Argentina has two operating PHWR nuclear power plants. Atucha I NPP is a pressure vessel type heavy water reactor of 360 MW e with 25 years of operation and Embalse NPP is a pressure tube type CANDU-600 reactor of 640 MW e. Atucha II, a third plant of 600 MW e of the pressure vessel type similar to Atucha I, is being constructed. NASA (Nucleoelectrica Argentina S.A.) currently operates both nuclear power plants. The National Atomic Energy Commission (Comision Nacional de Energia Atomica - CNEA) provides operational support to the plants, including research and development assistance, and actual technical services and maintenance work in different areas. The Chemistry Department, formerly the Reactor Chemistry Department has carried out project and support activities to the plants during the past 20 years. The aim of this work is to describe the present organization and the activities in reactor ...
The objective of this project was to develop new photocatalytic or other innovative process chemistry for the treatment of pink water and related contaminated water.
US Department of Energy (DOE) Order 5400.1 requires the preparation of environmental monitoring plans and implementation of environmental monitoring programs for all DOE facilities. The order identifies two distinct components of environmental monitoring, namely effluent monitoring and environmental surveillance. In general, effluent monitoring has the objectives of characterizing contaminants and demonstrating compliance with applicable standards and permit requirements, whereas environmental surveillance has the broader objective of monitoring the effects of DOE activities on on- and off-site environmental and natural resources. The purpose of this document is to support the Environmental Monitoring Plan for the Oak Ridge Reservation (ORR) by describing the groundwater component of the environmental surveillance program for the DOE facilities on the ORR. The distinctions between groundwater effluent monitoring and ...
The research committee of the Atomic Energy Society of Japan on waterchemistry standard aims at establishing the private standard of waterchemistry of nuclear power plants. The committee gathers up 'BWR waterchemistry management manual', 'PWR primary system waterchemistry management manual' and 'PWR water chemical analysis standard method', and furthermore aims at the standardization of those in future. Looking back on the committee's activities for the past four years, latest results of research of waterchemistry mainly contributing to safe and reliable nuclear power plants were described with the future perspective of waterchemistry and a demanded break-through. (T.T.)
This report discusses environmental surveillance activities conducted on the Nevada Test Site during the first calendar quarter of 1996. Surveillance activities included collection and analysis of air, noble gas, tritiated water vapor, and other water samples. Samples were analyzed for both radiological and non-radiological effluents.
We find dosage of gamma emitters radionuclides of samples collected in the environment of the Chinon nuclear power plant for 2002 and 2003, these results are presented in two tables: concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils) and aquatic environment (sediments) of the site of Chinon in june 2002 in the frame of the annual surveillance, the second table concerns the concentrations in gamma emitter radionuclides of samples collected in the terrestrial environment (soils and lichens) of the site of Chinon in may 2003 in the frame of the annual surveillance. We find also the dosage of free tritium in the water of the Loire river for 2002 and 2003, upstream and downstream to the power plant of Chinon. (N.C.)
A model is described for simulating thermal hydraulic and chemical conditions within fuel crud deposits. Heat transfer takes place by wick boiling in which water flows through the porous deposit and evaporates into steam at the surface of chimneys. The transport and chemistry of dissolved species within the deposit is also modelled. This chemistry includes the equilibrium chemistry of Li/boric acid species, the equilibrium chemistry of Fe/Ni species and the radiolysis chemistry of water. The unique feature of this model is that the chemistry is coupled to the thermal hydraulics via the increase in the saturation temperature with the concentration of dissolved species. This has a profound effect on evaporative heat transfer within thick deposits, leading to conditions that explain the precipitation of LiBO{sub 2} and the ...
Ways of improving the waterchemistry used in the turbine generator stator?s cooling systems at Russian nuclear power plants are considered. Data obtained from operational chemical monitoring of indicators characterizing the quality of cooling water in the turbine generator stator cooling systems of operating power units at nuclear power plants are presented.
In a supercritical water-cooled reactor, property of water changes significantly around the critical point. It is expected that irradiation and change of water property will affect the chemistry and material corrosion. Deep understanding of interactions between supercritical water and materials under irradiation is important. However, comprehensive data on radiolysis, kinetics, corrosion and thermodynamics have not been obtained due to the severe experimental condition. To get such data by experiments and computer simulations, a national program funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT) has been started since December 2002. (author)
Waterchemistry of nuclear power plants has played an important role in reduction of personnel doses, structural materials and fuel integrity assurance, and reduction of radioactive wastes production. Further contributions are requested for advanced utilization of the LWR, advanced fuels and aging management of plants. Since waterchemistry has an effect on all structure and materials immersed and at the same time affected by them, the optimum control not sticking to specific issues and covering the whole plant is required for these requests. Taking account of roles and activities of the industry, governmental institutes and academia, road maps on research and development plans for waterchemistry were compiled into identified eleven items with targets and counter measures taken, such as common basic technologies, dose reduction, SCC mitigation, fuel cans ...
This paper describes the construction of PWR horizontal steam generator in Soviet Union, the waterchemistry treatment for secondary side, the design of steam separator, the test of heat transfer characteristics and operation. (author).
Analytical procedures are described for the determination of organic compounds, metals and radioisotopes in environmental materials, human tissues, urine, feces, and waste water.
Following a brief overview of the terrestrial distribution of boron in rocks, soil, and water, the history of the discovery, early utilization, and geologic origin of borate minerals is summarized....Full Text Available
The symposium covers papers under different sections namely, (i) Core physics and Fuel management, (ii) Commissioning of facilities and systems, (iii) Operational experience and Human resource development, (iv) Fuel handling, Maintenance management and Surveillance, (v) Instrumentation and Control and Power supply systems, (vi) Analysis, modifications and developments for enhancing operational safety, (vii) Chemistry control and Effluent management, (viii) Radiation and industrial safety and (ix) Steam generators, Turbo-generators and other auxiliaries. Papers relevant to INIS are indexed separately. (author)
The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.
The water and steam circuits of steam generators in pressurized-water nuclear power plants are described together with the mechanism of denting, and the corrosion of spacer plates that leads to cracks in tubes by constriction. The different chemical specifications applicable to the water of the secondary circuit of the generators in normal operation and on first commissioning are listed. The results obtained and the measurements of chemical values taken in operation on the water in the secondary circuits of steam generators at Fessenheim and Bugey are presented.
PWR plants have made efforts to maintain the long-term integrity of the steam generators (SG) by reducing the amount of corrosion products entering the secondary side of the SG. Iron entered the SG can cause several problems: degraded heat conductivity of the SG tubes in locations where iron is deposited, water level oscillations in the SG due to tube support plate hole blockage, and initiation and propagation of inter-granular attacks (IGA) and stress corrosion cracking (SCC). One of the most effective measures, high all-volatile treatment (AVT) chemistry has been applied to actual plants to reduce the flow-accelerated corrosion (FAC) coming from the carbon steel piping. The secondary waterchemistry at Genkai NPS 1 and 2 changed, from the Low AVT chemistry to the High AVT chemistry, in November 2006. In this paper, we will describe the results of experiments ...
Elevated pH operation to the pH value of 7.3 at 285degC is known to be effective for the reduction of radiation source in the primary water system of PWRs. A research project was started in 1989 and concluded in 1996 to study and verify the optimum pH and/or Li concentration from the viewpoint of radiation source reduction and materials integrity under improved waterchemistry. This research project is sponsored by the Ministry of International Trade and Industries (MITI) in Japan and has two programs; high pH and high Li. The high Li program was conducted to establish the optimum Li concentration for the high boron concentration region (1100 - 1800 ppm) of the high burn up operation. In this paper, we shall discuss radiation source behavior under high pH conditions and PWSCC (Primary Water Stress Corrosion Cracking) susceptibility of materials with change of primary water ...
Absorption with aqueous amine solvents is at present the most viable technology for CO{sub 2} capture. While this is a proven technology, efforts are ongoing to improve it in order to make it a more attractive technology for large scale use to reduce CO{sub 2} emissions. Finding solvents with better properties is one approach to improving the technology. In this thesis methods in computational chemistry are used to improve the understanding of the chemistry of CO{sub 2} absorption in amine-water systems. The work is also intended to provide models that can be used to predict the performance of new solvents. Such predictive models are intended to facilitate the screening for new solvents
The chemistries of reactants, plasticizers, solvents and additives in an epoxy paint are discussed. Polyamide additives may play an important role in the absorption of molecular iodine by epoxy paints. It is recommended that the unsaturation of the polyamide additive in the epoxy cure be determined. Experimental studies of water absorption by epoxy resins are discussed. These studies show that absorption can disrupt hydrogen bonds among segments of the polymers and cause swelling of the polymer. The water absorption increases the diffusion coefficient of water within the polymer. Permanent damage to the polymer can result if water causes hydrolysis of ether linkages. Water desorption studies are recommended to ascertain how water absorption affects epoxy paint.
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 ...
Advances made in understanding the chemistry and dynamics of the atmosphere in the approximate altitude range of 50 to 90 km are addressed. Attention is given to mesospheric structure and seasonal variations, gravity waves and gravity wave saturation, the effects of gravity waves on thermal, momentum and constituent fluxes, and the effect of gravity waves on airglow emissions. A review of research on tides and planetary waves and their effects on the mesosphere are presented as well as discussions on ozone hydroxyl, water vapor, and noctilucent cloud research. 217 refs.
In designing automatic water quality monitoring networks for a river basin, determination of measurement locations and items is critical to the effectiveness of the total system. In this paper we studied how to decide these two design factors when a monitoring network is designed for the purpose of water quality surveillance and emergency alarm. For measurement locations, candidate sites are chosen based on the intake amount for water supply and the point sources of contamination. Then, detailed locations are decided according to the contaminant flow distance. As for measurement items, characteristics and the accident history of water pollution in the basin must be taken into account. Considering economic aspects, we proposed a two-stage measurement plan: basic components for all locations and selective ones variable for different locations. Proposed methodology is demonstrated ...
The notes describe in detail primary and secondary galvanic cells, fuel cells, electrochemical synthesis and electroplating processes, corrosion: measurments, inhibitors, cathodic and anodic protection, details of metal dissolution reactions, Pourbaix diagrams and purification of waste water from galvanic industries.
Axial offset anomaly (AOA) is caused by the deposition of crud on the fuel cladding of a PWR. When significant levels of crud build up on the cladding, boron can accumulate in the pores of the crud as a concentrated solution or solid phase, and cause the flux depression. Numerous studies have been conducted on the primary waterchemistry to reduce the amount of crud in the primary circuit to avoid radioactivity buildup and unexpected power transition in the plant. However, experiments on the crud are restricted in the laboratory because the crud is a highly radioactive material. The objective of this study is to develop a test method for simulating the deposition of crud in a nuclear power plant
Problem areas in BWRs, PWRs and PHWRs, from the viewpoint of chemistry, and the problem of fission product release in nuclear reactors are discussed. These problem areas are : fuel performance, off-normal waterchemistry due to condenser leaks, the transport and deposition of the activated corrosion and fission products, denting in steam generators (in the case of PWRs), ingress of air in the cover gas helium and consequent radiolysis of D_2O in the moderator circuit (in the case of PHWRs). (M.G.B.).
Steam generators in PWR plants have been subject to denting corrosion as a result of nonprotective magnetite forming on the carbon steel support plate causing the voluminous corrosion product that eventually crimps (dents) the heat transfer tube at the support plate interface. This project was designed to determine the causes of denting and the usefulness of waterchemistry changes meant to arrest denting. This volume of the final report describes laboratory research on the correlation of waterchemistry, superheat, and oxygen ingress with denting in steam generators.
A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary waterchemistry control. (author).
Census and environmental surveillance information on waterfowl that use the Hanford Site 200 Area waste water ponds are described and evaluated. Physical features of the ponds are discussed in relation to their use and suitability for waterfowl. Seasonal distributions observed for the years 1971 through 1974 indicate that the highest use by waterfowl occurs during the spring and fall migratory periods. Base population estimates are 300 to 400 resident waterfowl with a few tens of pairs nesting during the summer. Environmental surveillance data on "1"3"7Cs in muscle tissue are presented for the years 1971 through 1977. Comparisons are made between Columbia River and waste water pond waterfowl, between waterfowl groups, and among ponds. Waterfowl collected from ponds frequently have easily detected levels of "1"3"7Cs in muscle tissue. However, those waterfowl collected from the Columbia River seldom show ...
Most plans for the disposition of surplus nuclear materials involve storage in sealed containers where the evolution of gases from reactions of adsorbed water could present both pressure and flammability hazards[l] . Despite efforts such as calcining the material to minimize the water content prior to packaging, both residual moisture and readsorbed water may be present in the final containers . Given the anticipated temperature excursions during transportation and storage, this water may thermally desorb, increasing the pressure, and/or thermally dissociate to produce H2 gas, increasing flammability hazards . In addition, the radiation from the nuclear material may induce radiolysis of the water with the likely products being water vapor, H2, 02 and H2O2. In order to better understand the relative importance of the thermal- and radiationinduced ...
The present Annual Report of Activities of the Nuclear Regulatory Authority (ARN), prepared regularly from the creation as independent institution, describes across tree parts and seven annexes the activities developed by the organism during 2007. The main topic are: the organization and the activity of the ARN; the regulatory standards; the licensing and inspection of nuclear power plants and critical facilities; the emergency systems; the occupational surveillance; the environmental monitoring; improved organizational. Also, this publication have annexes with the following content: regulatory documents; inspections to medical, industrial and training installations; regulatory guides; measurement and evaluation of the drinking water of Ezeiza.
Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for waterchemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.
Eight years ago, corrosion and tube denting seriously threatened the reliability and design life of steam generators, especially for closed loop arrangements in pressurized water reactors (PWRs). Concentrated research by the Steam Generator Owners Group (SGOG) diagnosed the causes and produced effective solutions, notably guidelines for waterchemistry control in the secondary loop. The guidelines recommend specific levels of water impurities and remedial actions to prevent cooling-water leaks in the condenser, prevent air leaks, limit corrosion product buildup, and remove some impurities while neutralizing others. Continued research in SGOB-II is investigating intergranular corrosion and stress corrosion cracking. 3 figures.
The use of microwave in chemistry has known benefits over conventional heating methods, e.g. reduced reaction times, chemical yield improvement and the possibility if reducing or eliminating the use of organic solvents. We describe herein a procedure for the nitration of salicylaldehyde in water using a domestic microwave oven, which can be used as an experiment in the undergraduate chemistry laboratory. The experiment involves safe and rapid preparation and identification of the position isomers by thin layer chromatography and {sup 1}H NMR, or by their melting points. (author)
A conceptual hydrodynamic model in the Holocene and upper Pleistocene beneath the Louisiana wetlands is described in terms of safety distributions. Porewater safety is calculated from electrical measurements, including resistivity soundings, electric logs, and electromagnetic profiling. Electrical measurements support the primary, basin-wide groundwater flow model; however, the data also indicate secondary contributions from expulsion of fluids under geopressure along active growth faults and from original waters of deposition. Expulsion of water from growth faults has been described previously for deeper sections of the Pleistocene, but has not been reported for the Holocene or upper Pleistocene beneath the Louisiana wetlands. Porewater chemistry variations beneath the coastal wetlands are a consequence of the following (in order of importance): (1) environment of deposition; (2) a basin-wide, regional flow system; (3) ...
Imatran Voima Oy , (IVO) operates two Russian designed nuclear power plants of type VVER440/213. Unit 1 has been operating since 1977 and unit 2 since 1981. First damage of feed water distribution (FWD) pipes was observed in 1989. In closer examinations FWD-pipe T-connection and distribution nozzles suffered from severe erosion corrosion damage. Similar damages have been found also in other VVER-440 type NPPs. In 1994 the first FWD-pipe was replaced by a new design mounted over the tube bundle instead of the old FWD-pipe, which was located inside the tube bundle. The purpose of this paper is to describe the new FWD-pipe and discuss its effects on the steam generator chemistry. (author)
This was a project to investigate the crystal chemistry of OH and H{sub 2}O substitution in silicate minerals by use of X-ray and neutron diffraction methods combined with IR spectroscopy and to interpret and generalize the results using an electrostatic model for these mineral structures. Using these data together with published H position data electrostatic parameters for H sites were calculated from a simple electrostatic model. The data were then used to refine the model for incorporation of H into the wadsleyite structure. This has led to recent work on the synthesis and characterization of hydrous wadsleyites.
Lists of reportable conditions and case definitions are important tools for epidemiologic surveillance. As part of an initiative to encourage occupational disease surveillance systems linked to intervention...Full Text Available
BackgroundThis is a preliminary report of an ongoing prospective bimodality lung cancer surveillance trial for high‐risk patients. Bimodality surveillance incorporates autofluorescence...Full Text Available
12 kind of environmental samples such as soil, underground water, seawater, etc. around the Nuclear Power Plants(NPP) and surface seawater around the Korea peninsula were sampled, For the samples of rain, pine-needle, air, seawater, underground water, chinese cabbage, grain of rice and milk sampled around NPP, and surface seawater and rain sampled all around country, tritium concentration was measured, The tritium concentration in the tap water and the gamma activity in the domestic and imported beef that were sampled at ward in the large city in Korea(Seoul, Pusan, Taegu, Taejun, Inchun, Kwangju) were analyzed for the meat and drinking waters. As the results of analyzing, tritium concentration in rain and tap water were very low all around country, but a little higher around the NPP than general surrounding. At the Wolsung NPP, tritium concentration was descend according to ...
The work of this association is cut according to 6 axes. Three publications: radiological quality of marine and continental waters of the Normandy coast (synthesis 1997 and 1998); preliminary study of the iodine 129 distribution in the environment of the reprocessing plant of La Hague with terrestrial moss (Homalotecium sericeum); radiological surveillance of the aquatic environment of the nuclear facilities on the area of La Hague (1997 and 1998). The second axis concerns the radiation protection with a campaign of radon measures in a school of the Vire rural district (june 1999). The third part is devoted to the radioecology with the surveillance of radioactivity in the aquatic continental environment of nuclear facilities and the radioecological surveillance (1999) of the building site of Cogema la Hague in the area of tidal range of the Moulinets cove. The fourth part concerns the radioactive waste ...
A guidance document on the instrumentation for monitoring and control of cycle chemistry for the steam-water circuits of fossil-fired and combined-cycle power plants was developed within the IAPWS Power Cycle Chemistry Working Group. This technical guidance document has been authorized by the International Association for the Properties of Water and Steam (IAPWS) at its meeting in Doorwerth, The Netherlands, 6-11 September, 2009, for issue by its Secretariat. The members of the IAPWS are: Britain and Ireland, Canada, the Czech Republic, Denmark, France, Germany, Greece, Japan, Russia, and the United States of America, and the associate members Argentina and Brazil, Italy, and Switzerland. In order to achieve suitable chemical conditions in steam-water circuits it is essential to establish reliable monitoring of key parameters on every plant. This enables the demonstration of ...
Several types of corrosion have damaged alloy 600 tubing in the secondary side of steam generators. The types of corrosion include wastage, denting, intergranular attack, stress corrosion, erosion-corrosion, etc. The environments which cause attack may originate from leaks of cooling water into the condensate, etc. When the contaminated feedwater is pumped into the generator, the impurities may concentrate first 200 to 400 fold in the bulk water, depending on the blowdown, and then further to saturation and dryness in heated tube support plate crevices. Characterization of local solution chemistries is the first step to predict and correct the type of corrosion that can occur. The pH is of particular importance because it is a major factor governing the rate of corrosion reactions. The pH of a solution at high temperature is not the same as the ambient temperature, since ionic dissociation constants, solubility and ...
Any student that has spent time in the kitchen knows that hot vegetable oil will pop and spatter violently after coming into contact with water such as that on the surface of foods (meat, fish, potatoes, etc.). This well-known effect can be used as an instructional resource to promote cooperative, active, and inquiry-based learning about central concepts of chemistry including boiling point, miscibility, and density of liquids. The starting point of the learning activity is a demonstration of (i) the effect of adding a drop of water to hot (as for cooking) vegetable oil and (ii) the effect of adding a drop of vegetable oil to hot water (near its boiling point). Intermolecular interactions, properties of vegetable oils, and a variety of other topics, such as the importance of other heat points (smoke, flash, and fire) for oils, the fundamental of the crackle test for checking the presence of ...
Environmental data were collected for most environmental media including air, Columbia River water, external radiation, foodstuffs (milk, beef, eggs, poultry, and produce) and wildlife (deer, fish, and game birds), as well as soil and vegetation samples. In general, offsite levels of radionuclides attributable to Hanford operations during 1979 were indistinguishable from background levels. The data are summarized in the following highlights. Air quality measurements of NO/sub 2/ in the vicinity of the Hanford Site and releases of SO/sub 2/ onsite were well within the applicable federal and state standards. Particulate air concentrations exceed the standards primarily because of agricultural activities in the area. Discharges of waste water from Hanford facilities in the Columbia River under the National Pollution Discharge Elimination System (NPDES) permit were all within the parameter limits on the permit.
The chemical operational concept originally established for the water-steam circuit of Angra II nuclear power plant has undergone several modifications throughout the development of the project. This work discusses the two main modifications giving special attention to the costs involved and analyses the main points and the consequences of such modifications 1 ref., 4 figs., 2 tabs.
The terrestrial biosphere can significantly affect the exchange of water and energy at the biosphere-atmosphere interface. Additionally, the land cover type can affect regional atmospheric chemistry and climate via biogenic volatile organic carbon (VOC) emissions and their formation of secondary organic aerosols. The broad goal of this study is to investigate the impact of land cover and vegetation changes on these specific chemistry and climate effects. The Common Land Model (CLM) is used to parameterize the biosphere-atmosphere interface over the Shanghai region in China. Phase 1 of this study, described in this report, generates input parameters for this model based on a time series of actual and derived parameters. Atmospheric forcing data are generated on an hourly temporal resolution based on a 20-year series of monthly and daily averages. Surface data, including land cover/land use and soil information, are generated ...
In this work, effects of coolant chemistry, including concentrations of chloride ions and ethylene glycol and addition of various ions, on corrosion of 3003 Al alloy were investigated by electrochemical impedance spectroscopy measurements and scanning electron microscopy characterization. In chloride-free, ethylene glycol-water solution, a layer of Al-alcohol film is proposed to form on the electrode surface. With the increase of ethylene glycol concentration, more Al-alcohol film is formed, resulting in the increase in film resistance and charge-transfer resistance. In the presence of Cl- ions, they would be involved in the film formation, decreasing the stability of the film. In 50% ethylene glycol-water solution, the threshold value of Cl- concentration for pitting initiation is within ...
This paper deals with two common problems and then considers major aspects of chemistry in the atmospheres of Mars and Venus. (1) The atmospheres of the terrestrial planets have similar origins but different evolutionary pathways because of the different masses and distances to the Sun. Venus lost its water by hydrodynamic escape, Earth lost CO"2 that formed carbonates and is strongly affected by life, Mars lost water in the reaction with iron and then most of the atmosphere by the intense meteorite impacts. (2) In spite of the higher solar radiation on Venus, its thermospheric temperatures are similar to those on Mars because of the greater gravity acceleration and the higher production of O by photolysis of CO"2. O stimulates cooling by the emission at 15@mm in the collisions with CO"2. ...
We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of waterchemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing occurrence of acid-sensitive aquatic macrophyte species, and the recent appearance of juvenile (<1 year old) brown trout in some of the more acidic flowing waters. Changes are often shown to be directly linked to annual variations in acidity. Although indicative of biological improvement in response to improving waterchemistry, 'recovery' in most cases is modest and very gradual. While specific ecological recovery endpoints are uncertain, it is likely that physical and biotic ...
Based on the IAPWS technical guidance on ''Instrumentation for Monitoring and Control of Cycle Chemistry for Steam-Water Circuits of Fossil-Fired and Combined Cycle Power Plants,'' the latest situation regarding instrumentation for nuclear power plants is discussed. As a result of the discussion, it is concluded that: (1) Reliable and safe operation of plants is established by the application of suitable chemical conditions in plant cooling systems, which should be supported by the selection of suitable control targets for monitoring and by the application of reliable instruments. (2) The minimum level of key instrumentation consists of on-line as well as off-line instruments for monitoring the key parameters: - on-line: pH, conductivity, cation conductivity, O{sub 2} and H{sub 2} concentrations, electrochemical corrosion potential; - off-line: radioactive nuclides ({sup 60}Co, {sup 58}Co, {sup 131}I, etc.), ...
Surface study techniques were used to investigate films on Type 304 stainless steel which were formed during exposure to high purity water at 288"0C. The results indicated that the film chemistry depended strongly upon the concentration of the dissolved O_2 in the water. Films formed in water having 8 ppm O_2 were stoichiometric mixed oxides; whereas those formed in water with 10 ppb O_2 were highly defective oxyhydroxides. The latter films are not as protective as the stoichiometric oxides. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to investigate the films. (Auth.).
ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.
ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory during FY94 to characterize possible contaminant movement out of Area G through surface-water and sediment runoff. These samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. Ten metals were also analyzed on selected soils using analytical laboratory techniques. All radiochemical data are compared with analogous samples collected during FY 93 and reported in LA-12986. Baseline concentrations for future disposal operations were established for metals and radionuclides by a sampling program in the proposed Area G Expansion Area. Considering the amount of radioactive waste that has been disposed at Area G, there is evidence of only low concentrations of radionuclides on perimeter surface soils. Consequently, little radioactivity is leaving the confines of Area G via the ...
The principal types of corrosion are presented which can occur in CANDU steam generator. There are also presented the operation conditions, the specifications referring to the waterchemistry and the construction materials of Steam Generator, the factors that have a great influence on the corrosion behaviour during the whole exploitation period of this equipment. The most important elements of CANDU Steam Generator ageing management program are also discussed. (R. P.)
The degradation of chlorinated solvents by reduction at the surface of zero-valent metals and bimetallic systems has emerged as an important approach to the in-situ remediation of ground water. Reduction by iron metal was studied in batch and column systems to develop a mechanistic understanding of the reaction chemistry and to determine the factors that affect dechlorination rate and long term performance in field applications.
Various electrochemical techniques are available to continuously monitor corrosion in conditions simulating those on the secondary side of PWR steam generators. This paper reviews those electrochemical techniques which are potentially useful to measure denting in tube-support crevices in situ. Attention is also given to corollary needs for monitoring the waterchemistry which leads to corrosive attack. Finally some suggestions are offered for corrosion monitoring in autoclaves, model boilers and operating steam generators.
The application of airborne sensors for providing environmental assessment and monitoring of a test site in an open cast mining area that is part of a lignite deposit in central Germany is described. Hyperspectral remote sensing data from three different sensors were tested. The hyperspectral scanner data was suitable for classification of different sediments and vegetation types and the waterchemistry of residual mining lakes. Summary form only. 1 tab.
The chemical composition and evolution of formation waters associated with gas production in the Palm Valley field, Northern Territory, has important implications for reservoir management, saline water disposal, and gas reserve calculations. Historically, the occurrence of saline formation water in gas fields has been the subject of considerable debate. A better understanding of the origin, chemical evolution and movement of the formation water at Palm Valley has important implications for future reservoir management, disposal of highly saline water and accurate gas reserves estimation. Major and trace element abundance data suggest that a significant component of the highly saline water from Palm Valley has characteristics that may have been derived from a modified evaporated seawater source such as an evaporite horizon. The most dilute ...
In this paper the thermal design of a horizontal steam generator for the Indian PHWR nuclear power plant is described. The main attraction is absence of tube sheet and use of stainless steel 'U' tubes. It is emphasised that with appropriate waterchemistry it is possible to use stainless steel tubes, which is many times cheaper than the Incoloy tubes used elsewhere. The design approach, applicable equation for the design and the results of computation in the form of heat transfer area and some important dimensions of the steam generator are presented.
This report discusses the UTR-10 reactor at Iowa State University which went critical on low enriched uranium (LEU) fuel on August 14, 1991. However, subsequent to the criticality experiments the fuel plates started to discolor. In addition, roll pins used to lift the fuel assemblies were discovered to be cracked. It was determined that these problems were due to chemical agents in the primary coolant water. The roll pins were replaced by solid stainless steel pins. The primary coolant was replaced and the reactor is currently in operation. Surveillance specimens will be used to monitor any possible future discoloration. The high enriched fuel (HEU) is being prepared for eventual shipment to a high enriched fuel receiving facility.
This report discusses the UTR-10 reactor at Iowa State University which went critical on low enriched uranium (LEU) fuel on August 14, 1991. However, subsequent to the criticality experiments the fuel plates started to discolor. In addition, roll pins used to lift the fuel assemblies were discovered to be cracked. It was determined that these problems were due to chemical agents in the primary coolant water. The roll pins were replaced by solid stainless steel pins. The primary coolant was replaced and the reactor is currently in operation. Surveillance specimens will be used to monitor any possible future discoloration. The high enriched fuel (HEU) is being prepared for eventual shipment to a high enriched fuel receiving facility.
Flow Accelerated Corrosion (FAC) of Carbon Steel (CS) piping has been one of main issues in Light-Water Nuclear Reactor (LWRs). Wall thinning of CS piping due to FAC increases potential risk of pipe rupture and cost for inspection and replacement of damaged pipes. In particular, corrosion products generated by FAC of CS piping brought steam generator (SG) tube corrosion and degradation of thermal performance, when it intruded and accumulated in secondary side of PWR. To preserve SG integrity by suppressing the corrosion of CS, High-AVT chemistry (Feedwater pH9.8#+-#0.2) has been adopted to Tsuruga-2 (1160 MWe PWR, commercial operation in 1987) in July 2005 instead of conventional Low-AVT chemistry (Feedwater pH 9.3). By the High-AVT adoption, the accumulation rate of iron in SG was reduced to one-quarter of that under conventional Low-AVT. As a result, a tendency to degradation of the SG thermal efficiency was improved. On ...
The United States Department of Energy (U.S. DOE) has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation protection monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the U.S. DOE and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis in order to accurately assess radiation doses resulting from the ingestion and uptake of fallout radionuclides contained in locally grown foods. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands including Rongelap Atoll (Figure 1). These facilities are operated and ...
A large amount of industrial water is used for cooling the various process fluids in the petroleum purification factories as well as petroleum chemistry factories. Consequently, a lot of heat exchangers as the necessary constitutional instruments are made of carbon steel. Due to the most of the corrosions of the carbon steel occurring in such cooling water systems are pitting corrosions, the inhibition thereof is extremely important for the elongation of the life of the plants and the stable operation. In this paper, the influences of water quality fractions on pitting corrosion of carbon steel in cooling water circumstance are examined aiming at the fouling in the cooling water. The fouling in the cooling water does not only increase the amount of occurrence of pitting corrosion but also accelerates the progress of pitting corrosion ...
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.)
The objective of the C-E/EPRI project, ''Alternative Steam Generator Materials and Designs,'' was to evaluate the corrosion behavior of contemporary or alternative steam generator materials under prototypic design and secondary fault (high contaminant) water conditions. Two model steam generators built with various support materials and designs were tested under representative thermal and hydraulic conditions. One model operated under seawater faulted all-volatile treatment (AVT) secondary waterchemistry conditions. The other model operated under acidified fresh water faulted AVT conditions. This presentation focuses on the tube support and tubesheet corrosion results obtained by destructive examination of both models.
The Alloy 800 tubes used in CANDU 6 steam generators have not experienced significant corrosion damage to date, which may be attributed to successful waterchemistry control strategies. However, it is known that Alloy 800, like other steam generator (SG) tubing materials, is not immune to corrosion, especially pitting, under some plausible but off-specification operating scenarios. Electrochemical measurements provide information on corrosion susceptibility and rate, which are known to be a function of waterchemistry. Using laboratory data in combination with chemistry monitoring and diagnostic software it is possible to assess the impact of plant operating conditions on SG tube corrosion for plant life management (PLIM). In this context, this paper discusses the results of electrochemical measurements made to elucidate the corrosion behaviour of Alloy 800 SG tubes under conditions ...
Irradiation-assisted stress corrosion cracking (IASCC) of several types of BWR field components fabricated from solution-annealed austenitic stainless steels (SSs), including a core internal weld, were investigated by means of slow-strain-rate test (SSRT), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), and field-emission-gun advanced analytical electron microscopy (FEG-AAEM). Based on the results of the tests and analyses, separate effects of neutron fluence, tensile properties, alloying elements and major impurities identified in the American Society for Testing and Materials (ASTM) specifications, minor impurities, waterchemistry, and fabrication-related variables were determined. The results indicate strongly that minor impurities not specified by the ASTM-specifications play important roles, probably through a complex synergism with grain-boundary Cr depletion. These impurities, typically associated with steelmaking ...
BackgroundSurveillance data allow for analysis, providing public health officials and policy-makers with a basis for long-term priorities and timely information on possible outbreaks...Full Text Available
Objectives. We investigated increases in diarrheal illness detected through syndromic surveillance after a power outage in New York City on August 14, 2003.Methods....Full Text Available
BackgroundDengue fever is a mosquito-borne illness that places significant burden on tropical developing countries with unplanned urbanization. A surveillance system using Google...Full Text Available
In the heat exchangers of power plants, scale deposition may occur, especially at the leading edge of contraction. The growth of scale can lead to an increase in pressure and cause oscillation of the water level. In our previous study, the dependence of flow on contraction geometry was analyzed numerically and empirically. It was shown that the contraction ratio of hydraulic diameter of the flow path contributed greatly to the difference in pressure drop and turbulent kinetic energy at the leading edge of the flow path. In this study, the effect of contraction geometry and flow rate on scale adhesion was studied in AVT chemistry at 270degC using a high-velocity scale-adhesion test loop. The differential pressure and the amount of scale deposited due to scale adhesion at the leading edge of the flow path increased more in a quatrefoil-type flow path than in drill-type flow path. The differential pressure and the amount of scale deposited also ...
The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to ...
Fatigue damage occurs in general when a boiler tube is subject to repeat cyclic or fluctuating loading although the stress produced is below the material yield strength. The types of fatigue damage include, e.g., corrosion, thermal, mechanical, vibration, and creep fatigue. It is important to determine which form of fatigue is active, because measures to avoid repeat failures differ as the case arises. In this lesson, the focus is exclusively on corrosion fatigue. Corrosion fatigue occurs by the combined synergistic actions of cyclic loading and a corrosive environment. It is a discontinuous process with crack initiation and growth during transient periods. The excessive stresses may be caused during boiler operation by the restraint at tube attachments and by load changes (in particular during cold starts or forced cools) or during shutdown or restart of circulation boilers by thermal stratification of water along the tube length. Poor water ...
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.
Aluminum electrolytic capacitors are presently not allowed on NASA missions because they outgas water and organic vapors, as well as H2. As a consequence, much larger and heavier packages of tantalum capacitors are used. A hermetically sealed aluminum capacitor has been developed under NASA-MSFC SBIR contracts. This capacitor contains a nongassing electrolyte that was developed for this application so internal pressure would remain low. Capacitors rated at 250 to 540 V have been operated under full load for thousands of hours at 85 and 105 C with good electrical performance and low internal pressure. Electrolyte chemistry and seal engineering concepts will be discussed.
Vector-borne infections (VBI) are defined as infectious diseases transmitted by the bite or mechanical transfer of arthropod vectors. They constitute a significant proportion of the global infectious...Full Text Available
Surveillance of a population, such as a weapon stockpile, is needed to discover manufacturing defects as well as deterioration as the population ages. This article considers the risks of sampling rates for surveillance from three perspectives: detection probability of defects in a proportion of a population with pass/fail data, detection of a trend in a defective proportion of the population with pass/fail data, and detection of a trend with quantitative degradation measurements. Understanding of these risks will help the decision maker choose a sampling rate to protect against such problems of a specified size at a tolerable risk.
The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the waterchemistry to decrease these risks are discussed. A special focus is put on zinc waterchemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet ...
The development of colorimetry and spectroscopy in the nineteenth century is described. An account is given of the application of their techniques to biological chemistry during that period.
In recent years intergranular stress corrosion cracking has occurred world-wide in the shrink-fitted discs of low pressure turbine rotors made of low alloy steels. Only in a few cases steam impurities such as NaOH, Na_2CO_3, Na_2SO_4, H_2S or NaCl, which initiate SCC, could be found. To clarify the SCC-behaviour experiments on turbine disc steels with different chemical compositions and yield strength were performed in high purity water. The results show, that chemical composition has no effect on the crack initiation. Under high purity water conditions no crack initiation due to stress corrosion cracking is observed on the steel with a yield strength of 850 N/mm"2. On the steel with a yield strength of 1250 N/mm"2 which is not used in service, crack initiation occurs in pure water. But if sharp cracks already exist, crack propagation occurs in both cases. The investigations showed, that stress corrosion cracking of turbine ...
Internal hydrological processes in suburban watersheds and their effects on water quality warrant investigation. Instrument clusters (throughfall collectors, suction lysimeters, monitoring wells, and shallow and deep piezometers) were installed at several locations within three small (50 - 70 ha) watersheds (one forested, two with different degrees of suburban development) in the Croton Watershed, southeastern New York. Biweekly and storm samples were analyzed for base cations, selected anions, and DOC over a one-year period. The topographic index (TI) quantified landscape position; flowpath analyses determined degree of development at each cluster, using % impervious cover as the metric. Water quality degradation was observed in sites with medium and high TI values; no such effect was observed along the ridges, i.e., low TI values. At medium TI values, areas with more than 5% impervious had degraded water quality. At high ...
Many electric power utilities are currently employing machine condition monitoring technologies as a means of reducing forced outages and controlling repair costs. These condition monitoring technologies are a set of {open_quotes}tools{close_quotes} to help maintenance and operations personnel identify and repair machinery problems before catastrophic failure occurs. In this way, the analysis of this data becomes a vital link in the daily operation of the plant. Machinery vibration analysis, machinery balancing and alignment, motor current testing, periodic thermography surveys, analysis of lubrication oil samples, performance monitoring, chemistry monitoring, ultrasonic leak detection surveys, and non-destructive inspections are some of the technologies available to perform this condition monitoring. However, even for a small or medium size plant, the sheer volume of data provided by applying all or some of these technologies can be staggering, not to mention the ...
A large matrix of simple alloys and complex commercial type steels was irradiated over a range of fluxes at 60 FC up to a fast fluence of about 3 x 10"2"2 n/m"2. Combined with data in the literature, these results show a negligible effect of flux on irradiation hardening in the range of 2 x 10"1"3 to 5 x 10"1"8 n/m"2-s. This observation lends indirect support to the proposal that the accelerated embrittlement in the High Flux Isotope Reactor surveillance steels was due to an anomalously high level of damage from gamma rays. A weak dependence of hardening on a number of elements, including copper, nickel, phosphorus, molybdenum and manganese, can be described by a simple empirical chemistry factor. Particular combinations of elements resulted in hardening differences of up to about 60% in the complex commercial type steels and up to about 100% in simple model alloys. Direct effects of microstructure appear to be minimal. Hardening varies with ...
Since 1975 All Volatile Treatment (AVT) has been the preferred method for controlling the secondary system operating environment in Westinghouse PWR plants. However, since AVT provides no buffering action against corrodent species present in the water as trace contaminants, utilities have initiated programs which combine control of contaminant ingress with total steam generator sludge management. The earliest applications of boric acid, to control denting type corrosion, began in 1978 and have continued up to the present time. Boric Acid has also been added as an inhibitor for SCC/IGA type corrosion since 1985. There are now approximately 30 plants operating with boric acid or boric acid/morpholine chemistry in the secondary system, and a growing number of plants where morpholine is being used as an additive to maintain pH and reduce iron transport attributable to erosion/corrosion. The impact of these modifications in the operating ...
Summary This third paper, in a three-part CE series on the preventions of infection in patients with chronic kidney disease, focuses on surveillance and auditing of healthcare-associated infections within the renal care environment. The last decade has seen an increased awareness of the threat to patient safety from healthcare-associated infection (HCAI) and the emergence of multi-drug resistance organisms. Effective HCAI prevention strategies include adequate governance structures, access to expert advice, adherence to standard and transmission-based precautions, minimising the use of invasive medical devices, and surveillance. Surveillance data can be collected using outcome (e.g. infection) and/or process (e.g. hand hygiene compliance audit) measures. Establishing a surveillance program...
The Model of Acidification of Groundwaters in Catchments (MAGIC) was used to simulate the impact of acidifying deposition and future recovery at the Gaardsjoen Covered Catchment Experiment, at a number of hypothetical stations defined by statistical variation of the Gaardsjoen data and at 20 forest monitoring sites in Southern Sweden. For the future predictions a decrease of sulphur deposition of more than 70% was assumed. This assumption is based on a full implementation of the agreements made under the second sulphur protocol from 1994. The modelled impact of reduced deposition on the soils and on the runoff waters was discussed. To complement the discussion on long-term trends in future run-off chemistry, data from Gaardsjoen has been used to asses the risk for short-term acid runoff episodes 26 refs, 23 figs, 7 tabs
Titanium stabilized austenitic steel is sensitive to SCC in the secondary water under the horizontal steam generator operating conditions. SCC was observed under crevice conditions both at the primary collector flanges and the heat exchange tubes. In the crevice environment sulfates and chlorides as aggressive species and silicates and alumino-silicates as ''non-aggressive'' species are present in significant amounts. Local waterchemistry parameters were evaluated using the MULTEQ Code. SCC experiments were carried out by rising displacement tests ar 275 deg C in an environment simulating the crevice conditions. Crack growth rate and K{sub IS}8C{sub C} were determined for the environment where contents of some species were from 10{sup 2} to 10{sup 4} times higher than in blowdowns. (authors)
Titanium stabilized austenitic steel is sensitive to SCC in the secondary water under the horizontal steam generator operating conditions. SCC was observed under crevice conditions both at the primary collector flanges and the heat exchange tubes. In the crevice environment sulfates and chlorides as aggressive species and silicates and alumino-silicates as ''non-aggressive'' species are present in significant amounts. Local waterchemistry parameters were evaluated using the MULTEQ Code. SCC experiments were carried out by rising displacement tests ar 275 deg C in an environment simulating the crevice conditions. Crack growth rate and K_I_S8C_C were determined for the environment where contents of some species were from 10"2 to 10"4 times higher than in blowdowns. (authors)
Developed under the PN II Project 71-009 - MONA, the pre-operational monitoring program of the LIL waste disposal site presented in this paper covers the main elements requested for a continuous improvement of site characterization and safety assessment, as well as for the set up of the baseline data requested for the future operational and post-operational monitoring and surveillance. These elements are: vadose and saturated zones hydrogeology, surface erosion, meteorology and radionuclides content in waters, soil and biota. Pairs of TDR (Time Domain Reflectometry) and pressure sensors, coupled with a meteorological station have been installed on site for the continuously measurement of the water content and matric potential changes due to the climate variations. The data will be used to follow the water balance, the pores water velocity and to calculate the infiltration rate. A ...
Experience of the Westinghouse Water Reactors Division with indoctrination and training of quality engineers includes training of personnel from Westinghouse divisions in the USA and overseas as well as of customers' personnel. A written plan is prepared for each trainee in order to fit the training to the individual's needs, and to cover the full range of information and activities. The trainee is also given work assignments, working closely with experienced quality engineers. He may prepare inspection plans and audit check lists, assist in the preparation of QA training modules, write procedures, and perform supplier surveillance and data analyses, or make special studies of operating systems. The trainee attends seminars and special courses on work-related technical subjects. Throughout the training period, emphasis is placed on inculcating an attitude of team work in the trainee so that the result of the training is the achievement of both ...
This report focuses on air quality at the Nevada Test Site (NTS) for 1994. A general description of the effluent sources are presented. Each potential source of NTS emissions was characterized by one of the following: (1) by monitoring methods and procedures previously developed at NTS; (2) by a yearly radionuclide inventory of the source, assuming that volatile radionuclides are released to the environment; (3) by the measurement of tritiated water concentration in liquid effluents discharged to containment ponds and assuming all the effluent evaporates over the course of the year to become an air emission; or (4) by using a combination of environmental measurements and CAP88-PC to calculate emissions. Appendices A through J describe the methods used to determine the emissions from the sources. These National Emission Standards for Hazardous Air Pollutants (NESHAP) emissions are very conservative, are used to calculate the effective dose equivalent to the ...
Individual monitoring of personal exposure to inhalation of uranium oxides throughout the manufacture of fuel for pressurized water reactor (PWR) includes lung gamma-spectrometry, fecal analysis and urine analysis. Examination of the results shows the following: internal exposure is the consequence of repeated intake incidents as revealed by early peaks of urinary and particularly fecal elimination; a shift is often observed with the results of aerosol concentration measured through air collectors; the measured variations of uranium lung incorporations are relatively fast (apparent mean period 165 d). Correct evaluation of the effective dose equivalent from inhalation requires further information concerning the aerosol size distribution at work stations, the physico-chemical characteristics of the product leading to an estimate of its actual biological solubility, and the measurement of the fraction of aerosol liable to intake with an individual portable collector.
Over the past few years, NPCIL has performed comprehensive Level-1 Probabilistic Safety Assessment (PSA) for a 220 MWe Pressurised Heavy Water Reactor (PHWR) at Kakrapar Atomic Power Station (KAPS) and for the first 540 MWe PHWR at Tarapur Atomic Power Project (TAPP- 3 and 4). The major objective of these PSAs was to present an integrated picture of the safety of the plant to identify and understand key plant vulnerabilities. As a result of the availability of these PSAs, there is a desire to use them to operate the plants in the most efficient manner practicable. In recent years, the operation of Indian Nuclear Power Plants has been characterized by improved availability/capacity factors and reduced forced outages. Frequency of planned outages is also being reduced. In order to achieve this, the PSAs are now being used as an engineering tool for optimization of Technical Specifications with regard to Allowed Outage Time (AOT) and Surveillance ...
The trace element selenium (Se) is required in the production of enzymes that protect mammalian cells from oxidative damage due to the byproducts of aerobic respiration. Its deficiency in livestock results in the nutritional muscular dystrophy called white muscle disease. This especially affects juveniles in the preweaning period. Symptoms have also been reported in wild herbivores on low-Se forage, and their appearance may be episodic, suggesting temporal variations in Se uptake by plants. Here, we report variations in selenium concentrations in Carex spp. sedges used as forage by bighorn sheep (Ovis canadensis) on summer range in the Wyoming, Wind River Mountains, and correlate those variations with soil conditions that affect the bioavailability of selenium. Variations in available Se are explained based upon the known oxidation/reduction chemistry of the element. It is concluded that water-saturated, alpine soils provide conditions suitable ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that {sup 139}Ce and {sup 51}Cr and {sup 110m}Ag are strongly sorbed to suspended particle, ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that "1"3"9Ce and "5"1Cr and "1"1"0"mAg are strongly sorbed to suspended particle, while ...
This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project has examined the fundamental chemistry of plutonium that affects the integration of hydrothermal technology into nuclear materials processing operations. Chemical reactions in high temperature water allow new avenues for waste treatment and radionuclide separation.Successful implementation of hydrothermal technology offers the potential to effective treat many types of radioactive waste, reduce the storage hazards and disposal costs, and minimize the generation of secondary waste streams. The focus has been on the chemistry of plutonium(VI) in solution with carbonate since these are expected to be important species in the effluent from hydrothermal oxidation of Pu-containing organic wastes. The authors investigated the structure, solubility, and stability of the key ...
The verification test program on zinc injection applicability to Japanese BWRs was started in 1997. Laboratory tests using high temperature water loops under BWR reactor water conditions are in progress. This paper is an interim report on results obtained so far. Co-58 and Zn-65 were simultaneously used in the Co radioactivity buildup test to evaluate zinc injection suppression effects towards cobalt deposition on pre-oxidized stainless steel. The following results were obtained. The Co deposition was suppressed effectively by Zn injection, even when there was a pre-oxide film. For the test piping that had the pre-oxide film formed under the NWC (normal waterchemistry) condition, when soaked under the HWC (hydrogen waterchemistry) condition a large amount of Co-58 was taken into a small part of the inner layer. The distribution ratio of Co-58 in the inner ...
The titanium stabilized austenitic steel similar to the type of 321 is sensitive to the stress corrosion crackingunder horizontal steam generator operating condition. SCC was observed under crevice corrosion parameters and has resulted in the transgranular or intergranular cracking at the both, components primary collectors and heat exchange tubes. The crevice environment is characterized by aggressive impurities and 'non aggressive' compounds. Sulfates and chlorides as aggressive species and silicates and alumino-silicates as 'non aggressive' species on the other hand are present in significant amount in the crevice environment under operating condition. Local waterchemistry parameters were evaluated with MULTEQ Code. As input data the measured operational values of local and bulk environments have been used. The determined parameters were compared with the results of thread hole environment analyses and ...
The primary goal of this project is to increase the availability and ease of access to critical data on the Mesaverde and Dakota tight gas reservoirs of the San Juan Basin. Secondary goals include tuning well log interpretations through integration of core, waterchemistry and production analysis data to help identify bypassed pay zones; increased knowledge of permeability ratios and how they affect well drainage and thus infill drilling plans; improved time-depth correlations through regional mapping of sonic logs; and improved understanding of the variability of formation waters within the basin through spatial analysis of waterchemistry data. The project will collect, integrate, and analyze a variety of petrophysical and well data concerning the Mesaverde and Dakota reservoirs of the San Juan Basin, with particular emphasis on data available in the areas defined as tight gas ...
Manganese is a common contaminant of mine water and other waste waters. Due to its high solubility over a wide pH range, it is notoriously difficult to remove from contaminated waters. Previous systems that effectively remove Mn from mine waters have involved oxidising the soluble Mn(II) species at an elevated pH using substrates such as limestone and dolomites. However it is currently unclear what effect the substrate type has upon abiotic Mn removal compared to biotic removal by in situ micro-organisms (biofilms). In order to investigate the relationship between substrate type, Mn precipitation and the biofilm community, net-alkaline Mn-contaminated mine water was treated in reactors containing one of the pure materials: dolomite, limestone, magnesite and quartzite. Mine waterchemistry and Mn removal rates were monitored over a 3-month ...
Generally, Hardening and irradiated brominating phenomena are occurred in the reactor vessel under operation conditions by atomic cavities and creation of impurity atoms which are led by high fast neutron flux. To assure the mechanical integrity of pressure vessel until the end of power plant life after monitoring the sample specimens on the vessel inside, a series of tests is performed over the retrieved surveillance capsule to examine the changes according to the plant operation in accordance with regulations. Monitoring surveillance capsules attached to neutron shield wall of outer core are consists of impact sample, tensile sample and temperature monitor
The French office for technical studies and control of big dams (BETCGB), has recently reedited the `guidebook for the control of dams in exploitation`. The aim of this document is to provide to the regional directions of industry, research and environment (DRIRE) a methodological help for their control actions of hydroelectric dams granted for exploitation. It comprises 6 chapters dealing with: the different type of dams, the inspection, the surveillance, the floods evacuation, the flood instructions, and the particular emergency plans. (J.S.)
The paper discusses the safety problems connected with the conversion to dense storage of RBMK-1000 spent fuel in reactor cooling pools and independent storage facilities. Recourse to dense storage has been made for a number of reasons, among which are the absence of spent fuel shipments from the nuclear power plant site, prolongation of storage time and a partial change in storage conditions. Increasing the storage density per unit volume of the storage facility and turning to new technical procedures (as against the basic design) call for further investigation of safety problems. The safety assessment of the dense storage mode includes: (1) Selecting a list of initiating events for design basis and unforeseeable accidents; (2) Assessing dense storage safety under normal as well as design basis accident conditions; (3) Safety analysis and development of measures to compensate for unforeseen accidents. Based on the studies performed, suggestions have been advanced concerning ...
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 waterchemistry 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 ...
A study has been performed of the initial corrosion of support structure alloys in crevices of various geometries, when galvanically coupled to alloy 600. Corrosion rates were monitored continuously by measuring the galvanic current flowing in each couple, transduced by a zero impedance ammeter. Experiments were performed in a single-pass flowing electrolyte system, with AVT water pumped through alloy 600 tubing past the orifice of each crevice. Fourteen crevices were studied simultaneously in two parallel flow arms containing seven specimens each. The steady state AVT water pH/hydrazine/oxygen concentrations were controlled by microcomputer, allowing the effect of secondary waterchemistry on the corrosion rate to be studied easily. Control of the crevice electrolyte composition was achieved by separately pumping electrolyte, at a low rate, directly into the crevices of the seven specimens in the lower ...
The deposit of radioactive corrosion products in the cooling systems of nuclear reactors becomes a serious problem for the personnel of facilities. Crud has an important role in the process of depositing radioactive corrosion products. The main components of crud are hematite, magnetite, nickel ferrite and so on, and the particles of these oxide compounds are distributed in water. Most of the behavior of crud are still not known. As for the mechanism of the production of crud, the Potter-Mann model has been proposed. However, the precipitation process of iron ions in water is unknown. The crud is defined as the particles filtered by 0.45 micrometer millipore filters. However, it is not known whether there are crud particles smaller than this size. The crud particles can be adsorbed on the filters by the surface electrochemical interaction. The adsorption of cations to crud particles was studied. The adhesion of crud particles was investigated ...
The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with particular emphasis on the transferability of the ...
... terminals, popular tourist spots, political rallies, and subway ... Dynamic scheduling of a two-class queue with ... Stochastic Processes 2nd ed. Wiley. ...
Material degradation of pressure tubes, which are the most important components in CANDU fuel channel, can only be evaluated by removing and examining them(material surveillance). This study aimed at establishment of overall evaluation technology including the evaluation of the material degradation for the integrity of pressure tubes of Wolsung units. Material tests for pressure tubes were performed as follows; (1) Evaluation on life limiting factors of pressure tubes (2) Review on leak-before-break and integrity maintenance technology of pressure tubes (3) Survey on selection criteria for tubes to be inspected and on related regulations for material surveillance (4) Analysis of material surveillance test procedure (5) Basic examinations of Wolsung unit 1 pressure tube material(TEM, texture, chemical component etc) (6) Manufacture of test equipments and test (DHCV, hydriding, grip and tensile specimen etc). 23 figs, 6 tabs, ...
The secondary side corrosion of steam generator tubes is the main degradation of components in operating power plants, strongly impacted by chemistry. This is why EDF has largely studied the chemical parameters in its 56 PWRs which might influence corrosion development. The results of 168 hideout returns of chemical species performed on the French plants allowed to draw conclusions on where chemical species are likely to concentrate in steam generators and on the influence of several contaminants on corrosion processes: sodium, chloride, phosphate, organic compounds, etc... Based on laboratory studies and plants feedback, new chemistry specifications were established and are now applied to EDF units to minimize corrosion and operating costs and to provide a good availability while maintaining an excellent safety. Boric acid is added in the secondary water of the 10 oldest units with Inconel 600 MA tubing, highly sensitive ...
The Steam Generator (SG) tubing degradation caused by corrosion and other age-related mechanisms continues to be a significant safety and cost concern for many Nuclear Power Plants (NPP). The understanding of the steam generator ageing mechanisms is the key to effective management of steam generator ageing and consists of the knowledge of steam generator materials and these one properties, stressors and operating conditions, like degradation sites and wear mechanisms. The principal types of corrosion are presented which can occur in CANDU steam generator. There are also presented the operation conditions, the specifications referring to the waterchemistry and the construction materials of Steam Generator, the factors that have a great influence on the corrosion behaviour during the whole exploitation period of this equipment. (R.P.)
The growth of an oxide interfacial layer was recently found to increase the open-circuit voltage (OCV) and efficiency by up to 60 per cent in GaAs metal-semiconductor solar cells. Details of oxidation techniques to provide the necessary oxide thickness and chemical structure and using ozone, water-vapor-saturated oxygen, or oxygen gas discharges are described, as well as apparent crystallographic orientation effects. Preliminary results of the oxide chemistry obtained from X-ray, photoelectron spectroscopy are given. Ratios of arsenic oxide to gallium oxide of unity or less seem to be preferable. Samples with the highest OVC predominantly have As(+3) in the arsenic oxide rather than As(+5). A major difficulty at this time is a reduction in OCV by 100-200 mV when the antireflection coating is vacuum deposited.
Based on the X-ray crystallographic data of Tc-complexes for brain imaging agents, geometry optimizations in vacuo of TcO-BAT, TcO-MAMA, TcO-L, L-ECD, TcN-BAT and TcN-L, L-ECD complexes are performed with Hartree-Fock method and LANL 2 DZ basis set of G98W program. Then solvation free energy for each Tc-complex mentioned above in water is calculated by polarizable continuum method (PCM) including models of CPCM and IEFPCM. The results show that solvation free energy of Tc-complex is not only an indicator of lipophilicity but also one of the important factors that influence the brain uptake
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...
Studies addressed to a deep understanding of the structure/property relationship on the near infrared (NIR)-emissive erbium-quinolinolate complexes, which are of interest for low-cost photonic systems, are reviewed. The role of the 8-quinolinolate ligand (Q), which studies also as sensitizer to overcome the weak absorptivity of lanthanide ion, is discussed. Synthetic and structural aspects are reported to revise the old assumption that these complexes are analogous in structure to AlQ3 and to point out the specificity of the lanthanide coordination chemistry. In fact depending on reaction conditions, species with high coordination numbers and differing for nuclearity and stoichiometry have been isolated and fully characterized. In some instances it has been shown that coordinated water mol...
This report presents the results of an experimental programme to determine the mass transfer and sorptive properties of selected glacial sand and clays from the Drigg Disposal Site operated by British Nuclear Fuels plc. The hydraulic conductivity of both the sand and clay has been determined and the sensitivity of this parameter to changing waterchemistry investigated. The hydrodynamic dispersion properties of the glacial sand were measured in order to aid the interpretation of column sorption experiments. The sorption of strontium and uranium from groundwater onto clay and sand samples has been studied using through-diffusion, column and batch techniques. Employing the batch technique, the effect of a series of humic acid concentrations on distribution ratios for uranium and plutonium has also been investigated. Groundwater and trench leachate were used with both clay and sand. (author).
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation waterchemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (<24...
Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. A two-year study of the effects of pH and associated waterchemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia were investigated. Leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three stream were compared. It was found that macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates ...
Spacecraft studies of the three terrestrial planets with atmospheres have made it possible to make meaningful comparisons that shed light on their common origin and divergent evolutionary paths. Early in their histories, all three apparently had oceans and extensive volcanism; Mars and Earth, at least, had magnetic fields, and Earth, at least, had life. All three currently have climates determined by energy balance relationships involving carbon dioxide, water and aerosols, regulated by solar energy deposition, atmospheric and ocean circulation, composition, and cloud physics and chemistry. This paper addresses the extent to which current knowledge allows us to explain the observed state of each planet, its planetology, climatology and biology, within a common framework. Areas of ignorance...
This summary report outlines the work that was performed to gain a more complete understanding of denting corrosion of steam generators in PWRs. Background laboratory and plant data on denting were compiled, reviewed and correlated to determine how various exposure conditions affect denting. Two high-temperature chemistry analytical models were reviewed and evaluated by experimental simulation of impurity concentration in the heat transfer and isothermal capsule tests. Simulation of impurity concentration for three cooling waters (lake, river, and cooling tower) was evaluated. The effects of species concentration (Cu/sup + +/, Cl/sup -/, O/sub 2/, and H/sup +/), contaminant thresholds (established by isothermal and heat transfer tests), and heat flux as indicated by superheat on denting were examined. A discussion of several pertinent observations and conclusions drawn from these tasks (as they pertain to plant operation) is presented.
Abstract Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X-=-1-m and...
As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead contamination on the ...
NSF-NIST Interaction in Chemistry, Materials Research, Molecular Biosciences, Bioengineering, and ... Laboratory (CSTL). Materials research is centralized in the Materials Science and Engineering ...
The chemical thermodynamic concepts used in the calculation of solubility data of silica (quartz) are presented taking into account the PVT characteristics of water. The temperature-dependence trends between the thermodynamically calculated and the experimental quartz solubility data are very similar, but the values are widely different at high temperatures. The experimental solubility, especially along the saturation curve at high temperature and thermodynamic data for silica need to be reevaluated in order to use silica chemistry to understand geological processes. There could exist a wide range of values for silica solubility at a specified temperature, depending upon the amount of water in the reaction vessel. Thus the silica contents in geothermal fluid, in general, cannot be used as a geothermometer to estimate the reservoir temperature. The derivation of a silica geothermometer needs an extra assumption about the ...
According to ICRP 60 and European-Directive 96/29, Naturally Occurring Radioactive Materials (NORM) and Technical Enriched Naturally Occurring Radioactive Materials (TENORM) have to take the radiation protection of the general population as well as of workers into account. The German radiation protection regulations stress that particularly. In connection with these regulations, various measurement programs have been and still are performed to investigate the relevant exposure paths. One of these programs is the determination of the intake of natural occurring radionuclides of the uranium decay series in individuals of the public, in exposed regions and houses and also at NORM workplaces by excretion analysis. Excretion analysis surveillance is one of the common tools for internal dosimetry. Sources of primordial radionuclides could be the ingestion of foodstuff and water and the incorporation of (mostly airborne) pollution on work places. The ...
Laboratory-based surveillance of Lyme disease in Connecticut during 1984 and 1985 identified 3,098 persons with suspected Lyme disease; 1,149 were defined as cases. Lyme disease incidence in Connecticut...Full Text Available
An automated surveillance and baseline noise signature acquisition system is being demonstrated at Sequoyah-1. A nonperturbing method is also being developed for monitoring the subcritical reactivity during initial core loading in LWRs, in fuel storage and processing facilities, and during postaccident recovery operations such as Three Mile Island-2. (DLC)
Lacustrine rocks are a significant component of many rift-valley sequences. Comparisons of both active and ancient rift valleys indicate that the lacustrine facies are commonly rich in organic matter and may be important sources for oil. For example, Holocene sediments in Lake Tanganyika and Cretaceous lacustrine rocks in west Africa contain as much as 12% and 20% TOC, respectively. The Newark Supergroup contains abundant lacustrine rocks. The widespread occurrence of black shales, the general similarity to known organically rich rift systems, and a few isolated geochemical analyses have caused some speculation about the potential of the Newark Supergroup to be an effective source of oil and gas. Sufficient geochemical analyses are available from lacustrine rocks in the Newark, Connecticut, and Deep River basins to evaluate their potential as hydrocarbon sources. In general, both the quantity and quality of organic matter in these rocks are less than that required for potential source ...
Stress corrosion cracking tests in constant extension rate tensile (CERT) and constant load tensile (CLT) tests were conducted on Ni-xCr- 9Fe-yC in Ar, water, and a LiOH-boric acid solution. Cr and C improve the resistance of Ni-base alloys to IG cracking in both Ar and water at 360C. Since creep plays a role in IG cracking, one possible explanation for the role of the environment involves its effect on the creep. Experiments were conducted on the role of C in the deformation behavior and failure mode of Ni-16Cr-9Fe. Constant load experiments were conducted on Ni-16Cr-9Fe to determine if the CLT test is more aggressive than CERT. The electron backscattering technique in a SEM is being developed in order to extend the IG cracking studies to grain sizes typical of commercial alloys, 20-30 microns.
Stress corrosion cracking tests in constant extension rate tensile (CERT) and constant load tensile (CLT) tests were conducted on Ni-xCr- 9Fe-yC in Ar, water, and a LiOH-boric acid solution. Cr and C improve the resistance of Ni-base alloys to IG cracking in both Ar and water at 360C. Since creep plays a role in IG cracking, one possible explanation for the role of the environment involves its effect on the creep. Experiments were conducted on the role of C in the deformation behavior and failure mode of Ni-16Cr-9Fe. Constant load experiments were conducted on Ni-16Cr-9Fe to determine if the CLT test is more aggressive than CERT. The electron backscattering technique in a SEM is being developed in order to extend the IG cracking studies to grain sizes typical of commercial alloys, 20-30 microns.
The INCO ``INCOLOY 800`` trademark groups the Fe-Cr-Ni alloys containing 30 to 35% nickel, 19 to 23% chromium, 0,15 to 0,60% aluminium, 0,15 to 0,60% titanium and less than 0,10% carbon contents, used as construction materials for condenser and heat exchanger tubes. In parallel with waterchemistry control and studies aimed at reducing the residual stresses resulting from tube expansion, studies have been conducted to a better understanding of this alloy, its metallurgy and its corrosion behaviour under accurately defined fabrication and heat treatment conditions. The purpose of this paper is to present the results of a behaviour study of INDRET alloy 800 concerning isothermal relaxation and effects of the said relaxation heat treatments on alloy microstructure studied with a transmission electron-chemical method to determine the sensitiveness to intergranular corrosion, and by electrochemistry in pressurized hot water. ...
In this thesis the rate constants for a number of radical reactions in aqueous solution have been studied in a wide temperature range. The reactions of H with H_2O_2, OH and HO_2 and the reactions of HO_2 with OH, Fe"2"+ and Cu"2"+ have been studied. For each reaction rate constants have been determined as a function of temperature using the technique of high temperature, high pressure (HTP) pulse radiolysis. The rate constants were obtained by fitting a kinetic computer model to the experimental data. From an Arrhenius plot the activation energy of each reaction was determined. The data determined in this way are important for modeling of radiolysis in nuclear light water reactors. A previously developed model for calculation of the effect of water radiolysis products on oxidation and dissolution of spent nuclear fuel has been improved. In the new model, called TraRaMo, simultaneous transport by diffusion and chemical reactions induced by ...
A workshop on radioactivity in coal use was held on September 15 through 17, 1981, under the auspices of the US Department of Energy, Office of Environmental Programs, and the Los Alamos National Laboratory. The purpose of the workshop was to identify research issues associated with radioactivity resulting from the use of coal for electric power generation. The concensus of the 10 scientists participating in the workshop was that a moderate to strong need exists for research in solubility of fly ash in different fluids and for determination of radioactivity in construction materials. Several additional research issues were identified but were given a lower priority. Summaries of each presentation are included. Titles are: some effects of coal combustion on the radiation environment; radionuclides in western coal at Mound; low-level radiation in coals utilized and ashes produced at New York State electric utilities; radioactivity from coal use - where are the problems; ...
Work at Institutt for energiteknikk (IFE) comprises both nuclear and non-nuclear activities. The main nuclear program is centered on the Halden Reactor Project. In 1958, the first Halden Reactor Project Agreement was signed by organisations representing 12 European countries. During 1994 France became a full member and associate membership was established with Russia. Accordingly, 16 countries were participating in the Project by the end of the year. The objectives have evolved from being simply a demonstration of the operation of a boiling heavy-water reactor to becoming a substantial research and development programme covering the domains of human-machine interaction, fuel behaviour, materials testing, waterchemistry, and instrumentation. In 1994, significant progress was achieved in all of the areas addressed by the project, including the re-instrumentation of irradiated fuel rods, fission gas release, ...
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 ...
Rapid corrosion of PWR steam generator carbon steel support structures and consequential denting of steam generator tubes led to investigation of alternative support designs and materials. In recent designs of steam generators the carbon steel drilled hole tube support plate has been replaced by one of quatrefoil or trefoil shape to minimize the contact area. These plates are now made of more corrosion resistant chromium steel (approx. 12%Cr) to ensure that they are less vulnerable to attack in the event of adverse boiler waterchemistry. This study was initiated to examine the corrosion behavior of a range of chromium steels in the acid chloride environments characteristic of tube/support plate crevices under adverse boiler water conditions. Objectives of the study were to: 1) determine the relative susceptibility of candidate tube support plate steels to acid chloride corrosion; 2) investigate the corrosion product ...
Short review of works on astatine chemistry carried out by authors for the last thirty years are done. Discovery of single-charged cation stable in aqueous solutions is predominant attainment of authors in the branch of inorganic chemistry. The first successful synthesis of heptavalent astatine compounds is a new and significant result of the last years. New direction in the chemistry of the fifth halogen is organic chemistry of astatine
In January 1994, a 6.7 magnitude earthquake in southern California ruptured a pipeline releasing approximately 4,200 barrels of blended San Joaquin Valley crude oil. A smaller volume entered the Santa Clara River and flowed 25 km downstream to an emergency containment dam. Ruptured water mains and chlorinated discharges from a damaged sewage treatment plant also affected water quality in the river. Quantitative injury assessment studies were initiated within days of the spill and included water/sediment chemistry, benthic macroinvertebrate community analyses and aquatic toxicity tests. Water quality values for TPH, BTEX, and chlorine ranged from nondetectable to 78 mg/l (TPH), nondetectable to 5.4 microg/l (total BTEX constituents) and nondetectable to 600 microg/l (residual chlorine) within 72 hours of the spill. Ammonia concentrations ranged from nondetectable to 12.1 mg/l within ...
Stabilized austenitic steels can suffer intercrystalline stress corrosion cracking under BWR water conditions. This experience of the last three years, which is important for German nuclear power station technology, has resulted from the discovery of cracks, which were detected in pipework made from titanium-stabilized 1.4541 charged with hot reactor water in six boiling water reactors and in core components made from niobium-stabilized 1.4550 of one BWR plant. Remedies to the pipework have been found by applying optimized materials and fabrication procedures and also by improving waterchemistry conditions. (orig.) [Deutsch] Stabilisierte austenitische Staehle koennen unter SWR-Reaktorwasser-Bedingungen interkristalline Spannungsrisskorrosion (IKSpRK) erleiden. Diese fuer die deutsche Kernkraftwerkstechnik bedeutsame Erfahrung der letzten drei Jahre ergab sich aus Rissbefunden, die ...
Hydrogen injection into the reactor water has been applied to many BWR power stations. Since hydrogen injected accelerates recombination of oxidant generated by water radiolysis, oxidant concentration, such as dissolved oxygen concentration in reactor water can be reduced. As the result of the reduction of oxidant concentration, Electrochemical Corrosion Potential (ECP) at the surface of structural material can be lowered. Lowered ECP moderates Stress Corrosion Cracking (SCC) sensitivity of structural materials, such as stainless steels. As usual, hydrogen injection system begins to work after the plant start-up is finished, when the condition of normal operation is established. Accordingly, Hydrogen WaterChemistry (HWC) does not cover all the period of plant operation. As far as SCC crack growth is considered, loss of HWC during plant start-up does not result in significant crack ...
As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead contamination on the ...
As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead contamination on the ...
Surveillance and maintenance (S & M) of 75 sites were conductd by the Remedial Action Section for the Environmental Restoration Program for surplus facilities and sites contaminated with radioactive materials and/or hazardous chemicals. S & M activities on these sites were conducted from the end of their operating life until final facility disposal or site stabilization. The objectives of the Waste Area Grouping S & M Program are met by maintaining a program of routine S & M as well as by implementing interim corrective maintenance when deemed necessary as a result of site surveillance. This report briefly presents this program`s activities and includes tables indicating tank levels and dry well data for FY 1991.
Surveillance and maintenance (S M) of 75 sites were conductd by the Remedial Action Section for the Environmental Restoration Program for surplus facilities and sites contaminated with radioactive materials and/or hazardous chemicals. S M activities on these sites were conducted from the end of their operating life until final facility disposal or site stabilization. The objectives of the Waste Area Grouping S M Program are met by maintaining a program of routine S M as well as by implementing interim corrective maintenance when deemed necessary as a result of site surveillance. This report briefly presents this program's activities and includes tables indicating tank levels and dry well data for FY 1991.
For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ?-lactams (four penicillins, three penicillins in combination with ?-lacta...
This association participated in different working groups: North Cotentin radioecology group, groups of expertise on the uranium mines of Limousin, executive committee for the management of the post accidental phase of a nuclear accident or a radiological emergency situation, radioactive waste management, radiological surveillance of the territory, radiation protection mission by the Asn, radiological surveillance of the environment of the Chinon nuclear power plant, study of the presence of {sup 235}U around the site of Brennilis, study of the radioactive waste management at the Manche plant, radiological surveillance of the Cyceron cyclotron at Caen, Aurengo commission on the consequences in France of the Chernobylsk accident. Actions of information, regular publications, meeting with public are also a part of the work of this association. (N.C.)
A technique involving shifting of core fuel loadings was investigated as a method for reducing the neutron flux at points of high damage accumulation in the pressure vessel wall of a light water reactor. Calculations were run for six types of commercial generic PWR. Information is provided on the progress being made to develop and apply the Solid State Track Recorder (SSTR) method for in-situ in- and ex-vessel measurements of neutron exposure parameter values, such as fluence (E > 1.0 MeV) and dpa in iron. A new technique of quantitative track counting, the Buffon needle method, is advanced. It is based on random sampling of the SSTR surface. A desensitized etching technique was developed that resulted in an excellent differential energy response for alpha particles in the 3- to 14-MeV energy range. The optical efficiency of Muscovite mica for manual fission track counting is being redetermined to form a data base for comparison with automatic counting systems. ...
The condition of spent nuclear fuel (SNF) in wet storage at ten Soviet-designed research reactors has been assessed in the light of international experience in order to identify any associated safety issues. These reactors use Al-clad UO2-Al or U-Al alloy dispersion fuels of ?20% enrichment that were fabricated in Russia; the reactors have been in operation since 1955-70. Although originally sent for reprocessing, much of the SNF generated over the last 25-30 years has been stored in fuel storage pools (FSPs) of variable water quality. The external condition of wet-stored SNF assemblies from the reactors surveyed varied from significant failure due to galvanic corrosion that was driven by poor water quality, through gradual pitting caused by slightly impure water, to a stable condition of no observable change in the oxidized Al alloy surface of the irradiated fuel. SNF stability in wet storage seems to depend on three ...
The Creating Wetlands in the Oil Sands Reclamation workshop was held to solicit expert views from leading authorities in a number of disciplines related to the creation and study of wetlands, as well as to investigate challenges in the creation of wetlands in reclaimed oil sands landscapes. This document provided a detailed transcript of each presentation and all discussions that followed. The workshop was divided into 5 sessions: (1) wetlands background information; (2) groundwater conditions and boreal wetlands; (3) creating wetland types; (4) wildlife in boreal wetlands and traditional environmental knowledge; and (5) treatment wetlands. An expert panel overview provided presentations on post-mining restoration of boreal landscapes in oil sands regions; the creation of fens, marshes and shallow water wetlands at oil sands sites and the restoration of damaged peatlands. A outline of the physical scale of the oil sands mining disturbances was provided during the ...
We describe the synthesis and characterization of superparamagnetic iron oxide nanoparticle based heavy metal sorbents with various surface chemistries that demonstrate an excellent affinity for the separation of heavy metals in contaminated water systems (i.e. spiked Columbia river water). The magnetic nanoparticle sorbents are prepared from an easy to synthesize iron oxide precursor, followed by a simple, one-step ligand exchange technique to introduce the organic surface functionality of interest chosen to target either specific or broader classes of heavy metals. Functionalized superparamagnetic nanoparticles are excellent sorbent materials for the extraction of heavy metal contaminants from environmental and clinical samples since they are easily removed from the media once bound to the contaminant by simply applying a magnetic field. These engineered magnetic nanoparticle sorbents have an inherently high active ...
Since the first operation of nuclear steam generator early 1960s, its performance requirements have been met but the steam generator problems have been met but the steam generator problems have been major cause of reducing the operational reliability, plant safety and availability. U-tube assembly of steam generator forms the primary system pressure boundary of the plant and have experienced several types of tube degradation problems. Tube failure and leakage resulting from the degradation will cause radioactive contamination of secondary system by the primary coolant, and this may lead to unplanned plant outages and costly repair operations such as tube plugging or steam generator replacement. For the case of steam generators for heavy water reactors, e.g. Wolsong 2, 3, and 4 NPP, a high cost of heavy water will be imposed additionally. During the plant operation, steam generator tubes can potentially be subject to adverse environmental ...
A.C.R.O. (Association pour le Controle de la Radioactivite dans l Ouest) is a French non governmental organisation that operates a laboratory for radioactivity analysis. It was created in 1986 as a response to people demands for information and reliable, independent testing. The organisation mainly carries out missions of information and training for its correspondents and more generally for a wide audience, particularly for people who worry about problems of environment, health, management of radioactive waste and emissions. Thanks to its structure, it enables citizens to involve themselves together with scientists so as to gain access to information that was hither to reserved to specialists. The organisation can vouchsafe its independence from the diversity of its members and volunteers, as well as from the diversity of its money resources. Besides its headquarters situated on the city of Caen area (Normandy), three branches situated in North Normandy, in Touraine and North Cotentin ...
The detection, in European steam generators, of intergranular stress corrosion cracking initiating from the primary side (PWSCC) and the somewhat similar detection of intergranular stress corrosion (IGSCC) and intergranular corrosion (IGA) initiated from the secondary side in Japanese steam generators has led to a growing awareness of the potential for such corrosion forms in United States PWR steam generators. What had been a minor occurrence at several units is now a cause of concern and repair measures at more than 30 sites in the United States, and in some cases, is the major cause of steam generator unavailability. The United States nuclear utilities and EPRI formed the first Steam Generator Owners' Group (SGOG) in 1977 in response to the prospect of continued denting corrosion. The occasional appearance of PWSCC, IGSCC and IGA in domestic steam generators was not a sufficient cause for initiating an extensive research program in SGOG I. In SGOG II (1983-1986), an understanding of ...
There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and carbonaceous deposits, ...
BackgroundThe epidemiology of avian influenza viruses (AIVs) in gulls is only partially known. The role of the world's most numerous gull species, the black-legged kittiwake (Rissa...Full Text Available
Highly polymorphic genes with central roles in lymphocyte mediated immune surveillance are grouped together in the major histocompatibility complex (MHC) in higher vertebrates. Generally, across vertebrate...Full Text Available
Demographic and health surveillance (DS) systems monitor and document individual and group-level processes in well-defined populations over long periods of time. The resulting data are complex...Full Text Available
The surveillance systems have been widely used in automatic teller machines (ATMs), banks, convenient stores, etc. For example, when a customer uses the ATM, the surveillance systems will record his/her face information. The information will help us understand and trace who withdrew money. However, when criminals use the ATM to withdraw illegal money, they usually block their faces with something (in Taiwan, criminals usually use safety helmets or masks to block their faces). That will degrade the purpose of the surveillance system. In previous work, we already proposed a technology for safety helmet detection. In this paper, we propose a mask detection technology based upon automatic face recognition methods. We use the Gabor filters to generate facial features and utilize geometric analysis algorithms for mask detection. The technology can give an early warning to save-guards when any "customer" or "intruder" blocks ...
OBJECTIVE--To review and analyse the changing incidence of gonorrhoea and the increasing antibiotic resistance in gonococci in Australia from 1981 to 1991. DESIGN--Use of data from the sample of gonorrhoea...Full Text Available
BackgroundMarburg virus (MARV), a zoonotic pathogen causing severe hemorrhagic fever in man, has emerged in Angola resulting in the largest outbreak of Marburg hemorrhagic fever...Full Text Available
BackgroundCharacterizing infectious disease burden in Africa is important for prioritizing and targeting limited resources for curative and preventive services and monitoring the...Full Text Available
The p53 tumour suppressor plays a pivotal role in the prevention of oncogenic transformation. Cancers frequently evade the potent antitumour surveillance mechanisms of p53 through mutation of the TP53...Full Text Available
BackgroundThe natural history of bronchial preinvasive lesions and the risk of developing lung cancer in patients with these lesions are not clear. Previous studies have treated...Full Text Available
BackgroundMost maternal deaths in developing countries can be prevented. China is among the 13 countries with the most maternal deaths; however, there has been a marked decrease...Full Text Available
... Buckeye rapidly produces high resolution imagery over a commander's area of interest contributing to intelligence, surveillance and reconnaissance, and also creates detailed mapping of the battlespace. BIG uses an innovative, original and creative combination of Web programming languages, Geographic Information Systems, and ...
...because it had greatly contributed to the geospatial capability of coalition forces in the Global War on Terrorism by producing a system that provides high-resolution imagery for use in detecting ground changes, creating detailed maps and obtaining Intelligence, Surveillance and Reconnaissance (ISR) information. ...
Microglia provide immune surveillance for the brain through both the removal of cellular debris and protection against infection by microorganisms and “foreign” molecules. Upon...Full Text Available
1 to the operator of a waste collective system by an agreement or contract. The conditions for the ...Fees of the waste collective system are subject to the supervision of the authority responsible for market surveillance. ...The operator of waste collection system collects wastes from producers and holder and transports these to a collection
ObjectiveThe aim of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography focusing tracheostomy tube and innominate artery for...Full Text Available
Empirical treatment is best guided by current surveillance of local resistance patterns. The goal of this study is to characterize the prevalence of antimicrobial nonsusceptibility within pneumococcal...Full Text Available
Childhood cancer survivors often experience complications related to cancer and its treatment that may adversely affect quality of life and increase the risk of premature death. The purpose of this...Full Text Available
A cross sectional population based epidemiological survey of 899 adults aged between 15 and 59 was undertaken in two urban areas of demographic surveillance sites in Dar es Salaam, Tanzania, using the...Full Text Available
A duplex TaqMan real-time RT-PCR assay was developed for the detection of California (CAL) serogroup viruses and Cache Valley virus (CVV), for use in human surveillance. The targets selected...Full Text Available
Recently, in various production engineering of inorganic chemistry system, a large quantity of acids such as nitric acid and hydrocholoric acid have been used, the examples that acid and slats with high concentration are included in the sewer, treatment technique of acid-effluent in the sewer has been known as the diffusion-dialysis, acid-retardation using anion exchange resin. In this report, treatment and properties of acid-effluent recovery and effect of a coexisting slat by the diffusion-dialysis and acid retardation were compared. In the acid retardation, the concentration beyond the solution system can be recovered when the flow interval between waste acid and water was selected appropriately. In the diffusion-dialysis, it has a tendency that rate of recovery was low in the week acid. However, even in the case of which metal irons form complex anion, it is possible that acid and slat were separated well. 7 refs., 11 figs., 2 tabs.
Iron concentration control in feedwater is one of the most important subjects in waterchemistry. Especially for the BWR plants without 100% flow volume of hollow fiber filter (HFF), rather high iron concentration in feedwater is one of the big issues as this causes relatively high radiation dose rate in drywell area. Cation exchange resins especially used in the plants with partial flow rate of HFF are expected to have the important role of capturing iron in feedwater. For this purpose, we have investigated the effective method for using iron absorption characteristics of cation exchange resin. The Cation-Over Layer method (COL) in condensate demineralizers (CD) effectively utilizes these characteristics. In order to demonstrate a performance of the cation overlay method, we had applied this method for three CD vessels at Fukushima Daiichi NPP Unit 3 for testing purpose. The result of this actual plant test indicated that the iron ...
This is the final report of the Finnish Research Programme on Climate Change (SILMU). This report includes the final results and conclusions made by the individual research groups. The aim of this report is to lay out the research work, and to present the main results and conclusions obtained during the six-year work. The Finnish Research Programme on Climate Change (SILMU) was a multidisciplinary national research programme on climate and global change. The principal goals of SILMU were: (1) to increase our knowledge on climate change, its causes, mechanisms and consequences, (2) to strengthen the research on climate change in Finland, (3) to increase the participation of Finnish researchers in international research programmes, and (4) to prepare and disseminate information for policy makers on adaptation and mitigation. The key areas of the research were: (1) quantification of the greenhouse effect and the magnitude of anticipated climatic changes,(2) assessment of the effects of ...
Vertical U-tube steam generators in Pressurized Water Reactors (PWRs) operating an All Volatile Treatment (AVT) secondary chemistry have experienced corrosion problems, particularly denting and sludges. The studies reported evaluate the feasibility of using a low-concentration (0.5 wt%) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The process potentially may be applied at schedule intervals, such as during normal refueling outages, to maintain a steam generator in clean operating condition. This report describes the results of testing to evaluate the effectiveness of several chelant acids for dissolving steam generator sludges and crevice magnetite. Corrosion of carbon steel by the chelant acids and the effects of various inhibitors are evaluated. The effectiveness of ion-exchange regeneration of several chelant-based ...
Steam generators (SG) are the weak link of nuclear power plants, their service life is shorter than the service life of other NPP components. This paper is dedicated to a statistical analysis of SG damages and failures. Heat exchanging tubes (HET) are the most damaged elements in SG, there are on average 286 plugged or repaired tubes in each operating SG. The usually mechanisms of tube failure are the following: denting, corrosion at tube outside, pitting, fretting, and circular crack propagation. Most of damages are located in the transition zone above a tube plate. This study shows that the factors that are involved in the SG HET fault probability are: - design features of SG and secondary equipment elements (high pressure feed heaters (HPFH), low pressure feed heater (LPFH)), - waterchemistry at different points of condensate feed pipe, composition and density of deposits on HET surface, efficiency of mechanical and chemical washing, - the ...
Four very common long term mineralogical changes in salt formations are discussed in the view of the safety considerations for underground repositories. Two of these processes, the 'Hartsalz' and 'Carnallite' dissolution were studied in two scale in situ experiments. The results are presented and compared with the results of the geochemical modelling with the computer code EQ3/6. Furthermore the reactions leading to the formation of the gypsum cap rock on the top of the Zechstein salt formations and to the polyhalitization of anhydrite are discussed. Geological field observations and mineral assemblages agree well with the results of the geochemical modelling employing the Pitzer formalism along with the Harvie, Moller and Weare database. We conclude that once the mechanisms of the chemical reactions are well understood it becomes possible to evaluate realistically whether such processes, when encountered in the repository, are still active or whether they are finished. It also becomes ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning ...
This project evaluated the feasibility of using a low-concentration (approx. 0.5 wt %) chemical cleaning process to remove corrosion product deposits from steam generator surfaces and magnetite from tube-to-support plate crevices of PWR steam generators. The primary objective was to develop a dilute process that could be safely applied at scheduled intervals, such as during normal refueling outages, to maintain a clean operating condition in the steam generator. The dilute chemical cleaning process developed in this project was demonstrated successfully on two model generators which were operated on faulted chemistry by DOE/CRC at Commonwealth's State Line Facility. Unit 5 was cleaned after 48 days of operation with 1% seawater fouling, and Unit 6 was cleaned after 112 days of operations with Lake Michigan water. This report describes work leading to the model generator cleaning demonstrations and provides details of the cleaning operation for ...
In the course of observing by means of Auger spectroscopy graphite gasification reactions catalyzed by metals, it has been found that in the presence of hydrogen, nickel appears to diffuse from the surface into the bulk of the graphite. When potassium is deposited on graphite, it is volatilized above 400/sup 0/C. Surprisingly the production of methane and carbon dioxide from the reaction of graphite and steam was catalyzed by potassium at as low a temperature as 250/sup 0/C. It has been shown that literature on the alkylation of benzene with synthesis gas is erroneous and that the products reported are due to Lewis acid catalyzed cracking of benzene. A novel cobalt mediated, reversible cleavage of a vinyl-hydrogen bond has been discovered. All products from the thermal decomposition of tetralin have been identified. The stereochemistry of cis-1, 2 dihydrotetralin was determined. In the utilization of the water gas shift reaction as a reducing agent for model coal ...
This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) including calendar year 2008 results. Each of the three Pilot Wells was sampled on March 11, 2008, and September 10, 2008. These wells were sampled for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. Indicators of general waterchemistry (cations and anions) were also monitored. Results from all samples collected in 2008 were within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. These data indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS. There were no significant changes in measured groundwater parameters compared to previous years. Other information in the report includes an updated Cumulative Chronology for the Area 5 RWMS Groundwater ...
This report is a compilation of the groundwater sampling results from the Area 5 Radioactive Waste Management Site (RWMS) for calendar year 2006. Pilot wells UE5PW-1, UE5PW-2, and UE5PW-3 were sampled in April and October 2006 for the following indicators of contamination: pH, specific conductance, total organic carbon, total organic halides, and tritium. Indicators of general waterchemistry (cations and anions) were also monitored. Results from all samples collected in 2006 were within the limits established by agreement with the Nevada Division of Environmental Protection for each analyte. These data indicate that there has been no measurable impact to the uppermost aquifer from the Area 5 RWMS. There were no significant changes in measured groundwater parameters compared to previous years. Other information in the report includes an updated Cumulative Chronology for the Area 5 RWMS Groundwater Monitoring Program and a brief description of ...
The objective of this research was to determine improved thermal, epithermal, and fast fluxes and several responses at mechanical test surveillance location keys 2, 4, 5, and 7 of the pressure vessel of the Oak Ridge National Laboratory High Flux Isotope Reactor (HFIR) for the beginning of the fuel cycle. The purpose of the research was to provide essential flux data in support of radiation embrittlement studies of the pressure vessel shell and beam tubes at some of the important locations.
Monitoring and diagnostic systems are of main importance for a safe and efficient operation of nuclear power plants. The author describes new developments with respect to vibration monitoring with a functional extension in the time domain for den secondary circuit, the development of a local system for the surveillance of rotating machines, the structure-borne sound monitoring with improvement of event analysis, esp. the loose part locating, leakage monitoring with a complete system for humidity measurement, and the development of a common platform for all monitoring and diagnostic systems, that allows an efficient access for comparison and cross references.
The recent definition of a postulated thermal shock accident followed promptly by system repressurization, termed an overcooling or pressurized thermal shock accident, has set a large analysis and research effort into motion. The essential elements are concerned with defining the accident transients, evaluating the instrumentation and controls that cause the postulated accidents, and evaluating the metallurgical and structural mechanics aspects of the reactor vessel with respect to its failure potential. This paper poses the question faced by the Nuclear Regulatory Commission (NRC) for the vessel steel embrittlement, annealing, and surveillance dosimetry facets of this postulated accident and provides information on our plans for study of this problem as well as current status.
The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied waterchemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In addition to bulk ...
CF-23“The biggest stumbling block for biological sciences turned out to be synthetic organic chemistry” – Elias A. Zerhouni, Former NIH Director in Chemical...Full Text Available
The consequences of structural modifications at the 5'-OH ribofuranotide moiety of quinoline modified B12 derivatives are discussed in regard of the coordination chemistry, the electrochemical properties and the biological behaviour of the compound. PMID:21850334
Hydrothermal oxidation (HTO) is a promising technology for the treatment of aqueous-fluid hazardous and mixed waste streams. Waste streams identified as likely candidates for treatment by this technology are primarily aqueous fluids containing hazardous organic compounds, and often containing inorganic compounds including radioisotopes (mixed wastes). These wastes are difficult and expensive to treat by conventional technologies (e.g. incineration) due to their high water content; in addition, incineration can lead to concerns related to stack releases. An especially attractive potential advantage of HTO over conventional treatment methods is the total containment of all reaction products within the overall system. The potential application of hydrothermal oxidation (HTO) technology for the treatment of DOE hazardous or mixed wastes has been uncertain due to concerns about safe and efficient operation of the technology. In principle, aqueous DOE wastes, including ...
The discovery of nearly sixty molecules, often unstable or complexes, in the interstellar space has been one of the greatest surprises of contemporary astronomy. We may, indeed, be surprised that molecules having up to 13 atoms might be synthetized in an extremely diluted space and at a very low temperature. That these molecules are, most of all, organic molecules is another astonishing subject, at least for the non-specialist. The interstellar molecule formation is indeed well understood nowadays, at least for the simplest ones. This article takes stock of interstellar chemistry which is essentially an ionic chemistry very different from laboratory chemistry.
CoTreat, a new inorganic ion exchange media, has been studied in the laboratory to support its application as a pre- coat to existing Funda filters in THORP feed pond plant (Sellafield, UK). This is a novel way of application of CoTreat, which is usually utilized in fixed-bed ion exchange columns in a granular form. The results present the effect of operating conditions (CoTreat dose, pond waterchemistry) on CoTreat performance for the removal of Co-57 tracer from simulated pond water. Major findings include the strong dependence of Co-57 decontamination factor (DF) on feed activity. At the 200 Bq/L feed level, the observed DF was 10-20 but rose to 1000 and above when the feed level was increased to 20000 Bq/L. Calcium present in the feed was found to decrease the DF at concentrations higher than 1 ppm. The laboratory studies showed significantly higher DF's than what has been observed in large-scale THORP tests. ...
The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer ...
In Japan, the development of next-generation Light Water Reactor has been launched since April 2008. The development program will be completed in 2015. The purpose of development is to cope with the replacement for existing nuclear power plants after 2030 in Japan and the expanding demand for nuclear power in the world; 'Nuclear Renaissance.' The reactor also aims to be global standard at around 2030. The requirements for global standard and domestic users have been investigated through the feasibility study of past 2 years, 2006-2007, and six innovative features or 'Core-Concepts' were established as follows. A) Reactor core system with uranium enrichment above 5% for significant decrease of spent fuel discharge and prominent higher availability B) Long-life materials and innovative waterchemistry technologies for 80 years plant lifetime and significant reduction of occupational dose C) Seismic isolation technologies to ...
In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water ...
The synthesis and structures of acyclic and macrocyclic thio-, seleno- and telluro-ether complexes of the metallic and metalloid elements of Groups 13-16 reported since 2000 are described. The diverse structures range from discrete monomers through to infinite 1-, 2- or 3-D polymers. The coordination chemistry in this area is quite different to familiar d-block chemistry and the underlying factors are explored. PMID:21706103
The application of photopolymerisation (UV) and electron beams (EB) technologies in radiation rapid cure (PRC) processing is discussed. The chemistry associated with such reactions and the mechanisms of the processes are treated. The occurrence of concurrent grafting to substrate with radiation curing of films is shown to be an advantage in enhancing the properties of certain finished products. The parameters influencing the optimum grafting yield in such PRC processes are discussed. In many applications, the chemistry of such processes combined with the machine, specially for EB is shown. (author).
Executive summaryForewordPublic awareness of solid-state chemistry, or more broadly solid-state science and technology rapidly grew along with the transistor revolution and the development of the integrated circuit. We are now at the half-way point in the solid state century [Scientific American The Solid-State Century 1997;8(1) [special issue
As regards the environmental protection, the A.C.R.O. maintained in 2001 its programs of surveillance around the main western nuclear installations of France. The radioecological surveillance of the site of Cogema La-Hague for the dismantling of the former pipe of release in sea was one of the key points of this action environmental surveillance. The two accidents of atmospheric release in may and october 2001 at Cogema La Hague have shown the interest of an association as A.C.R.O.. It is thank to the measure, by our laboratory, of repercussions on environment of these incidents that it has been possible to bring to light a dysfunction of the measurement system of the gaseous effluents released by the facility operator. To improve the public information, A.C.R.O. concerns its main efforts on the development of the consumer technical information available on-line via its web site and in its regular publication 'the ...
Addition of Gadolinium Nitrate as chemical shim to moderator heavy water of 540 MWe PHWR, at 15 mg/kg level (at a pH of 5.0) is practiced for reactor shutdown purposes. Presently a strong acid cation exchanger column is used for this purpose. During this operation, the moderator pH of 3.8, with the IX column outlet pH of ?3.5-3.6 was observed against the technical specification demand that when Gd is present, the pH of moderator must be in the range of 5.0-5.5. In order to achieve an iso-pH regime during Gd removal, studies were conducted using a mixed bed of strong acid cation resin plus a weak base anion resin (loaded in the volume ratio of 1 : 6), backed up in the same column (bottom most layer) by a 5 % nitric acid loaded weak base resin and topped by a strong acid cation resin (uppermost layer) simulating system flow velocity and percentage loading of resin. Using such a column it is demonstrated that Gd removal could be achieved simultaneously maintaining the ...
Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH{sub 4}). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH{sub 4} release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr{sup -1} of which 34 percent (38 Tg yr{sup -1}) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N{sub 2}O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N{sub 2}O also is an effective greenhouse gas. Land-use activities and environmental changes can affect ...
Richmond Harbor is on the eastern shoreline of central San Francisco Bay and its access channels and several of the shipping berths are no longer wide or deep enough to accommodate modem deeper-draft vessels. The Water Resources Development Act of 1986 (PL99-662) authorized the US Army Corps of Engineers (USACE), San Francisco District to deepen and widen the navigation channels in Richmond Harbor. Several options for disposal of the material from this dredging project are under consideration by USACE: disposal within San Francisco Bay, at open-ocean disposal sites, or at uplands disposal sites. Purpose of this study was to conduct comprehensive evaluations, including chemical, biological, and bioaccumulation testing of sediments in selected areas of Richmond Harbor. This information was required by the Environmental Protection Agency (EPA) and USACE. Battelle/Marine Sciences Laboratory collected 20 core samples, both 4-in. and 12-in., to a project depth of -40 ft ...
The most relevant aspects of research and service experience with environmentally-assisted cracking (EAC) of carbon (C) and low-alloy steels (LAS) in high-temperature (HT) water are reviewed, with special emphasis on the primary pressure boundary components of boiling water reactors (BWRs). The main factors controlling the susceptibility to EAC under light water reactor (LWR) conditions are discussed with respect to crack initiation and crack growth. The adequacy and conservatism of the current BWRVIP-60 stress corrosion cracking (SCC) disposition lines (DLs), ASME III fatigue design curves, and ASME XI reference fatigue crack growth curves, as well as of the GE EAC crack growth model are evaluated in the context of recent research results. The operating experience is summarized and compared to the experimental/mechanistic background knowledge. Finally, open questions and possible topics for further research are identified. ...
A new surveillance system for Oil-Filled cable, which can provide continuous monitoring, using a newly developed optical gas sensor that can detect the concentration of the gas dissolved in the oil with extremely high sensitivity has been developed. It was proved that the degree of deterioration of the insulating oil can be detected by measuring C{sub 2}H{sub 2} and CH{sub 4} by investigating the relation between the degree of deterioration and amount of combustible gas generated. In order to detect extremely small amounts of gas, a new gas detecting method using absorption line of the gas using a frequency modulated technique has been developed. The gas detection ability was also confirmed by examination using a 66 kV of cable and the possibility of detection at an early stage is expected.
We propose a novel surveillance system that uses hybrid camera network. The system contains a panorama camera and PTZ cameras to take the wide range images and face images at high enough resolution for identification tasks. The robust human detection methods include robust background subtraction method (RRC), skin color segmentation and face tracking method. First, the system detects persons from a panorama image, and then the detailed face images are obtained with the PTZ cameras. The PTZ cameras can track the faces using the four directional features and the relaxation matching. In addition, the system has automatic camera position calibration feature. Thus, the user can use the system without any troublesome settings.
The foundation conducts an environmental monitoring and surveillance program over an area covering much of the upper Snake River Plain and provide environmental education and support services related to INEL natural resource issues. Also, the foundation, with its university affiliates, conducts ecological and radioecological research on the Idaho National Environmental Research Park. This research benefits major DOE-ID programs including waste management, environmental restoration, spent nuclear fuels, and land management issues. Major accomplishments during CY1995 can be divided into five categories: environmental surveillance program, environmental education, environmental services and support, ecological risk assessment, and research benefitting the DOE-ID mission.
Sulfate attack of cement-based materials remains an important problem for the durability assessment of containers and disposal engineering barriers dedicated to the long-term storage of radioactive wastes since underground water which may reach these elements contains small quantities of sulfates (7-31 mmol/1). This work contributes to the study of sulfate-induced damage mechanisms, to their understanding and modelling. The experimental phases of this study aimed at the understanding of the different physico-chemical phenomena involved during an external sulfate attack at following their evolution and their impact on the transport and mechanical properties of the material. Leaching experiments in pure water and in a solution of sodium sulfate (with a sulfate content of 15 mmol/1), have been performed simultaneously on OPC paste (w/c 0,4)in order to allow a comparison of test results. The frequent analysis of the leachant has shown a consumption ...
Clean Water Act You are here: Water Laws & Regulations Policy & Guidance Clean Water Act Water Quality and 401 Certification Water Quality and 401 Certification Water Quality...
Several works about annual meeting of the Brazilian Chemical Society are present.The search for medicinal chemistry, natural products, biological chemistry, and organic chemistry are shown. Conventional methods and some techniques are discussed and developments of new methods of determining are studied. The use of new chemical compounds, materials, structures and chemical analysis are shown.
This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)
The diffusion coefficients (De) in bentonite were measured to understand and quantify the influence of groundwater chemistry such as ionic strength and to quantify the alteration of smectite mineralogical transformations. (author)
... Astronomy & Space Biology Chemistry & Materials Computing Earth & Environment Education ... Materials Research Center at the University of Chicago, one of nearly 30 NSF-supported Materials ...
... the effect of MBH on steam generator crevice corrosion; model boiler test results show that MBH is effective against denting corrosion and Alloy 600 ...
The purpose of this statement of work (SOW) is to establish laboratory analytical criteria and requirements for radioactive airborne emissions measurement sample and/or analysis activities.
The Liver Carcinogenesis Section uses the modern technologies of molecular biology, cell biology, protein chemistry and genetics to investigate the biochemical and genetic pathways involved in human liver cancer.
Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are important to define.
The nitric oxide molecule is being studied in order to understand the energetics and chemistry of initiation and detonation in liquid NO at the molecular level. An overview is presented of the work being done. (DLC)
Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and...Full Text Available
The NASA Langley Distributed Active Archive Center archives and distributes data relating to Radiation Budget, Clouds, Aerosols, and Troposheric Chemistry.
... with dynamic gridding capability to account for material ablation, as well as the addition of energy sources and heat transfer augmentation due to ...
Among 235 extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL) isolates collected from a nationwide surveillance performed in Taiwan, 102 (43.4%) were...Full Text Available
Set up in 2004 by the A.C.R.O. the citizens network of radioecological surveillance, information and evaluation (R.I.V.I.E.R.E.) aims at making a follow-up of the radioactive contamination of the aquatic ecosystems on the scale of the Seine-Normandy pond: from Nogent-on-Seine to La Hague and from the Mont-Saint-Michel to the Treport. The peculiarity of this network, which also makes its strength is to associate strictly all those who wish to appropriate the knowledge of the radioactivity levels around to them. With R.I.V.I.E.R.E., the citizen is at the same moment an author and an actor of the surveillance of his environment as his information. An approach defended by the A.C.R.O. since about 20 years and which has no equivalent anywhere else. This project has four main objectives: to know the levels and the tendencies of the present radioactivity in the main aquatic ecosystems of the Seine-Normandy widened pond, and so feed a data base ...
Pneumococcal disease in young children has not been as well characterized in East Africa as it has been in industrialized countries. Although pneumococci are likely to cause substantial mortality...Full Text Available
The paper deals with the disposal of radioactive waste and the plans for dealing with solid wastes of intermediate and low levels of activity, which are the responsibility of NIREX. NIREX is an executive body which co-ordinates the waste-disposal plans of the main radioactive waste producers. The disposal routes for the active wastes are described including the deep disposal of wastes containing material that will remain active for thousands of years. Requirements for deep burial are outlined with reference to the geology and hydrogeology of the site. Monitoring, maintenance and surveillance are mentioned for the protection of the public.
This book contains the proceedings of the International Topical Meeting on Remote Systems and Robotics in Hostile Environments. It is organized under the following sessions: Worldwide Applications Overview; Operating Mobile Systems; Sensors and Control Systems; Space Applications; Reactor Operations and Surveillance; Remote Equipment for Hazardous Operations; Future Mobile System; Mining and Construction Operations; Special Applications; Hot Cell Applications; Processing; Reactor Operations and Maintenance; Decontamination and Waste Handling; Remote Handling Development and Demonstration.
It is maintained that special features of FFTF make it an ideal system to test sodium boiling detection techniques by acoustic/neutronic methods and to test the response of acoustic/neutronic sensors to vibrations. It is shown that accumulated research results indicate that such tests in FFTF are feasible, predictable, promising and safe. (author).
A nationwide antimicrobial resistance surveillance has been conducted since 1997 in Korea. In this study, susceptibility test data generated in 2004 by KONSAR group hospitals were analyzed and compared...Full Text Available
A nationwide surveillance for antimicrobial susceptibility in Escherichia coli strains isolated from food-producing animals in Japan was conducted from 1999 to 2002. Eighteen cefazolin-resistant...Full Text Available
The CNS is a unique organ due to its limited capacity for immune surveillance. As macrophages of the CNS, microglia represent a population originally known for the ability to assist neuronal stability,...Full Text Available
Software quality assurance (SQA) for robotic systems used in nuclear waste applications is vital to ensure that the systems operate safely and reliably and pose a minimum risk to humans and the environment. This paper describes the SQA approach for the control and data acquisition system for a robotic system being developed for remote surveillance and inspection of underground storage tanks (UST) at the Hanford Site.
A case is presented in which the diagnosis of acute myelomonocytic leukemia was made 16 months after the start of irradation and chemotherapy for Ewing's sarcoma. The association of these two diseases is rare. The etiologic role of therapy in the development of leukemia is speculative in this case. However, there is need for surveillance for secondary neoplasms of all types so that the benefits of therapy may be properly weighed against the risks.
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Based upon the existing regulatory cleanup criteria, remediation of this wetlands was proposed by the New Jersey Department of Environmental Protection and Energy (NJDEPE). This remedial process would have totally destroyed a thriving Old Field Wetlands. Site-Specific evaluation of the chemicals of potential concern (CPC), remaining source areas, potential environmental fate and transport (EF and T), toxicology (including oral absorption and bioaccumulation) and potential land use scenarios were conducted. It was determined that although the analytical chemistry data reported soil concentrations of arsenic, the compound used by the facility and discharged to the wetlands sediments was in fact gallium arsenide. Secondly, all remaining source areas and hot spots had previously been remediated. Vertical migration to soils had not progressed past a depth of 3 feet and groundwater/surface water did not contain significantly elevated concentrations ...
This 7th edition reveals the progress in steam engineering and the great future potential of steam engineering applications. Pollution abatement and design experiences gained during the operation of existing plants, and experiences gained in waste incineration are of environmental relevance. Recent materials developments and knowledge, e.g. as regards pipes and fittings, have been making significant contributions to supercritical-steam efficiency improvements. Emphasis is also placed on automation, control engineering, waterchemistry etc., and on regulations, licensing procedures, and the training of the staff of plants. (orig./KOW) [Deutsch] Die nunmehr vorliegende 7. Ausgabe zeigt den Fortschritt und das zukuenftig noch erhebliche Potential dieser Technik auf. Erfahrungen mit den nun schon seit Jahren laufenden Anlagen zur Schadstoffminderung, Konstruktion und Auslegung sowie Betriebserfahrungen zur thermischen Abfallverwertung sind ...
Neurodegeneration observed in Alzheimer disease (AD) is believed to be related to the toxicity from reactive oxygen species (ROS) produced in the brain by the amyloid-{beta} (A{beta}) protein bound primarily to copper ions. The evidence for an oxidative stress role of A{beta}-Cu redox chemistry is still incomplete. Details of the copper binding site in A{beta} may be critical to the etiology of AD. Here we present the structure determined by combining x-ray absorption spectroscopy (XAS) and density functional theory analysis of A{beta} peptides complexed with Cu{sup 2+} in solution under a range of buffer conditions. Phosphate-buffered saline buffer salt (NaCl) concentration does not affect the high-affinity copper binding mode but alters the second coordination sphere. The XAS spectra for truncated and full-length A{beta}-Cu{sup 2+} peptides are similar. The novel distorted six-coordinated (3N3O) geometry around copper in the A{beta}-Cu{sup 2+} complexes include ...
Elements of the environmental effects monitoring program in the Terra Nova oil field, about 350 km east-southeast of St. John's, Newfoundland, are described. This oilfield is being developed using a floating production storage and offloading (FPSO) facility. A total of 24 wells are expected to be drilled through seven subsea templates located in four glory holes to protect them from icebergs. Subsea installations will be linked to the FPSO by trenched flowlines connected to flexible risers. The FPSO will offload to shuttle tankers. First oil is expected in 2001. The environmental effects monitoring program will be conducted annually for the first two years beginning in 2000. Subsequent scheduling will be determined after a review of monitoring data collected during the first three years. Input to the design of the monitoring program was provided by all stakeholders, i. e. owners, local public, government agencies and regional and international experts. A model was developed ...
The liquid-phase synthesis of metal oxide nanoparticles in organic solvents under exclusion of water is nowadays a well-established alternative to aqueous sol-gel chemistry. In this article, we highlight some of the advantages of these routes based on selected examples. The first part reviews some recent developments in the synthesis of ternary metal oxide nanoparticles by surfactant-free nonaqueous sol-gel routes, followed by the discussion of the morphology-controlled synthesis of lanthanum hydroxide nanoparticles, and the presentation of structural peculiarities of manganese oxide nanoparticles with an ordered Mn vacancy superstructure. These examples show that nonaqueous systems, on the one hand, allow the preparation of compositionally complex oxides, and, on the other hand, make use of the organic components (initially present or formed in situ) in the reaction mixture to tailor the morphology. Furthermore, obviously even the crystal ...
Interactions beween a high latitude, continental shelf, spring phytoplankton bloom and water column physics and chemistry were studied using /sup 15/N measured rates of nitrogen uptake. Peak bloom conditions commenced when the mixed layer shallowed and minimized respirational losses. Integrative light-mixing growth models were accurate during early bloom stages. An advection-diffusion model associated peak bloom nitrate uptake with pycnocline mixing rates of 2.1 m d/sup -1/ in an 18 m mixed layer. Maximum nitrogen specific uptake rates (hr/sup -1/), unlike those of carbon, coincided with peak bloom conditions. Although species compositions among peak bloom periods were similar, particulate C/N ratios were not. Apparently, both intercellular factors and prevailing mixing conditions influence specific uptake rates and cell composition. A large proportion of new (nitrate) to total productivity was associated with the dominance of the early bloom ...
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation waterchemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (< 24 x 10{sup 8} m{sup 3}/km{sup 2}) was less than that of the Yulin area (> 32 x 10{sup 8} m{sup 3}/km{sup 2}), the gas supply intensity of the ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with [{sup 99m}Tc(pap){sub 3}]{sup +} ...
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with ["9"9"mTc(pap)_3]"+ showing elevated ...
Acidic constituents in crude oil are associated with the formation of stable emulsions during production and present a challenge for efficient oil recovery and processing. Acid molecules, including naphthenic acids and acidic sulfur in crude oil cause corrosion in refineries and pipelines. Naphthenic acids are also significant because of their surface activity and marginal water solubility, so that they may leach to wastewaters and cause adverse environmental effects. Acidic components of oil are not limited to carboxylic acids but also molecules that contain sulfur and nitrogen. As such, an improved understanding of the chemistry and physics of petroleum at the molecular level is needed in order to understand the range of problems associated with acidic oil components and to design better solutions. The applications of negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for ...
The leached glass is subject to leachant attack and results in surface layer alteration which greatly affects the corrosion progress of glass forms. This work studied the composition change, precipitation, pitting corrosion as well as surface layer break and spallation of the leached glass forms. 6 conclusions can be made: 1. The extent of surface layer alteration is related to many factors such as temperature, pH, leachant chemistry, flow rate and leach duration, etc. 2. The alkali element Na is seriously depleted and the elements like U.Ti,Fe, Ca and Mg are enriched in the surface layer. The influence of media has such order: Fe{sub 2}O{sub 3} > Na-bentonite > Zeolite. 3. The precipitate formed in leach test for 56 days at 90 {infinity}C is mostly amorphous, but after 91 days has crystallized. There is K - Ca - Al - Si crystal,the amount of Al, K and Si is increasing, but the amount of Ca is decreasing along with leaching time. CaCO{sub 3} crystal ...
Surface modification of topography and chemistry in order to achieve a specific water contact angle (CA) has been explored by using a novel combinatorial screening platform. The screening arrays consisted of 507 distinct combinations of micro-topographies and chemical compositions. By performing chemical modifications with 1H, 1H, 2H, 2H perfluoroethyltriethoxy-silane (PFS) and n-octadecyltriethoxysilane (ODS) on standard silicon wafers it was possible to include both superhydrophobic and very hydrophilic pad arrays in the same screening platform. Surfaces modified with PFS were more hydrophobic than surfaces modified with ODS, while the unmodified silicon surfaces were hydrophilic. For the PFS modified surfaces the largest CAs were achieved with a small pillar size of X = 1 {mu}m and an intermediate inter-pillar gap size of Y = 4 {mu}m with superhydrophobic CAs over 170 . Surface analysis with X-ray photoelectron spectroscopy (XPS) revealed ...
The objectives of this project are to support the DOE direct coal liquefaction process development program and to improve the useful application of analytical chemistry to direct coal liquefaction process development. Independent analyses by well-established methods will be obtained of samples produced in direct coal liquefaction processes under evaluation by DOE. Additionally, analytical instruments and techniques which are currently underutilized for the purpose of examining coal-derived samples will be evaluated. The data obtained from this study will be used to help guide current process development and to develop an improved data base on coal and coal liquids properties. A sample bank will be established and maintained for use in this project and will be available for use by other researchers. The reactivity of the non-distillable resids toward hydrocracking at liquefaction conditions (i.e., resid reactivity) will be examined. From the literature and data ...
This report is a compilation of the calendar year 2003 groundwater sampling results from the Area 5 Radioactive Waste Management Site, Nevada Test Site. Wells Ue5PW-1, Ue5PW-2, and Ue5PW-3 were sampled semi-annually for the required analytes: pH, specific conductance, total organic carbon (TOC), total organic halides (TOX), tritium, and major cations/anions. Results from all samples collected in 2003 were within established criteria. These data indicate that there has been no measurable impact to the uppermost aquifer from the Resource Conservation and Recovery Act (RCRA) regulated unit within the Area 5 Radioactive Waste Management Site and confirm that any previous detections of TOC and TOX were false positives. Contamination indicator data are presented in control chart and tabular form with investigation levels indicated. Gross waterchemistry data are presented in graphical and tabular form. There were no major changes noted in the ...
This report summarizes the research conducted during Budget Period One on the project ''Improved Natural Gas Storage Well Remediation''. The project team consisted of Furness-Newburge, Inc., the technology developer; TechSavants, Inc., the technology validator; and Nicor Technologies, Inc., the technology user. The overall objectives for the project were: (1) To develop, fabricate and test prototype laboratory devices using sonication and underwater plasma to remove scale from natural gas storage well piping and perforations; (2) To modify the laboratory devices into units capable of being used downhole; (3) To test the capability of the downhole units to remove scale in an observation well at a natural gas storage field; (4) To modify (if necessary) and field harden the units and then test the units in two pressurized injection/withdrawal gas storage wells; and (5) To prepare the project's final report. This report covers activities ...
Information is given on the theoretical principles underlying the technology of producing fibrous plastics and wood slabs. An examination is made of the most important characteristics of the physics and chemistry of polymers, and the properties of synthetic polymers used in the wood processing industry. A description is given of the chemical composition and properties of wood and its components as well as of synthetic polymers made of cellulose. The book is designed for students of technical schools of the wood and pulp processing industry. 7 references, 14 figures, 1 table.
The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+,...Full Text Available
There are about fifty SET domain protein methyltransferases (PMTs) in the human genome, that transfer a methyl group from S-adenosyl-L-methionine (SAM) to substrate lysines on histone tails or other peptides. A number of structures in complex with cofactor, substrate, or inhibitors revealed the mechanisms of substrate recognition, methylation state specificity, and chemical inhibition. Based on these structures, we review the structural chemistry of SET domain PMTs, and propose general concepts towards the development of selective inhibitors.
...The number of documents that contain the keyword absolute zero is: 2 EU Descartes Prizes for excellence in research and science communication EU Descartes Prizes ...for excellence in research and science communication -Chemistry Close to Absolute Zero - Descartes Prize 2000 - Winner- Ian Smith EU Descartes Prizes for excellence ...in research and science communication EU Descartes Prizes for excellence in research and science communication -Chemistry Close to Absolute Zero - Descartes Prize 2000 ...
The pace of development and fielding of electric vehicles is briefly described and the principal advanced battery chemistries expected to be used in the EV application are identified as Ni/MH in the near term and Li-ion/Li-polymer in the intermediate to long term. The status of recycling process development is reviewed for each of the two chemistries and future research needs are discussed.
This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).
Organic molecules are a significant and highly varied component of atmospheric aerosols. Measurement of aerosol composition and improvements in our understanding of the complex chemistry involved in their formation and aging are being aided by innovations in soft ionization aerosol MS. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.). PMID:21275431
...Correction Discussion Editorial Letter Opinion Review Short Note Technical Note Special Issue all A Systematic Development Method for Rational Drug Design Advances in Molecular Electronic Structure Calculations Algorithms and Molecular Sciences Antimicrobial Agents Application of Density Functional Theory Applications of Density Functional Theory Applications of Molecular Dynamics Atoms in Molecules ...
The paper gives results of experiments in a 0.1 MW pilot plant to determine the effects of high concentrations of chloride ions and dissolved salts on flue gas desulfurization (FGD) scrubbing chemistry, both in the natural and forced oxidation modes of operation. (Note: The tight...
Contents include: introduction; river systems; physical processes; chemical processes; estuaries and coastal zone; introduction; physical processes; chemical processes; the role of sediments; introduction; the anoxic layer; major-element chemistry; minor-element chemistry; the oxic-anoxic interface; assessment; introduction; analysis of sediments; modelling.
... The chemistry of paints and painting by A H. 1834-1915 Church (Paperback - Aug. 24, 2010) Buy new: $35.75 $27.17 17 Used & new from $20.42 Get it by Thursday, Sept. 8 if you order in the next 16 hours and choose one-day shipping. Eligible for FREE Super Saver Shipping. Only 1 ...
The IAEA has requested several member states to present their proposal of the application of the Integrated Safeguards (IS) system in their nuclear facilities. This report contains a IS proposal for Finland prepared under the Task FIN C 1264 of The Finnish Support Programme to IAEA Safeguards. The comprehensive safeguards system of the International Atomic Energy Agency (IAEA) has been one of the main tools in the fight against nuclear proliferation since the entry-into-force of the Nuclear Non-proliferation Treaty three decades ago. In the 1990s some of the inherent weaknesses of this so-called traditional safeguards system were revealed first in Iraq and then in North Korea. Therefore, the member states of the LAEA decided to give the Agency additional legal authority in order to make its control system more effective as well as more efficient than before. This was accomplished by the approval of the so-called Model Additional Protocol (INFCIRC/540) in 1997. Straightforward ...
Immunoassays are versatile analytical techniques that had a leading role in various clinical applications, during the last four decades. The studies carried out by Rosalyn Yalow, Solomon Berson and Roger Ekins in the 1960s gave a breakthrough in the development of this novel analytical method. Sensitivity up to femtomolar concentrations, high specificity and universal application to different classes of molecular species made immunoassay a very useful tool in analytical investigation. The expertise acquired by immunochemists in producing antibodies against any antigen and the ability of radiochemists in labeling the antigens with "1"2"5I without affecting the active site are the two main factors responsible for the above development. There are concerns about the safety and health of humans due to the high-level contamination of environment by pesticides, industrial compounds and metals, anabolic steroids in milk and meat products, and presence of mycotoxins in food and feed ...
A test methodology for measuring temperature, impedance, pH, and electrochemical potential distributions within a sludge-packed tube support plate crevice in a laboratory test is described. The method successfully showed that there were large concentration gradients between the tube and tube support plate sides of the crevice. The testing also showed that strong bases concentrated more effectively than strong acids, and that the crevice pH, when exposed to seawater-based solutions, increased with increasing superheat and decreasing bulk concentration. The large variations in the crevice chemistry observed under heat transfer were eliminated upon shutdown. These new test data suggest that it might be beneficial to evaluate the variation in the extent of stress corrosion cracking with tube support plate elevation found in some steam generators in light of local chemistry changes, as well as the variation in tubing temperature. Because of the ...
Two plasma chemistries, i.e., CH_4/H_2/Ar and Cl_2/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH_4/H_2/Ar discharges appears to be ion driven, Cl_2/Ar discharges showed an additional strong chemical enhancement. The highest etch rate (#approx#1 #mu#m/min) for InGaP was achieved at high ICP source power (#>=#750 W) with the Cl_2/Ar chemistry. Cl_2/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP (#approx#100 Angstrom) with Cl_2/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH_4/H_2/Ar plasma chemistry produced somewhat rougher surfaces ...
Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors and in reactors in Germany. The grade of Alloy 800 tubing used for this service has a controlled Ti/C ratio ({>=}12 for CANDU SGs), and this specification is sometimes termed Alloy 800 M or Alloy 800 NG . There have been very few corrosion-related flaws detected in this material in SG service, and, until recently, no incidences of cracking. There has been extensive R and D carried out on Alloy 800 tubing, both in Canada and elsewhere, under a variety of operating conditions, including shutdowns, which show that it has excellent resistance to corrosion-related degradation under specified and appropriate operating conditions. These R and D findings are reflected in the in-service experience. It has been shown from the R and D that Alloy 800 is susceptible to corrosion under acidic conditions, in particular those that can arise as a consequence of phosphate ...
Alloy 800 has been used for steam generator (SG) tubing for more than 30 years, primarily in CANDU reactors and in reactors in Germany. The grade of Alloy 800 tubing used for this service has a controlled Ti/C ratio (#>=#12 for CANDU SGs), and this specification is sometimes termed Alloy 800 M or Alloy 800 NG . There have been very few corrosion-related flaws detected in this material in SG service, and, until recently, no incidences of cracking. There has been extensive R and D carried out on Alloy 800 tubing, both in Canada and elsewhere, under a variety of operating conditions, including shutdowns, which show that it has excellent resistance to corrosion-related degradation under specified and appropriate operating conditions. These R and D findings are reflected in the in-service experience. It has been shown from the R and D that Alloy 800 is susceptible to corrosion under acidic conditions, in particular those that can arise as a consequence of phosphate ...
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The indirect conversion of coal to liquid hydrocarbons via steam gasification followed by synthesis gas (CO/H/sub 2/) chemistry has been the subject of intensive study for a number of decades. A key technological challenge facing researchers in this area is control over the product distribution during the hydrocarbon synthesis step. In the case of iron Fischer-Tropsch catalysts, it has been known that the addition of alkali to the metal catalyst has a significant impact on the product distribution. Iron catalysts treated with alkali produce less methane more alkenes and higher molecular weight products. In spite of numerous investigations, the details of this promotional effect are not understood on a molecular level. To explore the role of alkali in the surface chemistry of iron catalysts, the authors have carried out a combined surface science and catalytic kinetic study of a model iron catalyst with and without surface alkali.
A reasonable understanding of PWR steam generator corrosion mechanisms such as denting and wastage has been developed, and adequate chemistry control programs defined to obviate the magnitude and effects of these modes of attack. However, relatively unique corrosion attack modes have been encountered at several plants notwithstanding the presence of a reasonable to very good chemistry control program when considered in light of the Steam Generator Owners Group chemistry guidelines. The uniqueness of attack also suggests that parameters not routinely measured or monitored may be playing a significant role. In the authors opinions, the only reasonable method of routinely identifying corrosion accelerating species present in crevices, sludge piles, and deposits in PWR steam generators is by performing detailed chemical return studies during power transients, shutdowns, and long term layups. Although it would be preferable to ...
This study report presents the shutdown chemistry of PWR primary system to reduce and remove the radioactive corrosion products which were deposited on the nuclear fuel rods surface and the outside of core like steam generator channel head, RCS pipings etc. The major research results are the follows ; the deposition radioactive mechanism of corrosion products, the radiochemical composition, the condition of coolant chemistry to promote the dissolution of radioactive cobalt and nickel ferrite, the control method of dissolved hydrogen concentration in the coolant by the mechanical and chemical methods. The another part of study is to investigate the removal characteristics of corrosion product ions and particles by the demineralization system to suggest the method which the system could be operate effectively in shut-down purification period. (author). 19 refs., 25 figs., 48 tabs.
Plant secondary chemistry is determined by both genetic and environmental factors, and while large intraspecific variation in secondary chemistry has been reported frequently, the levels of genetic variation of many secondary metabolites in forest trees in the context of potential resistance against pests have been rarely investigated. We examined the effect of tree genotype and environment/site on the variation in defensive secondary chemistry of lodgepole pine, Pinus contorta var. latifolia, against the fungus, Grosmannia clavigera (formerly known as Ophiostoma clavigerum), associated with the mountain pine beetle, Dendroctonus ponderosae. Terpenoids were analyzed in phloem samples from 887, 20-yr-old trees originating from 45 half-sibling families planted at two sites. Samples were coll...
A comprehensive review was conducted of primary helium coolant chemistry data, based on current and past operating histories of helium-cooled, high-temperature reactors (HTGRs), including the Fort St. Vrain (FSV) HTGR. A reference observed FSV reactor coolant environment was identified. Further, a slightly drier expected FSV coolant chemistry was predicted for reactor operation at 100% of full power. The expected environment was compared with helium test environments used in the US, United Kingdom, Germany, France, and Japan. Based on a comprehensive review and analysis of mechanical property data reported for Alloy 800 tested in controlled-impurity helium environments (and in air when appropriate for comparison), an assessment was made of the effect of FSV expected helium chemistry on material properties of alloy 800, with emphasis on design properties of the Alloy 800 material utilized in the FSV steam generators.
A comprehensive review was conducted of primary helium coolant chemistry data, based on current and past operating histories of helium-cooled, high-temperature reactors (HTGRs), including the Fort St. Vrain (FSV) HTGR. A reference observed FSV reactor coolant environment was identified. Further, a slightly drier expected FSV coolant chemistry was predicted for reactor operation at 100% of full power. The expected environment was compared with helium test environments used in the US, United Kingdom, Germany, France, and Japan. Based on a comprehensive review and analysis of mechanical property data reported for Alloy 800 tested in controlled-impurity helium environments (and in air when appropriate for comparison), an assessment was made of the effect of FSV expected helium chemistry on material properties of alloy 800, with emphasis on design properties of the Alloy 800 material utilized in the FSV steam generators.
The present study answers at the request of the Inspection of the classified installations to see the operator of the G.I.P. Cyceron setting up a plan of environmental radiological surveillance around its installations and including, at a minimal level, the following data: Measures of radioactivity on representative biological indicators and measures of dose rate in the environment close to installations in functioning. Further to the radiological assessment of the terrestrial environment of the G.I.P. Cyceron installations realized at the end of 2003, within the framework of a project of the installations extension, the A.C.R.O. was again required for the implementation of this radiological surveillance for year 2005. The first purpose is to supply elements of appreciation about the impact of these installations on environment and persons. This evaluation participates in radiation protection and allows to make sure that the G.I.P. operator ...
Sandia was presented with an opportunity in 1993 to design containers for the long term storage and transport of fissile material. This program was undertaken at the direction of the US Department of Energy and in cooperation with Lawrence Livermore National Laboratory and Los Alamos National Laboratory which were tasked with developing the internal fixturing for the contents. The hardware is being supplied by Allied Signal Federal Manufacturing and Technologies, and the packaging will occur at Mason and Hangar Corporation`s Pantex Plant. The unique challenge was to design a container that could be sealed with the fissile material contents; and, anytime during the next 50 years, the container could be transported with only the need for the pre-shipment leak test. This required not only a rigorous design capable of meeting the long term storage and transportation requirements, but also resulted in development of a surveillance program to ensure that the container ...
Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery is very desirable. Typically, this imagery has many thousands of pixels on a side and is characterized by lower resolutions (e.g. {approx}0.5 meters/pixel to {approx}2.0 meters/pixel) and lower frame rates (e.g. {approx} sub-Hz to several Hz). We describe our ultra-scale capable implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. This work builds upon an earlier report, where now the algorithm has been modified for improved performance and has been substantially improved to handle much larger datasets in a much shorter time.
Due to changed operational conditions and because of the increasing age of several hydro power plant components, there is an increasing risk of damages and the control of degradation mechanisms is of increasing significance. Therefore lifetime considerations for safety relevant components in pumped-storage plants become more and more important. The development of a lifetime management system, in conjunction with monitoring systems and specific surveillance for a group of pumped-storage power plants of different ages and in a wide range of power output is presented. The special focus is on the impact of fatigue strength considerations within this framework. The applied procedure will be described for typical mechanical components in pumped-storage plants exemplarily. (orig.)
Event-based biosurveillance is a scientific discipline in which diverse streams of data, available from the Internet, are characterized prospectively to provide information on infectious disease events. Biosurveillance complements traditional public health surveillance to provide both early warning of infectious disease events as well as situational awareness. The Global Health Security Action Group (GHSAG) of the Global Health Security Initiative is developing a biosurveillance capability that integrates and leverages component systems from member nations. This work discusses these biosurveillance systems and identifies needed future studies.
The Site Environmental Report is an integrated report on Berkeley Lab's environmental programs to satisfy the requirements of DOE Order 231.1A, Environment, Safety, and Health Reporting. It summarizes Berkeley Lab's environmental management performance, presents environmental monitoring results, and describes significant programs for calendar year 2007. Volume I is organized into an executive summary followed by six chapters that contain an overview of the Laboratory, a discussion of the Laboratory's environmental management system, the status of environmental programs, and summarized results from surveillance and monitoring activities.
Ageing of nuclear power plants means evolution of material or equipment properties on one side, and evolution of personnel skill and procedure adequacy on the other side, both of which, after a certain time, may not be compatible with the required safety provisions, or with an economic operation of the plant. Repair or replacement of components, as well as change in service conditions for a better compatibility with component reduced capabilities can be used to mitigate ageing effects. The paper summarises the results of a study conducted in this field with the support of the European Commission. It presents: the synthesis of the work done under international auspices, and in the European context; the comparison of ageing management approaches used in several European countries with international recommendations; the summary of the various potential phenomena and their governing parameters, the methods of in-service ageing identification and possible mitigation methods; illustrative ...
The measurement of air pollutants is no more sufficient. It is necessary to assess the risk induced by air pollution, and then to put in place actions to reduce it. The air quality monitoring takes into account different pollutants: nitrogen oxides, carbon monoxide, particulates for the traffic; sulfur dioxide and particulates for use of fuel or coal or chemical transformations in air; ozone and nitrogen dioxide from hydrocarbon and nitrogen oxides emissions; the use of simulation methods allow to calculate the concentrations levels for these pollutants taken as indicators. (N.C.)
The multi-frequency binary sequence experimental technique has been implemented at the Fast Flux Test Facility for routine surveillance activities. The frequency content of the standard rod-movement sequence has been shown to be sufficient to normalize the data at moderate frequencies. This obviates the need for auxiliary calibration measurements and provides the reactivity worth of the test control rod. Analyses of a series of tests conducted in 1986 illustrate that the rod worths inferred from the tests are consistent with zero-power measurements. Also, the dependence of the prompt feedback time constant on reactor conditions was determined.
Although the majority of men presenting with non-seminomatous germ cell tumours (NSGCT) are cured, late relapse (occurring more than 2 years after obtaining a complete response to treatment) is increasingly recognized. The typical patterns of disease spread have been well-documented, but the findings at late relapse are more variable and less well-described. We discuss the phenomenon of late relapse, the characteristics of teratoma differentiated (TD), and the issue of long-term imaging surveillance of patients with NSGCT. The potential sites of late relapse of NSGCT and the associated spectrum of imaging appearances are illustrated.
Although the majority of men presenting with non-seminomatous germ cell tumours (NSGCT) are cured, late relapse (occurring more than 2 years after obtaining a complete response to treatment) is increasingly recognized. The typical patterns of disease spread have been well-documented, but the findings at late relapse are more variable and less well-described. We discuss the phenomenon of late relapse, the characteristics of teratoma differentiated (TD), and the issue of long-term imaging surveillance of patients with NSGCT. The potential sites of late relapse of NSGCT and the associated spectrum of imaging appearances are illustrated.
Event-based biosurveillance is a scientific discipline in which diverse sources of data, many of which are available from the Internet, are characterized prospectively to provide information on infectious disease events. Biosurveillance complements traditional public health surveillance to provide both early warning of infectious disease events and situational awareness. The Global Health Security Action Group of the Global Health Security Initiative is developing a biosurveillance capability that integrates and leverages component systems from member nations. This work discusses these biosurveillance systems and identifies needed future studies.
DescriptionM291272: National herpetofauna monitoring programme: map-based online data entry and volunteer training, 2008 1. Background The Herpetological Conservation Trust (the HCT) has been working in partnership with Natural England and others, including the voluntary Amphibian and Reptile Groups of the UK (ARG UK), to develop a national surveillance system for herpetofauna. The National Amphibian and Reptile Recording Scheme (NARRS) is an umbrella for existing survey initiatives as well as new schem [continued...
The Savannah River Site (SRS), one of several U.S. Department of Energy (DOE) facilities, produces nuclear materials for national defense and for other government and civilian uses. SRS ceased production of defense materials in 1988, and the site's main activities now involve waste management and environmental restoration. These programs have generated extensive effluent monitoring and environmental surveillance programs for the Environmental Monitoring Section (EMS), which performs #approx#105,000 radiological analyses on 30,000 samples a year. Gamma spectroscopy is performed on an estimated 10,000 samples annually. This report describes a program to develop and improve the EMS system.
In November 1977, 627 soldiers belonging primarily to the First Battalion, 82nd Airborne Division, stationed at Fort Bragg, were sent to the Canal Zone, Panama, for jungle warfare training. A medical surveillance program incorporating pre- and post-evaluations over a 6-month period with dermatologic examinations, questionnaires, and serologic tests was established. Ten cases of cutaneous leishmaniasis (1.6/100 men) were diagnosed by positive Leishmania culture. The demonstrated lack of sensitivity and specificity of the indirect fluorescent antibody test and the direct agglutination test render these serological methods useless as diagnostic screening methods in the early stages of this disease. PMID:7406101
Chemical composition of fine aerosol particles over the northern Chilean coastal waters was determined onboard the U.S. DOE G-1 aircraft during the VOCALS (VAMOS Ocean-Cloud-Atmosphere-Land Study) field campaign between October 16 and November 15, 2008. SO42-, NO3-, NH4+, and total organics (Org) were determined using an Aerodyne Aerosol Mass Spectrometer, and SO42-, NO3-, NH4+, Na+, Cl-, CH3SO3-, Mg2+, Ca2+, and K+ were determined using a particle-into-liquid sampler-ion chromatography technique. The results show the marine boundary layer (MBL) aerosol mass was dominated by non- sea-salt SO42- followed by Na+, Cl-, Org, NO3-, and NH4+, in decreasing importance; CH3SO3-, Ca2+, and K+ rarely exceeded their respective limits of detection. The SO42- aerosols were strongly acidic as the equivalent NH4+ to SO42- ratio was only ~0.25 on average. NaCl particles, presumably of sea-salt origin, showed chloride deficits but retained Cl- typically more than half the ...
The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduce...
Correlations between structural aspects of solid materials and their behavior as catalysts are relatively recent. This 20-chapter book focuses on understanding of solid-state mechanisms in heterogeneous catalysis and relationship between catalytic behavior and solid state structure, emphasizing catalysis with oxides, sulfides, and zeolites.
Enediynes are potent antitumor antibiotics that are classified as 9- or 10-membered according to the size of the enediyne core structure. However, almost nothing is known about enediyne core biosynthesis,...Full Text Available
During the past 3 years, progress was made in elucidating the excited state structures of Pt(diimine)(dithiolate) complexes, while more recent efforts focused on the photochemistry of these complexes and electronic structure of other dithiolate systems. A carbonyl-Ir-maleonitrile dithiolate complex is also studied.
The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, alloys, intermetallic compounds, sulfides, and ...
In the State Laboratory of North Rhine-Westphalia for Food, Pharmaceutical and Environmental Chemistry (Chemisches Landesuntersuchungsamt), more than 600 individual human milk samples have been analyzed...Full Text Available
Progress is reported in the following subject areas: (1) chemistry of the arogenate molecule; (2) plant enzymology at the organismal level; (3) isolation of regulatory mutants in tobacco; and (4) stability of the haploid state in Nicotiana sylvestris.
Research programs on coal liquefaction are presented. Major topics include: coprocessing, two-stage liquefaction, low severity liquefaction, coal/catalyst and liquefaction chemistry. Individual projects are processed separately for the data bases. (CBS)
Low resolution and un-sharp facial images are always captured from surveillance videos because of long human-camera distance and human movements. Previous works addressed this problem by using an active camera to capture close-up facial images without considering human movements and mechanical delays of the active camera. In this paper, we proposed a unified framework to capture facial images in video surveillance systems by using one static and active camera in a cooperative manner. Human faces are first located by a skin-color based real-time face detection algorithm. A stereo camera model is also employed to approximate human face location and his/her velocity with respect to the active camera. Given the mechanical delays of the active camera, the position of a target face with a given delay can be estimated using a Human-Camera Synchronization Model. By controlling the active camera with corresponding amount of pan, tilt, and zoom, a clear ...
A variety of surveillance operations require the ability to track vehicles over a long period of time using sequences of images taken from a camera mounted on an airborne or similar platform. In order to be able to see and track a vehicle for any length of time, either a persistent surveillance imager is needed that can image wide fields of view over a long time-span or a highly maneuverable smaller field-of-view imager is needed that can follow the vehicle of interest. The algorithm described here was designed for the persistence surveillance case. In turns out that most vehicle tracking algorithms described in the literature[1,2,3,4] are designed for higher frame rates (> 5 FPS) and relatively short ground sampling distances (GSD) and resolutions ({approx} few cm to a couple tens of cm). But for our datasets, we are restricted to lower resolutions and GSD's ({ge}0.5 m) and limited frame-rates ({le}2.0 Hz). ...
Volume 2 of the water resources data for the 1992 water year for Oklahoma consists of record of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes or reservoirs; and water levels of ground-water well. The report contains discharge records for 136 gaging stations; stage and contents for 31 lakes or reservoirs; water quality for 50 gaging stations. Also included are 61 partial-record or miscellaneous streamflow stations and 28 ground-water sites.
The interaction between a pair of counter-rotating vortices and a lean premixed CH{sub 4}/O{sub 2}/N{sub 2} flame ({Phi} = + 0.55) has been studied by direct numerical simulations using detailed and reduced chemical reaction schemes. Results from the complex chemistry simulation are discussed with respect to earlier experiments and differences in the simulations using detailed and reduces chemistry are investigated. Transient evolutions of the flame surface and the total heat release rate are compared and modifications in the evolution of the local flame structure are displayed. (authors) 22 refs.
The nine papers presented at this conference cover the following topics: the systematization, condensed description, and prediction of sets of anion exchange extraction constants on the basis of their statistical computer treatment; characteristics and uses of solid extractants containing D2EHPA and TBP for separating the transplutonium elements; enrichment of americium 242m and americium 242 by the Szilard-Chalmers method; an x-ray diffraction pattern analysis for transplutonium compounds; the radiation chemistry of americium; and the effects of alpha irradiation on the behavior of americium in perchlorate solutions.
A review is given of the state of knowledge of the chemistry of astatine with the oxidation number +1. According to the position in the periodic system, astatine has metalloidal properties. The existence of a singly-charged cation in acid solution and the complex formation reactions with halide ions (Cl"-, Br"-, and I"-), with pseudohalide ions (SCN"-, CN"-, C(CN)_3"-, and N_3"-), and with thioureas and their derivatives underline the metalloidal character of At(I). Optimal preparation conditions, chemical composition of astatine compounds, existence and stability regions of At(I) complexes, and stability constants have been investigated by means of electromigration in free electrolyte solutions.
Silicon nitride hybrid ball bearings used in high temperature applications undergo mechanical and environmental degradation. To study the surface chemistry of silicon nitride, a CAChe{trademark} Worksystem* has been used to generate the clusters and corresponding transmission vibrational spectra of silicon nitride. In the present study, the effect of surface conditions on the surface chemistry and wear degradation of silicon nitride was evaluated. Infrared reflection spectroscopy (IRRS) used to determine molecular orientations shows a difference in reflectance spectra for fractured and as-received.
The principles of modern pesticide residue chemistry were articulated in the 1950s. Early authors pointed out the advantages of systematizing and standardizing analytical methods for pesticides so that they could be widely practiced and the results could be reproduced from one laboratory to the next. The availability of improved methods has led to a much more complete understanding of pesticide behavior and fate in foods and the environment. Using methods based largely upon gas chromatography (GC) and high-performance liquid chromatography (HPLC) coupled increasingly with mass spectrometry (MS) and MS(n) as the detection tool, residues can be measured at parts per billion levels and below in a variety of food and environmental matrices. Development of efficient extraction and cleanup methods, techniques such as ELISA, efficient sample preparation techniques such as QuEChERS, and automated laboratory and field instrumentation has also contributed to the tools ...
Two plasma chemistries, i.e., CH{sub 4}/H{sub 2}/Ar and Cl{sub 2}/Ar, were compared for the etching of InGaP, AlInP, and AlGaP under inductively coupled plasma (ICP) conditions. While the etching with CH{sub 4}/H{sub 2}/Ar discharges appears to be ion driven, Cl{sub 2}/Ar discharges showed an additional strong chemical enhancement. The highest etch rate ({approximately}1 {mu}m/min) for InGaP was achieved at high ICP source power ({ge}750 W) with the Cl{sub 2}/Ar chemistry. Cl{sub 2}/Ar discharges provided very smooth surfaces in all three materials with root-mean-square roughness measured by atomic force microscopy around 2 nm. This result may be due to the efficient ion-assisted product desorption in this chemistry. The etched near-surface region of InGaP ({approximately}100 {Angstrom}) with Cl{sub 2}/Ar maintained almost the same stoichiometry as that of the unetched control. By contrast, the CH{sub 4}/H{sub 2}/Ar plasma ...
Water-resources data for the 1993 water year for Minnesota consists of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This volume contains discharge records for 58 gaging stations; stage and contents for 9 lakes and reservoirs; water quality 15 stream stations, 1 lakes station, 1 precipitation station, and water levels for 15 observation wells. Also included are 61 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are pulished as miscellaneous measurements.
Water-resources data for the 1991 water year for Minnesota consist of records of stage, discharge and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. The volume contains discharge records for 60 gaging stations; stage and contents for 9 lakes and reservoirs; water quality for 18 stream stations, 1 lake station, 22 partial-record sites, 1 precipitation station, 108 wells; and water levels for 119 observation wells. Also included are 59 high-flow partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program and are published as miscellaneous measurements or low-flow investigations.
In the National Water Plan it is described which measures must be taken to keep the Netherlands safe and livable for future generations and to make use of the chances offered by water.
swimmers in or around the water. Designate a responsible adult who can swim and knows CPR to watch swimmers in or around water. The supervisor should not be involved in any...
This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division (CTD) at Oak Ridge National Laboratory (ORNL) during the period January--March 1997. Created in March 1997 when the CTD Chemical Development and Energy Research sections were combined, the Chemical and Energy Research Section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within seven major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Molten Salt Reactor Experiment (MSRE) Remediation Studies, Chemistry Research, Separations and Materials Synthesis, Solution Thermodynamics, and Biotechnology Research. The name of a technical ...
The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate ...
Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI{sub 3} or BBr{sub 3} discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates ({gt}6000thinsp{Angstrom}thinspmin{sup {minus}1}) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI{sub 3} or BBr{sub 3} content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO{sub 2} and SiN{sub x} of {ge}8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. {copyright} {ital 1998 American Vacuum Society.}
Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI_3 or BBr_3 discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates (>6000 Angstrom min"-"1) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI_3 or BBr_3 content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO_2 and SiN_x of #>=#8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. copyright 1998 American Vacuum Society.
Aims: The production of saturated organic molecules in hot cores and corinos is not well understood. The standard approach is to assume that, as temperatures heat up during star formation, methanol and other species evaporate from grain surfaces and undergo a warm gas-phase chemistry at 100 K or greater to produce species such as methyl formate, dimethyl ether, and others. But a series of laboratory results shows that protonated ions, typical precursors to final products in ion-molecule schemes, tend to fragment upon dissociative recombination with electrons rather than just ejecting a hydrogen atom. Moreover, the specific proposed reaction to produce protonated methyl formate is now known not to occur at all. Methods: We utilize a gas-grain chemical network to probe the chemistry of the relatively ignored stage of hot core evolution during which the protostar switches on and the temperature of the surrounding gas and dust rises from 10 K to ...
We report on the contents and results for 360 students of a mathematics assessment administered at the start of the second-semester introductory chemistry course required for science and engineering majors at the University of Minnesota. This calculator-free, 20-question, 30-minute, multiple-choice, diagnostic quiz includes questions selected specifically for their relevance to this course, concerning logarithms, scientific notation, graphs, and algebra. For the 325 students in degree-granting programs, significant correlations are reported between their mathematics assessment scores and success in this course, as measured by performance on exams (for which scientific calculators were permitted) and course grades. These observations suggest that responses to the simple questions on this unannounced quiz have some predictive utility as signatures of underlying thinking and learning patterns that are associated with success in this course. In addition, we argue that ...
Courses in Ceramic Engineering from the Course Catalog at the University of Illinois at Urbana-Champaign. List includes: CER E 299. Senior Thesis CER E 320. Ceramic Materials and Properties CER E 321. Ceramic Processing and Microstructure Development CER E 322. Process Design CER E 323. Ceramic Engineering Processing Laboratory CER E 324. Refractory Technology CER E 326. Chemistry and Technology of Glass CER E 327. Ceramic Microscopy CER E 328. Electrical Ceramics CER E 330. Chemically Bonded Ceramics CER E 390. Special Topics in Ceramics CER E 420. Ceramic Chemistry CER E 422. Dielectric Properties of Ceramic Materials CER E 425. Physical Chemistry of Clays and Soils CER E 426. Mineralogy of Clays CER E 427. Petrology of Clay Minerals CER E 429. Seminar in Ceramics CER E 497. Research Seminars CER E 499. Thesis Research.
The use of cement based systems for solidification and stabilization of hazardous wastes has been proposed. The stabilization of Cr contaminated paint removal wastes in ordinary Portland cement and in a Portland cement and blast furnace slag matrix was investigated. A loading by volume of 75% waste and 25% cement (or cement + slag) was used. The expression of pore solution was utilized to determine the chemical environment encountered by the waste species in the cement matrix. The highly alkaline conditions of ordinary Portland cement determined the stability of the metal species, with Cr being highly soluble. The replacement of 25% of the Portland cement by blast furnace slag was found to decrease the [OH-] of the pore solution resulting in a decrease of the Cr concentration. For cement wastes forms hydrated for 28 days, the Cr concentration decreased in the expressed pore solution. During the TCLP tests the cement waste form and extraction solution were found to react, changing the ...
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 Pole ozone hole appeared after the middle in the twenty-first ...
The history of the urinary test papers does not being in the post-war period. As early as the 1880's some practitioners and pharmacists tried to replace the complicated wet-chemical procedures and apparatus by "dry chemistry." The first popular test paper for sugar and albumin originated in England in 1883. Dry reagents for proving hematuria have been available since the beginning of this century. Until the 1930s a wide palette of commercial urine tests with "modern" brand names was established. A methodological breakthrough was created by the spot test chemistry inaugurated by the Austrian, Fritz Feigl, about 1920. Using the capillary properties of filter paper in enhancing color reactions he founded a new area of analytical chemistry. Many of the pioneers were recruited from Jewish scientists. In this lecture is proposed that their emigration and banishment as well as the Second World War have stopped the development of ...
Preterm children born before 32 weeks of gestation represent 1% of the annual births in Switzerland, and are the most at risk of neurodevelopmental disabilities. A neurological surveillance is thus implemented in the neonatal units, and multidisciplinary neurodevelopmental follow-up is offered to all our preterm patients. The follow-up clinics of the University hospitals in Lausanne and Geneva follow the Swiss guidelines for follow-up. An extended history and neurological examination is taken at each appointment, and a standardized test of development is performed. These examinations, which take place between the ages of 3 months and 9 years old, allow the early identification and treatment of developmental disorders frequent in this population, such as motor, cognitive or behavioral disorders, as well as the monitoring of the quality of neonatal care. PMID:21452511
Based on the enhanced cooperation between Republic of Korea (ROK) and International Atomic Energy Agency (IAEA), IAEA installed new safeguards equipment (Unattended Monitoring System, UMS) at Wolsung unit 2 on January, 2005. The UMS was utilized in parallel with traditional human surveillance during the transfer campaign of Wolsung unit 2 (7 March - 22 July). Installation of UMS at all Wolsung units will be decided on the basis of the result of this test. The transfer campaign with UMS at Wolsung units 2 and 4 was started from September 1, 2006 at the same time. Implementation of UMS to the transfer campaign in Wolsung site will be considerably reduced the IAEA's inspection effort and burden of operator.
Based on the enhanced cooperation between Republic of Korea (ROK) and International Atomic Energy Agency (IAEA), IAEA installed new safeguards equipment (Unattended Monitoring System, UMS) at Wolsung unit 2 on January, 2005. The UMS was utilized in parallel with traditional human surveillance during the transfer campaign of Wolsung unit 2 (7 March - 22 July). Installation of UMS at all Wolsung units will be decided on the basis of the result of this test. The transfer campaign with UMS at Wolsung units 2 and 4 was started from September 1, 2006 at the same time. Implementation of UMS to the transfer campaign in Wolsung site will be considerably reduced the IAEA's inspection effort and burden of operator.
Purpose To evaluate disease failure patterns and overall survival (OS) of women with triple-negative (TN) breast cancer who underwent breast-conserving therapy (BCT) and to understand the relationship of TN tumors with other prognostic factors. Patients and Methods The Surveillance, Epidemiology, and End Results (SEER) registry identified 562 women diagnosed and/or treated with unilateral invasive breast cancer during 2003?2004 at three Emory hospitals. After medical record review, 193 eligible women, with all tumor types, received BCT. Primary endpoints (local, regional, and distant recurrences) and secondary endpoint (OS) were evaluated using chi-square tests and Cox proportional hazards models. Results Of the 193 women, 33 (17.1%) had TN tumors and 160 (82.9%) had non-TN tumors. Patient...
Objectification theory contends that women are socialized to view their body as an object to be evaluated by others (Fredickson and Roberts 1997). In contrast, pregnancy may be a time that women are more attuned to their body?s functionality. Extending objectification theory, we investigate relationships among body surveillance, awareness and appreciation of body functionality, depressive symptoms, and prenatal health behaviors among an on-line sample of 156 predominantly White, middle-class pregnant women from throughout the U.S recruited through maternity stores, message boards, listservs, and snowballing techniques. We examine whether higher levels of awareness and appreciation of body functionality may attenuate, and thereby possibly protect women from the negative effects of high body...
Introduction: Patients in underdeveloped nations have limited access to life-saving medical technology including cardiac rhythm management (CRM) devices. We evaluated alternative means to provide such technology to this patient population while assessing the safety and efficacy of such a practice. Methods: Patients in the United States with clinical indications for extraction of CRM devices were consented. Antemortem CRM devices were cleaned and sterilized following a protocol established at our institution. Surveillance in vitro cultures were performed for quality assurance. The functional status of pulse generators was tested with a pacing system analyzer to confirm at least 70% battery life. Most generators were transported, in person, to an implanting institution in Nicaragua. Recipien...
Weld metal, base material and stainless steel overlay specimens for Charpy tests and static tensile tests were irradiated for a year in a power reactor of the Bohunice nuclear power plant in place of the evaluated surveillance specimens. The material of the specimens was identical with that of the WWER-440 reactor pressure vessels, and was exposed to a fluence of (1.2 - 4.5) x 10"2"3 m"-"2 (E > 0.5 MeV) at approximately 270 degC. Some of the irradiated as well as unirradiated specimens were subjected to regeneration annealing at 475 degC for 168 h. The behavior of the materials after irradiation and annealing was evaluated. (author). 33 tabs., 32 figs., 8 refs.
A better understanding of the immune processes in the pathogenesis and progression of prostate cancer (CaP) may point the way towards improved treatment modalities. The challenge is to amplify immune responses to combat tumour escape mechanisms. Infection and inflammation may have a role in prostate carcinogenesis, including the newly discovered xenotropic murine leukaemia virus (XMRV). These inflammatory states damage defence mechanisms and induce a high proliferative state favouring further mutation and impaired immune surveillance. With this knowledge we are able to explore the use of immunotherapy to rejuvenate the immune system in combating CaP. Recently Sipuleucel-T, an immunotherapeutic agent for metastatic androgen independent CaP, has resulted in improved survival and might be the...
In the paper we investigate a mathematical model describing the growth of tumor in the presence of immune response of a host organism. The dynamics of tumour and immune cells is based on the generic Michaelis-Menten kinetics describing interaction and competition between the tumour and the immune system. The appropriate phenomenological equation modeling cell-mediated immune surveillance against cancer is of the predator-prey form and within a given choice of parameters exhibits bistability. Under the influence of spontaneous weak fluctuations, the model may be analyzed in terms of a stochastic differential equation bearing the form of an overdamped Langevin-like dynamics in the external quasi-potential represented by a double well. We analyze properties of the system within the range of parameters for which the potential wells are of the same depth and when the additional perturbation describing a periodic treatment is insufficient to overcome the barrier height ...
Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth's ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can be used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the second year, which include completion of the new models for the equatorial region and initial development of models for the high latitude (auroral and polar cap) region.
The aim of this review is to evaluate the role of inflammatory spine disease in patients with chronic back pain. The contribution of imaging modalities for the diagnostic evaluation of back pain is discussed. A systematic literature search based on the classification of seronegative spondyloarthropathies and rheumatoid arthritis was performed. The results of this search and the experiences in a large collective of rheumatological patients are analyzed. The prevalence of rheumatoid arthritis (1-2%) is comparable to that of spondyloarthropathies (1.9%). The etiology of these entities is not fully elucidated. Magnetic resonance imaging is increasingly used for early detection and surveillance of therapy with TNF-#alpha# antagonists. Bone marrow edema, which is only detectable with MRI, represents an early sign of inflammation. Therapy with TNF-#alpha# antagonists is based on clinical and laboratory criteria, and signs of inflammation in MRI. MRI is useful for ...
Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth`s ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can he used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the third year of this project, which includes completion of the new model for the high-latitude (auroral and polar cap) region of the WBMOD model.
The author explains current developments in high voltage cable technology and subsequently describes problems inherent in its application, from the users viewpoint, in municipal electricity supply. The planning of a high voltage cable network and the selection of a specific type of cable are not only dependent on the typical properties of various cables but to a major degree also on the feasible laying technique, the power transmitted, the costs, the stellation treatment of the high voltage network, the acceptance requirement, the inductive influence from telecommunication cable, thermal influences from the environment, eventual safeguards from mechanical and chemical damage to the network, frequency of failure and surveillance and breakdown location. In conclusion, the author portrays potential developments in the fields of high and maximum voltage cable from the perspectives of today.
The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.
The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.
A systematic study of the effects of environmental factors on nylon 66 and Kevlar 29 strength degradation in parachute components is being conducted at Sandia National Laboratories. It includes: (1) accelerated aging studies in air, inert environments, humidity, ozone, and smog; (2) a 25-year surveillance program of parachutes in a variety of natural climatic environments; (3) moisture absorption as a function of humidity; (4) effects of surface coatings normally applied to parachutes; and (5) development of nondestructive evaluation techniques which can be used to map mechanical properties over the entire parachute surface. The accelerated aging and moisture absorption studies show that air, humidity, and smog contribute to degradation. Chemiluminescence, gas chromatographic pyrograms, and uv spectroscopy show promise as nondestructive evaluation techniques.
Unmanned Aerial Vehicles (UAV) are being proposed for many applications including surveillance, mapping and atmospheric studies. These applications require a lightweight, low speed, medium to long duration airplane. Due to the weight, speed, and altitude constraints imposed on such aircraft, solar array generated electric power is a viable alternative to air-breathing engines. Development of such aircraft is currently being funded under the Environmental Research Aircraft and Sensor Technology (ERAST) program. NASA Lewis Research Center (LeRC) is currently building a Solar Electric Airplane to demonstrate UAV technology. This aircraft utilizes high efficiency Applied Solar Energy Corporation (ASEC) GaAs/Ge space solar cells. The cells have been provided by the Air Force through the ManTech Office. Expected completion of the plane is early 1995, with the airplane currently undergoing flight testing using battery power.
Abstract Background: This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n == 9), Finland (n == 10), Norway (n == 7) and Sweden (n == 19). Methods: The hospitals were each asked to test 30 consecutive Gram-positive and 30 Gram-negative clinical isolates. Supportive information accompanying each isolate included the study centre, ward level (PCC, GHW, or ICU), patient identification and source of the isolate. Minimum inhibitory concentrations (MICs) for tetracycline and tigecycline were determined with the Etest. Results: The isolates collected comprised 1610 Gram-negative and 1767 Gram-positive clini...
In 1993, the US Department of Energy (DOE) decided to shut down the Fast Flux Test Facility (FFTF) due to lack of national missions that justified the annual operating budget of approximately $88M/year. The initial vision was to ''deactive'' the facility to an industrially and radiologically safe condition to allow long-term, minimal surveillance storage until approximately 2045. This approach would minimize near term cash flow and allow the radioactive decay of activated components. The final decontamination and decommissioning (D and D) would then be performed using then-current methodology in a safe and efficient manner. the philosophy has now changed to close coupling the initial deactivation with final D and D. This paper presents the status of the facility and focuses on the future challenge of sodium removal.
AbstractBACKGROUND: Disparities in treatment and mortality for colorectal cancer (CRC) may reflect differences in access to specialized care or other characteristics of the area where an individual lives. METHODS: Surveillance, Epidemiology and End Results Program-Medicare data for seniors diagnosed with CRC were linked to area measures of the sociodemographic characteristics and the capacity of surgeons, medical oncologists, and radiation oncologists. Outcomes included receipt of stage-appropriate CRC care and mortality. RESULTS: After adjustment, blacks and Hispanics were less likely than whites to undergo surgery (odds ratio [OR] 0.57, 95% confidence interval (CI) 0.52-0.63 and OR 0.82, 95% CI 0.70-0.95, respectively). Individuals who lived in areas with the highest tertile of surgeon c...
A growing number of applications that generate massive streams of data need intelligent data processing and online analysis. Real-time surveillance systems, telecommunication systems, sensor networks and other dynamic environments are such examples. The imminent need for turning such data into useful information and knowledge augments the development of systems, algorithms and frameworks that address streaming challenges. The storage, querying and mining of such data sets are highly computationally challenging tasks. Mining data streams is concerned with extracting knowledge structures represented in models and patterns in non stopping streams of information. Generally, two main challenges are designing fast mining methods for data streams and need to promptly detect changing concepts and data distribution because of highly dynamic nature of data streams. The goal of this article is to analyze and classify the application of diverse data mining techniques in ...
Objective Infectious endophthalmitis is among the most serious complications of cataract surgery. Gram-negative bacteria, including Pseudomonas aeruginosa, are responsible for less than 30% of cases; however, their rapidity of infection and virulence often results in poor visual outcome despite prompt antibiotic treatment. The purpose of this study was to investigate an outbreak of post-cataract surgery P. aeruginosa endophthalmitis in India. Design Hospital-based case series. Participants Twenty patients with acute postoperative endophthalmitis who underwent cataract surgery at one of the peripheral centers of Joseph Eye Hospital, Tiruchirapalli, Tamil Nadu, India, from February 23 to April 2, 2008. Interventions Vitreous aspirates and environmental surveillance specimens were inoculated ...
In 2001, the U.S. Department of Energy (DOE), National Nuclear Security Administration (NNSA/NSO) remediated six areas associated with Amchitka mud pit release sites located on Amchitka Island, Alaska. This included the construction of seven closure caps. To ensure the integrity and effectiveness of remedial action, the mud pit sites are to be inspected every five years as part of DOE's long-term monitoring and surveillance program. In August of 2006, the closure caps were inspected in accordance with the ''Post-Closure Monitoring and Inspection Plan for Amchitka Island Mud Pit Release Sites'' (Rev. 0, November 2005). This post-closure monitoring report provides the 2006 cap inspection results.
Environmental surveillance and public information are translated in 2000 by numerous actions. To improve the public information, A.C.R.O. concerns its main efforts on the development of the consumer technical information available on-line via its web site and in its regular publication 'the nuclear chronicle'. A new publication, the A.C.R.O. journal is made to answer to more acute questions as waste burying. Besides, the participation of the A.C.R.O. at various local commissions of information (C.L.I.) as well as at the superior council of the safety and nuclear information ( C.S.S.I.N.) stays an essential action. (N.C.)
Free Topology Network technology provides cost reduction benefits as well as flexibility in safeguards applications. Power line communications technologies have proven viability for transmission and reception of safeguards data, including surveillance photographs, the source of the largest data files. In the future, enhancements will be made to the technology that should boost both performance and flexibility. Work is already underway to achieve higher data rates over power line communications eventually, it should be possible to reach data rates of one million bits per second or higher. Also, the use of technologies such as Novell Embedded Systems Technology (NEST) and Echelon LON technology will allow a greater number of safeguards technologies to become resident on the Free Topology Safeguards Network.
Free Topology Network technology provides cost reduction benefits as well as flexibility in safeguards applications. Power line communications technologies have proven viability for transmission and reception of safeguards data, including surveillance photographs, the source of the largest data files. In the future, enhancements will be made to the technology that should boost both performance and flexibility. Work is already underway to achieve higher data rates over power line communications eventually, it should be possible to reach data rates of one million bits per second or higher. Also, the use of technologies such as Novell Embedded Systems Technology (NEST) and Echelon LON technology will allow a greater number of safeguards technologies to become resident on the Free Topology Safeguards Network.
An improved process is disclosed for reducing the water content of coal containing bound water by releasing at least a portion of the bound water by maintaining the coal at a temperature from about 220/sup 0/ to about 500/sup 0/ F. in the presence of water at a pressure sufficient to maintain at least portion of the water in a liquid phase for a time sufficient to release at least a portion of the bound water wherein the improvement comprises contacting the coal during such treatment with an active material selected from the group consisting of carboxylic organic acids containing up to about 6 carbon atoms, phenol, phenolic acids and inorganic acids.
In the United States, economic growth increasingly requires that greater volumes of freshwater be made available for new users, yet supplies of freshwater are already allocated to existing users. Currently, water for new users is made available through re-allocation of xisting water supplies-for example, by cities purchasing agricultural water rights. Water may also be made available through conservation efforts and, in some locales, through the development of ''new'' water from non-traditional sources such as the oceans, deep aquifer rackish groundwater, and water reuse.
Jet Propulsion Laboratory. California Institute of Technology. Pasadena, California. Energy and Water Conservation. Steve Rigdon. Facilities Energy Manager ...
...The+Wiley+Encyclopedia+of+Packaging+Technology%2C+3rd+Edition FO21+Food+Packaging Wiley::The Wiley Encyclopedia of Packaging Technology, 3rd Edition WILEY ...US | HELP Home / Chemistry / Food Science & Technology / Food Processing, Production & Manufacture / Food Packaging / The Wiley Encyclopedia of Packaging Technology, 3rd Edition ...Manufacture Sensory Science Food Biotechnology Food Chemistry Food Engineering Related Titles Food Packaging Brewing Yeast and Fermentation by Chris Boulton, David Quain Food ...Editor) Journal of Food Process Engineering Journal of Food Processing and Preservation Packaging Research in Food Product Design and Development by Howard R. ...
This review describes how a mismatch between the knowledge produced by scientists and the evidence demanded by regulators has emerged, and how society has struggled to find definitive answers to questions of safety, for an important flame retardant chemical in current use ? Deca-BDE. This has involved two key disciplines: analytical chemistry and toxicology. Within the chemistry, a lack of standardized methodologies among scientists has resulted in a persistent yet largely undeclared failure to replicate results within the discipline. Within the toxicology, the quest for innovative, curiosity-driven research by university scientists in preference to using validated standard protocols, designed to promote consistency within the risk assessment process, has prompted questions about the credi...
Advances in the theory and practice of stress corrosion cracking (SCC) are reviewed for the period 1965-1990. The proceedings of two landmark conferences are used as a basis for discussion: Ohio State University (1967) and Kohler, WI (1988). The discussion is developed around the following topics: metal-environment combinations, testing, fractography, metallurgical aspects, electrochemical aspects and crack chemistry, mechanisms, and prediction and mitigation. It is concluded that the main developments since 1967 are the recognition of the lack of specificity of SCC environments, the use of slow strain rate and fracture mechanics testing, quantitative SEM fractography, studies of grain boundary structure and compositions, transient electrochemistry of bare metal surfaces, measurement and modelling of crack chemistry, elaboration of several SCC models, including slip-dissolution and film induced cleavage, and mitigation by alloy development or ...
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...
The Pacific white shrimp, Litopenaeus vannamei, is the most important shrimp species in volume in world aquaculture. However, in recent decades, outbreaks of diseases, especially viral diseases, have led to significant economic losses, threatening the sustainability of shrimp farming worldwide. In 2004, Brazilian shrimp farming was seriously affected by a new disease caused by the Infectious myonecrosis virus (IMNV). Thus, disease control based on rapid and sensitive pathogen detection methods has become a priority. In this study, a specific quantitation method for IMNV was developed using real-time PCR with SYBR Green chemistry and viral load of the principal target tissues of chronically infected animals was quantified. The quantitative analysis revealed that mean viral load ranged from ...
The recent acceleration of effort to elucidate and explore the coordination chemistry of technetium has been prompted mainly by the need for a new generation of radiotracers in nuclear medicine, preferentially for tomograhic studies. Current approaches and their limitations in designing "9"9"mTc complexes capable of penetrating cell membranes of the target organs, and remaining there sufficiently long, are reviewed. With the predominance of Tc(V) oxo compounds, especially for brain imaging agents, new N4 and N2S2 coordinate complexes have been developed by shifting from bidentate to tetradentate ligands with a variable side chain or other adjustable reactivity. The search for myocardial imaging agents has focused on a variety of mixed ligand complexes of Tc(III) and most promising [Tc(CNR)_6]"+ complexes of Tc(I). 64 refs. (author).
Nuclear approaches for compositional characterization has bright application prospect in forensic perspective towards assessment of nature and origin of seized material. The macro and micro physical properties of nuclear materials can be specifically associated with a process or type of nuclear activity. Under the jurisdiction of nuclear analytical chemistry as well as nuclear forensics, thrust areas of scientific endeavor like determination of radioisotopes, isotopic and mass ratios, analysis for impurity contents, arriving at chemical forms/species and physical parameters play supporting evidence in forensic investigations. The analytical methods developed for this purposes can be used in international safeguards as well for nuclear forensics. Nuclear material seized in nuclear trafficking can be identified and a profile of the nuclear material can be created
We summarize and extend recent work on the theory of extrasolar giant planets (EGPs) and brown dwarfs, paying particular attention to Gliese 229 B, the albedos of EGPs, the compositions of substellar atmospheres, the connections with the giant planets in the solar system, cloud physics, and non-gray spectral synthesis. The role of condensates in altering the optical spectrum of Gliese 229 B is explored, as are the systematics of the reflection spectra from extrasolar giant planets near their primaries. In addition, we discuss the role of convection and disequilibrium chemistry in explaining the anomalous detection of CO in Gliese 229 B. Throughout, we highlight the distinctive chemistry that defines this new class of objects and set goals for future study.
The development of 'Green Chemistry' requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.
The author analyzes conference materials, emphasizing the studies and latest developments useful for industrial heterogeneous catalysis in view of the requirements of green chemistry. Industrial catalysts is developing along a nanometer scale, so especial attention is devoted to analyzing the reports in the Nanochemistry section on the creation of nanocatalysts, the production of active phase nanoparticles, and the formation of new synthesized material properties. The catalysts developed earlier by Russian research in cooperation with Belarusian scientists are considered, and it is shown that not only are expensive nanocontacts extremely promising for industry, but the efficient and economic low-percentage new generation of nanocatalysts synthesized by wet chemistry and containing nanopart...
Chapter one is a review of the relevant literature. In chapter two the coordination chemistry of biphenyl-tailed terpyridines with octahedral metal dications is investigated. The effect of different metal ions on their aggregation modes in the solid state is also investigated. In chapter three the coordination chemistry of polyaryl-tailed terpyridines with octahedral metal dications is investigated. The effect of different aryl tails on their aggregation modes in the solid state is investigated. In chapter four the pi-pi aggregation of molecular boxes through biphenyl tails is studied. In chapter five the immobilisation of aryl tailed complexes into polyelectrolyte films has been investigated, and the arrangement of these complexes in the films has been compared with same complexes in the crystal, thus moving from three dimensional aggregation to two dimensions.
Transition-metal chemistry in ionic liquids (IL) has achieved intrinsic fascination in the last few years. The use of an IL as environmental friendly solvent, offers many advantages over traditional materials synthesis methods. The change from molecular to ionic reaction media leads to new types of materials being accessible. Room-temperature IL have been found to be excellent media for stabilising transition-metal clusters in solution and to crystallise homo- and heteronuclear transition-metal complexes and clusters. Furthermore, the use of IL as solvent provides the option to replace high-temperature routes, such as crystallisation from the melt or gas-phase deposition, by convenient room- or low-temperature syntheses. Inorganic IL composed of alkali metal cations and polynuclear transition-metal cluster anions are also known. Each of these areas will be discussed briefly in this contribution. PMID:21743925
Composite materials of synthetics (based on monomers, oligomers and thermoplastics) and of natural polymers (wood and other fibrous cellulosics) prepared by radiation processing, offer valuable structural materials with enhanced coupling forces between the components. The applied polymer chemistry of such composites shows several common features with that of radiation grafting. E.g. the polymerization rate of oligomer-monomer mixtures in wood remains in most cases proportional to the square-root of the initiating dose-rate, just as in the simultaneous grafting, demonstrating that the chain termination kinetics remain regularly bimolecular in the corresponding dose-rate ranges. In the processing experiences of such composites, low dose requirement, easy process-control, and good technical feasibility have been found for composites of wood with oligomer-monomer mixtures, for coconut fibres with unsaturated polyesters and for pretreated wood fibre with polypropylene.
Composite materials of synthetics (based on monomers, oligomers and thermoplastics) and of natural polymers (wood and other fibrous cellulosics) prepared by radiation processing, offer valuable structural materials with enhanced coupling forces between the components. The applied polymer chemistry of such composites shows several common features with that of radiation grafting, e.g. the polymerization rate of oligomer-monomer mixtures in wood remains in most cases proportional to the square-root of the initiating dose-rate, just as in the simultaneous grafting, demonstrating that the chain termination kinetics remain regularly bimolecular in the corresponding dose-rate ranges. In the processing experiences of such composites, low dose requirement, easy process-control, and good technical feasibility have been found for composites of wood with oligomer-monomer mixtures, for coconut fibres with unsaturated polyesters and for pretreated wood fibre with polypropylene. ...
This paper presents the regulatory experience gained from Wolsong Units 2,3 and 4 - Special Safety System Instrumentation Uncertainty for Trip Setpoint and Allowable Values. The equipment diversity method for the defense against common mode failure was applied to the transmitters of shutdown system number 2. However the Units experienced an unexpected drift problem with which the performance did not meet the Technical Specification (Tech Spec) Surveillance Requirements (SR). Discussed are the background, status and corrective actions, regulatory positions and issues to be solved for the drift problem. It was an instrument uncertainty methodology that the designer of safety system should have shown when the drift problem occurred. For deeper understanding of the problem, we present the background of Tech Spec SR for setpoints in Korean PWR and in CANDU reactors. The Setpoint Verification Test(SVT) and Calibration Test(CT) shall be achieved by recording sufficient ...
An experiment was performed with a mock-up of the core of the Fast Flux Test Facility (FFTF) reactor to evaluate three reactivity measurement methods for application to liquid-metal fast breeder reactors (LMFBR): modified source multiplication measurements with the low-level flux monitor for refueling (35 dollars subcritical) of FFTF, noise analysis to 35 dollars subcritical, and inverse kinetics rod drop to 12 dollars subcritical. To investigate the spatial dependence of these measurement methods and to resolve discrepancies previously reported, detectors were placed in the core, reflector, and radial shield, and experimental data were collected with the reactivity at near delayed criticality to 35 dollars subcritical. Conclusions from this experiment are the following. Low-level flux monitors in the shield of the FFTF will be adequate for reactivity surveillance during refueling, using the modified source multiplication method calibrated near critical by an ...
In order to watch the environment of the construction site of dismantling of the former pipe of releases in sea of Cogema-La Hague, the special and permanent commission of Information near the establishment Cogema of La Hague (C.S.P.I.) asked the association for the radiation monitoring in the West (A.C.R.O.) to realize a specific campaign of measures, on the basis of a protocol accepted by the C.S.P.I.. During the three years of the building work, two significant increases of the concentration in {sup 137}Cs in the marine flora with at most, 9.3 Bq/kg dry, are noticed so be it ten times the concentration that could be measured before the building work begins. We note a net improvement of the situation after the works. The {sup 137}Cs tends finally to disappear. For the sedimentary masses and the sands of beaches, it is outlined no increase of the contamination in {sup 137}Cs (during the works and in posteriori) which translates in a irrefutable way contributions of the construction ...
There have been many questions about the costs of providing medical services. These questions have resulted in the development of Resource-Based Relative Values Scale (RBRVS) at the national level. Policymakers view RBRVS as a potential tool to pay physicians. The questions, about the cost of operations of HSE-2 at Los Alamos National Laboratory, revolve around doing routine occupation health physicals for the Laboratory. Generally, these questions are concerned about why the costs appear to be high relative to what private physician suggests the costs should be. There is also an interest in trying to find methods to reduce these costs if possible. Many of the tools developed to help in construction estimating can be applied to estimating medical costs. With the need to perform many thousands of physicals each year the saving of even a few dollars for each exam can quickly add up to a large saving. There are a number of different types of physicals and different levels; based on age, ...
To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the lowest doses to the ...
Purpose: To examine the role of brachytherapy in the treatment of cholangiocarcinomas in a relatively large group of patients. Methods and Materials: Using the Surveillance, Epidemiology and End Results database, a total of 193 patients with cholangiocarcinoma treated with brachytherapy were identified for the period 1988-2003. The primary analysis compared patients treated with brachytherapy (with or without external-beam radiation) with those who did not receive radiation. To try to account for confounding variables, propensity score and sensitivity analyses were used. Results: There was a significant difference between patients who received radiation (n = 193) and those who did not (n = 6859) with regard to surgery (p < 0.0001), race (p < 0.0001), stage (p < 0.0001), and year of diagnosis (p <0.0001). Median survival for patients treated with brachytherapy was 11 months (95% confidence interval [CI] 9-13 months), compared with 4 months for patients ...
Cooling water is sprayed on the outer surface of an upper portion of a container, and a pool is formed by the cooling water flowing down while cooling the container. Further, the cooling water stored in the cooling water pool is recycled by a pump for spraying the cooling water on the outer surface of the upper portion of the container. Sufficient amount of cooling water is supplied for spraying the cooling water to the outer surface of the upper portion of the container so that the outer surface of the container is free from drying and a liquid membrane is formed on the entire surface. The amount of the cooling water is made greater than that of the cooling water evaporated when the entire amount of the heat generate in the reactor core of the reactor is transferred to the cooling ...
Water-resources data for the 1993 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; and stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 3 contains records for water discharge at 134 gaging stations; stage only at 1 gaging stations; stage and contents at 13 lakes and reservoirs; water quality at 81 gaging stations; and data for 30 partial-record and 4 flood-hydrograph partial-record stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations; crest-stage and flood-hydrograph partial-record stations, reconnaissance ...
DescriptionThis cross-disciplinary project will combine chemical, ecological and modelling techniques to determine whether cabbages grown under an organic regime differ in terms of pest dynamics and plant chemistry. There is increasing pressure to de-intensify agricultural practice and organic approaches are becoming more popular and widely adopted. However, there are very few, if any, detailed scientific investigations into the claims made about improved pest control, reduced environmental impact and be [continued...
This extended article describes Sasol, the synthetic fuel producing plant in South Africa. It produces other fuels in addition to synfuel, from local coal. A very thorough review covering all aspects of the plant is given. These include: economic; chemical and environmental. The chemistry of the processes involved, the Fischer-Tropsch synthesis and the Lurgi process are described in some detail. Consideration is also given to the establishment of new plants, research and development projects, marketing and available coal resources.
Aimed at post-graduate and post-doctoral researchers in geochemistry, this book reflects the rapid changes in the applications of radioactive and stable isotope analysis to a range of geological and geochemical problems. Isotropic chemistry and methods used in mass spectroscopy are discussed initially. The second section deals with radiometric dating methods. The role of isotopes in climate and environmental research is also explored. The book closes with a section on extra-terrestrial matter, geothermometry and the isotopic geochemistry of the Earth`s lithosphere. (UK).
Research performed at LAMPF during 1985 is reported in the areas of: nuclear and particle physics; atomic and molecular physics; materials science; radiation-effects studies; biomedical research and instrumentation; nuclear chemistry; radioisotope production; and physics theory. Also reported are the status of LAMPF-II, facility development work, and accelerator operations. (LEW)
This paper advances hypotheses on the chemistry of the interaction of thorium and yttrium with organic-inorganic salts of molybdenum polyacids. On the basis of an analysis of the data of an adsorption experiment and the quantitative relationships that follow from the law of mass action, it is shown that thorium is absorbed by the solid phase by coprecipitation with the participation of complex formation, while the coprecipitation of yttrium with salts of polyacids is due to a reaction of ion exchange chemisorption.
With collaboration between chemistry, X-ray crystallography, and molecular modeling, we designed and synthesized a series of novel piperazine sulfonamide BACE1 inhibitors. Iterative exploration of the non-prime side and S2prime sub-pocket of the enzyme culminated in identification of an analog that potently lowers peripheral Ab40 in transgenic mice with a single subcutaneous dose.
During the past 3 years, progress was made in elucidating the excited state structures of Pt(diimine)(dithiolate) complexes, while more recent efforts focused on the photochemistry of these complexes and electronic structure of other dithiolate systems. A carbonyl-Ir-maleonitrile dithiolate complex is also studied.
Science and technology are at the heart of everything we do at the National Renewable Energy Laboratory, as we pursue innovative, robust, and sustainable ways to produce energy--and as we seek to understand and illuminate the physics, chemistry, biology, and engineering behind alternative energy technologies. This year's Research Review highlights the Lab's work in the areas of alternatives fuels and vehicles, high-performing commercial buildings, and high-efficiency inverted, semi-mismatched solar cells.
This comprehensive, critical review summarizes the use of nanoparticles in enhanced and amplified chemiluminescence detection, illustrated by different reaction strategies, electrogenerated chemiluminescence sensors, immunoassay or hybridization labels and electrogenerated chemiluminescence immunoassay or hybridization sensors. We discuss the analytical applications on the basis of validity, range and sensitivity, and draw some useful conclusions about the most sensitive approach in each type of application.
Microwaves improve the rate of many chemical reactions either interacting with the solvent, when the reaction is carried out in solution, or with the surface of a solid substrate where a suitable reagent is dispersed (dry chemistry). A few examples of chemical reactions positively affected by microwaves are described: particularly interesting are those concerning polymers and radio-pharmaceuticals.
Focused ion beam (FIB) systems prove to be useful precision micromachining tools for a wide variety of applications. This micromachining technique includes scanning ion microscopy (SIM), micromachining by physical sputtering, and the ion-beam induced surface chemistry for etching and deposition. This technique is applied to image and modify IC's, to micromechanical applications, to modify the tip shape of tungsten emitters, and to prepare cross sections of selected regions for inspection in a transmission electron microscope (TEM). (orig.)
This report summarizes the activities and major accomplishments for the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2002. Topics covered include computational dosimetry and treatment planning software development, medical neutron source development and characterization, and boron analytical chemistry.
This report summarizes the activities and major accomplishments for the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2002. Topics covered include computational dosimetry and treatment planning software development, medical neutron source development and characterization, and boron analytical chemistry.
The mid-range industrial market currently consumes 4.2 million metric tons of hydrogen per year and has an annual growth rate of 15% industries in this range require between 100 and 1000 kilograms of hydrogen per day and comprise a wide range of operations such as food hydrogenation, electronic chip fabrication, metals processing and nuclear reactor chemistry modulation.
...Modern Languages Music Philosophy Faculty of Medicine Faculty of Medicine page Academic unit: Medicine Faculty of Natural and Environmental Sciences Faculty of Natural and Environmental Sciences page Academic units: Biological Sciences Chemistry National Oceanography Centre, Southampton Ocean and Earth Science Faculty of Physical and Applied Sciences Faculty of Physical and Applied Sciences page Academic units: Electronics and Computer Science Optoelectronics Research Centre Physics and Astronomy Faculty of Social and Human Sciences ...
This article examines the impact of mist-eliminator (ME) design and reliability on the performance of flue gas desulfurization (FGD) processes. ME failures are the second most common cause of FGD system outages. ME design also affects the chemistry of the FGD processes. The author considers the ME the linchpin of the whole FGD process system.
Unsymmetric diaryl alkynes were synthesized from the palladium-catalyzed decarboxylative coupling of aryl halides and propiolic acid using a continuous flow reaction system. This flow chemistry system continuously gave the desired products in moderate to good yields, and produced less byproduct than was formed in the batch reaction.
Interaction of drilling fluids with a geothermal reservoir formation can result in significant permeability impairment and therefore reduced well productivity. This interaction is studied under simulated in situ geothermal conditions of overburden stress, pore fluid pressure, temperature, and pore fluid chemistry. Permeability impairment of an East Mesa KGRA reservoir material is evaluated as a function of stagnation time, drilling fluid, and temperature. Results indicate that all of these parameters contribute significantly to the magnitude and the reversibility of the impairment.
Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-fold: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.
Consol R D is conducting a three-year program to characterize process and product streams from direct coal liquefaction process development projects. The program objectives are two-field: (1) to obtain and provide appropriate samples of coal liquids for the evaluation of analytical methodology, and (2) to support ongoing DOE-sponsored coal liquefaction process development efforts. The two broad objectives have considerable overlap and together serve to provide a bridge between process development and analytical chemistry.
Most chemical reactions in industry and biology are catalytic and play a role at some stage of the processing of about 80% of the goods manufactured in the U.S., yet catalysis is a neglected subject in chemical education. This book integrates the fragmentary treatment accorded the topic until now. It covers, in a unified way, catalysis in solutions, by enzymes, in synthetic polymers within the molecular scale cages of zeolites and other molecular sieves, and on surfaces of inorganic solids. The central ideas are chemical; and principles are illustrated by emphasizing industrial reactions and catalysts.
Three independent studies have been conducted for assessing the impact of rocket launches on the earth`s environment. These studies have addressed issues of acid rain in the troposphere, ozone depletion in the stratosphere, toxicity of chemical rocket exhaust products, and the potential impact on global warming from carbon dioxide emissions from rocket launches. Local, regional, and global impact assessments were examined and compared with both natural sources and anthropogenic sources of known atmospheric pollutants with the following conclusions: (1) Neither solid nor liquid rocket launches have a significant impact on the earth`s global environment, and there is no real significant difference between the two. (2) Regional and local atmospheric impacts are more significant than global impacts, but quickly return to normal background conditions within a few hours after launch. And (3) vastly increased space launch activities equivalent to 50 U.S. Space Shuttles or 50 Russian Energia ...
The object of this paper is to show how the profile of metal concentration in the soil near bone from archaeological sites can be used, along with the appropriate mathematical model, to extract transport parameters. These parameters can then be used to predict long-term migration rates of chemical species associated with the burial of hazardous wastes in similar environmental settings.
The DED, Department of the Wastes Studies, part of the Direction of the Nuclear Energy of the CEA, regroups knowledge in the domain of the chemistry, the biochemistry, the process measures and simulation engineering applied to the radioactive wastes management. This annual report presents for the year 2001 the missions, the organization, the scientific collaborations, the research programs and the publications of the Department. (A.L.B.)
British Nuclear Fuels (BNFL) is currently operating its third generation of nuclear plant for the management of irradiated nuclear fuel. Development for the fourth generation plant must meet requirements for processing higher burn-up fuel with lower unit costs, lower environmental impact, better process control, and more flexible control of actinides. .
Programs in coal research by the Pittsburgh Energy Technology Center are discussed. Topics include: Coal Science and Chemistry, Coal Liquefaction, Alternative Fuels, Coal Preparation, Combustion, MHD Program, Flue Gas Cleanup, Environmental Coordination, and Technology Transfer. (CBS)
...Species - see CITES Trade of Dangerous Chemicals Transport and Environment U Urban Environment Use of natural resources V Volatile Organic Compounds W Waste Landfills Waste electrical and electronic equipment - see WEEE Waste incineration Waste legislation - reporting Waste management planning Waste oils Waste shipments Waste water - see Urban waste waterWater Bathing Water Drinking water Floods Marine environment Urban waste waterWater Framework Directive WEEE - Waste Electric and Electronic Equipment Wildlife ...
This report is a summary of the contribution of nitrogen and phosphorus in the eutrophication process of inland and coastal waters. Special attention was paid to the mechanisms of these nutrients in regulating biological processes and to the methods available in estimating their effects in the eutrophication of water bodies. The report includes five chapters which are entitled: Introduction, which is a general background to the subject with special attention to the requirements of the Finnish Water Act. Phosphorus and nitrogen as factors regulating biological processes. The topics included are: definition of eutrophication, forms of phosphorus and nitrogen and their sources to inland and coastal waters, effects of these nutrients as growth factors of phytoplankton and macrophytes and consequences of eutrophication. Estimation of the effects of phosphorus and nitrogen. The topics discussed from the point ...
This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate the effect of ionic ...
The study investigates the possibility of enhancing crop water productivity in the parts of Northwest India where groundwater quality is marginal and canal water supply is severely scarce. Soil, Water, Atmosphere and Plant (SWAP) model was calibrated and validated in three farmers' fields with varying canal water availability and groundwater quality in the Kaithal Irrigation Circle of the Bhakra Canal system, Haryana. On the basis of predicted and observed soil water content, pressure heads, salt concentration at 2 week intervals and crop yields, the model was found suitable for use in the region. A few nomographs were prepared to provide a graphical method to predict the effect of different combinations of water quality and depth of water application on crop yield and soil salinity and to...
Using the Laser-Fluorescence technique, an investigation was made, adopting the standard mix method, on trace uranium concentrations in hot spring water and geothermal water from Lishan region, and in tap water from some major cities in Shanxi province. Totally 40 samples from 27 sites were investigated. Measurement showed that the tap water contains around 10"-"6 g/L of uranium, whose concentrations in both hot spring water and geothermal water are 10"-"5 g/L. Most of samples are at normal radioactive background level, some higher contents were determined in a few samples
In equipment industries, the equipments handling industrial water and pure water are numerous. In power generation including nuclear power generation, water serves as a working medium. Review is made on the experiences in the corrosion of iron and nickel base alloys in high temperature, high pressure water and the results of researches derived from them. Under high temperature and high pressure, carbon steel, low alloy steel, stainless steel and high nickel alloy cause corrosion even in pure water. But in the case of serious corrosion, chlorine, oxygen, alkali and others in water take part. The following matters are described: corrosion by steam; stress corrosion cracking in pure water; corrosion by impurities in high temperature, high pressure pure water, i.e. chlorine ions, dissolved oxygen, and alkali; corrosion under ...
...AquaMagna Water Conditioner and Descaler OCETA Environmental Technology & Business Profiles AQUAMAGNA WATER CONDITIONER AND DESCALER CAT. #03-018 CONTACT: Magna-Tek ...removal high-strength ceramic magnet no energy input The AquaMagna Water Conditioner and Descaler is a non-chemical method of water treatment. The technology uses ... Figure 1: The AquaMagna Water Conditioner and Descaler PROCESS/ PRODUCT APPLICATION: hard water domestic water process water reverse osmosis heat exchangers cooling ... For once-through or recirculating heating or cooling equipment, the AquaMagna descaler improves thermal efficiencies and reduces downtime. Figure 2 illustrates a cross-section ...
This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users. (author)
...Tota-MaharajE-Mail: Interests: water and wastewater treatment, environmental engineering and sustainable systems; sustainable water management; sustainable urban drainage systems (SUDS); combined renewable energy applications with reverse osmosis desalination; microbial fuel cells for bioenergy production and treatment of urban wastewater; solar photocatalytic treatment and disinfection of water/wastewater Dr. Simon Toze CSIRO Land and Water, Queensland Bioscience Precinct - St Lucia, 306 Carmody Road, St Lucia QLD 4067,...
Indicators of source water use in different economic branches, water consumption in recycling and recycling-successive water supply in 1980?2006 are analyzed. Trends were identified in variations in specific water consumption in industry, agriculture, and municipal economy. Territorial differentiation of wetness indicators of regional product over federal districts and constituent territories of the RF is shown. Wetness values of gross domestic product in different economies are compared.
number Fax (501) 228-3600 (501) 228-3601 Surface Water Data Information Requests Bill Baldwin (501) 228-3602 Surface Water General Information Jaysson Funkhouser (501) 228-3663...
Background Microbial water-quality indicators, in high concentrations in sewage, are used to determine whether water is safe for recreational purposes. Recently, the use of these indicators...Full Text Available
In order to reduce the air concentration of (sup 3)H in the reactor buiIding of Wolsung Heavy Water Reactor, a computer code for estimation of adsorption behavior was programmed based on an equation derived for analysis of water vapor adsorption, and a ba...
Before the implementation Water Framework directive, it was usual to forget that a good environment protection of the receiving waters needs a correct and coordinated operation of the subsystems of the water cycle, specially sewerage system, WWTP and receiving waters. This explains that most of the countries have focused their efforts in the treatment of dry weather flows forgetting the management of wet weather flows. Actually the idea that a sewerage system or a WWTP can not be planned or managed independently without considering the effects on the receiving waters is commonly accepted because not only each one of these systems must work correctly but also it is required a minimum impact in the receiving waters of the sewerage and WWTP overflows in dry and wet weather. All these links will affect the management strategy of the sewerage system (storm ...
The effect of the water-chemical regime (WCR) on damage sustained by heating surfaces of steam generators at NPP is analyzed. It is indicated that phosphate treatment with minimal excesses of phosphates in the steamgenerator water is the most optimal method of managing the WCR regime of horizontal steam generators.
The effect of water stress on patterns of nitrate reductase activity in the leaves and nodules and on nitrogen fixation were investigated in Medicago sativa L. plants watered 1 week...Full Text Available
The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source–detector...Full Text Available
A model was developed to compute concentration of impurities in the WWER 440 steam generator (SG) secondary water along the tube bundle. Calculated values were verified by concentration values obtained from secondary water sample chemical analysis. (orig.). 2 refs.
A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential....Full Text Available
By the time of primary 21st century, water hyacinth had become a serious environmental problem in China. Water hyacinth contributes to the major part of ecological hazards from the invasion of foreign...Full Text Available
Background and AimsXylem vessels containing gases (embolized) must be refilled with water if they are to resume transport of water through the plant, so refilling is of great importance...Full Text Available
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 ...
Object: To smoothly control automatic water supply for realizing stable operation of a nuclear reactor by providing a flow rate limiting signal selection circuit and a preferential circuit in a water supply control device for a nuclear reactor wherein the speed of a recirculation pump may be changed in two-steps. Structure: Opening angle signals for a water supply regulating valve are controlled by a nuclear reactor water level signal, a vapor flow rate signal and a supplied water flow rate signal through an adder and an adjuster in response to a predetermined water level setting signal. When the water in the reactor is maintained at a predetermined level, a selection circuit receives a water pump condition signal for selecting one of the signals from a supplied water rate limiting signal generator ...
Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study...Full Text Available
THMs are disinfection by-products (DBPs) generated during water chlorination. Concentration of individual and total THMs, depends on treatment process and THMs precursors level. ATLL water utility has two DWTP (Llobregar and Ter) that produce and supply drinking water to Barcelona and regional area. This work studies the levels of THMs along the ATLL distribution system (450 km). Although, no differences were observed along water pipes system, changes of water resource and mix procedures were related. (Author) 12 refs.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
The transport of liquid water and gaseous reactants through a gas diffusion layer (GDL) is one of the most important water management issues in a proton exchange membrane fuel cell (PEMFC). In this work, the liquid water breakthrough dynamics, characterized by the capillary pressure and water saturation, across GDLs with and without a microporous layer (MPL) are studied in an ex-situ setup which closely simulates a real fuel cell configuration and operating conditions. The results reveal that recurrent breakthroughs are observed for all of the GDL samples tested, indicating the presence of an intermittent water drainage mechanism in the GDL. This is accounted for by the breakdown and redevelopment of the continuous water paths during water drainage as demonstrated by Haines jumps. For GDL ...
Water is one of our most precious resources. However, for many in the United States, having fresh, safe drinking water is taken for granted, and due to this perceived lack of relevance, students may not fully appreciate the luxury of having safe running water--in the home. One approach to resolving water-quality issues in the United States may reside in providing education that presents accurate information in a meaningful way. Accordingly, this article describes a unit designed to emphasize the importance of water-quality testing and purification and to introduce students to local water-quality issues. The engineering-based module of this eighth-grade science activity is particularly important due to the design-build-test component. (Contains 5 figures.)
Ground water is treated in the Czech Republic so that small water tanks are built above each water source to serve the primary ground water treatment; water so pretreated is then concentrated in large basins for subsequent treatment. Some water tanks where the first contact of the ground water with air takes place were selected as sites predisposed to radon accumulation. The examination was carried out near the town of Jihlava, where the bedrock contains slightly elevated radium concentrations. The average radon concentrations lay within the region of 2-4 kBq/m"3; the instantaneous values, however, exhibited appreciable periodical variations during the day. The relatively high radon concentrations will not pose a marked hazard for the personnel because the employees only reside at the sites in question for 10 to 15 minutes within 2 days, not ...
A single cylinder diesel engine study of water-in-diesel emulsions was conducted to investigate the effect of water emulsification on the engine performance and gases exhaust temperature. Emulsified Diesel fuels of 0, 5, 10, 15 and 20 water/diesel ratios by volume were used in a single cylinder, direct injection diesel engine, operating at 1200-3300 rpm. The results indicate that the addition of water in the form of emulsion improves combustion efficiency. The engine torque, power and brake thermal efficiency increase as the water percentage in the emulsion increases. The average increase in the brake thermal efficiency for 20% water emulsion is approximately 3.5% over the use of diesel for the engine speed range studied. The proper brake specific fuel consumption and gases exhaust temperature decrease as the percentage of water in the ...
... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... ...
This site explains how temperature, pressure, and salinity work together to determine the density of ocean water. The three density layers of the ocean are described by means of text description and a graphic illustration.
Using air as a carrier gas is common in humidification?dehumidification desalination processes. A computer program was written using mass and energy balances for modeling the process behavior. The parameters considered in this work were inlet air and fresh water recycle temperatures, inlet air flow rate, saline water and fresh water recycle flow rates, and saline water to air flow ratio. Results of simulation showed that increasing inlet air and fresh water recycle flow rate increases fresh water production. It was also found that heating the inlet air to humidification column or cooling the inlet water to dehumidification column increases the production rate but increasing water to air flow ratio in a humidifier leads to a lower production rate. The predicted effects of the parameters on ...
The largest outbreak of cryptosporidiosis reported in the United Kingdom, involving 575 confirmed cases (of which 474 met an agreed case definition), occurred in the county of Devon during August and September of 1995. The descriptive epidemiology supports the hypothesis that the outbreak was associated with the consumption of cold tap water in the area served by a particular water treatment works. Cryptosporidium oocysts were detected in treated water samples at the time of the outbreak. Although the epidemiological analysis provided strong circumstantial evidence of a waterborne outbreak, the data were not recorded in a manner that made them admissible in criminal proceedings taken by the Drinking Water Inspectorate against the water company involved. The need to carry out an analytical study in conjunction with the identification and characterisation of the pathogen in the ...
ObjectiveTo evaluate the effect of moderate aerobic physical activity in water on fetal cardiotocography patterns in sedentary pregnant women.MethodIn...Full Text Available
The very low-pressure expansion tank of the title invention is connected to the water in the central heating installation via a connecting pipe with a pump and valves on one side, and on the other side the tank is connected via a connecting pipe with valve to the tap water mains, so that the supply of water can be regulated automatically. Within the expansion tank contact with the outside air is not possible because of an air/water separating floater. By means of recording and control (also remote) of the contents of the expansion tank, the installation pressure and the quantity of supplied water from the expansion tank and the tap water mains, failures and water damage are prevented. 4 figs.
An environmental study was done to examine the prevalence of Vibrio mimicus in some aquatic environments of Dhaka, Bangladesh, and of Okayama, Japan. Water samples from Dhaka environments and water...Full Text Available
density is slightly higher, its electrical conductivity is much higher, and it is slightly ... Sea water has characteristic properties (e.g. density) that are independent of ...
In the Mediterranean arc, vines for wine production are mainly grown without the support of irrigation. Under such conditions, site variables affecting the extent and seasonal timing of water deficits are the dominant environmental constraints for grape production. Moreover, water availability and vine water status are the factors most comprehensively determining fruit composition and, thus, wine quality. Therefore, monitoring the extent of water stress in vines might be a valuable tool for the optimisation of grape yield and quality. The objective of this study was to evaluate the feasibility of using the reflectance based Water Index (WI) to estimate vine water status at the leaf and canopy levels. The study was conducted on Vitis vinifera cv. Chardonnay potted plants submitted to contra...
Halothane, chloroform, and carbon tetrachloride, in the vapor and liquid phases, stimulate the water receptor of the blowfly Phormia regina. There are three successive phases of response to long-lasting...Full Text Available