The article deals with the effects of various hazardous materials in the working environment. Some of these may be detrimental to the safety and health of the worker. The absorption of hazardous substances by the human body is discussed, as well as the effects of toxic substances. The hazardous substances are classified into the following categories: irritants, asphyxiants, anaesthetics and narcotics, carcinogens, mutagens, teratogens, systemic poisons, hazardous particulate matter and the biotransformation of toxic substances. Examples of hazardous substances include: industrial solvents, fumes and vapours, lead, mercury and uranium.
Nuclear Fuel Plant (FCN) is a facility that produces fuel bundles of CANDU-6 type for the CANDU nuclear power plant. Only natural and depleted uranium in bulk and itemized form are present as nuclear materials in this facility. Uranium and wastes from the plant are handled, processed, treated and stored throughout the entire facility. The nuclear materials with natural and depleted uranium are entirely under nuclear safeguards. The amount of uranium present in the plant in different forms and activities together with zircaloy, beryllium and other hazardous substances, wastes, explosive materials at high temperatures, etc. lead to special measures undertaken by Nuclear Safety Department (DNS) to ensure nuclear safety. Different aspects of safety are continuously monitored in the plant: operational safety, industrial safety, radiological safety, labour safety, informational safety. The emergency preparedness and response, physical protection and ...
BackgroundSubstance use and poor dietary practices are prevalent among adolescents. The purpose of this study was to examine frequency of substance use and associations between cigarette,...Full Text Available
BackgroundThe substance abuse prevention goal of the theatre production "TUNNELS" was to provide community education on substance abuse to an audience in Durham, NC and surrounding...Full Text Available
Objective:The aim of this study was to examine the relationship between truancy and escalation of substance use during adolescence and to explore potential mechanisms of this relationship.Method:Using...Full Text Available
The possibility of gamma-absorption identification of the analyzed substance is considered. the basic provisions of the proposed method are concentrated on the example of carbohydrates and hydrocarbons. The above method is tested experimentally on polyethylenes and polystyrene
The paper describes advances in statistical methods for prevention research with a particular focus on substance abuse prevention. Standard analysis methods are extended to the typical research...Full Text Available
A variety of special regulations exist in Costa Rica for registration and transport of hazardous substances; these set the requirements for entry into the country and the security of transport units. However, the regulations mentioned no specific rules for storing hazardous substances. Tax deposits have been the initial place where are stored the substances that enter the country.The creation of basic rules that would be regulating the storage of hazardous substances has taken place through the analysis of regulations and national and international laws governing hazardous substances. The regulatory domain that currently exists will be established with a field research in fiscal deposits in the metropolitan area. The storage and security measures that have been used by the personnel handling the substances will be identified to be putting the reality with that ...
Especially in bulk goods conveying, roller bearings must be selected with a vie to the intended application. Bulk goods conveying machinery consists of many different components that must interact as perfectly as possible.
average bulk water temper ature rise, OF bulk water temperature at elevation z, OF bulk water temperature in channels 0 and 1, O F film temperature, OF ...
Previous studies have shown that both bipolar disorder (BPD) and psychomotor agitation (PMA) are associated with substance dependence. These two findings have yet to be integrated, despite evidence...Full Text Available
ObjectiveTo compare the relations of social self-control and sensation seeking with substance use across samples of US and Russian adolescents.Full Text Available
ObjectivesThis studys examined the relationship between substance use disorder (SUD) and intimate partner violence screening (IPV) and management practices in the...Full Text Available
The aggregation substance (AS) of Enterococcus faecalis, encoded on sex pheromone plasmids, is a surface-bound glycoprotein that mediates aggregation between bacteria thereby facilitating...Full Text Available
ii) Flammability: (iii) A capacity to oxidise: (iv) Corrosiveness: (v) Toxicity (including chronic ...an explosion or fire: (d) For substances with corrosive properties: (i) To reduce the ...likelihood of any unintended corrosion:(ii) To control the adverse effects of any corrosion:
A method of treating bitumina and allied substances of asphaltose character includes heating the material to be treated with up to 25% of its weight of a substance of the group consisting of vegetable and animal oils and fats and fatty acids. The resulting material is heated to a temperature of about 250/sup 0/C under sufficient pressure to prevent the material escape of sulfur dioxide from the reaction mixture in the presence of a substance of the group consisting of inorganic acids of sulfur containing at least 4 oxygen atoms and their anhydrides. The heating is continued until there is no free acid left in the reaction mass.
The method and results of the quantitative gas chromatographic determination of volatile organic substances in an urban atmosphere are presented. The concentration of organic substances was determined by using a mixed adsorber consisting of graphitized thermal carbon black and activated charcoal modified by pyrocarbon. Average, maximum and minimum concentrations of constant organic components in the atmosphere of Leningrad as a typical large industrial city are reported.
This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, developed in the ...
This paper summarizes substance flow analyses for four organic substances in the City of Stockholm, Sweden: diethylhexyl phthalate (DEHP), alkylphenolethoxylates (APEO), polybrominated diphenylethers (PBDE) and chlorinated paraffins (CP). The results indicate that the stocks of APEO, PBDE and CP all are approximately 200-250 tonnes, whereas the DEHP stock is two orders of magnitude larger. Emissions can be linked to imported consumer goods such as electronics (PBDE) and textiles (APEO), and to construction materials (DEHP, CP). For several of the substances considerable amounts remain in the technosphere for a long time, even after use of the substance in new products has been eliminated. For example, the use of DEHP as plasticizer for PVC plastics in cables and floorings has more or less been phased-out, but still these applications make up a stock of some 20,000 tonnes (85% of the total DEHP stock in ...
The purpose of this study was to assess changes in dairy herd milk production and milk composition associated with changes in Salmonella contamination of bulk milk on dairy farms in southwestern Ontario....Full Text Available
The currently available propellants achieve about 95% of the combustion performance which can be expected theoretically at this time, consequently a technological breakthrough concerning new propellants have been demanded. Among high energy substances which are being studied, polymer azide which can continue combustion without relying on the oxidation reaction is a typical high energy substance to be used for a propellant of the next generation. The composite propellant which has polymer azide as fuel component and ammonium nitrate as oxidizer is considered to be the extremely promising propellant, since it provides no combution product which causes the environmental destruction. (6 figs, 4 refs)
This paper presents the effect of precursor powder size on the thermoelectric properties of sintered nanostructured bulk materials. The transport properties of the nanostructured bulk show a dramatic size effect. There are a lower thermal and electrical conductivity for the bulk with smaller nanopowders. The dimensionless figure-of merit values (ZT) of almost all the samples are much lower than those of the list reported data in the paper because the decrease in the thermal conductivity is counteracted by the reduction in the electrical conductivity and the Seebeck coefficient. The combination route of hydro/solvothermal synthesis and spark-plasma-sintering method provide a well controlled way to significantly reduce the thermal conductivity.
Prothoracic glands of tobacco hornworm larvae cultured in vitro secrete into the culture medium a substance which was active in ecdysone bioassays and determined to be ecdysone-like...Full Text Available
Some biological effects of hypoglycin-A, a compound isolated from the fruit of Blighia sapida, have been investigated. Administration of this compound to animals caused drowsiness...Full Text Available
Endogenous opioid peptides are substances involved in cell communication. They are present in various organs and tissues of the male and female reproductive tract, suggesting that they may regulate...Full Text Available
The Agency for Toxic Substances and Disease Registry (ATSDR) is a public health agency with responsibility for assessing the public health implications associated with uncontrolled releases of hazardous...Full Text Available
... The phenol and cresylic acid stream is flashed in a thin film evaporator over a concentrated sulfuric acid mixture to remove pyridine type substances ...
This poster presentation covered a number of issues related to the new regulations concerning information on new substances derived from the Canadian Environmental Protection Act (CEPA). The authors described the background, and the objectives of the research project. A brief overview of the Acid Mine Drainage (AMD) process was provided, as well as the sulphate reduction process. The general methodology was explained, and the results of the bioactivation presented. The process followed for the bioaugmentation and the results obtained were presented. The regulations concerning information on new substances derived from the CEPA were described. The authors then presented their conclusions and perspectives. 26 figs.
Substances cross the blood-brain barrier (BBB) by a variety of mechanisms. These include transmembrane diffusion, saturable transporters, adsorptive endocytosis, and the extracellular pathways. Here,...Full Text Available
Haloorganic biocides are widely employed as soil fumigants to combat the destructive action of plant parasitic nematodes and fungi. These substances are dehalogenated by soil organisms, principally...Full Text Available
A method is proposed for making a filtering material (FM) through applying bitumen or tar to a porous substance and subsequent roasting. Blast furnace slag, pumice and other inorganic substances are used as the porous substance. The method makes it possible to acquire an inexpensive filtering material with a developed surface (Pv), which replaces activated charcoal. Example. Blast furnace slag is heated to 200 to 300 degrees and with mixing is impregnated by 5 to 15 percent bitumen or tar. The impregnated slag is roasted at 800 to 1,000 degrees until full carbonization of the bitumen or tar, acquiring in this way a filtering material, which is characterized by a specific surface of 700 to 1,000 square centimeters per gram and suitable as a replacement for activated charcoal for removing organic components and heavy metals from gaseous and liquid phases. The cost of the filtering material is one eighth to one tenth of that ...
Disclosed herein is a radiation detector providing for the in situ automatic sampling of fluids containing substances emitting radiation, especially Cerenkov radiation. The detector permits sampling within well casings and is self-purging such that no additional provisions must be established for the storage and disposal of contaminated fluids.
DescriptionProgramme background Nanotechnology is the design and manufacture of substances typically between one and several hundred billionths of a metre in size. In this size range the properties of substances can change quite radically, offering potentially large socio-economic, health and environmental benefits. For example, nanofuel additives could help reduce emissions and particles from diesel engines. Nanoparticles may also be able to help remove persistent pollutants in soils and groundwaters. Th [continued...
There is increasing evidence that chemicals/test substances cannot only have adverse effects, but that there are many substances that can (also) have a beneficial effect on health. As this journal regularly publishes papers in this area and has every intention in continuing to do so in the near future, it has become essential that studies reported in this journal reflect an adequate level of scientific scrutiny. Therefore a set of essential characteristics of studies has been defined. These basic requirements are default properties rather than non-negotiables: deviations are possible and useful, provided they can be justified on scientific grounds. The 10 basic requirements for a scientific paper reporting antioxidant, antimutagenic or anticarcinogenic potential of test substances in in vitro experiments and animal studies in vivo concern the following areas: (1) Hypothesis-driven study design; (2) The nature of the test ...
Dynamics and metabolism of sugars translocated into the fruit region were investigated in tomato using {sup 14}C-labelled compounds. The translocation substance in tomato is thought to be sucrose, but the amount of sucrose in its fruit is very small. Therefore, the degradation of sucrose in the fruit and its translocation to the fruit was investigated. The sucrose was digested into hexoses such as glucose, fructose, etc. and the degradation rate was considerably low. In the stage of thickening growth, sucrose was more extensively converted into other substances except for sugars compared with the coloring stage. Then, {sup 14}C-labelled fructose was given through its gynophore to investigate the degree of reproduction to sucrose. The fructose level in the fruit reached the platean by 48 hrs after the addition and gradually decreased. The radioactivities were detected in sugars, organic acids and other alcohol soluble ...
Processing certain raw materials containing natural radioactive isotopes (e.g. U-238, Th-232 or K- 40) into products such as glas, abrasives, grinding materials or electrodes used for gasshielded tungsten-arc welding also leads to certain concentrations of industrial waste containing natural radioactive materials. Such industrial waste does not necessarily contain natural radioactive substances in concentrations exceeding the highest possible levels but nevertheless in significantly measurable quantities. This, however, frequently leads to confusion bordering on irritation by entities processing such substances as well as the general public, since they tend to believe natural radioactive substances in unobjectable concentration to cause similar or identical - health - consequences as man made radioactive substances in detrimental concentration. Radioactive materials may be incorporated intentionally or ...
Processing certain raw materials containing natural radioactive isotopes (e.g. U-238, Th-232 or K- 40) into products such as glas, abrasives, grinding materials or electrodes used for gasshielded tungsten-arc welding also leads to certain concentrations of industrial waste containing natural radioactive materials. Such industrial waste does not necessarily contain natural radioactive substances in concentrations exceeding the highest possible levels but nevertheless in significantly measurable quantities. This, however, frequently leads to confusion bordering on irritation by entities processing such substances as well as the general public, since they tend to believe natural radioactive substances in unobjectable concentration to cause similar or identical - health - consequences as man made radioactive substances in detrimental concentration. Radioactive materials may be incorporated intentionally or ...
A route, as followed by ECN, is described for development of SiN{sub x}:H layers deposited by microwave (MW) PECVD, which are suited for surface and bulk passivation of mc-Si solar cells. First research was focussed on surface passivation and this resulted in the development of SiN layers that were Si-rich and where the hydrogen is mainly bonded to silicon atoms. A disadvantage of such Si-rich layers is their large absorption at shorter wavelengths, which make them unsuitable as front side AR coatings. Further, these layers appeared to be less suitable for bulk passivation. The next step therefore was the development of SiN layers for bulk passivation. For good bulk passivation of solar cells by means of a thermal anneal of the SiN layers, we found that SiN layers with high N-H bonding concentrations are required. Fine-tuning of the deposition conditions of these layers, finally resulted in the ...
This paper explores the potential of combining substance-flow modelling with water and wastewater sampling to trace consumption-related substances emitted through the urban wastewater. The method is exemplified on sucralose. Sucralose is a chemical sweetener that is 600 times sweeter than sucrose and has been on the European market since 2004. As a food additive, sucralose has recently increased in usage in a number of foods, such as soft drinks, dairy products, candy and several dietary products. In a field campaign, sucralose concentrations were measured in the inflow and outflow of the local wastewater treatment plant in Linkoping, Sweden, as well as upstream and downstream of the receiving stream and in Lake Roxen. This allows the loads emitted from the city to be estimated. A method c...
The separation of humic substances by polysulfone has been done. Thisinvestigation aims at separating the humic substances contained in theestuary environment. Because of without sample pre-treatment, cheap and easythis method has been to choice. At preliminary study proved that byincreasing the pressure until 50 psia, the yield of flux was 13.5 l/m"2.jamand the reject coefficient was 90.98%, so that polysulfone membrane isappropriate to be applied. More over the pressure could be increased morethan 50 psia. The feed concentration should be lower than 150 ppm, though thevolume should be greater. The pH condition should be alkaline (pH> 7), sinceat this condition the filtration process is easily conducted and the rejectcoefficient could reach 95.09%. (author)
Iron is an essential element to marine biota. Different types of dissolved organic matter (DOM), such as humic substances have impacts on the marine coastal waters iron chemistry.The aim of the study was to examine how the presence of humic substances (both aquatic and sedimentary) may affect iron bioavailability to the bloom-forming cyanobacterium Microcystis aeruginosa Kutzing incubated on standard and modified mineral BG-11 media. The final iron concentrations in the growth media ranged from 0.1 to 100mM.The results demonstrate that both the growth rate and the concentration of chlorophyll a in cultures of M. aeruginosa are limited by insufficient (a 15-fold as compared with the cultures exposed to iron only at the same concentration. Sedimentary humic acids in the presence of iron at a...
Labelling of "1"4C-M-ISP and its absorption, translocation and distribution in peanut and soybean seedling were studied. The results of experiments showed that the radioactive substance could be translocated in xylem and phloem of two kinds of plants. The root of peanut seedling absorbed "1"4C-M-ISP from the nutrient solution more strong than the root of soybean seedling did. After leaf treatment with "1"4C-M-ISP, the soybean seedling absorbed more radioactive substance than peanut seedling did. But the translocation's speed of radioactive substance in pnloem of two kinds of plants were similar.
Waste cooking oil can be recovered and processed into animal feed additives after purification. Unfortunately, the traditional purification processes are insufficient for the removal of the harmful compounds formed during frying, mainly about malondialdehyde and other 2-thiobarbituric acid reactive substances. In the present paper, firstly, a simple and reliable HPLC method was developed to measure the content of malondialdehyde in purified waste cooking oil. The detection limit and the standard recovery of the analysis method are 1.20x10-5gl-1 and 96.5-99.2%, respectively, which is accurate and valid enough for the detection of malondialdehyde in waste cooking oil. Furthermore, the removal of malondialdehyde and other 2-thiobarbituric acid reactive substances from waste cooking oil was in...
The contents of polycyclic aromatic hydrocarbons (PAH) and phenolic substances in Frankfurter-type sausages were investigated depending on hot smoking conditions (glow smoke). For the 24 smoking experiments (performed in duplicates) three different smoke densities and ventilator velocities as well as wood chips with five different moisture contents were tested. During the smoking process, concentrations of O"2, CO"2 and CO, humidity and temperature in the smoking chamber as well as smoke generation temperature were determined. The chemical analysis included the contents of the 15+1 EU priority PAH and the phenolic substances guaiacol, 4-methylguaiacol, syringol, eugenol and trans-isoeugenol. The smoking conditions had a significant influence on smoke generation temperature, organoleptic pr...
... and facilities; the physical processing of materials into products; and processes associated with ... area of bulk silicon prod! uction as wafer material has been omitted, in keeping with current ...
This paper aims to provide a comprehensive review of the various models or simulations for predicting drug release from bulk-degrading systems. A brief description of bulk degradation processes and factors affecting the degradation rate, and consequently the release kinetics, is presented first. Next, several important classical models, often used as the basis for subsequent model development, are discussed. Both mathematical models and Monte-Carlo based simulations have been developed for controlled release from bulk-degrading systems. The mathematical models can be further subdivided into two categories. First, the diffusion-based models whose transport mechanism is mainly governed by diffusion, but with degradation-dependent diffusion coefficients. These are generally simpler and easier...
measure meteorological variables and bulk water temper- ature. The locations of the buoys are given in Table 1. TB2 and TB3 were moved slightly farther south ...
Alkylphenols are widely used as plastic additives and surfactants. We report the identification of an alkylphenol, nonylphenol, as an estrogenic substance released from plastic centrifuge tubes. This...Full Text Available
ObjectivesUse of prescription opioids for chronic pain is increasing, as is abuse of these medications, though the nature of the link between these trends is unclear....Full Text Available
Cysticercosis is an infection with larval cysts of the cestode Taenia solium. Through pathways that are incompletely understood, dying parasites initiate a granulomatous reaction that,...Full Text Available
Chronic pain patients who show aberrant drug-related behavior often are discontinued from treatment when they are noncompliant with their use of opioids for pain. The purpose of this study was...Full Text Available
This research focuses on young Mexican American girls who are not formal gang members yet participate in street-based activities of male gangs and engage in risk behaviors. These females comprise...Full Text Available
Carbenoxolone (CBX) is a semisynthetic derivative of the licorice root substance glycyrrhizinic acid and has been previously reported to induce only heat shock protein 70 [Hsp70, HSPA1A (the systematic...Full Text Available
Thirty chemicals or substances currently undergoing long-term carcinogenicity bioassays in rodents have been used in a project to further evaluate methods and information that may have the capability...Full Text Available
Benzidine (4,4'-diaminobiphenyl) is a known human carcinogen; exposure to this substance resulted in an epidemic of bladder cancer among workers in the dye industry in Europe and North America. The...Full Text Available
Mixtures of organic-inorganic substances are studied for their performance as energy storage media. Use is made of the fact that organic substances give higher amounts of energy but within a wide range of temperature on the one side and the fact that inorganic substances give lower amounts of energy at constant temperature on the other side. Mixtures of both types of substances, in different ratios, are investigated for the object of determining that optimum composition which stores a higher amount of energy and, meanwhile, releases it at a constant temperature or within a narrow range of temperature. The mixtures used are composed of Glauber`s salt (Na{sub 2}SO{sub 4}.10H{sub 2}O) and stearic acid in different proportions. The effect of cooling fluid flow rate and ambient temperature as well as the effect of addition of a nucleating agent is studied. The results showed that the highest amount of energy ...
Reliable values of x-ray and gamma-ray attenuation coefficients of elements and compounds are required in spectrometry as well as in many other scientific, engineering and medical disciplines involving photon radiation
This paper presents the results of a meta-analysis for a single investigator examining the effectiveness of the modified therapeutic community (MTC) for clients with co-occurring substance use...Full Text Available
Investigation of Interaction of Laser Radiation with Radioactive Deposits on the metal Surface and Creation of Experimental Stand for Development of Laser Technology for Remote Treatment of Materials Contaminated with Radioactive Substances at the Atomic Power Plants
The soluble subcellular fraction of a chlB mutant contains an inactive precursor form of the molybdoenzyme nitrate reductase, which can be activated by the addition to the soluble fraction of protein...Full Text Available
SummaryConvection-enhanced delivery (CED) of substances within the human brain is becoming a more frequent experimental treatment option in the management of brain tumors, and...Full Text Available
Basic research in relation to a complete utilisation of animal substances as an alternative to a thermal disposal was done. The composition of different kinds of bones were investigated as well as their amounts which are available. Conventional utilisation was opposed to the innovative utilisation. Technologies will be selected which should be developed, because they have the chance in the case of a fast industrial realisation to get a good profit. There is a global requirement for the technologies which are developed and their products which can be produced with this. The raw material basis is available in the necessary scale in nearly all countries. (orig.) [German] Grundlegende Untersuchungen zur ganzheitlichen Verwertung von tierischen Substanzen als Alternative zur thermischen Entsorgung wurden durchgefuehrt. Es wurde die Zusammensetzung der verschiedenen Knochenarten und ihr Aufkommen untersucht. Die konventionelle wurde der innovativen Verwertung ...
The adaption of the Muster-VAwS (model ordinance on the handling of water endangering substances in plants and specialized facilities) in the ordinances of the different German states, means that the legislator has laid down concrete - technical and organizational - requirements concerning the handling of water-endangering substances for all plants. The present example of the systematic stocktaking of all environmentally relevant substances in the context of the operation of the pumped storage plants of Schluchseewerk AG, Freiburg, an the application of the model operating instructions for hydropower plants shall serve to illustrate two important aspects for the implementation of this extensive ordinance. (orig.) [Deutsch] Durch Umsetzung der Muster-VAwS (Muster-Verordnung ueber Anlagen zum Umgang mit wassergefaehrdenden Stoffen und Fachbetriebe) in entsprechende Laenderverordnungen wurden durch den Gesetzgeber konkrete ...
Lumbricus terrestris (Annelid, Oligocheta) is capable of cellular- and humoral-specific reactions against natural antigens. Is this earthworm able to elaborate a response of antibody type against a...Full Text Available
The report deals with the energy consumption of traffic and its emissions of hazardous substances into the air, and stresses the advantages of the electric car with respect to energy consumption and noise generation. 5 figs., 3 refs.
Electronic waste or e-waste is one of the rapidly growing problems of the world. E-waste comprises of a multitude of components, some containing toxic substances that can have an adverse impact on human...Full Text Available
The hepatic uptake rate for certain albumin-bound drugs and metabolites correlates poorly with their equilibrium unbound concentration in the plasma, suggesting that binding equilibrium may not always...Full Text Available
The liver plays a vital role in glucose homeostasis, the synthesis of bile acids and the detoxification of foreign substances. Liver culture systems are widely used to test adverse effects of drugs...Full Text Available
Requirements for food packaging materials include whether there is any interaction between the food and the package during or after the irradiation, and whether as a result of the irradiation, volatile or leachable substances are released from the pack into the food. The performance of cellulose-based materials and plastic films under irradiation are discussed.
BackgroundWith the phasing out of ozone-depleting substances in accordance with the United Nations Montreal Protocol, phosphine remains as the only economically viable fumigant for...Full Text Available
Toluene diisocyanate (TDI) and methylene diphenyldiisocyanate (MDI) are used in large quantities in the polyurethane foam manufacturing industry. Both substances are mutagenic and at least TDI is carcinogenic...Full Text Available
The tendency for some individuals to partake in high-risk behaviors (eg, substance abuse, gambling, risky sexual activities) is a matter of great public health concern, yet the characteristics and neural...Full Text Available
BackgroundNormal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. Organisms have evolved...Full Text Available
Albumin is a multifunctional transport protein that binds a wide variety of endogenous substances and drugs. Insulins with affinity for albumin were engineered by acylation of the epsilon-amino group...Full Text Available
Botulism is caused by the botulinum neurotoxins (BoNTs), the most poisonous substance known. Because of the high potency of BoNT, development of diagnostic and therapeutic antibodies for botulism requires...Full Text Available
Object: To provide a tank, which can safely and reliably accommodate high temperature sodium containing radioactive substance in case of occurrence of an accident in a sodium system and thus prevent spread of contamination. Structure: A sodium drain duct inserted into a tank from above the tank is provided at the position of its lower end with a buffer means for preventing direct flow-down of sodium to a bottom plate. A means for preventing the discharge of radioactive substance to the cover gas is provided above the lower end of the sodium drain tube so as to surround the sodium drain tube. (Kamimura, M.).
Water-soluble, ethanol-insoluble extracts prepared from several medicinal herbs of the Araliaceae and other families were tested for their radioprotective activity by either measuring 30 days survival rates (a commonly applied method) or counting the thrombocytes 14 days after irradiation (an improved method) in mice. The extracts were i.p. injected once within 4 min after the whole body X-ray irradiation. Of 12 materials examined, Aralia elata, Angelica acutiloba and Morus bombysis seemed to be good starting materials for preparing radioprotective substance(s) because of their relatively high specific activity and high yields of the extracts. (author).
Heat-of-fusion storage materials for low temperature latent heat storage in the temperature range 0-120 C are reviewed. Organic and inorganic heat storage materials classified as paraffins, fatty acids, inorganic salt hydrates and eutectic compounds are considered. The melting and freezing behavior of the various substances is investigated using the techniques of Thermal Analysis and Differential Scanning Calorimetry. The importance of thermal cycling tests for establishing the long-term stability of the storage materials is discussed. Finally, some data pertaining to the corrosion compatibility of heat-of-fusion substances with conventional materials of construction is presented.
Preparation and electrocatalytic reactions of nano porous materials in biodegradable fluids were studied. Electrochemical etching was conducted to selectively extract metallic elements from alloys to form porous structures. Electrocatalytic properties of the porous electrodes were characterized. Comparative studies on the electrochemical activities of the nano porous metallic electrodes with bulk metallic wire catalysts were performed. It is found that the current density at the nano porous electrode is three times higher than that of the bulk electrode
We study certain supersymmetry breaking deformations of linear dilaton backgrounds in different dimensions. In some cases, the deformed theory has bulk closed strings tachyons. In other cases there are no bulk tachyons, but there are localized tachyons. The real time condensation of these localized tachyons is described by an exactly solvable worldsheet CFT. We also find some stable, non-supersymmetric backgrounds.
We present the first results from tests of a MICROMEGAS detector manufactured using the so-called "bulk" technology and having a resistive cathode mesh instead of the conventional metallic one. This detector operates as usual MICROMEGAS, but in the case of sparks, which may appear at high gas gains, the resistive mesh reduces their current and makes the sparks harmless. This approach could be complementary to the ongoing efforts of various groups to develop spark-protected MICROMEGAS with resistive anode planes.
This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.
In order to obtain knowledge about formation and growth of condensed ring structure in a coalification process, discussions were given on product skeleton structure by using hydrogenation and hydrocracking of heated cellulose. In underwater heating of cellulose, reaction of dehydration has occurred at 200{degree}C or lower, that of decarbonation at 250{degree}C or higher, and that of demethanizing at 300{degree}C, resulting in production of a dark-brown coal-like substance. The substance has lower H/C value and higher O/C value than coal. As the underwater heating temperature rises, the hydrogenation reactivity of the heated substance decreases, and so does the ratio of conversion into toluene solubles. These phenomena are related to strength of cross-linking bond between unit skeleton structures. A substance heated at an underwater heating temperature of 200{degree}C turns toluene-soluble almost ...
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.
The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to pulsed magnetic fields is calculated by using small sets of finite elements. Some comparisons with experimental results are provided, and they give confidence in the modelling of the superconducting properties. Transient magnetizations as a function of time and space as well as shapes and absolute values of trapped magnetic flux profiles are presented. The influence of the sample geometry is investigated for different millisecond pulsed magnetization processes. Results are reported for different radial thicknesses and heights, different pulse durations, peak magnetic fields and pulse sequences with and without stepwise cooling. Comparisons concerning the achievable trapped magnetic field and flux are made, and implications for the use of high-temperature superconductor bulk parts as cryo-permanent magnets in potential applications like electric machinery are discussed.
Epitaxial films grown pseudomorphically on substrates provide a way to stabilise non-equilibrium structures of materials. Obviously, there always is a certain lattice misfit between substrate and film material in its bulk equilibrium structure. In the pseudomorphic regime, this misfit can either lead to the growth of films in a strained bulk structure or even yield structures that are not stable in the bulk. Large misfits do not necessarily imply large lateral stress. Theory can help to predict e.g. geometry, stress and magnetic properties of pseusomorphically grown metal films. In this work, we considered the fcc-bcc epitaxial Bain path of 3d, 4d, and 5d transition metals, which provides a reasonable description of tetragonally distorted films on substrates. We carried out density functional calculations in the implementation of the full potential local orbital program package FPLO. Emphasis is put on similarities among ...
The thermal properties (thermal conductivity, thermal diffusivity, thermoelectric power, thermal dilatation, etc.) and the mechanical properties (Young's modulus, strength, hardness, fracture toughness, etc.) have been measured at low temperatures (4-300K) and under a high magnetic field (0-10T) for about 50 REBaCuO bulks (RE=Y, Gd, Nd, Sm, Dy, etc.). We have constructed the database of these properties and opened it on the Web site (thermal properties: http://ikebehp.mat.iwate-u.ac.jp/database.html and mechanical properties: http://paris.mech.iwate-u.ac.jp/sc-bulk/database.html). The influence of the species of RE ions, the content, size and dispersion of the RE211 (or Nd422) phase and Ag particles and the defects distribution on these properties is characterized.
Since the 1950s a transport revolution has occurred comparable to events in the late nineteenth century when sailing ships were replaced by steam vessels. Freight rates for bulk products have decreased 65-70% due to improved maritime technology, and formerly separate markets for bulk products have been unified globally. It is suggested that the low freight rates since the early 1980s will level out in future. Price peaks caused by political and military crises like the Korean war, the Suez crisis, OPEC I and OPEC II also seem to be of diminishing importance over time. The world market has become much less sensitive to external shocks due to alternative sources of supply and alternative transport routes. Examples are given from the coal, grain and iron ore international market. 62 refs., 24 figs., 4 tabs.
In the present work, bulk amorphous and nanocrystalline Al83Fe17 alloys were obtained by consolidation of mechanically alloyed powders. Mechanical alloying of Al-17% Fe powder mixture yielded powder with an amorphous structure. Thermal behaviour of the milling product was examined using differential scanning calorimetry. This investigation revealed that the amorphous phase crystallised above 380^oC. The amorphous powder was compacted under a pressure of 7.7GPa in different conditions: at 380^oC for 600s and at 1000^oC for 180s. Structural investigations of the bulk material revealed that the amorphous structure was retained after consolidation process applied at 380^oC. Compaction under high pressure at 1000^oC caused crystallisation of the amorphous phase and appearance of metastable nano...
In general relativity, the fields on a black hole horizon are obtained from those in the bulk by pullback and restriction. Similarly, in quantum gravity, the quantized horizon degrees of freedom should result from restricting, or pulling-back, the quantized bulk degrees of freedom. This is not yet fully realized in the - otherwise very successful - quantization of isolated horizons in loop quantum gravity. In this work we outline a setting in which the quantum horizon degrees of freedom are simply components of the quantized bulk degrees of freedom. There is no need to quantize them separately. We present evidence that for a horizon of sphere topology, the resulting horizon theory is remarkably similar to what has been found before.
We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small particles. The Pd-Ag nanowires alloy similar to previously reported spherical Pd-Ag particles of similar diameter and composition.
Bundling of axons and capillarization of the neuroepithelium represent two of the numerous important events in brain development. Prerequisite for these two processes is a directed growth in the matrix-containing intercellular space before a final pattern is formed. The formation of the optical nerve in the region of the retina served as example to show that an extracellular substance with adhesive properties, the glycoprotein fibronectin, plays an important role during bundling and directed growth the axons. However, only small amounts of fibronectin are detected in the region of the capillary sprouts that penetrate into the neuroepithelium. In this area other substances, especially basement membrane components are present, e.g. for anchorage and stabilization. Hence, intercellular substances are also involved in the morphogenesis of the brain. Brain development comprises a great number of individual steps. Their knowledge ...
Weight loss measurements were performed in 20% and 28% hydrochloric acid at 90/sup 0/C on carbon steel, 22Cr5Ni duplex stainless steel, and two superaustenitic steels - 27Cr31Ni3Mo and 19Cr25Ni4Mo -, in presence of organic substances used singly or mixed. The organic substances examined were quaternary ammonium salts (1-4-pyridyl)-pyridinium chloride hydrochloride, dodecylpyridiniumchloride, benzyldimethylstearylammonium chloride, and dodecyltrimethylammonium bromide), alkynols (1-octyn-3-ol, propargyl alcohol) and trans-cinnamaldehyde. The synergistic effect of potassium iodide on the inhibitive efficiency of the organic substances was studied. The variations of corrosion rate during the test time (normally six hours) were recorded by means of polarization resistance measurements. Polarization curves were also recorded. The results showed that the corrosion rates of the four steels examined can be reduced to less than 1 ...
In order to evaluate the effects of radioactivity on active vegetal substances, samples of Fennel (Foeniculum vulgare Miller., fructus), Guarana (Paulinia cupana, Kunth, semen), Gingko (gingko biloba, L., folium), and Kawa-Kawa (Piper methysticum G. Forst, rhizoma), were treated with scaling doses (0 to 25 KGy) of gamma radiation (Co{sup 60}). The 'blind test' methodology was used. The active substances from each sample were analysed by qualitative and quantitative methods after radiation. There were no significant differences seen between the control sample (0 KGy) and the irradiated samples. Microbe contamination was significantly reduced, about 10000 CFU/g, with the initial 5 KGy dose. It was concluded that gamma radiation can be used as an alternative procedure to reduce microbiologic contamination in medicinal plants. Before this procedure can be extended to other medicinal plants, more specific analytical methods are ...
In order to develop a high-efficiency coal pyrolysis method, flash pyrolysis was experimented on slurry prepared by using liquid-phase oxidation reformed coal and a methanol-based solvent mixture. Australian Morwell coal was used for the experiment. The oxidized coal, into which carboxyl groups have been introduced, has the condensation structure relaxed largely, and becomes highly fluid slurry by means of the solvent. Char production can be suppressed by making the oxidation-pretreated coal into slurry, resulting in drastically improved pyrolytic conversion. The slurry was divided into dissolved solution, dried substance, extracted residue, and residual slurry, which were pyrolized independently. The dissolved solution showed very high conversion. Improvement in the conversion is contributed by separating the dissolved substances (coal macromolecules) at molecular levels, coagulating the molecules, suppressing cross-link formation, and ...
With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations ...
The risk assessment report for gasoline was discussed at the EU TCNES (Technical Committee for New and Existing Substances) on 1 December 2004. CONCA WE was represented at the meeting by Tom Parkerton (EMBSI), Peter Boogaard (Shell),Jan Urbanus (CONCA WE) and Duncan King (BP). First a short introduction to CONCAWE was given, followed by a summary of the on-going programme of risk assessments on groups of petroleum substances. The methodology and outline conclusions for the environmental and health risk assessment for gasoline were then presented. Member States were invited to comment on the draft risk assessment. It was clear that not ail of the Member States had yet reviewed the report in detail (it had been circulated to the Member States approximately 5 weeks in advance of the meeting). However, those that did provide comments (along with ail of all European Chemicals Bureau representatives) were ail very supportive of the CONCAWE ...
The representative result as the global environmental problems caused by chemical substance is the ozone layer depletion of the stratosphere by chlorofluorocarbon (CFC). The regulation of the CFC began in 1989 based on 'Vienna Convention for the Ozone layer protection' (1985) and 'Montreal Protocol on Substances that Deplete the Ozone Layer' (1987). Production and consumption of CFC, tetrachloromethane, methylchloroform and halon have already been aborted, and the regulation of HCFC and bromomethane were also began to turn to the abolition. The increase of atmosphere average concentration such as CFC and methylchloroform has already blunted in such the international regulation. The chloride concentration of stratosphere from substance of the ozone layer depletion would reach a peak soon, and was prospected to be reduced after then. It is expected to drop to previous level before the South ...
The activated charcoal treatment in the field of the water treatment is applied to water supply, sewage, industrial water supply and industrial sewage, etc.. Its main treatment effects are (1) decolorization, (2) removal of odorous substance, (3) removal of organic material which is detected as COD or BOD, (4) removal of harmful substance, (5) removal of substance which could generate muddness and tarnish and (6) removal of organic material which affects the succeeding high degree treatment badly, etc.. Many actual application examples in the above fields have been reported. As the most recent topic, a big amount of the demand of activated charcoal is expected in the treatment of water supply. Chlorine which is used as disinfectant during the water purification process generates organic halogen compounds such as trihalomethane through the reaction with precursor such as humic acid. The countermeasure therefore is being ...
A preliminary chemical characterization is presented of phosphate-free aminolipids isolation from Chlorobium limicola f. thiosulfatophilum. The lipid contains no phosphorus, glycerol, sugar, ornithine, or lysine. Ultraviolet absorption and fluorescence spectra indicate that the amino moiety of the lipid is an aromatic heterocyclic compound. Infrared spectra indicate that the lipid is a secondary or tertiary amide, and gas chromatograhic analysis of the hydrolyzed lipid shows that for each 1100 g of lipid, 1 mol of myristic acid (C/sub 14:0/) is linked in an amide bond. Acid hydrolysis of the lipid yields two fluorescent substances, A (ninhydrine positive) and B (negative), in addition to myristic acid. Proton nuclear magnetic resonance (NMR) studies indicate that substance A contains a butyl groups attached to a conjugated ring carbon, two equivalent ethyl groups attached to one or two nitrogen atoms, and two downfield protons (8.4 ppm), ...
The PVSCAN is an instrument designed to characterize silicon solar cell materials and devices. It performs a host of measurements that yield spatial maps of dislocation density, grain distribution, reflectance, and photoresponses from near-junction and the bulk of a solar cell.
When liquids are confined in nano-scopic dimensions, their properties differ from the corresponding bulk liquid, due to their reduced dimensionality and surface effects. Phase transition temperatures and pressures are often shifted from the bulk values and new phases can appear due to the strong interactions of the molecules with the confining walls. We have studied the structural and dynamical properties of aromatic liquids such as benzene, toluene, and ortho-terphenyl confined in nano-porous materials, MCM-41 and SBA-15, synthesized and characterized in our laboratory. A non-trivial dependence of the glass transition temperature, Tg, on the pore size and surface treatment of nano-porous materials is confirmed and interpreted as resulting from a competition between the fluid-wall and fluid-fluid intermolecular interactions. An increase of Tg is observed for small pore sizes and attractive surface while Tg decreases for non attractive surface, ...
If bone strength was the only requirement of skeleton, it could be achieved with bulk, but bone must also be light. During growth, bone modelling and remodelling optimize strength, by depositing bone...Full Text Available
The bulk alignment of actin filament sliding movement, powered by randomly oriented myosin molecules, has been observed and studied using an in vitro motility assay. The well established,...Full Text Available
Hole mobility changes under uniaxial and combinational stress in different directions are characterized and analyzed by applying additive mechanical uniaxial stress to bulk Si and SiGe-virtual-substrate-induced strained-Si (s-Si) p-MOSFETs (metal-oxide-semiconductor field-effect transistors) along (110) and (100) channel directions. In bulk Si, a mobility enhancement peak is found under uniaxial compressive strain in the low vertical field. The combination of (100) direction uniaxial tensile strain and substrate-induced biaxial tensile strain provides a higher mobility relative to the (110) direction, opposite to the situation in bulk Si. But the combinational strain experiences a gain loss at high field, which means that uniaxial compressive strain may still be a better choice. The mobility enhancement of SiGe-induced strained p-MOSFETs along the (110) direction under additive uniaxial tension is explained by the ...
Responsibility for the operation and maintenance of the bulk of the 132 kV cable network in England and Wales was transferred from the CEGB to the area boards in the 1970s. Norweb has successfully dealt with the increase in work using in-house expertise exclusively.
Semiconductor nanocrystals smaller than the bulk exciton show substantial quantum confinement effects. Recent experiments including Stark effect, resonance Raman, valence band photoemission, and near edge X-ray adsorption will be used to put together a picture of the nanocrystal electronic states.
This report describes an investigation of the factors affecting disintegration time in the mouth (DTM) of rapidly disintegrating tablets. The relation between DTM and stationary time of upper punch displacement (STP) was examined using a tableting process analyzer (TabAll). Results indicated that the bulk density of mixed excipient powder used for tablet preparation affects both DTM and STP. As the value of bulk density increased, STP became longer and DTM shorter. The results of a combination of granules and powder with or without a drug showed liner relation between apparent volume (reciprocal of bulk density) and DTM (r(2)=0.7332). For a DTM less than 60 s, a formulation with a bulk density greater 0.5 g/mL should be chosen with a compression force of 5 kN. The hardness of tablets could be greater than 3 kg if at least one high-compressibility excipient was used in the formulation. PMID:18804156
Eu 4f electronic structures of a temperature-induced valence transition system EuPd{sub 2}Si{sub 2} have been investigated by bulk-sensitive high-resolution photoemission spectroscopy at temperatures from 20 to 300 K. The bulk Eu{sup 2+} 4f component is definitely distinguished from two surface Eu{sup 2+} 4f components. The changes in the spectral intensity of the bulk Eu{sup 2+} and Eu{sup 3+} 4f configurations and in the energy separation between these states are observed in the temperature dependent photoemission spectra. These temperature dependences are related to the valence transition of EuPd{sub 2}Si{sub 2}. The Eu mean valence is evaluated to be 2.75{+-}0.03 at 20 K and 2.30{+-}0.05 at 300 K. These values are in good agreement with those evaluated from Moessbauer and Eu L{sub III}-edge X-ray absorption measurements.
Cortical bone contributes the majority of overall bone mass and bears the bulk of axial loads in the peripheral skeleton. Bone metabolic disorders often are manifested by cortical microstructural changes...Full Text Available
Using an ab initio pseudopotential method within a generalized gradient approximation of the density functional theory, the structural, electronic, and phonon properties of SrS in the B1 (NaCl) and B2 (CsCl) structures have been studied. The calculated lattice constants, static bulk modulus, and first-order pressure derivative of the bulk modulus are reported for both the B1 and B2 structures and compared with previous experimental and theoretical calculations. Electronic band structures and densities of states have been derived for SrS. Subsequently, a linear-response approach to the density functional theory is used to derive the phonon frequencies and densities of states.
'The interactions of carbon tetrachloride with strongly basic oxides and hydroxides have been studied by several techniques in order to understand the surface reactions and the subsequent bulk reactions that result in the destruction of the chlorinated hydrocarbon. Emphasis has been placed on understanding the surface phases, as well as the bulk phases, that are present during these transformations. As a result of the study with barium oxide, a reaction cycle has been demonstrated that may have practical significance in the removal of chlorinated hydrocarbons.'
Band-structure studies of NbN and VN are reported. The results of angle-resolved photoemission experiments performed on NbN/sub 0.93/ and VN/sub 0.89/ are presented. The bulk-band structures calculated for stoichiometric NbN and VN using the linearized augmented-plane-wave method are presented and utilized in the interpretation of the experimental spectra. It is shown that most of the features in the spectra can be accounted for by direct bulk-band transitions. A fairly good agreement between experimental and calculated band locations and dispersions is obtained.
The Cu- and Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of a mixture of gas-atomized metallic glass powders and ductile brass powders. The brass powders added for the enhancement of plasticity are well distributed in the matrix after consolidation. The matrix of the composite materials remains as a fully amorphous phase after consolidation process. With increasing the brass content, the level of plasticity strain increased, although the level of strength decreased. The successful consolidation of metallic glass matrix composite with high density was attributed to viscous flow in the supercooled liquid state during spark plasma sintering.
A multi-technique approach was employed to study a decorated Egyptian wooden sarcophagus (XXV?XXVI dynasty, Third Intermediate Period), belonging to the Museo del Vicino Oriente of the Sapienza University of Rome. Portable non-invasive unilateral NMR was applied to evaluate the conservation state of the sarcophagus. Moreover, using unilateral NMR, a non-invasive analytical protocol was established to detect the presence of organic substances on the surface and/or embedded in the wooden matrix. This protocol allowed for an educated sampling campaign aimed at further investigating the state of degradation of the wood and the presence of organic substances by 13C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. The composition of the painted layer was analysed by optical micr...
The primary UK legislation relating to the use of radioactive materials are the Radioactive Substances Act 1993 (RSA, 1993) and the Ionising Radiations Regulations 1999 (IRR, 1999). These implement the European Union's Basic Safety Standards Directive (EUBSS) (EC, 1996). The Radioactive Substances Act 1993 (RSA93) regulates the accumulation, storage and disposal of radioactive waste, principally to control potential doses to members of the public. The Ionising Radiations Regulations 1999 (IRR, 1999) deal primarily with regulating the doses that people receive at work. Both of these pieces of legislation apply to the use of materials containing naturally occurring radionuclides. Historically UK regulations relating to radioactive materials have covered both artificial and natural radionuclides
Many power plants use treated surface water as boiler feedwater and have difficulties in keeping within the limits for organic substances in feedwater (TOC < 200 ppb) or acid conductivity in steam condensate (< 0.2 {mu}S/cm). The characteristics of surface water and the role of organic substances in boiler feedwater are explained and discussed. [German] Viele Kraftwerke bereiten fuer die Erzeugung von Kesselspeisewasser Oberflaechenwasser auf und haben Probleme, die Richtlinien fuer organische Stoffe im Speisewasser (TOC < 200 ppb) oder Saeure-Leitfaehigkeit in Dampfkondensaten (< 0,2 {mu}S/cm) einzuhalten. Die besonderen Eigenschaften von Oberflaechenwaessern und die Bedeutung organischer Stoffe in Kesselspeisewasser werden erlaeutert und diskutiert. (orig.)
A localization criterion for the crystal-liquid phase transition (PT) is suggested, according to which the PT starts when the ratio E d/k B T reaches a boundary value E d(s)/k B T m, above which a solid phase, and below which, a liquid phase is located in the phase diagram. Here, E d is the energy of the delocalization of an atom, k B is the Boltzmann constant, T is the temperature, and E d(s) is the energy of delocalization for the solid phase at the melting point T m. It is shown that this criterion extends the Lindemann criterion of melting to the case of crystallization, and the L?ven criterion of crystallization to the case of melting. It is shown that the localization criterion suggested is applicable both for the normally melting substances and for the substances melting with a decr...
A localization criterion is proposed for the crystal-liquid phase transition (PT). According to this criterion, the PT begins when the E d/k b T ratio reaches a boundary value E d(s)/k b T m such that a solid phase is present above it and a liquid phase is present below it in a phase diagram. Here, E d is the energy of atom delocalization, k b is the Boltzmann constant, T is the temperature, and E d(s) is the delocalization energy for a solid phase at melting point T m. This criterion is shown to generalize the Lindemann criterion of melting to the case of crystallization and the L?ven criterion of crystallization to the case of melting. This localization criterion is found to be applicable for both normally melting substances and substances that melt with a decrease in the specific volume...
Odor purification process using bio-function, which is technologically called bio-deodorizing process, utilizes the function of microorganism to convert mal-odor substances to non-odor substances. It attracts attention because the operation cost of a facility is low due to non-use of chemicals and energy, and because it is environmentally friendly without the possibility of generating secondary pollution. It is being used in deodorizing at sewage treatment facilities, fertilizer plants, coating plants, and foundries in Japan, and is more widely used in Europe. The conventional deodorizing technology in Japan mostly focuses on processes of physical chemistry such as activated carbon treatment, chemical scrubbing, combustion, and masking, but bio-deodorizing process tends to replace the conventional processes. This paper explains (1) relation of mal-odor and microorganism, (2) bio-deodorizing system (solid phase system and liquid phase system), ...
Purpose: To enable the solidification of liquid waste containing radioactive substance in a free shape with large volume reduction ratio without a pulverizing step by producing solute in the liquid waste as a slurry in a predetermined organic solvent and forming it into a cake by mechanical exfoliation. Method: Liquid waste containing suitably concentrated radioactive substances is supplied to a centrifugal thin film evaporator together with an organic agent having a higher boiling point than water and a non aqueous solution to evaporate the water content, the solute in the waste is produced as a slurry in the organic solvent, and removed as cake-state solute slightly residued with the organic solvent by the mechanical exfoliation such as centrifugal exfoliation or settling exfoliation from the slurry-state liquid. Accordingly, it can be increased in size as compared with the powder reduced in volume of the radioactive liquid waste, and can be ...
Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas quantities. Specific tests were conducted to determine permeability parameters of a variety of membrane materials with reference to radon flow capabilities. Tests were conducted both within laboratory and in-situ emanation environments where concentrations and diffusion flows of radon gas were known to exist. Equilibrium radon gas concentrations were monitored in initially radon-free chambers adjacent to gas sources, but separated by specified membrane substances. Membrane barrier effectiveness was demonstrated to result in reduced emanation concentrations of radon gas within the sampling chamber atmosphere. Minimum gas concentrations were evidenced where the barrier membrane material was shown to exhibit lowest radon permeability characteristics.
Some N-containing or S-containing organic substances and some acetylenic alcohols were tested as inhibitors of the corrosive attack suffered by Fe-based metallic glasses in deaerated 0.1 N sulfuric acid (H{sub 2}SO{sub 4}) solution at 25 C. It was verified that the specific action these compounds exerted on the corrosion process of the amorphous alloys was similar to the one these compounds exerted on polycrystalline iron. The most efficient substances were those containing a sulfur atom with available lone pairs, which chiefly inhibited the anodic reaction of both metal specimens. Owing to the chemical and physical homogeneity of the amorphous alloy, the chemisorbed inhibitor film that formed on the glassy surface was more stable and protective than that formed on the polycrystalline iron.
New non-stationary non-contracted form of the erosive radially-slotted discharge as a thin round sheet with the current of the azimuth direction have been discovered, its existence beings stipulated by a radial transport-wave fluxes. Characteristic features of this discharge is self-confinement of the discharge current magnitude, corresponding decrease of the current pulse duration and occurrence of an energy and substance ejection with rather unusual properties. Measurements of kinetics of the discharge current, the plasma radiation intensity and an electrical probe signal, as well as the transmission electron microscope investigations of characteristic aerodisperse aggregates arising the erosive phase, have been carried out. The probe signal duration was about 10 times greater than that of the current; its kinetics was complicated suggesting existence in the slot of two components with fundamentally different properties and states of the ...
The concept of antimicrobial packaging has received great attention because of its potential to enhance food safety. Several studies have explored its applications and effectiveness to suppress pathogenic microorganisms. However, few studies have analyzed the alterations caused in the engineering properties of food-packaging polymers after the incorporation of antimicrobials. Such information is very important to understand the feasibility of producing antimicrobial packaging films on the industrial scale. This review explores the work done so far to evaluate how the incorporation of antimicrobial substances affects the properties of food-packaging systems. This article also emphasizes diffusion studies on antimicrobial substances through packaging films and the analytical solutions used t...
The hepatic removal of albumin-bound substances from plasma requires that they dissociate from albumin. Using indirect methods, we and others have proposed that dissociation may be catalyzed by interaction...Full Text Available
By the example of CH2Cl2, CF2Cl2, CHF2Cl, C2F6, C2H6, SF6 and C6H12 we have investigated the isobaric thermal conductivity jump at crystal-liquid phase transition. It is shown that the reduction in the thermal conductivity at melting derives from the degree of orientational ordering of the crystals at pre-melting point.
Brain scintiscanning which was first carried out exclusively 'statical' and only with test substances of limited quality has been replaced nowadays by 'dynamical' camera-sequency-scintiscanning with technetium. This brought considerable progress not only for identifying but also for the differential diagnosis of cerebro-organic processes. Development, methods, and integration of brain scintiscanning in a diagnostical conception are described briefly. (orig.).
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and dioxin-like compounds are widely encountered toxic substances suspected of interfering with the endocrine systems of humans and wildlife,...Full Text Available
Abstract Clonidine Extended Release Augmentation of Psychostimulants in ADHD ADHD a Risk Factor for Substance Abuse; Cognitive Deficits Not a Predictor Commentary on Kollins et al.; Clonidine XR Augmentation for ADHD Pharmacologic Treatment of Childhood Insomnias Effects of Guanfacine Extended Release on Alertness in ADHD Long Term ADHD Drug Treatment Bipolar Disorder Rates Similar Across Selected Countries Group CBT Alone or Group CBT Plus SSRIs in Childhood Anxiety Resolution of Quetiapine-Induced Oral Dyskinesia From the FDA
Our work is towards mechanistically understanding interactions of unsaturated bacterial biofilms and their extracellular polymeric substances (EPS) with actinide metals and metal surrogates under vadose zone conditions. Because metal contaminants in the vadose zone co-occur with organic pollutants, some of our work has included experiments with organic pollutants.
This request is submitted to seek interim approval to operate a Toxic Substances Control Act (TSCA) of 1976 chemical waste landfill for the disposal of polychlorinated biphenyl (PCB) waste. Operation of a chemical waste landfill for disposal of PCB waste ...
The rate of appearance of labeled thyroxine (T4) and albumin in lymph from various areas after simultaneous i.v. injection of the labeled substances in conscious ambulatory sheep has been used to estimate...Full Text Available
As a result of the accident at the Chernobyl Power Plant the larger part of Belarus turned out to be polluted by radionuclides. At present isotopes of Cs, Sr and Pu, characterized by long half-lives are most dangerous for the health of the population of the polluted territories. The aim of the present work was to characterize plant species with high "1"3"7Cs and "9"0Sr accumulation ability and to determine the dependence of the accumulation on the treatment with biologically active substances. (author)
Substances which exercise a pulmonary toxic action will first of all produce alveolar and perivascular oedemas followed by fibrosis. Differential diagnosis is explained on the basis of two cases of a fatal mitomycin fibrosis of the lung, as well as the observation of fibrous changes following the administration of Bleomycin and Metothrexat. The course of pulmonary fibroses caused by paraquat is described for two cases of fatal paraquat intoxications. (orig.).
Governments around the world will soon make decisions on policies that could determine the fate of the ozone layer-the Earth's shield from harmful ultraviolet radiation. The Vienna Convention for the Protection of the Ozone Layer, signed on March 22, 1985, created a framework for scientific cooperation and information exchange that will form the basis for a protocol for controlling substances thought to threaten the ozone layer. As of mid-1987, 29 countries had signed the Convention, including the major producers and users of chlorofluorocarbons (CFCs), the most important of suspect chemicals.
Caffeine and related xanthines were identified as potent stimulators for the bacterial cellulose production in A. xylinum. These compounds are present in several plants whose infusions are useful as culture-medium supplements for this acetobacterium. The proposed target for these native purine-like inhibitory substances is the novel diguanyl nucleotide phosphodiesterase(s) that participates in the bacterial cellulogenic complex.
The use of filters of activated-charcoal particles in drinking-water purification plants assists in the elimination of organic micropollutant substances. The authors report on a study which sought to investigate the mechanism of organic matter; they describe the experimental programme, which used different size ranges of mineral-based activated charcoal, present the experimental findings and discuss the results. 16 references.
In response to severe maintenance problems caused by the highly corrosive toxic and radioactive substance used in the nuclear reprocessing industry, AEA Technology (formerly the United Kingdom Atomic Energy Authority) has developed a series of power fluidics devices with no moving parts. These maintenance-free devices are described in this article which also explores applications in fields outside their original brief. (UK).
Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The ...
The endogenous levels of several plant growth substances (indole acetic acid, IAA; abscisic acid, ABA; zeatin, Z; zeatin riboside, [9R]Z; isopentenyladenine, iP; and isopentenyladenosine, [9R]iP were...Full Text Available
Exogenous [14C]indole-3-acetic acid (IAA) is conjugated in citrus (Citrus sinensis) leaf tissues to one major substance which has been identified as indole-3-acetylaspartic...Full Text Available
Research programs from the following sections and programs are summarized: aquatic ecology, environmental resources, earth sciences, terrestrial ecology, advanced fossil energy program, toxic substances program, environmental impacts program, biomass, low-level waste research and development program, US DOE low-level waste management program, and waste isolation program.
This paper reviews emission standards, technologies to control emissions, and the cost of these controls. It is concluded that international bodies will increasingly set minimum emissions, these standards will continue to be reduced, and in addition new substances will be controlled. The cost of this control will likely not exceed 0.5 cents per kWe-hr. 4 refs., 3 tabs.
The past three years of work for the Air Force Office of Scientific Research has resulted in the development of a congenic mouse model of JP-8 jet fuel exposure, the role of substance P in the JP-8 jet fuel-induced lung injury process, and development of ...
Cesium and selenium intake of cultivated mushrooms (Agaricus bisporus), with these elements previously added to culture medium, has been examined from the viewpoint of health- and environmental protection. The process of measuring has been carried out by the radionuclide X-ray fluorescence technique. Treatments of the elementary substance with Se salt appears to influence the Se content of the mushrooms to a significant extent. Cs intake is of considerable importance, as this element is accumulated by mushrooms. (author)
In this lesson you will learn about density and why some things float and others sink. Imagine you and a friend are on a camping trip. As you walk along a stream, your friend notices some shiny gold rocks. You pick them up wondering if they are real gold nuggets. Your friend remembers there is a mineral that looks like gold, "fools gold", or pyrite. The density of ...
The decree refers to conditions of irradiation of food and its components for radappertization and radurization using gamma radiation from cobalt 60 or cesium 137, X radiation or electron beam up to maximum total medium absorbed dose 10 kGy.
The invention concerns a container for the long term storage of irradiated nuclear reactor fuel elements, which consists mainly of a basic body, at least one lid and an outside ring shaped lid tightening device, which acts on the basic body and the lid and holds the contact surface of the lid tight against the contact surface of the basic body, where the basic body, lid and the lid tightening device consist of corrosion-proof materials. (orig./HP).
Biosorption means the storage of substances at the cell envelope. Different microbial biomasses were tested for the separation of radionuclides from mining waters. Results of a pilot plant demonstrate the ability of these techniques for water cleaning processes. An effluent concentration of lower than 1 mg/l (in most cases 0.1 mg/1) could be realized in a pilot plant by using pure cells of a methylotrophic strain of bacteria as well as using of a fungal mycelia.
Single-electrode transient behavior was measured mainly during the discharging process for a model cell of electric double layer capacitor with nano-porous carbon electrodes and reference electrode. Apparent conductivity in the cell, which we call `effective conductivity,` is determined with approximation of current in transient behavior to a one-dimensional electrophoretic model. A comparison of effective conductivity with conductivity of bulk solution suggests an interesting mechanism of transfer of electrolyte ions. The difference in transient behavior between various electrolyte ions was not conspicuous in spite of distinctive differences in conductivity of each bulk solution. The large pore diameter of the carbon electrode results in rapid transient behavior and such an electrode should be suitable for rapid charge and discharge. The effect of origin of carbon electrode is found to be significant to bring considerable differences in ...
The electricity industry in the US today is at a crossroads. The restructuring debate going on in most regions has made it clear that the traditional model of vertically integrated firms serving defined franchise areas and regulated by state commissions may not be the pattern for the future. The demands of large customers seeking direct access to power markets, the entry of new participants, and proposed reforms of the regulatory process all signify a momentum for fundamental change in the organization of the industry. This paper addresses electricity restructuring from the perspective of bulk power markets. The authors focus attention on the organization of electricity trade and the various ways it has been and might be conducted. Their approach concentrates on conceptual models and empirical case studies, not on specific proposals made by particular utilities or commissions. They review literature in economics and power system engineering that is relevant to the ...
In the recent work [Proc. of SPIE 7801, 7801-2/1-12 (2010), Opt. Eng. 50(5) (2011), in press], we have reported on improvement of the Developmental Long Trace Profiler (DLTP), a slope measuring profiler available at the Advanced Light Source Optical Metrology Laboratory, achieved by replacing the bulk pentaprism with a mirror based pentaprism (MBPP). An original experimental procedure for optimal mutual alignment of the MBPP mirrors has been suggested and verified with numerical ray tracing simulations. It has been experimentally shown that the optimally aligned MBPP allows the elimination of systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of the bulk pentaprism. In the present article, we provide the analytical derivation and verification of easily executed optimal alignment algorithms for two different designs of mirror based pentaprisms. We also provide an analytical description for the ...
Reactor Regulating System (RRS) of TAPP-3 and 4 (540 MWe PHWR) addresses issues of elaborate Flux Tilt Control as applied to large Reactor Cores in addition to the traditional Bulk Power (Actual Power) Control. The control of Bulk and Zonal Power by RRS through the use of Zonal Control Compartments (ZCCs) has been successfully demonstrated in the Indian PHWRs for the first time. Features like automation in Demand Power Maneuvering, Manual Movement of Reactivity Devices through the Human Machine Interface (HMI) and the supervised withdrawal of Shut-off Rods during Auto Criticality are also included. Special algorithms to measure and control the individual Zone Power and Bulk Power also form part of RRS algorithms. This paper describes the salient features of RRS of TAPP-3 and 4 and the improvement carried out based on the feedback of past 1 year of operation of TAPP-4 at around 90 % FP. (author)
Local-density-functional calculations of the energy bands, equilibrium lattice constant, bulk modulus, and cohesive energy have been performed using a newly developed self-consistent full-potential linearized augmented-plane-wave (LAPW) program. Scalar-relativistic effects are included for the band states, and the core-level states are treated fully relativistically in a central-field approximation. Excellent agreement is obtained with the experimental lattice constant and bulk modulus. Generally good agreement is obtained with the scalar-relativistic pseudopotential results of Bylander and Kleinman. In this context, the impact of various approximations used in including the core states is assessed, and these findings are related to the frozen-core and pseudopotential approximations, especially with regard to the treatment of the somewhat overlapping 5p semicore states and their effect on ground-state properties. Comparison with the recent LAPW ...
A scalar-relativistic procedure for calculating the valence-electron contribution to the total energy of bulk and thin-film solids has been developed and applied to the fcc and bcc phases of the group-VIB transition elements Cr, Mo, and W. This approach, which is based on the linear augmented-plane-wave method and local-density-functional theory, contains no shape approximations for either the charge density or potential. The formulation adopts a rigid-core approximation and incorporates an exact treatment of the core-charge tails that extend beyond the muffin-tin spheres. The application of this procedure to bcc Cr, Mo, and W yields calculated lattice parameters and bulk moduli that are in good (Cr) to excellent (Mo and W) agreement with experiment. The present calculated properties also agree quite well with the results of previous calculations involving a variety of band-structure methods. The calculated fcc-bcc energy difference for Cr, Mo, ...
ObjectivesThe aim of this study was to evaluate the relationship between micro-tensile bond strength (mTBS) and ultimate tensile strength (UTS) of resin composite restorations in cavities filled by a bulk or incremental technique using the micro-tensile test.MethodsClass I cavities (4mm long, 3mm wide, 3mm deep) were prepared into dentine of sixteen human molars. All cavities were bonded with Clearfil SE Bond and restored with AP-X composite with either a bulk or incremental technique. After storage in water for 24h, the teeth were vertically sectioned to yield two slabs. Each slab was sectioned into three sticks. Sticks of one slab were trimmed into an hourglass of 0.7mm2 area at resin-dentine interface for bond strength measurement while the other sticks were trimmed at the centre of the...
Platinum Group Element (PGE) concentrations in garnet pyroxenite xenoliths from Oahu, Hawaii, are significantly lower than those in mantle peridotites and show fractionated patterns (e.g. PdN/OsN=2-10, PdN/IrN=4-24; N=chondrite normalized) and very high ReN/OsN ratios (9-248). Mass balance calculations show that the bulk rock pyroxenite PGE inventory is controlled by the presence of sulfide phases. The 187Os/188Os ratios of these pyroxenites vary from subchondritic to suprachondritic (0.123-0.164); and the 187Os/188Os ratios show good correlations with bulk rock and clinopyroxene major and trace element compositions, and bulk rock PGE and sulfur abundances. These observations suggest that the Os isotope compositions in these pyroxenites largely reflect primary processes in the oceanic mant...
The purpose of the trip was to visit Nobel Chemicals in Sweden and to confer with the Department of Transportation personnel in Sweden and in England on the technical and regulatory problems in the bulk shipping of the high explosives RDX and HMX. It is customary in the United States (US) to add isopropyl alcohol to the bulk shipment of water-wet high explosives RDX and HMX. The explosives are packed in cloth bags which are placed in plastic-lined fiber drums. The addition of alcohol presumably prevents mildewing of cloth bags and freezing of the wet explosives in cold weather. In Europe, however, these explosives are shipped in polyethylene-lined fiber drums with not less than 15% water only, even in cold weather. Water-wet frozen explosives have not proved to be any more sensitive than its unfrozen counterpart and no mildew problem has been encountered. It looks promising that the US Department of Transportation regulations can be changed to ...
Monopolar charge disorder effects are studied in the context of fluctuation-induced interactions between neutral dielectric slabs. It is shown that quenched bulk charge disorder gives rise to an additive contribution to the net interaction force which decays as the inverse distance between dielectric surfaces. This effect may thus completely mask the standard Casimir--van der Waals effect. By contrast, annealed (bulk or surface) charge disorder leads to a net interaction force whose large-distance behavior coincides with the universal Casimir force between perfect conductors, which scales as inverse cubic distance, and the dielectric properties enter only in subleading corrections.
A self-consistent pseudopotential method together with a mixed-basis set of plane waves and Gaussian orbitals are used to determine the electronic structure of the (001) surface of molybdenum. The pseudopotential is derived from a self-consistent calculation of the atomic levels and wave functions, and is tested for bulk molybdenum. The resulting bulk band structure and density of states are compared with existing augmented-plane-wave APW calculations. The same potential is applied to investigate the electronic structure of an uncontracted Mo (001) surface. A complete analysis of the surface states is given in terms of their distribution in the two-dimensional surface Brillouin zone, charge-density distribution, and the local density of states. The results are in very good agreement with recent photoemission measurements.
Intrusive degassing and recycling of degassed and dense magma at depth have been proposed for a long time at Stromboli. The brief explosive event that occurred at the summit craters on 9 January 2005 threw out bombs and lapilli that could be good candidates to illustrate recycling of shallow degassed magma at depth. We present an extensive data set on both the textures and the mineral, bulk rock and glassy matrix chemistry of the ?9 Jan? products. The latter have the common shoshonitic?basaltic bulk composition of lavas and scoriae issued from typical strombolian activity. In contrast they differ by the heterogeneous chemistry of their matrix glasses and their crystal textures that testify to crystal dissolution event(s) just prior magma crystallization upon ascent and eruption. Comparison...
This paper is devoted to the coordination of secondary voltage control and adaptive parameters resetting of the power system stabilizer, in order to increase stability, margins in real time operation. Secondary voltage control and the power system stabilizer are two control loops, which affect the same system parameter on different bases - that parameter is the voltage set-point of the automatic voltage regulator. It was found that their effects were complementary. In that way, through the proper coordination of actions of these two control loops open up a wide range of possibilities for ensuring the stability of bulk power systems in real time. For the establishment of this coordination, an on-line sequential algorithm is proposed which is based on adaptive resetting of the voltage set-point of the automatic voltage regulator and the PSS parameters. The efficiency of the proposed algorithm is confined through simulations on a real-life multi-machine ...
Magnetic structures and magnetocrystalline anisotropy (MCA) of tetragonal phase Fe_3Pt with an L1_2 atomic ordering in bulk and thin film are investigated by means of the first-principles full-potential linearized augmented plane-wave method. The results obtained predict that the tetragonal phase, in which the tetragonal distortion with (c/a) = 0.95 makes an asymmetry of magnetic properties along the c-axis (out-of-plane) and a-axis (in-plane), has an out-of-plane MCA. In addition, from the thin film calculations, the presence of surface is found to strongly enhance the out-of-plane MCA.
A polarized neutron reflectometry study of the magnetization density depth profile of a Co{sub 0.1}Pt{sub 0.9}-CoPt{sub 3} bilayer film found evidence for an induced moment in the Co{sub 0.1}Pt{sup 0.9} overlayer in close proximity to the CoPt{sub 3} underlayer. If the moment of Co in these films is that of the bulk, then the {mu}{sub Pt} = 0.09(1){mu}{sub B} in the overlayer, and {mu}{sub Pt} = 0.04(1){mu}{sub B} in the underlayer. In addition, ferromagnetic order of the Co{sub 0.1}Pt{sub 0.9} overlayer was observed 8K above {Tc} for the material in the bulk.
In a method for formulating a multi-component explosive composition, the steps are described comprising: (a) providing a defined body of unconsolidated particulate aluminum fuel granules having an average particle size within the range of 1/64-1/4 inch and an average bulk density within the range of 0.2-1.0 gm/cc; (b) providing a phase oxidizing liquid; and (c) flooding said body of particulate aluminum fuel of step (a) with the oxidizing liquid of step (b) to provide a bulk density of said mixture of oxidizing liquid and particulate aluminum fuel mass within the range of 1.2-1.7 gm/cc and provide an explosive formulation detonable at 20 C in a diameter of 4 inches by a one pound pentolite booster.
Deformations of topological open string theories are described, with an emphasis on their algebraic structure. They are encoded in the mixed bulk-boundary correlators. They constitute the Hochschild complex of the open string algebra - the complex of multilinear maps on the boundary Hilbert space. This complex is known to have the structure of a Gerstenhaber algebra (Deligne theorem), which is also found in closed string theory. Generalising the case of function algebras with a B-field, we identify the algebraic operations of the bulk sector, in terms of the mixed correlators. This gives a physical realisation of the Deligne theorem. We translate to the language of certain operads (spaces of d-discs with gluing) and d-algebras, and comment on generalisations, notably to the AdS/CFT correspondence. The formalism is applied to the topological A- and B-models on the disc. (author)
Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.
In Randall-Sundrum-type brane-world cosmologies, the dynamical equations on the three-brane differ from the general relativity equations by terms that carry the effects of imbedding and of the free gravitational field in the five-dimensional bulk. Instead of starting from an ansatz for the metric, we derive the covariant nonlinear dynamical equations for the gravitational and matter fields on the brane. The local energy-momentum corrections are significant only at very high energies, and in this regime we show that fluid world-lines have a non-gravitational acceleration off the brane. The imprint on the brane of the nonlocal gravitational field in the bulk is more subtle, and we provide a careful decomposition of this effect. The nonlocal energy density determines the tidal acceleration in the off-brane direction, and can oppose singularity formation via the generalized Raychaudhuri equation. Unlike the nonlocal energy density and flux, the ...
The optical birefringence of rod-like nematogens (7CB, 8CB), imbibed in parallel silica channels with 10 nm diameter and 300 micrometer length, is measured and compared to the thermotropic bulk behavior. The orientational order of the confined liquid crystals, quantified by the uniaxial nematic ordering parameter, evolves continuously between paranematic and nematic states, in contrast to the discontinuous isotropic-to-nematic bulk phase transitions. A Landau-de Gennes model reveals that the strength of the orientational ordering fields, imposed by the silica walls, is beyond a critical threshold, that separates discontinuous from continuous paranematic-to-nematic behavior. Quenched disorder effects, attributable to wall irregularities, leave the transition temperatures affected only marginally, despite the strong ordering fields in the channels.
We conjecture that the end point of bulk closed string tachyon decay at any nonzero coupling is the annihilation of space-time by Witten's bubble of nothing, resulting in a topological phase of the theory. In support of this we present a variety of situations in which there is a correspondence between the existence of perturbative tachyons in one regime and the semiclassical annihilation of space-time. Our discussion will include many recently investigated scenarios in string theory including Scherk-Schwarz compactifications, Melvin magnetic backgrounds, and noncompact orbifolds. We use this conjecture to investigate a possible web of dualities relating the eleven-dimensional Fabinger-Horava background with nonsupersymmetric string theories. Along the way we point out where our conjecture resolves some of the puzzles associated with bulk closed string tachyon condensation.
The CERL Code was developed to describe the solution chemistry of the water on the steam generating side of PWR reactors. It is designed to calculate the equilibrium species distribution resulting from the interaction of impurities, corrosion products, and additives in the aqueous solution. It calculates the extent of ion-ion interactions, the precipitation of insoluble species and the amount of solute that partitions into the vapor phase when some of the water evaporates. This knowledge of the bulk phase equilibrium distribution of species, especially the pH should be useful in describing the corrosion processes at the solid liquid boundary. The code does not calculate any changes in oxidation states or any rates of reaction. Therefore, it is incapable of calculating the actual corrosion rates. It is anticipated that it will be used as a subprogram of a larger program that will include the redox reactions and the rates of the reactions. The purpose of the code at ...
The performance of a gas-fuelled diesel engine (dual fuel) is examined at light load and an effective threshold limit to the combustion of the gaseous fuel through bulk flame spread is identified. The relationship of such a limit to some of the key operating parameters is then discussed. A comparison between the measured values of the limit with those corresponding to the lower flammability limits of the gaseous fuel when evaluated under the prevailing cylinder conditions during pilot diesel fuel ignition showed similar trends. It is suggested that such a similarity may form a basis for estimating the lean operation limits for duel a fuel combustion in engines. A simple approach for estimating the limiting equivalence ratio for the apparent bulk flame spread limit is described for a methane-fuelled dual fuel engine. (Author)
Lectin is a generic name of sugar binding protein in living organisms. With an objective to clarify physiological functions of lectin in marine invertebrates and utilize it as a useful material in the bio-chemical industry, studies were carried out on the chemical structure, distribution in living organisms and structural changes of lectin. Lectin is involved with such physiological actions as immunity reactions, generation and differentiation, Ca fixation and symbiosis. Lectin is one of the main components of lymph fluid in shellfish and crustacean, and is a multi-functional polymer that is related with foreign substance recognition, Ca transport, and shell formation. Lectin of a certain kind shows strong actions to accelerate cell division. Organs and cells were cultivated for lectin producing organs and lectin producing cells to verify the production thereof. Elucidation was attempted in a molecular level on such physiological functions as foreign ...
Under Section 5 of the Toxic Substances Control Act (TSCA), manufacturers must notify the US Environmental Protection Agency (EPA) 90 days before manufacturing, processing, or importing a new chemical substance. This is referred to as a premanufacture notice (PMN). The PMN must contain certain information including chemical identity, production volume, proposed uses, estimates of exposure and release, and any health or environmental test data that are available to the submitter. Because there is no explicit statutory authority that requires testing of new chemicals prior to their entry into the market, most PMNs are submitted with little or no data. As a result, EPA has developed special techniques for hazard assessment of PMN chemicals. These include (1) evaluation of available data on the chemical itself, (2) evaluation of data on analogues of the PMN, or evaluation of data on metabolites or analogues of metabolites of the PMN, (3) use of ...
Investigations were made on the biodegradability and bacterial toxicity of chemicals. The intention was to obtain data necessary for estimating and judging the behaviour of these chemicals during aerobic biological waste water treatment. The course of biodegradation and toxicity with time and concentration could be measured, quantified and described. As test procedure, the respirometric dilution method was used. This method is based on a die away test with continuous measuring of the oxygen used for biochemical oxidation processes. The course of the oxygen demand with time and concentration shows the biodegradation and toxicity patterns of the tested chemical. A variety of household and industrial chemicals were investigated. One group of substances were microbiocides, some of which showed toxic effects at concentrations less than 20 mg/l while others were biodegradable even at concentrations of 200 mg/l. Another group of test chemicals were anionic and nonionic ...
The ROTAMIX process for the treatment of contaminated soils, developed by GSI Environment of Sherbrooke, Quebec, is described. The technology combines the use of a self-propelled rotary turner with bioactivating nutrients and structuring agents. Results of various trials using this process showed that soils contaminated with pentachlorophenol and heavy petroleum hydrocarbons, substances that do not easily break down, were decontaminated to a level that corresponds to the C criterion of the Quebec Ministry of the Environment. The ROTAMIX process was found to improve solid/liquid/gas exchanges, and increased water retention capacity of the treated soil. The technology is not constrained by the fine particle concentration that may result from the addition of structuring agents. It produces no leachate water or gaseous emissions. It broadens the range of contaminants that can be treated, including contaminants that resist biodegradation. The process is relatively cheap ...
This paper describes inorganic solid electrolytes from a viewpoint of electrolytes for lithium batteries. Lithium ion conductive inorganic solid electrolytes are largely divided into crystalline and amorphous substances. Crystalline substances are known as LiI and Li3N, and also oxygen acid salt. However, when considering application to a battery, its large grain boundary resistance and electrochemical instability would be a problem. Lithium ion conductive amorphous solid electrolytes are divided into an oxide system and a sulfide system. Since most of them do not contain transition metal elements, they are stable against electrochemical reduction, and ions move isotropically in electrolyte. Therefore, ion conduction paths across the grain boundaries may be connected more easily, forming an electrolyte with low grain boundary resistance. As a result of the efforts of the authors in searching new additives substituting LiI, it was found that ...
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 sample preparation 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 laser-ICP were 10-fold lower than by use of a nebulizer. (orig.).
This report presents the results of the preliminary assessment (PA) conducted by Argonne National Laboratory at the Georgia Army National Guard (GAARNG) facility near Hinesville, Georgia, known as the National Guard Training Center (NGTC). Preliminary assessments of federal facilities are being conducted to compile the information necessary for completing preremedial activities and to provide a priority basis for completing corrective actions (where necessary) in response to releases of hazardous substances. The principal objective of the PA is to characterize the site accurately and determine the need for further action by examining previous site activities, types and quantities of hazardous substances utilized, and potential pathways by which contamination could affect public health and the environment. The scope of this assessment is limited to the facilities and past activities contained within the NGTC. Preliminary assessment site score ...
Erectile dysfunction following radical prostatectomy remains a frequent problem despite the development of nerve-sparing techniques. This erectile dysfunction is believed to be neurogenic, enhanced by hypoxia-induced structural changes which result in additional veno-occlusive dysfunction. Recently, daily use of intracavernous vasoactive substances and oral use of PDE5-inhibitors have been clinically studied for treatment of postprostatectomy erectile dysfunction. Since these studies showed benefits of "penile rehabilitation therapy," these effects have been studied in a preclinical setting. We reviewed experimental literature on erectile tissue preserving and neuroregenerative treatment strategies, and found that preservation of the erectile tissue by the use of intracavernous nitric oxide donors or vasoactive substances, oral PDE5-inhibitors, and hyperbaric oxygen therapy improved erectile function by antifibrotic effects and preservation of ...
Mechanisms that govern transport, accumulation and toxicity of persistent pollutants at interfaces in aquatic ecosystems were the foci of this thesis. Specific attention was paid to humic substances, their occurrence, composition, and role in exchange processes across interfaces. It was concluded that: The composition of humic substances in aquatic surface microlayers is different from that of the subsurface water and terrestrial humic matter. Levels of dissolved organic carbon (DOC) in the aquatic surface microlayer reflect the DOC levels in the subsurface water. While the levels and enrichment of DOC in the microlayer generally show small variations, the levels and enrichment of particulate organic carbon (POC) vary to a great extent. Similarities exist between aquatic surface films, artificial semi-permeable and biological membranes regarding their structure and functioning. Acidification and liming of freshwater ecosystems affect DOC:POC ...
The focus of the present Great Lakes water quality agreement between Canada and the United States is on transboundary pollution and particularly the injury to health and property from exposures to persistent toxic substances. Several scientists and policy advisors have suggested, on the basis of the Ecosystem Approach and systems theory, that the agenda should move on to other demanding topics, such as the introduction of exotic species, biodiversity, habitat restoration, fisheries management, sustainable development, and governance of the Great Lakes basin. None of these issues, however, poses the same scale of threat to national sovereignty and bilateral interests as does transboundary pollution. Thus, none warrants the degree of attention that has been and should be paid, despite declining budgets, to assessing and controlling releases of persistent toxic substances that continue to injure fish, wildlife, and human health. Instead, it is ...
Accelerated oxidation treatment technology is introduced for use in the treatment of poor quality water by ozone injected from the bottom of a pressurized ozone contact tank. Under study as oxidation accelerating processes using ozone center about an ozone/hydrogen peroxide treatment, ozone/UV treatment, ozone/hydrogen peroxide/UV treatment, etc. As the result of testing, important respects in accelerated oxidation are learned, which are stated below. In the ozone-aided treatment, there are some substances, such as chromatic matters, that can be removed more rapidly when in direct contact with gaseous ozone. In this case, the concentration of remnant ozone poses an important problem. In relation to the amount of injected hydrogen peroxide, what is important is the ozone/hydrogen peroxide injection ratio relative to the substance that is to be removed. In the use of UV rays, since the decomposition rate of dissolved ozone is approximately ten ...
The chemist and pharmacologist Fritz Hauschild developed the sympathomimetic agent Pervitin (metamphetamin) in the 1930s. Not only because of the abuse of the stimulant during the Second World War ("pilot's chocolate") it is one of the most controversial substances in drug history. Nearly forgotten are Hauschild's contributions to build up the drug system in the GDR. Although he was a convinced communist, the skilful pharmacologist gave very early warning of the imminent lack of innovation in the GDR pharmaceutical industry. A letter which he addressed to the Minister of Health, Max Sefrin (born 1913), did not lack explicitness. PMID:15997840
The purpose of this study is to extend the knowledge base for wetland treatment to include processes and substances of particular importance to small, on-site systems receiving oil and gas well waste water. Collection of data on the sorption of heavy metals and the degradation of toxic organics is one of the key tasks. The toxic organics phenolics and anthracene, and chromium and copper have been selected as target adsorbates. An information search was performed on oil refinery waste treatment wetland systems.
In the Institute of Nuclear Chemistry and Technology research on microbiological decontamination of medicinal herbs by irradiation has been carried out since 1996. It was shown that using ionizing radiation (a dose of 10 kGy) can obtain satisfactory results of microbiological decontamination of these products. The content of essential biologically active substances such as essential oils, flavonoids, glycosides, anthocyans, antra-compounds, poliphenoloacids, triterpene saponins, oleanosides and plants mucus did not change significantly after irradiation. Pharmacological activity of medicinal herbs has been found satisfactory after microbiological decontamination by irradiation.
Some aspects of metrological provision of X-ray radiometric analyzers for mineral raw composition and gamma-gamma-logging equipment are considered. Standard samples (SS) based on the phenol-formaldehyde resin with the introduced quantities calculated of element compositions in the form of oxides and salts are described. Principles of metrological provision developed are used when carrying out state acceptance tests of X-ray radiometric analyzer RAL-M-102 ''Ehkran'' and gamma-gamma-logging equipmnt RSK-102. Economic benefit from introduction of an SS set is #approx# 60-100 thousand roubles per year.
A study was undertaken of problems encountered in the use of thermal power station coal ash and red mud (an aluminium smelting residue) as a banking or filling material, the aim being the effective utilization of these substances. Like clinker, coal ash and red mud can also be used as improvers, but there are various problems such as absorption swelling, strong alkalinity, and the difficulty of controlling the moisture content. Certain measures have to be carried out in on-site use to combat these problems. (11 refs.)
A conceptual framework is proposed within which the notion of risk as normally used in risk assessment (RA) could be enlarged in line with the real substance of social issues of technology policy, to help avoid RA's threatened irrelevance to social decision making. It is argued that the frequent organizational incoherence and thus the unviability of modern technology arises from 'social alienation' between the innovation-commitment phase and the implementation of the technology in society. The roles of technical elites and of particular concepts of technology in this alienation are emphasized. One of the case studies deals with 'Nuclear power - myths of scientific and organizational realism' and discusses the UK nuclear 'programme' and the Three Mile Island accident. (author).
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The investigation of the petroleum contamination in marine organisms requires the trace level quantitative determination of indicative substances to be identified by a fingerprint of petroleum. Polymethylnaphthalene (PMN) and polymethylphenanthrene (PMP) were chosen because of their simple separation from a crude oil by means of an activated charcoal chromatography, their relatively high existence in aromatic compounds, and their persistence relative to other petroleum components in the tissue of oil contaminated marine organisms. The purpose of this paper is to present an activated charcoal chromatographic separation procedure of PMN and PMP in a crude oil and a trace level quantitative analytical method of them in marine organisms by mass fragmentography (MF).
Direct electric heating by passing an electrical current directly through a bed of adsorbent may prove to be an efficient means of regenerating activated charcoal in continuous and batch adsorption processes. Obvious advantages of this type of regeneration are its almost complete lack of inertia, which makes it possible to reduce the number and dimensions of the adsorbers, and its highly efficient use of energy due to the small number of steps in the conversion of the energy, as well as the reduction of heat losses involved in warming the structure and making up for losses to the surroundings. The authors consider the kinetics of direct electric heating of a stationary bed of activated charcoal not containing adsorbed substances.
ObjectivesNot EnteredDescriptionMethane hydrate in an ice-like substance consisting of molecules of methane gas combined chemically with water. It is stable at high pressures and low temperatures. Since the ocean floor is normally cold, but temperatures increase with depth inside the Earth, such conditions normally prevail for a few hundred meters below the seafloor where the ocean depth is more than a few hundred metres. Methane beneath the ocean floor is formed by the decomposition of organic material. At the edges of the co [continued...
Hexane extract of licorice (Glycyrrhiza glabra L.) roots was obtained and investigated. Hydrocarbons, sterol ethers, triacylglycerides, free fatty acids, and free sterols were identified. The extract contains 70% neutral and 30% polar lipids. It is established that the lipid fraction of licorice roots is more effective than the analogous fraction of rosehip oil in stimulating the reparative regeneration of skin. In addition, this fraction also exhibits pronounced antiinflammatory and antiulcer effects, while being virtually nontoxic. Based on these results, the lipid fraction of licorice roots can be recommended as a parent substance for creating effective preparations in various medicinal forms.
The formation of the ions charge and energy distributions of the ions slowed down or randomly changing their charge in the collisions with the medium particles are studied. The effect of the ions dispersion by the charge on the Bragg curve form is investigated. The proposed diffusion approximation for the heavy ions kinetic equation makes it possible to determine simply the parameters of the ions distribution by charge and energy on the whole way of the ions motion. The relation between the ions charge distribution characteristics and the cross sections of the ionization-recombination processes is indicated. The ions distributions, calculated in the proposed analytical model, are compared with the results of the numerical calculations. Good agreement between the analytical, numerical and experimental results is obtained
A calculation method of the X-ray radiation dose (energy of gamma- radiation remains in the range of energies where the mechanism of photoelectric absorption is the prevailing one) absorbed in the absorbers of final thickness is suggested. Calculations of resorption of secondary radiation (characteristic fluorescences) in the substance and kinetic energy of photoelectrons caused by this resorption (it would be enough to consider one or two hard series) are presented. Calculation of the spectrum of photoelectron energy yield in TeInSe_2 monocrystal for 0.1-0.5 A range of X-ray radiation is conducted by the developed methods.
Possibilities of applying the Pb/sup 203/ isotonic solution without a carrier as a label of blood erythrocytes, are found. There is a number of advantages in the Pb/sup 203/ isotonic solution without a carrier, such as a high label efficiency (above 95%), a short half-life (52 hours), and a low radiation dose. These factors prove to be favourable as compared with Cr/sup 51/ widely used for these purposes. Besides, of all preparations used up to now to treat erythrocytes and to scan the spleen, it is only in the case of Pb/sup 203/ isotonic solution without a carrier that no weight amounts of chemical substances do not enter the organism.
In order to improve the capacity and service life of cathodes, the effect of carboxy-methyl cellulose, soot, silica gel and fibres was examined. Structural tests and electrical and electro-chemical measurements are used for this. The additives can affect crystallization in the manufacturing stage of the electrodes and can increase the storage capacity for water and the electronic conductivity. They act to stabilize the mass in cyclic operation. Soot additive has little effect on the properties of the electrode, but the other substances increase the service life or the use of the mass. (LU).
Studies dialysis kinetics of zinc dialkyldithiophosphates, detergent-dispersing agents, alkyl-phenols and base oils. It was established that diffusion kinetics of oil hydrocarbons through membrane of individual compounds and narrow fractions is described by Brinzinger's formula, which is identical to the kinetic reaction formula of the 1st order. It was shown that dialysis can be utilized to determine the content of the ''active substance'' only in sulphonate and alkylsalycilate additives. Increasing temperature from 20 to 40/sup 0/ results in an increased dialysis constant for all studied products by 1.4-1.9 times.
In the present work, using a pad-on-disc-type wear tester, the tribological properties of the pad next to the disk made of cast iron were investigated with changing the substance of the components. As well, micro-structural characterisation of braking pads was performed using scanning electron microscopy and also temperature outcome of the pads was examined at the temperatures of 50-400 "oC in the pressure of 1050 and 3000 kPa. Finally, the effect of environment to the pads was studied in water, salty water, oil and braking liquid media.
A solid electrolytic capacitor having a solid electrolyte comprising manganese dioxide dispersed in an aromatic polyamide capable of further cure to form polyimide linkages, the solid electrolyte being disposed between a first electrode made of valve metal covered by an anodic oxide film and a second electrode opposite the first electrode. The electrolyte autogenously produces water, oxygen, and hydroxyl groups which act as healing substances and is not itself produced pyrolytically. Reduction of the manganese dioxide and the water molecules released by formation of imide linkages result in substantially improved self-healing of anodic dielectric layer defects.
The NPPs safety system in Germany is discussed. It is shown that there exists no threat for the German NPPs at the peace times. They release insignificant quantities of radioactive substances into the water and atmosphere. The average equivalent dose constitutes 0.0005 mSv annually. The annual equivalent dose for the personnel is equal to 4.4 mSv. At the same time, the NPPs contribute to a certain degree to the environmental medium improvement, preventing the ingress therein of the sulfur and carbon dioxide, dust and nitrogen oxides by application of fossil fuels. Attention is also paid to reprocessing facilities and also to the nuclear fuel wastes disposal. The advantages of the nuclear power engineering in comparison with the fossil fuel power engineering are enumerated
The first biogas plant using the Plauen method has been operated without failures in the Saxon Vogtland since May 1987. This large scale anaerob treatment plant which is the first one in Germany handles besides agricultural recidual substance both municipal and industrial organic residues. The results show clearly that fermentation is a real alternative to composting, combusting and deponing. (orig.)
The physical foundations are described of radionuclide X-ray fluorescence analysis (RXFA) and the table shows the values of K- and L-absorption thresholds and the K- and L-line energies of elements. The calculation of the intensity of characteristic radiation during RXFA proceeds from relations derived for conventional X-ray fluorescence analysis. The choice of the radionuclide source is ruled by the nature of the analysed substance and the used detection technique. The diagram shows the areas of radionuclide sources and the energy of the fluorescence radiation of elements. The table shows the spectra of radionuclide sources suitable for the purposes of RXFA measured by semiconductor Si(Li) and Ge(Li) detectors. (ES).
s. Manufacturing Yes No. t. Renewable Energy Yes No ...... Computational software is sought to simulate of the response of advanced composite fan ...... Thermal energy storage and utilization using bulk or processed regolith ...... scale up roadmap to 1 to 2+ meter class space qualifiable flight optics systems. ...
Lateral and vertical variabilities in the bulk and mechanical properties of silicic volcanic tuff at the potential nuclear waste repository site in Yucca Mountain, NV have been evaluated. Laboratory measurements have been performed on tuff specimens recovered from boreholes located to support the design of the Exploratory Studies Facility/North Ramp. The data include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. Data from eight boreholes aligned in a northwest-southeast direction have been collected under the required quality assurance program. Three boreholes have penetrated the potential repository horizon. The information collected provides for an accurate appraisal of the variability of rock properties in the vicinity of the boreholes. As expected, there is substantial variability in the bulk ...
Contrary to the electronic excitation induced phenomena of desorption and sputtering, we observed incorporation of oxygen in a thin Fe film during its irradiation with swift heavy ions. It is observed that the adsorbed oxygen diffuses in to the Fe film. The incorporation of oxygen and its diffusion in the bulk of the film is a manifestation of extremely large electronic energy deposition by the incident ions. It is shown that the experimentally observed high diffusivity of oxygen in Fe during irradiation is due to the existence of transient melt phase of Fe.
We present a general procedure to construct the first law of thermodynamics on the apparent horizon and illustrate its validity by examining it in some extended gravity theories. Applying this procedure, we can describe the thermodynamics on the apparent horizon in Randall-Sundrum braneworld imbedded in a nontrivial bulk. We discuss the mass-like function which was used to link Friedmann equation to the first law of thermodynamics and obtain its special case which gives the generalized Misner-Sharp mass in Lovelock gravity.
By magnetron sputtering model steel films with specific properties can be prepared for purposive surveys. By changing the deposition parameters certain properties of these films can be influenced. For this thesis steel films with 18% Cr and 8% Ni have been prepared in order to study specific parameters on the corrosion resistance of bulk stainless steel. Chemical composition, microstructure, and surface morphology of these films have been characterized. In comparison to bulk steel sheets with the same chemical composition they have a smaller grain size and a ferritic structure. In contrast to bulk steel sheets they don`t contain any nonmetallic inclusions like Mn-sulfides. The influence of these structural differences on the corrosion resistance has been studied. For this purpose the electrochemical properties of the sputter-deposited steels have been compared with the properties of steel sheets with a similar chemical ...
When liquids are confined in nano-scopic dimensions, their properties differ from the corresponding bulk liquid, due to their reduced dimensionality and surface effects. Phase transition temperatures and pressures are often shifted from the bulk values and new phases can appear due to the strong interactions of the molecules with the confining walls. We have studied the structural and dynamical properties of aromatic liquids such as benzene, toluene, and ortho-terphenyl confined in nano-porous materials, MCM-41 and SBA-15, synthesized and characterized in our laboratory. A non-trivial dependence of the glass transition temperature, T{sub g}, on the pore size and surface treatment of nano-porous materials is confirmed and interpreted as resulting from a competition between the fluid-wall and fluid-fluid intermolecular interactions. An increase of T{sub g} is observed for small pore sizes and attractive surface while T{sub g} decreases for non ...
A preliminary database has been developed that will allow mineralogy and bulk-rock geochemical information to be managed under configuration control and facilitate electronic querying. The database is currently developed in Microsoft Access as a collection of tables, views, and entry forms. Each field and table has been described in a data dictionary.
Classical molecular dynamics simulations are carried out to investigate the salvation shell exchange kinetics of potassium ion in bulk water, chloroform, and carbon tetrachloride. The reactive flux method is used to compute the dissociation rates. The influence of the solvent on the reaction rates and kinetic properties of this exchange process will be discussed. Comparison will be also be made to the prediction of the Grote-Hynes theory.
Simian virus 40 transcriptional complexes could be extracted from CV1 cells late in infection and separated from the bulk of inactive viral chromatin. Sucrose gradient sedimentation, cesium sulfate...Full Text Available
The mechanism of chemical poisoning of model heterogeneously catalyzed reactions on transition metal surfaces is studied. Clean Mo(001) surfaces were characterized; results suggest a first-layer contraction of 10% of the bulk interlayer spacing. Characterization of clean Co(0001) surfaces is underway. Decomposition of formic acid on Mo(001) surfaces is being studied. (DLC)
After a brief survey of the known level measurement methods the particularities of the radiometric measurement of the still utilisable residual volume of a bulk material in a large bin are discussed. At constant angle of repose the measurement in a suitably positioned plane of measurement suffices, at variable angle of repose two planes of measurement are required. The probable working ranges for a 1300-t lime bin are estimated.
We describe the continued development of a portable, real-time neutron spectrometer. The spectrometer is composed of two distinct detector systems: a Helium 3 gas filled proportional counter for the lower neutron energy interval between 20 KeV and 2 MeV and a bulk silicon solid state detector for the higher energy interval between 2 MeV and 500 MeV. Modeling and experimental results with mono-energetic neutron beams are reported.
We describe the early stage of development of an engineering model portable, real-time neutron spectrometer. Several systems of two distinct detector types, a helium 3 gas filled proportional counter and a bulk silicon solid state detector, will be necessary to cover the energy range from thermal to 500 MeV. The advantages and disadvantages of using a moderator were investigated experimentally.
A focused ion beam (FIB) system has been applied to prepare a thin foil specimen of Si, MgO and alumina which contained cracks in the plan of foil. It was possible to observe a much larger area at and near a crack tip than has been hitherto possible. FIB was also applied to observation of microstructure near a crack tip evolved during severe rolling contact fatigue in a steel.
We report the oxygen, hydrogen, and deuterium effects on nitrogen implantation of stainless steel. Oxygen is absorbed on the surface creating a potential barrier and diminishing the nitrogen retention. Deuterium removes more oxygen from the surface than hydrogen, augmenting the nitrogen chemical potential and yielding faster nitrogen diffusion into the bulk material.
This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.
This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.
In this work a Ni-based superalloy GMR 235 was investigated. We determined convenient metallographic methods for preparation of bulk metallographic specimens, extraction carbon replicas, transparent metallic foils and minor phase extraction. In addition, the alloy microstructure was characterised using different metallographic techniques. (orig.)
Using commercial AZ31 magnesium alloy sheets, we produced a foamable preform sheet containing titanium hydride (TiH{sub 2}) powder through diffusion-bonding and hot-rolling of four cycles. Heating the preform sheets in Ar atmosphere, we obtained closed-cell magnesium alloy foams with various porosities. The foamed specimen at 883 K showed the maximum porosities of 77%. (orig.)
Laser direct-write etching of the refractory metals Mo and W was developed using reactions in chlorine and nitrogen trifluoride vapors. Rate and high spatial resolution are simultaneously optimized using a two-vapor halogenation/development sequence, based on surface modification. Local-area laser chlorination of the metal surface is used to predispose areas to subsequent bulk etching.
Coarse components in the charge, i.e. >6 mm material, display higher ash, a lower volatile matter and a smaller proportion of caking components. Bulk density and moisture levels were studied over a wide range of size reductions (60-85% blast furnace coke. Laboratory work should be checked in practical runs working with 74-76% <3 mm charge material.
Systems with small sizes show significant changes compared to the bulk system. These changes are of major interest regarding the size reduction of technological applications. The hydrogen-metal system can be used as a model alloy to study small size features: shifted phase boundaries and sloped isotherms are found and, also, new materials structures. Most features can be attributed to surface- and interface contributions as well as to mechanical stress. (Abstract Copyright [2004], Wiley Periodicals, Inc.)
IntroductionThe phenotypic and functional differences between cells that initiate human breast tumors (cancer stem cells) and those that comprise the tumor bulk are difficult to...Full Text Available
We consider a generalization of the DGP model, by adding a second brane with localized curvature, and allowing for a bulk cosmological constant and brane tensions. We study radion and graviton fluctuations in detail, enabling us to check for ghosts and tachyons. By tuning our parameters accordingly, we find bigravity models that are free from ghosts and tachyons. These models will lead to large distance modifications of gravity that could be observable in the near future.
There have been no radically new commercial bulk explosives since Atlas Powder Company's introduction of emulsions onto the market in 1968. But the effectiveness, safety and management of these familiar explosives is continuously being improved by the development of blast design techniques, explosives delivery and initiation systems, and monitoring methods. The author looks at developments in blasting technology and discusses experiences with Handibulk emulsion delivery systems.
Refeeding starved rats with an elemental diet resulted in a marked increase in crypt cell production rate (CCPR) in the proximal small intestine but not in the distal regions of the gut. Little effect...Full Text Available
Physico-chemical studies were carried out on a sample of red mud collected from NALCO, Orissa, after calcination up to 1,200 C at an interval of 100 C. The observed change in properties like surface area, particle size, bulk density and mineral phases etc., can be profitably used while finding an appropriate application of this polluting waste from alumina plants.
We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and antiferromagnet. The new uncompensated magnetization near the interface responds to applied field, while the uncompensated spins in the antiferromagnetic bulk are pinned, thus providing a means to establish exchange bias.
The focus of general public concern on the environment results in the use of underground lines being considered since they offer alternative or interesting complementary solutions for the bulk transmission of electrical energy. This leads to the installation of underground cables in some areas, where overhead lines would automatically have been considered in the past.
The aim of this work is to compile an inventory of the main characteristics (chemical, morphological, mineralogical and grain size parameters) of the bulk cargo materials and of the material emitted during different port operations for possible use as tracers of the fugitive PM emission sources. For all cases, the tracer characteristics determined for each bulk material were also identified in the corresponding PM material emitted. This inventory could assist the harbour authorities to identify the origin of high PM events recorded by air quality monitoring networks in harbour areas, and could also help modellers to predict the impact of harbour activities on ambient PM levels. The harbour of Tarragona (north-east Spain) was selected for this study given the high volume of solids in bulk handled. To this end, 12 handling operations of selected materials (clinker, phosphate, pyrite ash, Mn mineral, fine Si-Mn, coke (coal), ...
The adhesion strength of polybutylene terephthalate (PBT) on aluminum was investigated using density functional theory-based total energy calculations. Aluminum atom was connected to a PBT monomer at different orientations and total energies were calculated in order to determine the most stable orientation. The energy differences showed that the Al oriented at 180degree with the ester group of the monomer bonded strongly. Using this orientation, the PBT monomer-adhesion on aluminum surface and the aluminum atom adhesion on PBT bulk were also investigated.
Bulk electronic properties and photoelectron spectra of UNiAl and UPdSn are discussed in terms of varying degree of the localization of 5f states. For UPdSn with #gamma#=5 mJ/mol K"2, localized 5f states can be expected, but photoemission shows still the presence of 5f states at E_F. (orig.).
Nanosized particles are important because of their unique properties, different from the bulk, which leads to their enhanced catalytic, photocatalytic and electronic properties. This work has dealt with three different nanoparticle systems in the context of three different aspects of nanoparticle properties: (a) photocatalytis (TiO2/metal) system, (b) luminescence (CdSe) (c) alloying (Pt-Ag and Pd-Ag). The initial photocatalytic enhancement obtained by adding noble metal on semiconductor nanoparticles, degrades as fast as in 15 minutes and questions their long-term performance. XANES measurements on such irradiated systems like TiO2/Au, TiO2/Pt, TiO2/Ir indicates a positive oxidation state of these noble metals which renders them as recombination centers for photo-excited electrons and explains the decreased photocurrent. The oxidation is caused by holes. The EXAFS results also indicate a change of the interfacial structure under the effect of UV-irradiation, thus ...
Field emitter devices are being developed for the gigatron, a high-efficiency, high frequency and high power microwave source. One approach being investigated is porous silicon, where a dense matrix of nanoscopic pores are galvanically etched into a silicon surface. In the present paper pore morphologies were used to characterize these materials. Using of Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) images of both N-type and P-type porous layers, it is found that pores propagate along the <100> crystallographic direction, perpendicular to the surface of (100) silicon. Distinct morphologies were observed systematically near the surface, in the main bulk and near the bottom of N-type (100) silicon lift-off samples. It is seen that the pores are not cylindrical but exhibit more or less approximately square cross sections. X-ray diffraction spectra and electron diffraction patterns verified that bulk porous ...
We present computer modeling along with experimental data on the formation of sharp conical tips on silicon-based three-layer structures that consist of a single-crystal Si layer on a 1 {mu}m layer of silica on a bulk Si substrate. The upper Si layers with thicknesses in the range of 0.8-4.1 {mu}m were irradiated by single pulses from a KrF excimer laser focused onto a spot several micrometers in diameter. The computer simulation includes two-dimensional time-dependent heat transfer and phase transformations in Si films that result from the laser irradiation (the Stefan problem). After the laser pulse, the molten material self-cools and resolidifies, forming a sharp conical structure, the height of which can exceed 1 {mu}m depending on the irradiation conditions. We also performed computer simulations for experiments involving single-pulse irradiation of bulk silicon, reported by other groups. We discuss conditions under which different types ...
The bulk of the results from this project, besides being found in the research reports, are in the form of two theses presented for advanced degrees by two different students at two different institutions. Francis E. Porbeni is a Master`s Degree student in Chemistry at Clark Atlanta University and has prepared his Master`s Thesis entitled Simultaneous SO{sub 2} Oxidation and NO Decomposition over Copper Oxide on {gamma}-Alumina Catalysts: An Infrared Diffuse Reflectance Study. Sumit Rao, a Ph.D. student in Chemical Engineering at the Georgia Institute of Technology has defended his thesis entitled Role of Copper Ensemble Size in Silica and Zeolite Supported Catalysts for Nitric Oxide Decomposition. These two documents, which will be forwarded when final copies are available, provide the details of the bulk of the research accomplished over the duration of this project. These two documents are summarized, and other results from the project are ...
The Oak Ridge National Laboratory (ORNL) is developing a treatment process for remote-handled (RH) liquid transuranic mixed waste governed by the concept of minimizing the volume of waste requiring disposal. This task is to be accomplished by decontaminating the bulk components so the process effluent can be disposed with less risk and expense. Practical processes have been demonstrated on the laboratory scale for removing cesium 137 and strontium 90 isotopes from the waste, generating a concentrated waste volume, and rendering the bulk of the waste nearly radiation free for downstream processing. The process is projected to give decontamination factors of 10{sup 4} for cesium and 10{sup 3} for strontium. Because of the extent of decontamination, downstream processing will be contact handled. The transuranic, radioactive fraction of the mixed waste stream will be solidified using a thin-film evaporator and/or microwave solidification system. ...
In the present study a partial replacement of aggregate with two different ratios of waste rubber (5%, 10%) with the addition of a constant ratio of rice husk ash (RHA), 5% was carried out. The hardened cement mortar used the optimum water of consistency. The specimens were molded into 1 inch cubic moulds .The specimens were first cured for 24 hours, at 100% relative humidity and then cured under tap water for 3, 7 and 28 days followed by irradiation at different doses of gamma irradiation namely 5 and 10 kGy. The physico-chemical and mechanical properties such as compressive strength, total porosity and bulk density were studied for the three types of specimens. The results showed that the values of the compressive strength, bulk density and chemically combined water of the blended cement mortar paste (OPC-RHA) increase ,while blended cement mortar paste with 5% RHA and 5, 10% waste rubber decrease. The results were confirmed by scanning ...
The effect of Mo addition on the glass-forming ability (GFA), magnetic properties, mechanical properties and corrosion resistance of (Fe0.76Si0.096B0.084P0.06)100-xMox (x=0, 2, 4 and 6at.%) bulk glassy alloys (BGAs) with high Fe contents was investigated. The 2at.% Mo addition makes the alloy composition approach towards a eutectic point, which could result in an increase in the GFA. The BGA rod with diameters up to 3.5mm was produced by copper mold casting. These BGAs exhibit a rather high saturation magnetization of 0.98-1.51T and lower coercive force of 1.7-2.1A/m. A significant improvement in corrosion resistance was observed with microalloying Mo element in 1N H2SO4 solution. Furthermore, these Fe-based BGAs show super-high strength of ~3.3GPa and Young's modulus of 200GPa.
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. Samples prepared from the blends exhibited high yield stresses of 440 and 550 MPa after compression, and they did sustain work hardening. Tests conducted before and after compression up to 50 % ...
A number of agricultural and engineering uses for fixated flue gas desulfurization (FGD) material exist; however, the potential for leaching of hazardous elements has limited widespread application and the processes controlling the leaching of this material are poorly understood. In this study, a flow-through rotating-disk system was applied to elucidate the relative importance of bulk diffusion, pore diffusion, and surface chemical reaction in controlling the leaching of fixated FGD material under pH conditions ranging from 2.2 to 6.8. Changing the hydrodynamics in the rotating disk system did not affect the leaching kinetics at both pH 2.2 and 6.8, indicating that bulk diffusion was not the kinetic-limiting step. Application of the shrinking core model (SCM) to the data suggested a surface reaction-controlled mechanism, rather than a pore diffusion mechanism. The leaching of fixated FGD material increased with decreasing pH, suggesting it can ...
Two novel organic n-type semiconductors are investigated due to their function as electron acceptor for applications in organic electronic devices to widen the knowledge of how molecule structure influences the excitation processes in organic electronics. Bispyrenylfullerene and Octadecyl-Capronacidesterfullerene are C{sub 60} derivates with sidechains more featured compared to the commonly used[6,6] phenyl-C{sub 61}-butyric acid methyl ester (PCBM). In bulk heterojunction devices regioregular poly(3-hexylthiophene) (P3HT) was used as donor. The materials, pristine and in blend, were studied in view of light absorption, their quenching abilities of the P3HT photoluminescence as well as excited states. Furthermore, the spin state of the excited states was determined by light-induced electron spin resonance. Combining these complimentary experimental techniques, we obtained information on the generation of excited states, their nature, and the efficiency of the ...
Bulk nanocrystalline pure iron rods were fabricated by the equal channel angular pressure (ECAP) technique up to eight passes. The microstructure and grain size distribution, natural immersion and electrochemical corrosion in simulated body fluid, cellular responses and hemocompatibility were investigated in this study. The results indicate that nanocrystalline pure iron after severe plastic deformation (SPD) would sustain durable span duration and exhibit much stronger corrosion resistance than that of the microcrystalline pure iron. The interaction of different cell lines reveals that the nanocrystalline pure iron stimulates better proliferation of fibroblast cells and preferable promotion of endothelialization, while inhibits effectively the viability of vascular smooth muscle cells (VSMCs). The burst of red cells and adhesion of the platelets were also substantially suppressed on contact with the nanocrystalline pure iron in blood circulation. A clear ...
Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of the composite to such an extent that there is virtually very little difference between vacuum impregnation and normal ...
CeO{sub 2} undergoes a first-order phase transition from fluorite to {alpha}-PbCl{sub 2}-type structure under high pressure. To evaluate the changes in physical properties of CeO{sub 2} nanomaterials as the particle size decreasing, high-pressure Raman study under quasi-hydrostatic condition has been performed on CeO{sub 2} nanospheres self-assembled by 5 nm CeO{sub 2} nanoparticles at room temperature. Surprisingly, as the pressure elevate to 34 GPa, the CeO{sub 2} nanospheres still retain the cubic fluorite-type structure, indicating the sample is more stable than the bulk counterpart. Whereas, previous high-pressure studies show the phase transition at 22.3/26.5 GPa for 12 nm CeO{sub 2} nanoparticles, which is less stable than the bulk materials. The enhancement of phase stability might be attributed to the increase of surface energy of CeO{sub 2} nanospheres as the size of the building units decrease. (Copyright copyright 2011 WILEY-VCH ...
Functionalizing nanoparticle surfaces is essential for achieving homogeneous dispersions of monodisperse particles in polymer nanocomposites for successful utilization in engineering applications. Functionalization reduces the surface energy of the nanoparticles, thereby limiting the tendency to agglomerate. Moreover, reactive groups on the surface can also participate in the polymerization, creating covalent bonds between the inorganic and organic phases. In this paper, a fluidized bed inductively coupled plasma (FB-ICP) reactor is used to break apart the agglomerates and functionalize commercial TiO2 nanoparticle powders in a batch of several grams. The fluidized bed could be implemented into a continuous flow reactor, potentially making this a viable method to treat larger quantities of commercial powders. The particles are treated with acrylic acid (AA) and tetraethylorthosilicate (TEOS) plasma and the functionalized particles were collected separately from ...
A novel Ni and Cu-free Zr-based bulk metallic glass (BMG) system with enhancement of glass-forming ability (GFA) and bio-corrosion resistance was prepared by copper mold casting by the addition of Ag. It was found that the addition of Ag can considerably enhance the glass-forming ability, as indicated by the increase of the critical glass dimension from 3 mm diameter of the ternary system to over 10 mm in the alloy of Zr_5_3Co_1_8_._5Al_2_3_._5Ag_5. The bio-corrosion behaviors of the Zr-based BMGs in phosphate buffered solution (PBS) were investigated by electrochemical polarization at 310 K. It was found that the addition of appropriate amount of Ag can enhance the corrosion resistance of the BMGs. The X-ray photoelectron spectroscopy (XPS) indicated that the formation of an Al_2O_3-enriched passive film is mainly responsible for the high corrosion resistance of Ag-bearing alloy in phosphate buffered solution.
First-principles plane-wave pseudopotential and full-potential linearized-augmented plane-wave methods have been used to study the elastic and electronic properties of several potential superhard RuO_2 phases. The structures, relative stabilities, and the elastic constants and bulk moduli of these phases have been calculated within local-density approximation (LDA) and generalized gradient approximation (GGA). In RuO_2, the LDA and GGA approximations yield smaller and larger lattice constants, respectively, for the Pa3-bar-RuO_2 structure. The internal structural parameter for oxygen atoms in the Pa3-bar structure has a volume dependence that differs from the experimental result and therefore implies a significantly different compression mechanism. The calculated bulk moduli are very similar for the fluorite and Pa3-bar structures and therefore apparently independent of the internal structural parameter. The structure and stability of a ...
The steady state surfaces of ion bombarded 3C-, 4H- and 6H-SiC samples were studied by means of reflected electron energy loss spectroscopy (REELS). The REELS exhibit a well-defined loss peak in the region of about 20 eV. The position of the maximum of the loss peak depends on the bombarding ion energy (decreasing with increasing ion energy), and on the primary electron beam energy (increasing with increasing primary energy). This behavior can be explained if we suppose that the plasmon energy in the altered layer (produced by ion bombardment) is different from that of the unaltered bulk. In this case the measured loss peak is the sum of two overlapping plasmon peaks. With modeling the system as a homogeneous altered layer and a homogeneous unaltered substrate the plasmon energy in the altered layer was derived to be 19.8 eV. The large change of the plasmon energy with respect to the bulk value of 23 eV is explained by a thin low density ...
Results from a heavily fouled 19 tube C-E model boiler test to investigate the potential for egg crate corrosion in aggressively fouled AVT chemistry are reported. Substantial support plate and egg crate corrosion was produced in this test. Carbon steel drilled support plates exhibited extensive denting which resulted in flow hole ligament cracking. Corrosion of the carbon steel egg crate, through-wall at areas of tube contact, resulted in denting of the Alloy 600 heat transfer tubes. Corrosion performance of the 409 stainless steel egg crate was improved compared to the carbon steel egg crate although localized through-wall corrosion was noted. The results from the above test and previously reported tests were compared based on the following simplifying assumptions: maximum dent size and/or corrosion penetrations utilized, average bulk water chloride concentrations, pilling bedworth ratios, pot and model boilers data are equivalent, heat flux not significantly ...
We study the condensation of localized closed string tachyons on AdS orbifolds both from the bulk and boundary theory viewpoints. We first extend the known results for AdS{sub 5}/Z{sub k} to AdS{sub 3}/Z{sub k} case, and we proposed that the AdS{sub 3}/Z{sub k} decays into AdS{sub 3}/Z{sub k'} with k{sup '} < k. From the bulk viewpoint, we obtain a time-dependent gravity solution describing the decay of AdS orbifold numerically. From the dual gauge theory viewpoint, we calculated the Casimir energies of gauge theory vacua and it is found that their values are exactly the same as the masses of dual geometries, even though they are in different parameter regimes of 't Hooft coupling. We also consider AdS{sub 5} orbifold. The decay of AdS{sub 5}/Z{sub k} is dual to the transition between the vacua of dual gauge theory on R{sub t} x S{sup 3}/Z{sub k}. We constructed the instanton solutions describing the ...
Laboratory testing at Combustion Engineering has indicated promise in controlling simulated steam generator tube denting through chemical neutralization. Testing was limited to on-line treatment, and two neutralizers have been evaluated: calcium hydroxide and boric acid. On-line treatment with calcium hydroxide successfully halted active denting whenever the bulk calcium concentration (in ppm) equaled or exceeded the bulk chloride concentration (in ppm). Calcium hydroxide also was effective as an alternative to ammonia as a pH controlling agent in two tests conducted without ingress of chloride. On-line treatment with boric acid consisted of a four-day soak at simulated low (approximately 30 percent) power with 50 ppm B followed by one month full-power operation with 10 ppm B. This treatment also halted denting. Nondestructive and destructive examination of test boilers gave no indication of adverse side effects associated with either ...
The grain boundary misorientation distribution of 203 grain boundaries in bulk processed high Tc superconductor YBa_2Cu_3O_7_-_#delta# with five processing conditions;, was studied. Two complementary analytical approaches, Grain Boundary Misorientation Distribution (GBMD) from the random description, using a hypothesis test and #chi#"2 analysis, and Grain Boundary Character Distribution (GBCD), using the Coincidence Site Lattice (CSL) model, were applied. The GBMD and GBCD both showed grain boundary evolution departing from a random distribution above 935 C processing temperature. The GBCD analyses indicated an approximately linear increase in the population of CSL-related boundaries, among which the tetragonal CSL (c/a #not =# 3) boundaries grew in the same trend while orthorhombic boundaries (c/a = 3) became stagnated. The results from comparing the corresponding GBCD and volume averaged J_c for each batch indicated that the tetragonal CSL boundaries were oxygen ...
Fine ceramics center (JFCC) succeeded in the higher precision of thermal diffusivity measurement by the laser flash. This results are part of 'the research on thermophysical property measurement technique and standard substance of the functional material' by the intelligent establishing of a base promotion system of Science and Technology Agency. Cooperative research. thermal diffusivity with Natl. Res. Lab. of Metrology is one of the representative thermophysical property. The speed in which a heat transmits of the material is shown, and it is indispensable to the design of the high-temperature member subject. JFCC heralds the world as a standard substance for the thermal diffusivity measurement; 'TD-AL' using the alumina material is developed and is supplied in the spring in last year. Laser flash which uses laser beam for the heat source is general for the measurement. However, there was grinding undercut ...
Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).
Wood plastic composite (WPC) has been prepared with a low grade wood simul (Salmalia malabarica) of Bangladesh under Co-60 gamma irradiation using MMA as the bulk monomer combined with methanol as the swelling solvent at different urea concentrations. Effect of a second solute such as NVP, TPGDA and TMPTA in the impregnating solution is evaluated. NVP appears to be the best co-additive/second solute among all the additives used to yield the composite with the highest polymer loading (PL) and tensile strength (TS) at 0.5% urea concentration. (author).
We calculate quark-antiquark potentials using the relationship between the expectation value of the Wilson loop and the action of a probe string in the string dual. We review and categorize the possible forms of the dependence of the energy on the separation between the quarks. In particular, we examine the possibility of there being a minimum separation for probe strings which do not penetrate close to the origin of the bulk space, and derive a condition which determines whether this is the case. We then apply these considerations to the flavoured resolved deformed conifold background of Gaillard et al. We suggest that the unusual behaviour we observe in this solution is likely to be related to the IR singularity which is not present in the unflavoured case.
Solid solution-strengthened nickel base alloys have been used for nuclear stream generator tubing in pressurized water reactors since the beginnings of commercial nuclear power. The purpose of this paper is to recap and update the authors understanding of the relationship between processing, resulting structure, and properties for Alloy 600 and to discuss the requirements for optimized performance in both primary and secondary environments. Potential replacement materials and their performance will be discussed. Also discussed is the role and importance of system chemistry, bulk and local, and control and its relationship to performance. A discussion of potential mechanisms of environmentally assisted failure is also discussed.
Solid solution-strengthened nickel base alloys have been used for nuclear stream generator tubing in pressurized water reactors since the beginnings of commercial nuclear power. The purpose of this paper is to recap and update the authors understanding of the relationship between processing, resulting structure, and properties for Alloy 600 and to discuss the requirements for optimized performance in both primary and secondary environments. Potential replacement materials and their performance will be discussed. Also discussed is the role and importance of system chemistry, bulk and local, and control and its relationship to performance. A discussion of potential mechanisms of environmentally assisted failure is also discussed.
This paper presents anew design concept for a gamma irradiation plant for the continuous processing of pumpable liquids. Typical applications of such a plant include: the irradiation vulcanisation of natural latex rubber; disinfection of municipal sewage sludge for agricultural use; sterilisation of liquids in the pharmaceutical and cosmetics industries; industrial processing of bulk liquids The authors describe the design and operation of the latex irradiator now operating on a small production scale in Malaysia and proposed developments. The design allows irradiation processing to be carried out under an inert or other gaseous environment. State-of-the-art computer control system ensures the fully automatic processing operation needed by industrial computers.
Defects ~10 nm in size, with number densities ~10^{10} cm^{-2}, form spontaneously beneath ion-milled, etched, or HF-dipped silicon surfaces examined in our Ti-ion getter-pumped transmission electron microscope (TEM) after exposure to air. They appear as weakly-strained non-crystalline intrusions into silicon bulk, that show up best in the TEM under conditions of strong edge or bend contrast. If ambient air exposure is <10 minutes, defect nucleation and growth can be monitored {\\em in situ}. Possible mechanisms of formation are discussed.
The excess energy of several III-V and II-VI strained-layer semiconductor superlattices (AC)_p(BC)_p is studied as a function of the repeat period p and orientation G=[001], [110], [111], and [201], using first-principles calculations. We discover a number of universal features, including the predicted instability for nearly all p's and G's with respect to bulk disproportionation, the identification of chalcopyrite as a metastable ordered structure, and the stability of all thin epitaxial [110] and [201] and most common-anion [001] superlattices relative to coherent phase separation.
Spray forming is an advanced materials processing technology that converts a bulk liquid metal to a near-net-shape solid by depositing atomized droplets onto a suitably shaped substrate. By combining rapid solidification processing with product shape control, spray forming can reduce manufacturing costs while improving product quality. De Laval nozzles offer an alternative method to the more conventional spray nozzle designs. Two applications are described: high-volume production of aluminum alloy strip, and the production of specialized tooling, such as injection molds and dies, for rapid prototyping.
To study the plasma evolution and spatial structure at the L/H transition, the double hysteresis is examined by use of the 1-dimensional transport model equations. Three mechanisms for the bipolar losses, i.e., the loss cone loss, collisional bulk viscosity loss of ions and the anomalous loss are simultaneously retained. Five-fold multiple bifurcations are found to exist at the plasma edge, similar to the previous 0-dimensional study. Double hysteresis causes a self-generated oscillation, which is attributed to the compound dither, a kind of ELMs. Spatio-temporal evolution of the compound dither is analyzed. (author)
The author points out that errors in certain measurements are preventing improvements in coke: thermocouples (errors caused by the thermocouple installation and variations in the temperature of the cold junctions); dilatometers (errors caused by size of heating block and differences in starting temperature led to differences between two instruments); errors in measuring the bulk density of the coking charge. The elimination of these sources of error in determinations of the technological and physical properties of coke oven charge should assist in the study of other problems which are delaying improvements in blast furnace coke production.
We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.
A simple theory for predicting the convective energy loss from side-facing cavity receivers in windless environments has been developed. The approach used is to determine the velocity distribution of the incoming air in the aperture plane (and thereby the rate of mass entrainment); and then to estimate the bulk temperature of the heated emerging air. The convective loss is then calculated from an energy balance. To illustrate this theory, numerical results applicable to the 2.15 meter cubic cavity being tested in the laboratory are provided.
A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H/sub 2/O approx. = 1) at a reduced pressure (less than or equal to4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.
A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H_2O #approx =# 1) at a reduced pressure (#<=#4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.
Carrier-free radioisotopes of tungsten, "1"7"6","1"7"7W, and their corresponding daughter radionuclides "1"7"6","1"7"7Ta, have been produced in holmium target by heavy ion activation with "1"6O"5"+ beam. An attempt has been made to separate these carrier-free radionuclides from bulk holmium target through LLX using cation exchanger HDEHP. (author)
Bulk properties such as the binding energies, r.m.s. radii and deformation parameters are calculated for the light (Z=2-8) even-mass nuclei using deformed relativistic mean-field theory. A comparison between L1, NL1 and NL2 parameter sets are given. The effects of pairing for open-shell nuclei have been investigated. The calculation is extended to nuclei near the proton- and neutron-drip line. Reasonable agreement with experiment is achieved for NL1 and NL2 parameter sets. (orig.).
Pumped storage plants (PSP) enable the storage of energy with rated capacities of order of GW at a single site. Reservoirs allow charging and discharging times of at least hours, sometimes days or even up to several weeks. Short ramp-up times permit the participation in the secondary reserve market as a standing reserve. For bulk energy storage, PSP reach the lowest, specific costs. In the EU27 countries, Norway and Switzerland, a total of 44 GW of pumped storage capacity is installed. The utilisation of PSP strongly correlates with the amount of conventional generation capacity, rather than with topographical options. (orig.)
Discussed are various aspects of heating oil `sludge`: How it forms, typical problems it causes, how sludge-control additives work, what should be expected of them, and what happens in a contaminated system when such additives are used. Test results from laboratory and field experiments demonstrate that performance of commercially available additives varies greatly. The concept of `end-of-the-line` treatment is described and compared with bulk fuel treatment. A procedure is described whereby a retailer can test additives himself, and thus determine just what those additives will or will not do for his business. Finally, the economics of an effective treatment program are outlined.
The report contains highlights of the achievements of the IAEA Co-ordinated Research programme on Evaluation on the Use of Bulk Reagents for the Production of "9"9Tc_m Radiopharmaceutical and Kits, the participants' summary reports (Argentina, Chile, Greece, India, Indonesia, Japan, Malaysia, Portugal, Russian Federation, Thailand, Uruguay, United States of America), recommended product protocols for five compounds and the participants' recommendations regarding continued support and further directions of co-ordinated research work. Refs, 6 figs, 8 tabs, 6 schemes.
Ammonia gas (NH{sub 3}) has been used as a nitrogen source for plasma source ion implantation processing of electroplated chromium. No evidence was found of increased hydrogen concentrations in the bulk material, implying that ammonia can be used without risking hydrogen embrittlement. The retained nitrogen dose of 2.1 {times} 10{sup 17} N-at/cm{sup 2} is sufficient to increase the surface hardness of electroplated Cr by 24% and decrease the wear rate by a factor of 4.
In the last 30 years the production of electricity in the USSR has increased 14-fold, probably attaining 1540 billion kWH in 1985. Nuclear generation will provide the bulk of future increases of consumption, using both water-cooled and uranium/graphite reactors; stations of up to 1.5 million kW are in service. The USSR is also in the fore-front of attempts to exploit thermonuclear power. The USSR is also conducting experiments with renewable sources of energy such as solar, geothermal, wind and wave power and with magnetohydrodynamic generation. (D.A.J.).
The solvation properties of a chlorine ion in small water clusters are investigated using state-of-the-art statistical mechanics. The simulations employ the polarizable water model developed recently by Dang [J. Chem. Phys. [bold 97], 2659 (1992)]. The ion--water interaction potentials are defined such that the successive binding energies for the ionic clusters, and the solvation enthalpy, bulk vertical binding energy, and structural properties of the aqueous solution agree with the best available results obtained from experiments. Simulated vertical electron binding energies of the ionic clusters Cl[sup [minus
The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.
Novel lightweight bricks have been produced by sintering mixes of dried water treatment sludge and rice husk. Samples containing up to 20 wt.% rice husk have been fired using a heating schedule that allowed effective organic burn-out. Rice husk addition increased the porosity of sintered samples and higher sintering temperatures increased compressive strengths. Materials containing 15 wt.% rice husk that were sintered at 1100 degrees C produced low bulk density and relatively high strength materials that were compliant with relevant Taiwan standards for use as lightweight bricks. PMID:19596512
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 samples prepared using similar preparation methodology. (author).
Metallic contamination was monitored with Surface Photovoltage (SPV) technique in integrated circuit manufacturing facilities. Conventionally, Czochralski silicon bulk materials were used as monitor wafers. However, it has been observed that the diffusion length and the `Iron' concentration measured with SPV were inconsistent from run to run in one facility. The inconsistency is believed to be due to oxygen precipitate in silicon materials during the thermal cycle. By using low oxygen concentration or Float Zone wafers, metallic contaminants can be monitored more accurately and consistently.
A LiF crystal analyzer has been used to measure phonon creation events when a low energy He beam scatters from a Cu(001) surface at low temperature (16 "0K). As only phonon creation events were observed, the inelastic scattering was subspecular. Atom parallel momentum gain and loss events were observed and both bulk and surface modes contributed to the inelastic scattering. An elastic component of scattering was observed over a wide angular range.
Optimum conditions for microstructural control in industrial hot working of cast and homogenized AZ31 magnesium alloys are evaluated by using a processing map. The recommended window for bulk metal working of this alloy is the domain in the temperature range 300-450 C and strain rate range 1-10 s{sup -1}, and the optimum processing parameters are 400 C and 10 s{sup -1}, where grain-boundary self diffusion is the rate-controlling mechanism. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
An interferometric technique for hard X-rays is presented. It is based on two transmission gratings and a phase-stepping technique, and it provides separate radiographs of the phase and absorption profiles of bulk samples. Tomographic reconstruction yields quantitative three-dimensional maps of the X-ray refractive index and of the attenuation coefficient, with a spatial resolution down to a few microns. The method is mechanically robust, it requires little monochromaticity, and can be scaled up to large fields of view. These are important prerequisites for use with laboratory X-ray sources. Numerous applications ranging from wave front sensing to medical radiography are presently under investigation.
Carbon nano tubes are easily produced in macroscopic quantities, however their characterisation and possible applications are still rather limited. We have developed a new method to make aligned nano tube films which open new opportunities, not only for basic research but also for eventual applications. With this method the tubes can be aligned either parallel or perpendicular to the surface. We give a short review of the microscopic properties of single tubes and the bulk properties of the aligned films. (author). 24 refs., 6 figs.
A theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements.
Flow cytogenetics is a rapidly developing technology which complements rather than supplants the traditional methods of cytogenetic analysis. As an adjunctive approach to chromosome classification, flow systems measurements of isolated chromosomes give new information relative to the enrichment of A-T or G-C base sequences on specific chromosomes. As a result, chromosomal fluorescence polymorphisms both within and among individuals that are not always associated with banding polymorphisms can be detected. Finally, flow sorting provides bulk quantities of highly purified chromosomes for use in biochemical studies. Methodology is detailed. (PSB)
Conduction-band electrons, formed by pulse radiolysis of Degussa P25 TiO_2 particles, have been monitored by time-resolved microwave conductivity and found to undergo equilibrium localization and eventual recombination at the particle surface. In the presence of isopropyl alcohol recombination is retarded due to surface hole scavenging. The particle bulk can then be pumped with mobile electrons, which survive for seconds.
The results of the study of dimensionally dependent fluorescence of boron difluoride ?-diketonates of general formula (R1COCHCOR2)BF2 are presented. The fact that for most of the compounds studied a noticeable hypsochrome shift of the luminescence band maximum is characteristic during transition from bulk crystals to microcrystals was detected. However, for boron difluoride dibenzoylmethanate having a unique supramolecular structure, a bathochromic shift of luminescence due to the crustal size reduction is observed. The dimensionally dependent luminescence properties of the complexes have been analyzed within the exciton mechanism
A considerable time can elapse between initial selection of candidate plus trees and harvest of improved seed. The technique showing the greatest promise of shortening this interval is vegetative propagation. Stock plants are grown for two years from seed before the first propagation cycle begins and each plant can be bulked-up 300-500 times over two cycles. An initial stock of 2500 superior Sitka Spruce plants can be multiplied to yield between 300,000 and 750,000 rooted cuttings for forest use within four years from the start of propagation.
The surface composition and composition near the surface and properties of high-silica zeolites of the TsVK-1 type were studied by XPES, IRS, and low-temperature adsorption of N/sub 2/. It was found that changing the sequence of operations during preparation of the H form of the zeolites results in a different set of acid centers on their surface, caused by migration of cations into the bulk of the zeolites. Migration of elements is also observed during the catalytic reaction of conversion of ethanol.
The dispersion curves E(k-bar) have been calculated for bound and resonant (110) surface states of AlSb, AlAs, and AlP. AlSb is predicted to have no surface states within the bulk fundamental band gap, but AlAs and AlP are predicted to have surface state band minima which are very near the conduction band edge, and could lie either within the gap or immediately above the edge.
Analytic expression is derived for X-ray fluorescence dependence on the particle size of powder and slurry media. The expression is obtained for a model of powder medium containing particles of different size and random distribution in the bulk of the sample. Limiting cases of homogeneous and slurry-like media are considered and expressions for calculation of the fluorescence intensity are derived. The results reasonably match the experiment for binary powder mixtures and thus provide evaluation of the powder particle size on the fluorescence intensity for multicomponent polydisperse powder medium
An integrated approach to the modelling of hydrogen assisted failure in 316L steel is presented. The approach includes experimental, fractographic, numerical and theoretical analysis of the phenomenon. The physical adequacy of the mechanical models of hydrogen embrittlement (notch extension model and notch cracking model) is discussed by comparing the virtual damage depth (theoretical) predicted by the models with the embrittled zone (microphysical) measured in the fractographic analysis by scanning electron microscopy. In addition, a numerical modelling of hydrogen diffusion is performed, concluding that bulk diffusion is not important in hydrogen embrittlement of 316L steel, so that hydrogen transport accelerated by the microdamage itself should be taken into account. (orig.)
A simple analytical model has been developed in order to provide a framework for designing experimental programs for convective loss determinations, for analyzing available experimental data from solar receiver test programs, and for estimating the convective loss at a relatively small cost. Analytical results and experimental evidence indicate that the convective loss from cavity receivers is appreciable, while the effects of wind on the convective loss under normal operating conditions are minimal. The proposed analytical model provides a means of determining the relative importance of the internal resistances and predicting the bulk air temperature within the convective zone inside the cavity.
The acoustic hyperlens can be realized by an alternating layered structure of water and fluid with negative mass density. Based on this alternating layered principle, we propose that an acoustic metamaterial consisting of three layers in water background can be designed to replace the fluid with negative mass density. The effective mass density and bulk modulus of the system which is composed of acoustic metamaterial and water are functions of the frequency. The effective mass density of such a system is close to the negative mass density of the fluid at a specific frequency; thus an acoustic metamaterial hyperlens can be achieved.
Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurobehavioral disorder affecting 5% to 10% of children. Although considered to be a highly familial disorder, ADHD heritability estimates of 60% to 80% highlight the considerable role that environmental factors may still play in disorder susceptibility. Proposed ADHD environmental risk factors include prenatal substance exposures, heavy metal and chemical exposures, nutritional factors, and lifestyle/psychosocial factors. This paper reviews the literature published in 2010 investigating the association between environmental risk factors and ADHD or related symptomatology. Sources of risk factor exposure and the proposed mechanism by which each exposure is linked to ADHD-related neurobehavioral changes are also reported. Metho...
Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal properties. In view of enhancing growth, yield and quality of this medicinally important plant, a pot experiment was conducted according to simple randomized block design. The experiment was aimed at studying the effect of four concentrations of TRIA (10?0, 10?7, 10?6 and 10?5?M) on the performance of mint with regard to growth and other physiological attributes, crop yield and quality attributes and the yield and contents of active c...
Cyst nematodes are troublesome parasites that live on, and destroy, a range of important host vegetable plants. Damage caused by the potato cyst nematode has now been reported in over 50 countries. One approach to eliminating the problem is to stimulate early hatching of the nematodes, but key hatching stimuli are not naturally available in sufficient quantities to do so. Here, we report the first chemical synthesis of solanoeclepin A, the key hatch-stimulating substance for potato cyst nematode. The crucial steps in our synthesis are an intramolecular cyclization reaction for construction of the highly strained tricyclo[5.2.1.01,6]decane skeleton (DEF ring system) and an intramolecular Diels???Alder reaction of a furan derivative for the synthesis of the ABC carbon framework. The present ...
In general, the tickover speed of a car engine is made sufficiently high, in order to permit an assumed maximum load to be taken from the engine at tickover. This setting of the tickover speed is usually done by stops in the fuel supply. Matching the actual load would lead to lower fuel consumption, without any danger of the engine stalling. The purpose of the invention is to provide a tickover speed controller, so that the tickover speed is adjusted by electronic control equipment, independently of the machine load. The fuel consumption on tickover is reduced and the emission of noxious substances is decreased. The electro-magnetic control of the throttle valve tickover setting is explained by extensive section drawings of the system. This process dispenses with the special tickover cams for a cold start.
The evolution of metallic substance atomic structure is studied on temperature variation including crystal heating up to melting points, a crystal- liquid phase transition and initiation of a high-density liquid specific structure. It is marked that heat induced changes of simple metal structure can be described as changes around a natural elementary cell which is common for both a crystal and a liquid and consists of a central atom and Z_1 atoms of the first coordination sphere. On this basis the vacancy model of melting is verified. Concentrations of melting vacancies are determined by coordination numbers in the form of Z_1/(1+Z_1)"2 which are the same for both a crystal and a natural elementary cell. The size of natural elementary cells is in an agreement with that of the coordination sphere featured in the liquid and phase transition statistical theory. Calculated data are given for a number of metals, Cs, Eu, Ni, V included
The dependence of melting temperature T m on the size and shape of an n -dimensional nanocrystal of elementary single-component substance is studied. The nanocrystal has the form of an n-dimensional parallelepiped with a square base. The ratio of the length of side rib to the length of base rib (which is equal to f) defines the form of the system. It is demonstrated that, if the surface pressure is ignored, the value of T m decreases with isomorphic (f = const) decrease in the size of nanocrystal. In so doing, the more the value of form parameter f deviates from unity, the more appreciable the size dependence of T m will be. However, if the surface pressure (?Laplace pressure??) is taken into account in the case of decrease in size, the value of T m may vary significantly. In so doing, if ...
Describes temperature and humidity sensing devices used in mine rescue operations. Chemical indicators use chemical substances that melt at predetermined temperatures and display the actual temperature in the range of 40-50 C. Electronic temperature monitoring devices release acoustic signals as soon as a temperature of 40 or 45 C has been exceeded. A more recent piece of equipment combines the ULR rescue communication set with remote temperature sensing. A digital meter that measures temperature and humidity in the range of -100 to +200 C and 3 to 98% respectively has also been developed. The Central Mine Rescue Station in Bytom, Poland has developed equipment that permits body temperature and pulse rate of a rescuer to be measured and transmitted by radio over a distance of up to 50 m. Safe threshold values can be set for each individual rescuer.
Background Previous reports in adults have suggested that the effects experienced after cannabis use can be described in terms of positive and negative subtypes that are heritable and are associated with abuse and dependence. This study extends existing research by inclusion of adolescents and young adults in an offspring of twins design which makes it possible to take into account genetic and environmental risks for substance use disorder. Methods Data were collected from 725 twin members of the Vietnam Era Twin Registry, 839 of their 12-32 year old biological offspring and 427 mothers. Offspring who had ever used cannabis (n=464) were asked the degree to which they typically experienced 13 subjective effects shortly after using cannabis. Latent class analysis (LCA) was used to derive sub...
The coastal ecosystem health assessment is a field of increasing importance. In this paper, a preliminary assessment of ecosystem health in Zhejiang coastal water zone was made, mainly based on remote sensing data and GIS technique. Its spatial and quantitative evaluation was facilitated by the progress of remote sensing and GIS technique development. Firstly, human activities, hydrology and ecosystem problems in the study area were discussed and analyzed. Secondly, from 4 aspects of human stress, physical, chemical and biological responses to anthropogenic activities and natural stress, several indicators such as water transparency (Secchi Disk Depth, SDD), suspended substance concentration, dissolved inorganic nitrogen, active phosphate, chlorophyll, harmful algae bloom, as well as distr...
The objective of this research was to convert coal into a soluble substance under mild conditions. The strategy involved two steps, first to breakdown the macromolecular network of coal, and second to add hydrogen catalytically. We investigated different basic reagents that could, in priciple, break down coal's structure and alkylation strategies that might enhance its solubility. We examined O- and C-alkylation, the importance of the strength of the base, the character of the added alkyl groups and other reaction parameters. This work provided new information concerning the way in which hydrogen bonding, polarization interactions between aromatic structures and covalent bonding could be disrupted and solubility enhanced. The objective of our research was to explore new organochromium chemistry that might be feasible for the hydrogenation of coal under mild conditions.
By methods of vibrational (infrared, Raman) and PMR spectroscopy, crystallohydrate forms of monosubstituted uranyl orthophosphate have been examined. The vibrational frequencies of the groupings from the compounds were identified. The existence of non-equivalent H_2PO_4"--groups in the substances under investigation was ascertained. It has been suggested that one of them is a bridged group, and the other is the end group. A fragment of the VO_2(H_2PO_4)_2 hydrate structure is given, its main constituents being uranylphosphate chains. The analysis of water vibrations assumes coordination of one mole of H_2O in VO_2(H_2PO_4)_2:3H_2O to uranium, while two other molecules are only hydrogen-bonded with phosphate anions. Absorption within the region of 2100-2550 cm"-"1 is assigned to vibrations of O...H...O groupings.
The human articular cartilagineous proteoglycans (PG) R.I.A. is highly specific. The PG used as the standard and the /sup 125/I labelled molecule appear to be pure. Under these conditions, all the potential interfering substances which have been tested show no cross reaction. For instance, the Ag-Ab equilibrium is not affected by adding human IgG, human albumin, hyaluronic acid, chondroitin sulfate, rat type II collagen or total human serum proteins. This R.I.A. also exhibits a species spcificity since there is no cross reaction with rat PG and negligible cross section with dog PG. The results obtained after addition of enzymes to the antigen demonstrate that the antigenic sites are localized on the protein region and not on the glycosaminoglycan region of the molecule.
Abstract Many solute carrier transporters that interact with anticancer agents and contribute to their pharmacokinetics have been shown to be differentially upregulated in cancer cells as a result of adaptive response to altered nutritional requirements. This review focuses on pathophysiological function of membrane transporters responsible for the influx of physiological substances including oligopeptides, amino acids, and organic cations and anions, and summarizes the recent knowledge regarding mechanisms in their gene expressions. Broad substrate specificity of enhanced oligopeptide H+/peptide cotransporter 1 activity in cancer cells is useful for tumor tissue-specific delivery of chemotherapeutic agents and positron emission tomography diagnostic probes. Amino acid transporters such as...
For a solar cell, in order to minimize the loss of incident light, transparent glass or plastic material is used at the incident part. When a solar cell is watched from the light incident part, a silicon base material is directly observed with either block or brown color only. This invention enables a solar cell to give brighter color on the incident surface by placing a reflective film which reflects only the light of specific wavelength, without reducing the efficiency of the solar cell. This reflective film consists of multi-layered dielectric with 12 layers and alternative combination of highly refractive and less refractive substances. Highly refractive layer is Y/sub 2/O/sub 3/ with refractive index 1.74 and the less refractive layer is SiO/sub 2/ with refractive index 1.45. (5 figs)
This remedial investigation (RI)/feasibility study (FS) supports the selection of remedial actions for the David Witherspoon, Inc. 901 Maryville Pike Site in Knoxville, Tennessee. Operations at the site, used as a recycling center, have resulted in past, present, and potential future releases of hazardous substances in to the environment. This Site is a Tennessee Superfund site. A phased approach was planned to (1) gather existing data from previous investigations managed by the Tenn. Dept. of Environment and Conservation; (2) perform a preliminary RI, including risk assessments, and an FS with existing data to identify areas where remedial action may be necessary; (3) gather additional field data to adequately define the nature and extent of risk-based contaminants that present identifiable threats to human and/or ecological receptors; and (4) develop remedial action alternatives to reduce risks to acceptable levels.
The term 'health/functional food' (HFF) refers to food supplements containing nutrients or other substances (in a concentrated form) that have a nutritional or physiological effect whose purpose is to supplement the normal diet. The Korean Health/Functional Food Act that came into effect in 2004 requires these products to be marketed in measured doses, such as in pills, tablets, capsules, and liquids. HFFs are of two types: generic and product-specific. There are 37 ingredients listed in the act for generic HFFs, and if an HFF contains a new active ingredient that is not included in the generic 37 products, it is considered a product-specific HFF. The standardization, safety, and efficacy of a new active ingredient are reviewed by the Korean Food and Drug Administration in order to receive approval as a product-specific HFF. Conforming with international standards and protecting public health requires constant upgrading of the Health/Functional Food Act.
Real-time neutron radiography (RTNR) is now proving to be a valuable research tool in the study of hydrogenous fluid flow. One of the most significant advantages of neutron radiography is the ability to image hydrogenous substances (such as lubricants, coolants, and fuels) inside metallic materials such as aluminum and titanium engines. By using RTNR, one can then study dynamic events such as the movement of liquids inside these solids. The Phoenix Memorial Laboratory (PML) at the University of Michigan has recently developed and installed a facility dedicated to RTNR. The work at PML has shown that RTNR of dynamic events can provide information enabling the researcher to follow dynamic events that were previously impossible or impractical. This paper will show the variety of uses of RTNR presently being pursued at PML.
Real-time neutron radiography (RTNR) is now proving to be a valuable research tool in the study of hydrogenous fluid flow. One of the most significant advantages of neutron radiography is the ability to image hydrogenous substances (such as lubricants, coolants, and fuels) inside metallic materials such as aluminum and titanium engines. By using RTNR, one can then study dynamic events such as the movement of liquids inside these solids. The Phoenix Memorial Laboratory (PML) at the University of Michigan has recently developed and installed a facility dedicated to RTNR. The work at PML has shown that RTNR of dynamic events can provide information enabling the researcher to follow dynamic events that were previously impossible or impractical. This paper will show the variety of uses of RTNR presently being pursued at PML.
The design of a reaction cell which permits the investigation of the sorption kinetics of microcomponents without separation of the phases under automated condition has been described. The use of thin-layer inorganic sorbents obtained by depositing films of a sorbing substance from aqueous solutions on flat substrates of small thickness makes it possible to determine the extent of sorption even at small values in the case of /beta/ emitters with a low energy and /alpha/ emitters. Detailed observation of the kinetics of isotopic exchange in the CdS-/sup 115m/Cd-HNO/sub 3/ system has made it possible to reveal at least four stages in the process during the time of observation.
The rate was studied of radiation destruction of phenol aqueous solutions at a concentration range of 1 to 100 ppm. Irradiated were model solutions containing additions of some organic and inorganic substances typical of the petrochemical industry. In view of the fact that the radiation destruction kinetics is determined by the amount of dissolved oxygen in the sample and by the phenol concentration, relatively low doses were used. Thus, a sufficient amount of oxygen in the sample and therefore the oxidation mechanism of radiolysis were ensured. The dose-response relationships for phenol destruction were studied using doses of 50, 100, 200 and 400 J.kg"-"1; the limit dose was 500 J.kg"-"1. From the results obtained, a kinetic model was constructed of radiation phenol oxidation in aqueous solutions in the presence of various organic and inorganic additions. (B.S.).
The noncrystalline compounds MoS_3, WS_3 and MoSe_3 were studied by X-ray diffraction. From the diffuse intensities radial distribution functions were computed and interpreted in terms of pair distribution functions. The substances are built up by microcrystallites which contain three metal atoms and are bridged statistically to each another. The shortest metal chalcogen distances d(MoS) approximately d(WS) = 2.40 +- 0.05 A and d(MoSe) = 2.50 +- 0.05 A are significantly longer than in MS- or MSe compounds with a d"0 configuration of the metal respectively and metal-metal distances within the microcrystallites are less than 3 A. (author).
In order to describe quantum heat engines, here we systematically study isothermal and isochoric processes for quantum thermodynamic cycles. Based on these results the quantum versions of both the Carnot heat engine and the Otto heat engine are defined without ambiguities. We also study the properties of quantum Carnot and Otto heat engines in comparison with their classical counterparts. Relations and mappings between these two quantum heat engines are also investigated by considering their respective quantum thermodynamic processes. In addition, we discuss the role of Maxwell's demon in quantum thermodynamic cycles. We find that there is no violation of the second law, even in the existence of such a demon, when the demon is included correctly as part of the working substance of the heat engine.
An inorganic particulate adsorbent of a titania-alumina is described for treating a superheated water containing radioactive materials such as cobalt ions, which is free from release of corrosive impruities, and which has a high adsorption capacity of radioactive materials and a high mechanical strength is prepared by hydrolyzing a titanium alkoxide and an aluminum alkoxide, thereby forming a hydrous titanium oxide and a hydrous aluminum oxide, respectively; precalcining the hydrous titanium oxide and aluminum oxide, mixing and molding the resulting titania and alumina into a particulate mixture thereof having a titania mole fraction of 0.2 to 0.9, and calcining the particulate mixture at 500/sup 0/-700/sup 0/C. This absorbent is effectively used in treat boiling water-type nuclear reactor core-circulating water to remove radioactive substances therefrom.
The dependence of the inhibiting action of some surface active organic substances (SAOS) on the pitting- formation potential epsilonsub(p) has been investigated for the steel Kh25T. The study has been performed by potentiostatic method using the H_2SO_4 0.1-n-solution doped by NaCl, Na_2SO_4, in the presence of SAOS of different classes. As epsilonsub(p) shifts in positive direction from +0.6 to +1.1 V, the inhibiting action of the SAOS series (o-oxyquinoline) increases gradually till some critical potential above which SAOS favour pitting destruction of steel. This phenomenon should be considered in anodic protection in SAOS-doped solutions.
Part of the crushed activated charcoal (about 20-50%) designed for manufacture of electrodes is made water repellant with the help of an aqueous suspension of water repelling agent containing 3-15% (preferably 10%) dry substance. After this the remaining part of the activated charcoal and the other additives are mixed with the water repelling part. The plates or tape which is rolled to an assigned thickness are pressed from the obtained mixture. The electrodes obtained by this method have a thin active layer and a porous structure and have good diffusion properties. They can be loaded by currents up to 80 mA/cm/sup 2/ without causing excessive polarization losses, and their service life is greater than or equal to 100 h.
The measurement of level in the liquid nitrogen vessel has been carried out by the weight conversion method using weigher or by putting directly a stick in the vessel. On a large CE tank, the pressure difference was read by manometer. These methods can not be used when the vessel does not put on the weigher or the pipe for manometer is stopped. We noticed the interaction between radiation ({gamma}-ray) and substance and applied it to determine the liquid nitrogen level. The results proved it the easy method for measurement of the level in the large CE tank. Cesium 137 ({gamma}-ray energy: 662 keV) was used as the radiation source. {gamma}-ray transmission dose was determined by GM survey meter. The liquid nitrogen level could be determined by using the change of the transmission dose with amount of liquid nitrogen. (S.Y.)
Magnetic resonance imaging has proven an invaluable method in the diagnosis of joint diseases associated with osteonecrotic, inflammatory, traumatic and degenerative processes. At the clinical level, it has an important role in decisions about the method of treatment and evaluations of the therapeutic success. When the merits of MRT are balanced against those of conventional radiography including tomography and CT, which both ensure better spatial resolution in the visualisation of cortical and spongy bone structures, it becomes quite evident that MRT must not be regarded as an alternative method of imaging but as one that can be used additionally to obtain the most information for the diagnosis of arthropathy. The question as to whether new pulse sequences (snap shots) or invasive techniques like intra-articular injection of paramagnetic substances (MR arthrography) are likely to become routine procedures in the detection of joint diseases using MRT remains to be ...
The article profiles developments in pollution control resulting from the strict emissions control standards due to be set by the European Commission in 1992. In particular technology to meet new emissions targets for mercury and dioxins is described. Control technologies covered included fixed-bed, direct injection, circulating fluidized bed and spray adsorption all of which use activated charcoal to absorb dioxin and mercury. Unfortunately activated charcoal processes still leave waste to be disposed of. Options include recycling the spent activated charcoal to the incinerator, vitrifying the activated charcoal and fly ash into a glassy unleachable substance and cracking the dioxins catalytically. It is hoped the developments will increase public acceptance of incineration. 4 figs., 1 tabs.
The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can b...
A study was made of employee exposure to oil sludge and vapors during oil-sludge removal and maintenance activities at the Alyeska Pipeline Service Company's Ballast Water Treatment Facility, Valdez, Alaska. Total hydrocarbons, except benzene, toluene, and xylene, showed concentrations from 371 to 1228mg/m3. Of eight maintenance workers, five reported headache, dizziness, or nausea when working without a respirator. The authors conclude that workers were potentially exposed to benzene vapors and total hydrocarbon vapors exceeding the evaluation criteria for these substances. The authors recommend the use of respiratory protection measures to reduce exposures during work operations.
The mission of the Health and Safety Research Division (HASRD) is to provide a sound scientific basis for the measurement and assessment of human health impacts of radiological and chemical substances. Our approach to fulfilling this mission is to conduct a broad program of experimental, theoretical, and field research based on a strong foundation of fundamental physical studies that blend into well-established programs in life sciences. Topics include biomedical screening techniques, biological and chemical sensors, risk assessment, health hazards, dosimetry, nuclear medicine, environmental pollution monitoring, electron-molecule interactions, interphase physics, surface physics, data base management, environmental mutagens, carcinogens, and tetratogens.
The Hanford Waste Vitrification Plant Project has been established to convert the high-level radioactive waste associated with nuclear defense production at the Hanford Site into a waste form suitable for disposal in a deep geologic repository. The Hanford Waste Vitrification Plant will mix processed radioactive waste with borosilicate material, then heat the mixture to its melting point (vitrification) to forin a glass-like substance that traps the radionuclides in the glass matrix upon cooling. The Hanford Waste Vitrification Plant Quality Assurance Program has been established to support the mission of the Hanford Waste Vitrification Plant. This Quality Assurance Program Description has been written to document the Hanford Waste Vitrification Plant Quality Assurance Program.
The erosion of rocks rich in organic matter typically leads to the complete mineralization of the organic material. However, in some cases, it is re-deposited to become a part of sediments once more. This process should be considered to be a part of global carbon cycle, possibly much more significant than assumed to-date. The research presented here aims to characterize re-worked organic matter occurring in post-glacial sediments of southern part of Poland, in the Oder river valley (the Racib?rz town region, Miocene, Pleistocene and Holocene age). Organic substances extracted from the sediments originated from organic matter that had resided in rocks eroded by glaciers. Sediments were sampled in two boreholes which sediments were correlated. Sediments were extracted and extracts analyzed w...
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.
The solubility behavior of solid residues from the heat treatment of domestic rubbish was examined by simulated precipitation in laboratory lysimeters. The precipitation corresponded to the average amount of rain in West Germany and was applied at different time periods. Specific soil characteristics, the value of k/sub f/ and the water retention capacity was determined in this way. In parallel with the lysimeter flood ions, extraction (by batch process) was done, in order to find the maximum solubility of the materials used. It was found that for pyrolysis residues from reactor temperatures of 450/sup 0/ to 1000/sup 0/C, a greater solubility was measured than for slag from combustion. The eluates from these residues gave information about the degree of contamination or on the solubility of the measured parameters and materials in organoleptic, physical, organic and inorganic examinations. The concentrations of harmful substances in the eluates pointed to the ...
BACKGROUND: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water-dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites. The fruit samples gained from the field trials were quantitatively analysed by gas chromatography with a nitrogen phosphorus detector (GC/NPD) for tebuconazole residues. RESULTS: Tebuconazole ...
The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.
Sulfur pollution can lead to serious problems in freshwater wetlands, including phosphorus eutrophication and sulfide toxicity. We tested the effects of anaerobic iron-rich groundwater discharge in fens, simulated by iron injection, on two characteristic species (Juncus effusus and Caltha palustris) in a sulfidic environment. Biomass production of C. palustris roots showed an optimum response to the combined addition of iron and sulfide, with highest values at intermediate concentrations of both substances. Iron deficiency apparently occurred at low iron concentrations, while at high iron concentrations, growth was decreased. For J. effusus, in contrast, no toxic effects were found of both iron and sulfide. This could be explained by larger radial oxygen loss (ROL) of J. effusus and could ...
In evaluating the risk associated with low levels of exposure to toxicants, it is clear that DNA repair, one of the main defenses against agent damage, is not a constant. It can be modified by age, time of day, and physiological state. Nutrition, especially caloric restriction (CR), can modify almost every step in the process of protecting genomic integrity. And history of exposure can modify DNA repair. Thus, the conditions of exposure are almost as important to toxicity as the exposure itself, even at the level of DNA repair. Extrapolation from high to low dose, to be consistent with what is known, should be less a mathematical exercise than an exercise in toxicological judgement, which puts the exposure in proper perspective. This appears to be true at almost every level in the process including a response with a toxic stimulus, even those thought to be very basic, such as DNA repair.
The adhesion of microorganisms onto materials surface mediated by extracellular polymeric substances (EPS) lead to an important modification of the metal-solution interface. The requirement of modern civilization with the heightened sense of environmental responsibilities and quality of life can be met by using some eco-friendly microbiocides with different spectra of activity. Some N{sub 2}O{sub 2} donor Schiff base compounds were synthesized and characterized by IR, NMR and ESR spectroscopy. These compounds were found effective in controlling the growth of biofilm of E. coli, Pseudomonas fluorescens and Thiobacillus thiooxidans on copper surface. The optimum concentration of these compounds are in the range of 1--10 ppm. Various electrochemical, microbiological and surface-analytical techniques were used to monitor the biofilm in the presence of microbiocides.
During 1978 the Engineering Board of SRC granted Specially Promoted Program status to the Coal Technology program. This recognized that coal would increase in importance as the cost of liquid and gaseous hydrocarbons rises with the decreasing availability of petroleum related sources. It was, therefore, considered necessary to anticipate and improve, through SRC supported research, the technologies required to win, transport, convert to liquid and gaseous fuels and utilize coal and coal based substances. In view of the interest in the program, and also in the hope of reaching a still wider audience the reports of the two meetings have been combined in this single booklet. The reports indicate specific problems of importance in coal winning and coal conversion but, naturally, do not cover all of the program priorities.
The emission of air pollutants from road vehicles is the most significant source of air pollution in towns. The chemical composition of these pollutive substances is dependent on the fuel, the type of vehicle and the character of the traffic system. The pollution concentration was measured, (nitrogen oxides and carbon monoxide) in relation to each type of vehicle, in four streets in the Copenhagen area. The system of measurement used was the ''Operational Street Pollution Model'' (OSPM). Results are presented in the form of tables and charts. (AB) 11 refs.
Varroa destructor is an ectoparasitic mite that affects colonies of honey bee Apis mellifera worldwide. In the last years, substances of botanical origin have emerged as natural alternative acaricides to diminish the population levels of the mite. In the present work, the bioactivity of propolis from different geographical locations of Pampean region from Argentina on V. destructor was evaluated. Fourteen propolis samples were organoleptic and physicochemically characterized and, by means topical applications, their activity was tested on mites. All propolis had a homogeneous composition and the bioactivity levels against mites were comparable among the different propolis samples. The percentage of mites killed by the treatments ranged between 60.5% and 90% after 30?s of exposure. Thus, V....
The feasibility of this procedure was investigated using minerals and ore specimens. The substances were ground then fused using LiBO/sub 2/, quenched with 3% HNO/sub 3/ or mixtures of the acid with 2.5% tartaric acid or 30% H/sub 2/O/sub 2/. The quenched melt was usually completely dissolved within 20 min by placing the beakers in an ultrasonic bath. If any residue was detected, appropriate changes were made in the procedure. Once the procedure has been optimized, any remaining black particles were filtered. If these particles disappeared upon subsequent ignition, they were presumed to have been graphite. Most of the refractory minerals investigated should be expected to be converted to soluble form by this process. 1 table.
The problems are discussed of using radionuclide X-ray fluorescence analysis (the most frequently used source is "2"4"1Am) and neutron activation analysis for monitoring the chemical quality of the working environment of a welder. Elements determinable by these methods are listed and the advantages of the methods stated with regard to speed, simplicity and appropriate accuracy of measurement together with commercial availability of the instruments. Welding as a source of harmful substances is assessed by determination of the amount of chromium in aerosols generated by welding austenitic chromium-nickel steels. The described methods allow to obtain a complex image of the chemical nature of welding aerosols and to understand the mechanism of their impact on the human organism. (J.C.).
Banana (Musa acuminata Colla AAA) peel extracts obtained in this work had a high capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2prime-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS+) free radicals, and they were also good lipid peroxidation inhibitors. Acetone:water extracts were considerably more effective (compared with methanol, ethanol, acetone, water, methanol:water or ethanol:water) at inhibiting the peroxidation of lipids in the b-carotene/linoleic acid system or scavenging free radicals. However, aqueous extracts had a high capacity to protect lipids from oxidation in the thiobarbituric acid reactive substances (TBARS) test, as well as in the b-carotene bleaching assay. In addition, acetone:water most efficiently extracted all extractable components (54+-...
Objectives1. To establish the present capacity and capability across all the sectors within the UK for - a) Undertaking research in the areas of toxicology and ecotoxicology and environmental hazard and risk assessment work on chemical subtances including emerging containments (e.g. enginerred nanomaterials); and b) Applying these skills in the policy and regulatory context. 2) The range of chemicals involved should include pharmaceutical and medical products, crop protection agents, biocides, vet [continued...]DescriptionThe aim of this project is to identify the current status of the scientific community, areas of expertise, and identify the gaps in skills, knowledge or recruitment. The project will use a questionnaire approach to obtain this information for all sectors of the business community. The analysis will identify the gaps in provision, and areas where investment is needed in future training and/or recruitment.
Eight culture-collection yeast strains of various species and five newly isolated stains were tested for both growth in olive oil extraction effluents and fermentation of the sugars in the same media. The culture-collection yeast strains did not grow in an effluent containing 2.86% sugar (w/v), 8 g/litre phenolic substances, 4.58 g/litre titratable acidity and pH 4.96, whereas the newly isolated strains of Torulopsis sp. MK-1, Saccharomyces norbensis MC-1, S. oleaceus MC-2 and S. oleaginosus grew well and fermented the sugars. In the medium mentioned above, they produced alcohol in amounts of 1.63 to 1.38%, respectively. None of the yeasts grew in an olive oil extraction effluent vacuum-concentrated to over 13-14% of dry matter. The strain of T. sp. MK-1 showed a higher stability.
Abstract The inhibitory effect of the extract from Magnolia officinalis (MOE) against L. monocytogenes, S. faecalis, E. coli, S. typhimurium, S. aureus and B. anthracis by paper-diffusion methods and the characterization of the mutton immersed in different concentrations of the MOE during storage were evaluated in this paper. The results showed that MOE could significantly inhibit the growth of S. aureus, S. faecalis, B. anthracis and E. coli, and their MIC was 0.02-mg/mL, 0.03-mg/mL, 0.05-mg/mL and 0.10-mg/mL, respectively. MOE showed weak inhibition for the S. typhimurium. The mutton treated with 2%, 4% and 6% MOE resulted in suppression in the increase of total volatile base nitrogen, thiobarbituric acid reactive substance, and the growth of Enterobacteriaceae, Pseudomonas. The cooled m...
The authors have studied the distribution of H-3 labelled schistosomicidal drug in mice by autoradiography. The H-3-labelled substances were found in liver and kidney and in successfully decreasing amounts in brain, lung, heart, fat, testis, pancreas and spleen. In various cells the silver granules were present mainly in the cytoplasms but a few in the nucleus. After administration of this labelled schistosomicidal drug, the mice were killed and studied in groups successively at 4, 8, 24 hrs. No difference in the distribution of silver granules were observed. This fact indicated that, this drug was rapidly absorbed and highly concentrated with a long duration of reservation in liver. All of these favours the schistosomicidal effect of the drug. As this drug was highly concentrated in the cytoplasm of liver cells, that might provide a pathophysiologic basis for the explanation of jaundice in the clinical practice. Moreover, the appearance of toxic reaction in ...
L'invention concerne un procede de triage de cristaux irradies. Ce procede non destructeur comporte l'irradiation des cristaux par un rayonnement ionisant pendant une duree et avec une intensite telles qu'il se forme des centres colores distinctifs dans les matieres contenant des ions aluminium. Les cristaux colores qui correspondent en teinte et en profondeur de couleur a des teneurs en aluminium en dehors de la teneur desiree peuvent etre separes. On peut isoler ainsi des matieres de quartz, de verre, de silicates exemptes d'aluminium dans un melange, ou bien on peut choisir des fractions de ces matieres, chacune contenant une teneur uniforme en aluminium.
Research highlights: {yields} The use of resonant photoemission in its 'core-hole clock' expression for the study of the dynamical charge transfer across hybrid organic-inorganic interfaces and for the intermolecular charge transfer in the bulk of organic thin films is reviewed. {yields} The electronic coupling to the substrate and the efficiency of charge transport across hybrid interfaces is different for individual electronic subsystems of the molecular adsorbate. {yields} The intermolecular charge transfer in the bulk of discotic liquid crystals occurs on the order of a few femtoseconds and is faster than expected from the macroscopic charge transport characteristics of the material. -- Abstract: The focus of this brief review is the use of resonant photoemission in its 'core-hole clock' expression for the study of two important problems relevant for the field of organic electronics: the dynamical charge ...
We studied the strain introduced in a Si(111) substrate due to MeV ion implantation using extremely asymmetric x-ray diffraction and measured the rocking curves of asymmetrical 113 diffraction for the Si substrates implanted with a 1.5 MeV Au"2"+ ion at fluence values of 1x10"1"3, 5x10"1"3, and 1x10"1"4/cm"2. The measured curves consisted of a bulk peak and accompanying subpeak with an interference fringe. The positional relationship of the bulk peak to the subpeak and the intensity variation of those peaks with respect to the wavelengths of the x rays indicated that crystal lattices near the surface were strained; the lattice spacing of surface normal (111) planes near the surface was larger than that of the bulk. Detailed strain profiles along the depth direction were successfully estimated using a curve-fitting method based on Darwin's dynamical diffraction theory. Comparing the shapes of resultant strain profiles, we ...
Neutron reflectometry (NR) was used to measure the concentration profile of a symmetric PEP/dPEP polymer blend with nanometer-scale resolution in the one-phase region. The shape of the profile near the surface was found to differ significantly from mean-field theory predictions for all bulk concentrations and temperatures surveyed. The profile shape is flattened at the surface over a distance about half the bulk correlation length, a length scale far greater than that of the dispersive forces that are the dominant microscopic interaction in such blends. We introduce a new method for extracting the surface energy difference that drives segregation based on the Gibbs adsorption equation (GAE) and compare it to a previous method based on mean-field theory. While both methods produce qualitatively similar results (the surface energy of pure dPEP is {approx}0.21 mJ/m{sup 2} smaller than pure PEP), the GAE method is much less model dependent, ...
Results of self-consistent local-spin-density-functional calculations are reported for the first time for the Ni(110) surface, represented by one-, three-, and five-layer slabs. Calculations for one- and five-layer slabs of Ni(100) are also reported. The behavior of the surface magnetization with varying slab thickness elucidates the nature and origin of the surface magnetic moment. We predict a 13% enhancement of the Ni(110) surface magnetic moment compared to the bulk value. For the Ni(100) surface, we find a smaller surface enhancement about 7%, compared to bulk, which agrees with the results of Jepsen et al. The enhancement of surface magnetic moments on Ni(100) and Ni(110) surfaces is attributed to s-d dehybridization at the surface and to the presence of electrostatic shifts required to maintain layer-by-layer charge neutrality. We find that the total d-electron charge is the same in each layer, which contradicts the sp-to-d charge ...
Full text: Hybrid functionals, containing a fraction of the exact exchange, allow for a rather accurate treatment of e.g. small molecules and band gaps in bulk materials. A plane-wave based algorithm was implemented in VASP (Vienna Ab-initio Simulation Package) to accomplish the calculation of the exact exchange. Two functionals including exact exchange are presently available, i.e. the PBE0 (Perdew-BurKEX-Ernzerhof) and the HSE (Heyd-Scuseria-Ernzerhof). A rigorous assessment of the implementation was performed by geometry optimization and calculation of the atomization energies of the G2-1 quantum chemical test set, containing 55 molecules. Excellent agreement compared to corresponding Gaussian 03 data and good agreement with experiment was achieved. The mean absolute error (theory related to experiment) for the atomization energies calculated with the PBE and the PBE0 is 8.6 and 3.7 kcal/mol, respectively. To investigate the properties of ...
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 (optionally by circulating a liquid), impinger bottles and a backup adsorber. Module 4 is a volume-sampling module consisting of a pump, a ...
This report investigates methods to utilize existing bulk tobacco kilns for curing (drying) of shelled corn, peanuts, and baled hay. In recent years Ontario tobacco producers have had to reduce production levels due to a declining demand for flue-cured tobacco. Many tobacco producers are currently diversifying into other crops. Some of these crops require curing and/or storage. Because of high capital costs to purchase conventional curing and/or storage facilities, tobacco producers wish to reduce their initial diversification costs by modifying their existing tobacco kilns (tobacco drying structures) and/or tobacco storage barns for this purpose. The investigation included high profile and low profile downdraft stick kilns, bulk kilns, and tobacco storage (pack) barns. Corn, peanuts, and hay were considered in relation to bulk kiln specifications and modifications, handling, drying and storage methods, energy requirements, ...
The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River near Aiken, South Carolina. During operations, which started in 1951, hazardous substances (chemicals and radionuclides) were released to the environment. The releases occurred as a result of inadvertent spills and waste disposal in unlined pits and basins which was common practice before environmental regulations existed. The hazardous substances have migrated to the vadose zone and groundwater in many areas of the SRS, resulting in 515 waste units that are required by environmental regulations, to undergo characterization and, if needed, remediation. In the initial years of the SRS environmental cleanup program (early 1990's), the focus was to use common technologies (such as pump and treat, air stripping, excavation and removal) that actively and tangibly removed contamination. Exclusive use of these ...
Investigations and studies are conducted seeking for a CO2 fixation method improved by utilizing the photosynthesizing function of higher vegetation. Details of higher vegetation genes are being disclosed thanks to the rapid progress of studies making use of molecular biological techniques, and the application of the genetic mechanism to scientific and technological fields is becoming increasingly feasible. In particular, the role of the CO2 fixation enzyme RuBisCO has been elucidated almost completely. It has been learned that, in terms of photosynthesizing capability, the C{sub 4} plants (corn etc.) are 2-3 times higher than the C{sub 3} plants (rice, wheat, etc.), and 5-10 times higher than the CAM plants (cactuses etc.). Studies are also under way about the rice genome so that a photosynthesizing capability so high as that of the C{sub 4} plants may be endowed the rice plant. The metabolism and control of useful substances produced in the CO2 fixation process ...
The invention concerns a method for the graduated introduction of finely-particulate and especially pulverously-particulate solid substance, in particular coal dust, from a pressurised proportioning tank containing a supply of solid matter into an industrial furnace with several supply points, in particular a shaft furnace such as a blast furnace or a cupola furnace, the solid matter being conveyed to the individual supply points in a flow of carrier gas heavily charged with solid matter, through a separate transport line for each supply point, the carrier gas being conveyed to the lower end section of the proportioning tank in a current which causes a local loosening in the lower section of the supply of solid matter, with the transport lines opening into the loosened area, whilst the proportioning tank that contains the solid matter is weighed continuously, the actual weight of the proportioning tank being compared with the latter's target weight, the ...
This thesis surveys the concepts of exergy and extends the exergy method of analysis from the standpoint of its applications to the power plant systems. After a brief historical review of exergy concepts, the general exergy equation is derived from the combined equation of First and Second Law, and it is shown that any special case of exergy equation is a simplified form of the general exergy equation. The mathematical method for the exergy analysis of a steady-state, steady-flow system, analogous to that of the First Law, is given. The exergy losses in a power plant are discussed. Then in order to examine these losses, the Second Law performance of major processes of combustion, compression, heat transfer, mixing and throttling have been analyzed analytically, and the exergy efficiencies are defined that accurately assess the thermodynamic performance of the corresponding processes. The methods for computation of exergy loss and exergy efficiency are given and simplified for practical ...
Abstract in english The aim of the present study was to assess the analgesic activity of the aerial parts of two Hypericum species native to Southern Brazil, H. caprifoliatum and H. polyanthemum. The antinociceptive effect of the H. polyanthemum cyclohexane extract (POL; 180 mg/kg) and of the H. caprifoliatum methanol (MET) and cyclohexane (CH) extracts (90 mg/kg) was evaluated in the hot-plate (ip and po) and writhing (po) tests using male Swiss CF1 mice weighing 22-27 g (N = 10 per group). (more) All extracts displayed antinociceptive effects in the hot-plate test (MET ip = 48%, MET po = 39%, CH ip = 27%, CH po = 50%, POL ip = 74%, and POL po = 49% compared to control). Pretreatment with naloxone (2.5 mg/kg, sc) abolished the effects of CH and POL, and partially prevented the analgesia induced by MET administered by the ip (but not by the po) route. POL and CH (po) significantly reduced the number of writhes induced by acetic acid, while MET was ineffective in this regard. We ...
(Cu_4_7Zr_1_1Ti_3_4Ni_8)_1_0_0_-_xMo _x bulk metallic glasses (BMGs) with x = 0, 1 and 2 at.% and a bulk metallic glass matrix composite with x = 5 at.% were successfully prepared by water-cooled copper mold casting. The effect of the addition of a small amount of Mo on the glass forming ability (GFA), thermal properties of the base alloy (i.e. x = 0) were investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analyzer (DTA). It is found that the addition of appropriate amount of Mo can enhance the GFA of the Cu-based BMG, as indicated by the increase in the reduced glass transition temperature T _r_g (=T _g/T _l) and the parameter #gamma# (=T _x/(T _g + T _l)) with the increase of Mo. On the other hand, the corrosion resistance of the Cu-based BMGs with different Mo contents was examined by electrochemical polarization and weight loss measurement in 1 mol/L H_2SO_4 and 1 mol/L NaOH solutions, ...
Nitrate microelectrodes and ORP microelectrodes were fabricated to study the denitrification characteristics of dynamic membrane at different COD loadings. The denitrification process was found at 0.6-1 mm depth beneath the interface of biofilm/bulk. The results of ORP microelectrode also demonstrated that the ORP value in the range of denitrification area was between 88.6 approximately -128.4 mV which was appropriate to denitrification. When the COD loading was 0.45 kg/(m3 x d), the denitrification rate (NO3- -N) was the maximum of 0.6347 x 10(-6 mol/(L x s). With the increase of COD loading, the denitrification area was increasing and two layers with different denitrification rates emerged in the dynamic membrane. The phenomenon implied the effect of organic concentration, oxygen concentration and bacterial competition on the denitrification rate. PMID:17117632
Sphere-forming abilities in culture condition are considered a hallmark of cancer stem-like cells, which represents tumor cell invasiveness and stem-like characteristics. We aimed to show that the sphere-forming subpopulation of human malignant melanoma cell line WM-266-4 acts differently to zebrafish embryo extracts compared with their bulk counterpart. Spheres were maintained in neural stem cell culture conditions. The embryos of zebrafish at specific developmental stages were collected and the extracts were purified under 100 kDa. Spheres were treated with embyo extracts and proliferation assay and immunocytochemistry were conducted. Spheroid cells expressed nestin and epidermal growth factor receptor (EGFR) but not melanoma antigen recognized by T-cells (MART)1, indicating their stem-l...
Turbulent flow in a 2D channel with repeated rectangular rib roughness was numerically simulated using a low Reynolds number form of the k-epsilon turbulence model. Friction factors and average Stanton numbers were calculated for various pitch to rib height ratios and bulk Reynolds numbers. Comparisons with experiment were generally adequate, with the predictions of friction superior to those for heat transfer. The effect of variable properties for channel flow was investigated, and the results showed a greater effect for friction than for heat transfer. Comparison with experiment yielded no clear conclusions. The turbulence model was also validated for a related problem, that of flow downstream of an abrupt pipe expansion.
By means of ab-initio electronic structure calculation and one-dimensional Boltzmann transport equation solution, we investigate the size dependent thermoelectric (TE) properties of n-type ZnO nanowires (NWs) and surface passivation effects. As demonstrated by our calculations, largest figure of merit ZT achievable in thin NWs is larger than that in wide NWs, whereas being restrained by higher demand of n-type doping. Moreover, bare NWs are superior in TE application comparing with the passivated. To compete with conventional TE materials, lattice thermal conductivity of ZnO NWs should be at least 2 orders of magnitude lower than bulk value.
The General Electric Test Reactor emergency cooling system performance was tested by intentionally scramming the reactor and then terminating the power to the primary pump. Certain transient thermal-hydraulic data were obtained preceding and during the established natural convection cooling loop composed of the upward flow through the core and the downward flow through the pool. An analysis was performed to permit the data to be extrapolated to obtain distributed fuel element flow rates and bulk temperature rises during the established cooling loop. The earliest time for the quasi-steady natural cooling loop to develop is about 2.5 min following scram. The cladding hot-spot temperature does not exceed the local saturation temperature after quasi-steady flow is established. Data are presented to assist in the modeling of the GETR natural convection loop. Semi-empirical relationships for friction factor and Nusselt number are also presented.
Comparative patterns of equilibrium adsorption of argon on the surface of graphitized thermal carbon black (GCB) and the inhomogeneous surfaces of nongraphitized carbon black and silica at 77 and 87.3 K were considered. It was shown that argon acquires the properties of a special phase with a layered structure and exhibits two-dimensional phase transitions with the formation of crystal-like layers near the homogeneous surface of GCB even at a temperature exceeding the triple point. However, already at a distance of three-four molecular diameters from the surface, adsorbed argon behaves as a bulk phase in a weak external field. The defect surface of nongraphitized carbon black and the amorphous surface structure of silica destroy the longrange order of adsorbed argon and lower its solidific...
High-resolution observations are presented of the 300-kpc jet in the giant radio galaxy NGC 6251. The width of the jet is resolved over most of its length, and the axis of the jet wiggles with an amplitude increasing linearly with distance from the nucleus. Polarization data are used to derive densities of cold matter in the jet and, from the argument that the jet must form the lobe in a time equal to the age of the lobe, the speed of the jet is estimated as c/20. The energetics of the jet are then dominated by the bulk flow along it of cold matter at a rate of 1 solar mass yr"-"1. The jet appears to be confined; the wiggle of its axis is probably due to oscillations of the direction of the collimator with a period of about 6 x 10"6 yr. (author).
The uncertainty of the elemental analysis is one of the major factors governing the utility of on-line Prompt Gamma Neutron Activation Analysis (PGNAA) in the blending and sorting of bulk materials. In this paper, a general method applicable to Gamma spectra processing is presented and applied to PGNAA in mineral industry. Based on the Fourier transform of spectra and their de-correlation in the Fourier space (the improvement of the conditioning of the correlation matrix), processing of overlapping of characteristic peaks minimizes the propagation of random errors, which optimizes the accuracy and decreases the detection limits of elemental analyses. In comparison with classical methods based on the linear combinations of relevant regions of spectra the improvement may be considerable, especially when several elements are interfering. The method is applied to four case stories covering both borehole logging and on-line analysis on conveyor belt of raw materials.
A theory for the mass transfer process was developed. It was assumed that the largest convective motions in the flow control the rate of mass transfer. Measurements of mass transfer coefficients for the absorption of oxygen by water films were made for concurrent flows in a horizontal rectangular channel, and for concurrent and free-falling downflow in a one-inch pipe. The measured values of the Sherwood number for concurrent flows were up to three times as great as would be predicted from this relation. This increase in Sherwood number was correlated with a dimensionless group similar to a Martinelli parameter which is characteristic of two phase flows. An explanation for this effect is given in terms of the way that the scales of the convective motions are related to bulk flow parameters.
In previous work, on cooling from 300 K to 10 K the elastic moduli for both #alpha#- and #delta#-Pu dropped 30%. This large change may reflect effects of 5f-electron localization. In this work, the elastic moduli at ambient temperature of several Pu-Ga alloys were measured using resonant ultrasound spectroscopy (RUS). The strong temperature dependence of the bulk and shear modulus and the temperature independence of Poisson's ratio was confirmed and the upper temperature limit for #alpha#-Pu was extended to 360 K. Measurements of the time dependence of the shear moduli of Pu and Pu-2.36 at.% Ga were determined with high precision as a function of time and temperature. Using a model for time dependence of point defects, we determined the exponential time constant at ambient temperature for such variations. The low temperature results are consistent with Fluss .
The main goal of this research is to delineate the wetting behavior of coal and it subsequent effects on fine coal processing. As both bulk and surface properties of coal are interrelated and have a controlling role on the performance of these processes, a detailed study has been undertaken to correlate their influence on both wetting behavior and the response of coal to flotation and other unit operations encountered in fine coal processing. During the last quarter, the effect of coal rank on water retention capacity was investigated. The effect of pH on the vacuum flotation yield and the effect of desliming on the film flotation response of coal were also studied. 6 refs., 5 figs.
Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of nitride former. (orig.)
Reflectometric methods like polarised neutron reflectometry (PNR) and synchrotron Moessbauer reflectometry (SMR) are capable of investigating the plane-perpendicular and lateral magnetic structure of multilayers (MLs). Previously, a variety of domain formation and transformation phenomena was found and systematically studied in a Fe/Cr ML of strong antiferromagnetic coupling by PNR and SMR. Growth of the primary domains on passing the bulk-spin-flop transition was established. The domains were found to revert to their native state only in a field considerably higher than the apparent saturation field, a phenomenon referred to as the supersaturation domain memory effect (SDME). We present a comparative PNR study of two antiferromagnetically coupled Fe/Cr MLs with different magnetisation curves. We show that the distribution of the layer-layer coupling rather than the magnetic structure of the Cr spacer layer is responsible for the SDME.
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.
The temperature dependences of the Grueneisen parameter, heat capacity, bulk modulus and linear thermal expansion coefficient of sixteen III-V zincblende compounds are studied by first-principles response-function calculations. The fundamental relationships among these physical parameters are explored. Negative thermal expansions at lower temperature are found in most of these III-V phases except for the nitrides and boron compounds. By analyzing the cell-volume dependences of the phonon spectrum, it is found that the phases with a negative thermal expansion show a significant acoustic phonon weakening at the X-point in their phonon dispersion, while slight weakening is only seen around the L-point for those boron phases. There is no sign of phonon weakening in the nitrides. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Separation of the bulk soluble chemical salts from the insoluble metal hydroxides and radionuclides is central to the strategy of disposing Hanford tank waste. Sludge washing and caustic leaching have been selected as the primary methods for processing the 230 million L (61,000,000 gal) of Hanford tank waste. These processes are very similar to those selected for processing waste at the West Valley Site in New York and the Savannah River Site in South Carolina. The purpose of sludge washing is to dissolve and remove the soluble salts in the waste. Leaching of the insoluble solids with caustic will be used to dissolve aluminum hydroxide and chromium hydroxide, and convert insoluble bismuth phosphate to soluble phosphate. The waste will be separated into a high-level solids fraction and a liquid fraction that can be disposed of as low-level waste after cesium removal. The washing and leaching operations involve batchwise mixing, settling, and decanting within the ...
The excess energy of several III-V and II-VI strained-layer semiconductor superlattices ({ital AC}){sub {ital p}}(BC){sub p} is studied as a function of the repeat period {ital p} and orientation {bold G}=(001), (110), (111), and (201), using first-principles calculations. We discover a number of universal features, including the predicted instability for nearly all {ital p}'s and {bold G}'s with respect to {ital bulk} disproportionation, the identification of chalcopyrite as a metastable ordered structure, and the stability of all thin {ital epitaxial} (110) and (201) and most common-anion (001) superlattices relative to coherent phase separation.
NiMnSb has attracted a great deal of interest as a spin injector/detector in spintronic devices because it has a Curie temperature of 728 K and is predicted to be half-metallic (100% spin polarized). NiMnSb has been reported to have greatly reduced surface polarization, and to lose its half metallicity above 80 K. Here we report the investigation of the surface polarisation and electronic structure of NiMnSb by measurement of the transport spin polarization using point contact Andreev reflection spectroscopy, and anomalous Hall effect in thin films on Si(0 0 1). A comparison to bulk properties is made.
The spin relaxation processes within the pyrochlore Ho{sub 2}Ru{sub 2}O{sub 7} have been investigated by neutron scattering and bulk property techniques. A single-ion process, that is thermally activated, dominates the spin-spin relaxation spectrum above 2 K. Assuming Arrhenius behaviour, we found an activation energy {delta} = (329 {+-} 6) K and characteristic relaxation time {tau}{sub 0} (5.2 {+-} 0.3) x 10{sup -12} s in the paramagnetic state, akin to those found in the spin ice, Ho{sub 2}Ti{sub 2}O{sub 7}. Atlow temperature (T<95 K) the activation energy lowers and below 20 K the entropy and ac susceptibility are similar to that observed in other spin ice compounds within a 10 kOe field.
The spin relaxation processes within the pyrochlore Ho_2Ru_2O_7 have been investigated by neutron scattering and bulk property techniques. A single-ion process, that is thermally activated, dominates the spin-spin relaxation spectrum above 2 K. Assuming Arrhenius behaviour, we found an activation energy #DELTA# = (329 #+-# 6) K and characteristic relaxation time #tau#_0 (5.2 #+-# 0.3) x 10"-"1"2 s in the paramagnetic state, akin to those found in the spin ice, Ho_2Ti_2O_7. Atlow temperature (T<95 K) the activation energy lowers and below 20 K the entropy and ac susceptibility are similar to that observed in other spin ice compounds within a 10 kOe field.
Interactions between cationic dye-cationic surfactant and anionic dye-cationic surfactant systems were investigated in aqueous solutions using spectrophotometric method at 288.15, 298.15, 308.15 and 318.15K. C.I. Basic Red 9 (BR9) and C.I. Acid Blue 25 (AB25) were used as cationic and anionic dyes, respectively, and hexadecyltrimethylammonium bromide (HDTMABr) was selected as cationic surfactant in this study. Although there was an interaction between the AB25 and the HDTMABr molecules, an interaction between the BR9 and HDTMABr did not occur due to the electrostatic repulsion forces. Binding constants and partition coefficients between the micellar and the bulk water phases for the AB25-HDTMABr system were calculated from the changes in absorbance values and the critical micelle concentra...
The growth and properties of Si{sub 1{minus}y}C{sub y} and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y} alloys pseudomorphically strained on Si(001) will be reviewed. Although the bulk solubility of carbon in silicon is small, epitaxial layers with more than 1 at.% C can be fabricated. The relation between substitutional and interstitial carbon incorporation will be presented. Substitutionally incorporated C atoms allow strain manipulation, including the growth of strain-free or inversely strained Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y} layers. The mechanical properties, microscopic structure, thermal stability, as well as the influence of C atoms on band structure will be discussed.
Heavy ion irradiation on tantalum metal target with 57 MeV {sup 11}B{sup 4+} leads to the production of no-carrier-added radioisotopes of platinum, {sup 187,188}Pt and iridium, {sup 187,188}Ir in the matrix, which have been effectively separated from the bulk target and from each other with suitable anion exchangers employing liquid-liquid extraction (LLX). Also {sup 188,189}Pt and {sup 188,189}Ir radionuclides have been produced, from their short-lived precursors {sup 188,189}Au, in {sup 12}C{sup 6+} irradiated tantalum matrix. Gamma-spectroscopy has been utilised to determine the production, extent of separation and purity of the radiotracers at different stages of the experiment. (orig.)
Smooth and notched fatigue behavior is presented for an age-hardenable metastable #beta#-titanium alloy (Ti-3Al-8V-6Cr-4Mo-4Zr). The as-solution heat treated condition exhibits low fatigue limits and high ductility, while the high-strength condition has higher fatigue limits, but poor ductility. A new thermomechanical technique employs shot peening and heat treating to selectively age-harden only the surface. The fatigue limit is improved to levels well above that of the high strength condition, while retaining appreciable ductility, since the bulk material remains in the solution heat treated condition. (orig./MM).
The Los Alamos Nuclear Material Accounting and Safeguards System (MASS) is a near-real-time accountability system for bulk materials, discrete items, and material undergoing dynamic processing. MASS has evolved from an eighty-column card based process control system to a very sophisticated computer system. The security of the MASS computer system is provide through various access controls. There are two kinds of access control to be addressed. They are physical access control to the hardware which make up the system, and access control to the software. There are many features which provide a measure of security to the hardware that will be discussed. Access to the software is controlled by a security password. Access to various transaction activities in the system is controlled through the level of MASS user privilege. Details of MASS user privilege will be discussed.
The properties of individual radioactive particles present in a sample, such as a swipe, are more interesting than bulk properties of the sample. The present work focuses on instrumentation that provides position-sensitive spectral information non-destructively from the sample. The experimental part of the work was realized using a device called PANDA (Particles And Non-Destructive Analysis). The detector setup used in the study contains a broad-energy HPGe gamma-ray detector and a position-sensitive alpha detector. Both detectors are connected to a time-stamping event-mode data acquisition system. The method is shown to locate particles with sub-millimetre accuracy and distinguish the interesting particles from non-interesting ones. (author)
The physical foundations of a variety of emerging technologies --- ranging from the applications of quantum entanglement in quantum information to the applications of nonequilibrium bulk and interface phenomena in microfluidics, biology, materials science, energy engineering, etc. --- require understanding thermodynamic entropy beyond the equilibrium realm of its traditional definition. This paper presents a rigorous logical scheme that provides a generalized definition of entropy free of the usual unnecessary assumptions which constrain the theory to the equilibrium domain. The scheme is based on carefully worded operative definitions for all the fundamental concepts employed, including those of system, property, state, isolated system, environment, process, separable system, system uncorrelated from its environment, and parameters of a system. The treatment considers also systems with movable internal walls and/or semipermeable walls, with chemical reactions ...
Recent progress in yttrium-based oxide high-temperature superconductors has enabled the production of a large diameter bulk with a strong flux-pinning force. A combination of this superconductor and a permanent magnet makes it feasible to fabricate a noncontact, non-controlled superconducting magnetic bearing with a very small rotational loss, applicable to a flywheel energy storage system. A conceptual design of an 8 MWh flywheel energy storage system using the new bearing has been developed, based on measured data on a miniature bearing model, which proved to be potentially capable of achieving a high energy storage efficiency of 84 pc. A 100 W h-class experimental system was then built, which attained a high revolution rate of 17000 rpm, with a rotational loss of about 0.6 W. (authors). 2 refs., 7 figs., 3 tabs.
The thermal transformation of Al-base icosahedral phases was studied in-situ by real time neutron powder diffraction. Different compositions have been selected in order to vary the initial phase morphology and change the neutron scattering contrast between species. Alloys with low silicon and large aluminium contents produce first the orthorhombic O-Al_6Mn modification. In alloys with larger silicon content, the #alpha#-AlMnSi cubic phase appears soon after the beginning of the transformation but is still preceeded by O-Al_6Mn. Depending on compositions, the crystallization of the icosahedral phase is controlled either by the diffusion of Al through its interface with the residual fcc aluminium or that of Si within the bulk. The results are discussed in the light of current structural models. (author) 40 refs., 14 figs., 3 tabs.
We present a novel fabrication route yielding Raney-platinum film electrodes intended as glucose oxidation anodes for potentially implantable fuel cells. Fabrication roots on thermal alloying of an extractable metal with bulk platinum at 200^oC for 48h. In contrast to earlier works using carcinogenic nickel, we employ zinc as potentially biocompatible alloying partner. Microstructure analysis indicates that after removal of extractable zinc the porous Raney-platinum film (roughness factor ~2700) consists predominantly of the Pt3Zn phase. Release of zinc during electrode operation can be expected to have no significant effect on physiological normal levels in blood and serum, which promises good biocompatibility. In contrast to previous anodes based on hydrogel-bound catalyst particles the ...
Presented are nomographs for calculating volume of bulk materials (e.g. coal, ores, sand, limestone) in conical or oblong piles formed by means of throwers and other mechanical transporting devices. The author explains that when a thrower is stationary, the pile formed resembles a cone and its projection on the ground is roughly circular. If thrower is moving, in general along a straight path, the final shape is more oblong, resulting from overlapping of separately formed cones. Slope of piles depends on the angle of repose which material makes with the horizontal when piled. This angle depends on such factors as internal friction of material stored, the throwing impact, fineness of grains, and moisture content. Volume is determined from the angle of repose and geometrical data on the area occupied by the pile.
The pressure dependence of the photoluminescence (PL) transition associated with the fundamental band gap of ZnO nanowires has been studied at pressures up to 15 GPa. ZnO nanowires are found to have a higher structural phase transition pressure around 12 GPa as compared to 9.0 GPa for bulk ZnO. The pressure-induced energy shift of the near band-edge luminescence emission yields a linear pressure coefficient of 29.6 meV/GPa with a small sublinear term of -0.43 meV/GPa{sup 2}. An effective hydrostatic deformation potential -3.97 eV for the direct band gap of the ZnO nanowires is derived from the result.
Wood-polymer composites (WPC) have been prepared of pinewood with different monomers using Gamma radiation: acrylamide, butyl acrylate, butyl methacrylate, styrene, acrylonitrile, and polyester. The polymer loading was determined as a function of monomer concentration and absorbed dose. The data show that polymer loading increases by increasing the monomer concentration. In two cases, BMA and polyester, the polymer loading decreases at high concentrations. This can be explained by the increase of the viscosity. Thus the diffusion of the compound into bulk would be slower. The absorbed dose seems to play a positive role in enhancing the polymer loading by increasing the dose. The mechanical properties, tensile and compression strength, have been improved in the most cases for all monomer concentrations or absorbed doses. Using polyester there was no improvement in the mechanical properties, and using acrylamide the improvement was at high monomer ...
The decommissioning of the Sodium Reactor Experiment is essentially complete. Contaminated materials, equipment, and soil were removed, decreasing the residual radioactivity to levels acceptable for future unrestricted use of the site. The fuel was removed and declad, tooling and techniques to support the decommissioning were developed, bulk sodium and residual sodium films were removed, coolant systems were dismantled, the reactor vessel was dissected, the interior surfaces of the facilities were decontaminated, and waste materials were packaged and shipped to burial sites. Radiation exposure to workers and the public was within the guidelines and as low as reasonably achievable. In performing the project, new decontamination techniques were tested, decontamination equipment was evaluated, and waste disposal methods were developed.
We have performed polarized neutron diffraction measurements on the intermediate valence compound CePd{sub 3} using the D3 spectrometer at the ILL. The results show that at low temperatures, 1.7 K, as well as at 100 K, the field-induced magnetic amplitudes measured in a field of 4.6 T could be interpreted in terms of two contributions: a 4f-type contribution with a Ce{sup 3+} form factor, and an extra delocalized contribution (relatively narrow in q-extent). In particular, we find that the values of the 4f moment deduced from the extrapolation of the neutron data to Q=0 are systematically lower than the values deduced from bulk magnetization measurements performed on the same sample. This difference can be ascribed to a possible positive polarization of the conduction band which is similar at both temperatures.
The relaxations of the Ti(0001) and Zr(0001) surfaces are studied using the plane-wave-basis pseudopotential method within the local-density approximation. We find that the first interlayer spacings of Ti(0001) and Zr(0001) are contracted with respect to the bulk spacings by 6.8% and 6.1%, respectively. Such large relaxations for the close-packed surfaces of Ti and Zr are in good agreement with recent linear-augmented-plane-wave calculations. In addition, we predict a weak vibrational effect on the surface relaxation of Zr(0001) by considering the free energy in the quasiharmonic approximation. This result can be attributed to a very strong bonding between the first- and second-layer Zr atoms as a consequence of the bond-order endash bond-length correlation. copyright 1997 The American Physical Society.
Phytoplankton community composition, density, and succession were studied in tropical commercial ponds with euryhaline tiger shrimp (Penaeus monodon Fabricius) using green-water technology at two different stocking densities [T1 10 post-larvae (PL) m?2 and T2 15 PL m?2] in one grow-out season (May?October 2005) in Leganes, Iloilo, Philippines. Weekly qualitative and quantitative analyses of phytoplankton were done along with physicochemical analyses of the pond waters. A total of 103 taxa belonging to nine different algal classes were observed. Of these classes, the Chlorophyceae, Cyanophyceae and Bacillariophyceae constituted the great bulk of the phytoplankton population. The two treatments did not show any significant differences in the growth pattern of phytoplankton over time and in t...
The structural stability, electronic and elastic properties of ScN under high pressure were investigated by using full-potential linearized augmented plane-wave (FP-LAPW) method. Our calculations indicate that there exists a pressure-induced structural phase transformation from the ambient rock-salt (B1) phase to CsCl-type (B2) phase above 335 GPa. The origin of moderate high bulk modulus, mechanical and high melting point was analyzed by electronic properties. The variations of elastic constants (C_i_j) with volume and pressure have been investigated. Moreover, the volume dependencies of Debye temperature, the longitudinal and transverse elastic wave velocities have been presented.
Abstract Objectives- Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings- Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are mo...
Morphology of castellated Be tiles from the belt limiter exposed to the JET plasma for 56,000 s was examined on both sides of castellated grooves, on plasma-facing and side surfaces of the tiles. The essential results are (i) deuterium retention in the castellated grooves and in other locations is associated with co-deposition of carbon; (ii) the decay length of deposition in the castellation is around 1.5 mm; (iii) no deuterium is detected in bulk Be; (iv) bridging of gaps by molten beryllium occurred but gaps were not filled with Be; (v) on side surfaces of the tiles the formation of BeO layer was detected at a distance of 20 mm and more from the plasma-facing surface. The consequences for a long-term operation of a reactor-class device with several different plasma-facing materials are addressed.
Beta-SiAlON powders have been synthesized using natural clay containing kaolin and quartz by carbothermal reduction and nitridation (CRN), then beta-SiAlON bonded corundum multiphase materials have been sintered using the as prepared powders. The results indicated that both the holding time and sintering temperature are relatively significant in accordance with optimal analysis by orthogonal method. Reaction process can be briefly interpreted by means of X-ray Diffraction and Difference Temperature Analysis as well as phase diagram principle. Bending strength and bulk density were measured in SiAlON in situ bonded corundum materials with doped various sintering agents. Furthermore, the relevant mechanical properties and microstructure were discussed in detail.
We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary values of the bottom Yukawa coupling. We also compute the corrections to the minimization conditions of the effective potential at the same perturbative order. Our results extend the existing O(at^2) calculation, and are relevant in regions of the parameter space corresponding to tan(beta) >> 1. We extend to the Yukawa corrections a convenient renormalization scheme, previously proposed for the O(ab*as) corrections, that avoids unphysically large threshold effects associated with the bottom mass and absorbs the bulk of the corrections into the one-loop expression. For large values of tan(beta), the new contributions can account for a variation of several GeV in the lightest Higgs boson mass.
We discuss an experimental technique aimed at tagging electron neutrinos in multi-GeV artificial sources on an event-by-event basis. It exploits in a novel manner calorimetric and tracking technologies developed in the framework of the LHC experiments and of rare kaon decay searches. The setup is based on an instrumented decay tunnel equipped with tagging units that intercept secondary and tertiary leptons from the bulk of undecayed pi+ and protons. We show that the taggers are able to reduce the nue contamination originating from K_e3 decays by about one order of magnitude. Only a limited suppression (~60%) is achieved for nue produced by the decay-in-flight of muons; for moderate beam powers, similar performance as for K_e3 can be reached supplementing the tagging system with an instrumented beam dump.
We investigate two routes to obtain negative group velocity bands in two-dimensional phononic crystal structures. The negative dispersion originates from the resonances of sub-wavelength building blocks and as such, the system should be regarded as acoustic metamaterials. The first kind of acoustic metamaterial exhibits effectively negative bulk modulus and negative mass density simultaneously. Monopolar and dipolar Mie resonances are combined to achieve an effective medium with negative refractive index. In particular, we present a double negative metamaterial for airborne sonic waves. We then show that we can obtain negative group velocity from quadrupole resonances, and the result is explained using the quasi-static approximation. The negative dispersion in quadrupole bands cannot be de...
In the formation of A-15 superconducting compounds by solid state diffusion, the time exponent in the growth law under different experimental conditions varies widely from about 0.25 to 1.0. Specific models of growth for different operative rate-controlling conditions are proposed. When the diffusion of B atoms in the matrix is rate-controlling, the thickness of the reacted compound layer increases as tsup(1/2) or tsup(2/3). When the diffusion of B atoms through the compound layer is rate controlling, a tsup(1/2) dependence both for bulk diffusion and grain-boundary diffusion is predicted. When substantial grain growth occurs in the reacted layer during the diffusion anneal, the time exponent observed could be as low as 1/4. Experimental data in support of the predictions of the proposed models are presented. (author).
The Sputter coefficient of accelerated CO{sub 2} cluster ions hitting surfaces of various materials is investigated. For copper it varies proportional to the 2nd power of the energy between 155 and 260 keV. The rate of erosion for different target materials varies by two orders of magnitude from tungsten to PMMA. Diamond is eroded fairly quickly, while aluminum is eroded less than corundum (Al{sub 2}O{sub 3}). No simple correlation of the sputter coefficient on the bulk material properties is found. For copper the angular distribution of sputtered material is measured and found to be following roughly a cosine distribution. By using masks different microstructures have been produced in cobalt-samarium magnets, diamond and glass. (orig.)
Radon migration in porous, earthen materials is characterized by diffusion in both the air and water components of the system as well as by the interaction of the radon between the air and water. The size distribution and configuration of the pore spaces and their moisture distributions are key parameters in determining the radon diffusion coefficient for the bulk material. A mathematical model is developed and presented for calculating radon diffusion coefficients solely from the moisture content and pore size distribution of a soil, reducing the need for resorting to radon diffusion measurements. The resulting diffusion coefficients increase with the median pore diameter of the soil and decrease with increasing widths of the pore size distribution. The calculated diffusion coefficients are suitable for use in simple homogeneous-medium diffusion expressions for predicting radon transport and compare well with measured diffusion coefficients and with empirical ...
We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.
This paper provides an overview of a multi-year research project being conducted at the University of St. Gallen, Switzerland. The objective of the research is to evaluate the role of financial structure in promoting the development of innovative and sustainable energy technologies and its current relationship to innovation and entrepreneurial activity in this important economic sector. In this paper, emphasis is placed on the venture capital segment of the capital market and the electricity segment of the energy industry. We first provide a short overview of the electricity sector. We then briefly discuss the concept of innovation and entrepreneurship and its relationship to our research effort. Finally, the bulk of the paper outlines the conceptual framework for the venture capital element of the research project. We conclude the paper with a summary of our preliminary observations. (Author)
In recent years, increased attention has been focused on the use of lasers in different fabrication steps of solar cells, in particular laser doping to form emitter and/or selective emitter. In this method the laser energy is used to melt silicon, allowing the diffusion of dopant atoms to occur in the liquid phase. The main advantage of this method is the localised nature of the laser beam, which melts and diffuses a limited area without heating the bulk, therefore reducing the possible degradation associated with high temperature processes. At the University of New South Wales a novel laser doping method was developed, which combines the formation of the selective emitter with a self-aligned metallisation pattern. Despite achieving high efficiencies, concerns arose regarding the adhesion ...
The microstructure of the interphase in semicrystalline polymer matrix composites has a dramatic influence on their mechanical properties. Studies have been performed to alter this region and to correlate various interphase morphologies with changes in fiber-matrix adhesion. A reinforced nylon 66 composite, when subjected to specific thermal histories, contains an interphase composed of transcrystallinity. This region has been altered by coating fibers with a diluent, poly(vinyl pyrrolidone), and/or adding the diluent to the matrix material in very small quantities. Interphase morphology was investigated with optical microscopy, and adhesion was measured using a modified fiber pull-out test. It was found that transcrystallinity increases the interfacial shear strength. The effect different interphase morphologies have on the durability of bulk composite samples is currently under investigation.
A 1 MWe power plant using waste wood fuel is to be installed at a US Marine Corps base, which will supply all wood from a landfill site. The core energy conversion technology is a down-draft gasifier supplying approximately 150 Btu/scf gas to both spark ignition and diesel dual-fuel engine-generator sets. Features of the plant design include: (1) grinding wood fuel from a wide range of waste resources, (2) specialized screening for fines removal, (3) complete tar and other waste product control without landfill disposal, and (4) use of process heat for bulk fuel drying, gasifier air pre-heating, and wastewater evaporation.
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10{sup 14} cm{sup -2}) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10"1"4 cm"-"2) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
In this paper we develop an analytical framework for the study of electrochemical impedance of mixed ionic and electronic conductors (MIEC). The framework is based on first-principles and it features the coupling of electrochemical reactions, surface transport and bulk transport processes. We utilize this work to analyze two dimensional systems relevant for fuel cell science via finite element method (FEM). Alternate current Impedance Spectroscopy (IS) of a ceria symmetric cell is simulated near equilibrium condition (zero bias) for a wide array of working conditions including variations of temperature and $H_2$ partial pressure on a two dimensional fuel cell sample with patterned metal electrodes. The model shows agreement of IS curves with the experimental literature with the relative error on the impedance being consistently below 2%. Important two-dimensional effects such the effects of thickness decrease and the influence of variable electronic and ionic ...
By using a two-step homogenization approach, we derive analytical formulas of effective mass density {rho}{sub e} and effective bulk modulus B{sub e} for two- and three-dimensional acoustic metamaterials of Helmholtz resonators (HRs) in fluid. A negative B{sub e} is found at certain frequencies due to the monopolar resonance, leading to a low-frequency acoustic band gap. A unified picture is presented for metamaterials of HRs and three-component metamaterials of negative {rho}{sub e}. Our work supports recent observations in a one-dimensional array of HRs [N. Fang et al., Nat. Mater. 5, 452 (2006)] and presents important high-dimensional extensions for exploring more fascinating phenomena.
Midway Labs currently produces a 335x concentrator module that has reached as high as 19{percent} active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency ({gt}30{percent}) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales. {copyright} {ital 1997 American Institute of Physics.}
Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa/sub 2/Cu/sub 3/O/sub 7-chi/) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators.
A novel heteropolyanion-based ionic hybrid was prepared by combining the divalent ionic liquid (IL) cation of 1,1'-(butane-1,4-diyl)-bis(3-methylimidazolium) with the Keggin-structured V-containing heteropolyanion, and characterized by ^1H NMR, FT-IR, ESI-MS, XRD, SEM, TG, BET surface area, melting point, and elemental analysis. Its catalytic activity was evaluated in the hydroxylation of benzene with aqueous H2O2, including the testing of the influence of organic cations, catalytic reusability and optimization of reaction conditions. This hybrid is characterized to be semi-amorphous nanoparticles with a IL-like composition. The hybrid catalyst leads to the liquid-solid biphasic reaction system for hydroxylation of benzene with H2O2, presenting such advantages as high catalytic activity, c...
Classic and recent results for gauge effects on the properties of the normal-to-superconducting phase transition in bulk and thin film superconductors are reviewed. Similar problems in the description of other natural systems (liquid crystals, quantum field theory, early universe) are also discussed. The relatively strong gauge effects on the fluctuations of the ordering field at low spatial dimensionality D and, in particular, in thin (quasi-2D) films are considered in details. A special attention is paid to the fluctuations of the gauge field. It is shown that the mechanism in which these gauge fluctuations affect on the order of the phase transition and other phase transition properties varies with the variation of the spatial dimensionality D. The problem for the experimental confirmation of the theoretical predictions about the order of the phase transitions in gauge systems is discussed.
From the first principles total energy calculations based on full-potential linear augmented plane wave method (FPLAPW), the elastic properties of XPt_3 (X=V, Cr, Mn, Fe, Co, Ni) are reported here. Theoretical values of Young's modulus, shear modulus, Poisson's ratio and Debye temperature are estimated from the computed elastic constants. From the analysis of the ratio of shear to bulk modulus, it is found that these intermetallic compounds are ductile in nature except CrPt_3, which is brittle. The calculated results are compared with other reported values.
Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946?58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10?days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-...
Electronic structure, volume optimization, bulk moduli, elastic constants, and frequencies of the transversal optical vibrations in LiH, NaH, KH, RbH, and CsH are calculated using the full potential augmented plane wave method, extended with local orbitals, and the full potential linearized augmented plane wave method. The obtained results show some common features in the electronic structure of these compounds, but also clear differences, which cannot be explained using simple empirical trends. The differences are particularly prominent in the electronic distributions and interactions in various crystallographic planes. In the light of these findings we have elaborated some selected experimental results and discussed several theoretical approaches frequently used for the description of various alkali hydride properties.
Experiments of highly subcooled nucleate pool boiling of FC-72 with dissolved air were studied both in short-term microgravity condition utilizing the drop tower Beijing and in normal gravity conditions. The bubble behavior and heat transfer of air-dissolved FC-72 on a small scale silicon chip (10 ? 10 ? 0.5?mm3) were obtained at the bulk liquid subcooling of 41?K and nominal pressure of 102?kPa. The boiling heat transfer performance in low heat flux region in microgravity is similar to that in normal gravity condition, while vapor bubbles increase in size but little coalescence occurs among bubbles, and then forms a large bubble remains attached to the heater surface during the whole microgravity period. Thermocapillary convection may be an important mechanism of boiling heat transfer in ...
A first-principles quasiparticle approach to the electronic excitation energies in crystals and at surfaces is described. The quasiparticle energies are calculated within the GW approximation for comparison with photoemission and other spectroscopic experiments. Applications of the method to bulk semiconductors and the Si(111)2[times]l, Ge(111)2[times]l. and H/Si(III) surfaces are presented. In both cases, significant self-energy corrections arising from many-electron effects to the excitation energies are found. Using atomic positions from total energy minimization, the calculated excitation energies explain quantitatively the experimental spectra. This approach thus provides an ab initio means for analyzing and predicting results from spectroscopic probes.
Sintered glass-ceramics have been produced using municipal incinerator solid residues and glass cullet or an inert waste, from feldspars processing, as sintering aids. The capability of three different mixtures, either previously vitrified or not, to be sintered was investigated by means of linear shrinkage, water absorption and bulk density measurements, and by X-ray diffraction analysis and scanning electron microscopy observations. Particular attention has been addressed to the study of particle size effect on the sintering process. The conclusions that can be drawn from the experimental study are that the preliminary vitrification step is essential in order to obtain a dense sintered glass-ceramic product in the 850-1050 C temperature range developing silicate crystalline phases. The optimal powder particle size that confers a good densification degree was found to be < 45 {mu}m. (orig.)
AbstractBackground In recent years nano-metaloxides which easily penetrate into the cells with special interest due to their higher chemical reactivity as compared to that of similar materials in the bulk form. Of particular interest are nano-TiO2 and ZnO, which have been widely used for their bactericidal and anticancerous properties. Purpose The aim of the present study was to examine the bactericidal properties of nano-TiO2 and ZnO combined with visible light on S. aureus and S. epidermitis, known for their high prevalence in infected wounds. Study Using the technique of electron-spin resonance (ESR) coupled with spin trapping, we examined the ability of TiO2 and ZnO nanoparticle suspensions in water to produce reactive oxygen species (ROS) with and without visible light irradiation. Th...
The total hemispherical emittance of an oxide film that formed on 6061-T6 aluminium alloy parts in the Tower Shielding Reactor-II at Oak Ridge National Laboratory was measured from 295 to 773 K using an emissometer and/or a calorimeter. The emittance of this film was critically needed for heat transfer calculations in a simulated loss-of-coolant accident of the reactor. X-ray diffraction analysis identified the film as boehmite (Al_2O_3 x H_2O), which dehydrated to alumina (Al_2O_3) upon heating above 473 K. The measured emittances for the alumina film are in excellent agreement with published values for anodized aluminum films and for bulk alumina. Published values of the emittance of boehmite could not be found for comparison, but evidence is presented that some anodization processes for aluminum yield boehmite and not alumina films.
Porous SnO2 nanotubes were prepared via electrospinning followed by calcination in air. As anode materials for lithium ion batteries, the porous nanotubes delivered a high discharge capacity of 807mAhg^-^1 after 50cycles. Even after cycled at high rates, the electrode still retained a high fraction of its theoretical capacity. Such excellent performances of porous SnO2 nanotubes could be attributed to the porous and hollow structure which facilitated liquid electrolyte diffusion into the bulk materials and buffered large volume changes during lithium ions insertion/extraction. Furthermore, the nanoparticles of nanotubes provided the shorter diffusion length for lithium ions insertion which benefited in retaining the structural stability and good rate performance. Our results demonstrated t...
We have calculated the electronic structure of Eu for the bcc, hcp, and fcc crystal structures for volumes near equilibrium up to a calculated 90 GPa pressure using the augmented-plane-wave method in the local-density approximation. The frozen-core approximation was used with a semi-empirical shift of the f-states energies in the radial Schroedinger equation to move the occupied 4f valence states below the #GAMMA#_1 energy and into the core. This shift of the highly localized f-states yields the correct europium phase ordering with lattice parameters and bulk moduli in good agreement with experimental data. The calculated superconductivity properties under pressure for the bcc and hcp structures are also found to agree with and follow a T_c trend similar to recent measurement by Debessai et al.
Electrostatic fields of the order of 1 V/Angst, as they occur at field emission tips, are comparable to those experienced by valence electrons in atoms and molecules. Such fields are strong enough to induce a significant redistribution of the valence charge in chemical bonds. In this work we investigate the effects on the electronic properties of a single adatom on a metal surface induced by the presence of an electrostatic field. In particular we present the results of a full ab initio DFT calculation, within the embedding method, of the CCV Auger spectra of Si and Mg atoms in and on a jellium-Ag host. Differently from impurities in bulk, Auger spectral profiles of adsorbates on metal surfaces can show notable modifications due to the applied electric field.
In this paper we demonstrate the electrodeposition of nickel, a common ferromagnetic material, in various magnetically desirable shapes including nanowires, nanoparticles and highly faceted shells. In order to obtain three dimensional mesostructures, the electrochemical deposition of nickel was performed on highly oriented pyrolytic graphite (HOPG) under different electrolyte composition and deposition potential conditions. Under potentiostatic deposition at one distinct potential negative with respect to the reversible potential of nickel, three stages of nucleation and growth take place leading to a complex morphology of deposits. However, dual-pulse potential deposition and electrodeposition in low pH solutions causing hydrogen evolution, lead to nickel deposits in the form of nanowires...
Disorder on the string theory landscape may significantly affect dynamics of eternal inflation leading to the possibility for some vacua on the landscape to become dynamically preferable over others. We systematically study effects of a generic disorder on the landscape starting by identifying a sector with built-in disorder -- a set of de Sitter vacua corresponding to compactifications of the Type IIB string theory on Calabi-Yau manifolds with a number of warped Klebanov-Strassler throats attached randomly to the bulk part of the Calabi-Yau. Further, we derive continuum limit of the vacuum dynamics equations on the landscape. Using methods of dynamical renormalization group we determine the late time behavior of the probability distribution for an observer to measure a given value of the cosmological constant. We find the diffusion of the probability distribution to significantly slow down in sectors of the landscape where the number of nearest neighboring vacua ...
X-ray diffraction offers a unique combination of advantages for kinetic study which include the non-destructive nature of the measurement, the use of bulk crystals, and the convenience of the experimental arrangements. These attributes and the availability of position-sensitive detectors and high-flux synchrotron radiation sources make this technique most useful for in situ, dynamical investigations. When using diffraction techniques to determine a diffusion coefficient, the principle of analysis entails a scattering theory and a kinetic model. The former allows the kinetic parameter(s) to be extracted from measured intensity, while the latter relates the kinetic parameter(s) to the diffusion coefficient(s). Three examples are demonstrated: (1) Palladium Silicide (Pd{sub 2}Si) Layer Growth on Silicon, (2) Decomposition of an Ni-12.5at%Si Superalloy, and (3) Short-range Ordering in Cu-Au Solid Solutions.
An all-atom polarizable chloroform (CHCl{sub 3}) potential model has been developed using the classical molecular dynamics techniques. This potential is shown to reproduce reasonably well the structural, dynamical, and thermodynamic properties of bulk liquid CHCl{sub 3} at various temperatures and pressures. With this potential, we carried out computer simulations to investigate the CHCl{sub 3}-H{sub 2}O liquid/liquid interface. Detailed structural and electrical properties at the interface will be analyzed via the density profile, radial distribution functions, molecular orientation, hydrogen bonding, and the z-dependent dipole distributions. Comparison will also be made to the results of the CCl{sub 4}-H{sub 2}O liquid/liquid interface.
We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.
Western Area Power Administration (Western) is a power marketing agency of the US Department of Energy, with jurisdiction in 15 western states. The Salt Lake City Area (SLCA) of Western performs the agency`s mission in parts of Colorado, New Mexico, Texas, Utah, Arizona, Wyoming, and Nevada. As part of its mission, Western owns, operates, and maintains a system of transmission lines for transmitting bulk electrical energy from points of generation to and between delivery points. Part of that system in southwestern Colorado includes the Blue Mesa-Curecanti and Blue Mesa-Salida 115-kV transmission lines. Western proposes to conduct maintenance and improve its access roads for these two transmission lines. This paper discusses the impacts to the existing environment as well as the environmental consequences resulting from the maintenance and construction that is proposed.
A model is developed to represent mechanical strain, stress-enhanced dissolution, and shear dilation as innately hysteretic and interlinked processes in rough contacting fractures. The model is incorporated into a numerical simulator designed to examine permeability change and thermal exchange in chemically active and deformable fractured reservoirs. A candidate engineered geothermal reservoir system (EGS) is targeted. The mechanistic model is able to distinguish differences between the evolution of fluid transmission characteristics of (1) small scale, closely spaced fractures, and (2) large-scale, more widely spaced fractures. Alternate realizations of fracture frequency and scale, exhibiting identical initial bulk permeability, lead to significantly different conclusions regarding perme...
We develop a continuum description for the axial segregation of granular materials in a long rotating drum based on the dynamics of the thin near-surface granular flow coupled to bulk flow. The equations of motion are reduced to the one-dimensional system for two local variables only, the concentration difference and the dynamic angle of repose, or the average slope of the free surface. The parameters of the system are established from comparison with experimental data. The resulting system describes both initial transient traveling wave dynamics and the formation of quasi-stationary bands of segregated materials. A long-term evolution proceeds through slow logarithmic coarsening of the band structure which is analogous to the spinoidal decomposition described by the Cahn-Hilliard equation. {copyright} {ital 1999} {ital The American Physical Society}
We develop a continuum description for the axial segregation of granular materials in a long rotating drum based on the dynamics of the thin near-surface granular flow coupled to bulk flow. The equations of motion are reduced to the one-dimensional system for two local variables only, the concentration difference and the dynamic angle of repose, or the average slope of the free surface. The parameters of the system are established from comparison with experimental data. The resulting system describes both initial transient traveling wave dynamics and the formation of quasi-stationary bands of segregated materials. A long-term evolution proceeds through slow logarithmic coarsening of the band structure which is analogous to the spinoidal decomposition described by the Cahn-Hilliard equation. copyright 1999 The American Physical Society
Anti-reflective coatings made with Teflon AF2400 had the highest damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, maintained the bulk optical properties of a high transmittance from 200 nm to 1600 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.
The determination of residual stress (RS) in case-hardened steel gear truck synchronisers coated with thermal sprayed molybdenum was carried out using neutron and synchrotron X-ray diffraction. Two samples with different coating thicknesses (about 120 ?m and 1.4 mm) and different steel substrates (16MnCr5 and SAE4140, respectively) were investigated. Microanalysis revealed substantial porosity in both samples and some debonding was observed between the thin coating and the substrate. The bulk hardness of the SAE 4140 proved to be much higher than the 16MnCr5 and the surface case-hardening increased it by a further 20%. The full three-dimensional stress depth-profile was determined by neutron diffraction (ND) in both the coatings and the substrates, while synchrotron radiation allowed a dep...
The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10"-"1"6 m"2. Areas free of surface defects had permeability ranging from 10"-"1"4 to 10-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2. This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.).
It is planned to bulk-heat a unit cell of a fusion reactor solid-breeder blanket in a fission reactor to study thermo-mechanical and thermal-hydraulic properties of fusion blankets. This study investigates the neutronic feasibility of using the Power Burst Facility (PBF) for this purpose. Heating rates were calculated for a Li/sub 2/O experiment placed in the PBF test space. The ANISN code and a 56-group coupled neutron-gamma library based on FLUNG and VITAMIN C were used to compute the heating rates. The results show that an average heating rate level of 1-3 W/cc can be produced in PBF with a local power profile that should be typical of a fusion blanket unit cell.
In this context, the bulk ratio of CH4/N2 is examined as a potential alternative geochemical parameter for the assessment of thermal maturity of natural gas and compared to other previously published data. Open-system non-isothermal pyrolysis of low-mature coal from the Manjiaer sag, Tarim basin, yielded generation curves for methane and nitrogen. Analysis of the change of vitrinite reflectance indicates a two-stage process of thermal maturation with increasing temperatures. The relationship between Ro and pyrolysis temperature could be expressed by the following equations: Stage I: Ro = 0.0014T + 0.109, r = 0.9931(Ro Ro = 0.0067T -1.5855, r = 0.9996 (Ro > 0.6%). A kinetic interpretation of the characteristics of nitrogen and methane generation in humic coal during laboratory pyrolysis ind...
The z-phase, existing between 35% and 70% U in Pu, belongs to the high-density phases seen from the point of view of systematics of allotropic modifications of Pu metal. Despite the volume per actinide atom only slightly higher than for a-Pu, it magnetic susceptibility is much higher than for a-Pu and exceeds even the d-Pu value. Similarly, the Sommerfeld coefficient g>40mJ/mol Pu K2 exceeds the experimental d-Pu value. The data confirm that the volume is not the primary control parameter affecting the situation around the Fermi level of common Pu phases and they point against the traditional belief that they are essentially narrow 5f band systems. Electronic structure calculations suggest that the 5f states of Pu have slightly lower occupancy comparing with d-Pu. A tendency to the 5f loca...
Accurate full-potential self-consistent linearized augmented-plane-wave (FLAPW) calculations have been carried out for hexagonal boron nitride. The resulting energy-band structure indicates that this material is an indirect-gap insulator and shows the existence of two unoccupied interlayer bands, similar to those found in graphite and graphite intercalation compounds. Chemical bonding is mainly covalent, with a small charge transfer towards the nitrogen atoms. Moreover, model-potential calculations, based on first-principles FLAPW wave functions and potentials, have been used to study slabs of thickness up to 35 layers. Contrary to the case of graphite, our results do not provide evidence of surface states associated with the interlayer bands.
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...
The colonization of an implant surface by bacteria is an extremely important medical problem, which often leads to the failure of medical devices. Modern surface modification techniques, such as ion implantation, can confer to the surfaces very different properties from those of the bulk underlying material. In this work, austenitic stainless steel 316 LVM has been superficially modified by Si^+ ion implantation. The effect of surface modification on the biocompatibility and bacterial adhesion to 316 LVM stainless steel has been investigated. To this aim, human mesenchymal stem cells (hMSCs), as precursor of osteoblastic cells, and bacterial strains relevant in infections related to orthopedic implants, i.e., Staphylococcus aureus and Staphylococcus epidermidis, have been assayed. For the ...
We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.
Concerns about groundwater contamination as well as pesticide residues in food and soil have fuelled vigorous debates about the sustainability of chemical-intensive agriculture. Search has been prompted for agronomic strategies with lower environmental hazards. In this multidisciplinary study we compared the characteristics of soils from 20 agricultural farms selected in five geographical areas of Southern Italy with different soil types. In each farm, fields with management regime classified as high-input (HIMR, intensive cultivation under plastic tunnels) or low-input (LIMR, tree orchards) were selected. Soil samples were analyzed for 31 parameters including physical and chemical properties (bulk density, water holding capacity, texture, pH, limestone, electrical conductivity, organic C ...
We compare the metallicities of stars with radial velocity planets to the metallicity of a sample of field dwarfs. We confirm recent work indicating that the stars-with-planet sample as a whole is iron rich. However, the lowest mass stars tend to be iron poor, with several having [Fe/H]0.48) that contributes to but does not explain the mass-metallicity trend in the stars-with-planets sample. We use Monte Carlo models to show that adding an average of 6.5 Earth masses of iron to each star can explain both the mass-metallicity and the age-metallicity relations of the stars-with-planets sample. However, for at least one star, HD 38529, there is good evidence that the bulk metallicity is high. We conclude that the observed metallicities and metallicity trends are the result of the interaction of three effects; accretion of about 6 Earth masses of iron rich material, selection effects, and in some cases, high intrinsic metallicity.
The magnetic susceptibility of GaAs samples containing a large concentration of native defects was investigated by dc magnetization measurements. Thin GaAs films grown by molecular-beam epitaxy at very low temperatures and bulk GaAs:S samples irradiated with fast neutrons have been studied. For all samples, the susceptibility follows a Curie-Weiss law, indicating the presence of localized magnetic moments. These moments are attributed to unpaired spins located at the native defects. Negative Curie-Weiss temperatures found for both neutron-irradiated and low-temperature-grown GaAs is a clear manifestation of an antiferromagnetic interaction between the moments. The presence of a highly inhomogeneous distribution of native defects has to be assumed to account for the observed antiferromagnetic ordering.
Our Andreev reflection measurements (Phys. Rev. Lett. 87 (2001) 137005) along with other experiments have led to a general consensus that MgB{sub 2} is a multiband superconductor with two main superconducting gaps closing at the same T{sub c}. Here we show the behavior of the small gap as a function of the temperature and magnetic field. This gap is isotropic with T{sub c} of the bulk material but with a specific small (crossover) critical magnetic field of about 1 T much lower than the real H{sub c2}. The latter field is anisotropic and is rather governed by the large gap and strongly anisotropic Fermi surface of the material.
Single-particle combustion of coal char is analyzed using a generalized shrinking core model. Finite volume method, which was earlier employed by the authors in solving moving boundary problems involving fluid-solid noncatalytic reactions in general, is used to solve fully transient mass and energy equations. The model takes into account convection and diffusion inside the particle as well as in the boundary layer. The computed results are compared with the experimental data of the authors for combustion of coal char in a fluidized bed combustor. The effects of parameters such as bulk temperature and initial particle radius on the combustion dynamics are examined. The phenomena of ignition and extinction are also investigated. Finally, the importance of Stefan flow, originating due to nonequimolar counterdiffusion, on combustion of coal char is analyzed.
Wood plastic composites (WPCs) are comprised of wood flour and thermoplastic polymer. The matrix is typically high-density polyethylene, poly (vinyl chloride), or polypropylene. The effect of morphology and micromechanics of wood flour particles on the mechanical performance of the bulk composite is a relatively unexplored area. The knowledge about the in situ properties of wood particles and the interfacial properties between the wood particles and the polymer matrix in the bio-composites is very limited. The objective of this work is to characterize the full-field deformation and strain distribution in and around wood particles embedded in polymer matrix. The mechanical tests are performed in small-scale tensile loading stage on thin composite samples containing 1-3 wood particles orient...
The ammoxidation of propane over VSb{sub y}O{sub x} catalysts (y=1, 2, 5) was investigated with respect to the role of different oxygen species in the selective and non selective reaction steps using transient experiments in the Temporal Analysis of Products (TAP) reactor. Only lattice oxygen is involved in the oxidation reactions. Using isotopic labelled oxygen it is shown that two different active sites exist on the surface. On site A, which can be reoxidized faster by gas phase oxygen compared to site B, mainly CO is formed. On site B CO{sub 2} and acrolein as well as NO and N{sub 2}O in the presence of ammonia in the feed gas are formed and reoxidation mainly occurs with bulk lattice oxygen. (orig.)
The bulk removal of CO/sub 2/ from industrial gases is a frequently applied process in the field of gas-treating. Usually chemical solvents are used in order to increase both the solvent-loading capacity and the absorption rate. These solvents often are aqueous solutions of alkanolamines. The loaded-liquid is regenerated at high temperatures with the aid steam. In the present study absorption rates are experimentally determined in various mixtures of amines over a wide range of concentrations. Simultaneously, a model was developed for the description of mass transfer accompanied by parallel reversible chemical reactions. The equations of this mass transfer model could not be solved analytically and therefore numerical techniques were used to obtain an exact description of this process. This model also includes the asymptotic situations of homogeneous catalysts and shuttle mechanism for which in the literature several approximate solutions have been presented. The ...
It has been shown by recent experiments that bulk immiscible metals (e.g. Ag/Cu, Ag/Co and Au/Ni) can form binary alloys on certain surfaces where the substrate mediates the elastic misfits between the two components, thus relieving the elastic strain in the overlayer. These novel surface alloys exhibit a rich phase structure. We formulate a two-component Frenkel-Kontorova model in one dimension to study surface alloy formation. This model can naturally incorporate dislocation formation that plays a crucial role in determining the actual structure of the system. Using energy minimization calculations we provide a phase diagram in terms of average alloy composition and the energy of mixing. Monte Carlo simulations were also performed to study the structure and interaction of the emerging dislocations.
Corrosion is said to be the most dominant factor which affects the physical life of ships and offshore structures. In order to secure the structural safety of ships and offshore structures, it is necessary to take measures to corrosion based on the prediction of condition of progressive corrosion. But such prediction is difficult because the behavior of corrosion`s progress is probabilistic. In this paper, probabilistic model, which could evaluate the degradation of coatings and the successive corrosion of steel members, was proposed in order to explain the tendency of the actual corrosion conditions of existing ships. Then, statistical inferences on the proposed model were made by applying the actual data on plate thickness measurements of Bulk Carriers` Cargo Hold. And validity of the proposed model was verified.
The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.
Background: As the global population ages, support for family caregivers who provide the bulk of care to community-dwelling older people is becoming ever more important. However, in many countries, homecare-service practitioners currently do not follow a systematic approach to assessing and responding to caregiver needs. Objectives: The aim of this study was to explore the experiences of caregivers and practitioners who took part in a field test of the Family Caregivers Support Agreement (FCSA) tool, a modified version of the Carers Outcome Agreement Tool (COAT) initially developed as the result of an Anglo-Swedish study. Both the COAT and the FCSA are designed to facilitate partnerships between caregivers and practitioners so that needs assessment and subsequent support services are negot...
In recent years, interest in the development of a polymer electrolyte fuel cell (PEFC) has considerably increased due to its advantages (e.g., high power density) compared with other fuel cell systems, and its potentials to become the power plant for the next generation, nonpolluting automobile engine. For large scale application of fuel cells, low platinum loading electrode structures are necessary. An electrode based on a highly porous carbonized polyacrylonitrile foam material with very low platinum loading ({approximately} 13 {micro}g/cm{sup 2}) was prepared. The performance of this electrode for oxygen reduction was evaluated and compared with bulk platinum and glassy carbon electrodes.
The Early Bronze Age barrows at Irthlingborough and Gayhurst in central England are notable for the large number of cattle (Bos taurus) remains associated with their human Beaker burials. Previous work using strontium isotope analysis has indicated that most of the cattle analysed, and one aurochs (Bos primigenius), were of local origin [Towers, J., Montgomery, J., Evans, J., Jay, M., Parker Pearson, M., 2010. An investigation of the origins of cattle and aurochs deposited in the Early Bronze Age barrows at Gayhurst and Irthlingborough. Journal of Archaeological Science 37, 508-515.]. In this study, stable isotope analysis of enamel and bone was carried out to investigate whether the mature cattle had experienced similar husbandry practices, climate and environment. Bulk carbon, nitrogen a...
Plerocercoids of the tapeworm Spirometra mansonoides produce a substance that stimulates growth of experimental hosts. We report purification of plerocercoid growth factor (PGF) to homogeneity by a process involving isolation and solubilization of plerocercoid membranes, isoelectric point selection by chromatofocusing chromatography or preparative isoelectric focusing, and anion-exchange chromatography. A radioreceptor assay (RRA) for human growth hormone (hGH) was used to detect PGF and purity of the 27.5-kDa protein was judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Proteolytic activity was detected in the 27.5-kDa protein by gelatin substrate PAGE. Characterization of PGF as a neutral cysteine proteinase was based on substrate and inhibitor specificities and dependence on pH and thiol-containing reagents. The association of hGH agonist and proteinase activities was shown by comparing RRA and hydrolytic activities in the presence ...
The most classic information on the syntrophic microorganisms in an anaerobic bacteria symbiotic system may be methanobacillus omelianskii. These bacteria were isolated as ones degrading alcohols such as ethanol into methane and were stably preserved for more than 20 years. But, it was clarified by later researches that this was a kind of symbiotic cocultivation system of the bacteria (S strain) which oxidizes ethanol into acetic acid, hydrogen, and carbon dioxide, and a kind of bacteria of the methanobacterium genus which produces or synthesizes methane from hydrogen and carbon dioxide. Such a symbiotic system of two kinds of anaerobic bacteria is the one of a kind of bacteria which produces hydrogen by oxidizing substances and of another kind of bacteria which consume hydrogen. Various kinds of symbiotic systems including those of animal-and-bacteria, and those of plant-and-bacteria exist in the nature. Symbiotic microorganism systems under very peculiar ...
Concerning the coal liquefaction research under way at the National Institute for Resources and Development, its purpose, contents, achievements, problems, future tasks, etc., are recapitulated. At the meeting, the coal liquefaction research is explained and discussed. Study tours are conducted to a liquefaction plant site, hydrolytic liquefaction facilities, and liquefaction facilities involving ultra-strong acid. Explanations are given on sub-themes of research in and after fiscal 1992 and the future prospects, and discussion is held on general matters. Various views and opinions are expressed by the committee members. Some ask what the chemical structure of coal is and what the model substance that represents coal is. Another insists that basic research on coal structure and reactivity be reconstructed. Those whose goal is to put the technology to practical use express their opinions that a clear position be given the liquefaction technology in the industrial ...
Microbial indicators in the environmental water are categorized as follows. 1. Index for pathogenic microbial contamination, especially enteric canal based ones. 2. Index for the ordinary microbial contamination. 3. Index for nutritive assessment. 4. Index for the treating effect of final effluent discharged into an environmental water. 5. Index for distinction of of the contamination source. Above 1 and 2'' are among the indices which cannot be replaced by other physico-chemical substances or indices. Up to the present time, 1'' is assessed by a coliform group and 2'' by the bacteria. Recently, however, the status on the microbial contamination of the environmental water is changing, thus urging the reexamination of the assessment systems. This report describes the following items. Characteristics and the elements of the indices (enteric canal based pathogenic microbial contamination); indices under examination ...
Quantitative trait loci (QTL) for growth traits, water use efficiency and tolerance/resistance against metals and herbivores have been identified. A hybrid F2 population originating from a cross between a Salix dasyclados-clone (SW901290) and a S. viminalis-clone ('Jorunn') was used for the different studies in this project. The growth response was analyzed in a greenhouse experiment with two water treatments, normal and drought. In addition, three field experiments with contrasting soils and climates were established. QTL specific for each treatment or field environment but also QTL stable over the treatments or field environments were detected. Each QTL explained from 8 to 29 % of the phenotypic variation depending on trait, treatment or field environment. Clusters of QTL for different traits were mapped indicating a common genetic base or tightly-linked QTL. Stable QTL identified for dryweight can be useful tools for early selection in Salix. In a separate ...
Industrial facilities offer a wide variety of design challenges to engineers, including the mechanical engineers who design the HVAC, the process, exhaust, and other required mechanical systems; the mechanical contractors who install and maintain the systems (and who also may do design work); and the owners` engineers who are responsible for the day-to-day operation of their facilities. Along with the responsibility to see that all systems function as intended is the responsibility to ensure that all worker health concerns are addressed. These include heat stress avoidance and the proper control of harmful substances. The services of industrial hygienists may be required to ensure this. These may be independent consultants or the staff members of mechanical design firms. In addition, it is not unusual for major corporations that own manufacturing plants to have staff industrial hygienists. The accompanying sidebar presents a checklist of items to be considered when ...
A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including icosapentanoic acid. Culture under high temperatures or normal pressure increases content of such unsaturated ...
A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using europium (Eu{sup 3+})-tetracycline (TC) complex as a fluorescent probe, in the buffer solution of pH 7.60. NADP can remarkably enhance the fluorescence intensity of the Eu{sup 3+}-TC complex at {lambda} = 612 nm and the enhanced fluorescence intensity of Eu{sup 3+} ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.4 x 10{sup -7} to 2.2 x 10{sup -6} mol l{sup -1} with detection limit of 6.9 x 10{sup -8} mol l{sup -1}. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu{sup ...
College students are more at-risk for developing a gambling problem than the general adult U.S. population. Information behavior and information seeking theories, as well as empirical evidence, indicate that one resource that may provide guidance for students dealing with this issue is the college counseling center website (CCW). This study addressed the presence and nature of problem gambling messages on CCWs. As a random sample, 203 CCWs were selected to assess how frequently they provided any information about problem gambling, as well as the specific types of communications CCWs offered on this topic. Results showed that CCWs rarely included any messages about problem gambling. Specifically, only 15% of all CCWs contained information about problem gambling. Furthermore, messages about problem gambling were presented significantly less frequently than messages involving alcohol abuse, substance abuse, depression, anxiety/stress, and psychological struggles with ...
The criterion the study is based on in evaluating environmental risks is the possibility of harmful changes in air, water and soils rather than the harmful environmental impacts these changes are caused by. The two significant criteria, i.e. the evaluated environmental hazards potentials or 'value parameters', and the evaluated damage-to-the-environment probabilities or 'safety parameters', reveal the respective environmental risks or 'risk factors'. These risk factors are classified by 23 environmental risk parameters for differentiation between low-risk and high-aid for pollution abatement measures provided that one fixes acceptance limits for the environmental parameters. As a rule the environmental risks of technical facilities which handle hazardous materials can be evaluated appropriately and the results can be compared. (orig./HSCH).
The genetically significant dose (GSD) is an index variable which exclusively allows to describe the genetic risk in the progeny of a population due to the application of ionizing radiation and radioactive substances in one part of this population. It may result in wrong interpretation of population exposure at increasing incidence of examinations in a population involving ionizing radiation and radioactive drugs at simultaneously increasing application of alternative methods in children and adolescents owing to the fact that it indicates a downward trend although somatic exposure of this population has increased. Therefore, it is recommended to state both the GSD and the level of somatic radiation exposure of the population taken from the individual sources for the comparison and assessment of radiation exposure from various sources in future. Although the somatically significant dose constitutes the suitable variable complementary to GSD in thus context, it is ...
Planktivores, zooplankton grazers, and macrobenthos were studied to determine how changes in animal community structure may alter the flow of material in Dunham Pond, CT. Chaoborus and chironomid larvae were studied to determine how they affect the flux of matter across the sediment/water interface. This was done by incubating undisturbed cores in situ and relating changes in water chemistry to larval density. The log-transformed flux rates of iron, manganese, and phosphorus were linearly related to larval biomass. Functional groups may be successfully used to predict rates of material flow. Changes in the mass of macroinvertebrates affect the flux rates of redox-active substances across the sediment/water interface. The use of population densities and feeding characteristics to estimate trophic transfer in Dunham Pond indicate that (1) visual planktivory by larval perch may result in overutilization of prey, (2) ambush planktivory by univoltine Chaoborus appears ...
Determination of principal and impurity components in monocrystals of erbium and yttrium formates grown on the basis of high-pure formates from oriental primers, using the method of isothermal evaporation of the salt aqueous solutions with pH 4.4 - 4.5, is described. Er and Y were determined complexonometrically by the titration of the complex with arsenazo 1 by EDTA solution, and formate-ion was determined iodometrically. Impurities were analyzed by atomic-absorption and titrimetric methods. The atomic-absorption method permits to determine in the monocrystal from 1 x 10"-"4 to 5 x 10"-"3 % Mg at relative standard deviation S_r = 0.05; from 1 x 10"-"3 to 2.5 x 10"-"2 % Ca at S_r = 0.07 and from 2 x 0"-"4 to 5 x 10"-"3 % Pb ar S_r = 0.08.
The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding {alpha}- and {beta}-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CC{alpha} and CC{beta} values of 0.02-0.30 and <1.0 ng ml{sup -1}, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high ...
This report identifies individual contaminants and contaminant mixtures that have been measured in the ground at 91 waste sites at 18 US Department of Energy (DOE) facilities within the weapons complex. The inventory of chemicals and mixtures was used to identify generic chemical mixtures to be used by DOE's Subsurface Science Program in basic research on the subsurface geochemical and microbiological behavior of mixed contaminants (DOE 1990a and b). The generic mixtures contain specific radionuclides, metals, organic ligands, organic solvents, fuel hydrocarbons, and polychlorinated biphenyls (PCBs) in various binary and ternary combinations. The mixtures are representative of in-ground contaminant associations at DOE facilities that are likely to exhibit complex geochemical behavior as a result of intercontaminant reactions and/or microbiologic activity stimulated by organic substances. Use of the generic mixtures will focus research on important mixed ...
The population masses in many coastal zones in Japan, and human activities are greatly effected. The representative water area is the Tokyo Bay. The population of the Tokyo Bay reaches 26 million at present, and a mass of organic substance and nutrient salt flow into it through rivers and sewage-treatment plants, etc. With the improvement of pollution source countermeasure and sewerage in the area, the inflow load to the Bay gradually decreases, but in the inner bay, red tide is generating in the summertime mainly. And, the anoxic water areas observed in bottom layer in summertime make large effects on the seafood. It is a large theme to clarify formation process of the anoxic water area and to solve this problem for the Tokyo Bay in the twenty-first century. In this paper, changes in water qualities and human activities and fundamental approach of water quality conservation of the Tokyo Bay are described. As maintenance and regeneration countermeasures of the ...
Postresection villus hyperplasia is a major compensatory mechanism in the short-bowel patient. Substances capable of augmenting postresection mucosal hyperplasia could have therapeutic implications. Human growth hormone (hGH) and human growth hormone releasing factor (hGHRF) stimulate growth of the gastrointestinal tract; however, the diabetogenic actions of growth hormone limit its usefulness in clinical practice. Plerocercoid larvae of the tapeworm Spirometra mansonoides produce an analog of hGH void of diabetogenic side effects. We assessed effects of plerocercoid growth factor (PGF) on mucosal adaptation following 70% proximal jejunoileal resection in young rats. Mucosal weight, DNA, protein, and total sucrase activity per centimeter of bowel were increased in resected PGF-treated animals compared to resected controls. We conclude PGF augments intrinsic postresection mucosal hyperplasia following extensive intestinal resection. PMID:3665682
This study was undertaken to determine if a combined treatment (marinating in natural plant extracts or vacuum) with irradiation could have a synergistic effect, in order to prevent the lipid oxidation resulting in the development of undesirable flavours. The fresh chicken legs were irradiated at 0,3 and 5 kGy. The fatty acids composition of lipids was identified using gas liquid chromatography. The effect of irradiation treatment combined with a pre-treatment on the fatty acids composition was followed. The day after irradiation, ten panallists were asked to evaluate, using the instruction scaling, the overall appearance, the odor, the flavor and the overall acceptability of the samples. The major fatty acids identified in lipids were oleic acid, palmitic acid, palmitoleic acid and stearic acid. Pre-treatments have a significant effect on linoleic acid (C18:2) and higher fatty acids. The unsaturated fatty acids derived from phospholipids appeared to be more affected by the irradiation ...
Visible smoke of exhaust gas from iron ore sintering plants spoil the scenery around the works. In this paper, the mechanism of formation of visible smoke is discussed by detailed analysis of the exhaust gas components and dust in the Oita No. 1 sintering plant. The main substance of visible smoke was mist condensing in the air during the cooling of exhaust gas that contained 0.1 ppm of sulfuric acid. Sulfuric acid is considered to raise the dew point and so facilitate mist condensation, and to lower the vaporization of visible mist containing sulfuric acid solution. Dust in the exhaust gas is also considered to act as nucleation sites for mist condensation. This proposed mechanism was confirmed by the test remixing SOx-rich gas with desulfurization gas in the Nagoya No. 3 sintering plant. Long trails of visible smoke were observed by remixing SOx-rich gas with exhaust gas. In conclusion, in order to make exhaust gas invisible, it is not sufficient to enhance the ...
'The primary objective of this research project is to acquire a deeper fundamental knowledge of acoustic cavitation and cavitation chemistry, and in doing so, to ascertain how ultrasonic irradiation can be more effectively applied to environmental problems. Four on-going projects will be described in this progress report, The first project is the destruction of carbofuran in a Near-Field Acoustical Processor (NAP), and the hydrodynamic characterization of the reactor. The second project is a comprehensive study of how ultrasonic frequency influences sonochemical reaction rates; the substrate it, the preliminary portion of this study has been hydrogen peroxide formation. The third project in progress is destruction of four polychlorinated biphenyls at 20 kHz. Work so far has been at 20 kHz, but the most significant portion of this project will involve a multi-frequency (ultrasonic frequency) study. Finally, the destruction of a pesticide, dichlorvos, during sonication at 500 ...