaction at elevated temperature. (auth)
The use of Auger electron spectroscopy (AES) combined with in situ sputter etching for revealing the metallurgy of the metal-semiconductor interface is presented. The physical basis, measurement techniques, and data interpretation for Auger analysis of thin-film structures are briefly reviewed. Results of a detailed study of an alloyed multilayered contact (Ni/Au-Ge) on n-type epitaxial GaAs are summarized to illustrate how electrical and metallurgical contact properties can be correlated using AES. In addition, the results of a study of the growth kinetics and chemical phase identification of palladium silicide on single-crystal Si is given, as well as the initial results of a study of aluminum-palladium silicide interaction at elevated temperature.
Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.
In nuclear fuel, in approximately one quarter of the fissions, one of the two formed fission products is gaseous. These are mainly the noble gases xenon and krypton with isotopes of xenon contributing up to 90% of the product gases. These noble fission gases do not combine with other species, and have a low solubility in the normally used uranium oxide matrix. They can be dissolved in the fuel matrix or precipitate in nanometer-sized bubbles within the fuel grain, in micrometer-sized bubbles at the grain boundaries, and a fraction also precipitates in fuel pores, coming from fuel fabrication. A fraction of the gas can also be released into the plenum of the fuel rod. With increasing fission, and therefore burn-up, the ceramic fuel material experiences a transformation of its structure in the 'cooler' rim region of the fuel. A subdivision occurs of the original fuel grains of few microns size into thousands of small grains of sub-micron sizes. Additionally, larger ...
Construction and commissioning period of NPP are reduced world over drastically by stringent schedule for financial and economic reasons. For meeting the schedule, commissioning of components and systems are started immediate after installation, while construction activities are continued in parallel at the same place. Parallel activities' and 'Time Constraint' have brought new challenges to 'Management of Fire and Industrial Safely' during commissioning. An innovative approach was used during such phase of commissioning of TAPP-3 and 4. This paper outlines challenges encountered during this phase and special approach and measures used to meet those challenges. This paper also outlines problems encountered during implementation of these measures and subsequent change in approach to ensure smooth and safe execution of activities. Primarily, challenges were conflicting requirements by various agencies to carryout commissioning in parallel with construction activities concurrently. Main ...
The 177 underground storage tanks at the DOE's Hanford Site contain an estimated 180 million tons of high-level radioactive wastes. It is desirable to remove and concentrate the highly radioactive fraction of the tank wastes for vitrification. Resorcinol-formaldehyde (R-F) resin, an organic ion-exchange resin with high selectivity and capacity for the cesium ion, which is a candidate ion-exchange material for use in remediation of tank wastes. The report includes information on the structure/function analysis of R-F resin and the synthetic factors that affect performance of the resin. CS-100, a commercially available phenol-formaldehyde (P-F) resin, and currently the baseline ion-exchanger for removal of cesium ion at Hanford, is compared with the R-F resin. The primary structural unit of the R-F resin was determined to consist of a 1,2,3,4-tetrasubstituted resorcinol ring unit while CS-100, was composed mainly of a 1,2,4-trisubstituted ring. CS-100 shows the ...
Gas-insulated systems employing SF/sub 6/ are utilized in a variety of applications in power delivery systems. Because electric arcs, sparks or corona can decompose SF/sub 6/ into byproducts having chemical properties different from SF/sub 6/, environmental concerns arise regarding inadvertent human exposures to electrically-decomposed SF/sub 6/. Biological assays in our laboratory using mammalian cell culture systems have revealed that spark-decomposed SF/sub 6/ produces cell death, and the extent of cell killing increases with increasing spark energy. Chemicalanalysis of spark-decomposed SF/sub 6/ has identified the major decomposition pathways and byproducts, but biological testing of individual or byproduct mixtures has indicated that these major decomposition products do not contribute, in a significant fashion, to the cell lethality seen in our assays. Further experiments have suggested that S/sub 2/F/sub 10/ may be ...
The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, ...
Sulfuric acid and its partially or completely neutralized salts with ammonia are believed to result from the oxidation of sulfur dioxide in cloud water and in other heterogeneous media present in the atmosphere. Due to the natural abundance of ammonia and the ubiquitous presence of sulfur in the atmosphere, (NH/sub 4/)/sub 2/SO/sub 4/ is commonly the dominant chemical species in the ambient aerosol. The amounts of ammonium sulfates are expected to be very low in areas far removed from anthropogenic emissions of sulfur dioxide. The chemical composition of submicrometer aerosol particles was determined at the Mauna Loa Observatory (MLO) on Mauna Loa in Hawaii during an eight-day period in August 1986. The MLO site was selected for this measurement because it is the only ground-based aerosol observatory in the remote Pacific Ocean that allows extended sampling of aerosols in the free troposphere. Measurements were made using an attenuated total ...
Peroxisome proliferating agents (PPAs) are a structurally diverse group of chemicals that include environmental chemical contaminants such as certain chlorinated herbicides, solvents and plasticizers. PPAs have previously been shown to induce anti-trout laruci acid hydroxylase immunoreactive proteins in bluegill and catfish. In this investigation, induction of lauric acid hydroxylase activity and immunoreactive proteins was confirmed, and the mass spectral analysis of specific hydroxylation products was performed in order to identify possible species-specific differences in fatty acid metabolism. Male bluegill (Lepomis macrochirus) and channel catfish (Ictalurus punctatus) were administered clofibrate or ciprofibrate 48 hr prior to hepatic or trunk kidney (catfish only) microsome preparation. While no significant differences were observed in male catfish, male bluegill had significant decreases in hematocrit and plasma ...
Organic materials released from energy-related activities could affect human health and the environment. To better assess possible impacts, we developed a model to predict the fate of spills or discharges of pollutants into flowing or static bodies of fresh water. A computer code, Aquatic Pathways Model (APM), was written to implement the model. The computer programs use compartmental analysis to simulate aquatic ecosystems. The APM estimates the concentrations of chemicals in fish tissue, water and sediment, and is therefore useful for assessing exposure to humans through aquatic pathways. The APM will consider any aquatic pathway for which the user has transport data. Additionally, APM will estimate transport rates from physical and chemical properties of chemicals between several key compartments. The major pathways considered are biodegradation, fish and sediment uptake, photolysis, and evaporation. ...
Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X = 1 {mu}m and an intermediate inter-pillar gap size of Y = 4 {mu}m with superhydrophobic CAs over 170 . Surface analysis with X-ray photoelectron ...
In most conceptual fusion power reactor designs, it is proposed to use beryllium as a neutron multiplier in the blanket. Detailed chemical composition of beryllium is necessary for evaluation of the tritium breeding ratio, and estimating the activation and transmutation of beryllium in the fusion reactor. In the present report, special attention was paid to a detailed analysis of impurities in beryllium, relevant to the tritium breeding ratio evaluation. Two different methods were used for the study of impurities: an analysis of the local sample by the ICP-MS method, and an integral analysis of the beryllium assembly, using the pulsed neutron method. The latter method was proposed as the most effective way of analyzing the integral effect to impurities in beryllium on production of the tritium on the lithium-6. The evaluation of the integral effect was based on time behaviour observations of the thermal ...
Pentaerythritol tetranitrate (PETN) is a relatively sensitive explosive used in many electroexplosive devices as well as in medicine. Of primary interest to LLNL is its use in items such as exploding bridgewire (EBW) detonators and exploding bridge foil initiators (EFI). In these devices the crystalline powder is pressed into a granular, low-density compact that can be initiated by an exploding wire or foil. The long-term stability of this pressed compact is of interest to weapon stockpile lifetime prediction studies. Key points about potential aging mechanisms can be summarized as follows: (1) There are a number of factors that can contribute to PETN instability. These include particle size, polymorphic phase transitions, crystal structure, impurities, moisture, occlusions, chemical incompatibility and biological (microorganism) action. of these factors the most important for long-term aging of high surface area powders used in detonators appears to be that of ...
Chemical phase identifications of complex, multilayered corrosion products formed on Fe-Ni-Cr alloys immersed in molten NaNO/sub 3/-KNO/sub 3/ and LiNO/sub 3/-NaNO/sub 3/-KNO/sub 3/ were obtained by X-ray diffraction analysis. Diffraction analyses performed after successive material removal steps provided depth profiles of corrosion products and identified the dominant phases as NaFeO/sub 2/, Fe/sub 3/O/sub 4/, and Cr/sub 2/O/sub 3/ for Alloy 800 and 316SS after immersion in NaNO/sub 3/-KNO/sub 3/. In LiNO/sub 3/-NaNO/sub 3/-KNO/sub 3/, the major corrosion products identified on Alloy 800 were LiFeO/sub 2/, Fe/sub 3/O/sub 4/, and Cr/sub 2/O/sub 3/. X-ray diffraction results were supplemented by electron microprobe analyses that revealed the solid solution nature of several of the oxide phases.
Emerging evidence suggests that E3 ligases play critical roles in diverse biological processes, including innate immune responses in plants. However, the mechanism of the E3 ligase involvement in plant innate immunity is unclear. We report that a rice gene, OsBBI1, encoding a RING finger protein with E3 ligase activity, mediates broad-spectrum disease resistance. The expression of OsBBI1 was induced by rice blast fungus Magnaporthe oryzae, as well as chemical inducers, benzothiadiazole and salicylic acid. Biochemical analysis revealed that OsBBI1 protein possesses E3 ubiquitin ligase activity in vitro. Genetic analysis revealed that the loss of OsBBI1 function in a Tos17-insertion line increased susceptibility, while the overexpression of OsBBI1 in transgenic plants conferred enhanced resi...
The admissibility of nuclear forensics measurements and opinions derived from them in US Federal and State courts are based on criteria established by the US Supreme Court in the case of Daubert v. Merrell Dow and the 2000 Amendment of Rule 702 of the Federal Rules of Evidence. These criteria are being addressed by new efforts that include the development of certified reference materials (CRMs) to provide the basis for analytical method development, optimization, calibration, validation, quality control, testing, readiness, and declaration of measurement uncertainties. Quality data is crucial for all stages of the program, from R and D, and database development, to actual casework. Weakness at any point in the program can propagate to reduce the confidence of final conclusions. The new certified reference materials will provide the necessary means to demonstrate a high level of metrological rigor for nuclear forensics evidence and will form a foundation for legally defensible nuclear ...
The contamination of environmental materials (soil and dust) by heavy elements is of concern in assessing environmental pollution. Characterization of samples is performed in order to provide information that can be used to assess the potential hazard of the material, to assess remediation strategies, and to determine the source of the heavy element-bearing material. Microbeam analysis using a scanning electron microscope (SEM) or electron microprobe on polished particle mounts allows the size, internal morphology and chemical composition to be determined on a particle-by-particle basis. Computer controlled SEM allows all factors except internal structure to be acquired in an automated fashion. The authors present examples of two studies using microbeam techniques. In the first example, they illustrate how cadmium associated with sphalerite in soils can be quantified at levels down to a few parts per million (ppm) using computer controlled SEM ...
Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to ...
A test to determine the lithium compatibility and impurity gettering capabilities of various materials including yttrium was performed in Beryllium-7 Experimental Lithium (7BELL) at 270/sup 0/C. Yttrium coupons were exposed in liquid lithium for a total of 3,718 hours. X-ray diffraction and bulk chemicalanalysis data indicated that yttrium absorbs hydrogen from liquid lithium at 270/sup 0/C and transforms to yttrium dihydride (YH/sub 2/). The transformation of yttrium to YH/sub 2/ resulted in embrittlement of the coupons and subsequent fragmentation to small pieces. Additional analysis, based on the equilibrium hydrogen pressures for the transition of yttrium to YH/sub 2/, and Sievert's relationship for hydrogen in equilibrium with hydrogen in lithium, indicates that the temperature of yttrium cannot exceed 280/sup 0/C to control the hydrogen concentration in lithium at below 1 wt ppm. It is concluded in general ...
Stainless steel is pickled in pickling bath with the sulfuric acid and a mixture of hydrofluoric acid and nitric acid. Suitable equipment based on speedy and accurate chemicalanalysis for actual production lines has not been developed yet. The concentration of sulfuric acid can be analyzed by using the neutralization titration method. As a method of analyzing hydrofluoric acid in the mixed acid, the iron-acetylacetone complex discoloration absorbance method was adopted. For the concentration, of nitric acid, the method of subtracting the concentration of hydrofluoric acid from the total mixed acid amounts obtained by neutralization titration is adopted. Furthermore, the iron-salicylic acid complex absorbance method is adopted as a method of analyzing the iron content. By adopting these methods, the fully automated analyzer is developed. Completing analysis work can be shortened to 40 minutes by automated sampling from the ...
This quarterly report for the period April through June 1984 summarizes activities in Sandia National Laboratories' continuing program of coal liquefaction research. The primary goals are to: explore novel catalytic concepts and materials for conversion of coal to liquid fuels; determine the effects of process variables on catalyst deactivation; determine the effects of coal structure and solvent properties on low temperature dissolution; study the kinetics and catalysis of hydrogen transfer reactions; develop an understanding of slurry gelling phenomena; and provide a technical assessment of coal liquefaction processes. During this period, work was performed on: analysis of catalyst samples from Wilsonville Run 246; catalyst presulfiding; catalyst activity testing using pyrene as a chemical probe; catalyst deactivation using a high-pressure model compound test reactor; dissolution chemistry of Wyodak coal; slurry gelling utilizing the ...
In this study, perovskite type oxide YAlO_3 has been doped with different amounts of the divalent cation Ca to synthesize Y_1_-_xCa_xAlO_3_-_#delta# (x = 0-0.21) compositions. The effect of dopant concentration on the crystal structure and electrical properties of YAlO_3 synthesized by citrate gel route has been investigated. The phase purity of the samples has been carried out using X-ray diffraction. The microstructural evaluation of the samples has been conducted by scanning electron microscopy and energy dispersive spectrum analysis. Thermal analysis has been conducted to monitor the decomposition of the intermediate products. The electrical conductivity studies have been performed using a.c. impedance spectroscopy as a function of temperature in the range 200-800 "oC in air. The Y_0_._9_4Ca_0_._0_6AlO_3_-_#delta# composition exhibits a total conductivity of 2.5 mS/cm at 800 "oC.
We have derived elemental abundances for a sample of nine IRAS sources with colours similar to those of post-AGB stars. For IRAS 01259+6823, IRAS 05208-2035, IRAS 04535+3747 and IRAS 08187-1905 this is the first detailed abundance analysis based upon high resolution spectra. Mild indication of s-processing for IRAS 01259+6823, IRAS 05208-2035 and IRAS 08187-1905 have been found and a more comprehensive study of s-process enhanced objects IRAS 17279-1119 and IRAS 22223+4327 have been carried out. We have also made a contemporary abundance analysis of the high galactic latitude supergiants BD+39 4926 and HD 107369. The former is heavily depleted in refractories and estimated [Zn/H] of -0.7 dex most likely gives initial metallicity of the star. For HD 107369 the abundances of alpha and Fe-peak elements are similar to those of halo objects and moderate deficiency of s-process elements is seen. IRAS 07140-2321 despite being a short period binary ...
The finest particle size fractions ({le} 25 {mu}m) in four fly ash samples from fluidised bed combustion of three biomass based fuels and a municipal solid waste fuel were size separated using a centrifugal SPLITT fractionation cell. The ashes were separated into different size fractions and the cadmium concentration, partition and speciation in each separated fraction were then investigated in relation to their possible leaching. The fractionation was evaluated by environmental scanning electron microscopy, which also provided indications of the associations between Cd and other main elements on the particles through the use of X-ray fluorescence mapping. The total concentration of Cd in each fraction was determined by AAS analysis which showed different dependence on the ash particle size in the case of biomass or waste fuels. In addition, the speciation of Cd in each fraction, investigated by sequential chemical extractions and X-ray powder ...
This report presented an analysis of incidents gathered by the Canadian upstream oil and gas industry committee in relation to explosive atmospheres in wellbores, vessels, tanks, and piping systems. The aim of the report was to develop industry recommended practices for oil and gas industry fires and explosions. Two accident theory models were used to set out the relationships between hazards, defenses, and losses. Three levels of defenses were identified based on organizational, local workplace, and human factors. An organizational responsibility approach was used to examine the activities of key people with the system. Incidents were analyzed based on an expanded fire triangle used to identify fire and explosion hazards. The study showed that the ignition of hydrocarbons into the air was a factor in nearly 50 per cent of the incidents. A lack of understanding of liquid-hydrocarbon properties was demonstrated in incidents involving oxidized hydrocarbons. A lack of ...
In this paper a computational analysis of 11 fuel samples (seven UO_2 and four MOX) with a burn-up ranging from 20 MWd/kgHM up to 121 MWd/kgHM (HM: Heavy Metal) is carried out with the depletion module of the lattice code CASMO-4E [Rhod01, Rhod01b] using the neutron data libraries ENDF/B-VI and JEF-2.2 and a pin cell model. In order to assess the accuracy of the model and the depletion calculation in the determination of the isotopic inventory after several irradiation cycles, the calculated results were compared to experimental data gathered from a chemical isotopic analysis of the fuel samples performed at the Hot Laboratory at the Paul Scherrer Institut (PSI), Switzerland. Selected results of this comparison, which includes 54 isotopes (17 actinides and 37 fission products), are presented here. (orig.)
This project was supported through ERDA to demonstrate that the temporal distribution of tritium can be documented by the analysis of bound hydrogen in annual tree-ring samples. The project focuses on two sample locations at the Savannah River Site (SRS), a nuclear material production facility located in Aiken, SC. The SRS provided samples of cross-sections from a single tree that were to be pooled together for analysis. Annual tree-rings were identified in each cross-section sample and separated for the period 1954 to 1993. These annual samples were ground and chemically treated to separate the hollocellulose fraction of the wood, then subsequently combusted and the resulting water counting using low-level liquid scintillation counting equipment. Additionally, the ground annual tree-rings were gamma-counted to determine any temporal variation in radionuclide activity and analyzed with x-ray fluorescence to find any ...
This report describes the work performed during FY 1995 by Pacific Northwest Laboratory in developing and optimizing analysis techniques for identifying organics present in Hanford waste tanks. The main focus was to provide a means for rapidly obtaining the most useful information concerning the organics present in tank waste, with minimal sample handling and with minimal waste generation. One major focus has been to optimize analytical methods for organic speciation. Select methods, such as atmospheric pressure chemical ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry, were developed to increase the speciation capabilities, while minimizing sample handling. A capillary electrophoresis method was developed to improve separation capabilities while minimizing additional waste generation. In addition, considerable emphasis has been placed on developing a rapid screening tool, based on Raman and ...
ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...
ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can meet the no-evacuation requirement under average weather conditions. We also provide ...
The identification and characterization of carbonaceous materials (CMs) that control hydrophobic organic chemical (HOC) sorption is essential to predict the fate and transport of HOCs in soils and sediments. The objectives of this paper are to determine the types of CMs that control HOC sorption in the oxidized and reduced zones of a glacially deposited groundwater sediment in central Illinois, with a special emphasis on the roles of kerogen and black carbon. After collection, the sediments were treated to obtain fractions of the sediment samples enriched in different types of CMs (e.g., humic acid, kerogen, black carbon), and selected fractions were subject to quantitative petrographic analysis. The original sediments and their enrichment fractions were evaluated for their ability to sorb trichloroethene (TCE), a common groundwater pollutant. Isotherm results and mass fractions of CM enrichments were used to calculate sorption contributions of ...
Nuclear fuel vendors in Japan are now studying reprocessed uranium (RepU) fuel in order to prepare for full scale utilization in the future. Separate studies are made for PWR and BWR fuel. The study consists of 2 phrases. The purposes of phase-1 are to understand various RepU characteristics in the fuel fabrication process, to analyze the core characteristics by loading RepU assemblies, to solve the problems clarified in the study, and to collect basic data for licensing. In phase-2, the effects of impurities on the fabrication process will be evaluated, and the safety of RepU fuel manufacturing will be confirmed with a RepU fuel fabrication campaign in 1990. The neutronic data will be collected after insertion into power reactors, and the data will be used to verify plant safety for full utilization of RepU in the future. This paper summarizes the phase-1 study results. 1. RepU Characteristics. The internal and external radiation exposures due to nuclide impurities in RepU, were ...
The nano-structured Fe(III)-doped TiO{sub 2} photocatalysts with anatase phase have been developed for the oxidation of non-biodegradable different organic dyes like methyl orange (MO), rhodamine B (RB), thymol blue (TB) and bromocresol green (BG) using UV-Hg-lamp. The different compositions of Fe{sub x}Ti{sub 1-x}O{sub 2} (x = 0.005, 0.01, 0.05, and 0.1) nanocatalysts synthesized by chemical method (CM), have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra, specific surface area (BET), transmission electronic microscopy (TEM) analysis, XPS, ESR and zeta potential. From XRD analysis, the results indicate that all the compositions of Fe(III) doped in TiO{sub 2} catalysts gives only anatase phase not rutile phase. For complete degradation of all the solutions of the dyes (MO, RB, TB, and BG), the composition with x = 0.005 is more photoactive compared all other compositions of Fe{sub x}Ti{sub ...
The object of this paper is to identify the key elements that impact a radiation dose at EAB (Exclusion Area Boundary). This study is based on the AST (Alternative Source Terms) as defined in Regulatory Guide 1.183. The LOCA (Loss of Coolant Accident) and the LRA (Locked Rotor Accident) are selected as limiting cases. A sensitivity analysis of accidental behavior with respect to various parameters during LOCA and LRA at Kori Unit 1 is also undertaken for the following objectives: to determine the limiting parameters, to find the impact trend of the radiation dose, and to find the safety margin between AST and TID (Technical Information Document) methodologies. This work confirms that key parameters are particulate removal rate, decontamination factor, iodine chemical form, gap fraction, partitioning factor, and the impact of isotopes group. Comparing TID with AST, the radiation dose of TID is about 80% greater than that of AST under a LOCA, and ...
Abstract Background: Aution Max AX-4030, a test strip analyzer recently introduced to the market, represents an upgrade of the Aution Max AX-4280 widely employed for urinalysis. This new instrument model can allocate two different test strips at the same time. In the present study the two instruments have been compared together with the usage of Uriflet 9UB and the recently produced Aution Sticks 10PA urine strips, the latter presenting an additional test area for the measurement of urinary creatinine. Methods: Imprecision and correlation between instruments and strips have been evaluated for chemical-physical parameters. Accuracy was evaluated for protein, glucose and creatinine by comparing the semi-quantitative results to those obtained by quantitative methods. The well-known interference effect of high ascorbic acid levels on urine glucose test strip determination was evaluated, ascorbic acid influence was also evaluated on protein and creatinine ...
Peer assessment provides a powerful avenue for students to receive feedback on their learning. Although student perceptions of peer assessment have been studied extensively in higher education, little qualitative research has been undertaken with medical students in problem-based learning (PBL) curricula. A qualitative study of students' attitudes to, and perceptions of, peer assessment was undertaken within the framework of a larger study of metacognition with first-year medical students at the University of Queensland. A highly structured format for provision of feedback was utilised in the study design. Many recommendations from the higher education literature on optimal implementation of peer-assessment procedures were put into practice. Results indicated the existence of six main themes: (1) increased responsibility for others, (2) improved learning, (3) lack of relevancy, (4) challenges, (5) discomfort, and (6) effects on the PBL process. ...
In the third millennium, when the main words are globalization, world net of computers, genetic code and efficiency, deep transformations have been incorporated to human behavior. Among such transformations it may be pointed out, matching with the objectives of this study, the modem consumer's profile. The consumers have quickly become more and more conscious and demanding regarding to the quality of the available products in the market. In that sense, the consumer's concern about the natural and healthy appearance, as well as the preservation of the nutritious content of the foods, have been a constant sign of alert for producers and suppliers. Besides, the timeless for domestic preparation of foods have imposed the use of minimally processed as an incontestable reality. A barrier for the production of minimally processed foods is imposed by the degree of perishability of certain products, such as the cassava-parsley. This vegetable is a source of energy, calcium, phosphorus and ...
This study assesses the current state of undergraduate instruction in empirical research methods in communication and offers recommendations for enhancing such instruction. Responses to an online questionnaire were received from 149 communication-related programs at four-year colleges and universities. Just over 85% of responding programs offered an empirical methods course. Although the course often covered both qualitative and quantitative methods, instruction was heavily slanted toward quantitative methods and topics common to both qualitative and quantitative inquiry. The empirical methods course was usually required for graduation, but it was typically not well integrated with the rest of the curriculum and taken late in students' undergraduate careers. Additional analyses examined st...
Objective: Given the increasing popularity of motorcycle riding and heightened risk of injury or death associated with being a rider, this study explored rider behavior as a determinant of rider safety and, in particular, key beliefs and motivations that influence such behavior. To enhance the effectiveness of future education and training interventions, it is important to understand riders' own views about what influences how they ride. Specifically, this study sought to identify key determinants of riders' behaviors in relation to the social context of riding, including social and identity-related influences relating to the group (group norms and group identity) as well as the self (moral/personal norm and self-identity). Method: Qualitative research was undertaken via group discussions ...
Osteoporosis is accompanied by predominantly metaphyseal fractures with a delayed and qualitatively reduced healing process. This study addressed the question of whether fracture healing in the context of osteoporosis prophylaxis is improved with estrogen (E) or alendronate (ALN). Thirty-six ovariectomized and 12 sham-operated 12-week-old rats received soy-free (osteoporotic C, sham), E-, or ALN- supplemented diets. After 10?weeks, a metaphyseal tibia osteotomy and standardized T-plate fixation were performed. After a 5-week healing process, the fracture callus was evaluated qualitatively by biomechanical bending test and quantitatively in microradiographic sections. The time course of callus formation was examined using fluorochrome-labeled histological sections. Administration of E impro...
To define the quantitative and qualitative effects of gossypol (GP) on deer (Cervus elaphus) semen, the animals were fed cottonseed (CS). Adult stags each received 350?g of CS for 109?days. Animals received 15?mg of gossypol per kilogram body weight per day. Quantitative and qualitative parameters of experimental ejaculates (n?=?182) were compared to ejaculates (n?=?571) of control animals (n?=?5) collected during three previous natural reproductive seasons. Ejaculate fractions were evaluated by classical methods used in domestic animals. In this paper, we show that mature male deer fed CS exhibited morphological changes and decreased motility of spermatozoa and abnormalities in spermatogenesis. Radioimmunoassay measured concentrations of various steroid hormones (T-testosterone, A4-andros...
The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.
The dynamical effects of spatially homogeneous electromagnetic fields on anisotropic Bianchi type-IX models are studied. The Lagrangians and Hamiltonians affecting the evolution of anisotropy (including the gravitational and electromagnetic potentials) are obtained for very general spatially homogeneous metrics by means of the Arnowitt-Deser-Misner Hamiltonian formalism. For models having diagonal metrics an exact solution for the electromagnetic fields is obtained. This solution allows a qualitative solution for the gravitational variables. The total solution is similar to that of Brill. For Bianchi type-IX models having symmetric and general metrics, a discussion of the qualitative behavior of the universe point under the influence of the above potentials is given. In particular, it is shown that in some cases the presence of the electromagnetic potential inhibits some types of singularities.
The study described in this report is part of a project sponsored by the Toronto Atmospheric Fund, performed at the Lawrence Berkeley National Laboratory, to assess the potential role of surface property modifications on energy, meteorology, and air quality in the Greater Toronto Area (GTA), Canada. Numerical models were used to establish the possible meteorological and ozone air-quality impacts of increased urban albedo and vegetative fraction, i.e., ''cool-city'' strategies that can mitigate the urban heat island (UHI), significantly reduce urban energy consumption, and improve thermal comfort, particularly during periods of hot weather in summer. Mitigation is even more important during critical heat wave periods with possible increased heat-related hospitalization and mortality. The evidence suggests that on an annual basis cool-city strategies are beneficial, and the implementation of such measures is currently being investigated in the U.S. and ...
This report describes the results made in fulfillment of contract DE-FG26-02NT15451, ''Multicomponent Seismic Analysis and Calibration to Improve Recovery from Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado''. Optimizing development of highly heterogeneous reservoirs where porosity and permeability vary in unpredictable ways due to facies variations can be challenging. An important example of this is in the algal mounds of the Lower and Upper Ismay reservoirs of the Paradox Basin in Utah and Colorado. It is nearly impossible to develop a forward predictive model to delineate regions of better reservoir development, and so enhanced recovery processes must be selected and designed based upon data that can quantitatively or qualitatively distinguish regions of good or bad reservoir permeability and porosity between existing well control. ...
This technical memorandum (TM) documents the 1995 characterization of eight underground radioactive waste tanks at Oak Ridge National Laboratory (ORNL). These tanks belong to the Gunite and Associated Tanks (GAAT) operable unit, and the characterization is part of the ongoing GAAT remedial investigation/feasibility study (RI/FS) process. This TM reports both field observations and analytical results; analytical results are also available from the Oak Ridge Environmental Information System (OREIS) data base under the project name GAAT (PROJ-NAME = GAAT). This characterization effort (Phase II) was a follow-up to the {open_quotes}Phase I{close_quotes} sampling campaign reported in Results of Fall 1994 Sampling of Gunite and Associated Tanks at the Oak Ridge National Laboratory, Oak Ridge, Tennessee, ORNL/ER/Sub/87-99053/74, June 1995. The information contained here should be used in conjunction with that in the previous TM. The sampling plan is documented in ORNL Inactive Waste Tanks ...
Systematic analysis of the energy level schemes, ground state absorption (GSA) and covalency effects for the Ni{sup 2+} ion in Ca{sub 3}Sc{sub 2}Ge{sub 3}O{sub 12} was performed. The recently developed first-principles approach to the analysis of the absorption spectra of impurity ions in crystals based on the discrete variational multi-electron method (DV-ME) [K. Ogasawara et al., Phys. Rev. B 64, 115413 (2001)] was used in the calculations. As a result, complete energy level schemes of Ni{sup 2+} and its absorption spectra at both possible crystallographic positions (distorted octahedral Sc{sup 3+} and tetrahedral Ge{sup 4+} positions) were calculated, assigned and compared with experimental data. Energies of the charge transfer (CT) transitions for both positions are estimated. Numerical contributions of all possible electron configurations into the calculated energy states were determined. By performing analysis of the ...
Focused ion beam (FIB) microscopes have become well-established in the semiconductor industry during the past decade, and are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided transmission electron microscope (TEM) specimens and as stand alone specimen preparation and imaging systems. FIB secondary electron imaging (SEI) of nickel-based alloys, such as commercially produced Alloy 600 (approximately Ni 15Cr 10Fe 0.5C), has been demonstrated to show a high degree of sensitivity to the presence of deformation in the alloy, and FIB secondary ion imaging (SII) is particularly useful for identifying the presence of grain boundary corrosion, as secondary ion yields from metallic specimens can increase by three orders of magnitude in the presence of oxygen. This 'oxygen enhanced yield', makes FIB SII ideal for detection of corrosion at grain boundaries down to thicknesses of only a few tens of nanometers. Historically, while ...
This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, ...
Comparative studies of flocculent and grand-design spirals suggest that density waves are not the predominant trigger of star formation in most galaxies. Implications for chemical evolution are profound. It may be possible to ignore the details of the spiral-wave phenomenon in research aimed at unifying the chemical properties of spiral disks. 16 references.
BackgroundA key question in the risk assessment of exposures to multiple chemicals is whether mixture effects may occur when chemicals are combined at low doses which individually...Full Text Available
Simultaneous or prior exposure to one chemical may alter the concurrent or subsequent response to another chemical, often in unexpected ways. This is particularly true when the two chemicals...Full Text Available
Environmental chemicals that function as estrogens have been suggested to be associated with an increase in disease and dysfunctions in animals and humans. To characterize chemicals that may act as...Full Text Available
An approach to generate mimics of phosphorylated serine proteins chemically through site-specific sulfonation of cysteine is presented. This chemical modification is reversible in the presence of reducing agent and therefore is analogous to the kinase/phosphatase system used in nature. PMID:21717004
The experimental data set used to evaluate site-specific histopathologic correspondence between the morphologic end points of toxicity and carcinogenicity comprises 130 chemical carcinogenesis studies....Full Text Available
The Molecular Genetics and Carcinogenesis Section conducts studies using human epithelial cells to assess: activation of proto-oncogenes by chemical and physical carcinogens; inactivation and dysregulation of tumor suppressor genes by chemical and physical
Hard Nano-Strutural Coatings Resistant to the Extreme Conditions of Chemical, Abrasive and High Energy Media for Thermonuclear Power, Oil and Gas and Chemical Industries
Immunomodulation by environmental chemical contaminants and the role immune parameters play in toxicity and risk assessment studies is of increasing concern. Although considerable evidence has indicated...Full Text Available
Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and...Full Text Available
The immune system plays a crucial role in maintaining health; however, accumulating evidence indicates that this system can be the target for immunotoxic effects caused by a variety of chemicals including...Full Text Available
... Risk (Adverse) for Endangered Species: Risk to aquatic species if anticipated pesticide residue levels equal one-fifth of LD10 or one-tenth of LC50; risk to ...terrestrial species if anticipated pesticide residue levels equal one-fifth of LC10 or one-tenth of LC50. Risk Assessment: Qualitative and quantitative evaluation of the ... Risk for Non-Endangered Species: Risk to species if anticipated pesticide residue levels are equal to or greater than LC50. Risk Management: The process ...
The dependence of Tsub(c) on composition and deformation is calculated and compared with the corresponding dependence for Tsub(m). It is shown that superconducting and structural properties of A-15 compounds can be described, at least qualitatively, by the quasi-one-dimensional model previously developed by the authors. The superconductivity mechanism is assumed to be analogous to the BCS theory. The upper critical field Hsub(c2) of the V_3Si or Nb_3Sn compounds is found to be much greater than that in V or Nb.
We discuss the Sundman-Weierstrass theorem of total collapse in its historical context. This remarkable and relatively simple result, a type of stability criterion, is at the crossroads of some interesting developments in the gravitation Newtonian N-body problem. We use it as motivation to explore the connections to such important concepts as integrability, singularities and tyipicality in order to gain some insight on the transition from a predominantly quantitative to a novel qualitative approach to dynamical problems that took place at the end of the 19th century.
The Si-L X-ray emission spectrum of amorphous hydrogenated silicon (a-Si:H) is presented and discussed. For a qualitative interpretation of the measured spectra cluster calculations of pure Si clusters (SiSi4) and Si clusters with hydrogen (SiSi3H) have been performed using a simplified LCAO-X scheme. In general the level shifts caused by introduction of hydrogen are small compared with the valence band width.
BackgroundHIV infection causes a qualitative and quantitative loss of CD4+ T cell immunity. The institution of anti-retroviral therapy (ART) restores CD4+ T...Full Text Available
Brachytherapy consists of sealed radioactive source implantation. The diversity in the nature of radioelements, in their energy and activity requires strict implantation and utilization rules. These rules include radioactive source physical parameters check, after-loading machine and treatment planning system quality assurance and safe and reproducible dosimetric systems. Patient and medical workers information guarantee radioprotection and prevention of accidental exposures. (authors)
The quark structure of constituent nucleons is considered by a qualitative comparison of features of different models with experimental data with respect to cumulative meson production. It is shown that the fluctuation of the density of nuclear matter, ie the creation and disintegration of a short lived few-nucleon correlation (flucton), is a type of the quasi-resonance formation in the nucleus which exists without any connection with the incident particle. The cumulative production in the region under investigation is mostly the result of a Regge type dissociation of the flucton. (U.K.).
In this article, the authors recall the factors apt to influence image quality in NMR Imaging and present the european works that have been developed in MRIQA to set 5 quality assurance tests: EUROSPIN 1 to 5.
This report documents the evaluation of risks associated with environmental restoration activities at Brookhaven National Laboratory using two tools supplied by DOE to provide a consistent set of risk estimates across the DOE complex: Risk Data Sheets (RDS) and Relative Risk Ranking. The tools are described, the process taken characterized, results provided and discussed. The two approaches are compared and recommendations provided for continuing improvement of the process.
This device has and head-race pipe with an external part and a coaxial inner part. A measuring head is mounted movable between these 2 parts and has at least a thermocouple and a mobile grid for varying the section and the sodium flow to facilitate the impurities dissolution. This ensemble is completed by a longitudinal body containing the main parts of the indicator and surrounded by a thermal exchanger to cool the sodium.
BackgroundSouth Africa has a high tuberculosis (TB)-human immunodeficiency virus (HIV) coinfection rate of 73%, yet only 46% of TB patients are tested for HIV. To date, relatively...Full Text Available
It is shown that both the Tsub(c) and Tsub(m) dependences on the deformations and composition for the A-15 compounds can be described at least qualitatively in the quasi-one-dimensional model developed by the authors previously. The mechanism for the superconductivity is supposed to be the same as in the BCS theory. The upper critical field near Tsub(c) is obtained. (author).
The nucleon decay of subbarrier single-particle states with large angular momentum and parity opposite to that of the shell in soft spherical nuclei is considered. It is shown that the reduced probabilities of the nucleon decay into the ground state (0{sup +}) and into the first excited (2{sup +}) state of the daughter nucleus have qualitatively different energy dependences. (orig.).
The nucleon decay of subbarrier single-particle states with large angular momentum and parity opposite to that of the shell in soft spherical nuclei is considered. It is shown that the reduced probabilities of the nucleon decay into the ground state (0"+) and into the first excited (2"+) state of the daughter nucleus have qualitatively different energy dependences. (orig.).
Nucleon decay of underbarrier one-quasiparticle states with large angular momentum in soft spherical nuclei is considered. It is shown that energy dependences of differential probabilities of nucleon decay to the ground (0"+) and first excited (2"+) states of daughter nucleus differ qualitatively from each other due to strong interaction between quasiparticles and low-lying quadrupole states.
...), The SAGE Encyclopaedia of Social Science Research Methods, London: Sage Publications. Corti, L. (2003) 'Data Archives' ...), The SAGE Encyclopaedia of Social Science Research Methods, London: Sage Publications. Corti, L. and Barker, E. ...), The SAGE Encyclopaedia of Social Science Research Methods, London: Sage Publications. Corti, L. (2003) 'Qualitative Research ...
We study the growth of colonies of the yeast Pichia membranaefaciens on agarose film. The growth conditions are controlled in a setup where nutrients are supplied through an agarose film suspended over a solution of nutrients. As the thickness of the agarose film is varied, the morphology of the front of the colony changes. The growth of the front is modeled by coupling it to a diffusive field of inhibitory metabolites. Qualitative agreement with experiments suggests that such a coupling is responsible for the observed instability of the front.
A mathematical and physical model was constructed describing the hydrodynamics of the two-phase mixture in the horizontal steam generator. The HP 9830 A desk-top calculator was used for the computations. The output variable of the solution was the level shape. A quantitative and qualitative comparison was made of the results of computations and experimental data. (author).
A qualitatively different manifestation of the Rayleigh instability is demonstrated, where, instead of the usual extended undulations and breakup of the liquid into many droplets, the instability is localized, leading to an isolated narrowing of the liquid filament. The localized instability, caused by a nonuniform curvature of the liquid domain, plays a key role in the evaporation of thin liquid films off solid surfaces.
BackgroundIntermittent preventive treatment of malaria during pregnancy (IPTp) is a key intervention in the national strategy for malaria control in Tanzania. SP, the current drug...Full Text Available
Three HQE (High Quality of the Environment) realizations are presented to illustrate the environmental quality in the architecture, and to see how the natural gas answers the demands of the HQE. (A.L.B.)
Focused ion beam (FIB) repair of chromium defects on photomasks and reticles leaves a post repair stain in the quartz substrate. The wavelength dependent absorption properties of typical stained regions have been measured, showing transition losses up to 80% in the deep uv. A simple model is in good qualitative agreement with the experimental results. (author).
For most of the history of binary star astronomy, systems have been classified largely on the basis of how they were discovered and qualitative appearance of their spectra and light curves. Present understanding of single and double star evolution has now progressed to the point where most of the classes previously identified, and some new ones, can be arranged into evolutionary sequences, depending primarily on the initial masses and separation of the component stars.
The electron structure of the A-15 compounds is studied by accounting for the Hubbard energy as the highest energy parameter. The conditions for the Cooper instability origination are obtained. The superconducting transition temperature dependence on the degree of filling the d- and p-shells of the transition and nontransition elements is determined. The relationship between the transition temperature and the energy jumpover along the chains, which allows comparison with the experiment, is established. Qualitative explanation of the Mattias empiric rules is presented
The report describes the studies carried out to design a non-destructive system for the radiological characterization of packages containing LLW and MLW. This technique is applied for quantitative and qualitative gamma emitters determination in packages with homogeneous and heterogeneous matrices as well as the development of a maximum activity points location system. Development involves also the automatization for its industrial use.
The defect-induced electron lifetime and energy-gap anisotropy effects on the T/sub c/ of the A-15 compounds are examined. A self-consistent model calculation demonstrates that the various defect dependences of T/sub c/ can be qualitatively understood in terms of the electron-lifetime effect.
The defect-induced electron lifetime and energy-gap anisotropy effects on the T/sub c/ of the A-15 compounds are examined. A self-consistent model calculation demonstrates that the various defect dependences of T/sub c/ can be qualitatively understood in terms of the electron-lifetime effect.
Two crucial properties of QCD, confinement and chiral symmetry breaking, cannot be understand within the context of conventional Feynman perturbation theory. Non-perturbative phenomena enter the theory in a fundamental way at both the classical and quantum level. Over they years a coherent qualitative picture of the interplay between chiral symmetry, quantum mechanical anomalies, and the lattice has emerged and is reviewed here.
Qualitative and quantitative techniques, including a telephone survey of 310 Taiwanese business owners, were used to study the unique features of Taiwanese immigrant businesses in Los Angeles (California). When provided with entrepreneurial capital, Taiwanese enterprises grow rapidly in the context of Los Angeles's economic restructuring. (SLD)
BackgroundIn Nigeria ACT use at the community level has not been evaluated and the use of antimalarial drugs (commonly chloroquine (CQ)) at home has been shown to be largely incorrect....Full Text Available
A unified calculation of neutron-rich isotopes in lithium is performed using the hyperspherical basis in which the underlying symmetry of each isotope exhibits a simple structure. The variation of the binding energy as a function of mass number is qualitatively reproduced, and the asymptotic of radial distribution of each isotope decreases exponentially. The form factors of the lithium isotopes are calculated and display diffraction minima. 27 refs., 3 figs., 3 tabs.
We present an abundance analysis based on high-resolution spectra of 10 stars selected to span the full range in metallicity in the Ursa Minor (UMi) dwarf spheroidal (dSph) galaxy. We find that [Fe/H] for the sample stars ranges from -1.35 to -3.10 dex. Combining our sample with previously published work for a total of 16 luminous UMi giants, we establish the trends of abundance ratios [X/Fe] as functions of [Fe/H] for 15 elements. In key cases, particularly for the #alpha#-elements, these trends resemble those for stars in the outer part of the Galactic halo, especially at the lowest metallicities probed. The neutron-capture elements show an r-process distribution over the full range of Fe metallicity reached in this dSph galaxy. This suggests that the duration of star formation in the UMi dSph was shorter than in other dSph galaxies. The derived ages for a larger sample of UMi stars with more uncertain metallicities also suggest a population dominated by ...
Sulfate attack of cement-based materials remains an important problem for the durability assessment of containers and disposal engineering barriers dedicated to the long-term storage of radioactive wastes since underground water which may reach these elements contains small quantities of sulfates (7-31 mmol/1). This work contributes to the study of sulfate-induced damage mechanisms, to their understanding and modelling. The experimental phases of this study aimed at the understanding of the different physico-chemical phenomena involved during an external sulfate attack at following their evolution and their impact on the transport and mechanical properties of the material. Leaching experiments in pure water and in a solution of sodium sulfate (with a sulfate content of 15 mmol/1), have been performed simultaneously on OPC paste (w/c 0,4)in order to allow a comparison of test results. The frequent analysis of the leachant has shown a consumption ...
The experimental work completed thus far in the areas of rapid radiochemical separations and metastable isomeric states is summarized. Activation analyses were made in samples of ore materials and metals using rapid radiochemical separations to isolate short-lived radioactive isotopes such as 3.77-min V/sup 52/ and 14.6-min Mo/sup 101/. The analytical results obtained were compared to the results obtained from standard chemical and instrumental analytical methods and, where possible, to activation analysis results obtained from longer-lived isotopes of the same element. Further work is in progress to improve the procedures, to evaluate the reproducibility and accuracy of the methods, and to evaluate their usefulness on a wide variety of sample matrices. The research on short-lived metastable isomers showed that 1.7-min W/sup 185m/ is not produced in sufficiently high yield for the development of a supplementary ...
In this work some physicochemical properties and the thermal behavior and stability of sour sop or guanabana (Annona muricata) seed almond oil were studied by means of chemical, DSC and TG analysis. The results showed that the almond has 2.5% ash, 17.9% crude fiber, 15.7% protein, 26.0% de carbohydrates and 37.7% oil (dry base). The composition of almond oil showed 68.5% unsaturated fatty acids, mainly oleic and linoleic, and some palmitoleic acids, and 31.5% saturated, principally palmitic and stearic fatty acids; refraction index was 1.468 and saponification and iodine value were 168.2 and 87.0, respectively. DSC thermal analysis showed that oil crystallization initiates at -4.5 degree centigrade and ends at -79.0 degree centigrade with a crystallization enthalpy of 48.2 J/g; the oil melts in a temperature range from -42.4 to -16.9 degree centigrade, with a maximum peak at -15 degree centigrade and a fusion enthalpy of ...
Previous in vitro studies have demonstrated that Ho:YLF laser is capable of inducing physical and chemical changes on dental surfaces treated for caries prevention. The temperature in the pulp chamber was in vitro evaluated to as a function of the power and frequency of the laser irradiation. The purpose of this work is to verify the occurrence of pulp inflammation after Ho:YLF laser irradiation using different parameters in rabbits' teeth. The premolars and molars of ten rabbits (NZB) were divided in two groups according to the irradiation energy values of a Ho:YLF laser prototype operating at 2.065{mu}m wave length, frequency of O,5Hz and pulse length of 250{mu}s. An group A teeth were irradiated with using ten pulses of 334mJ/pulse of a Ho:YLF laser prototype operating at O.5Hz, and group B, with 512mJ/pulse. Animals were killed by transcardiac perfusion and the samples were prepared for histopathological analysis. The in vitro ...
Medetomidine and fentanyl-droperidol (Innovar-vet) were assessed over a three hour period in 80 healthy dogs. Following physical examination, electrocardiogram (ECG), arterial blood sample analysis, and dynamometer pressure threshold (analgesia score), the dogs were randomly assigned to one of four treatments: Miv--medetomidine (750 micrograms/M2) administered intravenously (IV), Mim--medetomidine (1000 micrograms/M2) administered intramuscularly (IM), Iiv--Innovar-vet IV (0.05 mL/kg) or Iim--Innovar-vet IM (0.1 mL/kg). All assessments were carried out by a single individual unaware of the treatment used. Objective assessments included temperature, heart and respiratory rates, analgesia score, arterial blood gases, acid-base and lactate levels. Subjective evaluation included degree of sedation, response to various clinical procedures, noise responsiveness, posture, and the incidence of side effects. Onset and duration of effect were also recorded. The ECG strips ...
Liquid sodium is used as coolant in Fast Breeder Reactors (FBR). There is a likelyhood of sodium spillage in ambient air in the Steam Generator Building (SGB) of the FBR plant. Due to high chemical reactivity with oxygen, especially at temperatures greater than 573 K, it catches fire very easily. In order to carryout safety related experimental studies for different modes of sodium fires and to develop suitable mathematical models for the assessment of their consequences, an experimental facility (SFEF, Sodium Fire Experimental Facility) is being setup a IGCAR, Kalpakkam. The SFEF is having a 540 m"3 volume experimental hall. Stainless steel linear will be provided on the inside surfaces of experimental hall walls, ceiling and floor. Analysis has been carried out for enclosed sodium pool fire scenarios in SFEF by using sodium pool fire code SOFIRE II, which estimates the thermal transients like pressure rise, gas temperature rise, cell wall ...
A gel-type "9"9Mo-"9"9"mTc generator using Titanium-Molybdate target (TiMo-target) as column packing was developed in Radioisotope Department, the Dalat Nuclear Research Institute [1]. The concentration of trace elements in TiMo-target and radionuclidic purity in "9"9"mTc solution eluted from this type of generator were studied for quality control purpose. The monostandard method in neutron activation analysis has been applied to determine the concentration of trace impurities in titanium-molybdate target. For neutron activation analysis, TiMo samples were irradiated in the different channels of nuclear reactor IVV-9 at a neutron flux of maximum 2.1 x 10"1"3 n.cm"-"2s"-"1. The following chemical element impurities were determined: Na, W, Co, Fe, Zn, Ag, Sb and Cr. The gamma ray emitted nuclides found in "9"9"mTc solution eluted from our "9"9"mTc generator were the following: "6"5Zn, "6"0Co, "1"1"0"mAg, "5"9Fe, "5"1Cr, ...
Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there are substantial problems with the experimental technique employed that, they contend, lead to completely erroneous conclusions. In the more recent of their two papers Prange et al. employed a curve-fitting method similar to that used by us (for more than 10 years). In essence, the method employs simply fitting a linear combination of the spectra of standard compounds to that of the unknown, in this case cultures of bacterial cells. This type of analysis can provide quantitative estimates of the individual sulfur types in the sample, ...
One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O]"+"3 precursor. Following this ''mixed ligand'' concept, a novel "9"9"mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using "9"9"mTc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. The Re complex was also prepared by substitution method and ...
We summarize the results of point-contact Andreev-reflection (PCAR) spectroscopy in MgB{sub 2} doped by chemical substitutions, either magnetic (Mn) or non-magnetic (Al,C), obtained by us and by other groups in the last four years. Despite the variety of samples used (crystals and polycrystals of various origin) and some minor differences in the experimental techniques, these measurements have directly provided a complete and consistent picture of the effects of chemical substitutions on the gaps of MgB{sub 2} shedding light on other relevant parameters (scattering rates, DOSs) affected by doping. In Al-doped crystals and polycrystals, the gap amplitudes {delta}{sub {sigma}} and {delta}{sub {pi}} - obtained through a two-band Blonder-Tinkham-Klapwijk (BTK) fit of the Andreev-reflection conductance curves - decrease on increasing the Al content x (i.e. on decreasing the critical temperature of the contacts T{sub c}{sup A}), but remain clearly ...
This paper deals with an analysis of a single specimen of Tentaculites crotalinus SALTER emend. CIGUEL et al. (1984) that present a possible partial preservation of the shell. It comes from an outcrop of the Grossa Formation (Devonian) near Jaguariaiva, State of Parana. The skeletal microstructure of the Tentaculitoidea shell rather poorly Known. Thus, the phylogenetic relationships of these invertebrates still uncertain. Tentaculitids are very common fossils in Devonian Ponta Grossa Formation (Parana Basin) but so far Known only from external and internal moulds. The objective of this study is to demonstrate wheter the layer found in between the internal and external mould is or not a case shell preservation. The chemical composition of this layer and of the external mould was analysed by X rays. X rays difratometry was applied only to the matrix (at the external mould). The structure of the supposed shell remain was studied by binocular ...
As stated last quarter, we discovered potassium as an impurity in the mixed metal oxides. The potassium was probably incorporated into the solid during the coprecipitation using K{sub 2}CO{sub 3}. Currently NH{sub 4}OH is being used as the precipitating base. We have discovered that the precipitation agent influences the surface composition of the mixed-metal oxides. Chemicalanalysis of the surface and bulk compositions showed significant differences in surface compositions of the K{sub 2}CO{sub 3} and NH{sub 4}OH precipitated catalysts. In TPR experiments we have discovered that the precipitating pH markedly affects the reducibility of the ZnMnCr oxides. This shows that the choice of base as well as the pH strongly affects the surface composition of the mixed metal catalysts. Additional studies are in progress in which we are studying how the precipitating agents affect the surface composition of the mixed metal oxide catalysts and how the ...
Cassava is cultivated almost all over the world and it is considered one of the most important nutritious sources of calories in the human diet. Cassava is a viable food against starvation in several poor areas of the world because it is an extremely resistant culture and may reach satisfactory economical yield. We utilized vacuum packed industrialized cassava irradiated with 0,1 kGy, 3kGy and 5kGy and stored under refrigeration for 1, 21, 30 and 50 days. Our objective was to analyse the synergistic effect of vacuum packing, irradiation and refrigeration on the preservation of minimally processed cassava. The samples were analyzed for pH, acidity, weight, humidity, texture and color. The irradiation did not affect the chemical characteristics of the cassava. Neither the pH nor the acidity, the most relevant variables to verify deterioration in cassava, presented significant alterations during the period of storage. Comparing the irradiated treatments, the dose of ...
Aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), a sterically hindered amine, was examined as a potential CO{sub 2} absorbent and compared with the most commonly used absorbent, monoethanolamine (MEA) solution, through equilibrium solubility measurements and {sup 13}C NMR spectroscopic analyses. The solubilities of CO{sub 2} in aqueous 10 mass % AHPD solutions were higher than those in aqueous 10 mass% MEA solutions above 4 kPa at 298.15 K, but lower below 4 kPa. The solubility difference between these two solutions increased with the CO{sub 2} partial pressures above the crossover pressure. Equilibrated CO{sub 2}-MEA-H{sub 2}O and CO{sub 2}-AHPD-H{sub 2} solutions at various CO{sub 2} partial pressures ranging from 0.01 to 3000 kPa were analyzed by {sup 13}C NMR spectroscopy. AHPD contains more hydroxyl groups than nonhindered MEA, and hence the chemical shifts in its {sup 13}C NMR spectra were strongly influenced by the solution pH values. In ...
Richmond Harbor is on the eastern shoreline of central San Francisco Bay and its access channels and several of the shipping berths are no longer wide or deep enough to accommodate modem deeper-draft vessels. The Water Resources Development Act of 1986 (PL99-662) authorized the US Army Corps of Engineers (USACE), San Francisco District to deepen and widen the navigation channels in Richmond Harbor. Several options for disposal of the material from this dredging project are under consideration by USACE: disposal within San Francisco Bay, at open-ocean disposal sites, or at uplands disposal sites. Purpose of this study was to conduct comprehensive evaluations, including chemical, biological, and bioaccumulation testing of sediments in selected areas of Richmond Harbor. This information was required by the Environmental Protection Agency (EPA) and USACE. Battelle/Marine Sciences Laboratory collected 20 core samples, both 4-in. and 12-in., to a project depth of -40 ft ...
Effective commercial liquid absorption technology currently applicable for CO{sub 2} capture from power plant flue gases uses a conventional chemical solvent, MEA(monoethanolamine), which was developed over 60 years ago as general non selective solvent to remove acid gases from natural gas streams. The application to CO{sub 2} capture from almost atmospheric pressure flue gases required modification of the technology on account of the oxygen content to incorporate inhibitors to resist solvent degradation and equipment corrosion, as well as upstream treatment of the flue gases to remove both SO{sub x} and NO{sub x} present. The solvent strength used by such processes is relatively low in comparison with high strength modern chemical solvents. The resultant effect is large equipment and high regeneration energy requirements which is a parasitic load on the power plant. Using current technology for CO{sub 2} capture from flue gas derived from ...
Chemical looping combustion (CLC) of simulated coal-derived synthesis gas was conducted with NiO oxygen carriers supported on SiO2, ZrO2, TiO2, and sepiolite. The effect of H2S on the performance of these samples for the CLC process was also evaluated. Five-cycle thermogravimetric analysis (TGA) tests at 800 C indicated that all oxygen carriers had a stable performance at 800 C, except NiO/SiO2. Full reduction/oxidation reactions of the oxygen carrier were obtained during the five-cycle test. It was found that support had a significant effect on reaction performance of NiO both in reduction and oxidation rates. The reduction reaction was significantly faster than the oxidation reaction for all oxygen carriers, while the oxidation reaction is fairly slow due to oxygen diffusion on NiO layers. The reaction profile was greatly affected by the presence of H2S, but there was no effect on the capacity due to the presence of H2S in synthesis gas. The ...
CuO/bentonite and CuO-BHA nanocomposites were studied as oxygen carriers in chemical-looping combustion (CLC) of simulated synthesis gas. Global reaction rates of reduction and oxidation, as the function of reaction conversion, were calculated from 10-cycle oxidation/reduction tests utilizing thermogravimetric analysis at atmospheric pressure between 700 and 900{degree}C. It was found that the reduction reactions are always faster than oxidation reactions; reaction temperature and particle size do not significantly affect the reaction performance of CuO/bentonite. Multicycle CLC tests conducted in a high-pressure flow reactor showed stable reactivity for production of CO{sub 2} from fuel gas at 800 and 900{degree}C and full consumption of hydrogen during the reaction. Results of the tapered element oscillating microbalance showed a negative effect of pressure on the global rates of reduction-oxidation reactions at higher fractional conversions. ...
The relative potencies of 20 polychlorinated biphenyls (PCBs) were studied in a chicken embryo hepatocyte system. The 20 congeners were selected according to a full 2{sup 4}-factorial design based on the principal properties of all 154 tetra- through heptachlorinated PCBs. The principal properties were obtained using principal component analysis (PCA) on a multitude of different physico-chemical properties of the PCBs. Toxic equivalency factors (TEFs) were determined for seven out of the twenty PCB congeners, viz. PCB{number_sign}41, PCB{number_sign}60, PCB{number_sign}78, PCB{number_sign}126, PCB{number_sign}169, PCB{number_sign}190, and PCB{number_sign}193, which elicit measurable catalytic ethoxyresorufin-O-deethylase (EROD) activity in the chicken hepatocytes. A multivariate quantitative structure-activity relationship (QSAR) was developed by using partial least-squares to latent variables (PLS) in order to model the relationship between ...
A newly synthesized glycine derivative (termed GlyD), 2-(4-(dimethylamino)benzylamino)acetic acid hydrochloride, was used to inhibit uniform and pitting corrosion processes of Al in 0.50 M KSCN solutions (pH 6.8) at 25 "oC. For uniform corrosion inhibition study, Tafel extrapolation, linear polarization resistance and impedance methods were used, complemented with SEM examinations. An independent method of chemicalanalysis, namely ICP-AES (inductively coupled plasma atomic emission spectrometry) was also used to test validity of corrosion rate measured by Tafel extrapolation method. GlyD inhibited uniform corrosion, even at low concentrations, reaching a value of inhibition efficiency up to 97% at a concentration of 5 x 10"-"3 M. Results obtained from the different corrosion evaluation techniques were in good agreement. This new synthesized glycine derivative was also used to control pit nucleation and growth on the pitted Al surface based on ...