This Guideline provides a set of procedures for the measurement of organic contaminants and particles in producer gases from biomass gasifiers. The procedures are designed to cover different gasifier types (updraft or downdraft fixed bed or fluidised bed gasifiers), operating conditions (0 - 900C and 0.6-60 bars) and concentration ranges (1 mg/m{sub n}{sup 3} to 300 g/m{sub n}{sup 3}). The Guideline describes a modular sampling train, and a set of procedures, which include: planning and preparation of the sampling, sampling and post-sampling, analysis, calculations, error analysis and reporting. The modular sampling train consists of 4 modules. Module 1 is a preconditioning module for isokinetic sampling and gas cooling. Module 2 is a particle collection module including a heated filter. Module 3 is a tar collection module with a gas quench ...
... Title : Military Working Dog Procurements. ... Our primary objective was to determine whether recent procurements of military working dogs by the ...
The Procurement and Assistance Data System (PADS) provides a mechanism for collecting, assembling, organizing, and presenting acquisition and assistance data for the Department of Energy (DOE). This handbook and associated documents establish a uniform system to report acquisition/assistance data to PADS for the collection, processing, and dissemination of official statistical data on the Department's acquisition and assistance actions. The data provides, based on information available at the time of request, a basis for any recurring and special reports to the senior procurement executive, Congress, General Accounting Office (GAO), Federal executive agencies, Office of Management and Budget (OMB), and the general public. PADS is also used to satisfy DOE's statutory reporting requirements to the Office of Management Budget, Congress, and other Federal agencies. Accurate and timely collection of PR data is a key element in this ...
The Devonian oil shales of the Eastern United States are a significant domestic energy resource. The overall objective of the multi-year program, initiated in October 1987 by the US Department of Energy is to perform the research necessary to develop the Pressurized Fluidized-Bed Hydroretorting (PFH) process for producing oil from Eastern oil shales. The program also incorporates research on technologies in areas such as raw shale preparation, beneficiation, product separation, and waste disposal that have the potential of improving the economics and/or environmental acceptability of recovering oil from oil shales using the PFH process. The results of the original 3-year program, which was concluded in May 1991, have been summarized in a four-volume final report published by IGT. DOE subsequently approved a 1-year extension to the program to further develop the PFH process specifically for application to beneficiated shale as feedstock. Studies have shown that ...
The Devonian oil shales of the Eastern United States are a significant domestic energy resource. The overall objective of the multi-year program, initiated in October 1987 by the US Department of Energy is to perform the research necessary to develop the Pressurized Fluidized-Bed Hydroretorting (PFH) process for producing oil from Eastern oil shales. The program also incorporates research on technologies in areas such as raw shale preparation, beneficiation, product separation, and waste disposal that have the potential of improving the economics and/or environmental acceptability of recovering oil from oil shales using the PFH process. The results of the original 3-year program, which was concluded in May 1991, have been summarized in a four-volume final report published by IGT. DOE subsequently approved a 1-year extension to the program to further develop the PFH process specifically for application to beneficiated shale as feedstock. Studies have shown that ...
... POVs) overseas when space was available. ... information management system launched in 2004. ... Personally Procured Transportation (PPT) system ...
The Large Hadron Collider (LHC) project, approved by the CERN Council in December 1994, has now fully entered its construction phase, with the detailed technical definition of the major systems, and the adjudication of a number of large procurement contracts. We first recall the main features and characteristics of the LHC, report on the advances in definition of the layout and optics as well as on preparation of the injector complex, and review recent progress in the key technical systems of the main ring: magnets, cryogenics and vacuum, as well as civil construction, which has started following acceptance by authorities in the Host States.
We operate a new NEC 250kV single-stage accelerator mass spectrometer (SSAMS) next to our established 5MV tandem. This permits good comparison of 14C-AMS and challenges SSAMS performance. Initial SSAMS ion-optical deficiencies have been addressed by shimming the injection magnet and 3permil 14C/13C measurement with background limited by sample chemistry is routine. Higher-precision analysis is also achievable. A problematic measurement interference remains, however. The small spectrometer was procured to add measurement capacity, and for experiments with positive ions, but is now the preferred instrument for both convenience and measurement quality.
Our primary objective was to determine whether recent procurements of military working dogs by the 341st Training Squadron complied with section 10a, title 41, United States Code (41 U.S.C. 10a commonly known as the Buy American Act) and other procurement...
The paper presents some aspects relating to the importance of a good communication and cooperation between all factors involved in procurement process at Societatea Nationala 'Nuclearelectrica', SNN. In order to comply with the internal and international rules related to safety in nuclear field and public procurement requirements and for maintaining a high standard of operational performance of Cernavoda NPP, adequate procurement systems were developed by SNN SA. The importance of human factor and the training activities for all personnel from this chain of procurement process is the main key issue to maintain high quality of their activities considering that procurement documents are reviewed and approved before to be issued by all departments involved in procurement process. The specialized department for public acquisition is supervising that the ...
The `Procurement Quality Function` is an element of the Body of Knowledge of Quality Engineering, as defined by the American Society for Quality Control (ASQC). This paper describes the Procurement Quality function which has been installed as an integral part of the Quality Engineering group of the Technical and Management Support Services (T&MSS) contractor to the United States Department of Energy (DOE) Yucca Mountain Site Characterization Project. Each of the elements of the T&MSS Procurement Quality Engineering (PQE) system is discussed along with the measurements obtained. With the installation and development of the PQE system we have attained more meaningful evaluation of supplier capability, reduction of procurement document review reject ratios from 31% to less than 2% per quarter, more effective measurement and control of supplier performance, and the ability to enter into a meaningful ...
Examples are given of reference materials for radionuclide X-ray fluorescence analysis (RXFA) of the environment processed by the National Bureau of Standards and the IAEA. Methods are described used for preparing standard materials for RXFA. For determining air pollutants the sample is prepared by dry or wet mineralization. Water samples have to be preserved prior to analysis. Insoluble components are separated by filtration or centrifugation. Biological materials must be dehydrated and homogenized. Samples of soil, sludges, sediments and solid wastes will sometimes have to be converted into a solution in some cases a leachate will have to be obtained. (ES).
Under the auspices of the DOE and private industry, considerable progress has been made in: preparation of coal-water fuels; combustion of low-ash coal-based fuel forms; processes to provide deeply-cleaned coal. Developments in advanced beneficiation of coal to meet stringent requirements for low ash and low sulfur can be anticipated to further complicate the problem areas associated with this product. This is attributable to the beneficiated coal being procured in very fine particles with high surface areas, modified surface characteristics, reduced particle size distribution range, and high inherent moisture. Experience in the storage, handling, and transport of highly beneficiated coal has been limited. This is understandable, as quantities of such product are only now becoming available in meaningful quantities. During this reporting period the authors have: developed a suite of empirical tests covering water retention, rewetting, mull ...
This standard describes requirements and provides guidelines for the control of activities to be exercised during procurement of items and services which affect the quality of nuclear power plants. These requirements and guidelines apply to procurement activities for items and services such as designing, purchasing, fabricating, handling, shipping, storage, cleaning, constructing, erecting, installing, inspecting, testing, maintaining, repairing, initial fueling, refueling, and modifying.
Requirements and guidelines are provided for the control of activities to be exercised during procurement of items and services which affect the quality of nuclear facilities. These requirements and guidelines apply to procurement activities for items and services such as designing, purchasing, fabricating, handling, shipping, storing, cleaning, constructing, erecting, installing, inspecting, texting, maintaining and modifying.
This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.
Focus Ion Beam (FIB) milling has greatly extended the utility of atom probe and TEM because it enables samplepreparation with a level of dimensional control never before possible. Using FIB it is possible to extract the samples from desired and very specific locations. The artifacts associated with this samplepreparation method must also be fully understood. In this work issues specifically relevant to the FIB milling of aluminum alloys are presented. After using the FIB as a samplepreparation technique it is evident that gallium will concentrate in three areas of the sample: on the surface, on grain boundaries and at interphase boundaries. This work also shows that low energy Ar ion nanomilling is potentially quite effective for removing gallium implantation layers and gallium from the internal surfaces of aluminum ...
Methods of sample treatment in XRF analysis of hair are studied in view of the effect on analytical results. A new method is proposed based on the incomplete ashing of hair followed by pellet preparation. Its suitability is estimated on the XRF analysis of real hair samples collected from 4 healthy adults. (author) 12 refs.; 4 figs.; 1 tab.
The composition and thickness of etch residues on the base of submicrometer via holes cannot be surmized from data on larger features. Auger sputter depth profiles were used to compare etch residues in 0.55 {mu}m via holes produced by different etch processes and remaining after different cleans. These residues varied significantly in composition and thickness with the processing history of the sample and from those on larger features. A focused ion beam (FIB) samplepreparation was developed to expose the bases of via holes and to help reduce sample charging. (author).
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 samplepreparation are also presented.
We present a novel preparation method for studies of in vitro reconstituted mitotic chromosomes from Xenopus laevis egg extracts. This method involves a gentle adsorption of chromosomes from the extracts using surface affinity enrichment, followed by plunge freezing, freeze-substitution and cryo-embedding before examination by EM tomography. For comparison, chromosomes were also prepared by a conventional method, which included immobilization of chromosomes in agarose and a room-temperature dehydration (embedding) protocol. Three-dimensional reconstructions showed that samplesprepared with the new method have a greater interconnectivity of sub-structural features and a higher compaction ratio together with an apparently less perturbed chromatin structure than those prepared using the conventional approach. The implications of the new method for the preparation ...
A dense silica glass was prepared by consolidating a highly dispersed silicic acid powder (particle size 1H magic-angle spinning (MAS) NMR confirmed an increase in hydroxyl groups in the sampleprepared by SPS relative to that of the conventional SiO2 reference glass. Aside from the comparably high water content, we conclude from the similarity of the IR-reflectance and the 29Si MAS NMR spectra of the SPS sample and the corresponding spectra of the conventionally prepared silica glass, that the short- and medium-range order is virtually the same in both materials. Raman spectroscopy, however, suggests that the number of three- and four-membered rings is significantly smaller in the SPS sample compared to the conventionally preparedsample. Based on these results we conclude that it is possible to ...
... the program manager plans to spend $23.2 million to procure 107 Hornets in excess of the 270 required by the 82nd Airborne Division for its basic ...
International Thermonuclear Experimental Reactor (ITER) project is the international collaboration one for the commercialization of nuclear fusion energy through the technical and engineering verification. In ITER project, we plan to procure the blanket systems which has the risk of technology and cost when it is newly developed. We are developing the manufacturing process and joining technology for the ITER blanket to complete the procurement with qualified blanket system. To evaluate the soundness of manufacturing process, specimen and mock-up tests are being prepared. Finally, we can obtain the key technology of nuclear fusion reactor especially on the blanket design, joining and manufacturing technology through the present project and these technologies will help the construction of Korea fusion DEMO reactor and the development of commercial nuclear fusion reactor in Korea. In 1st year, through the fabrication of the ...
Characterization of high temperature superconducting film and bulk samples has been carried out using 2 MeV [alpha]-particle Rutherford backscattering, 2.4 MeV proton elastic scattering, 2.4 MeV proton-induced x-ray emission, 9 MeV proton induced [gamma]-ray emission and 100 MeV iodine elastic recoil detection analysis techniques. The objective was to compare different ion beam based techniques for: (i) compositional analysis; and (ii) consistency of the results obtained for samplesprepared using similar preparation methodology. (author).
New standardization techniques of samples in multielement instrumental neutron-activation analysis (INAA) of biological materials (BM) are considered. New methodical developments of samplepreparation techniques, BM tableting, creation of comparison standards and standardization of packing material are suggested. Correlated data on concentration of different elements in standard specimens-comparison standards are presented for mass INAA, that is: for phenol-formaldehyde resin-base and human blood-base synthetic standards. 7 refs.; 3 tabs.
CNPT-3 is the laboratory designation of a strain of bacteria that reproduces best at deep-sea pressures. It was isolated from a sample collected at a 5800 m depth of the Pacific Ocean. This isolation was achieved from a sample that had been retrieved without warning. This year we demonstrated that there are similarly behaving bacteria that can be isolated from samples even when retrieved with decompression. The purpose of this project was to define the temperatures and pressures over which CNPT-3 can exist and function. (1) At 2"0C CNPT-3 is eurybathic from about 1000 to 6500 m, as judged from an only slightly pressure dependent generation time. (2) CNPT-3 is unquestionably barophilic at 2"0C, with doubling times of 9 hours at 580 bars and over 18 hours at 1 bar. (3) At 10"0C, reproduction is adversely affected at 1 bar to the extent that CNPT-3 becomes obligately barophilic at 10"0C. Yet reproduction is enhanced above 280 ...
The Fast Flux Test Facility (FFTF) bottom-loading transfer cask (BLTC) system is designed to provide ex-vessel fuel transfers of irradiated reactor components between the reactor containment building and the LMFBR shipping cask in the reactor service building. This system is being procured from National Lead Industries, Wilmington, Delaware, under management of Aerojet Manufacturing Company.
In the Netherlands, the interest in biomass for electricity generation has increased, mainly due to environmental reasons. Currently, the Dutch energy sector is investigating technologies which can reduce CO{sub 2} emissions. The growth of biomass and its subsequent utilization for energy purposes circulates recycled atmospheric carbon and has no net discharge of CO{sub 2}. To reduce emissions from coal-fired power plants biomass co-firing options are investigated. After exhaustion of internal supplies of wood wastes and other residues an extra amount of 1.02 Mt{sub 20} would be needed. Two supply options exist: the use of internal energy crops and the import of biomass. Because production of energy crops in the Netherlands is a rather expensive option, biomass procurement and production outside the Netherlands is studied. Two countries were investigated for the possible import of biomass: Estonia and Uruguay. Estonia has short-term opportunities for residue supply ...
We have prepared high-quality, single crystals of SmB_6 under various conditions to improve sample quality. We have measured the resistivity and magnetic susceptibility from room to liquid-helium temperatures to sort samples. We have applied pulsed magnetic fields as high as 50 T at temperatures as low as 40 mK while measuring resistivity. Our samples are of higher quality than previously known. All solvent-grown, single-crystal samples should be etched to remove a surface conductivity. (orig.).
The iodinated oil lipiodol is commonly used as a carrier for in situ delivery of drugs or radioactivity to hepatic tumors. Recently, we reported a new kit formulation for high-activity labeling of lipiodol with the {beta}-emitting radionuclide Re-188. Since the whole preparation involves different steps and complex manipulations of high-activity samples, we describe here an automated synthesis module that allows the easy preparation of sterile and pyrogen-free samples of Re-188 lipiodol ready to be administered to the patient. Important advantages include the possibility to incorporate high Re-188 activity into the lipiodol hydrophobic phase and a sharp reduction of radiation exposure of the operator assisting the labelling procedure. Application of this modular reaction system could be also extended to the preparation of other Re-188 radiopharmaceuticals and to compound labelled ...
Microanalytical methods suitable for the determination of Fe, Cu in HT-29 (human colon adenocarcinoma) cells treated with different iron compounds (Fe(II) sulfate, Fe(III) chloride, Fe(III) citrate and Fe(III) transferrin) and cultured in medium supplemented or not with 10% (v/v) fetal calf serum (FCS) by total reflection X-ray fluorescence spectrometry (TXRF) and simultaneous graphite furnace atomic absorption spectrometry (GF-AAS) were developed. The developed TXRF method was also suitable for Zn determination in the samples. The main advantage of the proposed methods is the execution of all samplepreparation steps following incubation and prior to the elemental analysis in the same Eppendorf tubes. Samplepreparation was performed at microscale (115mL sample volume) with 65% nitric aci...
Abstract In the work, a rapid, simple and high-throughput samplepreparation method was developed for the determination of sulfonamide (SA) antibiotic residues in chicken breast muscle. The extraction and clean-up were online combined and up to 20 samples can be treated simultaneously in 6-min. The SAs were first extracted with acetonitrile under the action of microwave energy, and then the extract was directly introduced into the SPE column for on-line clean-up and concentration. Subsequently, the SAs eluted from the SPE column were determined by liquid chromatography-tandem mass spectrometry. The precisions of extraction results of 20 samples were in the range of 4.9-7.4%. The limits of detection and quantification obtained were in the range of 2.4-3.6-ng/g and 8.6-11.3-ng/g for SAs, res...
For each sample, one 30-gallon drum containing approximately 90 lb of coal at {minus}1/4 inch was designated for headspace oxygen analysis and coal quality monitoring at yearly intervals. Headspace oxygen analysis and retrieval of a 5-lb sample for coal analysis have begun. Headspace oxygen contents are shown in Table 1. Preparation and analysis of these samples for the second yearly quality evaluation is in progress. We have initiated a study of different means of storage in preventing sample deterioration and in maintaining an inert headspace atmosphere. The work was performed with support from the Penn State Cooperative Program in Coal Research. A run-of-mine sample of medium-volatile bituminous Lower Kittanning coal was collected as PSOC-1536 and promptly processed. Gieseler fluidity FSI, alkali extraction and preparation of petrographic ...
UV, first, second and third derivative spectrophotometric methods have been developed for the determination of ezetimibe in pharmaceutical formulation. The solutions of standard and sample were prepared...Full Text Available
The variation in the superconducting properties of various binary alloys of transition metal-germanium systems was surveyed by studying sputter deposited samplesprepared under various conditions. The primary interest has been to study the formation of the stoichiometric A-15 compounds T_3Ge.
High resolution structural elucidation of macromolecular structure by solid-state nuclear magnetic resonance requires the preparation of uniformly aligned samples that are isotopically labeled. In...Full Text Available
Optimal sample handling techniques for tissue preparation and storage, RNA extraction and quantification, and target gene detection are crucial for reliable gene expression analysis. Methods...Full Text Available
Low molecular weight epoxy resin based on diglycidyl ether of bisphenol A was synthesized and mixed at constant percentages with natural rubber. The rubber epoxy system was cured with various types of curing agents such as ethylene diamine, maleic anhydride as well as the prepared resole phenol formaldehyde. A study of the photo-induced crosslinking of the prepared elastic adhesives and film samples was carried out by exposure to ultraviolet lamp (300 w) for 2 weeks at 20 deg. C. Samples containing ethylene diamine were cured at 25 + - 1 deg. C. for 24 h while samples containing maleic anhydride or resole phenol formaldehyde resins were thermally cured at 150-170 deg. C. for 10 min. Cured adhesive compositions were tested mechanically and physically and evaluated as wood adhesives. While hardness, chemical resistance as well as heat stability of the prepared ...
Polymerizing effects of high energy radiation has been found suitable for preparation of wood-polymer composites. In the present work after evaluating polymer products that have been obtained by irradiation method, wood-polymer composites have been prepared by in situ polymerization of vinyl acetate, acrylic acid and acrylic acid/styrene mixture using two samples of Iranian hardwoods, Beech and Hornbeam. These woods and their composites have been tested for their physical and mechanical properties. The results have shown that chemical bonding between polymer and the cell wall component lead to better strength properties in the composites. (author).
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 (samplepreparation 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.
The purpose of this prospective study was to compare two different milk preparation methods to assay for the presence of Mycobacterium bovis by PCR. Detection by a C18-carboxypropylbetaine...Full Text Available
In January 2001, Husky Oil Operations Limited (Husky), in joint-venture with Petro-Canada, submitted a Benefits Plan for the White Rose Development to the Canada-Newfoundland and Labrador Offshore Petroleum Board (C-NLOPB). It was prepared following the Canada-Newfoundland and Labrador Atlantic Accord Implementation Act and the Canada-Newfoundland and Labrador Atlantic Accord Implementation (Newfoundland) Act. In December 2001, the C-NLOPB approved the White Rose Benefits Plan. This document described the work that Husky proposes to undertake within its significant discovery license areas 1043 and 1044 for the development of the South White Rose Extension (SWRX) Tie-back to the White Rose Floating Production, Storage and Offloading (FPSO) vessel as it will require an amendment to the original White Rose Development Plan and is subject to the review and approval of the C-NLOPB. The statutory requirements as well as the actual policies and procedures were identified ...
The DOE-Idaho Operations Office (DOE-ID) has prepared an environmental assessment (EA) on the replacement of the Idaho National Engineering Laboratory Health Physics Instrumentation Laboratory at the Idaho National Engineering Laboratory (INEL). The purpose of this project is to replace the existing Health Physics Instrumentation Laboratory (HPIL) with a new facility to provide a safe environment for maintaining and calibrating radiation detection instruments used at the Idaho National Engineering Laboratory. The existing HPIL facility provides portable health physics monitoring instrumentation and direct reading dosimetry procurement, maintenance and calibration of radiation detection instruments, and research and development support-services to the INEL and others. However, the existing facility was not originally designed for laboratory activities and does not provide an adequate, safe environment for calibration activities. The EA examined ...
This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the proposed anode design are presented. ...
This fourteenth quarterly technical progress report of the MHD Integrated Topping Cycle Project presents the accomplishments during the period November 1, 1990 to January 31, 1991. Testing of the High Pressure Cooling Subsystem electrical isolator was completed. The PEEK material successfully passed the high temperature, high pressure duration tests (50 hours). The Combustion Subsystem drawings were CADAM released. The procurement process is in progress. An equipment specification and RFP were prepared for the new Low Pressure Cooling System (LPCS) and released for quotation. Work has been conducted on confirmation tests leading to final gas-side designs and studies to assist in channel fabrication.The final cathode gas-side design and the proposed gas-side designs of the anode and sidewall are presented. Anode confirmation tests and related analyses of anode wear mechanisms used in the selection of the proposed anode design are presented. ...
A series of sputtered tungsten-carbon multilayer structures with periods ranging from 2 to 12 nm in the as-prepared state and after annealing at 500 degrees C for 4 hours has been studied with high resolution transmission electron microscopy. The evolution with annealing of the microstructure of these multilayers depends on their period.As-prepared structures appear predominantly amorphous from TEM imaging and diffraction. Annealing results in crystallization of the W-rich layers into WC in the larger period samples, and less complete or no crystallization in the smaller period samples. X-ray scattering reveals that annealing expands the period in a systematic way. The layers remain remarkably well-defined after annealing under these conditions.
The adsorption properties of four samples of the #alpha#-modification of boron nitride (#alpha#-BN) were investigated by the gas-chromatographic method. According to the electron microscopy data, the #alpha#-BN particles possess the shape of thin plates. An #alpha#-BN sampleprepared from magnesium polyboride, is the most uniform adsorbent. For a series of n-alkanes, benzene, and alkyl benzenes, by testing the #alpha#-BN samples one has obtained the retained volumes (Henry constants) and the values of the differential adsorption heat, which are close to those of the surface zero filling. These thermodynamic characteristics of adsorption have shown that the #alpha#-BN, line the graphitized thermal carbon black, is not a specific adsorbent.
In this study, thermoluminescence (TL) dating of archaeological artefacts from Geboltskirchen (Upper Austria) and Haselbach (Lower Austria) has been carried out. To receive a comparison with TL dating, all samples have been investigated additionally by means of infrared-stimulated luminescence (IRSL) analysis. The samples were prepared according to the common fine-grain technique. All important dating parameters such as potassium concentration, thorium/uranium ratio, moisture content, etc. were determined. A methodology for IRSL was developed, describing all steps of the procedure from samplepreparation to measurement for any kind of ceramic artefacts. Dating results from TL and IRSL investigations of ancient pottery from Geboltskirchen and Haselbach will be discussed.
LiFePO{sub 4} cathode materials with distinct particle sizes were prepared by a planetary ball-milling method. The effects of particle size on the morphology, thermal stability and electrochemical performance of LiFePO{sub 4} cathode materials were investigated. The ball-milling method decreased particle size, thereby reducing the length of diffusion and improving the reversibility of the lithium ion intercalation/deintercalation. It is worth noting that the small particle sampleprepared using malonic acid as a carbon source achieved a high capacity of 161 mAh g{sup -1} at a 0.1 C rate and had a very flat capacity curve during the early 50 cycles. However, the big particle samples ({proportional_to}400 nm) decayed more dramatically in capacity than the small particle size samples ({proportional_to}200 nm) at high current densities. The improvement in electrode performance was ...
Samplesprepared using the focused ion beam (FIB) inevitably contain the surface damage induced by energetic Ga"+ ions. An effective method of removing the surface damage is demonstrated using a plasma cleaner, a device which is widely used to minimize the surface contamination in scanning transmission electron microscopy (STEM). Surface bombardment with low-energy Ar"+ ions was induced by biasing the sample immersed in the plasma source, so as to etch off the surface materials. The etch rates of SiO_2, measured with a bias voltage of 100-300 V, were found to vary linearly with both the time and bias and were able to be controlled from 1.4 to 9 nm/min. The removal of the Ga residue was confirmed using energy dispersive spectroscopy (EDS) after the plasma processing of the FIB-preparedsample. When the FIB-preparedsample was processed via ...
Marketing-led enterprise change management initiated by a major UK contractor is explored in this paper as a contrast to procurement-led changes to projects driven by clients. Procurement-led initiatives try to induce changes to behaviour through market governance. Relationship marketing and management proactively change organizational behaviour, the enterprise taking responsibility for its own destiny. Investment and resource allocation, and organizational behaviour have posed constraints, particularly concerning service continuity in construction. Overcoming these constraints offers opportunities for delivering service improvements and adding value for clients and yielding further increases in repeat business and increasing profitability. Relationship marketing is the conceptual starting...
A novel single-step synthetic method for the preparation of anatase N-doped TiO"2 nanocrystalline at low temperature has been devoleped. The N-doped anatase TiO"2 nanoparticles were synthesized by sonication of the solution of tetraisopropyl titanium and urea in water and isopropyl alcohol at 80^oC for 150min. The as-preparedsample was characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy and UV-vis absorption spectrum. The product structure depends on the reaction temperature and reaction time. The photocatalytic activity of the as-prepared photocatalyst was evaluated via the photodegradation of an azo dye direct sky blue 5B. The results show that the N-doped TiO"2 nanocrystalline prepared via sonication exhibit an excellent photocatalytic...
Samples of air-dust-concentration- and air-dust-deposit measurements were digested by a standardized wet digestion procedure and the amounts of substances in the dust according to class I TA Luft by Atomic Emission Spectroscopy with Inductively Coupled Plasma (AES-ICP). The characteristic values for procedures according to VDI 2449, sheet 1, were determined for lead, vanadium, cadmium, chromium, copper, nickel and zinc. By partial automatic control of the digestion procedure the personel expenditure of work could be reduced by a factor 13. Dust filter samples were analysed without samplepreparation by evaporating the material with a solid state laser. The absolute detection limit was between 1 and 100 ng/cm"2 for the elements arsenic, cadmium, cobalt, chromium, mercury, antimony, selen and thallium. For sampling by means of the Beta-Staubmeter the relative detection limits for the ...
The aim of a joint effort by different research teams was to provide an improved procedure for enzyme activity profiling of field-sampled ectomycorrhizae, including recommendations on the best conditions and maximum duration for storage of ectomycorrhizal samples. A more simplified and efficient protocol compared to formerly published procedures was achieved by using manufactured 96-filter plates in combination with a vacuum manifold and by optimizing incubation times. Major improvements were achieved by performing the series of eight enzyme assays with a single series of root samples instead of two series, reducing the time needed for samplepreparation, minimizing error-prone steps such as pipetting and morphotyping, and facilitating subsequent DNA analyses due to the reduced sequencing ...
In this work, we report the preparation of lead titanate (PT) nanoceramics (with an average grain size of ~200nm in diameter) by using hydrothermal PT nanoparticles as start materials and characterized the dielectric and ferroelectric properties. The dielectric constant of the ceramic was found to be ~180 (at 1kHz) at room temperature and reached a maximum value of 8330 at ~490^oC, suggesting that the Curie temperature of the nanoceramics is consistent with the known value of PT crystals. Ferroelectric domains and hysteresis loops were obtained through piezoelectric force microscopy measurements, which provide direct and clear evidence for the ferroelectricity in the nanoceramic samples.
Mesporous anatase-phase TiO(2) hollow spheres with high photocatalytic activity were prepared by hydrothermal treatment and self-transformation of amorphous TiO(2) solid spheres in an NH(4)F aqueous solution. The preparedsamples were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, N(2) adsorption-desorption isotherms and UV-vis absorption spectroscopy. The photocatalytic activity was evaluated by photocatalytic oxidation decomposition of acetone in air under UV irradiation. It is found that F(-) plays an essential role in the formation of TiO(2) hollow spheres. F(-) not only induces the hollowing of TiO(2) solid spheres, but also promotes the crystallization of anatase TiO(2) nanocrystals. A possible formation mechanism for the TiO(2) hollow spheres by localized Ostwald ripening or chemically induced self-transformation is proposed based on the ...
Fe-doped TiO2 hollow spheres (Fe-THs) were synthesized by sol?gel process using carbon spheres as templates. The preparedsamples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV?vis diffuse reflectance spectrum (DRS), N2 adsorption?desorption isotherms, Electron paramagnetic resonance (EPR) spectroscopy and Photoluminescence emission spectroscopy (PL). UV?vis spectra showed that Fe3+ doping could extend the absorption edge to the visible region. EPR spectra showed that Fe3+ was incorporated into the crystal lattice of TiO2, which could inhibit the recombination of photo-induced electron?hole pairs and improve the photocatalytic activity. The photocatalytic activities of the preparedsamples were evaluated for the degradation of dye Reactive Brillia...
The growth of silver chloride nanoparticles on ancient textile was achieved by sequential dipping steps in alternating bath of potassium chloride and silver nitrate under ultrasound irradiation. The effect of ultrasound irradiation and sequential dipping steps in growth of the AgCl nanoparticles has been studied. These systems depicted a decrease in the particles size accompanying a decrease in the sequential dipping steps. The samples were characterized with powder X-ray diffraction (XRD) and scanning electron microscopy. XRD analyses indicated that the prepared AgCl nanoparticles on fiber were crystalline. The textile samples containing AgCl nanoparticles were tested for their antibacterial efficacy against Escherichia coli and were found to possess significant antibacterial activity.
Polyester WPC (wood-polymer composite) systems are one of the promising materials for multiple uses increasing the mechanical properties, provided that their dimensional stability can be improved. Possibility was pursued for the improvement in the dimensional stability of the polyester WPC systems prepared by electron beam irradiation. The impregnation of the mixture of polyester and monomer into both oven-dried beech veneers and preswollen wood was followed by mutual irradiation process. Polymerization was carried out at total dosage of 6 Mrad to the respective surfaces of samples by an electron beam accelerator, and the reaction was completed by heating at 80 deg C for 24 hr. The dimensions of the samples were measured primarily in the tangential direction, and their dynamic modulus and loss modulus were measured by a Rheovibron DDV-2 and the vibrating reed method. The results and the discussion are given for the reaction ...
Polyester WPC (wood-polymer composite) systems are one of the promising materials for multiple uses increasing the mechanical properties, provided that their dimensional stability can be improved. Possibility was pursued for the improvement in the dimensional stability of the polyester WPC systems prepared by electron beam irradiation. The impregnation of the mixture of polyester and monomer into both oven-dried beech veneers and preswollen wood was followed by mutual irradiation process. Polymerization was carried out at total dosage of 6 Mrad to the respective surfaces of samples by an electron beam accelerator, and the reaction was completed by heating at 80 deg C for 24 hr. The dimensions of the samples were measured primarily in the tangential direction, and their dynamic modulus and loss modulus were measured by a Rheovibron DDV-2 and the vibrating reed method. The results and the discussion are given for the reaction ...
A new series of anatase TiO2 hollow structures were prepared by a facile hydrothermal process. When the hydrothermal time was increased from 20min to 72h, the resulting TiO2 solid spheres gradually transformed into TiO2 hollow spheres with higher surface crystallinity and exposed {001} facets. The as-prepared TiO2-72h sample exhibited the highest activity comparing to other TiO2-based samples and commercial product Degussa P-25 towards the selective photocatalytic oxidation of toluene to benzaldehyde. Such great photocatalytic performance was mainly attributed to enhanced UV-adsorption and better charge separation efficiency due to higher surface crystallinity of TiO2-72h.
A programme has been initiated by the Coordinating Office for Monitoring of enhanced natural radioactivity of the Federal Office for Radiation Protection to investigate different kinds of sample materials with enhanced naturally occurring radioactivity (NORM) such as scales from oilfield and naturally gasfield pipes, blast furnace sludge and sinter dust from the production of pig iron, as well as bauxit and red mud from the production of aluminium oxide. The aim of these investigations is to find proper preparation and measuring methods which allow, in particular, a sample treatment with optimised effort combined with a reliable determination of the specific activities of the dominating radionuclides. Of particular interest is the method of gamma-ray spectrometry, since this method has been used for most of our studies of sample materials. Due to different compositions of calibration and ...
This report describes the cost, performance, and other key characteristics of an innovative technology for determining the presence or absence, and measuring the concentration, of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) in groundwater and soil, and in gaseous remediation process streams at hazardous waste sites. This new technology is Direct Sampling Ion Trap Mass Spectrometry (DSITMS). DSITMS introduces sample materials directly into an ion trap mass spectrometer by means of a very simple interface, such as a capillary restrictor or a polymer membrane. There is typically very little, if any, samplepreparation and no chromatographic separation of the sample constituents. This means that the response of the instrument to the analytes or contaminants in a sample is nearly instantaneous, and that analytical methods based on ...
The ElectroScan environmental scanning electron microscope (ESEM) is one of the most exciting new developments in the field of Electron Microscopy. The ESEM differs from conventional Scanning Electron Microscopes (SEM) by being able to examine materials including liquids and oils in their natural state with no prior samplepreparation. Accessory equipment, cooling, heating and manipulating devices allow the manipulation of samples thus making it possible for the first time to image dynamic processes such as wetting, drying, absorption, corrosion, melting, crystallisation, curing and fracturing at high magnification. Papers concerning the historical development of the ESEM are given in a bibliography at the end of this paper. 24 refs., 18 figs.
The adsorption properties of four samples of ..cap alpha..-BN were studied by means of gas chromatography. The particles of ..cap alpha..-BN particles, according to data obtained by electron microscopy, have the shape of thin platelets. A sample of ..cap alpha..-BN prepared from magnesium polyboride was found to be the most nearly homogeneous adsorbent. For a number of n-alkanes, benzene, and alkylbenzenes, data have been obtained on the retention volumes (Henry constants) and the differential heats of adsorption for surface coverages approaching zero. These thermodynamic data on the adsorption showed that ..cap alpha..-BN, like graphitized thermal carbon black, is a nonspecific adsorbent.
As part of the general QC/QA management of the k_0-standardization, three types of 'SMELS' (synthetic multi-element standards) are being developed to check the performance of k_0-NAA when implemented in a laboratory. Phenol-formaldehyde resin is proposed in this paper as the matrix of choice. Based on previous work, this material could be prepared with sufficient purity so as to make interferences with the spiking elements negligible. The matrix was found to be adequately resistant towards high neutron flux irradiation. A selection was made of compounds, soluble in ethyl alcohol, for spiking the prepolymer ethanolic solution with the elements of interest. Finally, some prototypes were prepared and a satisfactory homogeneity of the spiked elements was found for 50 mg sample intake.
The starting material for two certified and one candidate reference material was obtained from dried grass specially cultivated on a selected and well prepared soil. The Community Bureau of Reference (BCR) of the Commission of the European Communities produced two certified reference materials (CRM`s) from this dried grass: a rye grass material (CRM 281) certified in 1988 for the quality control of trace and toxic element analyses and a hay powder material (CRM 129) certified in 1989 for monitoring trace and minor elements. A fraction of the dried grass was used in 1993 for the preparation of a hay powder with a particle size of < 63 {mu}m using newly developed grinding techniques. This paper compares the production methods of these three materials and the obtained particle size distribution of the powders. The analytical evaluation of these production methods was carried out by solid sampling Zeeman atomic absorption ...
An on-going inter-comparison programme which is focused on assessing and establishing consensus protocols to be applied in the identification, selection and sub-sampling of materials for subsequent "1"4C analysis is described. The outcome of the programme will provide a detailed quantification of the uncertainties associated with "1"4C measurements including the issues of accuracy and precision. Such projects have become recognised as a fundamental aspect of continuing laboratory quality assurance schemes, providing a mechanism for the harmonisation of measurements and for demonstrating the traceability of results. The design of this study and its rationale are described. In summary, a suite of core samples has been defined which will be made available to both AMS and radiometric laboratories. These core materials are representative of routinely dated material and their ages span the full range of the applied "1"4C time-scale. Two of the ...
Principal Component Analysis (PCA) is an important tool of dimension reduction especially when the dimension (or the number of variables) is very high. Asymptotic studies where the sample size is fixed, and the dimension grows [i.e., High Dimension, Low Sample Size (HDLSS)] are becoming increasingly relevant. We investigate the asymptotic behavior of the Principal Component (PC) directions. HDLSS asymptotics are used to study consistency, strong inconsistency and subspace consistency. We show that if the first few eigenvalues of a population covariance matrix are large enough compared to the others, then the corresponding estimated PC directions are consistent or converge to the appropriate subspace (subspace consistency) and most other PC directions are strongly inconsistent. Broad sets of sufficient conditions for each of these cases are specified and the main theorem gives a catalogue of possible combinations. In ...
Ferrite of system, namely Ni_1_-_xZn_xFe_2O_4 with x = (0.0, 0.2, 0.4, 0.6, 0.8, 1.0), have been prepared by solid state reaction to investigate the effect of gamma rays irradiations using Co"6"0 source on the cation distribution, structural and magnetic properties. The unirradiated and irradiated samples were then subjected to characterization techniques such as X-ray diffraction, magnetization and AC susceptibility. The results of these characterizations are found to be different for irradiated from that of the pristine sample. The modifications in respect of irradiated samples are explained in terms of the ion-induced disorder. The important result of #gamma#-irradiation on the cation distribution, structural and magnetic properties is the change of ratio Fe"2"+/Fe"3"+. Possible reasons on the results are proposed.
In Tarapur Atomic Power Station unit-3 and 4, which is 540 MWe pressurized heavy water reactor, tritium is produced in primary heat transport system and moderator system. Tritium is a major contributor to the internal dose. Internal dose contributes about 30% of the collective dose. Internal dose monitoring and its control are important to control the collective dose. Estimation of internal dose is done by analysis of bioassay samples of radiation workers. In a month, about 7000 bioassay samples are analysed for the internal dose assessment during normal operation, and about 12000 during the biennial shut down of the reactor. To enhance the samplepreparation and counting performance, minimize the entry errors and reduce the processing time, barcode based label generation system was developed for the internal dose monitoring. This paper discusses about the use of barcode system in the internal dose ...
An allegation was made to the Office of Inspector General (OIG), and also reported in the press, regarding possible kickbacks in connection with a proposed Westinghouse Savannah River Company (WSRC) subcontract with the Computer Sciences Corporation (CSC) for outsourcing information technology (IT). OIG investigative activity did not substantiate this allegation. However, in the course of investigating the allegation it came to the OIG`s attention that WSRC`s selection of CSC for this proposed subcontract had possibly involved significant deviations from procurement rules and regulations. Accordingly, the specific objective of this review was to determine if the selection of CSC as a proposed subcontractor was made in accordance with appropriate procurement rules and regulations. In the course of our review, the Department of Energy`s (DOE) Savannah River Operations Office (SR) made the decision to disapprove WSRC`s proposed subcontract with ...
Cooperative procurement is a variation of public purchasing which may be used as an instrument to transform the market and stimulate innovation enhancing environmental performance. The core of the procedure is the following: Coordinated by a central agency a group of buyers - public administrations, but also private companies, associations, etc. - gets together and jointly formulates a catalogue of performance requirements for a specific product truly suiting their preferences. This catalogue may contain (combinations of) requirements not yet available on the market and includes energy efficiency and/or environmental performance among other preferences important to the users. On the basis of the product requirements the buyer group launches a call for tenders, evaluates the bids received from the manufacturers and commits to buying the winning product. Thus, a market is provided for the most successful innovators in a given area of technology. The paper discusses ...
Data of thermally stimulated luminescence (TSL) of single (Cu), double (Cu, Mn) and triple (Cu, Mn, Gd) activated SrS phosphors, which throws light on the nature and distribution of deeper traps have been presented. The samples are prepared by Bhawalkar's method and excited by UV 365 nm and #gamma#-rays to study the phenomenon. (author). 8 refs., 2 figs., 1 tab.
The physical foundations and methodology are described of radionuclide X-ray fluorescence analysis. The sources are listed of air, water and soil pollution, and the transfer of impurities into biological materials is described. A detailed description is presented of the sampling of air, soil and biological materials and their preparation for analysis. Greatest attention is devoted to radionuclide X-ray fluorescence analysis of the components of the environment. (ES).
The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with samplepreparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average "2"4"2Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average "2"4"2Am tracer yield is 85 +- 7% for 40 determinations.
The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with samplepreparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average /sup 242/Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average /sup 242/Am tracer yield is 85 +- 7% for 40 determinations.
This paper reports the results of a fine-probe EDS microanalytical study of cellular precipitation in a Cu-Ti binary alloy. Compositional profiles across the solute depleted Cu-rich FCC lamellae and the Cu_4Ti lamellae within isothermally formed cellular colonies were measured in a FEG-TEM from thin-foil specimens prepared by conventional electropolishing and by a technique using a Ga"+ focused ion-beam (FIB). The Cliff-Lorimer ratio method, with an absorption correction, was employed to quantify the compositions. Two FIB samples were prepared with different orientations of the lamellae with respect to the ion-milling direction. The compositional profiles across the Cu-rich FCC lamellae and the Cu_4Ti compound lamellae in both the FIB-preparedsamples and the electropolished sample were, within experimental error, numerically equivalent. The composition of the ...
The present work focuses on the transformation of high-purity Ni powder blends of controlled volume fractions (40 and 60 %) of nanometre-sized (100 nm) and micrometre-sized (544 nm) particles into bulk samples as part of a strategy for producing ultrafine-grained materials usefully exhibiting both strength and ductility. The process involved cold isostatic pressing at 1.5 GPa and sintering. The resulting bulk samples had relative densities near 95 %, were texture-free, and exhibited two different grain size distributions with an average value of 600 #+-# 30 nm. The mechanical properties were investigated by compression and microhardness tests, both at room temperature, and compared to the behaviour of a sample processed from micrometre-sized powder only. Samplesprepared from the blends exhibited high yield stresses of 440 and 550 MPa after compression, and they did sustain work ...
During the present study concentration of nine elements (K, Ca, Mn, Fe, Cu, Zn, Se, Br and Pb) in different tissues of mud crab Scylla serrata from Mahanadi estuary, India were determined by the external PIXE set up at Institute of Physics, Bhubaneswar, India. The study demonstrates the effectiveness of the technique in analyzing both soft and hard tissue samples from marine organisms and opens the door for non-destructive, multi-elemental analysis of tissue samples with a very little samplepreparation by direct irradiation. This technique can be well utilized for analyzing the tissue samples for environmental, toxicological and nutritional purposes. The study also demonstrates the elemental concentrations from tissue samples of any crustaceans from Mahanadi estuary for the first time. Sex based difference in the elemental concentration of the mud crabs were ...
As part of efforts to develop improved methods for NMR protein samplepreparation and structure determination, the Northeast Structural Genomics Consortium (NESG) has implemented an NMR screening pipeline for protein target selection, construct optimization, and buffer optimization, incorporating efficient microscale NMR screening of proteins using a micro-cryoprobe. The process is feasible because the newest generation probe requires only small amounts of protein, typically 30-200 ?g in 8-35 ?l volume. Extensive automation has been made possible by the combination of database tools, mechanization of key process steps, and the use of a micro-cryoprobe that gives excellent data while requiring little optimization and manual setup. In this perspective, we describe the overall process used by the NESG for screening NMR samples as part of a sample optimization process, assessing optimal construct design and ...
The MonoPrep Pap Test (MPPT; MonoGen, Lincolnshire, IL) is a novel, liquid-based specimen collection and processing technology for cytologic and molecular testing. Its usefulness in the detection of cervical cancer and its precursors was evaluated in a multicenter, masked, adjudicated, split-sample study of 10,739 samples. After preparation of a conventional smear, the residuum on the collection device was rinsed into a collection vial from which an MPPT slide was prepared. Accuracy was assessed by masked reference interpretation by an independent pathologist. Slides prepared by MPPT, compared with smears, yielded statistically significant increases in relative sensitivity for atypical squamous cells of undetermined significance and worse, atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesion/atypical glandular cells and worse, and low-grade squamous ...
Thinning specimens to electron transparency for electron microscopy analysis can be done by conventional (2-4 kV) argon ion milling or focused ion beam (FIB) lift-out techniques. Both these methods tend to leave 'mottling' visible on thin specimen areas, and this is believed to be surface damage caused by ion implantation and amorphisation. A low energy (250-500 V) Argon ion polish has been shown to greatly improve specimen quality for crystalline silicon samples. Here we investigate the preparation of technologically important materials for nanoanalysis using conventional and lift-out methods followed by a low energy polish in a GentleMill"T"M low energy ion mill. We use a low energy, low angle (6-8 deg.) ion beam to remove the surface damage from previous processing steps. We assess this method for the preparation of technologically important materials, such as steel, silicon and GaAs. For these materials the ability to ...
The establishment of the domestic market in Europe requires rules for the assignment of orders, with which a standardization of the rules of competition can be achieved and with which a discrimination of individual bidders can be prevented. Clients and contractors of power station equipments equally are affected by the definitions for the assignment of orders. The contribution under consideration is a regulation for the procurement of steam turbine systems. It is a supplement of the European standard DIN EN 45510:1998. The regulation integrates the former terms of delivery of association of the electricity industry (VDEW) for steam turbines as well as the collection and evaluation of a multiplicity of experiences of the VGB regulations.
The long-term support required from Canada in the operation and maintenance of overseas CANDU nuclear generating stations after commercial operation has commenced is described, with reference entirely to the KANUPP reactor. This includes: technical support to station staff to increase plant reliability and maintainability; assistance with plant improvements; procurement of spares and consumables; and assistance with training programmes. This technical support may be provided by a small number of Canadian staff actually resident at the power station; by short-term visits of Canadian specialists to site and by technical and procurement services provided from Canada. Examples of technical problems experienced are given, showing typical services required from Canada.
This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The main objective of this project was to engineer and procure an electron beamline compatible with the operation of a 1-kW free-electron laser (FEL). Another major task is the physics design of the electron beam line from the end of the wiggler to the electron beam dump. This task is especially difficult because electron beam is expected to have 20 kW of average power and to simultaneously have a 25% energy spread. The project goals were accomplished. The high-power electron design was completed. All of the hardware necessary for high-power operation was designed and procured.
The goal of this project was to develop a new technology for preparingsamples for transmission electron microscopy (TEM) on the basis of ion fine beam processing. For this purpose processes of ion-beam-assisted removal (sputtering), separation, sample handling and ion-beam-assisted chemical etching as well of system-inherent components were examined. As an alternative to a Ga-source a liquid-metal ion source based on a AuGeSi alloy was developed, characterised and used in the FIB 4400. [German] Aufgabe des Projektes war die Entwicklung einer neuen Technologie zur Probenpraeparation fuer die Transmissions-Elektronenmikroskopie (TEM) auf der Basis der Ionenfeinstrahlbearbeitung. Dazu wurden Prozesse der ionenstrahlgestuetzten Abtragung (Sputtern), der Abscheidung, des Probenhandling, des ionenstrahlgestuetzten chemischen Aetzens sowie systemeigener Komponenten untersucht. Als Alternative zur Ga-Quelle wurde eine ...
Bremstrahlung Isochromat Spectroscopy (BIS). The XES spectra were collected using a Specs electron gun for the excitation and the XES 350 grating monochromator and channel plate system from Scienta as the photon detection. Spectra were collected in 'normal mode,' where the electron gun kinetic energy (KE) and the energy position of the center of the channel plate were both fixed and the energy distribution in the photon (hv) spectrum was derived from the intensities distributed across the channel plate detector in the energy dispersal direction. The polycrystalline Ce sample was oxidized by exposure to air at ambient pressures. After introduction to the ultra-high vacuum system, the oxidized sample was bombarded with Ar, to clean the topmost surface region and stabilize the surface and near surface regions. Although CeO{sub 2} would be the thermodynamically preferred composition in an oxygen rich environment, the combination ...
The requirements are given as placed on the development, procurement, maintenance, and application of software for the creation or processing of data during the design, construction, operation, repair, maintenance and safety-related upgrading of nuclear power plants. The verification and validation processes are highlighted, and the requirements put on the software documentation are outlined. The general quality assurance principles applied to safety analyses are characterized. (J.B.). 1 ref.
To meet growth in the fast developing Pearl River Delta economic zone in China`s Guangdong province, a 270 MW oil-fired combined cycle at Foshan was built and commissioned in only 22 months from financial closure. This article describes the Foshan power station, specifications, design, procurement, construction and operating concerns. 5 figs.
... Most of the received offers were ecolabelled cleaning products and were not more expensive than conventional products. Case 3: The procurement of sustainable cleaning services 104kB Eight cooperating municipalities in the Netherlands needed a new contractor for cleaning services. They wanted to use SPP criteria as well as finding a social employment organisation. SPP criteria for cleaning services were used to set minimum requirements in ...
(1) Most ancillary services needed for real-time control of the transmission grid and to meet operating criteria can be competitively supplied and competitively procured. (2) The independent service operator (ISO) must directly control the generators and loads, which supply ancillary services. (3) Comparability of access to ancillary services is achievable through the ISO-based competitive market structure.
The purpose is to provide a source of information that can be used to assist personnel in the planning, training, and execution of radiological work using the principles of ALARA. This document is not intended to replace HNF or WHC Control Manual requirements. The ALARA Tools-List provides detailed information on the use and procurement of engineered controls, mockup training guidelines, and good radiological work practices that have been proven to be ALARA.
This paper deals with preparation of PE clay nano composite specimen for transmission electron microscopy (TEM) and studying the difference between dispersion of clay in low density polyethylene using poly(hydrogen methyl siloxane) (PHMS) as coupling agent and untreated one. Argon ion milling is the conventional means by which film sections are thinned to electron transparency for TEM analysis, but this technique exhibits significant problems. In particular, selective thinning and imaging of sub-micrometer inclusions during sample milling are highly problematic. We have achieved successful results using the focused ion beam (FIB) lift-out technique, which utilizes a 30 kV Ga"+ ion beam to extract electron transparent specimens with nanometer scale precision. Using this procedure, we have prepared a number of thin film materials representing a range of structures and compositions for TEM analysis. We believe that FIB milling ...
A series of Gd-substituted M-type barium hexaferrites has been prepared by the ceramic route, according to the formula (Ba{sub 1-x}Gd{sub x})O.5.25Fe{sub 2}O{sub 3} (x=0-0.30). XRD analysis revealed that all the samples present primarily an M-type structure. Samples x=0 and x=0.05 are single-phase. Hematite (Fe{sub 2}O{sub 3}) and GdFeO{sub 3} were detected in the remaining samples. Coercivity (H{sub c}) shows remarkably high values, {approx}293kA/m for x=0.20 and 0.30 with a maximum of 322kA/m for x=0.25. Specific saturation magnetization ({sigma}{sub sat}) of the samples presents a small increase up to x=0.10. The microstructure examination indicates that Gd may act as a grain growth inhibitor.
A series of Gd-substituted M-type barium hexaferrites has been prepared by the ceramic route, according to the formula (Ba_1_-_xGd_x)O.5.25Fe_2O_3 (x=0-0.30). XRD analysis revealed that all the samples present primarily an M-type structure. Samples x=0 and x=0.05 are single-phase. Hematite (Fe_2O_3) and GdFeO_3 were detected in the remaining samples. Coercivity (H_c) shows remarkably high values, #approx#293kA/m for x=0.20 and 0.30 with a maximum of 322kA/m for x=0.25. Specific saturation magnetization (#sigma#_s_a_t) of the samples presents a small increase up to x=0.10. The microstructure examination indicates that Gd may act as a grain growth inhibitor.
Bethlehem Steel Corporation (BSC), in conjunction with the Department of Energy (DOE) is conducting a Clean Coal Technology (CCT) project at its Sparrows Point, Maryland Coke Oven Plant. This innovative coke oven gas cleaning system combines several existing technologies into an integrated system for removing impurities from Coke Oven Gas (COG) to make it an acceptable fuel. DOE provided cost-sharing under a Cooperative Agreement with BSC. This Cooperative Agreement requires BSC to develop and conduct and Environmental Monitoring Plan for the Clean Coal Technology project and to report the status of the EMP on a quarterly basis. It also requires the preparation of a final report on the results of the Baseline Compliance and Supplemental Sampling Programs that are part of the EMP and which were conducted prior to the startup of the innovative coke oven gas cleaning system. This report is the Baseline Sampling Program report.
Research was conducted to determine the effect of electrochemical aging on large area arc-sprayed zinc anodes for cathodic protection of bridges and other reinforced concrete structures. The study focused on the influence of total charge passed and concrete surface preparation on the bonding of the zinc to the concrete. Half of the samples were preheated prior to being arc-sprayed with zinc. The preheated samples had initial bond strengths that were 80% higher than the unheated samples. This difference in bond strength became insignificant after the passage of approximately 200 kC/m{sup 2} (5.2 A-h/ft{sup 2}) and bond strengths for all samples started to decrease after approximately 600 kC/m{sup 2} (15.5 A-h/ft{sup 2}). These changes in bond strength were correlated with observed changes in the permeability of the zinc coating to water, the electrical behavior of the zinc-concrete ...
We reported the radio-protective effect of DTT. The treatment of DTT increased cell survival after gamma-irradiation, decreased in the frequencies of micronucleus, and reduction in DNA fragmentation and apoptotic cells. Induction of apoptosis after UV-C irradiation was revealed by the changes in the relative cell death, increase in the relative amount of apoptotic cells, and the induction of DNA fragmentation. About 100 medicinal plants were purchased and methanol extract samples were prepared. Radio-protective and radio-sensitizing activities of these samples were screened. Seven samples showed above 20% radio-protective activities: Salvia miltiorrhiza, Areca catechu, Cornus officinalis, Alpiniae officinari rhizoma, Meliae fructus, Alpiniae katsumadaii semen, Betulae cortex. Acanthopanax sessiliflous showed the highest radio-sensitizing effect and 10 other samples revealed moderate ...
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 samplepreparation. The Pyrolysis-Gas Chromatography(PGC) is a precise and reliable method for performing both quantitative and qualitative analysis 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 ...
In this paper, we prepared by the sol-gel method alkaline titania catalysts, doped by gelling titanium alkoxide with aqueous solutions containing potassium, rubidium or cesium chlorides. XRD patterns showed that samples annealed at 400 and 600degreeC contained a single crystalline phase, anastase. Specific surface areas were higher in samples annealed at 400degreeC (>100m2/g) than in those annealed at 600degreeC (25m2/g). The weight density of basic sites determined by CO2-TPD drastically diminished in samples treated at 600degreeC. Catalysts were tested for the self-condensation of acetone at 300degreeC; main reaction products were isomesityl oxide, mesityl oxide and mesitylene. Samples annealed at 600degreeC showed lower acetone conversion rate and low formation of mesitylene than that o...
Abstract Preparation of antibacterial alginate films incorporating extruded white ginseng (EWG) extracts was attempted. The antibacterial effect of EWG extract on six selected food pathogenic bacteria was compared with the effect of red ginseng (RG) and white ginseng (WG) extracts. The EWG was processed in a twin-screw extruder with feed moisture of 20% and barrel temperature of 115 and 130C. The data obtained by agar diffusion assay demonstrated that the film containing 1-g/mL of EWG at barrel temperatures of 115 (EWG-115) and 130C (EWG-130) exhibited stronger antibacterial activity against the four strains of bacteria than the other extracts RG and WG. All films sampled showed reduction in bacteria cell counts (log cycle) compared with the control. After 24-h of incubation, Pseudomonas a...
Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.
Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density magnetic storage systems.
The aim of this study was to develop a nanostructured Nb2O5-natural hydroxyapatite bulk composite to serve as an alternative biocompatible bulk material for implants. A set of samples of hydroxyapatite from fish bones with different concentrations of Nb2O5 were designed. They were prepared through a milling process, compacted under different pressures (350, 450, 550 and 650MPa) and sintered in air atmosphere at 1000^oC for 1h. The results revealed that the prepared composites presented strong interactions between the two elements and showed improvement in the sinterability with significant densification and microstructure changes, suggesting that they are promising for implants meant to replace bone tissues.
Ferroelectric [Pb_0_._9_2(La_1_-_zSb _z)_0_._0_8][Zr_0_._6_0Ti_0_._4_0]O_3 for z = 0.0, 0.3, 0.6, 0.9 and 1 were prepared from their constituent oxides by a solid state reaction technique. The powders were calcined in the temperature range of 1000 deg. C for 6 h. Phase formation, crystal structure and lattice parameter were investigated by X-ray diffraction (XRD) technique. The compacts were sintered at 1250 deg. C for 2 h and their dielectric, ferroelectric and conductive properties were measured. The ferroelectric behavior of the doped samples was studied from their hysteresis loop.
Abstract Nanocomposites based on SnO2 with carbon scaffold were used as highly porous anode films on Ni substrates. The films were obtained by in situ deposition of the particles without any binder or excess carbon black avoiding any secondary treatment. Compared to similarly prepared uncoated SnO2 nanoparticles as well as conventionally prepared powder samples the capacity loss of the in situ deposited nanocomposite films is significantly reduced. Thus, this newly developed anode material combined with in situ film formation is a promising approach for high capacity anodes in Li-ion batteries. SEM-micrograph of a SnO2/C nanoparticle film.
The aims of the present work were to investigate possible compatibility between sodium zirconium phosphate (NZP) and Synroc titanate phases, to prepare NZP-based waste forms by hot-pressing rather than sintering, and to investigate the incorporation in NZP of (a) Cs/Sr as simulated heat-generating nuclides; (b) simulated actinides; and (c) simulated Purex waste. The NZP samples were prepared by methods similar to those used for Synroc. The precursor NZP phase was formed from tetrabutyl zirconate Zr(OC{sub 4}H{sub 9}){sub 4}, sodium nitrate, and 85% orthophosphoric acid. Simulated waste nitrate solutions were then mixed with the liquid precursor. After stir drying of the precursor, calcination was carried out at 700{degree}C to remove nitrates and organics.
Under different sintering temperatures(340 degrees C, 440 degrees C, 540 degrees C, 640 degrees C), four TiO2 particles were prepared. The crystal types of all four samples were found to possess anatase structures by XRD. It was obtained by N2 experimental adsorption at low temperature (77K) that their surface areas and average pore size were between 79 and 124 m2/g, 56.8 and 254.8 A respectively. The pore structure of TiO2 particles was characterized by scanning electron microscope (SEM). The tests of adsorption dynamics for FGD and the performance of SO2 removal were investigated in a fixed-bed system for different samples. The results show that SG540 sample which made at 540 degrees C sintering temperature had the most quality among the four samples. It can adsorb SO2 of 38.9 mg for one gram SG540 sample. Different operating conditions for SG540 such as ...
Methods currently being used or developed for the elemental analysis of materials are chemical analysis, non-destructive inspection and calorimetry. The chemical analysis, 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 chemical analysis, with a less possibility for instruments to be contaminated. In addition, as interests in the environment and the life quality are increased, a detailed analysis on the environmental impacts is also required. Satisfying all of the above-mentioned, ...
The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 deg. C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in ...
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 design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal cond...
We investigated phase transition of ilmenite-type AgSbO3 to pyrochlore by post-heat treatment and the synergy effect of the mixed phases of AgSbO3 on the photocatalytic activities to enhance the activities. The AgSbO3 with an ilmenite structure was prepared by a cation-exchange method. Phase transition from the ilmenite to pyrochlore occurred by proper control of post-heat treatment. The sample that was obtained by post-heat treatment of ilmenite-type AgSbO3 at 660^oC for 3h consisted of both of the ilmenite and pyrochlore phases, and the sample at 685^oC for 4h mainly consisted of the pyrochlore phase. Together with an increase in the ratio of the pyrochlore phase, the optical absorption spectra blue-shifted. The band gaps of single phases of the ilmenite and the pyrochlore were 2.4 and 2...
Two of eight differently prepared copper stabilizer samples, previously irradiated in the RTNS-II at LLNL, the IPNS-1 and the BSR at ORNL, have been irradiated to a fluence of 1.33 /times/ 10/sup 22/ n/m/sup 2/ at RTNS-II. During the course of the irradiation the samples were periodically removed (without warming) for measurements of the transverse magnetoresistance and returned for continued irradiation. This experiment extends the range of neutron-irradiation-induced resistivity by a factor of five over the previous experiments. A simple model is developed which reproduces the magnetoresistance results of all the experiments to an accuracy of 2.5%. 13 refs., 6 figs.
A high-precision Li isotope analysis was developed for determining the Li"+ ion emitted from lithium phosphate as an ion source material by a Re double-filament ionization method in the thermal ionization mass spectrometry. In this method, Li isotopic fractionation is distinctly less sensitive to the filament temperature than those in the previous methods, and stable and high ion beam intensity of more than 8 x 10"-"1"1 A for "7Li is obtained. These advantages in determining the "7Li/"6Li ratio result in the analytical reproducibility of 0.26 per mille (1#sigma#). Furthermore, the samplepreparation is simple and the low temperature (850degC) required by this method ensures the analysis of the isotopic composition of small amounts of Li with less influence of Li contamination to the sample, compared with the previous methods. (author).
High molecular weight samples of the novel biodegradable polyester poly(ethylene sebacate) (PESeb) were synthesized. Miscible poly(ethylene sebacate)/poly(4-vinyl phenol) semicrystalline/amorphous blends were prepared by applying the solvent casting method. Miscibility was proved by the single composition dependent glass transition temperature over the entire composition range observed in DSC traces of the quenched blend samples and also by the melting point depression. The Flory-Huggins interaction parameter was found to be x12 = -1.3. Also, FTIR spectra supported the hypothesis of intermolecular interactions due to hydrogen bonding. The crystallization of PESeb in blends was studied. As expected, isothermal crystallization rates decreased in the blends with increasing the PVPh content. T...
N-doped TiO2 has been prepared by use of sol?gel systems containing titanium alkoxide, with nitric acid as the nitrogen source. The time needed for gelation of the systems was drastically reduced by ultrasonic irradiation. The peaks assigned to the nitrate and nitrous ions were observed by FT-IR measurement during the sol?gel reaction. The N-doping was confirmed by the observation of N?O peaks in the XPS spectrum of the sample heated at 400??C. The nitrate ion acted as an oxidizer of the ethanol solvent and titanium species. The TiO2 became doped with nitrogen oxide species as a result of reduction of nitrate ion incorporated into the dried gel samples. These results indicated that the added nitric acid was reduced during the sol?gel transition and heating process, and the resulting NO spe...
The following is the optimized pulsed laser deposition (PLD) procedure by which we prepared the final samples that were sent to LLNL. These samples are epitaxial multilayer structures of Si/YSZ/CeO/NSMO, where the abbreviations are explained in the following table. In this heterostructure, YSZ serves as a buffer layer to prevent deleterious chemical reactions, and also serves to de-oxygenate the amorphous SiO{sub 2} layer to generate a crystalline template for epitaxy. CeO and BTO serve as template layers to minimize the effects of thermal and lattice mismatch strains, respectively. More details on the buffer and template layer scheme are included in the manuscript [Yong et al., 2008] attached to this report.
This paper aimed to the evaluation of different kinds of sorbent material preparation and to the evaluation of their characteristics at different pH conditions by X-ray fluorescence analysis. This method is suitable for identification and determination of elements in samples of different character, state and origin because it is a polycomponent, non-destructive, fast and simple analytical method. Moreover, it allows timeadvantageous and reliable measurements. This paper studies problems concerning the determination of some selected elements (Mn, Fe, Ni, Cu, Zn, Pb) in pharmaceutical samples of sodium chloride in the solid state as well as in its solution by sorption on chelating extraction membrane 3M Empore"T"M and on the strongly acidic ion-exchanger Dowex 50Wx8. Conditions for the most effective sorption of determined elements are also interpreted. (author)
This paper aimed to the evaluation of different kinds of sorbent material preparation and to the evaluation of their characteristics at different pH conditions by X-ray fluorescence analysis. This method is suitable for identification and determination of elements in samples of different character, state and origin because it is a polycomponent, non-destructive, fast and simple analytical method. Moreover, it allows time-advantageous and reliable measurements. This paper studies problems concerning the determination of some selected elements (Mn, Fe, Ni, Cu, Zn, Pb) in pharmaceutical samples of sodium chloride in the solid state as well as in its solution by sorption on chelating extraction membrane 3M Empore? and on the strongly acidic ion-exchanger Dowex 50Wx8. Conditions for the most ef...
In preparation for studying the hydrolytic degradation of Estane 5703 in the plastic-bonded explosive PBX 9501, the sorption (solubility) and diffusion of water in PBX 9501 and each of its components are studied experimentally and modeled theoretically. Experiments are reported that measure the weight gain or loss due to a change in the relative humidity (RH). For all of the components, the equilibrium amount of water sorbed per gram of sample is linear in the RH at low relative humidities but curves upwards at higher relative humidities. This behavior is modeled with a water cluster model. Diffusion coefficients are determined by modeling the time dependence of the water concentrations assuming Fickian diffusion, and that fits the data for some of the materials. However, all the samples t...
Sales of iodized table salt (household use, bulk containers) have been flat in Germany since 1996/1997. Nevertheless, the amount of iodide excreted with the urine has been steadily increasing in the German population since 1993. We investigated the beverage iodine levels as possible source of the increased input of iodine into the food chain. No systematic studies on this topic have yet been carried out in Germany. A total of 510 samples were drawn from large grocery discounters who supply all German states with their products (35% fruit and vegetable juices, 35% beers, 10% pooled milk and yoghurt drinks, 10% mineral water, 10% soda). (1) Water-based beverage samples are prepared by solid-phase extraction and iodine concentration is determined by HPLC and electrochemical detection, (2) the...
Here we demonstrate that the as-prepared MCM-41 mesoporous silica material, which is synthesized using cetyltrimethylammonium bromide as a cationic surfactant exhibits very high capacity for perchlorate uptake from solutions. Thus we discover a new function for the as-synthesized mesoporous materials containing cationic surfactants. These materials are shown to have better capacity than the currently used activated carbon, which is preloaded with cationic surfactant. As-synthesized MCM-41 has a higher removal of perchlorate with 0.378???0.038?meq/g than the surfactant modified activated carbon sample, which removed 0.304???0.005?meq/g i.e., MCM-41 has a 24 % higher capacity than the surfactant modified activated carbon sample for perchlorate uptake because of higher surfactant content and ...
In this study, a novel graphene nanosheets (GNSs) coated solid phase microextraction (SPME) fiber was prepared by immobilizing microwave synthesized GNSs on a stainless steel wire. Microwave synthesized GNSs were verified by X-ray diffraction, field emission-scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM). GNS-SPME fiber was characterized using FE-SEM and the results showed the GNS coating was homogeneous, porous, and highly adherent to the surface of the stainless steel fiber. The performance and feasibility of the GNS-SPME fiber was evaluated under one-step microwave assisted (MA) headspace (HS) SPME followed by gas chromatography with electron capture detection for five organochlorine pesticides (OCPs) in aqueous samples. Parameters influencing the extra...
Purpose: To evaluate micro computed tomography (micro-CT) for the assessment of osteochondritis dissecans in comparison with histology. Material and Methods: Osteochondritis dissecans lesions of 3 patients were evaluated using micro-CT (0.125 mA, 40 keV, 60 m slice thickness, 60 m isotropic resolution, entire sample) and light microscopy (toluidine blue, 3-5 m slice thickness). The methods were compared regarding preparation time, detectability of tissue types and morphologic features of bone and cartilage. Results: Non-destructive micro-CT imaging of the entire sample was faster than histologic preparation of a single slice for light microscopy. Morphologic features of bone and cartilage could be imaged in a comparable way to histology. It was not possible to image cells or different tissue types of bone and cartilage with micro-CT. Conclusion: Micro-CT is a fast, non-destructive tool that may be a ...
Purpose: To evaluate micro computed tomography (micro-CT) for the assessment of osteochondritis dissecans in comparison with histology. Material and Methods: Osteochondritis dissecans lesions of 3 patients were evaluated using micro-CT (0.125 mA, 40 keV, 60 m slice thickness, 60 m isotropic resolution, entire sample) and light microscopy (toluidine blue, 3-5 m slice thickness). The methods were compared regarding preparation time, detectability of tissue types and morphologic features of bone and cartilage. Results: Non-destructive micro-CT imaging of the entire sample was faster than histologic preparation of a single slice for light microscopy. Morphologic features of bone and cartilage could be imaged in a comparable way to histology. It was not possible to image cells or different tissue types of bone and cartilage with micro-CT. Conclusion: Micro-CT is a fast, non-destructive tool that may be a ...
Nanocrystalline samples of Fe_8_0Mo_2_0 and Fe_5_0Mo_5_0 alloys were prepared by the mechanical milling method. The structure, lattice parameters, and crystallite size were determined by the X-ray diffraction. The magnetic properties of the milled products were determined by the Moessbauer spectroscopy. It was observed that in the case of the Fe_8_0Mo_2_0 alloy a solid solution of Mo in Fe was formed with the lattice parameters of the Fe increasing from 0.28659 nm to 0.29240 nm and the crystallite size decreasing from 250 nm to 20 nm. In the case of the Fe_5_0Mo_5_0 alloy there were no clear changes in values of the lattice parameters of Fe and Mo during the milling process, but the crystallite size decreased from 200 to 15 nm. Moessbauer spectra revealed different magnetic phases in the machanosynthesized Fe_Mo samples. In the case of the Fe_8_0Mo_2_0 alloy, the spectrum for the milled mixture indicated the formation of ...
Lyophilized human whole blood control material containing lead was prepared for internal and external quality assurance to evaluate and improve the analytical performance of lead. The samples were prepared in four different concentrations from outdated human whole blood stabilized with glucose and a citrate/phosphate buffer and provided under clean room conditions to avoid contamination. The lyophilized samples are easy to reconstitute with water. The materials were evaluated according to a statistical model. The lead concentrations in the specimens are close to blood lead levels usually following environmental and industrial exposure, particular in occupational health to the control of lead exposure at work regulations. The materials are available to the commercial as well as the scientific community. The Danish External Quality Assessment Scheme (DEQAS) for lead in blood is intended to complement the ...
It has been prepared composites materials by means of monomer penetration in pores of wood samples and later curing by means of gamma irradiation. The studied species were Hura crepitans L. (catahua), Aniba puchury-minor (C. Martinez) (mohena amarilla), and Calycophyllum spruceanum (Benth.) (capirona). These new materials exhibit smaller water absorption and better mechanical properties in comparison with native wood. The test tubes of catahua treated with the styrene-polyester mixture absorb only up to 10% humidity compared to the native species whereas its hardness is increased in a 100%. (author).
Using standards on phenol-formaldehyde resin base for assaying-activation analysis of geological specimens for gold and silver has bee the advantage of uniformly distributing Au and Ag in spesimens and possible preparing tablets of practically any form or size. The validity and accuracy of these standards have been studied for the cases of short irradiation. Conventional point standards were used as reference standards. The experiments carried out have shown that tablet resol standards are suitable for a mass assaying-activation analysis for gold and silver at practically any concentrations.
Spectroscopy of antihydrogen has the potential to yield high-precision tests of the CPT theorem and shed light on the matter-antimatter imbalance in the Universe. The ALPHA antihydrogen trap at CERN's Antiproton Decelerator aims to prepare a sample of antihydrogen atoms confined in an octupole-based Ioffe trap and to measure the frequency of several atomic transitions. We describe our techniques to directly measure the antiproton temperature and a new technique to cool them to below 10 K. We also show how our unique position-sensitive annihilation detector provides us with a highly sensitive method of identifying antiproton annihilations and effectively rejecting the cosmic-ray background.
Multi-cation #alpha#-Sialon ceramics were prepared using mixtures of samarium with calcium, magnesium, yttrium and ytterbium, and compared with a pure Sm-Sialon of equivalent total stabilising cation composition. A ratio of 80eq% samarium to 20eq% of the second stabilising additive was used. Samples were fired at 1820 deg C and subsequently heat treated at 1450 deg C. XRD phase analysis showed that all additives resulted in greater #alpha#-Sialon stability, and that calcium was the most effective additive for the stabilisation of the #alpha#-Sialon phase. Copyright (1998) Australasian Ceramic Society
The CeO{sub 2}-ZrO{sub 2}-Bi{sub 2}O{sub 3} samples with different bismuth content were prepared in this study. By the doping of Bi{sub 2}O{sub 3} into the lattice, TPR profiles of the CeO{sub 2}-ZrO{sub 2} shifted to lower temperatures and oxygen storage capacity increased remarkably. It is concluded that the reason for such a behavior is probably due to both the formation of oxygen vacancies which enhance the oxygen mobility and the simultaneous reduction of Ce{sup 4+} and Bi{sup 3+} in the mixed oxides. (authors)
The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.
The purpose of this work is to present a comprehensive, instructive analysis of the basis of radionuclide XRFA, to describe methods of samplepreparation for environmental analysis and to make the reader more familiar with the procedures, methods and instrumentation of radionuclide XRFA used in this field. This book discusses the use of radionuclide XRFA for solving analytical problems of the environment and information is presented concerning the current state of research and use of radionuclide XRFA in this significant area. The present volume will serve as a basic source of data and also as a laboratory handbook. refs.; figs.; tabs.
Progress is reported in several areas of research. The following cellulosic raw materials were selected for study: wheat, barley, and rice straws, rice hulls, sorghum, corn stover, cotton gin trash, newsprint, ground wood, and masonite steam-treated Douglas fir and redwood. Samples were collected, prepared, and analyzed for hexosans, pentosans, lignin, ash, and protein. Results of acid extraction and enzymatic hydrolysis are discussed. Yields of glucose, polyglucose, xylose, and arabinose are reported. Progress in process design and economic studies, as well as pilot plant process development and design studies, is summarized. (JGB)
X-ray photoemission spectroscopy has been used to measure the valence band offset {Delta}E{sub v} for the AlP/GaP (001) heterojunction interface. The heterojunction samples were prepared by molecular-beam epitaxy. A value of {triangle}E{sub v}=0.43 eV is obtained (staggered band alignment, with AlP valence band below that of GaP). 24 refs., 8 figs., 1 tab.
Many analytical chemistry methods normally used at the Savannah River site require repetitive procedures and handling of radioactive and other hazardous solutions. Robotics is being investigated as a method of reducing personnel fatigue and radiation exposure and also increasing product quality. Several applications of various commercially available robot systems are discussed involving cold (nonradioactive) and hot (radioactive) samplepreparations and glovebox waste removal. Problems encountered in robot programming, parts fixturing, design of special robot hands and other support equipment, glovebox operation, and operator-system interaction are discussed. A typical robot system cost analysis for one application is given.
This report is a summary of the progress and research produced for the Idaho National Engineering and Environmental Laboratory (INEEL) Boron Neutron Capture Therapy (BNCT) Research Program for calendar year 1996. Contributions from the individual investigators about their projects are included, specifically, physics: treatment planning software, real-time neutron beam measurement dosimetry, measurement of the Finnish research reactor epithermal neutron spectrum, BNCT accelerator technology; and chemistry: analysis of biological samples and preparation of {sup 10}B enriched decaborane.
The document represents a guide for the external decontamination of persons accidentally radio contaminated due to the use, production or transport of radioactive materials. The general conditions, from the medical point of view, to be kept in mind, in the event of accidental overexposures as decontamination treatment and the handling of samples are detailed throughout report. The external contamination without injury in skin or with wound its considered. The distribution of measures and responsibilities for the therapy of the irradiated patients with radioactive materials are enumerated. The preparations of decontaminate solutions are detailed in this work. Moreover, forms for the reception, physical evaluation of the patient and external contamination are presented. (author)
We demonstrate the possibility to fabricate arrays of pores oriented perpendicular and parallel to the top surface of the ZnSe nanotemplate. The control of material conductivity allows one to produce porous ZnSe samples with the mean pore diameter and characteristic skeleton wall thickness from several hundreds of nanometers to about 15 nm. In addition, electrochemical treatment of ZnSe single crystals using photoresist masks allows one to prepare buried porous structures with pores directed parallel to the top template surface, which is especially important for photonic applications.
The decontamination of the urban building surfaces, based on the covering of clay suspensions, has been studied. Contaminated samples for test purpose were prepared by application of radioactive solution which was extracted from the soil of 2 km zone of the Chernobyl Nuclear Power Plant(ChNPP). The cation converting conditions of clay suspensions were determined by the experiments of swelling and stability of the suspensions. According to the experimental results, the most effective clay suspension was the NH{sub 4}-type which had a 7.1 of decontamination factor(DF) on Cs and 4.5 of DF on total nuclides after 3 times covering on slate.
Use of hydrogen absorbing alloys in various practical applications is always connected with the problem of production of starting alloys. The transition from laboratory samples to small-scale production involves the change of furnace and its operation mode and this has an effect on the preparation method of mixture of starting metal. Also, for some applications such as thermosorption compressors the exact values of thermodynamical parameters of reaction are needed. In the present work we present the results of investigation of series Laves phase hydrogen-absorbing alloys which can be promising in for use in different devices. 1 ref.
We present a samplepreparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +/- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +/- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by ...
We present a samplepreparation method for measuring magnesium in individual whole lymphocytes by electron probe X-ray microanalysis. We use Burkitt's lymphoma cells in culture as the test sample and compare X-ray microanalysis of individual cells with atomic absorption analysis of pooled cell populations. We determine the magnesium peak-to-local continuum X-ray intensity ratio by electron probe X-ray microanalysis and calculate a mean cell magnesium concentration of 39 +- 19 mmol/kg dry weight from analysis of 100 cells. We determine a mean cell magnesium concentration of 34 +- 4 mmol/kg dry weight by atomic absorption analysis of pooled cells in three cell cultures. The mean cell magnesium concentrations determined by the two methods are not significantly different. We find a 10% coefficient of variation for both methods of analysis and a 30% coefficient of variation in magnesium concentration among individual cells by ...
The microbial transport simulator (MTS) is a three-dimensional, three-phase, multiple-component numerical model that permits the study of the transport of microorganisms and nutrients in porous media. Microbial parameters incorporated into MTS include: Microbial growth and decay, microbial deposition, chemotaxis, diffusion, convective dispersion, tumbling, and nutrient consumption. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The model`s mathematical formulations and preparation procedures of data files for conducting simulations using MTS are described. A general background of microbial transport simulation is given in Section I and the governing equations, mechanisms, and numerical solutions of MTS are given in Section II. Explanations for preparing an input data file with reservoir and microbial transport data are described in ...
In this paper, we report the electrochemical characteristics of a novel cathode material, Li{sub 2}CoPO{sub 4}F, prepared by solid-state reactions. The solid-state reaction mechanism involved in synthesizing the Li{sub 2}CoPO{sub 4}F also is analyzed in this paper. When cycled between 2.0 V and 5.0 V during cyclic voltammetry measurements, the Li{sub 2}CoPO{sub 4}F samples present one, fully reversible anodic reaction at 4.81 V. When cycled between 2.0 V and 5.5 V, peaks occurring at 4.81 V and 5.12 V in the first anodic scan evolved to one broad oxidative, mound-like pattern in subsequent cycles. Correspondingly, the X-ray diffraction (XRD) pattern of the Li{sub 2}CoPO{sub 4}F electrode discharged from 5.5 V to 2.0 V is slightly different from the patterns exhibited by a fresh sample and the sample discharged from 5.0 V to 2.0 V. This difference may correspond to a structural relaxation that appears ...
The design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal conductivity results show that the values are affected both by the particle size and the sample density. Thermal ...
Superconducting rf cavities are increasingly used in accelerators. Gradient is a parameter of particular importance for the ILC. Much progress in gradient has been made over the past decade, overcoming problems of multipacting, field emission, and breakdown triggered by surface impurities. However, the quenching limit of the surface magnetic field for niobium remains a hard limitation on cavity fields sustainable with this technology. Further exploration of materials and preparation may offer a path to surpassing the current limit. For this purpose, we have designed a resonant test cavity. One wall of the cavity is formed by a flat sample of superconducting material; the rest of the cavity is copper or niobium. The H field on the sample wall is 75% higher than on any other surface. Multipacting is avoided by use of a mode with no surface electric field. The cavity will be resonated through a coupling iris with high-power rf ...
Fe-sheathed MgB{sub 2} tapes with cheap stearic acid, Mg stearate and Zn stearate doping were prepared through the in situ powder-in-tube method. It is found that J{sub c}, H{sub irr} and H{sub c2} were significantly enhanced by doping. Compared to the pure tapes, J{sub c} for all the doped samples was improved by more than an order of magnitude in a high-field regime. At 4.2 K, the transport J{sub c} reached 2.02 x 10{sup 4} A cm{sup -2} at 10 T for the Zn stearate doped tapes and 3.72 x 10{sup 3} A cm{sup -2} at 14 T for the stearic acid doped samples, respectively. Moreover, at 20 K, H{sub irr} for the Zn stearate doped tape achieved 10 T, which is comparable to that of the commercial NbTi at 4.2 K. The improvement of J{sub c}-H properties in doped samples can be attributed to the increase of H{sub c2} resulting from the incorporation of C atoms into the MgB{sub 2} crystal lattice as well as a high ...
SiO/sub 2//Si samplesprepared in 2% and 4% HCl/O/sub 2/ mixtures at 1200/sup 0/C have been annealed in H/sub 2/O/N/sub 2/ ambients at 1200/sup 0/C. The anneals ranged up to 16 hrs in ambients with 4 or 40 ppM H/sub 2/O in N/sub 2/. Rutherford backscattering measurements have been made to determine the amount and location of Cl incorporated in these samples. A linear loss of Cl with annealing time is found for all samples. Changes in the distribution of Cl near the SiO/sub 2//Si interface are found. These changes are interpreted in terms of morphological changes in the third (Cl containing) phase. A significant effect of the H/sub 2/O content of the N/sub 2/ ambient is observed.
To examine and evaluate the predominant and common etiologic agent(s) of urinary tract infection (UTI) in Sukkur city and to determine their current antibiotic susceptibility/resistance trends. Nine hundred sixty six patients out of 1430 abnormal urine reports (showing significant abnormalities such as protein, pus, red cells) were asked to give second sample. The urine samples were examined by both urine test strip (Combur 10 Test, Roche) and microscopically (wet preparation) followed by culture and sensitivity. The culture sensitivity was done on urine samples of which bacterial numbers were estimated as more than 105CFU. The study was conducted at Safeway Diagnostic and Research Laboratory Sukkur and the Department of Microbiology, Shah Abdul Latif University Khairpur, Sindh from March 2001 to March 2003. Eight hundred fifty-two (88.2%) showed Escherichia spp followed by Klebsiella spp (6.9%) and ...
Trichlorfon is an organophosphorus insecticide, which is extensively being used for protection of fruit crops. Trichlorfon is a thermal labile compound, which cannot be easily determined by gas chromatography (GC) and has no suitable group for sensitive detection by high performance liquid chromatography (HPLC). In this study, a {sup 31}P nuclear magnetic resonance ({sup 31}P NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of {sup 31}P NMR spectroscopy has been performed in the presence of an internal standard (hexamethylphosphoramide). Limit of detection (LOD) for this method has been found to be 55 mg L{sup -1}, without any samplepreparation, and the linear working range was 150-5500 mg L{sup -1}. Relative standard deviation (R.S.D.%) of the method for three replicates within and between days was obtained {<=}9%. The average recovery efficiency was approximately 99-112%. This ...
The objective this work was to evaluate the gamma radiation processing for elimination of organic contaminants on industrial wastewater. Standard samples with 17 hydrocarbons (acetophenone, anisole, benzene, chlorobenzene, cyclohexanone, N, N-dimethylaniline, phenol, naphtalene, 1-chloronaphtalene, n-octadecane, p-nitrotoluene, toluene, tetrachloroethane, tetramethylbenzene, n-undecane, m-xylene and o-xylene) was preparated in hexane with total concentration of 1 #mu# g/ #mu# l which was analyzed by gas chromatography. Other sample with the same concentration of these hydrocarbons in acetone was used to contaminate water samples, which were irradiated with gamma radiation from Co-60 between doses 5.0 to 20.0 KGy and dose rate of 1.162 KGy/h. The activity of source was 1470 Ci. Percents destruction of hydrocarbons were: 79.76 % to 5.0 KGy, 85.97 % to 7.5 KGy, 86.24 % to 10.0 KGy, 86.72 % to 12.5 KGy, ...
Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectric and anti-ferroelectric PLZT with a variety of species or combinations of species. These included Ne, O, Ni, Ne/Cr, Ne/Al, Ne/Ni, Ne/O, and Ni/O, at a variety of energies and fluences. An indium-tin oxide (ITO) electrode coating was designed to give a balance of high conductivity and optical transmission at near uv to near ir wavelengths. Samples were characterized for photosensitivity; implanted layer thickness, index of refraction, and density; electrode (ITO) conductivity; and in some cases, residual stress curvature. Thin film anti-ferroelectric PLZT was deposited in a preliminary experiment. The structure was amorphous with x-ray diffraction showing the beginnings of ...
An energy analyzer has been constructed and operated in UHV for the purpose of analyzing the energy of neutral atoms scattered from solid surfaces. The analyzer consists of a LiF single crystal located at an angle close to the normal to the sample crystal so that the diffraction pattern obtained by scanning the LiF crystal yields the energy of the scattered atoms. Two designs which have been used are described. The temperature of both sample and analyzer crystal is near 20 K and once cleaned they can be maintained in the state of initial preparation for many weeks. The sample was a (001) Cu surface in this case. Such an energy analyzer can only be used, in most cases, for He atom scattering although Ne atoms could be used if the scattered intensities were adequate. The detector developed in this study is able to detect about 2 x 10"5 atoms/s. The resolution of the spectrometer depends on the incident ...
Extra-fine powdered activated charcoal has been used as stationary phase (coating layer) in solid-phase microextraction (SPME). The efficiency and reliability of the prepared device have been investigated for the extraction of some volatile organic compounds such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) from the headspace of water samples. Monitoring of the extracted compounds and further quantitative analysis of the real samples have been performed by capillary GC-FID. Effects of several factors such as temperature, addition of salt, and stirring speed on extraction efficiency and exposure time have been studied. Under optimum conditions, extraction recoveries for these compounds from 50 mL water were >95%. The calibration graphs were linear in the range 5 to 10{sup 4} pg mL{sup -1} and the detection limit for each BTEX compound was 1.5-2 pg mL{sup -1}. The results obtained by use of this porous layer ...
This presentation discussed common mechanisms for procuring wind energy in Canada. Mechanisms included renewable portfolio standards (RPSs); offsets; tax subsidies; financial subsidies; command and control mechanisms; and request for proposals (RFPs). A layered approach is required to avoid reliance on any single mechanism. RPSs require a certain minimum percentage of energy to come from renewable sources and aim to encourage the local development of renewable energy. RPSs are market-friendly and often result in the creation of tradable renewable energy credits (RECs) used for compliance purposes. RPSs work in parallel with cap and trade, baseline, and credit and carbon tax systems. RFPs target the lowest price offering, a practice which has often resulted in lower rates of return, high attrition, and a failure to attribute market prices to green attributes. It was concluded that RPSs work with a variety of policy frameworks and encourage the development of ...
Work on this coke oven gas cleaning demonstration project (CCT-II) this quarter has been focused on Phase IIB tasks, and include engineering, procurement, construction, and training. Additionally, plans for changes in the operating schedule of the coke plant that affect the demonstration project are described. Engineering efforts are nearly complete. Remaining to be finalized is an assessment of electrical heat tracing/insulation needs for pipe lines, assessment of fire protection requirements, and instrument modifications. Procurement of all major equipment items is complete, except for possible additions to fire fighting capabilities. Major focus is on expediting pipe and structural steel to the project site. Civil construction is complete except for minor pads and bases as required for pipe supports, etc. Erection of the hydrogen sulfide and ammonia scrubber vessels is complete. Installation of scrubber vessel internals is underway. A ...
All of the project work since the previous report has been on Phase 2B tasks. Therefore, this quarterly progress report summarizes the period's activities in Engineering, Procurement and Civil Construction. Engineering is 95% complete, but revisions and changes are still being incorporated particularly in the Instrument and Electrical areas. Procurement has only valves 4 in. and above yet to order to complete all major items purchased. The scheduled material curve was based on the original estimate of the job. The projected curve reflects the previous month's estimate. Construction of civil work is proceeding according to schedule in the field. The initial bid packages for the Mechanical General Contractor portion of the work have been reviewed and evaluated. Order placement is scheduled for the end of July. The Electrical package is due back from the bidders on July 6. It requires additional evaluation by BSC and DSO and will ...
Lawrence Livermore National Laboratories` Zephyr System provides a showcase for the ways in which emerging technologies can help streamline procurement processes and improve the coordination between participants in engineering projects by allowing collaboration in ways that have not been possible before. The project also shows the success of a highly pragmatic approach that was initiated by the end user community, and that intentionally covered standard situations, rather than aiming at also automating the exceptions. By helping push purchasing responsibilities down to the end user, thereby greatly reducing the involvement of the purchasing department in operational activities, it was possible to streamline the process significantly resulting in time savings of up to 90%, major cost reductions, and improved quality. Left with less day-to- day purchasing operations, the purchasing department has more time for strategic tasks such as selecting and pre-qualifying new ...
Improved test techniques are needed for evaluating the inherent stability of middle distillate fuels both in surveillance and in procurement activities. A project was initiated to define and evaluate the contributing conditions leading to the formation of deleterious products in accelerated aging tests of middle distillate fuels and to relate these results to an experimental definition of more repeatable/reliable middle distillate fuel stability test technique(s). A literature search was conducted to provide a list of stability test techniques and their interpretations which could be used in a correlative middle distillate fuel stability test program. For this program, seven accelerated stability tests were chosen and evaluated using a set of six test fuels. The test techniques were selected to represent a wide variety of test conditions, including temperature, aging time, and oxygen availability. These six test fuels were purposely chosen to represent a wider ...
Lawrence Livermore National Laboratory (LLNL) is implementing an Internet-based process pilot called `Zephyr` to streamline engineering and commerce using the Internet. Major benefits have accrued by using Zephyr in facilitating industrial collaboration, speeding the engineering development cycle, reducing procurement time, and lowering overall costs. Programs at LLNL are potentializing the efficiencies introduced since implementing Zephyr. Zephyr`s pilot functionality is undergoing full integration with Business Systems, Finance, and Vendors to support major programs at the Laboratory.
Examines thermal coal demand in Japan covering: trends in energy demand; long-term outlook for energy supply and demand; coal-fired power development plan and the outlook for steam coal demand; and the prospects for Asian steam coal demand and coal procurement. Total energy consumption is expected to increase by 1.0% per annum to 2000 and thereafter 0.9% per annum until 2010. This is based on the assumption that measures to encourage energy conservation and improve energy efficiency are implemented. 3 figs., 2 tabs.
The U.S. Support Program to International Atomic Energy Agency (IAEA) Safeguards (USSP) was established in 1977 to transfer US technology and expertise to assist the IAEA Department of Safeguards because its limited budget and scope would not allow for R&D activities and the procurement of specialized or customized equipment. Over the years, the USSP and the Department of Safeguards have worked together continuously to develop and improve processes for requesting, selecting, and managing projects that support the Safeguards verification mission. This paper will discuss the main USSP processes for accepting and processing Safeguards requests, and managing and reporting task progress.
The LHC is designed to provide proton beams of 7 TeV and nominal luminosity of 10**34 cm**-2s**-1. This objective is achieved at an affordable cost by pushing all major collider components to the limits of technology, by upgrading the existing CERN accelerators and infrastructure, and by involving the technical expertise, resources and dedication of accelerator laboratories world-wide. Following a decade of intensive R&D and technical validation of major collider systems, the LHC construction is now fully underway. Major industrial contracts have been awarded and are in execution for the procurement of the magnet, cryogenics and other systems. In this report, the status of the design and construction of the major LHC systems is presented.
Four major reasons why municipal resource recovery operations are uneconomical are analyzed. These reasons are: alternative municipal waste disposal methods are artificially underpriced when the costs of meeting modern environmental standards are considered; high capital costs related to the procurement of resource recovery systems and the marketing of recovered resources; uncertainties associated with the costs and performance of resource recovery technologies; and construction and operating risks of municipal waste resource recovery systems. If resource recovery is to become economical, purchasers of plants must develop innovative process designs and equipment and formulate new operating and maintenance procedures. (1 photo)
The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.
The objective of the research was to develop a procurement method for small-diameter pulpwood based on chain-flail delimbing-debarking method. The study consisted of four parts: Development of the chain-flail delimbing-debarking method (based on Peterson Pacific DDC 5000 device); Combined chain-flail delimbing and drum-debarking; Processing and procurement of the chain-flail delimbing chips and; Intensifying of the timber debarking in chain-flail delimbing. The project was coordinated by Metsaeteho, and it was carried out as cooperation between Metsaeteho, the Finnish Forest Research Institute (METLA), VTT Energy, Pertti Szepaniak Oy and Enso-Gutzeit Oy. A calculation model, by which it is possible to determine the costs of pulpwood chips and fuel-rawmaterials formed beside the pulpwood chips while using different kinds of procurement methods and chains, was developed for chain-flail delimbing-debarking-chipping method ...
porous silica ceramics were prepared(with HCL catalyst)using H{sub 2}O/TEOS molar ratios of 2.6-59.0, with the EtOH/TEOS ratio fixed. After preparing 9 kinds of sol, the followings were investigated; measurement of the gelation time, thermal analyses by TG/DTA, property analyses of the intermediates by FT-IR and X-ray diffractometry with dried samples, analyses of SiO{sub 2} polymer by FT-IR, the investigation of specific surface area and pore size distribution by N{sub 2}-adsorption isotherm, and structural change of SiO{sub 2} polymer and pore morphology by TEM observation, with samples heat-treated to 500 deg. C. In the concentrations of investigated compositions and catalyst, gelation time showed a minimum at ca. 11 moles of water per one mole of TEOS, the highest degree of polymerization at ca.8-18 moles, and the largest specific surface area at ca. 11 moles, which means that the polymerization ...
The Fermi National Laboratory (Fermilab) operates the Tevatron proton-antiproton collider at a center-of-mass energy of {radical}s = 1.96 TeV, the is therefore the only collider which is today able to produce the heaviest known particle, the top quark. The top quark was discovered at the Tevatron by the CDF and D0 collaborations in 1995. At the Tevatron, most top quarks are produced via the strong interaction, whereby quark-antiquark annihilation dominates with 85%, and gluon fusion contributes with 15%. Considering next-to-leading order (NLO) contributions in the cross section of top-antitop quark production, leads to a slight positive asymmetry in the differential distribution of the production angle {alpha} of the top quarks. This asymmetry is due to the interference of certain NLO contributions. The charge asymmetry A in the cosine of {alpha} is predicted [14] to amount to 4-6%. Information about the partonic rest frame, necessary for a measurement of A in the observable cos ...
Aqueous deoxyhemoglobin solutions (2 mg/ml) were gamma-irradiated by a "6"0Co source in the presence of methanol, ethanol, 1-butanol and t-butanol under N_2O or argon. The effects of the interaction of the particular alcohol radical species with hemoglobin were determined according to the detected spectral alterations in the visible range. The amounts of stable final products in the form of methemoglobin (MetHb) and the sum of hemichromes and cholehemichromes (Hemichr) were estimated in irradiated preparations. For preparations irradiated under N_2O, the radiation yield for MetHb formation was three-fold lower in the presence of ethanol and 1-butanol [G(MetHb) = 0.33[ compared with preparations irradiated in the presence of t-butanol or without alcohol [G(MetHb) = 1.00[. The yield of hemichromes and cholehemichromes in preparations irradiated under N_2O increased in the order: ethanol (G = 0.38), ...
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 ...
Superconducting MgB{sub 2} samples were prepared by the sintering of a mixture of fine Mg (or Mg alloy) powder produced by gas-atomization and B powder. The single MgB{sub 2} phase with a superconducting onset temperature of 38 K was obtained by sintering at 1073 K for the pure Mg or AZ31 alloy powders. In the case of AZ31, the superconducting MgB{sub 2} was obtained by sintering at a low temperature of 873 K for 50 h although a long sintering time of 100 h is needed to obtain a single MgB{sub 2} phase for Mg powder. This indicates that the AZ31 alloy enhances a formation rate of superconducting MgB{sub 2} at the low temperature through the formation of the partial melting phase. Thus, the gas-atomized fine Mg or AZ31 alloy powders are useful for preparation of a superconducting MgB{sub 2} and in particular AZ31 alloy is effective for the low temperature fabrication of MgB{sub 2}. (orig.)
The identification of crystallographic phases in the scanning electron microscope (SEM) has been limited by the lack of a simple way to obtain electron diffraction data of an unknown while observing the micro structure of the specimen. With the development of Charge Coupled Device (CCD) based detectors, backscattered electron Kikuchi patterns (BEKP), alternately referred to as electron backscattered diffraction patterns (EBSP), can be easily collected. Previously, BEKP has been limited to crystallographic orientation studies due to the poor pattern quality collected with video rate detector systems. With CCD detectors, a typical BEKP can now be acquired from a micron or sub-micron-sized crystal using an exposure time of 1-10 seconds with an accelerating voltage of 10-40 kV and a beam current as low as 0.1 nA. Crystallographic phase analysis using BEKP is unique in that the properly equipped SEM permits high magnification images, BEKP`s, and elemental information to be collected from ...
The design of a gaging head for a portable radionuclide X-ray fluorescence analyzer is described. The gaging head is designed as a construction unit system which enables the application of lateral reflexion geometry as well as of coaxial geometry. It is designed so that adjustment from one geometry to the other is labour and time saving. The selection of characteristic radiation is performed by a couple of Ross' differential filters. These filters are prepared by a novel technique developed by our laboratory. The filter exchange is effected by the longitudinal move of the couple of filters encapsulated in a holder. The shift of the filters is controlled by means of a triggering mechanism situated in the body of the gaging head handle. This design makes is possible to handle the gaging head during measurements with one hand. A simple interchange of the absorption filter for the transmissive filter allows the operator to avoid any unwanted shift of the head during ...
Buried silicon carbide (SiC) microstructures with lateral dimensions in the #mu#m range were formed by high-dose projection of 1.5 MeV C"2"+ ions in Si(100) at different doses and temperatures and subsequent annealing for 10 h at 1250 deg. C. Sections of individual SiC microstructures were prepared for cross-sectional transmission electron microscopy (TEM) analysis using a focused ion beam (FIB). Besides the possibility to select an individual microstructure, the FIB technique has the advantage of producing specimen foils of uniform thickness. Therefore, it was possible to map the carbon concentration of microstructures by energy filtered TEM (EFTEM) using the C_K absorption edge without the need of any sample thickness correction. Local overstoichiometric (>50%) carbon concentrations are shown to be correlated to the formation of an amorphous phase in the SiC and to significant swelling visible at the Si wafer surface 2 #mu#m above.
Spices and packaging materials were exposed to gamma irradiation at a dose of 10 KGy. Luncheon was prepared with irradiated or non-irradiated spices. Prepared luncheon was packaged in irradiated or non-irradiated packaging materials. Packaged luncheon was treated with 2 KGy. Treated and untreated packaged luncheon were kept in a refrigerator (1-4 Centigrade) for 12 months. Microbiological, nutritive and chemical characteristics of luncheon were evaluated after processing and during storage; whereas, sensory quality was evaluated only after irradiation. Gamma irradiation decreased the microorganisms counts of spices, packaging materials and packed luncheon and increased the shelf-life of packaged luncheon products. No major differences in moisture, protein, fat, ph value, total acidity, lipid peroxide and volatile basic nitrogen were observed due to irradiation. Sensory evaluation showed that all the combination treated luncheon were acceptable ...
A series of spinel Li4Ti5O12 samples were synthesized via a composite molten-salt method (CMSM) using the mixtures of LiCl and KCl with different L values (L is defined as the molar ratio of LiCl:KCl) as the reaction media. It is found that the melting point of the composite molten salt can effectively influence the formation of particles, and leads to different electrochemical performances of the as-prepare Li4Ti5O12. The investigations of X-ray diffraction (XRD), particle size distribution (PSD), Brunauer-Emmet-Teller (BET) surface area, and scanning electron microscopy (SEM) indicate that the as-prepared Li4Ti5O12 with L = 1.5 is a pure phase, and has uniform homogeneous octahedral shape particles, rather narrow PSD, and high BET surface area. Electrochemical tests show that the optimized Li4Ti5O12 with L = 1.5 has an initial discharge capacity of 169 mAh g-1 and an initial charge-discharge efficiency of 94% at 0.2 C ...
A series of spinel Li4Ti5O12 samples were synthesized via a composite molten-salt method (CMSM) using the mixtures of LiCl and KCl with different L values (L is defined as the molar ratio of LiCl:KCl) as the reaction media. It is found that the melting point of the composite molten salt can effectively influence the formation of particles, and leads to different electrochemical performances of the as-prepare Li4Ti5O12. The investigations of X-ray diffraction (XRD), particle size distribution (PSD), Brunauer-Emmet-Teller (BET) surface area, and scanning electron microscopy (SEM) indicate that the as-prepared Li4Ti5O12 with L=1.5 is a pure phase, and has uniform homogeneous octahedral shape particles, rather narrow PSD, and high BET surface area. Electrochemical tests show that the optimized...
Dye-sensitized solar cells (DSSCs) based on anatase TiO2 hollow spheres (TiO2HS)/multi-walled carbon nanotubes (CNT) nanocomposite films are prepared by a directly mechanical mixing and doctor blade method. The preparedsamples are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy and N2 adsorption-desorption isotherms. The photoelectric conversion performances of the DSSCs based on TiO2HS/CNT composite film electrodes are also compared with commercial-grade Degussa P25 TiO2 nanoparticles (P25)/CNT composite solar cells at the same film thickness. The results indicate that the photoelectric conversion efficiencies () of the TiO2HS/CNT composite DSSCs are dependent on CNT loading in the electrodes. A small amou...
The texture influence on tensile tests of AZ31, one of the common Mg alloys, has been studied. Starting material was a rectangular extruded bar, which has a strong texture. Due to the preparation of three tensile samples with 0 , 45 , 90 to the extrusion direction, the initial bar texture influences differently on the mechanical behaviour under tensile load. This results in a variation of the yield strength (90 MPa and 175 MPa) the ultimate tensile strength (250 MPa - 278 MPa) and the final texture. Experimental texture analysis was completed by texture simulations using the VPSC-model (visco plastic self-consistent). The good agreement between experimental and simulated pole figures allows the determination of the activated deformation modes related to the initial texture. (orig.)
Antibacterial activity of Transition metals (Mn, Co) doped ZnO nanopowders prepared by a DC thermal plasma method against Escherichia coli and Staphylococcus aureus are investigated. The phase and morphology studies have been carried out by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. All the samples of the present investigation are found to have hexagonal wurtzite structure and crystallite sizes are found to vary from 25nm to 30nm. Our bacteriological study showed the enhanced antibacterial activity of transition metals doped ZnO nanoparticles than undoped ZnO indicating the great potential of ZnO nanoparticles in relevant clinical and biomedical applications.
We have investigated the superconducting and metallurgical properties of the ternary compounds RPd_2Si_2 and RRh_2Si_2 with R = Y, La, and Lu. All RPd_2Si_2 compounds and LaRh_2Si_2 were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases can easily mask the intrinsic (stoichiometric ratio 1:2:2) intermetallic-compound properties. Two sample-preparation techniques, viz., single crystals and off-stoichiometry, were utilized to establish where bulk superconductivity occurs. The type-I behavior of these compounds is explained with an analogous model as is used for the heavy-fermion superconductors CeCu_2Si_2 and URu_2Si_2.
Research highlights: ? Reports a high protection system for the alloy in corrosive environment. ? Describes an interfacial process with self-healing properties. ? Reports the influence of substrate pre-treatment in the coating performance. - Abstract: In this paper the interface of poly(vinylidene fluoride) coatings prepared by the dip coating method and HF-treated AZ31 magnesium alloy was evaluated. The best performance of this system in corrosion tests compared to ground, as-received and acetic acid cleaned substrates is related to an acid-base interaction at the interface and to interfacial reactions which resulted in a self-healing process. The protectiveness of the samples was investigated using impedance and immersion tests while the coating morphology and interface stability were investigated by scanning electron microscopy, X-ray photoelectron spectroscopy and adhesion tests.
Three-dimensional porous Sn thin film electrodes were prepared by electroless deposition on copper foam, then its morphology and electrochemical property were studied by means of scanning electron microscope (SEM), X-ray diffraction (XRD), electrochemical cycling test and cyclic voltammetry (CV). The porous framework and micro-holes have shown a great structure advantage in restricting severe volume changes when the Sn thin film was employed as anode for lithium-ion battery. The film electrode of sample C with an initial capacity of 676 mAh g{sup -1} showed good cycle performance displayed by retaining a capacity of 313 mAh g{sup -1} after 100 cycles.
Magnetic fluids (MFs), prepared by chemical co-precipitation followed by double layer steric and electrostatic (combined) stabilization of magnetite nanoparticles dispersed in water, are presented. Several combinations of surfactants with different chain lengths (lauric acid (LA), myristic acid (MA), oleic acid (OA) and dodecyl-benzene-sulphonic acid (DBS)) were used, such as LA+LA, MA+MA, LA+DBS, MA+DBS, OA+DBS, OA+OA and DBS+DBS. Static light scattering, transmission electron microscopy, small angle neutron scattering, magnetic and magneto-rheological measurements revealed that MFs with MA+MA or LA+LA biocompatible double layer covered magnetite nanoparticles are the most stable colloidal systems among the investigated samples, and thus suitable for biomedical applications.
The laser cooling and trapping of ultracold neutral dysprosium has been recently demonstrated using the broad, open 421-nm cycling transition. Narrow-line magneto-optical trapping of Dy on longer wavelength transitions would enable the preparation of ultracold Dy samples suitable for loading optical dipole traps and subsequent evaporative cooling. We have identified the closed 741-nm cycling transition as a candidate for the narrow-line cooling of Dy. We present experimental data on the isotope shifts, the hyperfine constants A and B, and the decay rate of the 741-nm transition. In addition, we report a measurement of the 421-nm transition's linewidth, which agrees with previous measurements. We summarize the laser cooling characteristics of these transitions as well as other narrow cycling transitions that may prove useful for cooling Dy.
The dual characteristics in the performance of polymers in wood-polymer composites systems have been pursued with regard to the resolution of mechanical anisotropy of wood and the improvement in dimensional stability. The objective of the present study is to pursue the polymerization mechanism in wood under electron beam irradiation and the temperature dependence of polymer-wood interactions induced at various levels of higher order structure of wood in order to understand the polymer performance. Veneers used in the study were of rotary-cut beech (Fagus crenata Blume) 0.65 mm thick. All samples were oven-dried in vacuo at 80/sup 0/C for 30 hr. The monomers used in the study were methyl methacrylate, styrene, acrylic acid, acrylonitrile, and unsaturated polyester. Experimental details are given. Results are given and discussed.
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 samplepreparation 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...
Twelve powders of TiO_2-Y_2O_3-ZrO_2 solid solution of the methodically changed composition were prepared by a coprecipitation-calcination technique. After mixing with phenol-formaldehyde resin, the powders were calcinated for 2 hours at 1200"oC in vacuum. The resultant composite powders contained TiC and non-reacted carbon. Green compacts were sintered in vacuum at 1500"oC for 2 hours. A temperature increase was stopped at 1200"oC to react remains of carbon. There were two carbides in the composites TiC and ZrC. TiC non-stoichiometry depended on carbon content in the system. Phase composition of the depended on of titania and yttria in zirconia solid solution. The majority of the samples showed two tetragonal zirconia phases differing in lattice parameter and tetragonality. (author)
The biological treatment process was selected by Gaz de France (GDF), the French national gas utility, for the de-pollution of an old gas works where the main pollutants are coal tars containing polycyclic aromatic hydrocarbons. Microorganism-based biological treatment techniques may involve bio-reactors, static ground knolls (where oxygen is brought through drains) and dynamic knolls (where oxygenation is carried out by turning up the soil). Issues on sampling, sorting, process testing, site preparation, process control, etc. are reviewed
The first automated method for the determination of mexiletine hydrochloride - an antiarrhythmic agent - is reported. The method is based on the reaction of the analyte with o-phthalaldehyde (OPA) in the presence of sulfite in basic medium using a sequential injection (SI) manifold. The reaction product was monitored spectrofluorimetrically (lex=350nm/lem=446nm). A simple and effective on-line dilution approach was adopted in order to expand the linearity and apply the method to assay, dosage uniformity and dissolution tests with minimum samplepreparation. Chemical (pH, amount concentrations of OPA and sulfite) and instrumental variables (temperature, flow rate, injection volumes, etc.) that affected the determination were studied. The developed assay was validated in terms of linearity, ...
Synthesis, morphology, structural and optical characteristics of SiC NWs and SiC/C nanocomposites with an inverse opal lattice have been investigated. The samples were prepared by carbothermal reduction of silica (SiC NWs) and by thermo-chemical treatment of opal matrices (SiC/C) filled with carbon compounds which was followed by silicon dioxide dissolution. It was shown that the nucleation of SiC NWs occurs at the surface of carbon fibers felt. It was observed three preferred growth direction of the NWs: [111], [110] and [112]. HRTEM studies revealed the mechanism of the wires growth direction change. SiC/C- HRTEM revealed in the structure of the composites, except for silicon carbide, graphite and amorphous carbon, spherical carbon particles containing concentric graphite shells (onion-like particles).
Abstract Plant metabolomics has been well established and applied across multiple fields including medicine, biotechnology, and environmental sciences in the post-genomic era. The Chenopodiaceae C3 halophyte Suaeda salsa is the most important plant species in the vegetation of saline soil and even intertidal zone in the Yellow River Delta, which is economically consumed as food, widely used as a bioindicator of environmental stresses (salinity, drought, and pollution) and typically applied for the phyto-remediation of degraded wetland. However, no global studies have been focused on the metabolic profile of this halophyte which is widely applied in environment related research areas. In metabolomics, the first crucial step is the preparation of plant samples. In this work, several strategi...
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of samplepreparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of samplepreparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
By applying lock-in thermography imaging, light-beam-induced current imaging, electron-beam-induced current imaging at different stages of samplepreparation, and infrared light microscopy in transmission mode, the physical nature of the dominant material-induced shunts in multicrystalline solar cells made from p-type silicon material has been investigated. It turns out that these shunts are due to silicon carbide (SiC) filaments, which grow preferentially in grain boundaries and cross the whole cell. These filaments are highly n-type doped, like the emitter layer on the surface of the cells. They are electrically connected both with the emitter and with the back contact, thereby producing internal shunts in the solar cell.
Consideration is given to the data, demonstrating the effect of ion radiation on strength characteristics of ionic crystals, presented by magnesium oxide. Crystals, prepared in the form of plates, were irradiated by Si"+, Fe"+, C"+ ions by the dose of 10"1"6-10"1"7 ion/cm"2 at room temperature in vacuum. The following characteristics were investigated: dislocation density, microhardness, crack resistance. Investigation of dislocation structure showed, that dislocation density in irradiated sample was 2-3 times higher, as compared to nonirradiated one. Sufficient increase of fracture viscosity of MgO crystals was revealed. It can be conditioned by occurrence of compression stresses in the surface layer, decelerating crack formation and propagation.
In this paper, 0.75Pb(Fe2/3W1/3)O3-0.25PbTiO3-0.15 wt% MnO (0.75PFW-0.25PT-0.15 wt% MnO) ceramics are synthesized by two different methods, the conventional direct oxide synthesized (DS) method and two-step indirect synthesized (IS) method. The low-field dielectric responses are investigated by using the empirical law, the Curie-Weiss law, the modified-Landau theory and the spin-glass model. Due to the IS method, the lattice structure and the grain structure of the samples are changed. Furthermore, the dielectric properties are evidently modified. It is suggested that the ordering degree of B-site cations is enhanced by using the IS synthesized method.
Nd{sub 40}Fe{sub 30}Al{sub 10}Co{sub 15}B{sub 5} alloys were fabricated by high energy ball milling method under various conditions. Microstructure of the alloys was investigated by X-ray diffraction and electron microscopy techniques. Magnetic properties were characterized by hysteresis and thermomagnetic measurements. The high coercive fields up to 2.36 T have been observed on the samples consisting of Nd{sub 2}(Fe,Co,Al){sub 14}B, Nd{sub 6}(Fe,Co,Al){sub 14} and Nd crystallites imbedded in a residual amorphous matrix.
Actinidia deliciosa endosperm-derived callus culture is stable over a long period of culture. This system was used to investigate the ultrastructure of extracellular matrix occurring in morphogenic tissue. Specimens were prepared by different biological techniques (chemical fixation, liquid nitrogen fixation, glycerol substitution, critical-point drying, lyophilization) and observed by scanning electron microscopy (SEM). Fresh and wet samples were analyzed with the use of environmental scanning electron microscopy (ESEM). Extracellular matrix was observed on the surface of cell clusters as a membranous layer or reticulated network, shrunken or wrinkled, depending on the procedure. Generally, shrunken membranous layers with a globular appearance and fibrils were noted after critical-point d...
This article describes the chemical preparation of petroleum additives of the MASK type from samples of concentrated alkylsalicylic acids. The obtained additives contain high contents of calcium alkylsalicylate and respective total alkalinities of 156, 131, and 130 mg KOH/g. Sodium alkylsalicylate concentrates, obtained in the form of an aqueous acetone solution, were converted to alkylsalicylic acids by interaction with hydrochloric acid. The solvent was removed from the upper and lower layers by distillation, and the resulting products were analyzed by liquid chromatography. Service tests were performed on a model formulation of the additive in M-11 oil in a Petter AV-1 test stand unit in comparison with commercial MASK additive. The results indicate that the model additive formulation gives approximately the same corrected piston fouling ratings as the commercial additive.
We report significant enhancement in superconducting properties of yttrium substituted Ce1-xYxOFFeAs superconductors. The polycrystalline samples were prepared by two step solid state reaction technique. X-ray diffraction confirmed tetragonal ZrCuSiAs structure with decrease in both a and c lattice parameters on increasing yttrium substitution (with fixed F content). With smaller ion Y in place of Ce, the transition temperature increased by 6 K. Yttrium doping also lead to higher critical fields as well as broader magnetization loops, particularly at elevated temperature.
Abstract This study investigated the effects of Maillard reaction products (MRPs) on in vitro starch hydrolysis, and in vivo blood glucose responses in mice. Four MRPs of various dextrose equivalents were prepared by heating a mixture of hydrolyzed rice starch and glycine at 200C for 4-min. The starch hydrolysis rates of gelatinized rice starch (GRS) decreased as the browning reaction of added MRPs increased. The hydrolysis kinetic constants of the GRS with 5% MRPs were relatively lower than that of GRS without MRPs. Blood glucose responses showed similar tendencies to the in vitro starch hydrolysis results. The activity of digestive enzymes was inhibited by the MRPs. The relative crystallinity of all MRPs (29.9-60.1%) appeared to have higher values than GRS (15.1%). The samples heated to ...
Medium-density polyethylene/multiwall carbon nanotube (MDPE/MWCNT) nanocomposites were produced by a mechanical milling method using a high-energy ball mill. The MDPE and MWCNTs were added to the ball mill at a constant 20:1 weight ratio of ball/powders and milled for 10 h to obtain polyethylene matrix nanocomposites reinforced with 0.5, 1, 2.5, and 5 weight percent of MWCNTs. To clarify the role of both MWCNT content and milling time on the morphology of MDPE, some nanocomposite samples were investigated by using a scanning electron microscope. To evaluate the role of milling on the microstructure of the nanocomposites, very thin films of MDPE/MWCNTs were prepared and studied by transmission electron microscopy. Thermal behavior of these nanocomposites was investigated by using differenti...
Amino-rich polymeric coatings are widely used in biomedical applications, since they promote adsorption of diverse biomolecules or facilitate cell growth. As a consequence, there is a growing interest in fabrication of such coatings that is focused predominantly on the optimization of the deposition process in terms of high density of primary amino groups. In addition, the nature of biomedical applications requires also sufficient stability of the films in aqueous environments. This aspect is investigated in this contribution. In particular, the effect of water and phosphate buffer saline on the coatings prepared by RF magnetron sputtering of Nylon 6,6 in Ar/N2 and N2/H2 gas mixtures is evaluated. The samples exposed to liquids are characterized by various diagnostic methods and their prop...
The incorporation of (a) Cs/Sr as simulated heat-generating isotopes contained in Purex reprocessing waste, (b) simulated actinides, and (c) simulated Purex waste in sodium zirconium phosphate (NZP) has been studied. The samples were prepared by sintering, by hot pressing and by hot isostatic pressing in metal bellows containers. The short-term chemical durability of the phosphate-based material containing Purex waste was within an order of magnitude of that for Synroc-C, as measured by 7-day MCC-1 tests at 90{degrees}C. The dissolution behavior showed evidence of re-precipitation phenomena, even after times as short as 28 days. Potential for improvement of NZP-based ceramics for HLW management is discussed. 19 refs., 4 figs., 3 tabs.
We report about the fabrication and analysis of the properties of Cr/CrO_x/Cr tunnel junctions and SET transistors, prepared by different variants of direct-writing multilayer technique. In all cases, the CrO_x tunnel barriers were formed in air under ambient conditions. From the experiments on single junctions, values for the effective barrier height and thickness were derived. For the Cr/CrO_x/Cr SET transistors we achieved minimal junction areas of 17 x 60 nm^2 using a scanning transmission electron microscope for the e-beam exposure on Si_3N_4 membrane substrate. We discuss the electrical performance of the transistor samples as well as their noise behavior.
Hierarchical TiO2 hollow spheres had been prepared based on bubble templates by a simple one-step hydrothermal method. The diameter of hollow spheres was about 700nm and the shell thickness of them was 69nm. They were composed of similar spindle- or needle-like building units. Furthermore, hydrothermal time had an important influence on the morphology and crystallinity of hollow spheres. Moreover, the UV-Vis diffuse reflectance spectra of TiO2 hollow spheres heated at 150^oC for 10h showed the strongest absorption in the UV-Vis region and the Raman spectrum demonstrated the anatase sample. Additionally, a possible formation mechanism of TiO2 hollow spheres was proposed. So this novel and simple method would provide a development direction to fabricate all kinds of inorganic hollow spheres ...
In view of no satisfactory mathematical model is presently available for the dose-response curve of immunoradiometric assay, a three parameter model based on single binding site mass action law has been derived. A curve fitting method based on similar principle of linear robust regression was designed and a software was prepared for use on IBM personal computers. Experiments revealed that the model is applicable to a variety of IRMA systems as well as to time-resolved immunofluorometric assay of hAFP. When there was outlier(s) of the calibration curve, the average bias of unknown samples obtained with this method is significantly smaller than methods using four parameter logistic model or four parameter single site mass action model.
The Si_3N_4-rich corner of the phase diagrams for neodymia and ytterbia containing sialons has been investigated by a systematic variation of the m and n values for compositions between 0.5 and 2.0 with a step size of 0.5. Samples requiring nitrides of the rare earth elements have not been prepared. Sintering has been performed at 1800 C for one hour in a nitrogen atmosphere of 1 MPa. The sintered samples were characterized by X-ray diffraction analysis to identify the crystalline phases in equilibrium with sialon. #alpha#- and #beta#-sialon, the 21R AlN polytypoid, and N-melilite M' were found in the Nd containing system. Materials with Yb showed the formation of #alpha#- and #beta#-sialon, and the AlN polytypoids 12H and 21R. The m and n values of the #alpha#-sialon phase have been calculated via their lattice parameters that were refined by a least squares routine. The occurrence and composition of the phases were used ...
Within the framework of a study on the chemical wear behaviour of sialon ceramics a range of compositions were prepared in which the alumina content was varied from 6 to 77 weight percent. The materials were hot-pressed from alumina and silicon nitride powders to a density of at least 97%. The structure and compositions of the phases occurring in these samples i.e. the O' phase, #beta#'-sialon solid solution and especially the X-phase were thoroughly characterized with respect to structure and composition using electron microprobe and transmission electron microscopy techniques. These results will be discussed in the light of earlier phase diagram studies. Some basic properties such as E-modulus and toughness were measured and related to microstructural features. E-modulus as well as toughness are at a minimum for materials with a high content of the X-phase. Oxidation of the materials was studied at 1300 deg C and 1450 deg C using weight gain ...
There is an increased emphasis on hyphenated techniques such as immunoaffinity LC/MS/MS (IA-LC/MS/MS) or IA-LC/MRM. These techniques offer competitive advantages with respect to sensitivity and selectivity over traditional LC/MS and are complementary to ligand binding assays (LBA) or ELISA's. However, these techniques are not entirely straightforward and there are several tips and tricks to routine sample analysis. We describe here our methods and procedures for how to perform online IA-LC/MS/MS including a detailed protocol for the preparation of antibody (Ab) enrichment columns. We have included sample trapping and Ab methods. Furthermore, we highlight tips, tricks, minimal and optimal approaches. This technology has been shown to be viable for several applications, species and fluids from small molecules to proteins and biomarkers to PK assays. PMID:21872661
Commercially available melter technologies were tested during 1994-95 as part of a multiphase program to test candidate technologies for vitrification of the low-level waste (LLW) stream to be derived from retrieval and pretreatment of Hanford Site tank wastes. Seven vendors were selected for Phase 1 testing to demonstrate vitrification of a high sodium content liquid LLW simulant. The tested melter technologies included four Joule-heated melters, a carbon electrode melter, a combustion melter, and a plasma melter. Various dry and slurry melter feed preparation processes were also tested. Various feed material samples, product glass samples, and process offgas streams were characterized to provide data for evaluation of process decontamination factors and material mass balances for each vitrification technology. This report describes the melter mass balance evaluations and results for six of the Phase 1 LLW melter vendor ...
In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 {mu}m). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromium and iron in the oxide layer were found. Due to differences in mechanical properties between ferrite and austenite, a heterogeneous stress distribution is generated in both phases. A method based on thermal-mechanical simulation was used to quantify ...
In the present paper, the chemical composition of passive films formed on both phases of two types of duplex stainless steels (UNS S31803 and UNS S32304) is determined at the micro-scale using Auger electron spectroscopy (AES). Samples were either mechanically polished (down to diamond pastes) or electrochemically etched in acidic solutions. The micro-electrochemical behavior of samples was then determined in sodium chloride media by means of the electrochemical micro-cell technique (capillary diameters of 30 ?m). The results obtained were analyzed considering the passive film chemical composition. Quantitative relationships between electrochemical parameters and the distribution of chromium and iron in the oxide layer were found. Due to differences in mechanical properties between ferrite and austenite, a heterogeneous stress distribution is generated in both phases. A method based on thermal-mechanical simulation was used to quantify surface ...
Clay-based materials can be cold-stabilized using binder and formed by extrusion. This paper deals with the properties of such materials under the influence of silico-aluminous flying ashes addition. Flying ashes are solid industrial wastes produced by coal combustion. Characteristics of ashes bearing clay-based products, such as dimensional stability, water and mechanical resistance, accelerated aging, are considerably improved with respect to simple clay-binder mixtures. This is principally due to a better hydration of the binder in ashes-bearing mixtures because of: a higher free-water availability as a consequence of the smaller specific surface of ash grains, the filler effect of ash grains which do not participate to the reactions, the specific property of silico-aluminous ashes that can fix the lime in presence of water to produce hydrated compounds. These ashes-bearing clay based materials can have the same qualities as classical building materials but their manufacturing ...
The author studied the conditions needed to routinely estimate the radiation dose in chicken bone by repeated re-irradiation and measuring ESR signals. Chicken meat containing bone was {gamma}-irradiated at doses of up to 3kGy, accepted as the commercially used dose. The results show that points in samplepreparation and ESR measurement are as follows: Both ends of bone are cut off and central part of compact bone is used for experiment. To obtain accurate ESR spectrum, marrow should be scraped out completely. Sample bone fragments of 1-2mm particle size and ca.100mg are recommended to obtain stable and maximum signal. In practice, by re-irradiating up to 5kGy and extrapolating data of the signal intensity to zero using linear regression analysis, radiation dose is estimated. For example, in one experiment, estimated doses of chicken bones initially irradiated at 3.0kGy, 1.0kGy, 0.50kGy and 0.25kGy were 3.4kGy, 1.3kGy, ...
Particle induced X-ray emission (PIXE) technique has been employed to perform elemental analysis of K, Ca, Mn, Fe, Cu, Zn, Br and Sr for Syrian medicinal plants used traditionally to enhance the body immunity. Plant samples were prepared in a simple dried base. The results were verified by comparing with those obtained from both IAEA-359 and IAEA-V10 reference materials. Relative standard deviations are mostly within {+-}5-10% suggest good precision. A correlation between the elemental content in each medicinal plant with its traditional remedial usage has been proposed. Both K and Ca are found to be the major elements in the samples. Fe, Mn and Zn have been detected in good levels in most of these plants clarifying their possible contribution to keep the body immune system in good condition. The contribution of the elements in these plants to the dietary recommended intakes (DRI) has been evaluated. Advantages and ...
This experiment was done to determine the effects of irradiation on the physical properties of three kinds of laminated packaging materials, i.e. polypropylene-polypropylene, polypropylene-polyethylene, polyester-polyethylene. Observations were made on pinhole production, leakage, oil resistance, resistance against insect penetration, colour, odour tensile strength, elongation at break, seal strength and tear resistance. The samples were irradiated with doses of 0, 5 and 10 kGy, then stored at room temperature and examined after 0, 3, 6 and 12 months of storage. The results showed that irradiation doses up to 10 kGy, as well as storage up to 12 months, did not create pinholes, or leakage in pouches prepared from laminated films. The resistance of the films to oil and insect penetration, the colour, and the odour were also unchanged. Both irradiation and storage treatments had a significant effect on physical properties of the laminated films. ...
The aim of this study was to search for a sorbent that could act as an extraction phase and as a support for solid-matrix time-resolved luminescence (SMTRL). Four potential sorbents were investigated for this purpose using tetracycline (TC) as a model analyte. Sorbents prepared from C18 silica gel or calcium cross-linked pectin gel were able to extract TC from dilute solutions. Europium(III)-TC complex adsorbed on the surface of C18 generated the most intense TRL signal when measured at {lambda}{sub ex} = 388 nm and {lambda}{sub em} = 615 nm. This method achieved a 1 ng/ml limit of detection (LOD) with a 100 {mu}l sample solution in a repeated spotting mode. Hyphenation of sorbent extraction and SMTRL was demonstrated using C18. This method is suitable for screening of TC in foods or aqueous solutions and can be extended to other luminescent lanthanide-chelating analytes in physiological or environmental samples.
Lithium carbonate pellets are frequently used for estimation of tritium production rate in irradiated samples in fusion blanket neutronics experiment and the activity is measured by liquid scintillation counting technique. In this measurement, it is essential to solve the lithium carbonate pellet as much as possible and to mix the pellet solution into scintillation cocktail homogeneously at stable condition. For this purpose, a novel binary-acid method has been developed to solve lithium carbonate and to mix the pellet solution into scintillation cocktail. High solubility is attained by adopting two acids, HNO_3 and CH_3COOH, and a good compatibility of the pellet solution with scintillator is obtained by emulsion cocktail resulting in high counting efficiency. Defining a product of dissolved mass and counting efficiency as a Figure of Merit (FOM), the present method has higher FOM value than the conventional method and is extremely simple in a ...
The kinetics of {sup 14}C-photosynthate import by developing wheat grains was followed after pulse-labeling the flag leaf with {sup 14}CO{sub 2}. Samples were collected from four successive points along the transport pathway to and within the grain: exuding aphid stylets on the peduncle, exuding grain pedicels, the grain crease tissues, and the liquid contents of the endosperm cavity. In addition, microautoradiographs were prepared of the grain crease tissues during movement of the {sup 14}C pulse into the grain. At all times, sucrose accounted for 93 to 97% of the total {sup 14}C present at all four sampling sites. The main features of the {sup 14}C kinetics could be accounted for by a simple compartmental model consisting of sucrose pools in series. Microautoradiographs of the crease tissues showed fairly uniform labeling of vascular parenchyma at all times, with a sharp gradient in labeling across the chalaza to the ...
This work reports an alternative methodology for the linear attenuation coefficient determination ({mu} {rho}) of irregular form samples, in such a way that is not necessary to consider the sample thickness. With this methodology, indigenous archaeological ceramics fragments from the region of Londrina, north of Parana, were studied. These ceramics fragments belong to the Kaingaing and Tupiguarani traditions. The equation for the {mu} {rho} determination employing the two mean method was obtained and it was used for {mu} {rho} determination by the gamma ray beam attenuation if immersed ceramics, by turns, in two different means with known linear attenuation coefficient. By the other side, {mu} theoretical value was determined with the XCOM computer code. This code uses as input the ceramics chemistry composition and provides an energy versus mass attenuation coefficient table. In order to validate the two mean method validation, five ceramics ...
Full text: Based on experience with nuclear material confiscated in Hungary from illicit trafficking activities in the nineties it has been decided that traditional gamma-spectrometry should be complemented by destructive analytical techniques. The 17/1996 (I. 31.) Korm. Governmental Decree delegated the identification, categorization and characterization tasks to the Institute of Isotopes, Budapest. Routine gamma-spectrometric methods have been further developed aiming at the i) age (production date) determination of seized samples and complete (nondismountable) uranium-bearing items (such as fresh fuel bundles and fission chambers) by HRGS technique, ii) improvement of measurement accuracy and reliability. Starting in 2005 mass spectrometry (ICP-SFMS) and scanning electron microscopy have been implemented to characterize nuclear samples in more detail and to analyze environmental samples both for isotopic and elemental ...
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 ...
Silicon on insulator (SOI) structures are promising candidates for the fabrication of VLSI circuits with very high packing densities. The preparation of such structures can now be achieved by high dose implantation of reactive ion species such as oxygen to produce buried layers of SiO/sub 2/ in silicon. In this paper we report experiments to depth profile these layered structures by SIMS. SOI samples have been prepared by implanting (100) silicon wafers with 400 keV molecular oxygen ions at a dose of 1.8x10/sup 18/ O/sup +/ cm/sup -2/. During the implantation the wafers were maintained at temperatures between 325 and 600/sup 0/C, using beam heating, which achieved in situ-annealing and ensured that the top silicon layer remained single crystal. Analysis was carried out on an Atomika DIDA-II spectrometer using 10 keV Ar/sup +/ ions with a low current density of less than 1 mA cm/sup -2/. During analysis negative secondary ...
Corrective Action Unit (CAU) No. 92, the Area 6 Decontamination Pond Facility (DPF), is an historic disposal unit located at the Nevada Test Site (NTS) in Nye County, Nevada (Figures 1 - 1, 1-2, and 1-3). The NTS is operated by the U.S. Department of Energy, Nevada Operations Office (DOE/NV), which has been required by the Nevada Division of Environmental Protection (NDEP) to characterize the DPF under the requirements of the Resource Conservation and Recovery Act (RCRA) Part A Permit (NDEP, 1995) for the NTS and Title 40 Code of Federal Regulations (CFR) Part 265 (1996c). The DPF is prioritized in the Federal Facility Agreement and Consent Order (FFACO, 1996) but is governed by the permit. The DPF was characterized through sampling events in 1994, 1996, and 1997. The results of these sampling events are contained in the Final Resource Conservation and Recovery Act Industrial Site Environmental Restoration Site Characterization Report, Area 6 ...
Wood Plastic Composites (WPCs) have experienced a healthy growth during the last decade. However, improvement in properties is necessary to increase their utility for structural applications. The toughness of WPCs can be improved by creating a fine cellular structure while reducing the density. Extrusion processing is one of the most economical methods for profile formation. For our study, rectangular profiles were extruded using a twin-screw extrusion system with different grades of HDPE and with varying wood fibre and lubricant contents together with maleated polyethylene (MAPE) coupling agent to investigate their effects on WPC processing and mechanical properties. Work has been done to redesign the extrusion system setup to achieve smoother and stronger profiles. A guiding shaper, submerged in the water, has been designed to guide the material directly through water immediately after exiting the die; instead of passing it through a water cooled vacuum calibrator and then through ...
Magnesium-based alloys are among the promising materials for hydrogen storage and fuel cell applications due to their high hydrogen content. In the present work, we investigated the hydrogen release/uptake properties of the Mg-Ti-H system. Samples were prepared from the mixtures of MgH{sub 2} and TiH{sub 2} in molar ratios of 7:1 and 4:1 using a high-energy-high-pressure (HEHP) mechanical ball-milling method under 13.8 MPa hydrogen pressure. Thermogravimetric analysis (TGA) showed that a relatively large amount of hydrogen (5.91 and 4.82 wt.%, respectively, for the above two samples) was released between 126 and 313 C while temperature was increased at a heating rate of 5 C min{sup -1} under an argon flow. The onset dehydrogenation temperature of these mixtures, which is 126 C, is much lower than that of MgH{sub 2} alone, which is 381 C. The activation energy of dehydrogenation was 71 kJ mol{sup -1}, which is much smaller ...
Burnaid is a sorbalene-based cream containing 40 mg/g of tea tree oil and 1 mg/g of triclosan. This investigation was carried out to determine the effect of Burnaid, a commercial tea tree oil preparation, against Enterococcus faecalis (ATCC29212), Staphylococcus aureus (ATCC29213), Escherichia coli (ATCC25922), and Pseudomonas aeruginosa (ATCC27853), with the activity of the base product in the commercial preparation. The organisms were suspended in sterile saline (0.5 McFarland Standard) and inoculated onto horse blood agar (E. faecalis and S. aureus) or Mueller-Hinton agar (E. coli and P. aeruginosa). One hundred microliters of Burnaid unsterilized, Burnaid sterilized and the base product (Tinasolve) were placed in duplicate in wells cut into the agar plates. Sterility and inactivation cultures were also performed on the samples. None of the samples were found to be contaminated with bacteria prior to ...
The commercial solid phase microextraction (SPME) fibers are not stable enough in organic solvent and tend to swell and strip off from the silica fiber in the high performance liquid chromatography (HPLC) mobile phase, and therefore the application of SPME coupled online with HPLC is limited. In this study, an SPME fiber coated with single walled carbon nanotubes (SWCNTs), prepared by means of electrophoretic deposition, was coupled on line to HPLC for the determination of four endocrine-disrupting compounds, i.e. bisphenol A (BPA), estrone (E(1)), 17?-ethynylestradiol (EE(2)) and octylphenol (OP), in aqueous samples. The results showed that the SWCNTs coating on the prepared fiber did not swell and strip off from the platinum fiber throughout the experiment, thus indicating a high resistance to the HPLC mobile phase, the mixture of water and acetonitrile. The SWCNTs fiber had similar (for OP) or higher (for BPA, EE(2) and ...
This study aimed to correlate the efficiency of enzymatic hydrolysis of the cellulose contained in a sugarcane bagasse sample pretreated with dilute H(2)SO(4) with the levels of independent variables such as initial content of solids and loadings of enzymes and surfactant (Tween 20), for two cellulolytic commercial preparations. The preparations, designated cellulase I and cellulase II, were characterized regarding the activities of total cellulases, endoglucanase, cellobiohydrolase, cellobiase, ?-glucosidase, xylanase, and phenoloxidases (laccase, manganese and lignin peroxidases), as well as protein contents. Both extracts showed complete cellulolytic complexes and considerable activities of xylanases, without activities of phenoloxidases. For the enzymatic hydrolyses, two 2(3) central composite full factorial designs were employed to evaluate the effects caused by the initial content of solids (1.19-4.81%, w/w) and ...
A solid-state precipitation process was used to prepare superconducting tapes containing an A15 phase, V/sub 3/Ga or Nb/sub 3/Al, in a ductile niobium or vanadium containing BCC matrix. Ingots weighing as large as 30 to 50 gms of V-(14 approx. 19 at. %) Ga and Nb-(13 approx. 22 at. %) Al were prepared by arc-melting, homogenized, quenched, warm-rolled over 99% into tape, and aged at temperatures in the range 600/sup 0/C to 1000/sup 0/C to precipitate the superconducting A15 phase. The features demonstrated by the process are very attractive for practical applications. In the V-Ga system, transmission electron microscopy (TEM) studies revealed the A15 precipitates in an elongated form. However, for the Nb-Al samples, deformed and aged at 750/sup 0/C, TEM studies revealed A15 precipitation in fine equi-axed particles which formed as a semi-continuous network over sub-grain boundaries formed by the recovery of ...
Purpose - The purpose of this paper is to explore the functionality of multistage programming approach on network supply chain structure. Design/methodology/approach - The general supply chain structure is considered and the supply chain planning model is developed using a two stage programming approach. The same model is extended to cover the applicability and advantages of a multi-stage programming approach. Findings - A multi-period supply chain model for new product launches under uncertain demand for supply chain network structure has been developed. The model allows simultaneous determination of optimum procurement quantity, production quantity across the different plants, transportation routes and the outsourcing cost in case of shortages. The proposed multi-stage model is compared ...
BackgroundSince implementation of the Model for End-stage Liver Disease (MELD), the number of simultaneous liver-kidney transplantations (SLKT) has increased in the United States. However, predictors and survival benefit of SLKT compared to liver transplantation alone (LTA) are not well defined. MethodsOrgan Procurement and Transplantation Network data of patients with end-stage liver disease (ESLD) with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 who had not been on dialysis while on the waiting list and underwent liver transplantation between 2002 and 2008 were analyzed. To identify predictors of undergoing SLKT versus LTA, multiple logistic regression analysis was performed. Cox proportional hazards regression analysis was used to assess the association between...
A newly-available radioisotopic system, /sup 172/Hf-/sup 172/Lu, has excellent potential for tracer applications in which nuclear data acquisition must be accomplished in real time. The 6.7-day half-life of /sup 172/Lu is sufficient for a large fraction of tracer experiments, and should allow the direct incorporation of /sup 172/Lu into tests that have traditionally utilized much longer-lived radionuclides. Since /sup 172/Lu is the daughter component of a radioisotope generator, however, its effective shelf-life is determined by the half-life of its 1.9-year /sup 172/Hf parent. Consequently, the frequency of isotope procurement need not be any more extensive than investigators would normally be accustomed to. Discussion relevant to isotope production, generator operation, and nuclide acquisition is presented in this paper.
Anti-jamming techniques to improve Global Positioning System (GPS) receivers robustness have been mainly developed in military applications. None of civilian techniques can procure sufficient robustness against occasional or intentional jammers for civil GPS or GALILEO navigation receivers. The amplitude domain processing (ADP) filtering is a technique based upon Capon works and Neyman-Pearson theory. Several experiments concerning the ADP filtering have been considered at the 3DETSNAV division of LACIME laboratory at Ecole de technologie superieure (ETS), which have proved that the technique is reliable in order to eradicate powerful interference present in the spread spectrum signal. However, the results show that the ADP filter has a real limitation when submitted to multiple interferen...
The Hazardous Materials Control Module (HMC) is one module of four for the Industrial Health component. The HMC module was designed to inform employees of health and safety hazards in the workplace and to track the movement of hazardous materials through the facility. The module performs these functions by maintaining health and safety data on hazardous materials used in the facility, and by tracking who requests information about any hazardous materials. The HMC module gets its information from two sources. The first one is the Hazardous Materials Information System (HMIS), this is a national system that is used by the Department of Defense. It is loaded on to the system via tapes that contain all safety, health and transportation information about a particular product. The second is Material Safety Data Sheets (MSDS) that are procured by a particular site. This information is manually entered into their own personal system, which they give a site specific ...
Studies continued on organic tracers for use as hydrologic tracers as part of the Yucca Mountain Site Characterization project. This subject report for the quarter 01/01/93 through 03/31/93 discusses the following issues: project organization and responsibilities; quality assurance program; design control; procurement document control; instructions, procedures, and drawings; document control; control of purchased items and services; identification and control of items; control of processes; inspection; test control; control of measuring and test equipment; handling, storage, and shipping; inspection, test, and operating status; control of nonconforming items and conditions; corrective action; quality assurance records; audits; software quality assurance; and scientific investigation.
The presence of inefficient distribution networks and supply chains of medicines creates problems in that even if African countries can secure steep, sustainable cost-containing procurements, access to needed medicines may still be impaired. The expected health benefits from affordable pricing or subsidies on prices of medicines may not be realized. This article evaluates drug supply chains in African countries and advocates for consolidated private wholesale markets and multiplicity of retail pharmacies. Public supply chains should be shortened and supported by contracting out with private distributors, including wholesalers and retail pharmacies. Additionally, drug regulatory authorities should be allowed to charge registration fees that are proportionate to the costs of technical regula...
Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with ...
Samarium cobaltite ceramic perovskites, with and without platinum particles dispersion, are possible candidates as electrode for electrochemical conversion of hydrocarbon and for intermediate temperature solid oxide fuel cells (ITSOFC). In this work, samarium cobaltites were synthesized by the combustion method using cobalt, and samarium nitrates as cation precursors and urea as fuel. For containing-platinum compositions Pt (II) acetyl acetonate was also employed as precursor. The effect of Sr on the phase formation and its electrical behavior is also studied. Specific surface area (BET), SEM-EDX, TEM and XRD analysis are used to characterize the powders obtained. Powders were pressed into pellets and sintered in air in the temperature range of 1200 -1400 C. Electrical impedance spectroscopy studies (EIS) are performed on sintered samples. The as-prepared powders showed an amorphous structure and by TEM a very small particle size ...
Aqueous solutions (mixed waste) generated from various LLNL operations, such as debris washing, samplepreparation and analysis, and equipment maintenance and cleanout, were combined for storage in the B695 tank farm. Prior to combination the individual waste streams had different codes depending on the particular generating process and waste characteristics. The largest streams were CWC 132, 791, 134, 792. Several smaller waste streams were also included. This combined waste stream was treated at LLNL's waste treatment facility using a vacuum filtration and cool vapor evaporation process in preparation for discharge to sanitary sewer. Prior to discharge, the treated waste stream was sampled and the results were reviewed by LLNL's water monitoring specialists. The treated solution was discharged following confirmation that it met the discharge criteria. A major source, accounting for ...
The purpose of the present study was to prepare a novel domperidone hydrogel. The domperidone dispersion was prepared by the solvent evaporation method. The characteristics of domperidone dispersion...Full Text Available
Mixed-conducting ceramic oxides have potential uses in high-temperature electrochemical applications such as solid oxide fuel cells, advanced batteries, sensors, and oxygen-permeable membranes. The Sr-Fe-Co-O system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. Dense ceramic membranes made of this material can be used to separate high-purity oxygen from air without the need for external electrical circuitry, or to partially oxidize methane to produce syngas. Samples of Sr{sub 2}Fe{sub 3{minus}x}Co{sub x}O{sub y} (with x = 0, 0.6, 1.0, and 1.4) were prepared by solid-state reaction in atmospheres with various oxygen partial pressures (pO{sub 2}) and were characterized by X-ray diffraction, scanning electron microscopy, and electrical conductivity measurements. Phase components of the samples are dependent on cobalt concentration and synthesis pO{sub 2}. Total ...
This paper presents a group's efforts to introduce national newborn screening in Lebanon. Tandem mass spectrometry (MS) technology offers the prospect of utilizing filter paper blood specimens to screen newborns for several metabolic disorders. In order to be cost-effective, it is necessary to have a mandatory newborn screening policy. At present such a policy is not available in Lebanon. A national screening survey for congenital hypothyroidism (CH) was carried out to assess the incidence of this anomaly in the Lebanese population. Such an initiative is essential as a first step for assessing the feasibility and cost of a national screening programme. Coated beads, blood spot standards for quality control and buffer solutions used for assays were prepared in-house to minimize costs. At first, samples of umbilical cord blood spots were assayed for TSH using IRMA technique. Those samples showing borderline or high values of ...
Iron doped semiconducting nanoparticles Sn1-xFexO2 with x=0, 0.001, 0.002, 0.003, 0.004, 0.01 and 0.03 were prepared by a sol-gel method. The X-ray diffraction, Transmission Electron Microscopy measurements confirm the rutile structure with no impurity phase. The three characteristic lines of electron spin resonance (ESR) are observed in the doped samples for all compositions, which is a clear evidence for rhombic Fe3+ in rutile phase. The line width of ESR increases with increase in Fe concentration due to induced disorder. The spin-pumping effect is observed at temperatures below 250 K for the samples with x=0.01 and 0.03. However, based on the Curie-Weiss susceptibility, iron is in paramagnetic state and is subject to weak antiferromagnetic interaction. Blue shift in the optical band gap is observed with increase in the Fe content. -- Graphical abstract: The ESR spectra reveal that the nature of Fe in Sn1-xFexO2 ...
Samples from three mine tailings, the Hemlo Mine (located in Northern Ontario), the Louvicourt Mine, and the Laronde Mine (both located in Northwestern Quebec) and four different types of hydraulic binder in three different proportions (3, 4.5, 6 per cent of total dry weight of tailings) were used to prepare 33 recipes for cement caulk. The sulphur content of the three tailings is, respectively, 5 per cent, 16 per cent, and 32 per cent. Three of the four hydraulic binders are in fact a mix of two cement types: binder based on Portland cement (CP), binder based on fly ash (FA), and binder based on dross (CL). The fourth binder is based mainly on dross. The coupons of caulk dykes were flushed at 14, 28, 56, and 91 days in a humid chamber. At each of these steps, the samples were characterized for chemical, geochemical, physical, microstructural, and mechanical attributes to better understand the hydrogeochemical properties of ...
The lipid fractions of residues from historical pharmaceutical ointments were analysed by reversed-phase liquid chromatography coupled with atmospheric pressure chemical ionization and mass spectrometer detection. The residues were contained in a series of historical apothecary jars, dating from the eighteenth century and conserved at the "Aboca Museum" in Sansepolcro (Arezzo, Italy) and at the pharmacy of the "Real Cartuja de Valldemossa" in Palma de Majorca (Spain). The analytical protocol was set up using a comparative study based on the evaluation of triacylglycerol (TAG) compositions in raw natural lipid materials and in laboratory-reproduced ointments. These ointments were prepared following pharmaceutical recipes reported in historical treatises and used as reference materials. The reference materials were also subjected to stress treatments in order to evaluate the modification occurring in the TAG profiles as an effect of ageing. TAGs were successfully ...
An evaluation of eastern shale oil (ESO) residue as an asphalt additive to reduce oxidative age hardening and moisture susceptibility was conducted by Western Research Institute (WRI). The ESO residue, have a viscosity of 23.9 Pa{lg_bullet}s at 60{degree}C (140{degree}F), was blended with three different petroleum-derived asphalts, ASD-1, AAK-1, and AAM-1, which are known to be very susceptible to oxidative aging. Rheological and infrared analyses of the unaged and aged asphalts and the blends were then conducted to evaluate oxidative age hardening. In addition, the petroleum-derived asphalts and the blends were coated onto three different aggregates, Lithonia granite (RA), a low-absorption limestone (RD), and a siliceous Gulf Coast gravel (RL), and compacted into briquettes. Successive freeze-thaw cycling was then conducted to evaluate the moisture susceptibility of the prepared briquettes. The rheological analyses of the unaged petroleum-derived asphalts and ...
The use of environmental monitoring as a technique to identify activities related to the nuclear fuel cycle has been proposed by international safeguards organizations. The elements specific for each kind of nuclear activity, or 'nuclear signatures', inserted in the ecosystem can be intercepted by different live organisms. This work demonstrates the technical viability of using pine needles as bioindicators of nuclear signatures associated with uranium enrichment activities. Additionally, it proposes the use of HR-ICP-MS to identify the signature corresponding to that kind of activities in the ecosystem. Nitric acid solutions, used to wash pine needles sampled near nuclear facilities and containing only 0.1 #mu#g x kg"-"1 of uranium, exhibit a n("2"3"5U)/n("2"3"8U) isotopic abundance ratio of 0.0092#+-#0.0002, while solutions originated from samples collected at places located more than 200 km far from activities related to the nuclear fuel ...
The quantitative determination of oxide concentration by laser-induced breakdown spectroscopy is relevant in various fields of applications (e.g.: analysis of ores, concrete, slag). Calibration free laser-induced breakdown spectroscopy and the multivariate calibration are among the methods employed for quantitative concentration analysis of complex materials. We measured the intensity of neutral and ionized atomic emission lines of oxide materials by laser-induced breakdown spectroscopy and we modified the calibration free laser-induced breakdown spectroscopy method to increase the accuracy. The concentration of oxides was obtained by using stoichiometric relations. Sample materials were prepared from oxide powder (Fe{sub 2}O{sub 3}, MgO, CaO) by mixing and pressing. The concentration was 9.8-33.3 wt.% Fe{sub 2}O{sub 3}, 7.6-33.3 wt.% MgO and 33.3-81.2 wt.% CaO for different samples. Nd:YAG laser (wavelength 1064 nm, pulse ...
The Richland Operations Office (RL) and Office of River Protection (ORP) are pleased to issue the attached Pollution Prevention Progress Report. We have just met the most aggressive waste reduction and A recycling goals to date and are publishing this report to recognize A the site's progress, and to ensure it will sustain success beyond 1 Fiscal Year 2000. This report was designed to inform the been made by RL and ORP in Waste Minimization (WMin) and Pollution Prevention (P2). RL, ORP and their contractors are committed to protecting the environment, and we reiterate pollution prevention should continue to be at the forefront of the environmental cleanup and research efforts. As you read the attached report, we believe you will see a clear demonstration of RL and ORP's outstanding performance as it has been responsible and accountable to the nation, its employees, and the community in which we live and work. commitment that all employees have for environmental ...
The synthesis, crystal structure, thermal stability and absorbance spectra of perovskite-type oxynitrides with the general formula SrTi1-xNbx(O,N)3 (x=0.05, 0.10, 0.20, 0.50, 0.80, 0.90, 0.95) have been investigated. Oxide samples were prepared by a polymerized complex synthesis route and post-treated under ammonia at 850 oC for 24 h to substitute nitrogen for oxygen. Synchrotron X-ray powder diffraction (XRD) evidenced that the mixed oxide phases were all transformed into oxynitrides with perovskite-type structure during a thermal ammonolysis. SrTi1-xNbx(O,N)3 with compositions x?0.80 crystallized in a cubic and samples with x?0.90 in a tetragonal structure. The Rietveld refinement indicated a continuous enlargement of the lattice parameters towards higher niobium content of the samples. Thermogravimetric analysis (TGA) and hotgas extraction revealed the dependence of the nitrogen incorporation upon ...
This Corrective Action Decision Document/Closure Report (CADD/CR) has been prepared for Corrective Action Unit (CAU) 409: Other Waste Sites, Tonopah Test Range (TTR), Nevada, in accordance with the Federal Facility Agreement and Consent Order. Located near Area 3 on the TTR approximately 140 miles northwest of Las Vegas, Nevada, CAU 409 is comprised of three Corrective Action Sites (CASs): CAS RG-24-001-RGCR, Battery Dump Site; CAS TA-53-001-TAB2, Septic Sludge Disposal Pit (referred to as Septic Sludge Disposal Pit No.1); CAS TA-53-002-TAB2, Septic Sludge Disposal Pit (referred to as Septic Sludge Disposal Pit No.2). This CADD/CR identifies and rationalizes the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Operations Office's (NNSA/NV's) recommendation that no corrective action is deemed necessary for CAU 409. The CADD/CR have been combined into one report based on sample data collected ...
An x-ray zone plate was fabricated using the novel approach of focused ion beam (FIB) milling. The FIB technique was developed in recent years, it has been successfully used for transmission electron microscopy (TEM) samplepreparation, lithographic mask repair, and failure analysis of semiconductor devices. During FIB milling, material is removed by the physical sputtering action of ion bombardment. The sputter yield is high enough to remove a substantial amount of material, therefore FIB can perform a direct patterning with submicron accuracy. The authors succeeded in fabricating an x-ray phase zone plate using the Micrion 9500HT FIB station, which has a 50 kV Ga{sup +} column. Circular Fresnel zones were milled in a 1.0-{micro}m-thick TaSiN film deposited on a silicon wafer. The outermost zone width of the zone plate is 170 nm at a radius of 60 {micro}m. An achieved aspect ratio was 6:1.
Polycrystalline soft ferrite, Cu1+xSixFe2?2xO4 (x=0.0, 0.05, 0.1, 0.15, 0.2 and 0.3) were prepared by standard ceramic technique. The X-ray analysis confirmed the single phase formation of the samples up to x=0.1 beside a second phase for x?0.15. The lattice parameter was found to decrease with composition(x), which is attributed to ionic size difference of cations involved. The bulk density measurements shows two different behavior for x0.15. The IR spectra of Cu Si ferrite system have been analyzed in the frequency range 200 1200 cm?1. It revealed two prominent bands ?1 and ?2 which are assigned to tetrahedral and octahedral metal complexes, respectively. The position of the highest frequency band is around 575 cm?1 while the lower frequency band is around 400 cm?1.
The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the ...
Polycrystalline ZnS semiconducting films have been prepared in sandwich configuration by spray pyrolysis technique using ZnO-coated glass substrates and mixed aqueous solutions of ZnCl{sub 2} and thiourea. The sandwich structures have been produced successfully by means of ZnO-coated glass substrates. The produced ZnS films have been crystallized in a wurtzite structure and had a direct band gap energy of 3.62 eV. The electrical properties of the sample have been studied by an analysis based on the thermally stimulated current spectra in the temperature range of 40-300 K with various heating rates. A set of curves of I (T) for varying initial density of filled traps at a heating rate of {beta} {sub 2}=0.06 K s{sup -1} indicate that the observed peaks in the TSC curve of polycrystalline ZnS films have first-order features. In order to evaluate the trap parameters of ZnS films, we have used curve-fitting method. The values of the frequency factor ...
We have investigated the superconducting and metallurgical properties of the ternary compounds RPd/sub 2/Si/sub 2/ and RRh/sub 2/Si/sub 2/ with R = Y, La, and Lu. All RPd/sub 2/Si/sub 2/ compounds and LaRh/sub 2/Si/sub 2/ were found to be type-I superconductors below 1 K. A detailed metallurgical analysis shows that segregation of second phases can easily mask the intrinsic (stoichiometric ratio 1:2:2) intermetallic-compound properties. Two sample-preparation techniques, viz., single crystals and off-stoichiometry, were utilized to establish where bulk superconductivity occurs. The type-I behavior of these compounds is explained with an analogous model as is used for the heavy-fermion superconductors CeCu/sub 2/Si/sub 2/ and URu/sub 2/Si/sub 2/.
Superconductivity of binary alloys spanning the A-15 compounds V/sub 3/Si, V/sub 3/Ge, V/sub 3/Ga, and V/sub 3/Al and the pseudobinary derivatives of these stoichiometric compounds was surveyed by studying samplesprepared by rf-sputtering from alloy cathodes. The possible formation of the hypothetical A-15 binaries ''V/sub 3/P,'' ''V/sub 3/B,'' and ''V/sub 3/C'' and their pseudobinary formation with V/sub 3/Si was also explored. Efforts to form these hypothetical alloys were not successful. The T/sub c/'s were measured resistively and the structure and lattice constants were determined by x-ray analysis. A maximum T/sub c/ of 11.7/sup 0/K was obtained for A-15 V/sub 3/Al, and the importance of a suitable deposition temperature and high sputtering pressures was examined. It is proposed that large variations of T/sub c/ among ...
Superconductivity of binary alloys spanning the A-15 compounds V_3Si, V_3Ge, V_3Ga, and V_3Al and the pseudobinary derivatives of these stoichiometric compounds was surveyed by studying samplesprepared by rf-sputtering from alloy cathodes. The possible formation of the hypothetical A-15 binaries ''V_3P,'' ''V_3B,'' and ''V_3C'' and their pseudobinary formation with V_3Si was also explored. Efforts to form these hypothetical alloys were not successful. The T/sub c/'s were measured resistively and the structure and lattice constants were determined by x-ray analysis. A maximum T/sub c/ of 11.7"0K was obtained for A-15 V_3Al, and the importance of a suitable deposition temperature and high sputtering pressures was examined. It is proposed that large variations of T/sub c/ among pseudobinary alloys imply a rapid variation of the density of states at the Fermi level.
The layered cobaltate La0.30CoO2 was prepared from NaxCoO2 precursor by a solid-state ionic exchange and was characterized by means of X-ray and neutron diffraction, magnetic, thermal and electric transport measurements. The compound consists of hexagonal sheets of edge-sharing CoO6 octahedra interleaved by lanthanum monolayers. Compared to Na+ in the parent system, the La3+ ions occupy only one-third of available sites, forming a 2-dimensional superstructure. The deviation from the ideal stoichiometry La1/3CoO2 introduces extra hole carriers into the diamagnetic LS Co3+ matrix making the sample Pauli paramagnetic. The temperature dependence of the electrical conductivity in La0.30CoO2 follows Mott's T?1/3 law up to about 400K, which is in contrast w...
New rare earth metal rich cadmium compounds RE_4CoCd and RE_4RhCd (RE = Tb, Dy, Ho) were prepared by high-frequency melting of the elements in sealed tantalum tubes. The samples were studied by x-ray powder and single-crystal diffraction. All the compounds crystallize with Gd_4RhIn-type structure, with space group F4-bar3m. The structures are built up from rigid three-dimensional networks of condensed, cobalt (rhodium) centred trigonal RE_6 prisms. The voids left by these networks are filled by Cd_4 cluster units and the coordination number 14 polyhedra of the RE1 atoms. The terbium and dysprosium compounds in both series undergo antiferromagnetic ordering, whereas the holmium compounds exhibit ferromagnetic ordering. The magnetic ordering in these compounds is characterized by broad peaks around the transition temperatures. The results of detailed crystallographic investigations and preliminary magnetic and specific heat studies are presented ...
Standard Leadframes used in surface mount technology are finished with a layer of eutectic SnPb for passivation and for enhancing solder wetting during reflow. When eutectic SnPb is replaced by Pb-free solder, especially the eutectic SnCu, a large number of Sn whiskers are found on the Pb-free finish. Some of the whiskers are long enough to become shorts between the neighboring legs of the leadframe. How to suppress their growth and how to perform accelerated test of Sn whisker growth are crucial reliability issues in the electronic packaging industry. In this paper, we report the study of spontaneous Sn whisker growth at room temperature on eutectic SnCu and pure Sn finishes. Both compressive stress and surface oxide on Sn are necessary conditions for whisker growth. Structure and stress analyses by using the micro-diffraction in synchrotron radiation are reported. Cross-sectional electron microscopy, with samplesprepared by focused ion beam, ...
The use of n-alkanethiolate self-assembled monolayers on gold has blossomed in the past few years. These systems have functioned as models for common interfaces. Thiolate monolayers are ideal because they are easily modified before or after deposition. The works contained within this dissertation include interfacial characterization (inbred reflection absorption spectroscopy, ellipsometry, contact angle, scanning probe microscopy, and heterogeneous electron-transfer kinetics) and various modeling scenarios. The results of these characterizations present ground-breaking insights into the structure, function, and reproducible preparation of these monolayers. Surprisingly, three interfacial properties (electron-transfer, contact angle, and ellipsometry) were discovered to depend directly on the odd-even character of the monolayer components. Molecular modeling was utilized to investigate adlayer orientation, and suggests that these effects are adlayer structure ...
Praseodymium-doped Bi{sub 4}Ti{sub 3}O{sub 12} (BIT) with various compositions of dopant, Pr (x = 0.5, 0.6, 0.7, 0.8) in Bi{sub 4-x}Pr{sub x}Ti{sub 3}O{sub 12} (BPT) were synthesized using a low temperature wet chemical technique. Powders calcined at 800 deg. C exhibit a single phase polycrystalline perovskite bismuth-layered structure. Randomly oriented plate-like structures were observed under Scanning Electron Microscope (SEM). A small amount of Pr doping (x = 0.5) resulted in dramatically reduced of grain size from 2 {mu}m to less than 50 nm in which Pr plays the role as a grain growth inhibitor. However, by increasing the composition of Pr, bigger grain size of up to 1 {mu}m was observed for x = 0.8 that was caused by diffusion of Pr in the perovskite structure. Dielectric properties showed that dielectric permittivity decreased with the addition of x = 0.50, and increasing with further addition of Pr. Dissipation factor (tan {delta}) followed the same trend as dielectric constant ...
Praseodymium-doped Bi_4Ti_3O_1_2 (BIT) with various compositions of dopant, Pr (x = 0.5, 0.6, 0.7, 0.8) in Bi_4_-_xPr_xTi_3O_1_2 (BPT) were synthesized using a low temperature wet chemical technique. Powders calcined at 800 deg. C exhibit a single phase polycrystalline perovskite bismuth-layered structure. Randomly oriented plate-like structures were observed under Scanning Electron Microscope (SEM). A small amount of Pr doping (x = 0.5) resulted in dramatically reduced of grain size from 2 #mu#m to less than 50 nm in which Pr plays the role as a grain growth inhibitor. However, by increasing the composition of Pr, bigger grain size of up to 1 #mu#m was observed for x = 0.8 that was caused by diffusion of Pr in the perovskite structure. Dielectric properties showed that dielectric permittivity decreased with the addition of x = 0.50, and increasing with further addition of Pr. Dissipation factor (tan #delta#) followed the same trend as dielectric constant that was attributed to the ...
This report presents the status of development of a three-dimensional conceptual model for the unconfined aquifer system at Hanford. A conceptual model is needed to support development of a realistic three-dimensional numerical model for predicting ground-water flow and the transport of contaminants. The report focuses on developing a hydrogeologic framework, assessing available hydraulic property data, describing flow-system boundaries, and evaluating areal recharge and leakage. Geologic descriptions of samples obtained during well drilling were used to prepare cross sections that correlate relatively continuous layers. The layers were defined based on textural differences that are expected to reflect differences in hydraulic properties. Assigning hydraulic properties to the layers is a critical part of the conceptual model. Available hydraulic property data for the study area were compiled and were correlated with the geologic layers where ...
Based on an multivariate statistical evaluation of binary and metric data relating to the soil cover of the European Community five regionally representative reference soils (EURO-Soils) have been identified for chemicals testing in the EC. The soil material sampled at representative localities in Italy, Greece, Great Britain, France and Germany was treated and prepared according to OECD Test Guideline 106 and analysed in detail. The homogenised specimens were subject to an EC-wide ring test to evaluate the feasibility of the modified guideline and to validate the physical-chemical amenability of the reference soils for sorption tests. The results proved the validity of the soils selected for assessing the potential behaviour of new chemicals in soil on the basis of a comparative evaluation of the individual test results obtained. In the light of this parametric assessment potential test soils were subsequently identified in the individual EC ...
The document describes the outcome of the CSN/CIEMAT-00 interlaboratory test comparison among environmental radioactivity laboratories. the exercise was organised according to the ISO-43 and the ISO/IUPAC/AOAC Harmonized Protocol for the proficiency testing of analytical laboratories. the test sample was a soil containing environmental levels of K-40, Ra-226, Ac-228, Sr-90, Cs-137, Cs-134, Pu (239-240) y Am-241. the Universidad Autonoma de Barcelona prepared the material and reported adequate statistical studies of homogeneity. The results of the exercise were computed for 30 participating laboratories, and their analytical performance was assessed using the u-score approach. A raised percentage of satisfactory laboratory performance has been obtained for all the analysis, being the best performance in gamma measurements. The exercise has drawn that several laboratories have difficulties in the evaluation of combined uncertainty, mainly in ...
Plutonium metal is produced by reducing PuF{sub 4} prepared from PuO{sub 2} by fluorination. Both fluorination and reduction are batch processes at the Los Alamos Plutonium Facility. The conversion of plutonium oxide to fluoride greatly increases the neutron yield, a result of the high cross section for alpha-neutron ({alpha},n) reactions on fluorine targets compared to the (more than 100 times) smaller {alpha},n yield on oxygen targets. Because of the increase, total neutron counting can be used to monitor the conversion process. This monitoring ability can lead to an improved metal product, reduced scrap for recycle, waste reduction, minimized reagent usage, and reduce personnel radiation exposures. A new stirred-bed fluorination process has been developed simultaneously with a recent evaluation of an automated neutron-counting instrument for quantitative process monitoring. Neutrons are counted with polyethylene-moderated {sup 3}He-gas proportional counters. ...
Recently we have found a highly effective additive for the melt growth processings attaining high critical currents in YBCO superconductor. It is platinum and it behaves as an effective grain growth inhibitor for the Y{sub 2}BaCuO{sub 5} phase. Even with less than 1 wt.% doping, Y{sub 2}BaCuO{sub 5} particles becomes less than one micron in size and distribute themselves to become homogeneously embedded in the large grown YBa{sub 2}Cu{sub 3}O{sub y} grains. The sample shows large magnetic hysteresis and a typical J{sub c} value estimated by using Bean's model critical state model is 18000 A/cm{sup 2} at 77 K and 1 T. We found that rhodium has a similar remarkable effect. (orig.).
ZrO_2/O'-sialon composites were obtained via reaction sintering of ZrSiO_4 and Si_3N_4 powders at about 1700 deg C. Y_2O_3 was effective in both stabilizing of zirconia and densifying the composites. However, it is not easy to select an optimum value of the single additive to balance these two requirements simultaneously. With low Y_2O_3 addition, some tetragonal zirconia grains in the sintered samples are transformable during mechanical grinding but the full densification of the material is then sacrificed. On the other hand, addition more Y_2O_3 to achieve complete densification results in the zirconia being stabilized into undesirable t' or cubic forms. Therefore no improved toughening effects have been achieved in the composites. Heat-treatment of the materials at 1400 deg C. results in the diffusion of yttria from the grain boundary phase to zirconia and the formation of the O'-cubic zirconia composite may still provide a useful refractory material. 11 refs., ...
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 the Cretaceous ...
Prepared to make housing project managers, maintenance engineering staff, and designers and architects of HUD - assisted and HUD - insured housing projects and mobile home parks aware of their responsibilities under the Natural Gas Pipeline Safety Act, this handbook provides technical guidance for the reduction of gas leaks and the handling of gas leak incidents in residential areas. The hazards of natural gas, concern over gas safety in residential areas, applicable codes and standards, and sources of information and help are reviewed, along with maintenance and engineering considerations relating to gas pipe failures, the detection of gas leaks, appliance servicing, and pipe installation, repair, and replacement. Housing management considerations are also examined, with attention to recordkeeping and reporting, emergency contingency planning, tenant education, staff qualifications and training, and the development and use of a maintenance and operations manual. ...
Nanodimensional powders of cubic copper ferrite are synthesized by two-steps procedure of co-precipitation of copper and iron hydroxide carbonates, followed by mechanochemical treatment. X-ray powder diffraction, Moessbauer spectroscopy and temperature-programmed reduction are used for the characterization of the obtained materials. Their catalytic behavior is tested in methanol decomposition to hydrogen and CO and total oxidation of toluene. Formation of nanosized ferrite material is registered even after one hour of milling time. It is established that the prolonging of treatment procedure decreases the dispersion of the obtained product with the appearance of Fe2O3. It is demonstrated that the catalytic behavior of the samples depends not only on their initial phase composition, but on the concomitant ferrite phase transformations by the influence of the reaction medium. -- Graphical abstract: It is demonstrated that the catalytic behavior of the obtained copper ...
Piezoelectric ceramics for acoustic applications have been prepared by mixing the piezoelectric phase Pb{sub 1-1.5x}La{sub x}{open_square}{sub x/2}(Ti{sub 1-y}Zr{sub y})O{sub 3} (PLZT) with variable fractions of Al{sub 2}O{sub 3}. The samples are in form of pellets and polarized at high temperature. After thermal treatment, X-ray diffraction and scanning electron microscopy have been used to determine the phase and morphological modifications. The morphotropic PLZT initial phase disproportionates into modified PLZT and ZrO{sub 2} phases. Using electrical impedance spectroscopy, the resonance frequencies of the composite system have been determined and analyzed. As the Al{sub 2}O{sub 3} volume fractions increase, the resonance frequency and the amplitude of the electrical response both decrease. An interpretation of the role of Al{sub 2}O{sub 3} additions is proposed in terms of phase and microstructure modifications. Using LRC electrical ...
Powders with nominal compositions (in atomic percent) Ti-48Al and Ti-48Al-2Nb-2Cr were prepared by the plasma rotating electrode process (PREP) and gas atomization (GA) techniques. As-solidified and heat-treated (1000degC per 3 h) powder samples were examined by metallography, scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The microstructures of the powders were characterized as a function of atomization technique, alloy content, powder particle size (solidification rate) and thermal history. All of the as-solidified powders were comprised of disordered [alpha], and ordered [alpha][sub 2]-Ti[sub 3]Al and [gamma]-TiAl. For both alloys, a larger volume fraction of [alpha] and [alpha][sub 2] was observed in the PREP powders relative to GA powders of comparable size. Additionally, for both alloys and both atomization techniques, the volume fraction of [alpha][sub 2] was observed to increase with decreasing ...
We have carried out studies on the rheological properties of regenerated silk fibroin (RSF) solution using video microscopy. The degummed silk from the Bombyx mori silkworm was used to prepare RSF solution by dissolving it in calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by tracking the position of an embedded micron-sized polystyrene bead within the RSF solution through video imaging. The time dependent mean squared displacement (MSD) of the bead in solution and hence, the complex shear modulus of this solution was calculated from the bead's position information. An optical tweezer was used to transport and locate the bead at any desired site within the micro-volume of the sample, to facilitate the subsequent free-bead video analysis. We present here the results of rheological measurements of the silk polymer network in solution over a frequency range, whose upper limit is the frame capture rate of our camera, at ...
Carbons derived from the phase separation of polyacrylonitrile/solvent mixtures were investigated as lithium intercalation anodes for rechargeable lithium-ion batteries. The carbon electrodes have a bulk density of 0.35-0.5 g/cm{sup 3}, relatively low surface areas (< 10 m{sup 2}/g), and micron-size cells. Pyrolysis temperature influences the reversible lithium intercalation and the irreversible capacity (associated with the formation of the passivating layer). Carbon electrodes pyrolyzed at 600{degrees}C have first-cycle capacity as high as 550 mAh/g as well as large irreversible capacity, 440 mAh/g. Electrodes prepared at 1050{degrees}C have reversible capacities around 270 mAh/g with relatively lower capacity losses (120 mAh/g). Doping the organic precursors with phosphoric acid, prior to pyrolysis at 1050{degrees}C, leads to carbon electrodes with reversible capacities as high as 450 mAh/g. The capacity of doped carbon increased with increasing phosphorus ...
During the phases of separation, treatment, conditioning and storage of radioactive waste, destructive and nondestructive methods for their characterization are needed. In order to satisfy this necessity, in the frame of the National Program of Research and Development, the 'Laboratory for characterization of spent nuclear fuel and high/medium level radioactive waste- LABORAD' was created. The purpose of the project was to accredit the analysis methods available in the laboratory, and also to develop new methods for the characterization of the radioactive waste. A special attention was paid to the high-level radioactive waste and spent nuclear fuel characterization that require special facilities for handling. These facilities (e.g. hot cells, remote handlers, transport container) are already available in our institute. Experimental results and performances obtained during validation of the methods are presented in this paper. The laboratory (LABORAD) is notified as testing laboratory ...
Fetal nucleated cells within maternal blood represent a potential source of fetal genes obtainable by venipuncture. The authors used monoclonal antibody against the transferrin receptor (TIR) to identify nucleated erythrocytes in the peripheral blood of pregnant women. Candidate fetal cells from 19 pregnancies were isolated by flow sorting at 12 1/2-17 weeks gestation. The DNA in these cells was amplified for a 222-base-pair (bp) sequence present on the short arm of the Y chromosome as proof that the cells were derived from the fetus. The amplified DNA was compared with standardized DNA concentrations. In the case of the female fetus, DNA prepared from samples at 32 weeks of gestation and cord blood at delivery also showed the presence of the Y chromosomal sequence, suggesting Y sequence mosaicism or translocation. In 10/12 cases where the 222-bp band was absent, the fetuses were female. Thus, they were successful in detecting the Y chromosomal ...
A procedure is described for the isolation and determination of "9"0Sr, "2"2"6Ra, "2"2"8Ra and "2"1"0Pb in food. These nuclides are highly radiotoxic, above all for babies and children. Samples are dry ashed, alkali metals are removed as carbonates. Separation from other matrix ions and separation of Ra, Sr and Pb can be achieved with a column of Sr-Spec, an immobilized crown ether. For activity measurements membrane filters with SrSO_4, Ba(Ra)SO_4 and PbS are prepared. Ra is determined by gamma-spectrometry, "9"0Sr and "2"1"0Pb are determined by low-level-betacounting. The determination limits are 10 mBq/kg for "9"0Sr and "2"1"0Pb and 50 mBq/kg for "2"2"6Ra and "2"2"8Ra. The procedure is useful for all kinds of foodstuff. (orig.).
The research and development for the first year of the project are performed through specialization of researchers, information from aborad and international cooperation, securement of advanced nuclear technology, development and installation of test equipment, application of external man-power, establishment of advanced test techniques, and certified test method. 1. Absolute efficiency measurement examination technology development of gamma scanning system 2. Samplepreparation technology development of SEM and EPMA for micro-structural observation and chemical composition analysis 3. Irradiated high burn-up nuclear fuel transportation and test for PWR 4. Development of hot cell examination techniques and equipment 5. Acquirement of KOLAS system. In addition to the project, the following activities are carried out as follows; - PIE of Hanaro fuel(KH99H-001) - PIE of U-Mo advanced nuclear fuel irradiated at Hanaro - PIE of Hi-MET advanced ...
The effects of gas diffusion layer's (GDL's) anisotropic bending stiffness on the degradation behavior of polymer electrolyte membrane fuel cells have been investigated under freezing conditions. We have prepared GDL sheet samples such that the higher stiffness direction of GDL roll is aligned with the major flow field direction of a metallic bipolar plate at angles of 0^o (parallel: '0^o GDL') and 90^o (perpendicular: '90^o GDL'). The I-V performances before and after 1000 temperature cycles between -10 and 1 ^oC of 90^o GDL stack are higher than those of 0^o GDL stack, and the voltages of 90^o GDL stack are decreased slower than those of 0^o GDL stack, indicating a higher durability of 90^o GDL stack. Furthermore, the values and increasing rates of high-frequency resistance of 90^o GDL s...
MoSi_2-particulate-reinforced #alpha#-SiAlON ceramic composites 10, 20, 25, and 30 vol% were prepared by at 1,750--1,800C. The #alpha#-SiAlON matrix was of the composition (Y_0_._4_8Si_1_0_._0_0Al_2_._3_0O_1_._1_7N_1_5_._2_9). The hardness for the fully dense samples changed from HV10 = 22.5 to 15.3 GPa and the toughness from 3.2 to around 5.2 MPa#centre dot#m"1"/"2 when up to 30 vol% MoSi_2 was present. Two interesting microstructural features have been found. First, with an increasing amount of MoSi_2 a pronounced coalescence of MoSi_2 particles formed a ''dual phase'' material. The second effect was the growth of elongated #alpha#-SiAlON grains in the matrix with 10 vol% MoSi_2 added. The oxidation resistance has been determined, to be unaffected by the addition of 20 vol% MoSi_2 at 1,250 C in oxygen gas of 1 atm pressure.
US Department of Energy (DOE) Order 5400.1 requires the preparation of environmental monitoring plans and implementation of environmental monitoring programs for all DOE facilities. The order identifies two distinct components of environmental monitoring, namely effluent monitoring and environmental surveillance. In general, effluent monitoring has the objectives of characterizing contaminants and demonstrating compliance with applicable standards and permit requirements, whereas environmental surveillance has the broader objective of monitoring the effects of DOE activities on on- and off-site environmental and natural resources. The purpose of this document is to support the Environmental Monitoring Plan for the Oak Ridge Reservation (ORR) by describing the groundwater component of the environmental surveillance program for the DOE facilities on the ORR. The distinctions between groundwater effluent monitoring and groundwater surveillance have been defined in the ...
Alloy 800 is an austenitic Fe-Ni-Cr steel containing relatively minor but important amounts of carbon, aluminium and titanium. Special grades of alloy 800 known as 800H, 800HT and 800LC differ in the concentrations of these elements. In addition to these industrial specifications, further melts were prepared containing phosphorous or sulphur. Using a radioactive tracer method the bulk and grain-boundary diffusion of {sup 59}Fe was investigated in these alloys in the temperature range 800 to 1000 C. For evaluation of the diffusion profiles the approximation of Suzuoka was used, which considers the depletion of the tracer on the surface. By autoradiography it was confirmed that such depletion occurs. In alloy 800H the activation energy of grain-boundary diffusion of {sup 59}Fe was found to be (209{+-}17) kJ/mol; dissolved elements, especially phosphorous, increase the activation energy. The same materials - aged at 800 C for 100 h - were used for creep experiments at ...
Alloy 800 is an austenitic Fe-Ni-Cr steel containing relatively minor but important amounts of carbon, aluminium and titanium. Special grades of alloy 800 known as 800H, 800HT and 800LC differ in the concentrations of these elements. In addition to these industrial specifications, further melts were prepared containing phosphorous or sulphur. Using a radioactive tracer method the bulk and grain-boundary diffusion of "5"9Fe was investigated in these alloys in the temperature range 800 to 1000 C. For evaluation of the diffusion profiles the approximation of Suzuoka was used, which considers the depletion of the tracer on the surface. By autoradiography it was confirmed that such depletion occurs. In alloy 800H the activation energy of grain-boundary diffusion of "5"9Fe was found to be (209#+-#17) kJ/mol; dissolved elements, especially phosphorous, increase the activation energy. The same materials - aged at 800 C for 100 h - were used for creep experiments at 800 C ...
Trace elemental analysis was carried out in various parts of some anti-diabetic medicinal plants using PIXE technique. A 3 MeV proton beam was used to excite the samples. The elements Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr were identified and their concentrations were estimated. The results of the present study provide justification for the usage of these medicinal plants in the treatment of diabetes mellitus (DM) since they are found to contain appreciable amounts of the elements K, Ca, Cr, Mn, Cu, and Zn, which are responsible for potentiating insulin action. Our results show that the analyzed medicinal plants can be considered as potential sources for providing a reasonable amount of the required elements other than diet to the patients of DM. Moreover, these results can be used to set new standards for prescribing the dosage of the herbal drugs prepared from these plant materials.
Lubricant additives have been known to affect rolling element bearing surface durability for many years. Tapered roller bearings were used in fatigue testing of lubricants formulated with gear oil type additive systems. These systems have sulfur- and phosphoruscontaining compounds used for gear protection as well as bearing lubrication. Several variations of a commercially available base additive formulation were tested having modified sulfur components. The variations represent a range of ''active'' extreme pressure (EP) chemistries. The bearing fatigue test results were compared with respect to EP formulation and test conditions. Inner ring near-surface material in selected test bearings was evaluated on two scales: the micrometer scale using optical metallography and the nanometer scale using transmission electron microscopy (TEM). Focused-ion beam (FIB) techniques were used for TEM specimen preparation. Imaging and chemical ...
BaxSr1-xTiO3 (x=0.6, 0.75, 0.80, 0.85 and 0.9) compositions are prepared by solid-state reaction route using controlled heating and cooling. Density optimization by varying sintering temperature was achieved. X-ray diffraction (XRD) analysis shows the phase pure materials. The lattice constant decreases from 3.9868A (x=0.90) to 3.9449A (x=0.60) with increasing Sr2+; the tetragonal distortion also decreases. Dielectric constant show sharp peaks for samples having low strontium content (0.10, 0.15) and gets smeared out as the strontium content is increased (0.20, 0.25). For further higher Sr2+ composition (0.40), the dielectric peak could not be observed in the measured temperature range. The peak broadening in Sr2+ rich compositions indicates that diffused transitions and is attributed to t...
The conservation of energy through the use of the optimum economic thickness of insulation has clear benefits for industry in the U.S. Potential energy savings have been estimated to be the equivalent of 250 million of barrels of oil per year over the next decade. As is the case with any capital expenditure, the dollars spent for insulation must be expected to provide the plant owner with a certain return on his investment. This manual provides data and guidelines for estimating dollar costs and insulation life which enable the user to specify the least-cost insulation thickness based on minimum life cycle cost and required percentage return on investment. A large degree of design flexibility is provided for, so that specific economic and design criteria may be taken into account. A number of useful working aids are provided, including sample problems, forms and worksheets, and nomographs which may be used to simplify calculations. Insulation designers, ...
SiAlONs are ceramics with high potential as biomaterials due to their chemical stability, associated with suitable mechanical properties, such as high fracture toughness and fracture resistance. The objective of this work was to investigate the mechanical properties and the cytotoxicity of these ceramic materials. Three different compositions were prepared, using silicon nitride, aluminum nitride and a rare earth oxide mixture as starting powders, yielding Si_3N_4-SiAlON composites or pure SiAlON ceramics, after hot-pressing at 1750 deg. C, for 30 min. The sintered samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Furthermore, hardness and fracture toughness were determined using the Vicker's indentation method. The biological compatibility was evaluated by in vitro cytotoxicity tests. Ceramic with elevated hardness, ranging between 17 and 21 GPa, and high fracture toughness of 5 to 6 MPa ...
One of the major limitations of the nickel (Ni) - yttria-stabilized zirconia (YSZ) anode support for solid oxide fuel cells (SOFC) is its low capability to withstand transients between reducing and oxidizing atmospheres (''RedOx'' cycle), owing to the Ni-to-NiO volume expansion. This work presents results on different anode supports fabricated by tape casting. Three compositions are prepared, as the outcome of a preceding design of experiment approach. The NiO proportion is 40, 50 and 60wt% of the anode composite. The anode support characteristics like shrinkage during sintering, in-situ conductivity at high temperature, electrochemical performance and tolerance against RedOx cycles have been measured. Performance up to 0.72Wcm^-^2 (0.62V, 800^oC) is recorded for the 60wt% NiO sample on sm...
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 measurements along the bevel deliver quantitative concentration ...
Crystalline bis(O,O'-di-sec-butyldithiophosphato)platinum(II) was prepared and studied by means of 13C, 31P CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. The unit cell of the platinum(II) compound is comprised of one centrosymmetric mononuclear molecule [Pt{S2P(O-sec-C4H9)2}2], in which the dithiophosphate groups display structural equivalence in both 31P NMR and XRD data. A pair of the dithiophosphate ligands exhibit the same S,S'-bidentate chelating structural function and form two planar four-membered chelate rings, [PtS2P], in this molecule. The planar configuration of the [PtS4] chromophore in structure 1 is governed by the dsp2-hybrid state of platinum(II). The structural states of the dithiophosphate groups in two different samples of complex 1 (one crystallised from...
NaCl doped MgCl_2.nEtOH adducts were prepared by ball-milling MgCl_2.2.5EtOH with NaCl. Both the ball-milled MgCl_2.nEtOH/NaCl mixture and pure MgCl_2.2.5EtOH adducts were analyzed by X-ray diffraction (XRD), transmission electron microscope (TEM), thermogravimetry (TG) and differencial scanning calorimetry (DSC). A simple MgCl_2.nEtOH/NaCl mixture without ball-milling treatment was also studied for comparison. Two kinds of mixed crystals, Na_2MgCl_4 and NaMgCl_3, were found to be formed in a ball-milled mixture that contained 16 mol.% NaCl. TG and DSC analysis of the samples also provided indirect evidences supporting the presence of the mixed crystals in the ball-milled mixture. Adding certain amounts of NaCl in MgCl_2.2.5EtOH adduct, either by co-milling or by simple mixing, greatly increased the thermal stability of the adduct, but thermal decomposition behaviour of the ball-milled mixture was still different from that of a simple mixture.
The crystal structure and phonon densities of states (DOS) of #beta#'-SiAlON ceramics, Si_6_-_zAl_zO"zN_8_-_z (0 #<=# z #<=# 4), prepared by a novel slipcast method, are studied by neutron-scattering techniques. The samples with z < 4 form a single-phase solid solution of Si-Al-O-N isostructural to #beta#-Si_3N_4 (space group P6_3/m). A consistent preferential occupation of the 2c sites by oxygen atoms and the 6h sites by nitrogen atoms exists within this structure. The phonon DOS of #beta#'-SiAlON displays phonon bands at #approx#50 and 115 meV. These features are considerably broader than the corresponding ones in #beta#-Si_3N_4 powder.
M-type hexagonal ferrite composition, Ba(1-x)SrxFe12O19 (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), was prepared by a two route ceramic method. Complex permittivity (?'-j?'') and complex permeability (?'-j?'') have been measured using a network analyzer from 8.2 to 12.4 GHz X-ray diffraction confirmed the M-type hexagonal structure and a scanned electron micrograph was used to analyze the grain size distribution of ferrite. Substitution of Sr2+ ions causes an increase in porosity that deteriorates the electromagnetic and microstructural properties in the doped samples. Both dielectric constant and dielectric loss are enhanced in comparison to the permeability and magnetic loss over the entire frequency region. This is due to a resistivity variation and the formation of Fe2+ ions, which increases the hopping mechanism between Fe2+ and Fe3+ ions.
Careful samplepreparation and secondary ion mass spectroscopy have been used to characterize arsenic dose loss to the silicon-oxide interface. Using high resolution x-ray photoelectron spectroscopy for microprofiling, we have directly observed the pileup of arsenic at the silicon dioxide-silicon interface. At least half of the pileup is shown to be on the silicon side of the interface in the first monolayer of silicon. Monolayer chemical oxidation and etching are successfully used to profile this pileup in silicon. This pileup contains most of the arsenic dose loss that occurs during transient enhanced diffusion. This result is crucial to correctly model the dose loss and provides physical justification for using a trap/detrap model at the interface, which is necessary to account for the fact that the arsenic surface concentration remains constant during an anneal and the fact that the dose loss is partially reversible. Finally, we have found ...
Careful samplepreparation and secondary ion mass spectroscopy have been used to characterize arsenic dose loss to the silicon-oxide interface. Using high resolution x-ray photoelectron spectroscopy for microprofiling, we have directly observed the pileup of arsenic at the silicon dioxide-silicon interface. At least half of the pileup is shown to be on the silicon side of the interface in the first monolayer of silicon. Monolayer chemical oxidation and etching are successfully used to profile this pileup in silicon. This pileup contains most of the arsenic dose loss that occurs during transient enhanced diffusion. This result is crucial to correctly model the dose loss and provides physical justification for using a trap/detrap model at the interface, which is necessary to account for the fact that the arsenic surface concentration remains constant during an anneal and the fact that the dose loss is partially reversible. Finally, we have found ...
Comparisons were made between various LH and FSH radioimmunoassays currently being used to measure avian hormones. The two LH assays were the homologous chicken system of Follett et al. (1972) and the turkey assay of Burke et al. (1979). These assays were also used in heterologous arrangement by interchanging the iodinated LH fractions and antisera. Five FSH assays were analyzed: two homologous chicken systems (Scanes et al., 1977; Sakai and Ishii, 1980) an assay based on mammalian materials (rat FSH and anti-ovine FSH antiserum, and one using labelled turkey FSH (Burke et al., 1979) with an anti-chicken FSH antiserum. The potencies of purified chicken and turkey gonadotrophin preparations and of a range of plasma samples from Japanese quail were measured in each assay. The two LH systems showed some degree of species specificity, such that chicken LH was more active than turkey LH in the chicken assay, whereas the reverse was true in the ...
An aerial radiological survey was conducted from August 10-16, 1993, over a 78-square-kilometer (30-square-mile) area of the Portsmouth Gaseous Diffusion Plant and surrounding area located near Portsmouth, Ohio. The survey was performed at a nominal altitude of 46 meters (150 feet) with a line spacing of 76 meters (250 feet). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter above ground level was prepared and overlaid on a set of United States Geological Survey topographic maps of the area and an aerial photograph of the plant. The terrestrial gamma exposure rates varied from about 7 to 14 microroentgens per hour at 1 meter above the ground. Protactinium-234m was observed at six sites within the boundaries of the plant. At a seventh site, only uranium-235 was observed. No other man-made, gamma ray-emitting radioactive material was present in a detectable quantity, either on or off the plant property. Soil sample and ...
The nature of extralattice aluminum and its effect on acidity in zeolites was studied. A series of zeolites (some commercial), dealuminated by various methods, were obtained having Si/Al ratios between 1.5 and 20. These were characterized using volumetric sorption, XRD, AA, NMR, and reaction studies. Samples dealuminated using ammonium hexafluorosilicate were found to contain little or no extralattice aluminum. In contrast, steam-dealuminated zeolites had large amounts of extralattice aluminum. In some cases a significant portion of the extralattice aluminum was unobservable by [sup 27]Al NMR, suggesting the existence of an aluminum species of low symmetry. Proton NMR indicated that all the protons were associated with the lattice aluminum atoms. Depending on the preparation history, different groups of H-Y zeolites exhibited different maxima in catalytic activity as a function of aluminum content. The maxima in catalytic activity for n-pentane ...
Chromium containing amorphous hydrogenated carbon films (a-C : H/Cr) have been prepared by simultaneous rf plasma activated chemical vapour deposition of methane and magnetron sputtering of a chromium target. During deposition the substrates were heated (up to 300C) and DC biased (-200 and -600 V) in order to obtain films with high chemical stability. Constant temperature tests were performed at 250C in air with coatings deposited on silicon substrates. The degradation of the coatings was monitored by Raman spectroscopy and reflectance and transmission measurements. The main degradation mechanisms are discussed and the relevant parameters which improve the durability of the coatings are presented. Furthermore, the durability of solar selective, multilayered coatings which were deposited on copper sheets was investigated. Based on accelerated aging tests at different temperature loads in air (at 220C, 250C and 300C) and in a humid environment (80C ...
Monodisperse europium-activated titania hollow phosphors had been synthesized by a facile one-pot hydrothermal method using carbon spheres as hard templates. Samples were characterized by X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, energy dispersive spectrometer and photoluminescence spectrum. The strongest emission intensity was observed with TiO2:Eu0.2 hollow spheres and TiO2:Eu0.2 hollow spheres calcining at 550^oC. Moreover, the strongest excitation of TiO2:Eu0.2 hollow spheres transferred from 400 to 500^oC and the effective nonradiative energy transfer from the TiO2 hollow spheres host matrix to Eu^3^+ ions crystal field states was realized due to changes of crystalline field in the environment around Eu^3^+ ions occupying Ti^4^+ site...
Deposition of hard coatings may influence the mechanical properties of the bulk material and its corrosion resistance. In this work we study the hardness of the coated and the back side of 100Cr6 steel plates. Electrochemical corrosion tests were performed in O{sub 2}-saturated acetate buffer of pH 5.6 at 25degC. Chromium nitride and titanium nitride coatings prepared by different physical vapour deposition processes, such as arc, thermionic arc evaporation, magnetron sputtering and ion-beam-assisted deposition (IBAD) were compared. The results show that, for sufficient corrosion protection, chromium nitride layers have to be thicker than 500 nm. An increased nitrogen partial pressure in the evaporation chamber of the IBAD process improves the corrosion resistance significantly. The hardness of the substrates was reduced in the case of thermoionic arc evaporation only, indicating a deposition temperature of more than 250degC. For this process, however, we obtained ...
X-ray irradiation-induced paramagnetic radicals in rare earth (Ln) ion-doped glaserite and Ln ion-doped langbeinite were studied by means of ESR technique, aiming at developing the highly sensitive sensor for an ESR dosimetry. The samples were prepared by two kinds of procedures as follows. In one process, the glaserite (K{sub 3}Na(SO{sub 4}){sub 2}) matrix or the langbeinite (K{sub 2}Mg{sub 2}(SO{sub 4}){sub 3}) matrix were synthesized by heating the mixture of K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4} or the mixture of K{sub 2}SO{sub 4} and MgSO{sub 4} at 1023 K for 1 hour in He flow. The matrices obtained were mixed well with a fixed amount of Ln{sub 2}(SO{sub 4}){sub 3} (Ln=La, Eu, Gd, Lu) powder and heated at 1023 K for 1 hour in He flow. In the other process, the homogeneous mixture of a fixed amount of K{sub 2}SO{sub 4}, Na{sub 2}SO{sub 4} and Ln{sub 2}(SO{sub 4}){sub 3} powders or a fixed amount of K{sub 2}SO{sub 4}, MgSO{sub 4} and ...
Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H{sub 2}SO{sub 4}). Alloys with two nitrogen doses have been prepared (2.5x10{sup 16} and 2x10{sup 17} N atoms/cm{sup 2}). The implanted alloys have been characterized by {sup 15}N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the ...
Austenitic stainless steels (304-type) have been implanted with nitrogen ions in order to investigate the effects of implanted nitrogen on their electrochemical behaviour and on the nature of the passive film formed on the steels in acid (0.5M H_2SO_4). Alloys with two nitrogen doses have been prepared (2.5x10"1"6 and 2x10"1"7 N atoms/cm"2). The implanted alloys have been characterized by "1"5N-NRA (nuclear reaction analysis) and XPS (X-ray photoelectron spectroscopy). Alloy surfaces with well-defined N concentrations were prepared, prior to the electrochemical measurements, by argon-ion sputtering of the implanted material for a fixed time in order to reach a well-defined point on the nitrogen depth profile. The samples were then transferred without exposure to air to an electrochemical cell mounted in an inert gas glove box. The implanted nitrogen modifies the electrochemical behaviour of the alloy. The anodic dissolution ...
A series of spinel Li{sub 4}Ti{sub 5}O{sub 12} samples were synthesized via a composite molten-salt method (CMSM) using the mixtures of LiCl and KCl with different L values (L is defined as the molar ratio of LiCl:KCl) as the reaction media. It is found that the melting point of the composite molten salt can effectively influence the formation of particles, and leads to different electrochemical performances of the as-prepare Li{sub 4}Ti{sub 5}O{sub 12}. The investigations of X-ray diffraction (XRD), particle size distribution (PSD), Brunauer-Emmet-Teller (BET) surface area, and scanning electron microscopy (SEM) indicate that the as-prepared Li{sub 4}Ti{sub 5}O{sub 12} with L = 1.5 is a pure phase, and has uniform homogeneous octahedral shape particles, rather narrow PSD, and high BET surface area. Electrochemical tests show that the optimized Li{sub 4}Ti{sub 5}O{sub 12} with L = 1.5 has an initial discharge capacity of ...
Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of samplepreparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and ...