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Sample records for strontium-90 equilibrium parameters

  1. The strontium-90 equilibrium parameters in Saclay soil; Les parametres d'equilibre du strontium 90 dans le sol de Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P; Gailledreau, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The equilibrium parameters of {sup 90}Sr in the presence of the following elements: Ca, Na, K, NH{sub 4} are measured in the soil at Saclay for each of the pairs Sr-Ca, Sr-Na, Sr-K, Sr-NH{sub 4}. The adsorption mechanism for Sr is studied in comparison with a synthetic resin which is a pure ion-exchanger. A preliminary study of a three component system; one being a tracer, is outlined. (author) [French] Les parametres d'equilibre du {sup 90}Sr en presence des elements suivants: Ca, Na, K, NH{sub 4} sont mesures sur le sol de Saclay pour chacun des couples Sr-Ca, Sr-Na, Sr-K, Sr-NH{sub 4}. Le mecanisme d'adsorption du Sr est etudie par comparaison avec une resine synthetique qui est un echangeur d'ions pur. Une etude preliminaire d'un systeme a trois composants, dont l'un est un traceur, est exposee. (auteur)

  2. Strontium-90 - ED 4309

    International Nuclear Information System (INIS)

    Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Le Guen, B.; Pihet, P.; Rannou, A.; Vidal, E.

    2012-12-01

    This sheet presents the characteristics of strontium-90, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of wastes and effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the transport of strontium-90, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

  3. Strontium 90 fallout prediction

    International Nuclear Information System (INIS)

    Sarmiento, J.L.; Gwinn, E.

    1986-01-01

    An empirical formula is developed for predicting monthly sea level strontium 90 fallout (F) in the northern hemisphere as a function of time (t), precipitation rate (P), latitude (phi), longitude (lambda), and the sea level concentration of stronium 90 in air (C): F(lambda, phi, t) = C(t, phi)[v /sub d/(phi) + v/sub w/(lambda, phi, t)], where v/sub w/(lambda, phi, t) = a(phi)[P(lambda, phi, t)/P/sub o/]/sup b//sup (//sup phi//sup )/ is the wet removal, v/sub d/(phi) is the dry removal and P 0 is 1 cm/month. The constants v/sub d/, a, and b are determined as functions of latitude by fitting land based observations. The concentration of 90 Sr in air is calculated as a function of the deseasonalized concentration at a reference latitude (C-bar/sub r//sub e//sub f/), the ratio of the observations at the latitude of interest to the reference latitude (R), and a function representing the seasonal trend in the air concentration (1 + g): C-bar(t, phi) = C/sub r//sub e//sub f/(t)R(phi)[1 + g(m, phi)]; m is the month. Zonal trends in C are shown to be relatively small. This formula can be used in conjuction with precipitation observations and/or estimates to predict fallout in the northern hemisphere for any month in the years 1954 to 1974. Error estimates are given; they do not include uncertainty due to errors in precipitation data

  4. Strontium-90 fluoride data sheet

    Energy Technology Data Exchange (ETDEWEB)

    Fullam, H.T.

    1981-06-01

    This report is a compilation of available data and appropriate literature references on the properties of strontium-90 fluoride and nonradioactive strontium fluoride. The objective of the document is to compile in a single source pertinent data to assist potential users in the development, licensing, and use of /sup 90/SrF/sub 2/-fueled radioisotope heat sources for terrestrial power conversion and thermal applications. The report is an update of the Strontium-90 Fluoride Data Sheet (BNWL-2284) originally issued in April 1977.

  5. Strontium-90 measurements in Switzerland

    International Nuclear Information System (INIS)

    Friedli, C.; Geering, J.J.; Lerch, P.

    1988-01-01

    Strontium-90 contamination in Switzerland has been measured since the sixties. The determination of 90 Sr in human vertebrae, milk-teeth, milk and wine have shown a maximum activity between 1964 and 1966. Since 1976, the survey has been extended to the food chain. After the Chernobyl accident, the measurements indicated a significative 90 Sr contamination in the Tessin and the north-east of Switzerland. The partition of 90 Sr in wheat has been determined and transfer factors are given for the milk - cheese - whey chain

  6. Strontium 90 in Swedish dairy milk 1978

    International Nuclear Information System (INIS)

    Gillberg-Wickman, M.; Oestergren, I.

    1980-01-01

    The contamination of strontium-90 in Swedish milk during 1978 is practically the same as in 1977. The country-wide mean ratio of strontium-90 to calcium in milk is 0.12 Bq 90 Sr(gCa) -1 , based on monthly determinations of samples obtained from 8 dairy plants situated throughout the country. (author)

  7. Strontium-90 migration in Hanford sediments, USA

    International Nuclear Information System (INIS)

    Steefel, C.I.; Yang, L.; Carroll, S.A.; Roberts, S.; Zachara, J.M.; Yabusaki, S.B.

    2005-01-01

    Full text of publication follows: Strontium-90 is an important risk-driving contaminant at the Hanford site in eastern Washington, USA. Disposal operations at the Hanford 100-N area released millions of liters of reactor cooling water containing high concentrations of strontium-90 into the vadose zone immediately adjacent to the Columbia River. The effectiveness of pump-and-treat methods for remediation have been questioned, largely because the strontium is strongly sorbed on subsurface sediments via ion exchange reactions and co-precipitation in carbonates. In addition, groundwater monitoring wells show a fluctuating seasonal behavior in which high strontium-90 concentrations correlate with high Columbia River stage, even while average concentrations remain approximately constant. A series of fully saturated reactive transport column experiments have been conducted to investigate the important controls on strontium migration in Hanford groundwater [1]. The experiments were designed to investigate the multicomponent cation exchange behavior of strontium in competition with the cations Na + , Ca +2 , and Mg +2 , the concentration of which differs between river water and groundwater. Reactive transport modeling of the experiments indicates that the Sr +2 selectivity coefficient becomes larger with increasing NaNO 3 concentration, a behavior also shown by the divalent cations Ca +2 and Mg +2 . A new set of column experiments investigates the effect of wetting and drying cycles on strontium- 90 sorption and migration by considering episodic flow in Hanford sediments. In addition, the effect of fluctuating aquifer chemistry as a result of changes in the Columbia River stage on Sr +2 sorption is addressed. Modeling of multicomponent reactive transport under variably saturated conditions is used to interpret the results of the episodic flow/chemistry experiments. [1] Experimental and modeling studies of the migration behavior of strontium in Hanford sediments, USA. C

  8. Ecological Dose Modeling of Aquatic and Riparian Receptors to Strontium-90 with an Emphasis on Radiosensitive Organs

    Energy Technology Data Exchange (ETDEWEB)

    Poston, Ted M.; Traub, Richard J.; Antonio, Ernest J.

    2011-07-20

    The 100-NR-2 site is the location of elevated releases of strontium-90 to the Columbia River via contaminated groundwater. The resulting dose to aquatic and riparian receptors was evaluated in 2005 (DOE 2009) and compared to U.S. Department of Energy (DOE) dose guidance values. We have conducted additional dose assessments for a broader spectrum of aquatic and riparian organisms using RESRAD Biota and specific exposure scenarios. Because strontium-90 accumulates in bone, we have also modeled the dose to the anterior kidney, a blood-forming and immune system organ that lies close to the spinal column of fish. The resulting dose is primarily attributable to the yttrium-90 progeny of strontium-90 and very little of the dose is associated with the beta emission from strontium-90. All dose modeling results were calculated with an assumption of secular equilibrium between strontium-90 and yttrum-90.

  9. Strontium-90 and promethium-147 recovery

    International Nuclear Information System (INIS)

    Hoisington, J.E.; McDonell, W.R.

    1982-01-01

    Strontium-90 and promethium-147 are fission product radionuclides with potential for use as heat source materials in high reliability, non-interruptible power supplies. Interest has recently been expressed in their utilization for Department of Defense (DOD) applications. This memorandum summarizes the current inventories, the annual production rates, and the possible recovery of Sr-90 and Pm-147 from nuclear materials production operations at Hanford and Savannah River. Recovery of these isotopes from LWR spend fuel utilizing the Barnwell Nuclear Fuels Plant (BNFP) is also considered. Unit recovery costs at each site are provided

  10. Measurement of strontium 90 in the rain fall-out

    International Nuclear Information System (INIS)

    Suratman; Soedyartomo; Suhartono.

    1976-01-01

    The procedure of radioactivity measurement of strontium 90 in the rain fallout as well as the measurement of the fallout gross beta activity have been studied. In the preliminary study strontium 90 is separated from other cations especially fission products by fuming nitric acid, and radioactivity measurement is carried out in the form of strontium oxalate. Data of radioactivity measurement of strontium 90 and the gross beta activity in the fallout are given. (author)

  11. Strontium-90 and cesium-137 in powdered milk

    International Nuclear Information System (INIS)

    1977-01-01

    Japan Chemical Analysis Center has analysed the strontium-90 and cesium-137 content in powdered milk. The samples were purchased on the open market in Tokyo from the powdered milk producers. The analysis of Strontium-90 and Cesium-137 content was carried out using the method recommended by Science and Technology Agency. (author)

  12. Strontium 90 in silts of the Dnieper cascade water reservoirs

    International Nuclear Information System (INIS)

    Romanenko, V.D.; Kuz'menko, M.I.; Matvienko, L.P.; Klenus, V.G.; Nasvit, O.I.

    1989-01-01

    The change of strontium-90 content in water and silts of the Dnieper cascade water reservoirs was analyzed. It was shown, that decrease of strontium-90 content in water in time connected basically with ion exchange adsorption of strontium-90 by residues. A high sorption ability of residues made it possible for radioisotopes to reduce sharply their concentration along depth of soils. The highest concentration of radioisotopes was in the upper layers, enriched by silt. It was ascertained, that strontium-90 migration along depth of residues took place rapidly in the Kiev's water reservoir. Down the cascade strontium-90 content reduced in lower layers of residues as well as in upper layers. 4 tabs

  13. Migration of strontium-90 from a strontium-90 fluoride deep ocean source

    International Nuclear Information System (INIS)

    Yabusaki, S.

    1981-06-01

    A hypothetical rupture of a heat source capsule on the ocean floor is analyzed for strontium-90 migration and attenuation. The evolution of the three-dimensional contaminant plume is simulated by a modified version of the Okubo-Pritchard radially symmetrical, diffusion velocity dispersion model. Results from this study indicate that released solutes are confined vertically to a layer near the level of introduction. Along the plume centerline, however, water quality is affected for considerably distances downstream from the source, with the maximum effect occurring after one year

  14. Strontium-90 and cesium-137 in tea (Japanese tea)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in tea (Japanese tea) were determined. Five hundred grams of manufactured green tea was collected from six sampling locations in Japan. The results are shown in a table. (Namekawa, K.)

  15. Strontium-90 Error Discovered in Subcontract Laboratory Spreadsheet. Topical Report

    International Nuclear Information System (INIS)

    Brown, D.D.; Nagel, A.S.

    1999-07-01

    West Valley Demonstration Project health physicists and environment scientists discovered a series of errors in a subcontractor's spreadsheet being used to reduce data as part of their strontium-90 analytical process

  16. Strontium-90 at the Hanford Site and its ecological implications

    International Nuclear Information System (INIS)

    RE Peterson; TM Poston

    2000-01-01

    Strontium-90, a radioactive contaminant from historical operations at the U.S. Department of Energy (DOE) Hanford Site, enters the Columbia River at several locations associated with former plutonium production reactors at the Site. Strontium-90 is of concern to humans and the environment because of its moderately long half-life (29.1 years), its potential for concentrating in bone tissue, and its relatively high energy of beta decay. Although strontium-90 in the environment is not a new issue for the Hanford Site, recent studies of near-river vegetation along the shoreline near the 100 Areas raised public concern about the possibility of strontium-90-contaminated groundwater reaching the riverbed and fall chinook salmon redds. To address these concerns, DOE asked Pacific Northwest National Laboratory (PNNL) to prepare this report on strontium-90, its distribution in groundwater, how and where it enters the river, and its potential ecological impacts, particularly with respect to fall chinook salmon. The purpose of the report is to characterize groundwater contaminants in the near-shore environment and to assess the potential for ecological impact using salmon embryos, one of the most sensitive ecological indicators for aquatic organisms. Section 2.0 of the report provides background information on strontium-90 at the Hanford Site related to historical operations. Public access to information on strontium-90 also is described. Section 3.0 focuses on key issues associated with strontium-90 contamination in groundwater that discharges in the Hanford Reach. The occurrence and distribution of fall chinook salmon redds in the Hanford Reach and characteristics of salmon spawning are described in Section 4.0. Section 5.0 describes the regulatory standards and criteria used to set action levels for strontium-90. Recommendations for initiating additional monitoring and remedial action associated with strontium-90 contamination at the Hanford Site are presented in Section 6

  17. Strontium-90 at the Hanford Site and its ecological implications

    Energy Technology Data Exchange (ETDEWEB)

    RE Peterson; TM Poston

    2000-05-22

    Strontium-90, a radioactive contaminant from historical operations at the U.S. Department of Energy (DOE) Hanford Site, enters the Columbia River at several locations associated with former plutonium production reactors at the Site. Strontium-90 is of concern to humans and the environment because of its moderately long half-life (29.1 years), its potential for concentrating in bone tissue, and its relatively high energy of beta decay. Although strontium-90 in the environment is not a new issue for the Hanford Site, recent studies of near-river vegetation along the shoreline near the 100 Areas raised public concern about the possibility of strontium-90-contaminated groundwater reaching the riverbed and fall chinook salmon redds. To address these concerns, DOE asked Pacific Northwest National Laboratory (PNNL) to prepare this report on strontium-90, its distribution in groundwater, how and where it enters the river, and its potential ecological impacts, particularly with respect to fall chinook salmon. The purpose of the report is to characterize groundwater contaminants in the near-shore environment and to assess the potential for ecological impact using salmon embryos, one of the most sensitive ecological indicators for aquatic organisms. Section 2.0 of the report provides background information on strontium-90 at the Hanford Site related to historical operations. Public access to information on strontium-90 also is described. Section 3.0 focuses on key issues associated with strontium-90 contamination in groundwater that discharges in the Hanford Reach. The occurrence and distribution of fall chinook salmon redds in the Hanford Reach and characteristics of salmon spawning are described in Section 4.0. Section 5.0 describes the regulatory standards and criteria used to set action levels for strontium-90. Recommendations for initiating additional monitoring and remedial action associated with strontium-90 contamination at the Hanford Site are presented in Section 6

  18. Accumulation of strontium 90 and cesium 137 in some hydrobionts

    International Nuclear Information System (INIS)

    Boyadzhiev, A.; Keslev, D.; Kerteva, A.; Novakova, E.

    1974-01-01

    Factors responsible for the accumulation of strontium 90 and cesium 137 in some plant organisms, characteristic for fishes in Bulgarian fresh-water reservoirs and in Black Seawater, were examined. The investigated samples were taken during spring, summer and autumn-winter seasons 1967/1968. Each sample burnt to ashes at 450 0 C was examined for strontium 90 and cesium 137 content as well as stable isotopes of calcuim and potassium. Accumulation factors for strontium 90 and cesium 137 were significantly higher in freshwater hydrobionts than in seawater hydrobionts. This could be explained by variations in the concentration of stable isotopes of calcium and potassium from freshwater reservoirs and from seawater. Potassium and calcium concentrations were relatively constant in seawater while in freshwater they were significantly variable. Accumulation factors for these radionuclides increased according to the amount of rain and the altitude above sea level. Strontium 90 was deposited mostly in fins, less in scales and least in the meat of fishes; cesium 137 was mainly deposited in the meat and less in the other parts of fishes. The highest accumulation factors for strontium 90 were determined in fishes and for cesium 137 in plant organisms. The most convenient plant and fish species for tracing radioactive contamination of freshwater reservoirs and in the Black Sea were indicated. (A.B.)

  19. Bulgarian regional patterns of contamination by global fallout (strontium 90)

    International Nuclear Information System (INIS)

    Boyadzhiev, A.; Shopov, N.; Simova, G.; Andreev, E.; Mikha lov, M.G.

    1980-01-01

    For selected districts in the country, mean annual atmospheric precipitation rates were related to strontium-90 contents in milk over the period 1970-1977. Strontium-90 in milk was determined by the method of Popov, using Va-Z-310 counters for activity measurements. The impact of annual precipitation means was examined by monofactorial spread analysis, with sites distributed into three groups according to precipitation rates observed over longer time periods: up to 650 l/m 2 from 650 to 750 l/m 2 ; and above 750 L/M 2 . Values of coefficient F were estimated, representing the ratio of group to random spreads. These figures were compared with critical values in Student's tables for 0.05 significance level. The F data indicated a definite alternative relationship to exist between strontium-90 amounts in mils and annual precipitation rates, which is prognostically meaningful from the strandpoint of radiological protection of the population

  20. Strontium-90 and cesium-137 in freshwater from May 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Strontium-90 and cesium-137 in freshwater measured in May 1984 are given in pCi/l. The sampling point is 1, Kasumigaura-Lake (Ibaraki). Collection and pretreatment of samples, preparation of samples for analysis, separation of strontium-90 and cesium-137, determination of stable strontium, calcium and potassium, and counting are described. The sample was passed through a cation exchange column. After the radiochemical separation, the mounted precipitates were counted for activity using low background beta counters normally for 60 minutes. (Mori, K.)

  1. Strontium-90 content of human bone collected in 1967

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Patti, F.

    1969-01-01

    This report follows report CEA-R-3381 and presents the strontium 90 content of human bones collected in 1967 in the Paris area. The main trend is much the same as during 1966; contamination levels are falling down in infants up to 5 year old. Beyond this age, the values are the same or experience a slight increase. (authors) [fr

  2. Strontium-90 and cesium-137 in fresh water

    International Nuclear Information System (INIS)

    1978-01-01

    Japan Chemical Analysis Center has analysed the strontium-90 and Cesium-137 contents in fresh water from 7 prefectures in Japan by the commission of Science and Technology Agency of Japanese Government. The method described in ''Radioactivity Survey Data in Japan No. 43 (NIRS-RSD-43, 1977) was applied to the analysis of these two radionuclides in samples. (author)

  3. Determination of strontium-90 from direct separation of yttrium-90 by solid phase extraction using DGA Resin for seawater monitoring.

    Science.gov (United States)

    Tazoe, Hirofumi; Obata, Hajime; Yamagata, Takeyasu; Karube, Zin'ichi; Nagai, Hisao; Yamada, Masatoshi

    2016-05-15

    It is important for public safety to monitor strontium-90 in aquatic environments in the vicinity of nuclear related facilities. Strontium-90 concentrations in seawater exceeding the background level have been observed in accidents of nuclear facilities. However, the analytical procedure for measuring strontium-90 in seawater is highly demanding. Here we show a simple and high throughput analytical technique for the determination of strontium-90 in seawater samples using a direct yttrium-90 separation. The DGA Resin is used to determine the abundance of strontium-90 by detecting yttrium-90 decay (beta-emission) in secular equilibrium. The DGA Resin can selectively collect yttrium-90 and remove naturally occurring radionuclides such as (40)K, (210)Pb, (214)Bi, (238)U, and (232)Th and anthropogenic radionuclides such as (140)Ba, and (140)La. Through a sample separation procedure, a high chemical yield of yttrium-90 was achieved at 95.5±2.3%. The result of IAEA-443 certified seawater analysis (107.7±3.4 mBq kg(-1)) was in good agreement with the certified value (110±5 mBq kg(-1)). By developed method, we can finish analyzing 8 samples per day after achieving secular equilibrium, which is a reasonably fast throughput in actual seawater monitoring. By processing 3 L of seawater sample and applying a counting time of 20 h, minimum detectable activity can be as low as 1.5 mBq kg(-1), which could be applied to monitoring for the contaminated marine environment. Reproducibility was found to be 3.4% according to 10 independent analyses of natural seawater samples from the vicinity of the Fukushima Daiichi Nuclear Power Plant in September 2013. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Strontium-90 and cesium-137 in service water

    International Nuclear Information System (INIS)

    1979-01-01

    Prefectural public health laboratories and institutes and Japan Chemical Analysis Center have analysed the contents of strontium-90 and cesium-137 in service water under the commission of Science and Technology Agency. At each prefectural public health laboratories and institutes, 100 literes of service water (8 prefectures, water from the intake of each station of water works) and tap water (32 prefectures) were collected as sample twice a year. The samples were filtrated with large filter papers after addition and mixture of both some carries. The filtration was then applied on a column filled the sodium cation exchange resin, and all the cations were absorbed on it. These resin and filter papers were collected at Japan Chemical Analysis Center. At Japan Chemical Analysis Center, these collected samples were radiochemically analysed for strontium-90 and cesium-137 using the method applied for the analysis of rain and dry fallout materials. (author)

  5. Strontium-90 and cesium-137 in total diet

    International Nuclear Information System (INIS)

    1977-01-01

    Under the commission of Science and Technology Agency, Japan Chemical Analysis Center has analysed total diet samples collected from 30 prefectures (2 times per year), and determined to content of strontium-90 and cesium-137 in these samples. Each Prefectural public health laboratories and institutes have collected all the daily regular diet consumed for five persons, namely three meals and other eating between meals, for radiochemical analysis in polyethylene containers. These samples were collected to Japan Chemical Analysis Center after carbonization without smoke rising in the large stainless dish. At Japan Chemical Analysis Center, these samples were asked in an electric muffle furnance. And the ask to which both some carriers and hydrochloric acid were added, was destroyed under heating. The nuclides were dissolved into hydrochloric acid and filtrated, after it was added with nitric acid and heated to dryness. The filtrates was analysed for strontium-90 and cesium-137 using the method recommended by Science and Technology Agency. (author)

  6. Determination of strontium-90 in the environmental samples at PINSTECH

    International Nuclear Information System (INIS)

    Perveen, N.; Aziz, A.

    1979-01-01

    Strontium-90 a bone seeking radionuclide and a long lived beta emitter is one of the toxic radionuclides detected in the environment arising mainly from the fall out from nuclear detonations. Its concentration in various environmental media such as air, precipitation, surface water, vegetables and other items of diet was measured. This report describes the method of collection, treatment and radiochemical analyses of environmental samples for the determination of Sr-90. The levels of Sr-90 concentration in these media are also recorded. (authors)

  7. Strontium-90 in ion-exchange resin used in the Australian FIEFS network

    International Nuclear Information System (INIS)

    Wise, K.N.

    1977-10-01

    In order to determine monthly strontium-90 fallout deposited at the eight Australian monitoring stations, account must be taken of the level of strontium-90 contamination of the ion-exchange resin as prepared for use in the FIEFS. This procedure has always been important in monitoring strontium-90 fallout deposit in Australia because the level of strontium-90 contamination of ion-exchange resin, supplied by manufacturers in the Northern Hemisphere, has remained of the same order of magnitude as the monthly fallout deposit in the Southern Hemisphere

  8. Radiotherapy of the glaucoma using ophthalmic strontium-90

    International Nuclear Information System (INIS)

    Ayad, M.; Saleh, A.M.M.; Metawi, A.M.M.; Abdin, F.H.; Kamali, Kh.; Haddad, S.

    2001-01-01

    The study of the effect of beta-rays on the ciliary body of the eye which leads to the reduction of the secretion of aqueous humor resulting in lowering of the intraocular pressure, has been accomplished by using a radioisotope such as strontium-90 as a pure beta-rays of high absorbed doses ranging between 10 Gy up to 300 Gy. The doses vis : 200, 250, 300 Gy can lead to a significant lowering of the intra ocular pressure (.O.P) with an increase of the tonometer reading by 27% the increase of the tonometer readings could be translated as a marked lowering in the ocular tension, which is most probably due to the effect of b-rays

  9. Chemical Separation Technique of Strontium-90 in the Soil Water as theStandard Methods for Environmental Radioactivity Analysis

    International Nuclear Information System (INIS)

    Ngasifudin-Hamdani; Suratman; Djoko-Sardjono, Ign; Winduanto-Wahyu SP

    2000-01-01

    Research about separation technique of strontium-90 from its materialmatrix using chemical precipitation method has been done. That technique wasapplied on the detection of radionuclide strontium-90 containing in the soilwater of near nuclear reactor facility P3TM BATAN in three location. The twoimportant parameters used in this technique were growth time of Y-90 andstirring time. The result shown that activity of strontium-90 in the pos-01was between 1.801x10 -19 - 9.616x10 -17 μCi/cm 3 , pos-02 was8.448x10 -19 - 1.003x X 10 -16 μCi/cm 3 and pos-03 was 6.719x10 -19 - 11.644x10 -16 μCi/cm 3 . From those data shown that activity of Sr-90in the soil water of near nuclear reactor facility P3TM BATAN was still belowthe limit value of maximum concentration permitted i.e. 4.0x10 -7 -3.5x10 -6 μCi/cm 3 . The statistic test using analysis of varian twofactorial with random block design shown that the activity of Sr-90 in thesoil water was influenced by the interaction which take place between growthlong time of Y-90 and stirring long time. (author)

  10. Separation and determination of strontium-90 in burnout nuclear fuel

    International Nuclear Information System (INIS)

    Khermann, A.; Katsvinkel', I.

    1975-01-01

    Developed was a simple and selective chromatographic method of the separation of strontium-90, by the content of which it is possible to judge about the degree of nuclear fuel burnup. Among the studied ion exchangers for strontium separation the best results are exhibited by strongly acidic organic cationite, i.e. vofatite (on the base of styrene, 8%-divinylbenzene) in the H + form. Elution was performed by hydrochloric or oxalic acids. The method allows to achieve a high degree of Sr-90 purification from other fission products. Using the method the Sr-90 content was determined in burnup fuel of the fuel elements of EK-10 type. At the fuel storage period less than 2 years it becomes necessary to determine both Sr-90 and Sr-89. Determination of Sr-90 in the presence of Sr-89 was made by daughter product of Sr-90 - Y-90, which is separated in ion-exchange coloumn. Some other methods of Sr-90 determination in the presence of Sr-89 are noted

  11. Strontium-90 (90Sr) determination using liquid scintillation counting

    International Nuclear Information System (INIS)

    Cheberle, L.T.V.; Rosa, M.M.L.; Ferreira, M.T.; Taddei, M.H.T.

    2015-01-01

    This procedure describes a method for separation and measurement of strontium 90 Sr in water, soils, and biological samples. Water samples may be concentrated using evaporation or calcium phosphate coprecipitation. Soils and biological materials must be dissolved using wet digestion. Tracers and carriers must be added before the attack. Radioactive strontium is separated employing a specific resin before determination by liquid scintillation counting using the double energetic window method. The resin is used to concentrate strontium from samples. Stable strontium is used to monitor method yields and correct results to improve precision and accuracy. The presence of elemental strontium in the sample may bias the gravimetric yield determination. If it is suspected that natural strontium is present in the sample, its concentration should be determined by a suitable means (ICP), and the yield calculation properly modified. Sr-Spec resin with an 8M HNO 3 load solution is used to effectively remove 140 Ba and 40 K isotopes, as well as other interferences from the matrix. Tetravalent plutonium, neptunium, cerium and ruthenium, however, are not removed using nitric acid. The radiochemical procedure was tested using PROCORAD intercomparison exercises and PNI samples. (author)

  12. Strontium-90 and cesium-137 in milk (consuming districts) (from May. 1982 to Mar. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in milk (consuming districts from May 1982 to Mar. 1983) were determined. Commercial milk was purchased in 25 consuming districts. The results are shown in a table. (J.P.N.)

  13. Level of radioactive strontium-90, potassium-40 in bone tissues of sheep

    International Nuclear Information System (INIS)

    Bandi, D.; Andrei, S.; Ehnkhtuya, Ts.

    1992-01-01

    We have studied the level of strontium-90 and potassium-40 in bone tissues of sheep. Level of the radioactive elements in its bone tissues decreases depending on its ripeness, but a strong decrease was observable in its old ages

  14. Strontium-90 and cesium-137 in milk (consuming districts) (from May 1982 to Aug. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in milk (consuming districts from May to Aug. 1982) were determined. Commercial milk was purchased in 20 consuming districts. The results are shown in a table. (Namekawa, K.)

  15. Radiation protection data sheets for the use of Strontium 90-Yttrium 90 in unsealed sources

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This radiation protection data sheet is intended for supervisors and staff in the different medical, hospital, pharmaceutical, university and industrial laboratories and departments where Strontium 90-Yttrium 90 is handled, and also for all those involved in risk prevention in this field. It provides essential data on radiation protection measures during the use of Strontium 90-Yttrium 90 in unsealed sources: physical characteristics, risk assessment, administrative procedures, recommendations, regulations and bibliography

  16. Simulating the Transfer of Strontium-90 from Soil to Leafy Vegetables by Using Strontium-88

    OpenAIRE

    Kuke, Ding; Shujuan, Liu; Yingxue, He; Dong, Yan; Fengshou, Zhang; Shuifeng, Wang; Jinghua, Guo; Wei, Zhang; Xin, Wang; Xiaoyan, Jiang

    2016-01-01

    The transfer, from soil to Chinese cabbage and spinach, of radioactive strontium-90 released as a result of accidents in nuclear power stations was studied using a stable isotope of strontium, namely nuclide strontium-88 (88Sr). The study led to an experimental model for assessing the hazard of radionuclide strontium-90 (90Sr) entering the food chain and for predicting the risk to food safety. Chinese cabbage and spinach were grown in pots in a greenhouse and irrigated with deionized water co...

  17. Strontium-90 in milk and mixed diet in the Czech Republic

    International Nuclear Information System (INIS)

    Bartuskova, M.; Schlesingerova, E.

    2014-01-01

    Among various activities of National Radiation Protection Institute (SURO) monitoring of radionuclides in environment and food chain plays an important role. The monitoring takes place in frame of Czech Radiation Monitoring Network (RMN). Determinations of 90 Sr are performed according to the monitoring schedule of RMN. Strontium-90 was released into environment during the tests of nuclear weapons in the fifties and sixties of XX. century and to some extent in 1986 owing to the Chernobyl accident. Strontium is a chemical analogue of calcium and accordingly when entering a mammal body, it behaves very much like calcium. A large portion of the strontium will accumulate in bone and like calcium it transfers to milk. Since the Sr uptake by the human body from milk is an important pathway for radiostrontium incorporation, milk and milk powder are good indicators of 90 Sr content in human diet. Along with milk and milk powder, mixed diet samples composed of representative locally purchased food items according to food consumption statistics are also analysed for 90 Sr.The analyses are made using oxalate precipitation method, when interfering radionuclides are removed by precipitation scavenging and after its ingrowth 90 Y is separated and repeatedly measured by gas flow proportional counter. Strontium-90 activity is calculated as equal to 90 Y activity in equilibrium. Time evolution of 90 Sr activities in milk in Northern Moravia region (1988 present) and in Prague (1965 - present), in milk powder from the regions of the Czech Republic and in the mixed diet samples from the whole republic is presented on the poster. A very small increase due to the Chernobyl accident can be seen in milk. After the ban of atmospheric tests the level of 90 Sr has steadily been falling. The decrease is caused by radioactive decay and migration of the radionuclide in the environment. Due to this decrease activity concentrations in many samples have recently fallen under minimum significant

  18. Strontium-90 in milk and mixed diet in the Czech Republic

    International Nuclear Information System (INIS)

    Bartuskova, M.; Schlesingerova, E.

    2014-01-01

    Among various activities of National Radiation Protection Institute (SURO) monitoring of radionuclides in environment and food chain plays an important role. The monitoring takes place in frame of Czech Radiation Monitoring Network (RMN). Determinations of 90 Sr are performed according to the monitoring schedule of RMN. Strontium-90 was released into environment during the tests of nuclear weapons in the fifties and sixties of XX. century and to some extent in 1986 owing to the Chernobyl accident. Strontium is a chemical analogue of calcium and accordingly when entering a mammal body, it behaves very much like calcium. A large portion of the strontium will accumulate in bone and like calcium it transfers to milk. Since the Sr uptake by the human body from milk is an important pathway for radiostrontium incorporation, milk and milk powder are good indicators of 90 Sr content in human diet. Along with milk and milk powder, mixed diet samples composed of representative locally purchased food items according to food consumption statistics are also analysed for 90 Sr.The analyses are made using oxalate precipitation method, when interfering radionuclides are removed by precipitation scavenging and after its ingrowth 90 Y is separated and repeatedly measured by gas flow proportional counter. Strontium-90 activity is calculated as equal to 90 Y activity in equilibrium. Time evolution of 90 Sr activities in milk in Northern Moravia region (1988 present) and in Prague (1965 - present), in milk powder from the regions of the Czech Republic and in the mixed diet samples from the whole republic is presented on the poster. A very small increase due to the Chernobyl accident can be seen in milk. After the ban of atmospheric tests the level of 90 Sr has steadily been falling. The decrease is caused by radioactive decay and migration of the radionuclide in the environment. Due to this decrease activity concentrations in many samples have recently fallen under minimum significant

  19. Calcium and Strontium in Swedish Waters and Fish, and Accumulation of Strontium-90

    Energy Technology Data Exchange (ETDEWEB)

    Agnedal, P O

    1966-04-15

    The purpose of this study has been to investigate the correlation between calcium and strontium in fish in relation to the concentration of these elements in the water. An investigation of the uptake of strontium-90 has also been made and permissible levels of strontium-90 in the water is calculated based upon the uptake in fish muscle tissues. Lakes with calcium concentrations between 2 - 63 mg/l have been studied and samples from the Baltic coastal water are also included. Three fish species are studied, viz. pike (Esox lucius (L.)), perch (Perca fluviatilis (L.)) and roach (Leuciscus rutilus (L.)). Bones, muscle tissues and skin + scales have been analysed. Strontium-90 measurements have been made showing an increase in both water and fish. Calculations show that in water with about 2 mg Ca/l a 10-fold increase of the existing strontium-90 level might give strontium-90 concentrations in fish muscle tissues close to what is permissible. In lakes with calcium concentrations 20 - 40 mg/l the permissible levels for drinking water will be exceeded before the fish consumption would have to be restricted.

  20. Strontium-90 accumulation in fowl and its migration into egg following chromic intake with forage

    International Nuclear Information System (INIS)

    Koldaeva, K.A.; Sarapul'tsev, I.A.

    1975-01-01

    Accumulation of strontium-90 in different organs of hens and its transfer ot eggs have been studied at chronic feeding with the isotope. The feed consisted of potato and wheat grown on plots artificially contaminated with strontium-90. The duration of the experiment is 30 days during which the hens lay 35 eggs. Strontium-90 and calcium are determined in the femur, shoulder, breastbone, skull, rib, vertebrae, and muscles. Determination errors do not exceed 10 and 5% for the isotope and calcium respectively. Concentration of stronium-90 and calcium in different bones and in muscles of laying hens and roosters after a month's feeding with the isotope presented. The isotope concentration in bones of hens 3 to 4 times higher than in bones of roosters while the muscle concentration is similar in both cases. The higher content of strontium-90 per g of bone tissue calcium in hens can be explained by a higher level of calcium metabolism during the laying period. Data on strontium-90 and calcium concentration in eggs are also presented. The bulk of the isotope accumulates in the eggshell (96.4%). One egg contains an average of 31% of the daily strontium intake

  1. Calcium and Strontium in Swedish Waters and Fish, and Accumulation of Strontium-90

    International Nuclear Information System (INIS)

    Agnedal, P.O.

    1966-04-01

    The purpose of this study has been to investigate the correlation between calcium and strontium in fish in relation to the concentration of these elements in the water. An investigation of the uptake of strontium-90 has also been made and permissible levels of strontium-90 in the water is calculated based upon the uptake in fish muscle tissues. Lakes with calcium concentrations between 2 - 63 mg/l have been studied and samples from the Baltic coastal water are also included. Three fish species are studied, viz. pike (Esox lucius (L.)), perch (Perca fluviatilis (L.)) and roach (Leuciscus rutilus (L.)). Bones, muscle tissues and skin + scales have been analysed. Strontium-90 measurements have been made showing an increase in both water and fish. Calculations show that in water with about 2 mg Ca/l a 10-fold increase of the existing strontium-90 level might give strontium-90 concentrations in fish muscle tissues close to what is permissible. In lakes with calcium concentrations 20 - 40 mg/l the permissible levels for drinking water will be exceeded before the fish consumption would have to be restricted

  2. Forecast of strontium 90 accumulation in the crop of agricultural cultures

    International Nuclear Information System (INIS)

    Dergunov, I.D.; Moroz, V.D.

    1980-01-01

    A possibility to determine the level of contamination with strontium-90 of agricultural crops according to its content in young plants as studied. The investigations have been carried out under conditions of vegetational experiment with cotton on light, typical, dark grey soils and meadow spoils. The samples in the phase of 20 day old plants and in the period of ripening have been selected for radiometric analysis. Activity has been measured according to β-irradiation of nuclide. Tbe measurement results point to the existence of certain connection between radiostrontium content in young plants and in the fibre crops. Close connection is also found between strontium-90 content in young plants and in the cotton seeds. Direct proportional dependence between strontium-90 content in young and grown-up plants is established. Linear coefficients for cotton are obtained which can be used for forecasting the level of cotton fibre contamination with radiostrontium according to its content in 20 day old plants

  3. Investigations into the transfer of cesium 137 and strontium 90 in selected exposure pathways

    International Nuclear Information System (INIS)

    Roemmelt, R.; Hiersche, L.; Wirth, E.

    1991-12-01

    This research project investigates the behaviour of radiocesium and strontium 90 in natural conifer forest sites and derives corresponding transfer factors for radioecological calculations. As a point of particular interest the question was investigated in how far the requirements of the different mushroom species and the properties of the forest soil bear on the dynamics and transfer rate of radiocesium and strontium 90. To complement the investigations, autotrophic plants were included. The results of these studies are compared with the behaviour of the same radionuclides on farmland. The differences are discussed. (orig./HP) [de

  4. Laboratory scale stabilization of N-springs groundwater strontium-90 using phosphatic materials

    International Nuclear Information System (INIS)

    Moody, T.E.; Petersen, S.W.; Torne, E.G.; Vlcakova, J.; Higginbotham, J.F.

    1996-09-01

    This document presents the results of a laboratory study designed to evaluate the ability of phosphatic materials to sorb strontium-90 from soil and groundwater. This study was initiated to investigate the potential use of phosphatic materials as permeable geochemical barriers for groundwater contaminated with strontium-90. Groundwater discharges to the Columbia River create potential human food chain hazards; therefore, it is imperative to immobilize the contamination before it reaches the river. Phosphate materials have been proven by various researchers to be chemical compounds that combine with contaminant metals forming into insoluble metal-phosphate minerals. These minerals are stable and insoluble under normal soil conditions

  5. Strontium-90 and cesium-137 in sea fish (from Oct. 1981 to Jun. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in sea fishes (from Oct. 1981 to Jun. 1982) were determined. Fish was collected from eight sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are shown in a table. (Namekawa, K.)

  6. Strontium-90 and cesium-137 in sea fish (from Jun. 1982 to Dec. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in sea fish (from Jun. to Dec. 1982) were determined. Fish was collected from 22 sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are sown in a table. (Namekawa, K.)

  7. Strontium-90 and cesium-137 in sea water (from Jul 1984 to Sep 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Monitoring results are presented on strontium-90 and cesium-137 contents in sea water of 11 sampling points all over Japan from Hokkaido to Okinawa coast. Sampling points were selected by the criterion that the effect of terrestrial fresh water and atmospheric precipitation was expected to be ignorable. Sample collection was carried out in the Period from July to September, 1984. With a special care for prevention of any contamination. The collected sea water samples were acidified immediately and they were served for radiochemical separation and purification of strontium-90 and cesium-137. Radiation counting was made for yttrium-90 hydroxide sample and cesium chloroplatinate sample with a low background beta counter normally for 60 minutes. As for strontium-90 contents in sea water, they were ranged from 0.07 +- 0.010 pCi/l (Mutsu Bay, Aomori) to 0.11 +- 0.012 pCi/l (Off Niigata Port, Niigata) and the average value was 0.09 pCi/l. As for cesium-137 contents, they were ranged from 0.08 +- 0.011 pCi/l (Ise Bay, Aichi) to 0.14 +- 0.012 pCi/l (Yamaguchi Bay, Yamaguchi) and the average value was 0.106 pCi/l. It is clarified that no abnormal values were determined for strontium-90 or cesium-137 contents in coastal sea water around Japan from a fallout origin. (Takagi, S.)

  8. Strontium 90 activity in drinking water of Paris area from 1963 to 1972

    International Nuclear Information System (INIS)

    Jeanmaire, L.; Patti, F.; Gros, R.

    1976-01-01

    Strontium 90 was determined in drinking water of the Southern Paris area from 1963 to 1972. Activities usually below 1pCi/l were related to the Seine river flow and decreased with a half-life of about five years [fr

  9. 10 CFR 35.491 - Training for ophthalmic use of strontium-90.

    Science.gov (United States)

    2010-01-01

    ... the requirements in paragraph (b) of this section and has achieved a level of competency sufficient to... require the authorized user of strontium-90 for ophthalmic radiotherapy to be a physician who— (a) Is an...; (iii) Mathematics pertaining to the use and measurement of radioactivity; and (iv) Radiation biology...

  10. Toxicity of strontium-90 depending on the way of its administration to animal organisms

    International Nuclear Information System (INIS)

    Shvedov, V.L.

    1978-01-01

    Toxicity of strontium-90 administered orally is almost thrice lower than that after parenteral administration. The values of the doses absorbed in the critical organ of rats, corresponding to LDsub(50/30), were 2400 to 2600 rad irrespective of the route of the radionuclide administration

  11. Strontium-90 and cesium-137 in sea fish (from Nov. 1982 to Jun. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in sea fish (from Nov. 1982 to Jun. 1983) were determined. Fishes were collected from eight sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are shown in a table. (J.P.N.)

  12. Strontium-90 and cesium-137 in total diet (from Jun. 1982 to Dec. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in total diet (from Jun. to Dec. 1982) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 22 sampling locations. The results are shown in a table. (Namekawa, K.)

  13. Strontium-90 and cesium-137 in total diet (from Nov. 1982 to Jun. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in total diet (from Nov. 1982 to Jun. 1983) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 26 sampling locations. The results are shown in a table. (J.P.N.)

  14. Strontium-90 and cesium-137 in total diet (from Oct. 1981 to Jul. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in total diet (from Oct. 1981 to Jul. 1982) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 26 sampling locations. The results are shown in a table. (Namekawa, K.)

  15. Strontium-90 and cesium-137 in rice (consuming districts) (from Nov. 1982 to Jan. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in rice (consuming districts from Nov. 1982 to Jan. 1983) were determined. Polished rice was collected in eight consuming areas when new crops were first put on sale. The results are shown in a table. (J.P.N.)

  16. Strontium-90 and cesium-137 in soil (from Jun. 1983 to Sept. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Results are presented for the determination of strontium-90 and cesium-137 in soils in Japan. Twenty-seven sampling points were selected all over Japan from Hokkaido to Okinawa by the criteria that the points were spacious and flat without past disturbance and those located in a forest, in a stony area or inside of river banks should be avoided. Soils were taken from two layers of depth, 0 to 5 cm and 5 to 20 cm. After drying, soils were passed through a 2 mm sieve and were employed for radiochemical leaching, separation, and purification of strontium-90 or cesium-137. Radioactivity of strontium-90 or cesium-137 was determined with a low background beta counter normally for 60 minutes. Determined values are presented as pCi/kg and mCi/km 2 for two different depth layers. As for strontium-90 contents, they were ranged from 13.0 +- 3.3 pCi/kg-dry (Aomori, 5 to 20 cm) to 1300 +- 20 pCi/kg-dry (Oota, Shimane Pref., 0 to 5 cm), or from 1.1 +- 0.14 mCi/km 2 (Tsuyama, Okayama Pref., 0 to 5 cm) to 50.0 +- 1.7 mCi/km 2 (Sapporo, 5 to 20 cm). As for cesium-137 contents, they were ranged from 0.5 +- 2.2 pCi/kg-dry (Saga, 5 to 20 cm) to 4700 +- 40 pCi/kg-dry (Oota, Shimane Pref., 0 to 5 cm) or from 0.1 +- 0.42 mCi/km 2 (Saga, 5 to 20 cm) to 120.0 +- 2.0 mCi/km 2 (Oota, Shimane Pref., 5 to 20 cm), and the variance for cesium-137 values were larger than those for strontium-90. Seasonal or local tendency for the contents of the two nuclides were not clarified. (Takagi, S.)

  17. Strontium-90 and cesium-137 in sea sediments (from May 1984 to Sep 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Strontium-90 and cesium-137 monitoring results are presented for sea sediment samples of 12 sampling points located all over Japan from Tomari, Hokkaido to Kinnakagusuku Bay, Okinawa. The samples were collected by considering of enough sea water depth, no significant sedimental movement and sediment characteristics, and by employing a conventional sampling device. Approximately 4 kg-wet sample was dried and was passed through a 20 cm mesh sieve. After adding of strontium and cesium carriers, strontium-90 and cesium-137 were leached with a hot hydrochloric acid solution. The leachate was treated by ion exchange and coprecipitation to concentrate and isolate strontium-90 or cesium-137. Radiation counting was carried out by employing a low background beta counter usually for 60 minutes for the samples of strontium carbonate or cesium chloroplatinate. Determined strontium-90 contents in sea sediment were distributed from 0 +- 2.7 pCi/kg-dry (Mutsu Bay, Aomori, Yamaguchi Bay, Yamaguchi) to 14 +- 3.2 pCi/kg-dry (Mutsu Bay), and those of cesium-137 were from 9 +- 3.5 pCi/kg-dry (Mutsu Bay) to 250 +- 9 pCi/kg-dry (Off-Niigata Port, Niigata). Local variation of the contents of these radionuclides was very large, and for seasonal variation, it was also found large for the both nuclides content in the Mutsu Bay samples of May, 1984 and August 1984, as for strontium-90, 0 +- 2.7 pCi/kg and 14 +- 3.2 pCi/kg, for cesium-137, 9 +- 3.5 pCi/kg and 200 +- 8 pCi/kg, respectively. (Takagi, S.)

  18. 10 CFR 32.103 - Schedule D-prototype tests for ice detection devices containing strontium-90.

    Science.gov (United States)

    2010-01-01

    ... water and the strontium-90 shall be considered leakage. (e) Observations. After each of the tests... 10 Energy 1 2010-01-01 2010-01-01 false Schedule D-prototype tests for ice detection devices... § 32.103 Schedule D—prototype tests for ice detection devices containing strontium-90. An applicant for...

  19. A distribution of adsorbed forms of cesium 137 and strontium 90 in flood-plain formations of Sozh river

    International Nuclear Information System (INIS)

    Kuznetsov, V.A.; Generalova, V.A.

    1999-01-01

    The distribution of strontium 90 and cesium 137 forms in flood-plain geochemical system 'alluvial deposits - flood-plain turf - humus horizon - soil-source rock', where sorption and colloidal processes play main role in the isotopes migration, was studied. The bulk amount of strontium 90 is presented in adsorbed form in all investigated objects, whereas only 6% of cesium 137 amount in alluvial deposits, flood-plain turf and humus horizon is in adsorbed form. The content of exchange forms of cesium 137 and strontium 90 increases with the depth of the layer. The race of this increase for strontium 90 is large than for cesium 137. The distribution of radionuclides through the different parts of flood-plain of Sozh river has some distinctions due to more lability of adsorbed strontium 90 forms in comparison with cesium 137 ones

  20. Dosage of strontium 90 in human bone ashes; Dosage du strontium 90 sans les cendres d'os humain

    Energy Technology Data Exchange (ETDEWEB)

    Patti, F; Jeanmaire, L [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The determination of {sup 90}Sr in bones by dosage of its daughter product {sup 90}Y is a 4-step process: 1) elimination of the phosphate ions by precipitation of the Ca and Sr as oxalate in the presence of acid; 2) reduction in the calcium concentration to a suitable level by the addition of a known volume of nitric acid (a single precipitation is sufficient), the precipitation yield of the strontium nitrate is checked by the measurement of the amount of {sup 85}Sr added as tracer; 3) purification by a yttrium hydroxide precipitation; 4) extraction at equilibrium of the {sup 90}Y which is counted to give the concentration. By using 50 gm of ash it is possible to detect about 0.1 pCi of {sup 90}Sr per gram of calcium. The advantages of this technique: -) treatment of a large quantity of bone ash -) the use of a small volume of nitric acid (less than 2 ml/g of ash, and -) the various operations present no difficulty. (authors) [French] Determination du Sr dans les os par dosage de son produit de filiation {sup 90}Y. Principe du dosage: 1 - Eliminer les ions phosphates par precipitation du calcium et du strontium sous forme d'oxalate en milieu acide. 2 - Reduire la concentration en calcium a un niveau convenable par addition d'un volume determine d'acide nitrique (une seule precipitation est necessaire). Le rendement de precipitation du nitrate de strontium est controle par la mesure de {sup 85}Sr ajoute comme traceur. 3 - Purifier par une precipitation d'hydroxyde d'yttrium. 4 - Extraire a l'equilibre l'{sup 90}Y qui eat compte pour determiner le {sup 90}Sr. En traitant 50 g de cendre, il est possible de deceler de l'ordre de 0,1 pCi de {sup 90}Sr par gramme de calcium. Les 3 avantages de cette technique: 1 - traitement d'une quantite importante de cendres d'os, 2 - emploi d'un faible volume d'acide nitrique (moins de 2 ml/g de cendres), et 3 - les diverses operations ne presentent aucune difficulte.

  1. Strontium-90 and cesium-137 migration in trophic chain of cattle

    International Nuclear Information System (INIS)

    Zotov, V.G.; Sirotkin, A.N.; Isamov, N.N.

    1983-01-01

    Technique for determination of factors of radionuclide migration in cattle trophic chain, which can be used for forecasting probable contamination of food and cattle breeding products Under Uzbekistan conditions is suggested. It is shown that the factor of biological absorption (FBA) of strontiUm 90 by plants from grey desert soils is 3.7 times higher, than of cesium 137. Mentioned differences in soil-plants migration link are leveled and their FBA in food-milk, food-bone, food-mUscles links remain practically the same during radionuclide migration from food to milk and meat. During radionuclide migration in trophic chain of cattle in food-bone and food-muscles chains the concentration of strontium 90 in bone tissUe and cesium 137 in muscle tissue takes place

  2. Strontium-90 and cesium-137 in soil from May 1984 to July 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Strontium-90 and cesium-137 in soil measured throughout Japan from May to July 1984 are given in pCi/kg and mCi/km 2 . Sampling points are total of 8 from Kawabe-gun (Akita) to Ibasuki-gun (Kagoshima). Collection and pretreatment of samples, preparation of samples for analysis, separation of strontium-90 and cesium-137, determination of stable strontium, calcium and potassium, and counting are described. Soil was collected from the location in the spacious and flat area without past disturbance on the surface. Soil was taken from two layers of different depths, 0 aproximately 5 cm and 5 approximately 20 cm. After the radiochemical separation, the mounted precipitates were counted for activity using low background beta counters normally for 60 minutes. (Mori, K.)

  3. Strontium-90 sorption from fresh waters in the process of barium manganite modification

    International Nuclear Information System (INIS)

    Ryzhen'kov, A.P.; Egorov, Yu.V.

    1995-01-01

    Strontium-90 extraction by barium manganite from fresh water (natural non-salty water in open ponds) may be increased adding to the solution the sulfate anion containing reagents that modify a sorbent and chemically bind a sorbate. Heterogeneous anion-exchanging reaction of barium manganite transformation into barium sulfate-manganese dioxide and simultaneous coprecipitation of strontium sulfate (microelement) occur as a result of it. 9 refs., 4 figs., 1 tab

  4. Application of TREECS (trademark) to Strontium 90 for Borschi Watershed near Chernobyl, Ukraine

    Science.gov (United States)

    2012-08-01

    near Chernobyl , Ukraine by Mark S. Dortch PURPOSE: The Training Range Environmental Evaluation and Characterization System (TREECS™) (http... Chernobyl Nuclear Power Plant, Ukraine. At this site, TREECS™ was used as a modeling tool to predict the fate of radionuclides. This application also...Web site noted above. Borschi watershed is located 3 km south of the Chernobyl Nuclear Power Plant (Figure 1). Radio- strontium-90, 90Sr, which is a

  5. Surveillance of Strontium-90 in Foods after the Fukushima Daiichi Nuclear Power Plant Accident.

    Science.gov (United States)

    Nabeshi, Hiromi; Tsutsumi, Tomoaki; Uekusa, Yoshinori; Hachisuka, Akiko; Matsuda, Rieko; Teshima, Reiko

    2015-01-01

    As a result of the Fukushima Daiichi nuclear power plant (NPP) accident, various radionuclides were released into the environment. In this study, we surveyed strontium-90 ((90)Sr) concentrations in several foodstuffs. Strontium-90 is thought to be the third most important residual radionuclide in food collected after the Fukushima Daiichi, NPP accident after following cesium-137 ((137)Cs) and cesium-134 ((134)Cs). Results of (90)Sr analyses indicated that (90)Sr was detect in 25 of the 40 radioactive cesium (r-Cs) positive samples collected in areas around the Fukushima Daiichi NPP, ranging in distance from 50 to 250 km. R-Cs positive samples were defined as containing both (134)Cs and (137)Cs which are considered to be indicators of the after-effects of the Fukushima Daiichi NPP accident. We also detected (90)Sr in 8 of 13 r-Cs negative samples, in which (134)Cs was not detected. Strontium-90 concentrations in the r-Cs positive samples did not significantly exceed the (90)Sr concentrations in r-Cs negative samples or the (90)Sr concentration ranges in comparable food groups found in previous surveys before the Fukushima Daiichi NPP accident. Thus, (90)Sr concentrations in r-Cs positive samples were indistinguishable from the background (90)Sr concentrations arising from global fallout prior to the Fukushima accident, suggesting that no marked increase of (90)Sr concentrations has occurred in r-Cs positive samples as a result of the Fukushima Daiichi NPP accident.

  6. Rapid determination of strontium-89 and strontium-90 in food and environmental samples by Cerenkov counting

    International Nuclear Information System (INIS)

    Melin, Judith; Suomela, Jorma

    1995-01-01

    The method has been developed for emergency situations. Minimum detectable concentrations of 5 Bq/liter, kilogram of strontium-89 and strontium-90 respectively is achievable in the presence of nuclides considered to be released under accidental conditions. Result on the strontium-89 and strontium-90 content in a sample can be obtained within 12 hours. One technician can easily handle 8-10 samples during a working day of eight hours. The determination of the strontium isotopes is accomplished by monitoring the Cerenkov radiation from strontium-89 and yttrium-90 in a liquid scintillation counter. The latter is the daughter product of strontium-90. Prior to the Cerenkov counting the sample is separated from interfering nuclides by oxalate precipitation, chromate precipitation and HDEHP-extraction. The method has to be further improved and evaluated with respect to different soil types such as forest mineral soil layers, agricultural soils and pastures. Furthermore, the decontamination procedure should be evaluated for a sample containing freshly irradiated uranium. (author)

  7. Radiochemical determination of strontium-90 and cesium-137 in waters of the Pacific Ocean and its neighboring seas

    International Nuclear Information System (INIS)

    Borisenko, G.S.; Kandinskii, P.A.; Gedeonov, L.I.; Ivanova, L.M.; Petrov, A.A.

    1987-01-01

    Depending on the salinity of the water, two versions of strontium-90 and cesium-137 concentration from water samples are presented. Cesium-137 was concentrated by precipitating sparingly soluble mixed hexacyanoferrates (II), and strontium-90 by precipitating carbonates together with calcium. A scheme has been given for radiochemical analysis of the concentrates. Strontium-90 and cesium-137 contents in the waters of the Pacific Ocean and its neighboring seas have been determined by the radiochemical method described. The levels of radionuclide content in the water and atmospheric precipitations have been shown to be inter-related. Strontium-90 and cesium-137 contents in the surface water of the northwestern Pacific were found to be much lower in 1980 than in the early seventies. The area of technogenic radioactive pollution was found to persist in the region of the Columbia mouth into the Pacific Ocean

  8. Expedition of 5 strontium-90 (90Sr) sources toward tobacco Honduran

    International Nuclear Information System (INIS)

    Roas Z, N.; Morales C, M

    2000-01-01

    This report describes the different activities that were carried out in relation to the identification of 5 strontium-90 sources and the technical consultantship in the related to the administration of the permission in the face of the regulatory authority of the country, for the transfer from the sources to the tobacco hondurena. The report covers the operation related to smear tests, identification and packing of the labeled sources of the container, that which took place in the cellar 19 located in the properties of the tobacco Nicaraguan (TANIC), in the period of February 21 at May 5 the 2000

  9. Levels of strontium 90 in the environment at PINSTECH (Period 1979-1980)

    International Nuclear Information System (INIS)

    Perveen, N.; Aziz, A.

    1981-01-01

    Strontium 90, a most toxic among the beta emitting radionuclides, is found in the environment originating mostly from the global fallout from nuclear tests. Radioactive concentration of this radionuclide was measured in air-borne particulates, precipitation, surface water, seasonal vegetables and other items of diet. The report describes a radiochemical procedure for the separation of Y 90 by solvent extraction leading to the determination of Sr 90 content in the environmental and biological samples. The report also presents data on the concentration of Sr 90 in the biomedia at PINSTECH during 1979-80. The values of these concentrations are fairly comparable to those published in the current literature. (author)

  10. Strontium-90 and cesium-137 in soil (from May, 1982, to September, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in soil measured at 29 locations across Japan from May to September, 1982, are given in pCi/kg and mCi/km 2 , respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, the determination of stable strontium, calcium and potassium, and the counting are also described. Soil was collected in the spacious and flat area without past disturbance on the surface. Soil was taken from two layers of different depths, 0 to 5 cm and 5 to 20 cm. The sample solution was prepared and was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 6 to 1300 pCi/Kg for Sr-90 and 1 to 5000 pCi/Kg for Cs-137 in the sampling depth of 0 to 5 cm. (J.P.N.)

  11. Strontium-90 and cesium-137 in freshwater (from September, 1982, to December, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in fresh water measured at 4 locations across Japan from September to December, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. The sample was passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The sample solution prepared was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.08 to 0.22 pCi/l for Sr-90 and 0.003 to 0.020 pCi/l for Cs-137 in the freshwater. (J.P.N.)

  12. Strontium-90 and cesium-137 in sea water from July, 1981, to January, 1982

    International Nuclear Information System (INIS)

    1981-01-01

    Sea water was collected at fixed stations where the effect of terrestrial fresh water from rivers was expected to be negligibly small. Weather conditions were also considered, and the sampling was carried out after a few days in which rain did not fall. Attention was paid to avoid the contamination in sampling and storing. The sample was stored in 20 l polyethylene containers in the acidified state of pH lower than 3. 200 ml of sea water was also collected at the same stations for the determination of chlorinity. The radiochemical separation of strontium-90 and cesium-137 was performed, and the mounted precipitates were counted for activity using low background beta counters normally for 60 min. Net sample counting rates were corrected to obtain the content of strontium-90 and cesium-137 radioactivity per sample aliquot, and concentrations of these nuclides in the original sample were calculated. The maximum values obtained were 0.16 pCi/l of Sr-90 in Osaka-bay and 0.17 pCi/l of Cs-137 in Mutsu-bay in August, 1981. (Kako, I.)

  13. Strontium-90 and cesium-137 in service water (from June, 1982, to December, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in service water measured at 19 locations across Japan from June to December, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. Service water was collected at an intake of the water-treatment plant and at the tap. The sample was then passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The sample solution prepared was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.01 to 0.10 pCi/l for Sr-90 and 0.001 to 0.010 pCi/l for Cs-137 in the service water. (J.P.N.)

  14. Strontium-90 and cesium-137 in sea water (from July, 1982, to September, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in sea water collected at 11 locations across Japan from July to September, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. Sea water was collected at the fixed station where the effect of the terrestrial fresh water from rivers was negligibly small. The sampling was carried out when there was no rainfall for the last few days. The sample solution was prepared and was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.09 to 0.13 pCi/l for Sr-90 and 0.05 to 0.13 pCi/l for Cs-137 in the sea water. (Mori, K.)

  15. Solvent extraction method for rapid separation of strontium-90 in milk and food samples

    International Nuclear Information System (INIS)

    Hingorani, S.B.; Sathe, A.P.

    1991-01-01

    A solvent extraction method, using tributyl phosphate, for rapid separation of strontium-90 in milk and other food samples has been presented in this report in view of large number of samples recieved after Chernobyl accident for checking radioactive contamination. The earlier nitration method in use for the determination of 90 Sr through its daughter 90 Y takes over two weeks for analysis of a sample. While by this extraction method it takes only 4 to 5 hours for sample analysis. Complete estimation including initial counting can be done in a single day. The chemical recovery varies between 80-90% compared to nitration method which is 65-80%. The purity of the method has been established by following the decay of yttrium-90 separated. Some of the results obtained by adopting this chemical method for food analysis are included. The method is, thus, found to be rapid and convenient for accurate estimation of strontium-90 in milk and food samples. (author). 2 tabs., 1 fig

  16. Strontium-90 and cesium-137 in soil from May to July 1983

    International Nuclear Information System (INIS)

    1983-01-01

    The measured values in soil of strontium-90 and cesium-137 at a total of 4 locations throughout Japan from May to July, 1983 are given in pCi/kg and mCi/km 2 in the tables. The method of measurement is also described: collection and pretreatment of samples, preparation of the samples for analysis, separation of strontium-90 and cesium-137, determination of stable strontium, calcium and potassium, and counting. Soil was collected from the location in the spacious and flat area without any past disturbance. Soil was taken from two layers having different depths: 0--5 cm and 5--20 cm. The sample solution was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitates were counted for activity using a low background beta counter normally for 60 min. The maximum values were 690 pCi/kg for Sr-90 and 1300 pCi/kg for Cs-137, which were obtained from the samples in the 5-to-20 cm depth, in June 1983, at Akita-ken,Japan. (Mori, K.)

  17. Effect of Equilibrium Flow on Plasma Parameters

    International Nuclear Information System (INIS)

    Mukhopadhyay, S.; Lahiri, S.; Sakanaka, P.H.; Dasgupta, B.

    2003-01-01

    The transition to high confinement modes have been identified with the occurrence of strong shear flow near the plasma boundary. Plasma flow has also been associated with various instabilities, heating and other physical processes. As a result, it has become very important to study the effect of such flows on various plasma parameters. In this paper, we present the numerical solution of plasma equilibrium with incompressible toroidal and poloidal flows in several magnetic confinement configurations including tokamaks. The code, which was reported in the last conference, has been used to solve the problem in both circular and D-shaped devices. A parametric study on the generation of shear flow due to radial electric fields has been carried out. Through this study, it has been possible to generate plasma equilibria having sharp pressure gradients which are remarkably close to those reported in various H-mode experiments. The effects of flow on reverse shear equilibria and on the position of the magnetic axis has been studied. Finally, a detailed study has been carried out to understand the effect of flows on important plasma parameters, such as the poloidal flux function, β, energy confinement time

  18. Chronic exposure to low concentrations of strontium 90 affects bone physiology but not the hematopoietic system in mice.

    Science.gov (United States)

    Synhaeve, Nicholas; Wade-Gueye, Ndéye Marième; Musilli, Stefania; Stefani, Johanna; Grandcolas, Line; Gruel, Gaëtan; Souidi, Maâmar; Dublineau, Isabelle; Bertho, Jean-Marc

    2014-01-01

    The aim of this work was to delineate the effects of chronic ingestion of strontium 90 ((90) Sr) at low concentrations on the hematopoiesis and the bone physiology. A mouse model was used for that purpose. Parent animals ingested water containing 20 kBq l(-1) of (90) Sr two weeks before mating. Offspring were then continuously contaminated with (90) Sr through placental transfer during fetal life, through lactation after birth and through drinking water after weaning. At various ages between birth and 20 weeks, animals were tested for hematopoietic parameters such as blood cell counts, colony forming cells in spleen and bone marrow and cytokine concentrations in the plasma. However, we did not find any modification in (90) Sr ingesting animals as compared with control animals. By contrast, the analysis of bone physiology showed a modification of gene expression towards bone resorption. This was confirmed by an increase in C-telopeptide of collagen in the plasma of (90) Sr ingesting animals as compared with control animals. This modification in bone metabolism was not linked to a modification of the phosphocalcic homeostasis, as measured by calcium, phosphorus, vitamin D and parathyroid hormone in the blood. Overall these results suggest that the chronic ingestion of (90) Sr at low concentration in the long term may induce modifications in bone metabolism but not in hematopoiesis. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Model study of atmospheric transport using carbon 14 and strontium 90 as inert tracers

    Science.gov (United States)

    Kinnison, D. E.; Johnston, H. S.; Wuebbles, D. J.

    1994-10-01

    The observed excess carbon 14 in the atmosphere from 1963 to 1970 provides unique, but limited, data up to an altitude of about 35 km for testing the air motions calculated by 11 multidimensional atmospheric models. Strontium 90 measurements in the atmosphere from 1964 to mid-1967 provide data that have more latitude coverage than those of carbon 14 and are useful for testing combined models of air motions and aerosol settling. Model calculations for carbon 14 begin at October 1963, 9 months after the conclusion of the nuclear bomb tests; the initial conditions for the calculations are derived by three methods, each of which agrees fairly well with measured carbon 14 in October 1963 and each of which has widely different values in regions of the stratosphere where there were no carbon 14 measurements. The model results are compared to the stratospheric measurements, not as if the observed data were absolute standards, but in an effort to obtain new insight about the models and about the atmosphere. The measured carbon 14 vertical profiles at 31°N are qualitatively different from all of the models; the measured vertical profiles show a maximum mixing ratio in the altitude range of 20 to 25 km from October 1963 through July 1966, but all modeled profiles show mixing ratio maxima that increase in altitude from 20 km in October 1963 to greater than 40 km by April 1966. Both carbon 14 and strontium 90 data indicate that the models differ substantially among themselves with respect to stratosphere-troposphere exchange rate, but the modeled carbon 14 stratospheric residence times indicate that differences among the models are small with respect to transport rate between the middle stratosphere and the lower stratosphere. Strontium 90 data indicate that aerosol settling is important up to at least 35 km altitude. Relative to the measurements, about three quarters of the models transport carbon 14 from the lower stratosphere to the troposphere too rapidly, and all models

  20. Strontium 90 and cesium 137 content in the daily diet of two groups of people in Plovdiv

    International Nuclear Information System (INIS)

    Babakova, I.; Trendafilov, I.; Todorov, D.

    1975-01-01

    The contents of strontium 90 and cesium 137 in the daily diet of children, 7-11 years old, and teenagers, 14-18 years old, living under boarding house conditions is determined. The daily strontium 90 intake in the organism of children and teenagers amounts to 9,78 pCi, respectively 17,96 pCi and the daily intake of cesium 137 - to 13,21 pCi, respectively 21,33 pCi. The bigger part of the strontium 90 and cesium 137 intake comes from the bread, accounting for 4,85 pCi stroncium 90 and 5,08 to 7,0 pCi cesium 137. (author)

  1. The uptake of plutonium-239, 240, americium-241, strontium-90 into plants

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Johnson, T.E.

    1984-01-01

    This report describes the results of measurements on the uptake of plutonium, americium, strontium-90 and caesium-137 into peas, beet, oats, sweet corn, tomatoes and vegetable marrow grown in tubs containing radioactively-contaminated silts. The silts had been taken from an area of West Cumbria commonly referred to as the Ravenglass estuary. The experiments are categorised as being carried out under non-standard conditions because of the manner in which the radioactivity came to be incorporated into the growth medium. The growth medium was representative of conditions which could arise when the estuarine silt moves inland under the influence of wind and tide and mixes with the adjacent farm land. The silt had been contaminated by radioactive effluents from the nuclear fuels reprocessing plant at Sellafield and this contamination had been brought about by natural means. (Auth.)

  2. Strontium-90 and cesium-137 in freshwater (from Sept. 1983 to Dec. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Fresh water, 100 l each, was collected, and to which the carriers of strontium and cesium were added immediately after the sampling. The sample was vigorously stirred and filtered, and passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The eluate was used for radiochemical analysis. The chemical separation of strontium-90 and cesium-137 was carried out, and the chemical yields were determined. The precipitates were counted for the activity using low background beta counters normally for 60 min. The net sample counting rate was corrected for the counter efficiency, recovery, self-absorption and decay, to obtain the radioactivity per sample aliquot, and the concentrations of these nuclides in the original samples were calculated. The data at six sampling locations in Japan from September to December, 1983, on fresh water are reported. (Kako, I.)

  3. Location analysis and strontium-90 concentrations in deer antlers on the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Tiller, B L; Eberhardt, L E; Poston, T M

    1995-05-01

    The primary objective of this study was to examine the levels of strontium-90 ({sup 90}Sr) in deer antlers collected from near previously active reactor sites and distant from the reactor sites along that portion of the Columbia River which borders the Hanford Site. A second objective was to analyze the movements and home-ranges of mule deer residing within these areas and determine to what extent this information contributes to the observed {sup 90}Sr concentrations. {sup 90}Sr is a long-lived radionuclide (29.1 year half life) produced by fission in irradiated fuel in plutonium production reactors on the Hanford Site. It is also a major component of atmospheric fallout from weapons testing. Concentrations of radionuclides found in the developed environment onsite do not pose a health concern to humans or various wildlife routinely monitored. However, elevated levels of radionuclides in found biota may indicate routes of exposure requiring attention.

  4. Location analysis and strontium-90 concentrations in deer antlers on the Hanford Site

    International Nuclear Information System (INIS)

    Tiller, B.L.; Eberhardt, L.E.; Poston, T.M.

    1995-05-01

    The primary objective of this study was to examine the levels of strontium-90 ( 90 Sr) in deer antlers collected from near previously active reactor sites and distant from the reactor sites along that portion of the Columbia River which borders the Hanford Site. A second objective was to analyze the movements and home-ranges of mule deer residing within these areas and determine to what extent this information contributes to the observed 90 Sr concentrations. 90 Sr is a long-lived radionuclide (29.1 year half life) produced by fission in irradiated fuel in plutonium production reactors on the Hanford Site. It is also a major component of atmospheric fallout from weapons testing. Concentrations of radionuclides found in the developed environment onsite do not pose a health concern to humans or various wildlife routinely monitored. However, elevated levels of radionuclides in found biota may indicate routes of exposure requiring attention

  5. Behavior of strontium-90 and cesium-137 released into the pond of Office of Atomic Energy for Peace

    International Nuclear Information System (INIS)

    Milintawisamai, Mesak; Panyathipsakul, Yureeporn

    1989-01-01

    Strontium-90 and cesium-137 in liquid waste released from the waste disposal plant of Office of Atomic Energy for Peace(OAEP) have been followed since 1984. The concentration of both nuclides in surface water outside OAEP boundary is 2 to 30 times less than in the OAEP pond, the reservoir of liquid waste. This indicates that most of the nuclides are effectively absorbed by clay in the bottom of the pond. The nuclide concentration in fresh-water organisms in the pond such as fish, prawn and snail is also investigated to elucidate the behavior of strontium-90 and cesium-137 in a static fresh-water ecological system

  6. Simulating the Transfer of Strontium-90 from Soil to Leafy Vegetables by Using Strontium-88.

    Science.gov (United States)

    Kuke, Ding; Shujuan, Liu; Yingxue, He; Dong, Yan; Fengshou, Zhang; Shuifeng, Wang; Jinghua, Guo; Wei, Zhang; Xin, Wang; Xiaoyan, Jiang

    The transfer, from soil to Chinese cabbage and spinach, of radioactive strontium-90 released as a result of accidents in nuclear power stations was studied using a stable isotope of strontium, namely nuclide strontium-88 ( 88 Sr). The study led to an experimental model for assessing the hazard of radionuclide strontium-90 ( 90 Sr) entering the food chain and for predicting the risk to food safety. Chinese cabbage and spinach were grown in pots in a greenhouse and irrigated with deionized water containing known quantities of strontium. Based on the strontium content of that water, the plants were divided into five groups (treatments) and strontium content of the soil, and 30-day-old plants were determined by inductively coupled plasma atomic emission spectroscopy instrument (ICP-AES). Data on the strontium content of soil and plants enabled the development of a model using MATLAB, a mathematical software package, which included curve fitting and problem solving using regression equations and differential equations. Although strontium curves for leaves, stems, and roots of Chinese cabbage were not exactly the same, all showed a non-linear increase when compared with the increase in the content of strontium in soil. Strontium curves for leaves, stems, and roots of spinach were very similar and showed an initial increase followed by a decrease. Strontium concentrations in both Chinese cabbage and spinach were initially related to the concentrations of sodium and sulfur, the next two relevant nuclides being calcium and magnesium. The relationship between calcium and strontium in Chinese cabbage was different from that in spinach. By using 88 Sr to simulate the transfer of radionuclide 90 Sr from soil to a crop, the relevant data required to deal with accidental release of strontium can be obtained using a fitting curve and regression equations, thereby providing some experimental basis for evaluating the potential hazards posed by such accidents to the food chain.

  7. Two dimensional model study of atmospheric transport using carbon-14 and strontium-90 as inert tracers

    International Nuclear Information System (INIS)

    Kinnison, D.E.; Wuebbles, D.J.; Johnston, H.S.

    1992-02-01

    This study tests the transport processes in the LLNL two-dimensional chemical-radiative-transport model using recently reanalyzed carbon-14 and strontium-90 data. These radioactive tracers were produced bythe atmospheric nuclear bomb tests of 1952--58 and 1961--62, and they were measured at a few latitudes up to 35 kilometers over the period 1955--1970. Selected horizontal and vertical eddy diffusion coefficients were varied in the model to test their sensitivity to short and long term transpose of carbon-14. A sharp transition of K zz and K yy through the tropopause, as opposed to a slow transition between the same limiting values, shows a distinct improvement in the calculated carbon-14 distributions, a distinct improvement in the calculated seasonal and latitudinal distribution of ozone columns (relative to TOMS observations), and a very large difference in the calculated ozone reduction by a possible fleet of High Speed Civil Transports. Calculated northern hemisphere carbon-14 is more sensitive to variation of K yy than are global ozone columns. Strontium-90 was used to test the LLNL tropopause height at four different latitudes. Starting with the 1960 background distribution of carbon-14, we calculate the input of carbon-14 as the sum of each nuclear test of the 1961--62 series, using two bomb-cloud rise models. With the Seitz bomb-rise formulation in the LLNL model, we find good agreement between calculated and observedcarbon-14 (with noticeable exceptions at the north polar tropopause and the short-term mid-latitude mid-stratosphere) between 1963 and 1970

  8. Attempt to evaluate the cumulative deposit of strontium 90 in several French centres; Essai d'evaluation du depot cumulatif de strontium 90 dans plusieurs stations francaises

    Energy Technology Data Exchange (ETDEWEB)

    Garnier, A [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    In order to be able to interpret results of radioactivity controls of the ambient atmosphere and of the supply chain carried out in several French centres, it is necessary to know the value of the cumulative strontium-90 deposit resulting from fall-out. The estimation of the fall-out which occurred locally in the years before systematic controls were established can be made by assuming that the {sup 90}Sr concentration in rain varies little from one place to another (if they are fairly close) and that the deposit can be deduced from that measured in a single station by making corrections for differences in the rainfall. This assumption is confirmed by applying the method to the calculation of {sup 90}Sr fall-out at Ispra, Mol and at several French centres: the values calculated are compared to those obtained by measurements carried out since 1958 in some cases, and since 1960 in others. The results show that the method is valid for calculating fall-out prior to 1960 (in the absence of information) and to deduce with sufficient approximation the subsequent cumulative deposits in the French centres under consideration. (author) [French] L'evaluation du depot cumulatif de Sr 90 consecutif aux retombees est necessaire a l'interpretation des resultats du controle de la radioactivite du milieu ambiant et de la cha e alimentaire effectue en plusieurs stations francaises. L'estimation des retombees locale des annees anterieures a la mise en oeuvre systematique des moyens de surveillance peut etre faite en admettant que la concentration de Sr 90 dans la pluie varie peu d'un endroit a l'autre (dans des regions assez rapprochees) et que le depot peut etre deduit de celui mesure en une station gr e a des corrections tenant compte de la variation de pluviosite. Cette hypothese est verifiee en appliquant la methode au calcul des retombees de Sr 90 a Ispra, a Mol, et en plusieurs stations francaises: les valeurs calculees sont comparees a celles obtenues par les mesures

  9. Evaluation of field sampling and preservation methods for strontium-90 in ground water at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Cecil, L.D.; Knobel, L.L.; Wegner, S.J.; Moore, L.L.

    1989-01-01

    Water from four wells completed in the Snake River Plain aquifer was sampled as part of the US Geological Survey's quality assurance program to evaluate the effect of filtration and preservation methods on strontium-90 concentrations in groundwater at the Idaho National Engineering Laboratory. Water from each well was filtered through either a 0.45-micrometer membrane or a 0.1-micrometer membrane filter; unfiltered samples also were collected. Two sets of filtered and two sets of unfiltered samples was preserved in the field with reagent-grade hydrochloric acid and the other set of samples was not acidified. For water from wells with strontium-90 concentrations at or above the reporting level, 94% or more of the strontium-90 is in true solution or in colloidal particles smaller than 0.1 micrometer. These results suggest that within-laboratory reproducibility for strontium-90 in groundwater at the INEL is not significantly affected by changes in filtration and preservation methods used for sample collections. 13 refs., 2 figs., 6 tabs

  10. Variability of the strontium-90 and caesium-137 burden of native plants and animals

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, L L

    1946-10-17

    Cesium-137 and /sup 90/Sr body burdens were determined in plants and animals at selected sites in Alaska, Idaho, Nevada, Utah, California, and Maryland, and coefficients of variations were derived. Coefficients of variation for burdens of /sup 90/Sr and /sup 137/Cs were suprisingly consistent over a wide range of plants and animals. Values for /sup 90/Sr ranged from about 0.30 to 0.45 while those for /sup 137/Cs appeared somewhat lower, ranging roughly from 0.25 to 0.35. Various factors possibly affecting individual sets of data were indicated. With one exception (Maryland white-tailed deer), the bone-strontium-90 values were calculated in terms of picocuries (10/sup -12/c) per g calcium (strontium units). Analysis of the Alaskan caribou data in terms of picocuries per g standard dry weight yields virtually the same coefficient of variation. The plant data were calculated on the standard dry weight basis, while soil-levels were on a unit area basis. All /sup 137/Cs values were expressed in units per g dry weight. Results reported here should not be interpreted as meaning that the coefficient of variation for levels of these two radionuclides is everywhere roughly constant.

  11. Strontium-90 and cesium-137 in soil (from May 1985 to Jul. 1985)

    International Nuclear Information System (INIS)

    1985-01-01

    This report is aimed at listing measurements of strontium-90 and cesium-137 in soil made at eight places across Japan during the period from May to July in 1985. Collection and pretreatment methods are described for samples of rain and dry fallout, airborne dust, service water and freshwater, soil, sea water, sea sediments, total diet, rice, milk, vegetables, tea, as well as fish, shellfish and seaweeds. The methods for the preparation of these samples for analysis are also outlined. Sample solutions were neutralized with sodium hydroxide, and the precipitate of strontium and calcium carbonates was separated after sodium carbonate was added. The supernatant solution was retained for cesium-137 determination. After being precipitated as oxalates, strontium and calcium were separated by successive fuming nitric acid separations. For the determination of stable strontium, calcium and potassium, soil and sediment were treated with sodium hydroxide and hydrochloric acid for extraction while other samples were ashed and digested. Calcium, separated as oxalate, was determined by titration while stable strontium and potassium were determined by atomic absorption and flame emission spectroscopy, respectively. Couting for activity was carried out using low background beta counters normally for 60 min. (Nogami, K.)

  12. Strontium-90 and cesium-137 in service water from June to December, 1981

    International Nuclear Information System (INIS)

    1981-01-01

    Service water, 100 l each, was collected at an intake of a water treatment plant and at a tap after water was left running for five minutes. The carriers of strontium and cesium were added to water immediately after sampling, and the sample was vigorously stirred and filtered. Then it was passed through a cation exchange column at a rate of 80 ml/min. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column, and separated. After the radiochemical separation, the mounted precipitates were counted for activity using low background beta counters normally for 60 min. Net sample counting rates were corrected for counter efficiency, recovery, self absorption and decay to obtain the content of strontium-90 and cesium-137 radioactivity per sample aliquot. From the results, concentrations of these nuclides in the original sample were calculated. The maximum values obtained were 0.29 pCi/l of Sr-90 in Kyoto in August, 1981, and 0.02 pCi/l of Cs-137 in Kyoto in August and in Inuyama in December, 1981, in case of source water. In case of tap water, they were 0.18 pCi/l of Sr-90 in Kobe in December, 1981, and 0.02 pCi/l of Cs-137 in Kyoto in August, 1981. (Kako, I.)

  13. Strontium-90 and cesium-137 in service water from December, 1981, to July, 1982

    International Nuclear Information System (INIS)

    1982-01-01

    Service water, 100 liters each, was collected at an intake of a water-treatment plant and at a tap after water was left running for five minutes. Water, to which the carriers of strontium and cesium were added immediately after sampling, was vigorously stirred and filtered. The sample was then passed through a cation exchange column. After radiochemical separation, the precipitates were counted for the activity using a low-background beta counter, normally for 60 min. The measuring techniques are first described; i.e. the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting. The measured results are given in a table for the following locations: source water - Tokyo, Osaka, Hokkaido, Kyoto, Kanagawa, Aichi, Fukuoka; tap water - Hokkaido, Akita, Fukushima, Tokyo, Fukui, Shizuoka, Shimane, Okayama, Fukuoka, Saga, Nagasaki, Kyoto, Wakayama, Okinawa, Hiroshima, Aomori, Yamagata, Ibaraki, Kanagawa, Niigata, Ishikawa, Nagano, Aichi, Osaka, Hyogo, Tottori, Yamaguchi, Ehime, Kochi, Kagoshima. (Mori, K.)

  14. An unexpected rise in strontium-90 in US deciduous teeth in the 1990s

    International Nuclear Information System (INIS)

    Mangano, Joseph J.; Gould, Jay M.; Sternglass, Ernest J.; Sherman, Janette D.; McDonnell, William

    2003-01-01

    For several decades, the United States has been without an ongoing program measuring levels of fission products in the body. Strontium-90 (Sr-90) concentrations in 2089 deciduous (baby) teeth, mostly from persons living near nuclear power reactors, reveal that average levels rose 48.5% for persons born in the late 1990s compared to those born in the late 1980s. This trend represents the first sustained increase since the early 1960s, before atmospheric weapons tests were banned. The trend was consistent for each of the five states for which at least 130 teeth are available. The highest averages were found in southeastern Pennsylvania, and the lowest in California (San Francisco and Sacramento), neither of which is near an operating nuclear reactor. In each state studied, the average Sr-90 concentration is highest in counties situated closest to nuclear reactors. It is likely that, 40 years after large-scale atmospheric atomic bomb tests ended, much of the current in-body radioactivity represents nuclear reactor emissions

  15. Implementation of a permeable reactive barrier for treatment of groundwater impacted by strontium-90

    International Nuclear Information System (INIS)

    Przepiora, A.; Bodine, D.; Dollar, P.; Smith, P.

    2014-01-01

    A funnel and gate permeable reactive barrier (PRB) system was constructed to treat strontium-90 (Sr- 90) in groundwater migrating from a legacy waste disposal area into an adjacent wetland. The PRB system was designed to contain and direct the Sr-90 impacted groundwater into treatment 'gates' containing zeolite using a low permeability 'funnel' sections constructed with soil-bentonite slurry. The constructed PRB met all dimension and permeability specifications. Initial performance monitoring results indicate that the PRB captured the Sr-90 impacted groundwater plume and the beta radiation values in groundwater emerging from the treatment gates ranged from 35 to 86 Becquerel's per litre (Bq/L), equivalent to a reduction by 88% to 99% from the influent values. Those initial performance results were influenced by residual impacts present in the aquifer material prior to PRB installation. It is anticipated that the clean-up target of 5 Bq/L will be achieved with time as treated groundwater emerging from the PRB flushes through the downgradient aquifer zone. (author)

  16. Accelerator mass spectrometry of Strontium-90 for homeland security, environmental monitoring, and human health

    Energy Technology Data Exchange (ETDEWEB)

    Tumey, S J; Brown, T A; Hamilton, T F; Hillegonds, D J

    2008-03-03

    Strontium-90 is one of the most hazardous materials managed by agencies charged with protecting the public from radiation. Traditional radiometric methods have been limited by low sample throughput and slow turnaround times. Mass spectrometry offers the advantage of shorter analysis times and the ability to measure samples immediately after processing, however conventional mass spectrometric techniques are susceptible to molecular isobaric interferences that limit their overall sensitivity. In contrast, accelerator mass spectrometry is insensitive to molecular interferences and we have therefore begun developing a method for determination of {sup 90}Sr by accelerator mass spectrometry. Despite a pervasive interference from {sup 90}Zr, our initial development has yielded an instrumental background of {approx} 10{sup 8} atoms (75 mBq) per sample. Further refinement of our system (e.g., redesign of our detector, use of alternative target materials) is expected to push the background below 10{sup 6} atoms, close to the theoretical limit for AMS. Once we have refined our system and developed suitable sample preparation protocols, we will utilize our capability in applications to homeland security, environmental monitoring, and human health.

  17. Strontium-90 and cesium-137 in sea sediments from July, 1981, to January, 1982

    International Nuclear Information System (INIS)

    1981-01-01

    Sediment was collected in the same area as that of sea water sampling, taking the following criteria into account: the depth of water exceeds 1 m at low tide, no significant sedimental movement is observed in the vicinity of concern, mud, silt and fine sand are preferable. A conventional sediment sampling device was used for collecting a top few cm of surface sediment. Approximately 4 kg of the sample in wet weight was spread on a large porcelain dish and dried in an electric oven to a constant weight. After removal of pebbles, shells and other foreign matters, the sediment sample was dried in a hot air oven, and ground finely with a mortar. The sample was passed through a 20 mesh sieve, and heated in the presence of strontium and cesium carriers with sodium hydroxide. Then it was heated with hydrochloric acid, and the radiochemical separation of strontium-90 and cesium-137 was performed. The mounted precipitates were counted for activity, and after the correction of net counting rates, concentrations of these nuclides were calculated. The maximum values obtained were 22 pCi/kg of Sr-90 and 220 pCi/kg of Sc-137 in Mutsu-bay in August, 1981. (Kako, I.)

  18. Strontium-90 concentrations in pronghorn antelope bones near a nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Markham, O.D.; Halford, D.K.

    1980-01-01

    Metacarpal bones were collected from pronghorn antelope near a nuclear fuel reprocessing plant and adjacent areas on the Idaho National Engineering Laboratory (INEL) Site in Southeastern Idaho. Control bones were collected from offsite animals at higher elevations. Average concentrations in metacarpals were 9.6+-2.8(SE) pCi/g(ash) within 10 km of the Idaho Chemical Processing Plant (ICPP), 4.0+-0.9pCi/g for animals on the remainder of the INEL Site and 5.5+-1.0pCi/g for control animals. ICPP atmospheric releases of 90 Sr appeared to have caused a significant (P 90 Sr concentrations in antelope bones within 10 km of the ICPP as compared to bones of other INEL antelope. However, the ICPP antelope bone 90 Sr concentrations were not statistically different from that occurring in bones of the control animals from higher elevations. Antelope near the ICPP received approximately double the radiation dose to bone compared to doses received by other INEL antelope as a result of 90 Sr in bone. Strontium-90 in bone from both fallout and ICPP sources resulted in an estimated average radiation dose of 40 mrad/yr to edosteal cells and 20 mrad/yr to active bone marrow. (author)

  19. Parameter Estimation for a Computable General Equilibrium Model

    DEFF Research Database (Denmark)

    Arndt, Channing; Robinson, Sherman; Tarp, Finn

    2002-01-01

    We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of non-linear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...

  20. Parameter Estimation for a Computable General Equilibrium Model

    DEFF Research Database (Denmark)

    Arndt, Channing; Robinson, Sherman; Tarp, Finn

    We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of nonlinear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...

  1. Postoperative Strontium-90 Brachytherapy in the Prevention of Keloids: Results and Prognostic Factors

    International Nuclear Information System (INIS)

    Viani, Gustavo A.; Stefano, Eduardo J.; Afonso, Sergio L.; De Fendi, Ligia I.

    2009-01-01

    Purpose: The aim of this study was to evaluate the results of keloidectomy and strontium 90 brachytherapy in the prevention of keloid recurrence following excision and to identify outcome and the prognostic factors that predict keloid recurrence after irradiation. Methods and Materials: Data of 612 patients with 892 keloids treated between 1992 and 2006 were evaluated retrospectively. Brachytherapy was performed using a Sr-90Y surface applicator. Total dose was 20 Gy in 10 fractions. Results: With a median follow-up of 61 months, the overall recurrence-free response rate for all keloids was 87.6%. Multivariate analysis revealed the following prognostic factors for recurrence: keloid size > 5 cm (p < 0.0001), burn scars as the keloid etiology (p < 0.0001), and previous treatment (p < 0.0001). Outcome was not found to be significantly related to the interval between surgery and radiotherapy, sex, or age. Pruritus and skin reddening were the most common symptoms of keloids, but all signs and symptoms abated with time after treatment. Cosmetic results from the keloid treatment were considered good or excellent in 70.6% of the patients. Conclusion: Our study findings show that excision plus Sr-90 brachytherapy is effective in the eradication of keloids. Sr-90 radiotherapy (20 Gy in 10 fractions) achieved a similar local control rate, as have higher doses per fraction in other series. It also resulted in a good cosmetic rate and relief of symptoms. Our data further suggest that the initiation of postoperative irradiation within hours of surgical excision is not important to therapeutic outcome.

  2. Multiple limbal haemangiosarcomas in a border collie dog: management by lamellar keratectomy/sclerectomy and strontium-90 beta plesiotherapy.

    Science.gov (United States)

    Donaldson, D; Sansom, J; Murphy, S; Scase, T

    2006-09-01

    An eight-year-old, neutered, male border collie dog was presented with a six-week history of left ocular discomfort and a raised, red mass at the lateral limbus. The right eye had been enucleated approximately 12 months previously following suspected trauma when the eye had become red and painful. The mass was excised using superficial keratectomy/sclerectomy and the surgery site was treated with strontium-90 beta radiation. Histopathological findings were consistent with a diagnosis of haemangiosarcoma. Immunohistochemical staining showed uniform expression of CD31 in neoplastic cells, confirming their endothelial origin. Two further treatments with strontium-90 beta radiation were applied to the surgical site at weekly intervals. Twenty-six weeks after surgery, a second, raised, red limbal mass became apparent at the medial limbus of the left eye. Surgical excision and adjuvant strontium-90 beta plesiotherapy were performed as described for the initial tumour. Routine histopathological analysis confirmed haemangiosarcoma at this site. Eighty-six weeks following the initial presentation, no recurrence of ocular haemangiosarcoma was evident.

  3. Production of Strontium-90 Thermal Power Sources; Fabrication de sources d'energie thermique au strontium-90; Proizvodstvo istochnikov ''teplovoj ehnergii iz Sr''9''0; Preparacion de fuentes de energia termica con estroncio-90

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, J. S.; Bloom, J. L.; Schneider, A. [Martin Company, Nuclear Division, Baltimore 3, MD (United States)

    1963-11-15

    One of the most attractive fields for utilization of large quantities of waste fission products is the field of direct-conversion power supplies for remote locations. Strontium-90 is being given the greatest exploitation because of its availability, nuclear properties, and the relative ease with which it can be fabricated into compact heat sources. Strontium-90 fuelled generators are being used to power automatic weather stations and navigational aids, and consideration is being given to the use of strontium-90 as a power source for space vehicles. Evaluation of several potentially useful strontium compounds led to the selection of the titanate as exhibiting overall properties most desirable for this purpose. Strontium-90, separated from crude fission product streams and purified to the requisite degree by the USAEC's Hanford Works, is shipped in the form of the carbonate to a hot cell facility operated by the Martin Company, where it is converted to titanate pellets. This process is an adaption to remote operation of conventional chemical and ceramic techniques. The pellets are encapsulated in Hastelloy C containers for use in thermoelectric power supplies. Unusual operational problems are encountered because the large quantities of strontium-90 handled (potentially millions of curies per year) represent formidable radiation and contamination hazards. Details of the facility, equipment, process, and safety criteria are given. The operational experience gained during the recent processing of the first 250 000 curies of strontium-90 into fuel for a SNAP-7 generator is described. Encapsulation, calorimetry, decontamination, and waste disposal procedures are also outlined. (author) [French] L'une des utilisations les plus interessantes des produits de fission en grande quantite consiste a les employer comme sources d'energie par combustion directe pour des installations geographiquement isolees. C'est le strontium-90 qui est l e plus utilise parce qu'on en dispose en

  4. Water purification from cesium-137 and strontium-90 using natural and activated laminar and laminar-band silicates

    International Nuclear Information System (INIS)

    Kornilovich, B.Yu.; Pshinko, G.N.; Kosorukov, A.A.; Mas'ko, A.N.; Spasenova, L.N.; Dregval', T.N.

    1991-01-01

    Cesium-137 and strontium-90 radionuclides are studied for the process of their sorption from natural waters by basic representatives of disperse silicates: kaolinites of Glukhovetskoe and Glukhovskoe deposits (Ukraine), montmorillonites of the Cherkassy (Ukraine) and Oglanlin (Turkmenia) deposits, palygorskite and natural mixture of montmorillonite and palygorskite of the Cherkassy deposit. The best sorption properties are revealed for laminated silicates with a swelling structure (montmorillonites) and high-dispersive laminar-band silicates (palygorskite). It proved possible to improve sorption properties of silicate minerals for radionuclides by means of their mechanochemical activation

  5. Application of TREECS Modeling System to Strontium-90 for Borschi Watershed near Chernobyl, Ukraine

    International Nuclear Information System (INIS)

    Johnson, Billy E.; Dortch, Mark S.

    2014-01-01

    The Training Range Environmental Evaluation and Characterization System (TREECS™) ( (http://el.erdc.usace.army.mil/treecs/)) is being developed by the U.S. Army Engineer Research and Development Center (ERDC) for the U.S. Army to forecast the fate of munitions constituents (MC) (such as high explosives (HE) and metals) found on firing/training ranges, as well as those subsequently transported to surface water and groundwater. The overall purpose of TREECS™ is to provide environmental specialists with tools to assess the potential for MC migration into surface water and groundwater systems and to assess range management strategies to ensure protection of human health and the environment. The multimedia fate/transport models within TREECS™ are mathematical models of reduced form (e.g., reduced dimensionality) that allow rapid application with less input data requirements compared with more complicated models. Although TREECS™ was developed for the fate of MC from military ranges, it has general applicability to many other situations requiring prediction of contaminant (including radionuclide) fate in multi-media environmental systems. TREECS™ was applied to the Borschi watershed near the Chernobyl Nuclear Power Plant, Ukraine. At this site, TREECS™ demonstrated its use as a modeling tool to predict the fate of strontium 90 ( 90 Sr). The most sensitive and uncertain input for this application was the soil-water partitioning distribution coefficient (K d ) for 90 Sr. The TREECS™ soil model provided reasonable estimates of the surface water export flux of 90 Sr from the Borschi watershed when using a K d for 90 Sr of 200 L/kg. The computed export for the year 2000 was 0.18% of the watershed inventory of 90 Sr compared to the estimated export flux of 0.14% based on field data collected during 1999–2001. The model indicated that assumptions regarding the form of the inventory, whether dissolved or in solid phase form, did not appreciably affect export

  6. Inference of directional selection and mutation parameters assuming equilibrium.

    Science.gov (United States)

    Vogl, Claus; Bergman, Juraj

    2015-12-01

    In a classical study, Wright (1931) proposed a model for the evolution of a biallelic locus under the influence of mutation, directional selection and drift. He derived the equilibrium distribution of the allelic proportion conditional on the scaled mutation rate, the mutation bias and the scaled strength of directional selection. The equilibrium distribution can be used for inference of these parameters with genome-wide datasets of "site frequency spectra" (SFS). Assuming that the scaled mutation rate is low, Wright's model can be approximated by a boundary-mutation model, where mutations are introduced into the population exclusively from sites fixed for the preferred or unpreferred allelic states. With the boundary-mutation model, inference can be partitioned: (i) the shape of the SFS distribution within the polymorphic region is determined by random drift and directional selection, but not by the mutation parameters, such that inference of the selection parameter relies exclusively on the polymorphic sites in the SFS; (ii) the mutation parameters can be inferred from the amount of polymorphic and monomorphic preferred and unpreferred alleles, conditional on the selection parameter. Herein, we derive maximum likelihood estimators for the mutation and selection parameters in equilibrium and apply the method to simulated SFS data as well as empirical data from a Madagascar population of Drosophila simulans. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Influence of various room parameters upon radon daughter equilibrium indoors

    International Nuclear Information System (INIS)

    Islam, G.S.; Mazumdar, S.C.; Ashraf, M.A.

    1995-06-01

    The parameters such as ventilation rate, attachment rate to aerosols and deposition processes, which influence the radon daughter equilibrium indoors, are discussed and the validity of the theoretical model checked by experiments. In agreement with the model calculations, the experimental data show, that the equilibrium factor F in rooms is mainly influenced by the rate of attachment to aerosols and the plateout of radon daughters. The equilibrium factor varies between 0.3 and 0.4 at an attachment rate of 300 h -1 . The influence of ventilation upon the free fraction of RaA( 218 Pp)-atoms is also investigated. This is in good agreement with the results of the measurements carried out in different types of rooms at the University Campus of Rajshahi. (author). 20 refs, 3 figs, 3 tabs

  8. A method for external measurement of toroidal equilibrium parameters

    International Nuclear Information System (INIS)

    Brunsell, P.; Hellblom, G.; Brynolf, J.

    1992-01-01

    A method has been developed for determining from external magnetic field measurements the horizontal shift, the vertical shift and the poloidal field asymmetry parameter (Λ) of a toroidal plasma in force equilibrium. The magnetic measurements consist of two toroidal differential flux loops, giving the average vertical magnetic field and the average radial magnetic field respectively, together with cosine-coils for obtaining the m=1 cosine harmonic of the external poloidal magnetic field component. The method is used to analyse the evolution of the toroidal equilibrium during reversed-field pinch discharges in the Extrap T1-U device. We find that good equilibrium control is needed for long plasma pulses. For non-optimized externally applied vertical fields, the diagnostic clearly shows a horizontal drift motion of the pinch resulting in earlier discharge termination. (au)

  9. Cost benefit analysis of remediation alternatives for controlling the flux of strontium-90 into the Columbia River

    International Nuclear Information System (INIS)

    Gustafson, F.W.; Todd, M.E.

    1993-09-01

    The release of large volumes of water to waste disposal cribs at the Hanford Site's 100-N Area caused contaminants, principally strontium-90, to be carried toward the Columbia River through the groundwater. Since shutdown of the N Reactor, these releases have been discontinued, although small water flows continue to be discharged to the 1325-N crib. Most of the contamination which is now transported to the river is occurring as a result of the natural groundwater movement. The contaminated groundwater at N Springs flows into the river through seeps and springs along the river's edge. An expedited response action (ERA) has been proposed to eliminate or restrict the flux of strontium-90 into the river. A cost benefit analysis of potential remedial alternatives was completed that recommends the alternative which best meets given selection criteria prescribed by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The methodology used for evaluation, cost analysis, and alternative recommendation is the engineering evaluation/cost analysis (EE/CA). Complete remediation of the contaminated groundwater beneath 100-N Area was not a principal objective of the analysis. The objective of the cost benefit analysis was to identify a remedial alternative that optimizes the degree of benefit produced for the costs incurred

  10. Derivation of strontium-90 and cesium-137 residual radioactive material guidelines for the Laboratory for Energy-Related Health Research, University of California, Davis

    International Nuclear Information System (INIS)

    Nimmagadda, M.; Yu, C.

    1993-04-01

    Residual radioactive material guidelines for strontium-90 and cesium-137 were derived for the Laboratory for Energy-Related Health Research (LEHR) site in Davis, California. The guideline derivation was based on a dose limit of 100 mrem/yr. The US Department of Energy (DOE) residual radioactive material guideline computer code, RESRAD, was used in this evaluation; this code implements the methodology described in the DOE manual for implementing residual radioactive material guidelines. Three potential site utilization scenarios were considered with the assumption that, for a period of 1,000 years following remedial action, the site will be utilized without radiological restrictions. The defined scenarios vary with regard to use of the site, time spent at the site, and sources of food consumed. The results of the evaluation indicate that the basic dose limit of 100 mrem/yr will not be exceeded within 1,000 years for either strontium-90 or cesium-137, provided that the soil concentrations of these radionuclides at the LEHR site do not exceed the following levels: 71,000 pCi/g for strontium-90 and 91 pCi/g for cesium-137 for Scenario A (researcher: the expected scenario); 160,000 pCi/g for strontium-90 and 220 pCi/g for cesium-137 for Scenario B (recreationist: a plausible scenario); and 37 pCi/g for strontium-90 and 32 pCi/g for cesium-137 for Scenario C (resident farmer ingesting food produced in the contaminated area: a plausible scenario). The derived guidelines are single-radionuclide guidelines and are linearly proportional to the dose limit used in the calculations. In setting the actual strontium-90 and cesium-137 guidelines for the LEHR site, DOE will apply the as low as reasonably achievable (ALARA) policy to the decision-making process, along with other factors such as whether a particular scenario is reasonable and appropriate

  11. The sequential separation of strontium-90, yttrium-90, promethium-147, and cerium-144 from urine and their subsequent estimation

    International Nuclear Information System (INIS)

    Kramer, G.H.; Davies, J.M.

    1981-04-01

    A method has been developed for separating low-level activities of the beta-emitting isotopes strontium-90, yttrium-90, promethium-147 and cerium-144 from urine and aqueous solutions. They are subsequently estimated by planchet or liquid scintillation counting. The radionuclides are separated from each other and from interfering elements by solvent extraction with HDEHP (di-2-ethylhexyl phosphoric acid) in n-heptane. It is possible to separate the elements with a minimum of cross-contamination by selecting appropriate pH's and solvent concentrations. Percentage recoveries for the radionuclides are: 90 Sr, 100 +- 12; 90 Y, 65 +- 4; 147 Pm, 90 +- 8; 144 Ce, 87 +- 11. The limits of detection are: 90 Sr, 0.6 pCi; 90 Y, 0.7 pCi; 147 Pm, 1.0 pCi; 144 Ce, 0.8 pCi. (author)

  12. Use of strontium-90 beta irradiation as an adjunctive therapy for the management of squamous cell carcinoma of the conjunctiva

    International Nuclear Information System (INIS)

    Nisa, L.; Momta, S.; Jehan, A.H.; Rahman, M.U.

    2005-01-01

    Full text: To evaluate the effectiveness of strontium-90 beta irradiation in management of squamous cell carcinoma of the conjunctiva. A retrospective analysis of the medical records of 5 patients treated with strontium-90 beta irradiation was done. Squamous cell carcinoma of the conjunctiva was histologically proved in all patients who had initial surgery to remove the major part of the lesion. This was followed by beta radiation within 48 hours with Sr -90 contact applicator obtained from Amersham International. The hand held Sr- 90 eye applicator was used after appropriately instilling the eyes with local anesthetics and a total of 5000cGy was delivered in seven fractions. Follow-up period was from 6 to 12 months. Clinical response and side effects to the therapy were used as outcome measurements. Three patients showed good response with no evidence of tumor within 6 to 12 months of the follow-up period. One patient was lost to follow-up and one patient showed local recurrence within 4 months. In this patient the tumor was more extensive involving the limbal conjunctiva and the cornea. The early side effects of beta radiation reported by all five patients were temporary local irritation of the eyes with additional mild chemosis in four patients. None of the other three potentially cured patients showed any long-term adverse reactions. There were no incidence of late radiation induced complications such as corneal ulcerations, damage to cornea, eye pain, cataract or any other serious effects in these patients within the follow-up period. In conclusion, beta irradiation is an effective post-surgical therapy for local control of superficial conjunctival squamous cell carcinoma. The very low and minimum side -effects of Sr-90 irradiation is an advantage, which makes it a good alternative to external beam radiation, which has serious side effects. (author)

  13. Human Internal Contamination with Strontium-90 Titanate; Contamination Interne du Corps Humain par le Titanate de Strontium 90; 0412 041d 0414 ; Contaminacion Interna del Cuerpo Humano con Titanato de Estroncio-90

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, F. J.; Wald, N.; Wechsler, R. L. [Graduate School of Public Health and School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States)

    1964-11-15

    Strontium-90 has been used in multikilocurie quantities recently as a heat source for thermoelectric generators. The titanate was carefully selected for this purpose as the chemical form which best met requirements including inertness to corrosive attack in the event of accidental release to the environment. An industrial accidental exposure of one worker on 26 June 1963 to strontium-90 titanate powder, originally in the form of particles of about 120 {mu}m and less, provided an opportunity to attempt the assessment of the human body burden of this supposedly highly insoluble compound. Because of the physical and biological behaviour of the particles, it was assumed that the actual particle size which was dispersed and ingested and/or inhaled by the exposed person was in the range of 1 to 30 {mu}m. Three techniques were used to estimate the body burden. Whole-body radiation counting carried out by Dr. Charles H. Miller at Argonne National Laboratory, which only gave an upper limit because of the non-specific Bremsstrahlung spectrum from strontium-90, yttrium-90 indicated an initial total-body burden of 4.8 {mu}c. The second method, total urinary and faecal output collection, totalled 5.0 for the first 20 d. Combining that amount with an estimate of the amount retained in the body, an initial total-body burden of 5.2 {mu}c was obtained. The third technique, blood radioactivity determination, indicated an initial total-body burden of 6 {mu}c. The ratio of faecal to urinary output in the first 20 d was 15 to 1, and 94% of the total strontium-90 excretion was via the gastro-intestinal tract. It is of interest, however, that a significant fraction was evidently soluble. By the 20th post-incident day, it was estimated that the retained body burden was only 5% of the total intake. Methods used in that period to enhance faecal excretion by MgSO{sub 4} and urinary excretion by a combination of Ca-gluconate and NH{sub 4}CI are described. Subsequent excretion patterns and the

  14. Technetium-99 and strontium-90: Abundance determination at ultratrace sensitivity by AMS as signatures of undeclared nuclear reprocessing activity

    International Nuclear Information System (INIS)

    McAninch, J.E.; Proctor, I.D.

    1995-03-01

    The purpose of this White Paper is to examine the use of the ultratrace technique Accelerator Mass Spectrometry (AMS) to lower detection limits for 99 Tc and 90 Sr, and to examine the utility of these isotopes as signatures of a convert reprocessing facility. The International Atomic Energy Agency (IAEA) has committed to improving the effectiveness of the IAEA Safeguards System. This is in some degree a result of the discovery in 1991 of an undeclared Iraqi EMIS program. Recommendations from the March 1993 Consultants Group Meeting have resulted in several studies and follow on field trials to identify environmental signatures from covert nuclear fuel reprocessing activity. In particular, the April, 1993 reports of the Standing Advisory Group on Safeguards Implementation (SAGSI) identified the long-lived radioisotopes Technetium-99 and strontium-90 as two reliable signatures of fuel reprocessing activity. This report also suggested pathways in the chemical processing of irradiated fuel where these elements would be volatilized and potentially released in amounts detectable with ultratrace sensitivity techniques. Based on measured 99 Tc background levels compiled from a variety of sources, it is estimated that AMS can provide 10% measurements of environmental levels of 99 Tc in a few minutes using modestly sized samples: a few grams for soils, plants, or animal tissues; one to several liters for rain or seawater samples; and tens to hundreds of cubic meters for air sampling. Small sample sizes and high sample throughput result in significant increases in feasibility, cost effectiveness, and quality of data for a regional monitoring program. Similar results are expected for 90 Sr

  15. Determination of toroidal equilibrium parameters from magnetic probe measurements

    International Nuclear Information System (INIS)

    Brynolf, J.; Eriksson, H.G.; Persson, H.; Hellblom, G.

    1992-12-01

    A method has been developed by which the poloidal flux function in the vacuum region between the plasma and the external conductors (and the iron core) can be deduced from external magnetic field measurements. The plasma is in equilibrium and the solution is restricted to plasmas without irregularities. The poloidal field components Bθ and B r are measured at different poloidal positions outside the liner and modelled by truncated Fourier series. The Grad-Shafranov equation in the vacuum region is then solved with these modelled values of Bθ and B r as boundary conditions. (authors)

  16. Investigation report of the release of strontium-90 from the Building 3517 Cell Ventilation Improvements construction site on November 29, 1985

    International Nuclear Information System (INIS)

    1986-01-01

    This Type B Investigative Report provides an evaluation of all relevant events and activities that led to, were an integral part of, and subsequently resulted from ORNL's November-December 1985 strontium-90 release incident. The impacts were evaluated in terms of radiological doses to ORNL and Rust employees associated with the incident, ORGDP employees who consumed potable water potentially impacted by the incident, and Kingston, Tennessee, residents who also consumed potable water potentially impacted by the incident; and in terms of reductions in ORNL's low-level liquid radioactive waste storage capabilities. The management systems evaluated include: (1) those intended to reduce the potential of occurrence of such events and (2) those intended to provide adequate response to such events should they occur. Inherent in the management system evaluations were reviews of applicable planning activities and intra- and inter-organization communications. The composition of the investigation board and its appointment letter are contained in Appendix 1. The investigation process included analyses of existing procedures; analyses of environmental data collected just prior to, during, and subsequent to the event; and interviews and discussions with ORNL, ORGDP, DOE, and Rust Engineering personnel. In addition, written comments on the draft report were received from Rust Engineering (Letter from R.C. Stuck to B.C. Scott, dated February 24, 1986, Subject: Investigation of ORNL's November-December 1985 Strontium-90 Release Incident) and they were considered in the preparation of the final document

  17. Study of Nash equilibrium by increasing game parameters in 3-player quantum game

    Directory of Open Access Journals (Sweden)

    H Goudarzi

    2013-03-01

    Full Text Available  Using the quantum game formalism in 3-player system, we calculate the Nash equilibrium in quantum Prisoners’ Dilemma by increasing parameters of unitary operator. Since, the entanglement plays an important role in quantum states of particles quantum game, actually its effect on the obtained results of Nash equilibrium is investigated. It is shown that increasing the parameters enhances the game payoff function.

  18. Equilibrium expert: an add-in to Microsoft Excel for multiple binding equilibrium simulations and parameter estimations.

    Science.gov (United States)

    Raguin, Olivier; Gruaz-Guyon, Anne; Barbet, Jacques

    2002-11-01

    An add-in to Microsoft Excel was developed to simulate multiple binding equilibriums. A partition function, readily written even when the equilibrium is complex, describes the experimental system. It involves the concentrations of the different free molecular species and of the different complexes present in the experiment. As a result, the software is not restricted to a series of predefined experimental setups but can handle a large variety of problems involving up to nine independent molecular species. Binding parameters are estimated by nonlinear least-square fitting of experimental measurements as supplied by the user. The fitting process allows user-defined weighting of the experimental data. The flexibility of the software and the way it may be used to describe common experimental situations and to deal with usual problems such as tracer reactivity or nonspecific binding is demonstrated by a few examples. The software is available free of charge upon request.

  19. BetaScint{trademark} fiber-optic sensor for detecting strontium-90 and uranium-238 in soil. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-01

    Accurate measurements of radioactivity in soils contaminated with Strontium-90 (Sr-90) or Uranium-238 (U-238) are essential for many DOE site remediation programs. These crucial measurements determine if excavation and soil removal is necessary, where remediation efforts should be focused, and/or if a site has reached closure. Measuring soil contamination by standard EPA laboratory methods typically takes a week (accelerated analytical test turnaround) or a month (standard analytical test turnaround). The time delay extends to operations involving heavy excavation equipment and associated personnel which are the main costs of remediation. This report describes an application of the BetaScint{trademark} fiber-optic sensor that measures Sr-90 or U-238 contamination in soil samples on site in about 20 minutes, at a much lower cost than time-consuming laboratory methods, to greatly facilitate remediation. This report describes the technology, its performance, its uses, cost, regulatory and policy issues, and lessons learned.

  20. Investigation report of the release of strontium-90 from the Building 3517 cell ventilation improvements construction site on November 29, 1985, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1986-01-01

    This Type B Investigative Report provides an evaluation of all relevant events and activities that led to, were an integral part of, and subsequently resulted from ORNL's November-December 1985 strontium-90 release incident. The impacts were evaluated in terms of radiological doses to ORNL and Rust employees associated with the incident, ORGDP employees who consumed potable water potentially impacted by the incident, and Kingston, Tennessee, residents who also consumed potable water potentially impacted by the incident; and in terms of reductions in ORNL's low-level liquid radioactive waste storage capabilities. The management systems evaluated include: (1) those intended to reduce the potential of occurrence of such events and (2) those intended to provide adequate response to such events should they occur. Inherent in the management system evaluations were reviews of applicable planning activities and intra- and inter-organization communications. The composition of the investigation board and its appointment are contained in Appendix 1. 2 figs., 1 tab

  1. BetaScintTM fiber-optic sensor for detecting strontium-90 and uranium-238 in soil. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    Accurate measurements of radioactivity in soils contaminated with Strontium-90 (Sr-90) or Uranium-238 (U-238) are essential for many DOE site remediation programs. These crucial measurements determine if excavation and soil removal is necessary, where remediation efforts should be focused, and/or if a site has reached closure. Measuring soil contamination by standard EPA laboratory methods typically takes a week (accelerated analytical test turnaround) or a month (standard analytical test turnaround). The time delay extends to operations involving heavy excavation equipment and associated personnel which are the main costs of remediation. This report describes an application of the BetaScint trademark fiber-optic sensor that measures Sr-90 or U-238 contamination in soil samples on site in about 20 minutes, at a much lower cost than time-consuming laboratory methods, to greatly facilitate remediation. This report describes the technology, its performance, its uses, cost, regulatory and policy issues, and lessons learned

  2. Content of Strontium-90 in soils and sediments from the vicinity of the Kozloduy NPP for the period 2011-2012

    Energy Technology Data Exchange (ETDEWEB)

    Kamenova-Totzeva, R.; Kotova, R.; Tenev, J.; Ivanova, G.; Badulin, V. [Public Exposure Monitoring Laboratory, National Centre of Radiobiology and Radiation Protection, Sofia (Bulgaria)

    2013-07-01

    The National centre of radiobiology and radiation protection (NCRRP) – Sofia has carried out periodic radiation environmental monitoring and control of the region since the pre-operational period of the Nuclear power plant Kozloduy. The latest analytical results of the radiation monitoring for the period 2011- 2012 are described in this article. The object of study is the content of Strontium-90 in soils and bottom sediment samples at 17 points located from 6 to 90 km from the Kozloduy NPP. Obtained results of the investigation and analyses for the period 2011-2012 are shown in tables and figures. Annual results are compared with data from previous years as well as with data from the pre-operational period. (author)

  3. Equilibrium partitioning of macromolecules in confining geometries: Improved universality with a new molecular size parameter

    DEFF Research Database (Denmark)

    Wang, Yanwei; Peters, Günther H.J.; Hansen, Flemming Yssing

    2008-01-01

    structures (CABS), allows the computation of equilibrium partition coefficients as a function of confinement size solely based on a single sampling of the configuration space of a macromolecule in bulk. Superior in computational speed to previous computational methods, CABS is capable of handling slits...... parameter for characterization of spatial confinement effects on macromolecules. Results for the equilibrium partition coefficient in the weak confinement regime depend only on the ratio ofR-s to the confinement size regardless of molecular details....

  4. Trace Metals in Groundwater and the Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid West DOE

    International Nuclear Information System (INIS)

    Smith, Robert W.

    2004-01-01

    Radionuclide and metal contaminants such as strontium-90 are present beneath U.S. Department of Energy (DOE) lands in both the groundwater (e.g., 100-N area at Hanford, WA) and vadose zone (e.g., Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory). In situ containment and stabilization of these contaminants is a cost-effective treatment strategy. However, implementing in situ containment and stabilization approaches requires definition of the mechanisms that control contaminant sequestration. We are investigating the in situ immobilization of radionuclides or contaminant metals (e.g., strontium-90) by their facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Our facilitated approach, shown schematically in Figure 1, relies upon the hydrolysis of introduced urea to cause the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity. Subsurface urea hydrolysis is catalyzed by the urease enzyme, which may be either introduced with the urea or produced in situ by ubiquitous subsurface urea hydrolyzing microorganisms. Because the precipitation process tends to be irreversible and many western aquifers are saturated with respect to calcite, the co-precipitated metals and radionuclides will be effectively removed from the aqueous phase over the long-term. Another advantage of the ureolysis approach is that the ammonium ions produced by the reaction can exchange with radionuclides sorbed to subsurface minerals, thereby enhancing the availability of the radionuclides for re-capture in a more stable solid phase (co-precipitation rather than adsorption)

  5. The Efficiency of Strontium-90 Desorption Using Iron (III) Solutions in the Decontamination Process of Radioactive Soils

    OpenAIRE

    Olga Vladimirovna Cheremisina; Vasiliy Sergeev; Varvara Alabusheva; Alexander Fedorov; Alexandra Iliyna

    2018-01-01

    The paper presents the investigation on the estimated efficiency of iron (III) chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3)·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant ...

  6. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1990-07-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of Neural Network known as the multi-layer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author) 15 refs., 7 figs

  7. Relation between the conditions of helium ion implantation and helium void equilibrium parameters

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Rybalko, V.F.; Ruzhitskij, V.V.; Tolstolutskaya, G.D.

    1981-01-01

    The conditions of helium thermodynamic equilibrium in a system of voids produced by helium ion bombardment of a metal sample are studied. As an initial equation for description of the equilibrium the Clapeyron equation was used. The equation is obtained relating basic parameters of helium voids (average diameter and density) to irradiation parameters (dose, ion energy (straggling)) and properties of the metal (surface tension coefficient, yield strength). Comparison of the calculations with experimental data on helium in nickel found in literature shows that the equation yields satisfactory resutls for the dose range 1.10 16 -1x10 17 cm -2 and temperatures T [ru

  8. Fast non-linear extraction of plasma equilibrium parameters using a neural network mapping

    International Nuclear Information System (INIS)

    Lister, J.B.; Schnurrenberger, H.

    1991-01-01

    The shaping of non-circular plasmas requires a non-linear mapping between the measured diagnostic signals and selected equilibrium parameters. The particular configuration of neural network known as the multilayer perceptron provides a powerful and general technique for formulating an arbitrary continuous non-linear multi-dimensional mapping. This technique has been successfully applied to the extraction of equilibrium parameters from measurements of single-null diverted plasmas in the DIII-D tokamak; the results are compared with a purely linear mapping. The method is promising, and hardware implementation is straightforward. (author). 17 refs, 8 figs, 2 tab

  9. Acceptability of inversely-modelled parameters for non-equilibrium sorption of pesticides in soil

    NARCIS (Netherlands)

    Horst, ter M.M.S.; Boesten, J.J.T.I.; Beinum, van W.; Beulke, S.

    2013-01-01

    Simulation of the increase of sorption in time is one of the options in higher tiers of pesticide regulatory leaching assessments to obtain more realistic leaching estimates. Therefore, accurate estimates of non-equilibrium sorption parameters are required as input for the pesticide leaching

  10. Numerical study for determining PF coil system parameters in MHD equilibrium of KT-2 tokamak plasma

    International Nuclear Information System (INIS)

    Ryu, J.; Hong, S.H.; Lee, K.W.; Hong, B.G.; In, S.R.; Kim, S.K.

    1995-01-01

    The KT-2 is a large-aspect-ratio medium-sized divertor tokamak in the conceptual design phase and planned to be operational in 1998 at the Korea Atomic Energy Research Institute (KAERI). Plasma equilibrium in tokamak can be acquired by controlling the current of poloidal field (PF) coils in appropriate geometries and positions. In this study, the authors have performed numerical calculations to achieve the various equilibrium conditions fitting given plasma shapes and satisfying PF current limitations. Usually an ideal magnetohydrodynamic (MHD) equation is used to obtain the equilibrium solution of tokamak plasma, and it is practical to take advantage of a numerical method in solving the MHD equation because it has nonlinear source terms. Two equilibrium codes have been applied to find a double-null configuration of free-boundary tokamak plasma in KT-2: one is of the authors' own developing and the other is a free-boundary tokamak equilibrium code (FBT) that has been used mainly for the verification of developed code's results. PF coil system parameters including their positions and currents are determined for the optimization of input power required when the specifications of KT-2 tokamak are met. Then, several sets of equilibrium conditions during the tokamak operation are found to observe the changes of poloidal field currents with the passing of operation time step, and the basic stability problems related with the magnetic field structure is also considered

  11. Bifurcation and Stability Analysis of the Equilibrium States in Thermodynamic Systems in a Small Vicinity of the Equilibrium Values of Parameters

    Science.gov (United States)

    Barsuk, Alexandr A.; Paladi, Florentin

    2018-04-01

    The dynamic behavior of thermodynamic system, described by one order parameter and one control parameter, in a small neighborhood of ordinary and bifurcation equilibrium values of the system parameters is studied. Using the general methods of investigating the branching (bifurcations) of solutions for nonlinear equations, we performed an exhaustive analysis of the order parameter dependences on the control parameter in a small vicinity of the equilibrium values of parameters, including the stability analysis of the equilibrium states, and the asymptotic behavior of the order parameter dependences on the control parameter (bifurcation diagrams). The peculiarities of the transition to an unstable state of the system are discussed, and the estimates of the transition time to the unstable state in the neighborhood of ordinary and bifurcation equilibrium values of parameters are given. The influence of an external field on the dynamic behavior of thermodynamic system is analyzed, and the peculiarities of the system dynamic behavior are discussed near the ordinary and bifurcation equilibrium values of parameters in the presence of external field. The dynamic process of magnetization of a ferromagnet is discussed by using the general methods of bifurcation and stability analysis presented in the paper.

  12. The Efficiency of Strontium-90 Desorption Using Iron (III Solutions in the Decontamination Process of Radioactive Soils

    Directory of Open Access Journals (Sweden)

    Olga Vladimirovna Cheremisina

    2018-03-01

    Full Text Available The paper presents the investigation on the estimated efficiency of iron (III chloride solutions in the decontamination process of radioactive soils with 90 Sr, according to kinetic and thermodynamic characteristics of the desorption process. The specific 90 Sr radioactivity of soil samples was (3.9±0.3·104 Bq·g. The adsorption isotherms of Sr 2+ and Fe 3+ are described with the Langmuir equation. The values of Gibbs energy G0298 = -4.65 kJ·mol -1 and equilibrium ion exchange constant Keq = 6,5 confirm the hypothesis of strontium removal from soils with iron (III cations. The effectiveness of the method is substantiated by experimental and calculated results of this study samples of radioactive soils are deactivated in 90% after 9.5 hours, whereas the kinetic constant is 6.77·10 s -1 . The suggested method of soil cleanup with 0.2 M Fe 3+ solutions is optimal and complies with the environmental requirements.

  13. Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 1. Usage of bauxite wastes (red muds)

    Energy Technology Data Exchange (ETDEWEB)

    Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E.; Keskin, G. [Istanbul Univ. (Turkey). Faculty of Engineering

    1995-10-01

    Bauxite wastes of alumina manufacture, i.e., red muds, have been tested for radiocesium and strontium removal from water. The red muds were water-washed, acid-, and heat-treated before usage to produce hydrous oxide like sorbents. Surface treatment of the sorbent was beneficial for {sup 137}Cs uptake, while heat-treatment was detrimental to the -SOH surface sites responsible for high {sup 90}Sr affinity. Fractionation of the sorbent with respect to apparent grain size did not produce significant differences in the sorption efficiency. The distribution coefficients vs. equilibrium activity in solution showed a maximum with Cs, and a gradual decrease trend with Sr. The solution activity vs. adsorption data were fitted to B.E.T. (essentially types IV-V) isotherms for Cs and B.E.T.-Langmuir isotherms for Sr. Desorption, temperature-, pH-, and ionic strength-dependence tests revealed that the primary mode of sorption for both cations is specific adsorption while the secondary mode is ion exchange. A rise in pH favours the ion-exchange sorption of Sr while the specific adsorption of Cs is negatively affected. Competitive adsorption of an inert electrolyte, i.e., NaCl, severely hinders Cs sorption, while Sr sorption on water-washed red mud is not significantly affected. (author).

  14. Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 1. Usage of bauxite wastes (red muds)

    International Nuclear Information System (INIS)

    Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E.; Keskin, G.

    1995-01-01

    Bauxite wastes of alumina manufacture, i.e., red muds, have been tested for radiocesium and strontium removal from water. The red muds were water-washed, acid-, and heat-treated before usage to produce hydrous oxide like sorbents. Surface treatment of the sorbent was beneficial for 137 Cs uptake, while heat-treatment was detrimental to the -SOH surface sites responsible for high 90 Sr affinity. Fractionation of the sorbent with respect to apparent grain size did not produce significant differences in the sorption efficiency. The distribution coefficients vs. equilibrium activity in solution showed a maximum with Cs, and a gradual decrease trend with Sr. The solution activity vs. adsorption data were fitted to B.E.T. (essentially types IV-V) isotherms for Cs and B.E.T.-Langmuir isotherms for Sr. Desorption, temperature-, pH-, and ionic strength-dependence tests revealed that the primary mode of sorption for both cations is specific adsorption while the secondary mode is ion exchange. A rise in pH favours the ion-exchange sorption of Sr while the specific adsorption of Cs is negatively affected. Competitive adsorption of an inert electrolyte, i.e., NaCl, severely hinders Cs sorption, while Sr sorption on water-washed red mud is not significantly affected. (author)

  15. Effect of synthesis parameters on polymethacrylic acid xerogel structures and equilibrium swelling

    Science.gov (United States)

    Panić, V.; Jovanović, J.; Adnadjević, B.; Velicković, S.

    2009-09-01

    Hydrogels based on crosslinked polymethacrylic acid were synthesized via free-radical polymerization in aqueous solution, using N,N'-methylene bisacrylamide as a crosslinking agent and 2,2'-azobis-[2-(2-imidazolin-2-yl)propane] dihydrochloride as an initiator. The influence of the reaction parameters (the neutralization degree of methacrylic acid and the initial monomer concentration) on the equilibrium swelling degree, the swelling kinetic parameters and the basic structural properties of xerogels was investigated. The change of synthesis parameters leads to the change of the basic structural parameters of xerogel, as well as the equilibrium swelling degree and the initial swelling rate of the hydrogels. It is found that there are power form relationships between the equilibrium swelling degree, the initial swelling rate and the structural xerogel’s properties and the change of the neutralization degree of monomer, i.e. the monomer concentration. The examined correlations proved that the crosslinking density is the crucial parameter which determines all the other investigated structural and swelling parameters.

  16. The restricted stochastic user equilibrium with threshold model: Large-scale application and parameter testing

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Kjær; Nielsen, Otto Anker; Watling, David P.

    2017-01-01

    Equilibrium model (DUE), by combining the strengths of the Boundedly Rational User Equilibrium model and the Restricted Stochastic User Equilibrium model (RSUE). Thereby, the RSUET model reaches an equilibrated solution in which the flow is distributed according to Random Utility Theory among a consistently...... model improves the behavioural realism, especially for high congestion cases. Also, fast and well-behaved convergence to equilibrated solutions among non-universal choice sets is observed across different congestion levels, choice model scale parameters, and algorithm step sizes. Clearly, the results...... highlight that the RSUET outperforms the MNP SUE in terms of convergence, calculation time and behavioural realism. The choice set composition is validated by using 16,618 observed route choices collected by GPS devices in the same network and observing their reproduction within the equilibrated choice sets...

  17. Major parameters affecting the calculation of equilibrium factor using SSNTD-measured track densities

    International Nuclear Information System (INIS)

    Abo-Elmagd, M.; Mansy, M.; Eissa, H.M.; El-Fiki, M.A.

    2006-01-01

    The equilibrium factor F between radon and its daughters as a function of the track density ratio D/D 0 between bare and in can track detectors is solved graphically and gave more accurate solution than that solved mathematically elsewhere. The advantages of the graphical solution come from its simplicity and does not need any tedious mathematical formula or a computer program. The simplicity of this solution makes us study many parameters that affect the equilibrium factor determination such as the detector type, the diffusion chamber dimensions, the membrane specifications and the behavior of α-emitters around the detector. The results show that the equilibrium factor as a function of D/D 0 takes different form according to the facility used. The range of this study covers two widely used detectors (CR-39 and LR-115) equipped in two widely used diffusion chambers (small and medium chambers)

  18. Solid-Liquid equilibrium of n-alkanes using the Chain Delta Lattice Parameter model

    DEFF Research Database (Denmark)

    Coutinho, João A.P.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    1996-01-01

    The formation of a solid phase in liquid mixtures with large paraffinic molecules is a phenomenon of interest in the petroleum, pharmaceutical, and biotechnological industries among onters. Efforts to model the solid-liquid equilibrium in these systems have been mainly empirical and with different...... degrees of success.An attempt to describe the equilibrium between the high temperature form of a paraffinic solid solution, commonly known as rotator phase, and the liquid phase is performed. The Chain Delta Lattice Parameter model (CDLP) is developed allowing a successful description of the solid-liquid...... equilibrium of n-alkanes ranging from n-C_20 to n-C_40.The model is further modified to achieve a more correct temperature dependence because it severely underestimates the excess enthalpy. It is shown that the ratio of excess enthalpy and entropy for n-alkane solid solutions, as happens for other solid...

  19. Prediction of the working parameters of a wood waste gasifier through an equilibrium model

    Energy Technology Data Exchange (ETDEWEB)

    Altafini, Carlos R.; Baretto, Ronaldo M. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Wander, Paulo R. [Caxias do Sul Univ., Dept. of Mechanical Engineering, Caxias do Sul, RS (Brazil); Federal Univ. of Rio Grande do Sul State (UFRGS), Mechanical Engineering Postgraduation Program (PROMEC), RS (Brazil)

    2003-10-01

    This paper deals with the computational simulation of a wood waste (sawdust) gasifier using an equilibrium model based on minimization of the Gibbs free energy. The gasifier has been tested with Pinus Elliotis sawdust, an exotic specie largely cultivated in the South of Brazil. The biomass used in the tests presented a moisture of nearly 10% (wt% on wet basis), and the average composition results of the gas produced (without tar) are compared with the equilibrium models used. Sensitivity studies to verify the influence of the moisture sawdust content on the fuel gas composition and on its heating value were made. More complex models to reproduce with better accuracy the gasifier studied were elaborated. Although the equilibrium models do not represent the reactions that occur at relatively high temperatures ( {approx_equal} 800 deg C) very well, these models can be useful to show some tendencies on the working parameter variations of a gasifier. (Author)

  20. Pre-equilibrium assumptions and statistical model parameters effects on reaction cross-section calculations

    International Nuclear Information System (INIS)

    Avrigeanu, M.; Avrigeanu, V.

    1992-02-01

    A systematic study on effects of statistical model parameters and semi-classical pre-equilibrium emission models has been carried out for the (n,p) reactions on the 56 Fe and 60 Co target nuclei. The results obtained by using various assumptions within a given pre-equilibrium emission model differ among them more than the ones of different models used under similar conditions. The necessity of using realistic level density formulas is emphasized especially in connection with pre-equilibrium emission models (i.e. with the exciton state density expression), while a basic support could be found only by replacement of the Williams exciton state density formula with a realistic one. (author). 46 refs, 12 figs, 3 tabs

  1. The transfer of strontium-90 and caesium-137 to milk in a dairy herd grazing near a major nuclear installation

    Energy Technology Data Exchange (ETDEWEB)

    Sumerling, T J; Dodd, N J; Green, N

    1984-03-01

    A field investigation of the transfer of artificially produced radionuclides in the pasture--cow--milk pathway has been made at a farm close to the nuclear fuel reprocessing installation at Sellafield on the north-west coast of England. This paper reports results from analyses of samples collected during 1981, reports transfers coefficients for /sup 90/Sr and /sup 137/Cs from various types of feed to milk, and discusses factors that affect the transfer of these radionuclides. It is shown that during 1981 a large proportion of the /sup 90/Sr and /sup 137/Cs consumed by cattle grazing near Sellafield was derived from activity deposited in previous years. Transfer coefficients to milk, Fm, have been derived which are within the ranges of those observed in tracer and fallout studies. There are significant seasonal changes in transfer. For /sup 90/Sr, values of Fm between 9 X 10(-4)d 1(-1) and 4 X 10(-3)d 1(-1) have been obtained. It is concluded that this large range arises because daily intakes of /sup 90/Sr by the herd during the winter months are lower (by a factor of about 3) than intakes during the summer months and that the concentration of /sup 90/Sr in milk is not in equilibrium with intake, that is, the concentration of /sup 90/Sr in milk is maintained both by recent intakes and by remobilisation of activity that has been accumulated in bone from earlier intakes. For /sup 137/Cs, values of Fm between 3 X 10(-3)d 1(-1) and 9 X 10(-3)d 1(-1) have been obtained. It is concluded that this range most probably occurs because during the summer months, when the cows are grazing, a substantial proportion of the /sup 137/Cs intake is associated with soil on the surface of herbage and that, in this form, the /sup 137/Cs is less available for uptake from the digestive tract of the cows.

  2. The performance of simulated annealing in parameter estimation for vapor-liquid equilibrium modeling

    Directory of Open Access Journals (Sweden)

    A. Bonilla-Petriciolet

    2007-03-01

    Full Text Available In this paper we report the application and evaluation of the simulated annealing (SA optimization method in parameter estimation for vapor-liquid equilibrium (VLE modeling. We tested this optimization method using the classical least squares and error-in-variable approaches. The reliability and efficiency of the data-fitting procedure are also considered using different values for algorithm parameters of the SA method. Our results indicate that this method, when properly implemented, is a robust procedure for nonlinear parameter estimation in thermodynamic models. However, in difficult problems it still can converge to local optimums of the objective function.

  3. Prognostication of the radioactive contamination with iodine 131, strontium 90 and cesium 137 of the air and soil after commissioning the ''Kozloduj'' nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Khristova, M; Paskalev, Z [Nauchno-Izsledovatelski Inst. po Radiologiya i Radiatsionna Khigiena, Sofia (Bulgaria)

    1975-01-01

    The content of iodine 131, strontium 90 and cesium 137 in the air (curie/l) and soil (curie/m/sup 2/ sec) in the area of the Kozloduj atomic power station (at a distance from 3 to 75 km from the chimney-stack of the power station) was determined. The concentrations of these radionuclides are determined under different meteorologic conditions: air temperature from -20/sup 0/C to +20/sup 0/C and a wind speed from 2 m/sec to 30 m/sec. The data show that at -20/sup 0/C radionuclide concentrations in the air decrease with increasing distance from the chimney-stack, regardless of the speed of the wind. At +20/sup 0/C radionuclide concentrations in the air increase with the distance from the chimney-stack, peak at a definite distance and then decrease. At 2 m/sec and speed this maximum is at a distance of 50 km from station. As the speed of the air increases, the peak moves nearer and remains about 30 km from the power station. Results on ground surface concentrations show that a trend is observed toward persistent decrease with distance from the power station. In rainy weather they are almost four times higher than in dry weather. The radionuclide concentrations on the ground surface will be comparable to their global deposits.

  4. Caesium-137 and strontium-90 in the food chains: model development using fallout data. [Pasture-cow-milk pathway

    Energy Technology Data Exchange (ETDEWEB)

    Haywood, S M [National Radiological Protection Board, Harwell (UK)

    1980-11-01

    The development of the models for the movement of /sup 137/Cs and /sup 90/Sr in the pasture-cow-milk pathway is briefly discussed. Using recorded deposition rates of these radionuclides as input to the basic model, it was found that the models for /sup 137/Cs and /sup 90/Sr in their initial form were found to predict higher levels of activity in milk than those recorded. The predicted contributions of the processes of root uptake into pasture grass and the resuspension of deposited activity on to pasture surfaces were shown to be responsible for much of the overestimation. Following a re-evaluation of all transfer parameters, major improvements in the quality of fit between the model predictions and measured levels of /sup 137/Cs and /sup 90/Sr in milk were obtained.

  5. Rapid determination of strontium-90 in environmental samples by single Cerenkov counting using two different colour quench curves

    Energy Technology Data Exchange (ETDEWEB)

    Torres, J.M.; Garcia, J.F.; Llaurado, M.; Rauret, G. [Barcelona Univ. (Spain). Dept. de Quimica Analitica

    1996-11-01

    The validation of the Cerenkov radiation measurement of {sup 90}Y to determine the activity concentration of {sup 90}Sr in environmental samples is described. Liquid-liquid extraction with di-2-ethyhexylphosphoric acid in toluene was used to separate {sup 90}Y from {sup 90}Sr. Optimum conditions for Cerenkov counting (low-level counting option, counting windows, mass of solution to be measured) were established. The need for a counting efficiency correction by using a colour quench curve is stated to be essential, otherwise a significant error may occur. Two different colour quench curves (counting efficiency versus the channel ratio or spectral index parameter) were used and the results were compared. The method was applied to 12 environmental matrices: sea-water, algae, carobs, milk, almonds, hake, honey, shellfish, lamb meat, sardine, pork meat and shore sand. No significant differences were observed on using either of the two colour quench curves for any of these environmental matrices. In order to validate the proposed method, a certified soil reference material (CRM IAEA-375) was used, together with participation in an interlaboratory exercise to determine {sup 90}Sr in a natural water sample. Again, efficiency correction was performed by using either of the two colour quench curves and in both instances the calculated {sup 90}Sr activity concentration was in good agreement with the known values. (Author).

  6. How far are transmission measurements of pre-equilibrium stopping influenced by impact parameter selection?

    International Nuclear Information System (INIS)

    Semrad, D.; Bergsmann, M.; Bauer, P.; Diez-Muino, R.; Arnau, S.A.

    2000-01-01

    A slow ion that impinges on a target will need to travel a certain distance within the target - called pre-equilibrium length - in order to reach charge equilibrium. In this transient region, projectiles may suffer energy loss different from the mean value. For gas targets, most of the relevant cross-sections and energy transfers can be determined separately by experiment. This allows one to relate these data to the stopping cross-section and to simulate the passage of ions through gas by Monte-Carlo techniques. For solid targets matter is worse, but a universal formalism how pre-equilibrium processes may be determined from transmission data is well documented by Sigmund [14-15]. In transmission experiments usually only these projectiles are analyzed that have missed the central region of the target atoms. It is, however, a matter of fact that projectiles passing closer to the nucleus are more likely to lose energy. In the case of thin targets these projectiles are deflected out of the detector acceptance leading to a reduction of the measured average energy loss. Hence, stopping data may be influenced by so-called impact parameter selection (IPS) according to the layout of the experiment. This IPS clearly acts also in the regime of pre-equilibrium stopping. Using Monte-Carlo simulation we studied to which extent in a typical transmission experiment energy loss is influenced by pre-equilibrium stopping and by IPS, respectively. For feasibility, instead of a solid target, we follow the trajectories through a dense gas target. We find that in an actual experiment with small detector opening angle the formalism to describe pre-equilibrium stopping has to include IPS

  7. Final Technical Report for DOE Award DE-FG02-07ER64403 [Modeling of Microbially Induced Calcite Precipitation for the Immobilization of Strontium-90 Using a Variable Velocity Streamtube Ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Ginn, Timothy R. [University of California, Davis; Weathers, Tess [University of California, Davis

    2013-08-26

    Biogeochemical modeling using PHREEQC2 and a streamtube ensemble approach is utilized to understand a well-to-well subsurface treatment system at the Vadose Zone Research Park (VZRP) near Idaho Falls, Idaho. Treatment involves in situ microbially-mediated ureolysis to induce calcite precipitation for the immobilization of strontium-90. PHREEQC2 is utilized to model the kinetically-controlled ureolysis and consequent calcite precipitation. Reaction kinetics, equilibrium phases, and cation exchange are used within PHREEQC2 to track pH and levels of calcium, ammonium, urea, and calcite precipitation over time, within a series of one-dimensional advective-dispersive transport paths creating a streamtube ensemble representation of the well-to-well transport. An understanding of the impact of physical heterogeneities within this radial flowfield is critical for remediation design; we address this via the streamtube approach: instead of depicting spatial extents of solutes in the subsurface we focus on their arrival distribution at the control well(s). Traditionally, each streamtube maintains uniform velocity; however in radial flow in homogeneous media, the velocity within any given streamtube is spatially-variable in a common way, being highest at the input and output wells and approaching a minimum at the midpoint between the wells. This idealized velocity variability is of significance in the case of ureolytically driven calcite precipitation. Streamtube velocity patterns for any particular configuration of injection and withdrawal wells are available as explicit calculations from potential theory, and also from particle tracking programs. To approximate the actual spatial distribution of velocity along streamtubes, we assume idealized radial non-uniform velocity associated with homogeneous media. This is implemented in PHREEQC2 via a non-uniform spatial discretization within each streamtube that honors both the streamtube’s travel time and the idealized

  8. EQUILIBRIUM AND KINETIC PARAMETERS FOR THE SEDIMENTATION OF TARTARIC SALTS IN YOUNG WINES

    Directory of Open Access Journals (Sweden)

    Ecaterina Covaci

    2015-06-01

    Full Text Available In young wines potassium hydrogen tartrate is always present in supersaturating concentration and crystallizes spontaneously. The aim of this study is to obtain kinetic parameters, which explain the stability of young wines during the stabilization treatments. The kinetic and equilibrium parameters were evaluated and discussed. The heating factor has a decisive influence on the reaction rate of potassium hydrogen tartrate precipitation in young wines. An increase of temperature leads to a decrease in efficiency of stabilization process and to an enhancement of the activation energy of the system. According to the obtained experimental results, the optimal regime for production and stabilization of young wines has been established.

  9. Feasibility of a single-parameter description of equilibrium viscous liquid dynamics

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Christensen, Tage Emil; Schrøder, Thomas

    2008-01-01

    Molecular dynamics results for the dynamic Prigogine-Defay ratio are presented for two glass-forming liquids, thus evaluating the experimentally relevant quantity for testing whether metastable-equilibrium liquid dynamics is described by a single parameter to a good approximation. For the Kob......-Andersen binary Lennard-Jones mixture as well as for an asymmetric dumbbell model liquid, a single-parameter description works quite well. This is confirmed by time-domain results where it is found that energy and pressure fluctuations are strongly correlated on the alpha time scale in the constant...

  10. Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters: Research updated.

    Science.gov (United States)

    Chang, Yingju; Lai, Juin-Yih; Lee, Duu-Jong

    2016-12-01

    The standard Gibbs free energy, enthalpy and entropy change data for adsorption equilibrium reported in biosorption literature during January 2013-May2016 were listed. Since the studied biosorption systems are all near-equilibrium processes, the enthalpy and entropy change data evaluated by fitting temperature-dependent free energy data using van Hoff's equation reveal a compensation artifact. Additional confusion is introduced with arbitrarily chosen adsorbate concentration unit in bulk solution that added free energy change of mixing into the reported free energy and enthalpy change data. Different standard states may be chosen for properly describing biosorption processes; however, this makes the general comparison between data from different systems inappropriate. No conclusion should be drawn based on unjustified thermodynamic parameters reported in biosorption studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters.

    Science.gov (United States)

    Liu, Xiang; Lee, Duu-Jong

    2014-05-01

    This meta-analysis evaluates adsorption studies that report thermodynamic parameters for heavy metals and dyes from wastewaters. The adsorbents were derived from agricultural waste, industrial wastes, inorganic particulates, or some natural products. The adsorption mechanisms, derivation of thermodynamic relationships, and possible flaws made in such evaluation are discussed. This analysis shows that conclusions from the examined standard enthalpy and entropy changes are highly contestable. The reason for this flaw may be the poor physical structure of adsorbents tested, such that pore transport controlled the solute flux, leaving a surface reaction process near equilibrium. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Radiation from Radioactive Cesium (137 Cs) and Strontium (90Sr) Contaminated soil during the Chernobyl Nuclear Disaster Triggers Rice Immune Response

    International Nuclear Information System (INIS)

    Kimura, S.; Rakwal, R.; Agrawal, G. K.; Tamogami, S.; Kim, Y.H.; Shibato, J.; Sahoo, S. K.; Shiraishi, K.; Los, I. P.; Shevachuk, V. E.; Yonekura, M.; Iwahashi, H.

    2004-01-01

    After the Chernobyl nuclear accident in 1986 that exposed most of the population of the Northern hemisphere to various degrees of radiation, the public's perception of nuclear risk was completely changed. other than the obvious and much studied health impact, the agriculture and environmental impacts still pose a serious problem. Cesium-137, which has a half-life of 30.1 years, is the most important radionuclide left from Chernobyl's catastrophic explosion, and is present at high concentrations (activity, gamma-and beta-emitter) in the 0-5 cm soil layer. Strontium-90 (beta.emitter), which has a half-life of 29.1 years also constitutes a problem for plants. The effect of these radionuclides, and importantly show the radiation released therein affects plants has not been investigated in detail. In this study, we tested the hypothesis that leaves of two-week-old rice (japonica-type c, Nipponbare) seedlings (that constitutes a well-established in-vitro assay system) would respond to radiation (from the contaminated soil from Masany. Belarus, with major radionuclides, 137 Cs and 90 sr) by inducing various biochemical/molecular changes associated with the defense/stress response, including those involving mechanisms affecting the inactivation of damaging reactive oxygen specie. Rice (oryza sativa L.) is an enormously important food and monocot cereal crop research model whose draft genome sequence has recently been released. A molecular (northern analysis which provides a picture of the transcriptional changes of a particular gene), proteomics (two-dimensional electrophoresis (2-DE) is a powerful tool in understanding which proteins are present in particular tissue under given condition), and metabolomic (determining the metabolic profiles of metabolites induced during stress) approach was employed to monitor the changes in defense(stress-related (D/S-.r) genes, proteins (using 2-DE coupled with amino acid sequencing and immunoblotting) and metabolites (in particular

  13. 100-N Area Strontium-90 Treatability Demonstration Project: Food Chain Transfer Studies for Phytoremediation Along the 100-N Columbia River Riparian Zone

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, Robert J.; Fruchter, Jonathan S.; Driver, Crystal J.

    2009-04-01

    Strontium-90 (90Sr) exceeds the U.S. Environmental Protection Agency’s drinking water standards for groundwater (8 picocuries/L) by as much as a factor of 1000 at several locations within the Hanford 100-N Area and along the 100-N Area Columbia River shoreline). Phytoextraction, a managed remediation technology in which plants or integrated plant/rhizosphere systems are employed to phytoextract and/or sequester 90Sr, is being considered as a potential remediation system along the riparian zone of the Columbia River as part of a treatment train that includes an apatite barrier to immobilize groundwater transport of 90Sr. Phytoextraction would employ coyote willow (Salix exigua) to extract 90Sr from the vadose zone soil and aquifer sediments (phytoextraction) and filter 90Sr (rhizofiltration) from the shallow groundwater along the riparian zone of the Columbia River. The stem and foliage of coyote willows accumulating 90Sr may present not only a mechanism to remove the contaminant but also can be viewed as a source of nutrition for natural herbivores, therefore becoming a potential pathway for the isotope to enter the riparian food chain. Engineered barriers such as large and small animal fencing constructed around the field plot will control the intrusion of deer, rodents, birds, and humans. These efforts, however, will have limited effect on mobile phytophagous insects. Therefore, this study was undertaken to determine the potential for food chain transfer by insects prior to placement of the remediation technology at 100-N. Insect types include direct consumers of the sap or liquid content of the plants vascular system (xylem and phloem) by aphids as well as those that would directly consume the plant foliage such as the larvae (caterpillars) of Lepidoptera species. Heavy infestations of aphids feeding on the stems and leaves of willows growing in 90Sr-contaminated soil can accumulate a small amount (~0.15 ± 0.06%) of the total label removed from the soil by

  14. 100-N Area Strontium-90 Treatability Demonstration Project: Phytoextraction Along the 100-N Columbia River Riparian Zone – Field Treatability Study

    Energy Technology Data Exchange (ETDEWEB)

    Fellows, Robert J.; Fruchter, Jonathan S.; Driver, Crystal J.; Ainsworth, Calvin C.

    2010-01-11

    Strontium-90 (90Sr) is present both in the aquifer near the river and in the vadose and riparian zones of the river’s shore at 100-NR-2. Phytoextraction of 90Sr is being considered as a potential remediation system along the riparian zone of the Columbia River. Phytoextraction would employ coyote willow (Salix exigua). Past studies have shown that willow roots share uptake mechanisms for Sr with Ca, a plant macronutrient as well as no discrimination between Sr and 90Sr. Willow 90Sr concentration ratios [CR’s; (pCi 90Sr/g dry wt. of new growth tissue)/(pCi 90Sr/g soil porewater)] were consistently greater than 65 with three-quarters of the assimilated label partitioned into the above ground shoot. Insect herbivore experiments also demonstrated no significant potential for bioaccumulation or food chain transfer from their natural activities. The objectives of this field study were three-fold: (1) to demonstrate that a viable, “managed” plot of coyote willows can be established on the shoreline of the Columbia River that would survive the same microenvironment to be encountered at the 100-NR-2 shoreline; (2) to show through engineered barriers that large and small animal herbivores can be prevented from feeding on these plants; and (3) to show that once established, the plants will provide sufficient biomass annually to support the phytoextraction technology. A field treatability demonstration plot was established on the Columbia River shoreline alongside the 100-K West water intake at the end of January 2007. The plot was delimited by a 3.05 m high chain-link fence and was approximately 10 x 25 m in size. A layer of fine mesh metal small animal screening was placed around the plot at the base of the fencing to a depth of 45 cm. A total of sixty plants were placed in six slightly staggered rows with 1-m spacing between plants. The actual plot size was 0.00461 hectare (ha). At the time of planting (March 12, 2007), the plot was located about 10 m from the

  15. Structuring and capturing of radioactive strontium-90 from the polluted soil of Semipalatinsk nuclear test site by inter-polymer complexes

    International Nuclear Information System (INIS)

    Bimendina, L.A.; Kudaibergenov, S.E.; Orazzhanova, L.K.; Yashkarova, M.G.; Kaliaskarova, B.

    2002-01-01

    was investigated. The quantitative analysis of od strontium-90 by polymer solution in treated and untreated soil is carried out. It is shown, that the Sr 90 content increases twice in soils treated by separate polymer solutions (PAA or PEG) probably due to formation of PAA-Sr 2+ and PEG-Sr 2+ complexes. The most Sr 90 content was observed in soils treated by [PAA]:[PEG]=1:1 complex. Strontium content increases up to 9,34 μg/l in comparison with control experiments (2,31 μg/l) that may be connected with the formation of ternary PAA-Sr 2+ -PEG polymer-metal complexes

  16. Ingestion of radiocesium and strontium-90 by self-suppliers and non-self-suppliers in the first year following the Chernobyl reactor accident. Data taken as a basis for derivation of secondary intervention reference levels

    International Nuclear Information System (INIS)

    1988-01-01

    In Southeast Bavaria, the region of Germany with the highest Cs deposition, 20 self and non-self-suppliers were selected for observation of the ingestion and incorporation of radiocesium by means of check measurements of radioactivity in prepared diet duplicates and in the whole body. The results are comparatively analyzed. Surveys conducted in February/March 1987 show that both populations differ significantly in Cs incorporation. Children and adults among the self-suppliers revealed a Cs incorporation 3.5 times higher than that of the non-self-suppliers. An average Cs concentration of 8900 Bq was measured among the adult self-suppliers. By comparison, the average Cs concentration among the adult non-self-suppliers was only 2310 Bq. In the same period, a supply rate of 110 Bq/d (45-216 Bq/d) was measured among the adult self-suppliers, and a supply rate of 17 Bq/d (10-27 Bq/d) among the adult non-self-suppliers. The amount of activity incorporated per day was 77 Bq/d (64-96 Bq/d) among the younger children of the self-suppliers, and 32 Bq/d (24-40 Bq/d) among the older children of the non-self-suppliers. The specific activity of strontium 90 in dairy, meat and vegetable products mainly from the self-sufficiency areas was also analyzed. The average concentration of the activity of strontium 90 in raw milk was 0.4 Bq/l in February/March 1987, and the average specific activity for the other food products was 0.25-3 Bq/kg. The average values for the ingestion of strontium 90 over all the food products lie approximately between 0.3-0.5 Bq per person and day, and are comparable with the value of 0.3 Bq in the period before the reactor accident in Chernobyl. Starting from these values, the relative contamination of food as well as the effective dose equivalent of both groups of suppliers for the first year after the reactor accident in Chernobyl was measured. (orig./MG) [de

  17. An Equilibrium Chance-Constrained Multiobjective Programming Model with Birandom Parameters and Its Application to Inventory Problem

    Directory of Open Access Journals (Sweden)

    Zhimiao Tao

    2013-01-01

    Full Text Available An equilibrium chance-constrained multiobjective programming model with birandom parameters is proposed. A type of linear model is converted into its crisp equivalent model. Then a birandom simulation technique is developed to tackle the general birandom objective functions and birandom constraints. By embedding the birandom simulation technique, a modified genetic algorithm is designed to solve the equilibrium chance-constrained multiobjective programming model. We apply the proposed model and algorithm to a real-world inventory problem and show the effectiveness of the model and the solution method.

  18. The global equilibrium method and its hybrid implementation for identifying heterogeneous elastic material parameters

    KAUST Repository

    Lubineau, Gilles

    2011-04-01

    New identification strategies have to be developed in order to perform the identification quickly and at very-low cost. A popular class of approaches relies on full-field measurement obtained through digital image correlation. We propose here a global equilibrium approach. It is based on the virtual field method in case specific virtual fields are used. It can also be seen as a generalization of the equilibrium gap method. This approach is easy to implement and we prove that it provides better or comparable results to the constitutive equation gap method that is known to be a very accurate reference. © 2010 Elsevier B.V.

  19. Tables of homogeneous equilibrium critical flow parameters for water in SI units

    International Nuclear Information System (INIS)

    Hall, D.G.; Czapary, L.S.

    1980-09-01

    This reference document presents tables and charts containing data calculated using the homogeneous equilibrium critical flow model (HEM). The ranges of stagnation state properties for which data are presented include: pressures from 2 to 22 120kPa, temperatures from 290 to 640 K, and thermodynamic qualities from 0 to 1

  20. Effect of temperature on equilibrium and thermodynamic parameters of Cd (II) adsorption onto turmeric powder

    International Nuclear Information System (INIS)

    Qayoom, A.

    2012-01-01

    Summary: Batch adsorption of Cd (II) onto turmeric powder was conducted as a function of temperature. Nonlinear Langmuir, Freundlich, Dubinin-Radushkevish (D-R) and Temkin equilibrium models were employed. In addition to R 2, five different error functions were used to determine best fit equilibrium isotherm model. It was found that Freundlich isotherm model provided better fit for adsorption data at 298 and 303 K and Langmuir model was suitable for the experimental data obtained at 310 and 313 K. It was found that increase in temperature decreased maximum adsorption capacities, showing that the adsorption of Cd (II) onto turmeric powder is exothermic. Enthalpy values also confirmed the same trend. Entropy values were negative which means that randomness decreased on increasing temperature. Gibbs free energies were non spontaneous at all the temperatures studied. E values were in the range of 2.73-3.23 kJ mol/sup -1/ which indicated that adsorption mechanism is essentially physical. (author)

  1. Thermodynamic parameters for mixtures of quartz under shock wave loading in views of the equilibrium model

    International Nuclear Information System (INIS)

    Maevskii, K. K.; Kinelovskii, S. A.

    2015-01-01

    The numerical results of modeling of shock wave loading of mixtures with the SiO 2 component are presented. The TEC (thermodynamic equilibrium component) model is employed to describe the behavior of solid and porous multicomponent mixtures and alloys under shock wave loading. State equations of a Mie–Grüneisen type are used to describe the behavior of condensed phases, taking into account the temperature dependence of the Grüneisen coefficient, gas in pores is one of the components of the environment. The model is based on the assumption that all components of the mixture under shock-wave loading are in thermodynamic equilibrium. The calculation results are compared with the experimental data derived by various authors. The behavior of the mixture containing components with a phase transition under high dynamic loads is described

  2. Elements of a thermic method of preparing beta-sources with fused carriers, including strontium-90; Elements d'une methode thermique de preparation de sources beta avec des entraineurs fondus, y compris le strontium-90; Osnovy termicheskogo metoda prigotovleniya beta-istochnikov s plavlennymi nositelyami, vklyuchayushchimi strontsij-90; Bases de un metodo termico de preparacion de fuentes beta con portadores fundidos, incluido el estroncio-90

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanov, N I; Zakharova, K P; Zimakov, P V; Kulichenko, V V

    1962-01-15

    Sources of ionizing radiation based on the radioisotope Sr{sup 90} are widely used in apparatus and systems of automatic control and regulation of industrial processes. The technology of the preparation of sources is based on dehydration of a mixture of a radioactive solution of strontium nitrate with components such as boric anhydride, silica, and alumina. Thermic treatment of the dehydrated mixture at a high temperature produces a very mobile melt. This cools to a vitreous mass containing the required quantity of the radioisotope Sr{sup 90}. The paper gives data and discusses the results of dehydration of the system SrO - B{sub 2}O{sub 3} - SiO{sub 2} within a temperature range of 100 - 1000{sup o}C and justifies the choice of the main parameters of the technological process. It summarizes a method of mounting a vitreous preparation containing the required quantity of the radioisotope Sr{sup 90} on bases of various shapes and sizes made of steel, ceramic and other materials. The authors discuss the main parameters, ensuring that various types of sources shall be reliable and safe in operation, and give data of Sr{sup 90} sources prepared by the thermic method. (author) [French] Les sources de rayonnements ionisants a base de strontium-90 trouvent une large application dans les appareils et les systemes de controle et de reglage automatique des procedes de production. Le procede de preparation des sources se fonde sur la deshydratation d'un melange compose d'une solution radioactive de nitrate de strontium et d'elements comme l'anhydride borique, la silice, l'alumine, etc. Le traitement thermique du melange deshydrate a haute temperature donne lieu a la formation d'une masse fondue tres mobile, dont le refroidissement fournit une masse vitreuse contenant la quantite requise du radioisotope {sup 59}Sr. Les auteurs citent les donnees et examinent Jes resultats d'une etude sur la deshydratation du systeme SrO - B{sub 2}O{sub 3} - SiO{sub 2} a des temperatures

  3. Strontium-90 and plutonium-239/240 accumulation and distribution in soil-vegetative cover of some Semipalatinsk test site areas

    International Nuclear Information System (INIS)

    Tuleubaev, B.A.; Artem'ev, O.I.; Luk'yanova, Yu.A.; Sidorovich, T.V.; Silkina, G.P.; Kurmanbaeva, D.S.

    2001-01-01

    This paper presents results of field and laboratory studies of soil-vegetative cover contamination by 90 Sr and 239/240 Pu. Certain parameters of radionuclide migration in the environment of some former Semipalatinsk Test Site areas were determined. (author)

  4. Considerations about the correct evaluation of sorption thermodynamic parameters from equilibrium isotherms

    International Nuclear Information System (INIS)

    Salvestrini, Stefano; Leone, Vincenzo; Iovino, Pasquale; Canzano, Silvana; Capasso, Sante

    2014-01-01

    Highlights: • Different methods to derive sorption thermodynamic parameters have been discussed. • ΔG° and, ΔS° values depend on the selected standard states. • Isosteric heat values help in evaluating the applicability of the sorption models. -- Abstract: This is a comparative analysis of popular methods currently in use to derive sorption thermodynamic parameters from temperature dependence of sorption isotherms. It is emphasized that the standard and isosteric thermodynamic parameters have sharply different meanings. Moreover, it is shown with examples how the sorption model adopted conditions the standard state and consequently the value of ΔG° and ΔS°. These trivial but often neglected aspects should carefully be considered when comparing thermodynamic parameters from different literature sources. An effort by the scientific community is needed to define criteria for the choice of the standard state in sorption processes

  5. Approximate method of calculation of non-equilibrium flow parameters of chemically reacting nitrogen tetroxide in the variable cross-section channels with energy exchange

    International Nuclear Information System (INIS)

    Bazhin, M.A.; Fedosenko, G.Eh.; Shiryaeva, N.M.; Mal'ko, M.V.

    1986-01-01

    It is shown that adiabatic non-equilibrium chemically reacting gas flow with energy exchange in a variable cross-section channel may be subdivided into five possible types: 1) quasi-equilibrium flow; 2) flow in the linear region of deviation from equilibrium state; 3) quasi-frozen flow; 4) flow in the linear region of deviation from frozen state; 5) non-equilibrium flow. Criteria of quasi-equilibrium and quazi-frozen flows, including factors of external action of chemically reacting gas on flow, allow to obtain simple but sufficiently reliable approximate method of calculation of flow parameters. The considered method for solving the problem of chemically reacting nitrogen tetroxide in the variable cross-section channel with energy exchange can be used for evaluation of chemical reaction kinetics on the flow parameter in the stages of axial-flow and radial-flow turbines and in another practical problems

  6. Reliable Evaluation of Temperature-Independent Parameters in Correlation of Vapour–Liquid Equilibrium Data.

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Wichterle, Ivan

    2007-01-01

    Roč. 260, 1 (2007) , s. 70-73 ISSN 0378-3812 R&D Projects: GA ČR(CZ) GA104/03/1555 Institutional research plan: CEZ:AV0Z40720504 Keywords : temperature dependence of parameters * isometric pentanols * correlation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.506, year: 2007

  7. Prediction of equilibrium parameters of adsorption of lead (II) ions onto diatomite

    Science.gov (United States)

    Salman, Taylan; Ardalı, Yüksel; Gamze Turan, N.

    2013-04-01

    Heavy metals from industrial wastewaters are one of the most important environmental issues to be solved today. Due to their toxicity and nonbiodegradable nature, heavy metals cause environmental and public health problems. Various techniques have been developed to remove heavy metals from aqueous solutions. These include chemical precipitation, reverse osmosis, ion Exchange and adsorption. Among them, adsorption is considered to be a particularly competitive and effective process for the removal of heavy metals from aqueous solutions. There is growing interest in using low cost, commercially available materials for the adsorption of heavy metals. Diatomite is a siliceous sedimentary rock having an amorphous form of silica (SiO2. nH2O) containing a small amount of microcrystalline material. It has unique combination of physical and chemical properties such as high porosity, high permeability, small particle size, large surface area, and low thermal conductivity. In addition, it is available in Turkey and in various locations around the world. Therefore, diatomite has been successfully used as adsorbent for the removal of heavy metals. The aim of the study is to investigate the adsorption properties of diatomite. The equilibrium adsorption data were applied to the Langmuir, Freundlich and Dubinin-Radushkevic (D-R) isotherm models. Adsorption experiments were performed under batch process, using Pb (II) initial concentration, pH of solution and contact time as variables. The results demonstrated that the adsorption of Pb (II) was strongly dependent on pH of solution. The effect of pH on adsorption of Pb(II) on diatomite was conducted by varying pH from 2 to 12 at 20 oC. In the pH range of 2.0-4.0, the adsorption percentage increases slightly as the pH increasing. At pH>4, the adsorption percentage decreases with increasing pH because hydrolysis product and the precipitation begin to play an important role in the sorption of Pb (II). At pH4, the maximum adsorption

  8. First third filling parameters of left ventricle assessed from gated equilibrium studies in patients with various heart diseases

    Energy Technology Data Exchange (ETDEWEB)

    Adatepe, M.H.; Nichols, K.; Powell, O.M.; Isaacs, G.H.

    1984-01-01

    The authors determined the first third filling fraction (1/3 FF), the maximum filling rate (1/3 FR) and the mean filling rate (1/3 MFR) for the first third diastolic filling period of the left ventricle in patients with coronary artery disease (CAD), valvular heart disease (VHD), pericardial effusion (PE), cardiomyopathies (CM), chronic obstructive lung disease (COPD) and in 5 normals-all from resting gated equilibrium studies. Parameters are calculated from the third order Fourier fit to the LV volume curve and its derivative. 1/3 FF% = 1/3 diastolic count - end systolic count / 1/3 diastolic count x 100. Patients with CAD are divided into two groups: Group I with normal ejection fraction (EF) and wall motion (WM); Group II with abnormal EF and WM. Results are shown in the table. Abnormal filling parameters are found not only in CAD but in VHD, PE and CM. The authors conclude that the first third LV filling parameters are sensitive but non-specific indicators of filling abnormalities caused by diverse etiologic factors. Abnormal first third filling parameters may occur in the presence of a normal resting EF and WM in CAD.

  9. Strontium-90 in the US diet, 1982

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1984-07-01

    Estimates of 90 Sr intake via the total diet in New York City and San Francisco have been made since 1960 from quarterly food samplings and average consumption statistics. The dietary intake of 90 Sr has decreased from the maximum levels attained during 1963-1964, but the decline has become more gradual in recent years due to the continuing small amounts of 90 Sr deposition and the little-changing cumulative deposit of 90 Sr in soil. The annual intake in 1982 averaged 5.4 pCi/day (0.20 Bq/day) in New York, and 2.6 pCi/day (0.096 Bq/day) in San Francisco, little changed from the previous year. Further gradual reductions in 90 Sr intake are anticipated during 1983. 1 reference, 7 figures, 4 tables

  10. Determination of strontium-90 in soil samples

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C C

    1976-06-01

    The determination of /sup 90/Sr in soil by tri-n-butyl phosphate (TBP) is often interfered with iron which is always present in soil sample. Based on the method given by the U.S. Environmental Protection Agency, HClO/sub 4/ is added to remove iron ions while the soil sample is analyzed with TBP. The effect of different concentrations of HClO/sub 4/ on extraction yield of iron and chemical yield of yttrium is investigated. The experimental results show that 2N HClO/sub 4/ is the optimum concentration. The chemical yield of yttrium can reach about 60 percent, and all iron ions can be removed. This method has successfully been applied to analyze the soil samples taken from the site of the nuclear power plant in North Taiwan.

  11. Strontium-90 in the US diet, 1982

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1984-07-01

    Estimates of 90 Sr intake via the total diet in New York City and San Francisco have been made since 1960 from quarterly food samplings and average consumption statistics. The dietary intake of 90 Sr has decreased from the maximum levels attained during 1963 to 1964, but the decline has become more gradual in recent years due to the continuing small amounts of 90 Sr deposition and the little-changing cumulative deposit of 90 Sr in soil. The annual intake in 1982 averaged 5.4 pCi/day (0.20 Bq/day) in New York, and 2.6 pCi/day (0.096 Bq/day) in San Francisco, little changed from the previous year. Further gradual reductions in 90 Sr intake are anticipated during 1983. 11 references, 7 figures, 4 tables

  12. Strontium-90 and cesium-137 in soil

    International Nuclear Information System (INIS)

    1976-01-01

    To determine the total deposits of fallout, Japan Chemical Analysis Center has analyzed surface soil samples collected from 30 prefectures (30 locations) by the commission of Science and Technology Agency of Japanese Government. Soil samples were collected at depths of 0 -- 5 and 5 -- 20 cm on grassland or bare surface at each sampling location. Radiochemical analysis of these samples was carried out using the method recommended by Science and Technology Agency. One-hundred gram of soil was used as one sample for analysis. Results obtained during the period from July 1974 to March 1975 are shown in a table. (J.P.N.)

  13. (Surfactant + polymer) interaction parameter studied by (liquid + liquid) equilibrium data of quaternary aqueous solution containing surfactant, polymer, and salt

    Energy Technology Data Exchange (ETDEWEB)

    Foroutan, Masumeh [Physical Chemistry Department, School of Chemistry, College of Science, University of Tehran, 14155-6455 Tehran (Iran, Islamic Republic of)], E-mail: foroutan@khayam.ut.ac.ir; Heidari, Nosrat; Mohammadlou, Maryam [Chemistry Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of); Sojahrood, Amin Jafari [Physics Department, Faculty of Science, Uremia University, Uremia (Iran, Islamic Republic of)

    2009-02-15

    (Liquid + liquid) equilibrium (LLE) data of quaternary aqueous system containing polyoxyethylene (20) cetyl ether (with abbreviation name Brij 58, non-ionic surfactant), diammonium hydrogen phosphate, and poly ethylene glycol (PEG) with three molar masses {l_brace}M{sub W} = (1000, 6000, and 35,000) g . mol{sup -1}{r_brace} have been determined experimentally at T = 313.15 K. Furthermore, the Flory-Huggins theory with two electrostatic terms (Debye-Hueckel and Pitzer-Debye-Hueckel equations) have been used to calculate the phase behavior of the quaternary systems and (surfactant + polymer) interaction parameter as well as interaction parameters between other species. Temperature dependency of the parameters of the Flory-Huggins theory has been obtained. Also an effort have been done to show that addition of PEG as well as increasing the temperature can shift the binodal curves of the ternary aqueous system containing surfactant and salt to lower mole fraction of salt. Also the effect of polymer molar mass on the binodal diagram displacement has been discussed.

  14. Evaluation of specific tritium transfer parameters in equilibrium conditions for Cernavoda area

    International Nuclear Information System (INIS)

    Paunescu, N.; Galeriu, D.; Mocanu, N.; Margineanu, R.

    1998-01-01

    plants are low, as for an uncontaminated area. The presence of tritium in these samples is due to fallout. Steady-state conditions are achieved for environmental transfer of tritium in absence of local tritium source. Considering the environmental transfer model of Canadian standard, we calculated the transfer parameters for deposition from atmosphere on forage and crops, and the contamination of land and vegetation by spray irrigation water. (authors)

  15. Ultra-trace determination of Strontium-90 in environmental soil samples from Qatar by collision/reaction cell-inductively coupled plasma mass spectrometry (CRC-ICP-MS/MS)

    Energy Technology Data Exchange (ETDEWEB)

    Al-Meer, S. H.; Amr, M. A. [Central Laboratories Unit, Qatar University, Doha (Qatar); Helal, A.I. [Atomic Energy Authority, Cairo (Egypt); Al-Kinani, A.T. [Minstery of Environment, Doha (Qatar)

    2013-07-01

    Because of the very low level of {sup 90}Sr in the environmental soil samples and its determination by beta counting may take several weeks, we developed a procedure for ultra-trace determination of {sup 90}Sr using collision reaction cell-inductively coupled plasma tandem mass spectrometry (CRC-ICP-MS/MS, Agilent 8800). Soil samples were dried at 105 deg. C and then heated in a furnace at 550 deg. C to remove any organics present. 500 g of each soil samples were aliquoted into 2000 ml glass beakers. Each Soils samples were soaked in 2 ppm Sr solution carrier to allow determination of chemical yield. The solid to liquid ratio was 1:1. Finally the soil samples were dried at 105 deg. C. Five hundred milliliters concentrated nitric acid and 250 ml hydrochloric acid volumes were added on 500 g soil samples. The samples were digested on hot plate at 80 deg. C to prevent spraying with continuous manual mixing. The leachate solution was separated. The solids were rinsed with 500 ml deionized water, warmed on a hot plate and the leachate plus previous leachate were filtered and the total volume was reduced to 500 ml by evaporation. Final leachate volume was transferred to a centrifuge tubes. The centrifuge tubes were centrifuged at 3,500 rpm for 10 min. The leachate was transferred to a 1 L beaker and heated on a hot plate to evaporate the leachate to dryness. The reside was re-dissolved in 100 ml of 2% HNO{sub 3} and reduced by evaporation to 10 mL. The solution was measured directly by CRC-ICP-MS/MS by setting the first quadruple analyzer to m/z 90 and introducing oxygen gas into the reaction cell for elimination isobar interference from zirconium-90. The method was validated by measurements of standard reference materials and applied on environmental soil samples. The overall time requirement for the measurement of strontium-90 by CRC-ICP-MS/MS is 2 days, significantly shorter than any radioanalytical protocol currently available. (authors)

  16. Determination of strontium 90 in milk Ash; Dosage du strontium 90 dans les cendres de lait

    Energy Technology Data Exchange (ETDEWEB)

    Ballada, J; Jeanmaire, L [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    This report describes a method of determination of {sup 90}Sr in milk ashes by extraction of {sup 90}Y in TBP. The tests which led to the choice of the operating process are presented together with tire result of an intercomparison. (author) [French] Le document decrit une methode de dosage du {sup 90}Sr dans les cendres de lait par extraction de {sup 90}Y dans le TBP. De plus, les auteurs rapportent les essais qui ont conduit au choix du mode operatoire presente, ainsi que les resultats d'une intercomparaison. (auteur)

  17. Influence of Aloe arborescens Mill. extract on selected parameters of pro-oxidant-antioxidant equilibrium and cytokine synthesis in rowers.

    Science.gov (United States)

    Basta, Piotr; Pilaczyńska-Szczęśniak, Łucja; Woitas-Ślubowska, Donata; Skarpańska-Stejnborn, Anna

    2013-08-01

    This investigation examined the effect of supplementation with Biostimine, extract from Aloe arborescens Mill. leaves, on the levels of pro-oxidant-antioxidant equilibrium markers and anti- and proinflammatory cytokines in rowers subjected to exhaustive exercise. This double-blind study included 18 members of the Polish Rowing Team. Subjects were randomly assigned to the supplemented group (n = 9), which received one ampoule of Biostimine once daily for 4 weeks, or to the placebo group (n = 9). Subjects performed a 2,000-meter-maximum test on a rowing ergometer at the beginning and end of the preparatory camp. Blood samples were obtained from the antecubital vein before each exercise test, 1 min after completing the test and after a 24-hr recovery period. Superoxide dismutase and glutathione peroxidase activity as well as the concentration of thiobarbituric acid reactive substances (TBARS) were assessed in erythrocytes. In addition, total antioxidant capacity (TAC) and creatine kinase activity were measured in plasma samples, and cytokine (IL-6, IL-10) concentrations were determined in the serum. Before and after Biostimine supplementation, exercise significantly increased the values of SOD, IL-6, IL-10, and TBARS in both groups. However, postexercise and recovery levels of TBARS were significantly lower in athletes receiving Biostimine than in controls. After supplementation, TAC was the only variable with the level being significantly higher in the supplemented group than in the placebo group. Consequently, we can conclude that Biostimine supplementation reduces the postexercise level of TBARS by increasing the antioxidant activity of plasma but has no effect on inflammatory markers.

  18. Thermodynamic, Kinetic, and Equilibrium Parameters for the Removal of Lead and Cadmium from Aqueous Solutions with Calcium Alginate Beads

    Directory of Open Access Journals (Sweden)

    Ruth Alfaro-Cuevas-Villanueva

    2014-01-01

    Full Text Available The sorption of cadmium (Cd and lead (Pb by calcium alginate beads (CAB from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinetic data were fitted to Lagergren, pseudo-second-order and Elovich models and it was found that the second-order kinetic model describes these data for the two metals; comparing kinetic parameters for Cd and Pb sorption a higher kinetic rate (K2 for Pb was observed, indicating that the interaction between lead cations and alginate beads was faster than for cadmium. Similarly, isotherm data were fitted to different models reported in literature and it was found that the Langmuir-Freundlich (L-F and Dubinin-Radushkevich (D-R models describe the isotherms in all cases. CAB sorption capacity for cadmium was 27.4 mg/g and 150.4 mg/g for lead, at 25°C. Sorption capacities of Cd and Pb increase as temperature rises. According to the thermodynamic parameters, the cadmium and lead adsorption process was spontaneous and endothermic. It was also found that pH has an important effect on the adsorption of these metals by CAB, as more were removed at pH values between 6 and 7.

  19. Thermochemical parameters of minerals from oxygen-buffered hydrothermal equilibrium data: Method, application to annite and almandine

    Science.gov (United States)

    Zen, E.-A.

    1973-01-01

    Reversed univariant hydrothermal phase-equilibrium reactions, in which a redox reaction occurs and is controlled by oxygen buffers, can be used to extract thermochemical data on minerals. The dominant gaseous species present, even for relatively oxidizing buffers such as the QFM buffer, are H2O and H2; the main problem is to calculate the chemical potentials of these components in a binary mixture. The mixing of these two species in the gas phase was assumed by Eugster and Wones (1962) to be ideal; this assumption allows calculation of the chemical potentials of the two components in a binary gas mixture, using data in the literature. A simple-mixture model of nonideal mixing, such as that proposed by Shaw (1967), can also be combined with the equations of state for oxygen buffers to permit derivation of the chemical potentials of the two components. The two mixing models yield closely comparable results for the more oxidizing buffers such as the QFM buffer. For reducing buffers such as IQF, the nonideal-mixing correction can be significant and the Shaw model is better. The procedure of calculation of mineralogical thermochemical data, in reactions where hydrogen and H2O simultaneously appear, is applied to the experimental data on annite, given by Wones et al. (1971), and on almandine, given by Hsu (1968). For annite the results are: Standard entropy of formation from the elements, Sf0 (298, 1)=-283.35??2.2 gb/gf, S0 (298, 1) =+92.5 gb/gf. Gf0 (298, 1)=-1148.2??6 kcal, and Hf0 (298, 1)=-1232.7??7 kcal. For almandine, the calculation takes into account the mutual solution of FeAl2O4 (Hc) in magnetite and of Fe3O4 (Mt) in hercynite and the temperature dependence of this solid solution, as given by Turnock and Eugster (1962); the calculations assume a regular-solution model for this binary spinel system. The standard entropy of formation of almandine, Sf,A0 (298, 1) is -272.33??3 gb/gf. The third law entropy, S0 (298, 1) is +68.3??3 gb/gf, a value much less than the

  20. Higher adsorption capacity of Spirulina platensis alga for Cr(VI) ions removal: parameter optimisation, equilibrium, kinetic and thermodynamic predictions.

    Science.gov (United States)

    Gunasundari, Elumalai; Senthil Kumar, Ponnusamy

    2017-04-01

    This study discusses about the biosorption of Cr(VI) ion from aqueous solution using ultrasonic assisted Spirulina platensis (UASP). The prepared UASP biosorbent was characterised by Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer-Emmet-Teller, scanning electron spectroscopy and energy dispersive X-ray and thermogravimetric analyses. The optimum condition for the maximum removal of Cr(VI) ions for an initial concentration of 50 mg/l by UASP was measured as: adsorbent dose of 1 g/l, pH of 3.0, contact time of 30 min and temperature of 303 K. Adsorption isotherm, kinetics and thermodynamic parameters were calculated. Freundlich model provided the best results for the removal of Cr(VI) ions by UASP. The adsorption kinetics of Cr(VI) ions onto UASP showed that the pseudo-first-order model was well in line with the experimental data. In the thermodynamic study, the parameters like Gibb's free energy, enthalpy and entropy changes were evaluated. This result explains that the adsorption of Cr(VI) ions onto the UASP was exothermic and spontaneous in nature. Desorption of the biosorbent was done using different desorbing agents in which NaOH gave the best result. The prepared material showed higher affinity for the removal of Cr(VI) ions and this may be an alternative material to the existing commercial adsorbents.

  1. Deviations from thermal equilibrium in plasmas

    International Nuclear Information System (INIS)

    Burm, K.T.A.L.

    2004-01-01

    A plasma system in local thermal equilibrium can usually be described with only two parameters. To describe deviations from equilibrium two extra parameters are needed. However, it will be shown that deviations from temperature equilibrium and deviations from Saha equilibrium depend on one another. As a result, non-equilibrium plasmas can be described with three parameters. This reduction in parameter space will ease the plasma describing effort enormously

  2. Conceptual analyses of neutronic and equilibrium refueling parameters to develop a cost-effective multi-purpose pool-type research reactor using WIMSD and CITVAP codes

    Energy Technology Data Exchange (ETDEWEB)

    Hedayat, Afshin, E-mail: ahedayat@aeoi.org.ir

    2016-12-01

    Highlights: • Introducing a high-beneficent and low-cost multipurpose research reactor. • High technical documents and standard safety issues are introduced coherently. • High effective conceptual neutronic analyses and fuel management strategy. • Gaining high score design criteria and safety margins via 3-D core modeling. • Capacity and capability to produce all medical and industrial radioisotopes. - Abstract: In this paper, neutronic and equilibrium refueling parameters of a multi-purpose cost-effective research reactor have been studied and analyzed. It has been tried to provide periodic and long-term requirements of the irradiating applications coherently. The WIMSD5B and CITVAP codes are used to calculate neutronic parameters and simulate fuel management strategy. The used nuclear data, codes, and calculating methods have been severally benchmarked and verified, successfully. Fundamental concepts, design criteria, and safety issues are introduced and discussed, coherently. Design criteria are selected to gain the most economic benefits per capital costs via minimum required reactor power. Accurate, fast and simplified models have been tried for an integrated decision making and analyses using deterministic codes. Core management, power effects, fuel consumption and burn up effects, and also a complete simulation of the fuel management strategy are presented and analyzed. Results show that the supposed reactor core design can be promisingly suitable in accordance with the commercial multi-purpose irradiating applications. It also retains Operating Limits and Conditions (OLCs) due to standard safety issues, conservatively where safety parameters are calculated using best estimate tools. Such reactor core configuration and integrated refueling task can effectively enhance the Quality Assurance (QA) of the general irradiating applications of the current MTR within their power limits and corresponding OLCs.

  3. Errors in Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) Kinetic Temperature Caused by Non-Local Thermodynamic Equilibrium Model Parameters

    Science.gov (United States)

    Garcia-Comas, Maya; Lopez-Puertas, M.; Funke, B.; Bermejo-Pantaleon, D.; Marshall, Benjamin T.; Mertens, Christopher J.; Remsberg, Ellis E.; Mlynczak, Martin G.; Gordley, L. L.; Russell, James M.

    2008-01-01

    The vast set of near global and continuous atmospheric measurements made by the SABER instrument since 2002, including daytime and nighttime kinetic temperature (T(sub k)) from 20 to 105 km, is available to the scientific community. The temperature is retrieved from SABER measurements of the atmospheric 15 micron CO2 limb emission. This emission separates from local thermodynamic equilibrium (LTE) conditions in the rarefied mesosphere and thermosphere, making it necessary to consider the CO2 vibrational state non-LTE populations in the retrieval algorithm above 70 km. Those populations depend on kinetic parameters describing the rate at which energy exchange between atmospheric molecules take place, but some of these collisional rates are not well known. We consider current uncertainties in the rates of quenching of CO2 (v2 ) by N2 , O2 and O, and the CO2 (v2 ) vibrational-vibrational exchange to estimate their impact on SABER T(sub k) for different atmospheric conditions. The T(sub k) is more sensitive to the uncertainty in the latter two and their effects depend on altitude. The T(sub k) combined systematic error due to non-LTE kinetic parameters does not exceed +/- 1.5 K below 95 km and +/- 4-5 K at 100 km for most latitudes and seasons (except for polar summer) if the Tk profile does not have pronounced vertical structure. The error is +/- 3 K at 80 km, +/- 6 K at 84 km and +/- 18 K at 100 km under the less favourable polar summer conditions. For strong temperature inversion layers, the errors reach +/- 3 K at 82 km and +/- 8 K at 90 km. This particularly affects tide amplitude estimates, with errors of up to +/- 3 K.

  4. Contribution of Chernobyl accident to human contamination with strontium-90

    International Nuclear Information System (INIS)

    Botezatu, Elena; Iacob, Olga

    1998-01-01

    The Romanian surveys performed after the Chernobyl accident pointed out the environmental and diet contamination with 90 Sr at levels of one-two orders of magnitude higher than prior to the accident. Given the 90 Sr osteo-tropism we have been interested in its accumulation in the human teeth and bone. The search on 90 Sr accumulation in human teeth evidenced concentrations of 10.8 - 330 mBq/g Ca in milk teeth of young children born during 1986 - 1987 subsequent to Chernobyl. These values were 10-600 times higher than those obtained for permanent or deciduous teeth of all the other age groups or of the same age group born before Chernobyl. There was more 90 Sr activity concentration in ribs than in femur. The highest values of 90 Sr content (mBq/g Ca) were of 75-122 in ribs and 74-120 in femur for 7-10 years old group. These individuals were 0-3 years old during the period of greatest deposition. This age is by far the most critical years due to the heaviest uptake. Smaller concentration values were recorded for the age group older than 55, respectively of 3-20 in ribs and 3.3-10.2 in femur. Our data suggest that the Chernobyl accident did not lead to the increase of 90 Sr accumulation in adults. From the collective equivalent doses of 1500 manSv for bone surfaces and 680 manSv for active red marrow, a potential number of 4 radiation-induced fatal cancers in the studied population (5,2 mil.inh) has been estimated as attributable to Chernobyl accident

  5. Strontium-90 and cesium-137 in tea (Japanese tea)

    International Nuclear Information System (INIS)

    1983-01-01

    Sr-90 and Cs-137 in Japanese tea were determined using radiochemical analysis. Five hundred grams of manufactured green tea was collected from six sampling locations in June 1983, carbonized and ashed in a stainless steel pan or a porcelain dish. The maximum values of Sr-90 and Cs-137 were 250 +- 6.0 pCi/kg and 88.0 +- 3.2 pCi/kg, respectively, in tea collected from Tagata-gun, Shizuoka. (Namekawa, K.)

  6. Strontium-90 in the diet: results through 1980

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1981-01-01

    Estimates of 90 Sr intake via the total diet in New York City and San Francisco have been made since 1960 from quarterly food samplings and average consumption statistics. The dietary intakes of 90 Sr have decreased from the maximum levels attained during 1963 to 1964, but the declines have become more gradual in recent years due to the continuing small amounts of 90 Sr deposition and the little-changing cumulative deposit of 90 Sr in soil. The annual intake in 1980 averaged 6.0 pCi/day (0.22 Bq/day) in New York and 2.5 pCi/day (0.092 Bq/day) in San Francisco, slightly lower than the results of the previous year. Further gradual reductions in 90 Sr intake are anticipated during 1981

  7. Strontium-90 and cesium-137 in raw milk

    International Nuclear Information System (INIS)

    1979-01-01

    Under the commission of Science and Technology Agency, prefectural public health laboratories and institutes and Japan Chemical Analysis Center have measured the levels of 90 Sr and 137 Cs in milk samples. Sampling was done as follows: 4 times of raw milk samples a year in 10 prefectures for the report to WHO, 2 times of raw milk samples a year in 4 prefectures; and 2 times of city milk samples a year in 29 prefectures. Three litters of fresh milk were collected and carbonated in the prefectural public health laboratories and institutes of each prefecture, and the carbonated samples were collected at Japan Chemical Analysis Center. At Japan Chemical Analysis Center, these collected samples were radiochemically analysed for 90 Sr and 137 Cs using the method applied for the analysis of the radionuclides contents in total diet materials. (author)

  8. Strontium-90 and cesium-137 in total diet

    International Nuclear Information System (INIS)

    1979-01-01

    Under the commission of Science and Technology Agency, prefectural public health laboratories and institutes and Japan Chemical Analysis Center have collected total diet samples, and determined the contents of 90 Sr and 137 Cs in these samples. Thirty-two prefectural public health laboratories and institutes have collected 2 times a year all the daily regular diet consumed for five persons, namely three meals and other eating between them. These samples were collected at Japan Chemical Analysis Center after carbonization without smoke rising. At Japan Chemical Analysis Center, these samples were ashed in an electric muffle furnace. And the ash to which both some carriers were added were destroyed with hydrochloric acid and nitric acid. The nuclides were dissolved into hydrochloric acid and filtrated, after it was added with nitric acid. The nuclides were dissolved into hydrochloric acid and filtrated, after it was added with nitric acid. The samples solution including radionuclides was extracted with hydrochloric acid and water, and 90 Y which reached radioactive equivallence to 90 Sr, and 137 Cs were chemically separated from it. And the radioactivity was measured with low back ground beta-ray spectrometer. (author)

  9. Leaching behaviour of strontium-90 in cement composites

    International Nuclear Information System (INIS)

    Matsuzuru, H.; Ito, A.

    1977-01-01

    The leaching of 90 Sr from a cement composite into an aqueous phase has been studied by the method recommended by IAEA. The amount leached was measured as functions of waste to cement ratio (Wa/C), salt content of waste, temperature of leachant and curing time of specimens. The leach coefficient of 90 Sr varies from ca. 6 x 10 -8 to 4 x 10 -7 cm 2 /day depending on the composition of specimen and the leaching conditions. The leachability depends on such factors as Wa/C, temperature of leachant and curing time. The Portland cement composite gives a higher leaching fraction than the slag cement one. Additives used have no significant effect on the leachability. The amount leached in deionized water as a leachant is higher than in synthetic sea water. On the basis of the results obtained, the amount of 90 Sr leached from a composite of 200 1 drum size for an extended period was estimated. (author)

  10. Investigation of Cerenkov counting of environmental strontium-90

    International Nuclear Information System (INIS)

    Reynolds, S.A.; Eldridge, J.S.

    1979-01-01

    A typical liquid scintillation counter was evaluated for detection of low levels of 90 Sr-Y. A blank of about 5 cpm and 90 Y efficiency of 42% were obtained for 20-ml samples. The corresponding minimum detectable concentration for a 100-minute count is 0.03 pCi/ml, so that measurement of water samples can readily be made at the maximum permissible concentration for 90 Sr, 0.3 pCi/ml. The efficiency for 90 Sr is less than 0.4%, 1.4% for 137 Cs, and less than 0.04% for gamma-emitting 85 Sr, a useful tracer. Some data for 90 Y efficiencies and blanks are given for other liquid scintillation counters. Chemical treatments are necessary in some cases to concentrate 90 Sr-Y, to remove colored substances which cause quenching, or to eliminate interfering radionuclides. However, the manipulations need not be as elaborate as in conventional radiochemical analysis methods for 90 Sr. Ferric ion (yellow) quenches at the 5 ppM level, but the interference can be eliminated by adding a reducing agent. The Rn daughter 214 Bi, an interfering radionuclide, disappears by decay in 2-3 hours after removal of Rn by sweeping with air or gas. Concentration-separation methods studied have included precipitation and ion exchange

  11. Therapy of canine corneal pannus with strontium-90

    International Nuclear Information System (INIS)

    Hoecht, S.; Nausner, M.; Hinkelbein, W.; Gruening, G.; Allgoewer, I.; Brunnberg, L.

    2002-01-01

    Background: Corneal pannus is a disease which, if untreated, nearly always is progressive and may lead to blindness of the affected dog. A therapeutic standard is yet to be defined. Beta-ray irradiation with Sr-90 is often recommended on a casuistic basis, but systematic studies are sparse. The aim of the present study was to evaluate efficacy and to document side effects of radiotherapy with Sr-90. Material and Methods: 17 animals were treated. 13 of them received treatment of 15 Gy surface dose twice within 2 days with additional medical therapy with ciclosporin and prednisolon. Only the more affected eye was treated with radiation which was applied with an eye-applicator, the other eye served as control. Four animals with already advanced impairment of vision received keratectomy, afterwards radiation was applied on both sides. Results: Medical treatment alone led to deterioration in vascularization and spread of pigmentation in eleven of 13 (85%) of the control-eyes, density of pigmentation increased in eight of 13 (62%). After radiation therapy, almost all animals showed a marked initial improvement. Even if progressive disease occurred later on, further worsening as it happened in the control-eyes could be stopped in nine resp. ten of 13 eyes (69% and 77%). All animals with keratectomy and radiotherapy regained and preserved adequate vision. Besides short-term blepharospasm, no side effects were recorded. Conclusion: Corneal pannus is responsive to radiation therapy with Sr-90 and long-term benefit can be achieved. Side effects are minimal. Optimal sequencing of therapy and dosage still have to be examined. (orig.) [de

  12. Neutronic assessment of strontium-90 transmutation in fusion reactors

    International Nuclear Information System (INIS)

    Parish, T.A.

    1979-01-01

    Transmutation of 90 Sr using fusion neutrons has been suggested as a possible technique for disposing of this waste nuclide. For transmutation to be attractive, high transmutation rates relative to natural decay are required. Effective half-lives for 90 Sr were computed for fusion reactor blankets constructed of various materials. To obtain satisfactory transmutation rates, fusion reactors with high first wall neutron currents and with highly moderating blankets were found to be necessary. An effective half-life for 90 Sr of 90 Sr inventory and the number of burners required for various fission usage scenarios. Efficient and fast chemical separations were needed to reap the benefits of a short effective half-life. For the fusion burners considered, it was found that the 90 Sr inventory could not be reduced to less than one-fourth of the inventory without transmutation if fission usage continued at a constant rate. Such a reduction is not sufficient to justify the transmutation disposal of 90 Sr

  13. Strontium-90 and cesium-137 in milk (powdered milk)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in powdered milk were determined using radiochemical analysis. Six brands of commercial milk were purchased as samples in consuming districts in December 1984. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 33 +- 1.0 pCi/kg and 140 +- 2 pCi/kg, respectively, in skim milk manufactured by Meiji. (Namekawa, K.)

  14. Strontium-90 and cesium-137 in milk (powdered milk)

    International Nuclear Information System (INIS)

    1985-01-01

    Sr-90 and Cs-137 in powdered milk were determined using radiochemical analysis. Four brands of commercial milk were purchased as samples in consuming districts in June and July 1985. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 31 +- 1.2 pCi/kg and 62 +- 1.5 pCi/kg, respectively, in skim milk manufactured by Meiji. (Namekawa, K.)

  15. Fabrication of three 2500-watt (thermal) strontium-90 heat sources

    International Nuclear Information System (INIS)

    DeVore, J.R.; Haff, K.W.; Tompkins, J.A.

    1986-08-01

    Three 2500-watt (thermal) heat sources were fabricated by the Oak Ridge National Laboratory (ORNL) for the purpose of fueling a 500-watt (electric) thermoelectric generator as part of the US Department of Energy's Byproducts Utilization Program (BUP). Each of the sources, which are the largest ever assembled, consist of hot-pressed pellets of 90 Sr fluoride, doubly encapsulated in three Haynes-25 inner capsules and in a Hastelloy-S outer capsule. The total 90 Sr inventory of all three sources is 1.12 million curies. The sources were fabricated at the ORNL Fission Product Development Laboratory (FPDL), which is a facility that is capable of processing multi-megacurie quantities of radioactive materials, chiefly 137 Cs and 90 Sr. The source was tested to determine compliance with all of the IAEA Safety Series No. 33 requirements. The source fabrication, assembly, and testing are described in the presentation

  16. Strontium-90 in the western Gulf of Mexico

    International Nuclear Information System (INIS)

    Payton, P.H.; Hild, S.B.; Oertti, C.U.; Suttle, A.D. Jr.

    1977-01-01

    The results of measurements of 90 Sr in water, coral, hermit crabs and molluscs from the western Gulf of Mexico and in fresh water molluscs from Canyon Lake, Texas are reported. Preparation of samples for measurement in the anticoincidence mode in a lead shielded flow proportional counter is described. The measured value of 0.095 +- 0.003 pCi/litre for Gulf water is in accord with literature values. Concentration factors for 90 Sr are apparently 1 for coral. The activity incorporated into shells normalized to calcium content, decreases from Galveston to Campeche Bay. (U.K.)

  17. Technological developments for strontium-90 determination using AMS

    Energy Technology Data Exchange (ETDEWEB)

    Satou, Yukihiko, E-mail: yukihiko@ied.tsukuba.ac.jp [Accelerator Mass Spectrometry Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Sueki, Keisuke; Sasa, Kimikazu; Matsunaka, Tetsuya; Takahashi, Tsutomu; Shibayama, Nao; Izumi, Daiki [Accelerator Mass Spectrometry Group, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Kinoshita, Norikazu [Institute of Technology, Shimizu Corporation, 3-4-17 Etchujima, Koto-ku, Tokyo 135-8530 (Japan); Matsuzaki, Hiroyuki [The University Museum, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan)

    2015-10-15

    Accelerator mass spectrometry (AMS) is one of method used for {sup 90}Sr determination. It would enable rapid {sup 90}Sr measurements from environmental samples such as water, soil, and milk. However, routine analysis of {sup 90}Sr using AMS has not yet been achieved because of difficulties associated with isobaric separation and production of intense negative ion beams characterized by currents from hundreds of nanoamperes to several microamperes. We have developed a rapid procedure for preparing samples with optimum compositions for use with AMS, which enables production of intense Sr beam currents from an ion source. Samples of SrF{sub 2} were prepared from a standard Sr solution and agricultural soil. The time required to prepare a SrF{sub 2} sample from a soil sample was 10 h. Negative {sup 88}SrF{sub 3}{sup −} ions were successfully extracted at 500 nA from mixed samples of SrF{sub 2} and PbF{sub 2}. In the present work, negative ions of {sup 90}Zr, included as an impurity, were accelerated with a tandem accelerator operated at a terminal voltage of 5 MV. Ions characterized by a charge state of 6+ were channeled into a gas counter. An atomic ratio of {sup 90}Zr/{sup 88}Sr of 3 × 10{sup −8} was estimated for the soil sample. No signal was detected from the assay of PbF{sub 2}, which was pressed in an aluminum cathode, for a mass number of 90. PbF{sub 2} revealed good performance in the production of negative SrF{sub 3}{sup −} molecular ion beams and detection of {sup 90}Sr with a gas counter.

  18. Strontium-90 and cesium-137 in tea (Japanese tea)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in Japanese tea were determined using radiochemical analysis. Five hundred grams of manufactured green tea was collected from six sampling locations in June 1984, carbonized and ashed in a stainless steel pan or a porcelain dish. The maximum value of Sr-90 was 88+-3.7 pCi/kg in tea collected from Kyoto; the maximum value of Cs-137 was 99.0+-3.60 pCi/kg collected from Kagoshima. (Namekawa, K.)

  19. Nucleic acid components from strontium-90 exposed miniature swine

    International Nuclear Information System (INIS)

    Frazier, M.E.

    1976-01-01

    The reverse transcriptase associated with porcine type C virus particles was used to generate a tritium-labeled DNA product complementary to the viral RNA template. Results of nucleic acid hybridization experiments indicate this 3 H-DNA (probe) was copied from heteropolymeric regions of the procine viral RNA. Probe prepared from this porcine type C virus contains sequences that possess some homology in sequence to RNA isolated from viruses known to cause similar diseases in other animals

  20. Simplified method of analysis of Strontium-90 in milk

    International Nuclear Information System (INIS)

    Suomela, J.

    1987-06-01

    The milk sample is freeze-dried and the milk powder ignited. The ash is dissolved in hydrochloric acid and yttrium is extracted from the solution by 5% HDEHP (dioctyl phosforic acid). After re-extraction in nitric acid the Cherenkov radiation of yttrium 90 is measured in a low beta liquid scintillation counter. (O.S.)

  1. Rapid determination of strontium-89 and strontium-90

    International Nuclear Information System (INIS)

    Hellmuth, K.H.

    1987-05-01

    The main purpose of this study was to run experiments on rapid methods for radiostrontium determination. The aim was also to check the order of magnitude of radiostrontium directly available to plant uptake by roots. A brief inspection of the methods available showed that there is no ideal rapid method. Paying attention to interference from other nuclides, the 90 Sr content of a variety of substances, such as milk, grass and soil could be determined by a two step extraction method with tributyl phosphate. Despite the short waiting time needed for the necessary ingrowth of 90 Y, the first results were available soon after the accident. Comparison with the results obtained by the conventional nitrate separation method later showed the firs results to be fairly accurate. One of the important radionuclides, 89 Sr, could not be determined with the rapid methods used. It was evident from our results that the fallout from Chernobyl contained only a negligible amount of 90 Sr. The levels in soil, grass and milk indicated that the increase of 90 Sr as a result of the accident was within the limits of error of the measurements. The few air-filter samples analysed, however, could not be assessed because of interference from Ce isotopes. Another rapid separation method used for samples with a low Ca content, such as wet and dry deposition using the extraction of Sr as thenoyltrifluoracetylacetonate and subsequent liquid scintillation counting, was not successful under conditions of fresh fallout. Experiences after the reactor accident clearly show that there is a need to develop rapid methods for 89,90 Sr determination

  2. Strontium-90 in the bottom sediments of some Finnish lakes

    Energy Technology Data Exchange (ETDEWEB)

    Ilus, E.; Puhakainen, M.; Saxen, R

    1999-07-01

    The {sup 90}Sr concentrations in surface waters varied from 14 to 29 Bq m{sup -3} in 1988 and from 16 to 23 Bq m{sup -3} in 1990. In Lake Pielinen almost all the {sup 90}Sr seemed to originate from weapons test fallout, whereas in Lakes Ontojaervi, Naesijaervi and Pyhaejaervi the share of the Chernobyl fallout was equal to that of weapons test fallout. In the sediments, the total amount of {sup 90}Sr per square metre varied from 97 to 1060 Bq m{sup -2} in 1988 and from 310 to 1160 Bq m{sup -2} in 1990. The maximum values occurred in Lake Naesijaervi. The local amount of deposition and the type of sediment were the most important factors affecting strontium values in sediments. In addition, the large variation in total amounts of {sup 90}Sr was due to other environmental factors. The total amounts of {sup 90}Sr in sediments were generally of the same order of magnitude as the {sup 90}Sr deposition on the ground in the area. The concentrations of {sup 90}Sr in surface waters also conformed quite well to the distribution pattern of the deposition values. At some stations there was a clear maximum in a deeper sediment layer, which could be construed as a marker of the nuclear weapons tests in the 1960s. (orig.)

  3. Strontium-90 and cesium-137 in freshwater fish

    International Nuclear Information System (INIS)

    1983-01-01

    Sr-90 and Cs-137 in freshwater fish were determined using radiochemical analysis. Three species of fish (Carassius auratus, Cyprinus carpio, and Hypomesus transpacificus nipponensis) were collected during the fishing season from seven sampling locations. Only edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonized, the sample was ashed in an electric muffle furnace. The maximum values of Sr-90 and Cs-137 were 49.0 +- 1.30 pCi/kg and 8.5 +- 0.64 pCi/kg in Carassius auratus collected from Kyoto and Fukui, respectively, in December 1983. (Namekawa, K.)

  4. Therapy of canine corneal pannus with strontium-90; Die Behandlung der Keratitis superficialis chronica des Hundes mit Strontium-90

    Energy Technology Data Exchange (ETDEWEB)

    Hoecht, S.; Nausner, M.; Hinkelbein, W. [Universitaetsklinikum Benjamin Franklin, Berlin (Germany). Klinik und Poliklinik fuer Radioonkologie und Strahlentherapie; Gruening, G.; Allgoewer, I.; Brunnberg, L. [Freie Univ. Berlin (Germany). Klinik und Poliklinik fuer Kleine Haustiere

    2002-02-01

    Background: Corneal pannus is a disease which, if untreated, nearly always is progressive and may lead to blindness of the affected dog. A therapeutic standard is yet to be defined. Beta-ray irradiation with Sr-90 is often recommended on a casuistic basis, but systematic studies are sparse. The aim of the present study was to evaluate efficacy and to document side effects of radiotherapy with Sr-90. Material and Methods: 17 animals were treated. 13 of them received treatment of 15 Gy surface dose twice within 2 days with additional medical therapy with ciclosporin and prednisolon. Only the more affected eye was treated with radiation which was applied with an eye-applicator, the other eye served as control. Four animals with already advanced impairment of vision received keratectomy, afterwards radiation was applied on both sides. Results: Medical treatment alone led to deterioration in vascularization and spread of pigmentation in eleven of 13 (85%) of the control-eyes, density of pigmentation increased in eight of 13 (62%). After radiation therapy, almost all animals showed a marked initial improvement. Even if progressive disease occurred later on, further worsening as it happened in the control-eyes could be stopped in nine resp. ten of 13 eyes (69% and 77%). All animals with keratectomy and radiotherapy regained and preserved adequate vision. Besides short-term blepharospasm, no side effects were recorded. Conclusion: Corneal pannus is responsive to radiation therapy with Sr-90 and long-term benefit can be achieved. Side effects are minimal. Optimal sequencing of therapy and dosage still have to be examined. (orig.) [German] Hintergrund: Die Keratitis superficialis chronica des Hundes ist eine unbehandelt fast immer progredient verlaufende Hornhautentzuendung, die zur Erblindung fuehren kann. Eine Standardbehandlung gibt es bisher nicht. Systematische Untersuchungen zur Bestrahlung mit Strontium-(Sr-)90 liegen praktisch nicht vor, die Anwendung wird jedoch immer wieder propagiert. Ziel der Untersuchung war es, Wirksamkeit und Nebenwirkungen dieser Therapie zu dokumentieren. Material und Methoden: Behandelt wurden 17 Tiere. Bei 13 erfolgte neben einer medikamentoesen Behandlung mit Ciclosporin und Prednisolon eine Bestrahlung mit 2 x 15 Gy Oberflaechendosis mit einem Sr-90-Augenapplikator innerhalb von 2 Tagen. Behandelt wurde jeweils das schwerer erkrankte Auge, das andere Auge diente als Kontrolle. Bei vier weiteren Tieren mit initial bereits erheblicher Visuseinschraenkung erfolgte zusaetzlich eine Keratektomie, beide Augen wurden anschliessend bestrahlt. Ergebnisse: Bei fast allen Tieren (11/13; 85%) zeigte sich an den nur medikamentoes behandelten Augen eine Verschlechterung der Ausdehnung der Pigmentierung und der Vaskularisation, auch die Pigmentdichte war bei 8/13 (62%) zunehmend. Nach Radiotherapie kam es bei den meisten Tieren zu einer initialen deutlichen Besserung. Auch wenn es im weiteren Verlauf oft zu einem erneuten Schub der Erkrankung kam, konnte bei neun bzw. zehn von 13 Tieren (69% bzw. 77%) eine weitere Verschlechterung, wie sie am Kontrollauge auftrat, verhindert werden. Bei allen keratektomierten und bestrahlten Hunden konnte ein alltagstauglicher Visus wiedererlangt und erhalten werden. Ausser einem passageren Blepharospasmus traten keine Nebenwirkungen auf. Schlussfolgerung: Der Verlauf der Keratitis superficialis chronica laesst sich durch eine Bestrahlung mit Sr-90 ohne relevante Nebenwirkungen nachhaltig positiv beeinflussen. Die optimale Therapiesequenz und Dosierung muessen noch erarbeitet werden. (orig.)

  5. Local equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    From 3-6 September the First International Workshop on Local Equilibrium in Strong Interaction Physics took place in Bad-Honnef at the Physics Centre of the German Physical Society. A number of talks covered the experimental and theoretical investigation of the 'hotspots' effect, both in high energy particle physics and in intermediate energy nuclear physics.

  6. Equilibrium Dialysis

    African Journals Online (AJOL)

    context of antimicrobial therapy in malnutrition. Dialysis has in the past presented technical problems, being complicated and time-consuming. A new dialysis system based on the equilibrium technique has now become available, and it is the principles and practical application of this apparatus (Kontron Diapack; Kontron.

  7. Strategic Equilibrium

    NARCIS (Netherlands)

    van Damme, E.E.C.

    2000-01-01

    An outcome in a noncooperative game is said to be self-enforcing, or a strategic equilibrium, if, whenever it is recommended to the players, no player has an incentive to deviate from it.This paper gives an overview of the concepts that have been proposed as formalizations of this requirement and of

  8. Maximin equilibrium

    NARCIS (Netherlands)

    Ismail, M.S.

    2014-01-01

    We introduce a new concept which extends von Neumann and Morgenstern's maximin strategy solution by incorporating `individual rationality' of the players. Maximin equilibrium, extending Nash's value approach, is based on the evaluation of the strategic uncertainty of the whole game. We show that

  9. Trace Metals in Groundwater and Vadose Zone Calcite: In Situ Containment and Stabilization of Strontium-90 and Other Divalent Metals and Radionuclides at Arid Western DOE Sites: Final Report for Award Number DE-FG07-02ER63486 to the University of Idaho (RW Smith) Environmental Management Science Program Project Number 87016

    International Nuclear Information System (INIS)

    Smith, Robert W.; Fujita, Yoshiko

    2007-01-01

    Radionuclide and metal contaminants are present in the vadose zone and groundwater throughout the U.S. Department of Energy (DOE) energy research and weapons complex. In situ containment and stabilization of these contaminants represents a cost-effective treatment strategy that minimizes workers exposure to hazardous substances, does not require removal or transport of contaminants, and generally does not generate a secondary waste stream. We have investigated an in situ bioremediation approach that immobilizes radionuclides or contaminant metals (e.g., strontium-90) by their microbially facilitated co-precipitation with calcium carbonate in groundwater and vadose zone systems. Calcite, a common mineral in many aquifers and vadose zones in the arid west, can incorporate divalent metals such as strontium, cadmium, lead, and cobalt into its crystal structure by the formation of a solid solution. Collaborative research undertaken by the Idaho National Laboratory (INL), University of Idaho, and University of Toronto as part of this Environmental Management Science Program project has focused on in situ microbially-catalyzed urea hydrolysis, which results in an increase in pH, carbonate alkalinity, ammonium, calcite precipitation, and co-precipitation of divalent cations. In calcite-saturated aquifers, microbially facilitated co-precipitation with calcium carbonate represents a potential long-term contaminant sequestration mechanism. Key results of the project include: **Demonstrating the linkage between urea hydrolysis and calcite precipitation in field and laboratory experiments **Observing strontium incorporation into calcite precipitate by urea hydrolyzers with higher distribution coefficient than in abiotic **Developing and applying molecular methods for characterizing microbial urease activity in groundwater including a quantitative PCR method for enumerating ureolytic bacteria **Applying the suite of developed molecular methods to assess the feasibility of the

  10. Sweatshop equilibrium

    OpenAIRE

    Chau, Nancy H.

    2009-01-01

    This paper presents a capability-augmented model of on the job search, in which sweatshop conditions stifle the capability of the working poor to search for a job while on the job. The augmented setting unveils a sweatshop equilibrium in an otherwise archetypal Burdett-Mortensen economy, and reconciles a number of oft noted yet perplexing features of sweatshop economies. We demonstrate existence of multiple rational expectation equilibria, graduation pathways out of sweatshops in complete abs...

  11. Equilibrium constant and nitrogen activity and the parameters of interaction eN(N), rN(N,Cr), rN(N,Mn) in high nitrogen steels of Fe-Cr-Mn-N type

    International Nuclear Information System (INIS)

    Svyazhin, A.G.; Siwka, J.; Rashev, T.

    1999-01-01

    In the paper a description of a thermodynamic of liquid solutions of Fe-Cr-Mn-N type with using a concept of parameters of an interaction has been presented. A temperature relationship of the equilibrium constant K N(Fe) and values of self interaction parameters e N (N) , r N (N,Cr) , r N (N,Mn) and t N (N,Cr,Cr) has been determined for mean values of temperatures of liquid metal equal 1990 K and 2090 K. By application of a theory of regular solutions those values were recalculated for a temperature 1873 K. (orig.)

  12. Evolutions and equilibrium parameters of foam films from individual solutions of Bovine serum albumin, n-dodecyl-β-D-maltoside and from their mixed solutions

    Science.gov (United States)

    Gerasimova, Anelia Tsvetanova; Angarska, Jana Krumova; Tachev, Krasimir Dimov

    2017-03-01

    The evolutions of thinning of films from individual solutions of BSA, C12G2 and from their mixed solutions with molar ratios 1:1, 1:7.5, 1:50 and 1:100 with pH = 4.9 were recorded by modified (with video camera) interferometric method. Based on them the stages through which the film goes from its formation to the equilibrium state were distinguished. It was shown that: (i) the difference between the kinetic of drainage of films stabilized by high and low molecular surfactants is drastic; (ii) only the change of the pH solution under or above isoelectric point strongly retards the film drainage; (iii) the transition of the kinetic of thinning of films from mixed solutions from a kinetic typical for high molecular substances towards a kinetic for low substances depends on the molar ratio between the components in the solution. From the picture of film corresponding to its equilibrium state the type of film was determined. From the analysis of this picture the equilibrium thickness and contact angle were calculated. It was found that the criterion for Newtonium black films (based on the values of film thickness and contact angle) is not directly applicable for films from protein solutions or mixed solutions with the participation of proteins.

  13. Equilibrium Trust

    OpenAIRE

    Luca Anderlini; Daniele Terlizzese

    2009-01-01

    We build a simple model of trust as an equilibrium phenomenon, departing from standard "selfish" preferences in a minimal way. Agents who are on the receiving end of an other to transact can choose whether to cheat and take away the entire surplus, taking into account a "cost of cheating." The latter has an idiosyncratic component (an agent's type), and a socially determined one. The smaller the mass of agents who cheat, the larger the cost of cheating suffered by those who cheat. Depending o...

  14. Equilibrium thermodynamics

    CERN Document Server

    de Oliveira, Mário J

    2017-01-01

    This textbook provides an exposition of equilibrium thermodynamics and its applications to several areas of physics with particular attention to phase transitions and critical phenomena. The applications include several areas of condensed matter physics and include also a chapter on thermochemistry. Phase transitions and critical phenomena are treated according to the modern development of the field, based on the ideas of universality and on the Widom scaling theory. For each topic, a mean-field or Landau theory is presented to describe qualitatively the phase transitions. These theories include the van der Waals theory of the liquid-vapor transition, the Hildebrand-Heitler theory of regular mixtures, the Griffiths-Landau theory for multicritical points in multicomponent systems, the Bragg-Williams theory of order-disorder in alloys, the Weiss theory of ferromagnetism, the Néel theory of antiferromagnetism, the Devonshire theory for ferroelectrics and Landau-de Gennes theory of liquid crystals. This new edit...

  15. A Multiperiod Equilibrium Pricing Model

    Directory of Open Access Journals (Sweden)

    Minsuk Kwak

    2014-01-01

    Full Text Available We propose an equilibrium pricing model in a dynamic multiperiod stochastic framework with uncertain income. There are one tradable risky asset (stock/commodity, one nontradable underlying (temperature, and also a contingent claim (weather derivative written on the tradable risky asset and the nontradable underlying in the market. The price of the contingent claim is priced in equilibrium by optimal strategies of representative agent and market clearing condition. The risk preferences are of exponential type with a stochastic coefficient of risk aversion. Both subgame perfect strategy and naive strategy are considered and the corresponding equilibrium prices are derived. From the numerical result we examine how the equilibrium prices vary in response to changes in model parameters and highlight the importance of our equilibrium pricing principle.

  16. Non-equilibrium phase transitions

    CERN Document Server

    Henkel, Malte; Lübeck, Sven

    2009-01-01

    This book describes two main classes of non-equilibrium phase-transitions: (a) static and dynamics of transitions into an absorbing state, and (b) dynamical scaling in far-from-equilibrium relaxation behaviour and ageing. The first volume begins with an introductory chapter which recalls the main concepts of phase-transitions, set for the convenience of the reader in an equilibrium context. The extension to non-equilibrium systems is made by using directed percolation as the main paradigm of absorbing phase transitions and in view of the richness of the known results an entire chapter is devoted to it, including a discussion of recent experimental results. Scaling theories and a large set of both numerical and analytical methods for the study of non-equilibrium phase transitions are thoroughly discussed. The techniques used for directed percolation are then extended to other universality classes and many important results on model parameters are provided for easy reference.

  17. Gated equilibrium bloodpool scintigraphy

    International Nuclear Information System (INIS)

    Reinders Folmer, S.C.C.

    1981-01-01

    This thesis deals with the clinical applications of gated equilibrium bloodpool scintigraphy, performed with either a gamma camera or a portable detector system, the nuclear stethoscope. The main goal has been to define the value and limitations of noninvasive measurements of left ventricular ejection fraction as a parameter of cardiac performance in various disease states, both for diagnostic purposes as well as during follow-up after medical or surgical intervention. Secondly, it was attempted to extend the use of the equilibrium bloodpool techniques beyond the calculation of ejection fraction alone by considering the feasibility to determine ventricular volumes and by including the possibility of quantifying valvular regurgitation. In both cases, it has been tried to broaden the perspective of the observations by comparing them with results of other, invasive and non-invasive, procedures, in particular cardiac catheterization, M-mode echocardiography and myocardial perfusion scintigraphy. (Auth.)

  18. Equilibrium distributions

    International Nuclear Information System (INIS)

    Lysenko, W.P.

    1978-01-01

    A discussion is given of a calculation method for beam matching into a linac taking into account the space charge forces, which is a six-dimensional problem in phase space. Results for beam emittance, bunch radius, and space-charge parameter are shown

  19. Comparison of adsorption equilibrium and kinetic models for a case study of pharmaceutical active ingredient adsorption from fermentation broths: parameter determination, simulation, sensitivity analysis and optimization

    Directory of Open Access Journals (Sweden)

    B. Likozar

    2012-09-01

    Full Text Available Mathematical models for a batch process were developed to predict concentration distributions for an active ingredient (vancomycin adsorption on a representative hydrophobic-molecule adsorbent, using differently diluted crude fermentation broth with cells as the feedstock. The kinetic parameters were estimated using the maximization of the coefficient of determination by a heuristic algorithm. The parameters were estimated for each fermentation broth concentration using four concentration distributions at initial vancomycin concentrations of 4.96, 1.17, 2.78, and 5.54 g l−¹. In sequence, the models and their parameters were validated for fermentation broth concentrations of 0, 20, 50, and 100% (v/v by calculating the coefficient of determination for each concentration distribution at the corresponding initial concentration. The applicability of the validated models for process optimization was investigated by using the models as process simulators to optimize the two process efficiencies.

  20. Thermal equilibrium of goats.

    Science.gov (United States)

    Maia, Alex S C; Nascimento, Sheila T; Nascimento, Carolina C N; Gebremedhin, Kifle G

    2016-05-01

    The effects of air temperature and relative humidity on thermal equilibrium of goats in a tropical region was evaluated. Nine non-pregnant Anglo Nubian nanny goats were used in the study. An indirect calorimeter was designed and developed to measure oxygen consumption, carbon dioxide production, methane production and water vapour pressure of the air exhaled from goats. Physiological parameters: rectal temperature, skin temperature, hair-coat temperature, expired air temperature and respiratory rate and volume as well as environmental parameters: air temperature, relative humidity and mean radiant temperature were measured. The results show that respiratory and volume rates and latent heat loss did not change significantly for air temperature between 22 and 26°C. In this temperature range, metabolic heat was lost mainly by convection and long-wave radiation. For temperature greater than 30°C, the goats maintained thermal equilibrium mainly by evaporative heat loss. At the higher air temperature, the respiratory and ventilation rates as well as body temperatures were significantly elevated. It can be concluded that for Anglo Nubian goats, the upper limit of air temperature for comfort is around 26°C when the goats are protected from direct solar radiation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Experimental determination of some equilibrium parameter of Damavand tokamak by magnetic probe measurements for representing a physical model for plasma vertical movement.

    Science.gov (United States)

    Farahani, N Darestani; Davani, F Abbasi

    2015-10-01

    This investigation is about plasma modeling for the control of vertical instabilities in Damavand tokamak. This model is based on online magnetic measurement. The algebraic equation defining the vertical position in this model is based on instantaneous force-balance. Two parameters in this equation, including decay index, n, and lambda, Λ, have been considered as functions of time-varying poloidal field coil currents and plasma current. Then these functions have been used in a code generated for modeling the open loop response of plasma. The main restriction of the suitability analysis of the model is that the experiments always have to be performed in the presence of a control loop for stabilizing vertical position. As a result, open loop response of the system has been identified from closed loop experimental data by nonlinear neural network identification method. The results of comparison of physical model with identified open loop response from closed loop experiments show root mean square error percentage less than 10%. The results are satisfying that the physical model is useful as a Damavand tokamak vertical movement simulator.

  2. Thermodynamic theory of equilibrium fluctuations

    International Nuclear Information System (INIS)

    Mishin, Y.

    2015-01-01

    The postulational basis of classical thermodynamics has been expanded to incorporate equilibrium fluctuations. The main additional elements of the proposed thermodynamic theory are the concept of quasi-equilibrium states, a definition of non-equilibrium entropy, a fundamental equation of state in the entropy representation, and a fluctuation postulate describing the probability distribution of macroscopic parameters of an isolated system. Although these elements introduce a statistical component that does not exist in classical thermodynamics, the logical structure of the theory is different from that of statistical mechanics and represents an expanded version of thermodynamics. Based on this theory, we present a regular procedure for calculations of equilibrium fluctuations of extensive parameters, intensive parameters and densities in systems with any number of fluctuating parameters. The proposed fluctuation formalism is demonstrated by four applications: (1) derivation of the complete set of fluctuation relations for a simple fluid in three different ensembles; (2) fluctuations in finite-reservoir systems interpolating between the canonical and micro-canonical ensembles; (3) derivation of fluctuation relations for excess properties of grain boundaries in binary solid solutions, and (4) derivation of the grain boundary width distribution for pre-melted grain boundaries in alloys. The last two applications offer an efficient fluctuation-based approach to calculations of interface excess properties and extraction of the disjoining potential in pre-melted grain boundaries. Possible future extensions of the theory are outlined.

  3. Metronidazole removal in powder-activated carbon and concrete-containing graphene adsorption systems: Estimation of kinetic, equilibrium and thermodynamic parameters and optimization of adsorption by a central composite design.

    Science.gov (United States)

    Manjunath, S V; Kumar, S Mathava; Ngo, Huu Hao; Guo, Wenshan

    2017-12-06

    Metronidazole (MNZ) removal by two adsorbents, i.e., concrete-containing graphene (CG) and powder-activated carbon (PAC), was investigated via batch-mode experiments and the outcomes were used to analyze the kinetics, equilibrium and thermodynamics of MNZ adsorption. MNZ sorption on CG and PAC has followed the pseudo-second-order kinetic model, and the thermodynamic parameters revealed that MNZ adsorption was spontaneous on PAC and non-spontaneous on CG. Subsequently, two-parameter isotherm models, i.e., Langmuir, Freundlich, Temkin, Dubinin-Radushkevich and Elovich models, were applied to evaluate the MNZ adsorption capacity. The maximum MNZ adsorption capacities ([Formula: see text]) of PAC and CG were found to be between 25.5-32.8 mg/g and 0.41-0.002 mg/g, respectively. Subsequently, the effects of pH, temperature and adsorbent dosage on MNZ adsorption were evaluated by a central composite design (CCD) approach. The CCD experiments have pointed out the complete removal of MNZ at a much lower PAC dosage by increasing the system temperature (i.e., from 20°C to 40°C). On the other hand, a desorption experiment has shown 3.5% and 1.7% MNZ removal from the surface of PAC and CG, respectively, which was insignificant compared to the sorbed MNZ on the surface by adsorption. The overall findings indicate that PAC and CG with higher graphene content could be useful in MNZ removal from aqueous systems.

  4. A Strategic-Equilibrium Based

    Directory of Open Access Journals (Sweden)

    Gabriel J. Turbay

    2011-03-01

    Full Text Available The strategic equilibrium of an N-person cooperative game with transferable utility is a system composed of a cover collection of subsets of N and a set of extended imputations attainable through such equilibrium cover. The system describes a state of coalitional bargaining stability where every player has a bargaining alternative against any other player to support his corresponding equilibrium claim. Any coalition in the sable system may form and divide the characteristic value function of the coalition as prescribed by the equilibrium payoffs. If syndicates are allowed to form, a formed coalition may become a syndicate using the equilibrium payoffs as disagreement values in bargaining for a part of the complementary coalition incremental value to the grand coalition when formed. The emergent well known-constant sum derived game in partition function is described in terms of parameters that result from incumbent binding agreements. The strategic-equilibrium corresponding to the derived game gives an equal value claim to all players.  This surprising result is alternatively explained in terms of strategic-equilibrium based possible outcomes by a sequence of bargaining stages that when the binding agreements are in the right sequential order, von Neumann and Morgenstern (vN-M non-discriminatory solutions emerge. In these solutions a preferred branch by a sufficient number of players is identified: the weaker players syndicate against the stronger player. This condition is referred to as the stronger player paradox.  A strategic alternative available to the stronger players to overcome the anticipated not desirable results is to voluntarily lower his bargaining equilibrium claim. In doing the original strategic equilibrium is modified and vN-M discriminatory solutions may occur, but also a different stronger player may emerge that has eventually will have to lower his equilibrium claim. A sequence of such measures converges to the equal

  5. Equilibrium problems for Raney densities

    Science.gov (United States)

    Forrester, Peter J.; Liu, Dang-Zheng; Zinn-Justin, Paul

    2015-07-01

    The Raney numbers are a class of combinatorial numbers generalising the Fuss-Catalan numbers. They are indexed by a pair of positive real numbers (p, r) with p > 1 and 0 0 and similarly use both methods to identify the equilibrium problem for (p, r) = (θ/q + 1, 1/q), θ > 0 and q \\in Z+ . The Wiener-Hopf method is used to extend the latter to parameters (p, r) = (θ/q + 1, m + 1/q) for m a non-negative integer, and also to identify the equilibrium problem for a family of densities with moments given by certain binomial coefficients.

  6. Vertical field and equilibrium calculation in ETE

    International Nuclear Information System (INIS)

    Montes, Antonio; Shibata, Carlos Shinya.

    1996-01-01

    The free-boundary MHD equilibrium code HEQ is used to study the plasma behaviour in the tokamak ETE, with optimized compensations coils and vertical field coils. The changes on the equilibrium parameters for different plasma current values are also investigated. (author). 5 refs., 4 figs., 2 tabs

  7. Equilibrium Droplets on Deformable Substrates: Equilibrium Conditions.

    Science.gov (United States)

    Koursari, Nektaria; Ahmed, Gulraiz; Starov, Victor M

    2018-05-15

    Equilibrium conditions of droplets on deformable substrates are investigated, and it is proven using Jacobi's sufficient condition that the obtained solutions really provide equilibrium profiles of both the droplet and the deformed support. At the equilibrium, the excess free energy of the system should have a minimum value, which means that both necessary and sufficient conditions of the minimum should be fulfilled. Only in this case, the obtained profiles provide the minimum of the excess free energy. The necessary condition of the equilibrium means that the first variation of the excess free energy should vanish, and the second variation should be positive. Unfortunately, the mentioned two conditions are not the proof that the obtained profiles correspond to the minimum of the excess free energy and they could not be. It is necessary to check whether the sufficient condition of the equilibrium (Jacobi's condition) is satisfied. To the best of our knowledge Jacobi's condition has never been verified for any already published equilibrium profiles of both the droplet and the deformable substrate. A simple model of the equilibrium droplet on the deformable substrate is considered, and it is shown that the deduced profiles of the equilibrium droplet and deformable substrate satisfy the Jacobi's condition, that is, really provide the minimum to the excess free energy of the system. To simplify calculations, a simplified linear disjoining/conjoining pressure isotherm is adopted for the calculations. It is shown that both necessary and sufficient conditions for equilibrium are satisfied. For the first time, validity of the Jacobi's condition is verified. The latter proves that the developed model really provides (i) the minimum of the excess free energy of the system droplet/deformable substrate and (ii) equilibrium profiles of both the droplet and the deformable substrate.

  8. Ion exchange equilibrium constants

    CERN Document Server

    Marcus, Y

    2013-01-01

    Ion Exchange Equilibrium Constants focuses on the test-compilation of equilibrium constants for ion exchange reactions. The book first underscores the scope of the compilation, equilibrium constants, symbols used, and arrangement of the table. The manuscript then presents the table of equilibrium constants, including polystyrene sulfonate cation exchanger, polyacrylate cation exchanger, polymethacrylate cation exchanger, polysterene phosphate cation exchanger, and zirconium phosphate cation exchanger. The text highlights zirconium oxide anion exchanger, zeolite type 13Y cation exchanger, and

  9. Quantity Constrained General Equilibrium

    NARCIS (Netherlands)

    Babenko, R.; Talman, A.J.J.

    2006-01-01

    In a standard general equilibrium model it is assumed that there are no price restrictions and that prices adjust infinitely fast to their equilibrium values.In case of price restrictions a general equilibrium may not exist and rationing on net demands or supplies is needed to clear the markets.In

  10. Determination of kinetic and equilibrium parameters of the batch adsorption of Mn(II), Co(II), Ni(II) and Cu(II) from aqueous solution by black carrot (Daucus carota L.) residues

    International Nuclear Information System (INIS)

    Guezel, Fuat; Yakut, Hakan; Topal, Giray

    2008-01-01

    In this study, the effect of temperature on the adsorption of Mn(II), Ni(II), Co(II) and Cu(II) from aqueous solution by modified carrot residues (MCR) was investigated. The equilibrium contact times of adsorption process for each heavy metals-MCR systems were determined. Kinetic data obtained for each heavy metal by MCR at different temperatures were applied to the Lagergren equation, and adsorption rate constants (k ads ) at these temperatures were determined. These rate constants related to the adsorption of heavy metal by MCR were applied to the Arrhenius equation, and activation energies (E a ) were determined. In addition, the isotherms for adsorption of each heavy metal by MCR at different temperatures were also determined. These isothermal data were applied to linear forms of isotherm equations that they fit the Langmuir adsorption isotherm, and the Langmuir constants (q m and b) were calculated. b constants determined at different temperatures were applied to thermodynamic equations, and thermodynamic parameters such as enthalpy (ΔH), free energy (ΔG), and entropy (ΔS) were calculated and these values show that adsorption of heavy metal on MCR was an endothermic process and process of adsorption was favoured at high temperatures

  11. Money Inventories in Search Equilibrium

    OpenAIRE

    Berentsen, Aleksander

    1998-01-01

    The paper relaxes the one unit storage capacity imposed in the basic search-theoretic model of fiat money with indivisible real commodities and indivisible money. Agents can accumulate as much money as they want. It characterizes the stationary distributions of money and shows that for reasonable parameter values (e.g. production cost, discounting, degree of specialization) a monetary equilibrium exists. There are multiple stationary distributions of a given amount of money, which differ in t...

  12. Equilibrium Price Dispersion in a Matching Model with Divisible Money

    NARCIS (Netherlands)

    Kamiya, K.; Sato, T.

    2002-01-01

    The main purpose of this paper is to show that, for any given parameter values, an equilibrium with dispersed prices (two-price equilibrium) exists in a simple matching model with divisible money presented by Green and Zhou (1998).We also show that our two-price equilibrium is unique in certain

  13. Phase equilibrium engineering

    CERN Document Server

    Brignole, Esteban Alberto

    2013-01-01

    Traditionally, the teaching of phase equilibria emphasizes the relationships between the thermodynamic variables of each phase in equilibrium rather than its engineering applications. This book changes the focus from the use of thermodynamics relationships to compute phase equilibria to the design and control of the phase conditions that a process needs. Phase Equilibrium Engineering presents a systematic study and application of phase equilibrium tools to the development of chemical processes. The thermodynamic modeling of mixtures for process development, synthesis, simulation, design and

  14. Equilibrium and generators

    International Nuclear Information System (INIS)

    Balter, H.S.

    1994-01-01

    This work studies the behaviour of radionuclides when it produce a desintegration activity,decay and the isotopes stable creation. It gives definitions about the equilibrium between activity of parent and activity of the daughter, radioactive decay,isotope stable and transient equilibrium and maxim activity time. Some considerations had been given to generators that permit a disgregation of two radioisotopes in equilibrium and its good performance. Tabs

  15. Experimental determination of thermodynamic equilibrium in biocatalytic transamination

    DEFF Research Database (Denmark)

    Tufvesson, Pär; Jensen, Jacob Skibsted; Kroutil, Wolfgang

    2012-01-01

    The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones....... Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore...

  16. Comparison of bone cancer risks in beagle dogs for inhaled plutonium-238 dioxide, inhaled strontium-90 chloride, and injected strontium-90

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, W.C.; Muggenburg, B.A.; Hahn, F.F. [and others

    1995-12-01

    There is a continuing need to understand dose-response relationships for ionizing radiation in order to protect the health of the public and nuclear workers from undue exposures. However, relatively few human populations have been exposed to doses of radiation high enough to cause observable, long-term health effects from which to derive dose-response relationships. This is particularly true for internally deposited radionuclides, although much effort has been devoted to epidemiological studies of the few types of exposures available, including lung cancers in uranium miners form the inhalation of the radioactive decay products of Ra, liver cancers in patients injected with Thorotrast X-ray contrast medium containing Th, bone cancers in radium dial painters who ingested Ra, and bone cancers in patients who received therapeutic doses of Ra. These four types of exposures to internally deposited radionuclides provide a basis for understanding the health effects of many other radionuclides for which a potential for exposure exists. However, potential exposures to internally deposited radionuclides may differ in many modifying factors, such as route of exposure, population differences, and physical, chemical, and elemental forms of radionuclides. The only means available to study many of these modifying factors has been in laboratory animals, and to then extrapolate the results to humans. Three conclusions can be drawn from this example.

  17. Fast determination of strontium-89 and strontium-90 by simultaneous Cerencov- and Proportional-Counting; Schnelle Bestimmung von Strontium-89 und Strontium-90 mittels simultaner Cerenkov- und Proportionalzaehlrohrmessung

    Energy Technology Data Exchange (ETDEWEB)

    Laerbusch, Karin; Wiezorek, Claus [Chemisches und Veterinaeruntersuchungsamt MEL, Muenster (Germany)

    2014-01-20

    The presented method for simultaneous determination of Sr 89 and Sr 90 combines the techniques of Cerencov- and Proportional-Counting. Due to the low limit of detection of the latter technique, the method is very sensitive for the total radiostrontium. The distribution among two measurement devices offers the advantage of time saving.

  18. Quantitative analysis of strontium 90 in the radioactive wastes by means of thenoyltrifluoroacetone; Dosage du strontium 90 dans les effluents radioactifs par le thenoyltrifluoroacetone

    Energy Technology Data Exchange (ETDEWEB)

    Testemale, G; Leredde, J L [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1970-07-01

    A simple method of analysing the quantity of {sup 90}Sr has been perfected. It consists in a double extraction of it by means of thenoyltrifluoroacetone and tributylphosphate in tetrachloride of carbon followed by eliminating yttrium 90 by means of thenoyltrifluoroacetone in the benzene. Numberings on aliquot parts of wastes make the determination of that element possible. The yield is about 97 per cent. (authors) [French] Une technique simple du dosage du {sup 90}Sr a ete mise au point. Elle consiste en une double extraction par le thenoyltrifluoroacetone et le tributylphosphate dans le tetrachlorure de carbone, suivie de l'elimination de l'yttrium 90 par le thenoyltrifluoroacetone dans le benzene, Des comptages sur des parties aliquotes d'effluents permettent la dermination de cet element. Rendement environ 97 pour cent. (auteurs)

  19. Comparison of bone cancer risks in beagle dogs for inhaled plutonium-238 dioxide, inhaled strontium-90 chloride, and injected strontium-90

    International Nuclear Information System (INIS)

    Griffith, W.C.; Muggenburg, B.A.; Hahn, F.F.

    1995-01-01

    There is a continuing need to understand dose-response relationships for ionizing radiation in order to protect the health of the public and nuclear workers from undue exposures. However, relatively few human populations have been exposed to doses of radiation high enough to cause observable, long-term health effects from which to derive dose-response relationships. This is particularly true for internally deposited radionuclides, although much effort has been devoted to epidemiological studies of the few types of exposures available, including lung cancers in uranium miners form the inhalation of the radioactive decay products of Ra, liver cancers in patients injected with Thorotrast X-ray contrast medium containing Th, bone cancers in radium dial painters who ingested Ra, and bone cancers in patients who received therapeutic doses of Ra. These four types of exposures to internally deposited radionuclides provide a basis for understanding the health effects of many other radionuclides for which a potential for exposure exists. However, potential exposures to internally deposited radionuclides may differ in many modifying factors, such as route of exposure, population differences, and physical, chemical, and elemental forms of radionuclides. The only means available to study many of these modifying factors has been in laboratory animals, and to then extrapolate the results to humans. Three conclusions can be drawn from this example

  20. Equilibrium-torus bifurcation in nonsmooth systems

    DEFF Research Database (Denmark)

    Zhusubahyev, Z.T.; Mosekilde, Erik

    2008-01-01

    Considering a set of two coupled nonautonomous differential equations with discontinuous right-hand sides describing the behavior of a DC/DC power converter, we discuss a border-collision bifurcation that can lead to the birth of a two-dimensional invariant torus from a stable node equilibrium...... point. We obtain the chart of dynamic modes and show that there is a region of parameter space in which the system has a single stable node equilibrium point. Under variation of the parameters, this equilibrium may disappear as it collides with a discontinuity boundary between two smooth regions...... in the phase space. The disappearance of the equilibrium point is accompanied by the soft appearance of an unstable focus period-1 orbit surrounded by a resonant or ergodic torus. Detailed numerical calculations are supported by a theoretical investigation of the normal form map that represents the piecewise...

  1. Fall Back Equilibrium

    NARCIS (Netherlands)

    Kleppe, J.; Borm, P.E.M.; Hendrickx, R.L.P.

    2008-01-01

    Fall back equilibrium is a refinement of the Nash equilibrium concept. In the underly- ing thought experiment each player faces the possibility that, after all players decided on their action, his chosen action turns out to be blocked. Therefore, each player has to decide beforehand on a back-up

  2. Nonideal plasmas as non-equilibrium media

    International Nuclear Information System (INIS)

    Morozov, I V; Norman, G E; Valuev, A A; Valuev, I A

    2003-01-01

    Various aspects of the collective behaviour of non-equilibrium nonideal plasmas are studied. The relaxation of kinetic energy to the equilibrium state is simulated by the molecular dynamics (MD) method for two-component non-degenerate strongly non-equilibrium plasmas. The initial non-exponential stage, its duration and the subsequent exponential stage of the relaxation process are studied for a wide range of ion charge, nonideality parameter and ion mass. A simulation model of the nonideal plasma excited by an electron beam is proposed. An approach is developed to calculate the dynamic structure factor in non-stationary conditions. Instability increment is obtained from MD simulations

  3. MHD equilibrium identification on ASDEX-Upgrade

    International Nuclear Information System (INIS)

    McCarthy, P.J.; Schneider, W.; Lakner, K.; Zehrfeld, H.P.; Buechl, K.; Gernhardt, J.; Gruber, O.; Kallenbach, A.; Lieder, G.; Wunderlich, R.

    1992-01-01

    A central activity accompanying the ASDEX-Upgrade experiment is the analysis of MHD equilibria. There are two different numerical methods available, both using magnetic measurements which reflect equilibrium states of the plasma. The first method proceeds via a function parameterization (FP) technique, which uses in-vessel magnetic measurements to calculate up to 66 equilibrium parameters. The second method applies an interpretative equilibrium code (DIVA) for a best fit to a different set of magnetic measurements. Cross-checks with the measured particle influxes from the inner heat shield and the divertor region and with visible camera images of the scrape-off layer are made. (author) 3 refs., 3 figs

  4. Internal equilibrium layer growth over forest

    DEFF Research Database (Denmark)

    Dellwik, E.; Jensen, N.O.

    2000-01-01

    the magnitude of the scatter. Different theoretical friction velocity profiles for the Internal Boundary Layer (IBL) are tested against the forest data. The results yield information on the Internal Equilibrium Layer (IEL) growth and an equation for the IEL height fur neutral conditions is derived. For stable...... conditions the results indicate that very long fetches are required in order to measure parameters in equilibrium with the actual surface....

  5. Determination of gross plasma equilibrium from magnetic multipoles

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, C.E.

    1986-05-01

    A new approximate technique to determine the gross plasma equilibrium parameters, major radius, minor radius, elongation and triangularity for an up-down symmetric plasma is developed. It is based on a multipole representation of the externally applied poloidal magnetic field, relating specific terms to the equilibrium parameters. The technique shows reasonable agreement with free boundary MHD equilibrium results. The method is useful in dynamic simulation and control studies.

  6. Determination of gross plasma equilibrium from magnetic multipoles

    International Nuclear Information System (INIS)

    Kessel, C.E.

    1986-05-01

    A new approximate technique to determine the gross plasma equilibrium parameters, major radius, minor radius, elongation and triangularity for an up-down symmetric plasma is developed. It is based on a multipole representation of the externally applied poloidal magnetic field, relating specific terms to the equilibrium parameters. The technique shows reasonable agreement with free boundary MHD equilibrium results. The method is useful in dynamic simulation and control studies

  7. Equilibrium and non equilibrium in fragmentation

    International Nuclear Information System (INIS)

    Dorso, C.O.; Chernomoretz, A.; Lopez, J.A.

    2001-01-01

    Full text: In this communication we present recent results regarding the interplay of equilibrium and non equilibrium in the process of fragmentation of excited finite Lennard Jones drops. Because the general features of such a potential resemble the ones of the nuclear interaction (fact that is reinforced by the similarity between the EOS of both systems) these studies are not only relevant from a fundamental point of view but also shed light on the problem of nuclear multifragmentation. We focus on the microscopic analysis of the state of the fragmenting system at fragmentation time. We show that the Caloric Curve (i e. the functional relationship between the temperature of the system and the excitation energy) is of the type rise plateau with no vapor branch. The usual rise plateau rise pattern is only recovered when equilibrium is artificially imposed. This result puts a serious question on the validity of the freeze out hypothesis. This feature is independent of the dimensionality or excitation mechanism. Moreover we explore the behavior of magnitudes which can help us determine the degree of the assumed phase transition. It is found that no clear cut criteria is presently available. (Author)

  8. Chemical Principles Revisited: Chemical Equilibrium.

    Science.gov (United States)

    Mickey, Charles D.

    1980-01-01

    Describes: (1) Law of Mass Action; (2) equilibrium constant and ideal behavior; (3) general form of the equilibrium constant; (4) forward and reverse reactions; (5) factors influencing equilibrium; (6) Le Chatelier's principle; (7) effects of temperature, changing concentration, and pressure on equilibrium; and (8) catalysts and equilibrium. (JN)

  9. Equilibrium and non-equilibrium phenomena in arcs and torches

    NARCIS (Netherlands)

    Mullen, van der J.J.A.M.

    2000-01-01

    A general treatment of non-equilibrium plasma aspects is obtained by relating transport fluxes to equilibrium restoring processes in so-called disturbed Bilateral Relations. The (non) equilibrium stage of a small microwave induced plasma serves as case study.

  10. Non-equilibrium Economics

    Directory of Open Access Journals (Sweden)

    Katalin Martinás

    2007-02-01

    Full Text Available A microeconomic, agent based framework to dynamic economics is formulated in a materialist approach. An axiomatic foundation of a non-equilibrium microeconomics is outlined. Economic activity is modelled as transformation and transport of commodities (materials owned by the agents. Rate of transformations (production intensity, and the rate of transport (trade are defined by the agents. Economic decision rules are derived from the observed economic behaviour. The non-linear equations are solved numerically for a model economy. Numerical solutions for simple model economies suggest that the some of the results of general equilibrium economics are consequences only of the equilibrium hypothesis. We show that perfect competition of selfish agents does not guarantee the stability of economic equilibrium, but cooperativity is needed, too.

  11. DIAGNOSIS OF FINANCIAL EQUILIBRIUM

    Directory of Open Access Journals (Sweden)

    SUCIU GHEORGHE

    2013-04-01

    Full Text Available The analysis based on the balance sheet tries to identify the state of equilibrium (disequilibrium that exists in a company. The easiest way to determine the state of equilibrium is by looking at the balance sheet and at the information it offers. Because in the balance sheet there are elements that do not reflect their real value, the one established on the market, they must be readjusted, and those elements which are not related to the ordinary operating activities must be eliminated. The diagnosis of financial equilibrium takes into account 2 components: financing sources (ownership equity, loaned, temporarily attracted. An efficient financial equilibrium must respect 2 fundamental requirements: permanent sources represented by ownership equity and loans for more than 1 year should finance permanent needs, and temporary resources should finance the operating cycle.

  12. Equilibrium statistical mechanics

    CERN Document Server

    Mayer, J E

    1968-01-01

    The International Encyclopedia of Physical Chemistry and Chemical Physics, Volume 1: Equilibrium Statistical Mechanics covers the fundamental principles and the development of theoretical aspects of equilibrium statistical mechanics. Statistical mechanical is the study of the connection between the macroscopic behavior of bulk matter and the microscopic properties of its constituent atoms and molecules. This book contains eight chapters, and begins with a presentation of the master equation used for the calculation of the fundamental thermodynamic functions. The succeeding chapters highlight t

  13. Computing Equilibrium Chemical Compositions

    Science.gov (United States)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  14. Micro Data and General Equilibrium Models

    DEFF Research Database (Denmark)

    Browning, Martin; Hansen, Lars Peter; Heckman, James J.

    1999-01-01

    Dynamic general equilibrium models are required to evaluate policies applied at the national level. To use these models to make quantitative forecasts requires knowledge of an extensive array of parameter values for the economy at large. This essay describes the parameters required for different...... economic models, assesses the discordance between the macromodels used in policy evaluation and the microeconomic models used to generate the empirical evidence. For concreteness, we focus on two general equilibrium models: the stochastic growth model extended to include some forms of heterogeneity...

  15. Immunity by equilibrium.

    Science.gov (United States)

    Eberl, Gérard

    2016-08-01

    The classical model of immunity posits that the immune system reacts to pathogens and injury and restores homeostasis. Indeed, a century of research has uncovered the means and mechanisms by which the immune system recognizes danger and regulates its own activity. However, this classical model does not fully explain complex phenomena, such as tolerance, allergy, the increased prevalence of inflammatory pathologies in industrialized nations and immunity to multiple infections. In this Essay, I propose a model of immunity that is based on equilibrium, in which the healthy immune system is always active and in a state of dynamic equilibrium between antagonistic types of response. This equilibrium is regulated both by the internal milieu and by the microbial environment. As a result, alteration of the internal milieu or microbial environment leads to immune disequilibrium, which determines tolerance, protective immunity and inflammatory pathology.

  16. Equilibrium and out-of-equilibrium thermodynamics in supercooled liquids and glasses

    International Nuclear Information System (INIS)

    Mossa, S; Nave, E La; Tartaglia, P; Sciortino, F

    2003-01-01

    We review the inherent structure thermodynamical formalism and the formulation of an equation of state (EOS) for liquids in equilibrium based on the (volume) derivatives of the statistical properties of the potential energy surface. We also show that, under the hypothesis that during ageing the system explores states associated with equilibrium configurations, it is possible to generalize the proposed EOS to out-of-equilibrium (OOE) conditions. The proposed formulation is based on the introduction of one additional parameter which, in the chosen thermodynamic formalism, can be chosen as the local minimum where the slowly relaxing OOE liquid is trapped

  17. Equilibrium shoreface profiles

    DEFF Research Database (Denmark)

    Aagaard, Troels; Hughes, Michael G

    2017-01-01

    Large-scale coastal behaviour models use the shoreface profile of equilibrium as a fundamental morphological unit that is translated in space to simulate coastal response to, for example, sea level oscillations and variability in sediment supply. Despite a longstanding focus on the shoreface...... profile and its relevance to predicting coastal response to changing environmental conditions, the processes and dynamics involved in shoreface equilibrium are still not fully understood. Here, we apply a process-based empirical sediment transport model, combined with morphodynamic principles to provide......; there is no tuning or calibration and computation times are short. It is therefore easily implemented with repeated iterations to manage uncertainty....

  18. Microeconomics : Equilibrium and Efficiency

    NARCIS (Netherlands)

    Ten Raa, T.

    2013-01-01

    Microeconomics: Equilibrium and Efficiency teaches how to apply microeconomic theory in an innovative, intuitive and concise way. Using real-world, empirical examples, this book not only covers the building blocks of the subject, but helps gain a broad understanding of microeconomic theory and

  19. Differential Equation of Equilibrium

    African Journals Online (AJOL)

    user

    ABSTRACT. Analysis of underground circular cylindrical shell is carried out in this work. The forth order differential equation of equilibrium, comparable to that of beam on elastic foundation, was derived from static principles on the assumptions of P. L Pasternak. Laplace transformation was used to solve the governing ...

  20. Comments on equilibrium, transient equilibrium, and secular equilibrium in serial radioactive decay

    International Nuclear Information System (INIS)

    Prince, J.R.

    1979-01-01

    Equations describing serial radioactive decay are reviewed along with published descriptions or transient and secular equilibrium. It is shown that terms describing equilibrium are not used in the same way by various authors. Specific definitions are proposed; they suggest that secular equilibrium is a subset of transient equilibrium

  1. Strontium-90 and cesium-137 in freshwater; from Oct. 1978 to June 1979

    International Nuclear Information System (INIS)

    1979-01-01

    The samples of fresh water, 100 l each, were collected. The carriers of Sr and Cs were added immediately after the sampling, and the samples were vigorously stirred and filtered, then passed through cation exchange columns. Sr and Cs were eluted with hydrochloric acid from the cation exchange columns. Sr-90 and Cs-137 were separated from the sample solutions by the methods described, and their activities were counted with low background beta counters for 60 min. The net rate of sample counting was corrected for the counter efficiency, recovery, self-absorption and decay. As the environmental data, the results of Sr-90 and Cs-137 in fresh water obtained from October, 1978, to June, 1979, and the locations of sampling are given. In a table, the months and the locations of sampling, pH, and the amounts of Sr-90 and Cs-137 (pCi/l) are shown. The maximum values are 0.39 pCi/l of Sr-90 and 0.09 pCi/l of Cs-137 found in Miho County, Fukui Prefecture, in December, 1978. (Kako, I.)

  2. Strontium-90 and cesium-137 in sea fish (from Nov. 1984 to Jun. 1985)

    International Nuclear Information System (INIS)

    1985-01-01

    Sr-90 and Cs-137 in sea fish were determined using radiochemical analysis. Seven species of fish (Branchiostegus sp., Katsuwonus pelamis, Limanda herzensteini, Sillago sihama, Scomber japonicus, Caesio chrysozonus cuvier, and Sebastes Inermis) were collected during the fishing season from nine sampling locations. Only the edible part was used in cases of larger sized fish, and the whole part was used in cases of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonization, the sample was ashed in an electric muffle furnace. The maximum value of Sr-90 was 0.9 +- 0.26 pCi/kg in Limanda herzensteini collected from Hiroshima in March 1985; and that of Cs-137 was 12 +- 0.5 pCi/kg in Katsuwonus pelamis collected from Kochi in May 1985. (Namekawa, K.)

  3. Measurement of strontium-89 and strontium-90 in environmental waters. A tentative reference method

    International Nuclear Information System (INIS)

    1976-03-01

    A tentative reference method for the measurement of 89 Sr and 90 Sr in environmental waters is described. Samples of environmental water sources are collected, preserved with acid-strontium carrier, and analyzed for 89 Sr and/or 90 Sr. The isotopes are separated from the sample water by precipitating with stable strontium carrier as carbonate. The strontium carbonate is dissolved, 90 Sr separated, the strontium reprecipitated as carbonate, filtered, and counted for the combined 89 Sr and 90 Sr activity. The 90 y is allowed to grow in from the 90 y activity; the strontium carbonate is redissolved; the 90 y is separated, precipitated, and counted for the 90 Sr determination. The 89 Sr activity is then determined by difference of the total 89 Sr and 90 y and the separate 90 Sr activities. Recoveries are determined from the added and found (recovered) strontium carrier. Counting efficiencies are determined with prepared standard reference samples. Results are reported in pCi/liter

  4. Strontium-90 and cesium-137 in soil (from July 1979 to Oct. 1980)

    International Nuclear Information System (INIS)

    1980-01-01

    The samples of soil were collected from the locations in spacious and flat areas without past disturbance on the surfaces. The samples were taken from two layers of different depth, 0 - 5 cm and 5 - 20 cm. In the course of air drying, lumps were crushed by hand, and plant roots, pebbles and small gravels were removed. The air-dried soils were sieved, and heated in the presence of Sr and Cs carriers together with sodium hydroxide. Then the samples were heated with hydrochloric acid, and Sr-90 and Cs-137 were separated from the sample solutions by the methods described. Their activities were counted with low background beta counters. The net rate of sample counting was corrected for the counter efficiency, recovery, self-absorption and decay. As the environmental data, the results of Sr-90 and Cs-137 in soil obtained from July, 1979, to October, 1980, and the locations of sampling are given. In a table, the months, locations and depth (cm) of sampling, air soil (%), Sr(%), and the amounts of Sr-90 and Cs-137 (pCi/kg, mCi/km 2 ) are shown. The maximum values are 120 mCi/km 2 of Sr-90 and 260 mCi/km 2 of Cs-137 found in Kawabe County, Akita Prefecture, in July, 1980. (Kako, I.)

  5. Cesium - 137 and strontium -90 in dairy-milk. First quarter 1981

    International Nuclear Information System (INIS)

    1981-05-01

    Results of mesurements of 137 Cs and 90 Sr activities in milk at 9 dairies in Sweden during the first three months of 1981. Meanvalues for all dairies are: 137 Cs - 0.15 Bq/l, 90 Sr - 0.12 Bq/l. The regional variations are considerable. (L.E.)

  6. Strontium-90 and cesium-137 in total diet; April, 1978 to March, 1979

    International Nuclear Information System (INIS)

    1979-01-01

    Samples should be meals to be eaten daily. Avoid meals specially prepared. One sample should consist of breakfast, lunch, supper, and snacks (tea and water are inclusive) for five persons per day. The stuff is carbonized under direct fire on a large-sized stainless plate. Take care not to raise smoke. The carbide is moved on to a porcelain dish and then ashed at 500 0 C in an electric oven. The results obtained from April 1978 to March 1979 were shown in a table. (J.P.N.)

  7. Strontium-90 and cesium-137 in sea fish from Nov. 1983 to Jun. 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in sea fish were determined using radiochemical analysis. Seven species of fish (Branchiostegus sp., Katsuwonus pelamis, Limanda herzensteini, Sillago sihama, Pneumatophorus japonicus, Caesio chrysozonus cuvier, and Sebastes Inermis) were collected during the fishing season from 8 sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonized, the sample was ashed in an electric muffle furnace. The maximum values of Sr-90 was 1.0+-0.25 pCi/kg in Sebastes Inermis collected from Yamaguchi in April 1984; the maximum value of Cs-137 was 14.0+-0.60 pCi/kg in Katsuwonus pelamis collected from Kochi in May 1984. (Namekawa, K.)

  8. Strontium-90 and cesium-137 in rain and dry fallout; from Jan. 1979 to Jun. 1979

    International Nuclear Information System (INIS)

    1979-01-01

    The samples of rain and dry fallout were collected monthly on the sampling trays with approximately 5000 cm 2 area, which were filled with water to 1 cm depth at the beginning of every month. The samples were filtered after Sr and Cs carriers were added, and passed through cation exchange columns at 80 ml/min. Sr and Cs were eluted with hydrochloric acid from the cation exchange columns. The methods of separating Sr-90 and Cs-137 from the sample solutions are explained, and their activities were counted with low background beta counters for 60 min. The net rate of sample counting was corrected for the counter efficiency, recovery, self-absorption and decay. As the environmental data, the results of Sr-90 and Cs-137 in rain and dry fallout obtained from January to June, 1979, and the locations of sampling are given. In a table, the months and the locations of sampling, duration (days), precipitation (mm), and the amounts of Sr-90 and Cs-137 (mCi/km 2 ) are shown. The maximum values are 0.16 mCi/km 2 of Sr-90 and 0.22 mCi/km 2 of Cs-137 found in Fukui in February, 1979. (Kako, I.)

  9. Strontium-90 and cesium-137 in sea fish (from Jun. 1981 to Dec. 1981)

    International Nuclear Information System (INIS)

    1981-01-01

    90 Sr and 137 Cs in sea fish were determined. Fish was rinsed with water and blotted with a filter paper. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results from June to December 1981 are shown in a table. (Namekawa, K.)

  10. Coefficient of soil decontamination from strontium-90 at the territory of east Ural radioactive trace (EURT)

    International Nuclear Information System (INIS)

    Bazhenov, A.V.; Volobuev, P.V.; Isymov, M.A.

    1996-01-01

    The knowledge of coefficient of soil decontamination is necessary for predictions the dynamics in development of radioactive situation, for retrospective estimation and reconstruction of the initial radioactive contamination levels of territories. By effective coefficient of soil decontamination from radionuclides (CSD) we mean the multiple of a nuclide completely removed from the soil as a result of its physical decay, active removal of radionuclides from the ground into water ecosystems, as well as biogeochemical and wind migration beyond KURT borders. Its dimension can be expressed in the divisible relation (in how many times?), in percentage, as well as in periods of half-desintegration, if the process of desintegration is the exponent. The calculation is made on a complete nuclides supply in soil. The objective of the study is to calculate the effective coefficient of soil decontamination from 90 Sr on the basis of the analyzis of the experimental materials received at KURT territories in Sverdlovsk region. (author)

  11. Strontium-90 in human bone: 1981 results for New York City and San Francisco

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1982-01-01

    Results are presented of determinations of Sr-90 content of 102 specimens of vertebrae obtained during 1981 in New York City and San Francisco. The average Sr-90 to Ca ratios for adult vertebrae are 0.95 pCi/g Ca (0.037 Bq/g Ca) in New York and 0.61 pCi/g Ca (0.023 Bq/g Ca) in San Francisco, little changed from the average values of the previous year. Average Sr-90 concentrations in children's bone are now little different from the adult values. A two compartment bone model, which accounts for both short and long term retention of Sr-90 in bone, is used to describe the variations of Sr-90 content of bone and provide correlation with dietary Sr-90 intake. Regression analysis of the 21 years of survey data provides values of the relative retention of dietary Sr-90 and the effective bone turnover rates. The bone model gives satisfactory description of observed Sr-90 levels and allows reliable assessment of the long-term behavior of Sr-90 in man

  12. Strontium-90 in human bone: 1980 results for New York City and San Francisco

    International Nuclear Information System (INIS)

    Klusek, C.S.

    1981-01-01

    Results are presented of determinations of 90 Sr content of 75 specimens of vertebrae obtained during 1980 in New York City and San Francisco. The average 90 Sr to Ca ratios for adult vertebrae are 0.95 pCi/g Ca (0.037 Bq/g Ca) in New York and 0.60 pCi/g Ca (0.022 Bq/g Ca) in San Francisco, little changed from the average values of the previous year. Average 90 Sr concentrations in children's bone are now little different from the adult values. A two compartment bone model, which accounts for both short and long term retention of 90 Sr in bone, is used to describe the variations of 90 Sr content of bone and provide correlation with dietary 90 Sr intake. Regression analysis of the 20 years of survey data provides values of the relative retention of dietary 90 Sr and the effective bone turnover rates. The bone model gives satisfactory description of observed 90 Sr levels and allows reliable assessment of the long-term behavior of 90 Sr in man

  13. Comparative toxicity of strontium-90 and radium-226 in beagle dogs

    International Nuclear Information System (INIS)

    Raabe, O.G.; Culbertson, M.R.; White, R.G.; Spangler, W.L.; Cain, G.R.; Parks, N.J.; Samuels, S.J.

    1990-01-01

    The authors are completing a 30-year study of the biologic effects of 90 Sr and 226 Ra in the beagle in order to predict the possible long-term hazards to people from chronic exposure to low levels of irradiation. Animals received either radionuclide by several means of administration: (a) continual ingestion of 90 Sr, (b) a single intravenous injection of 90 Sr, or (c) a series of eight intravenous injections of 226 Ra. Although administration of 90 Sr and 226 Ra ended at 540 days of age, the animals continued to receive chronic, low-level radiation doses from these bone-seeking radionuclides throughout life. This project is the largest single cohort study in beagles of internally deposited radionuclides. It is unique in use of the ingestion route for 90 Sr and in exposures that began before birth and continued throughout development to adulthood with uniform labeling of the skeletons with 90 Sr. The last of the dogs died in 1986 at age 18.5, but the authors are continuing to investigate the significance of these long-term exposures given at low dose rates with regard to cancer production, physiologic well-being, and shortening of life through the detailed records that were kept and by study of preserved materials. All the data have been successfully accumulated and entered into a main-frame computer data base management system. Current work is exclusively directed at preparing research papers summarizing the results and the associated biostatistical and survival analyses

  14. Comparative toxicity of strontium-90 and radium-226 in beagle dogs

    International Nuclear Information System (INIS)

    Raabe, O.G.; Culbertson, M.R.; White, R.G.; Spangler, W.L.; Cain, G.R.; Parks, N.J.; Samuels, S.J.

    1991-01-01

    The authors are completing a 30-year study of the biological effects of 90 Sr and 226 Ra in the beagle in order to predict the possible long-term hazards to people from chronic exposure to low levels of irradiation. Animals received either radionuclide by several means of administration: (a) continual ingestion of 90 Sr, (b) a single intravenous injection of 90 Sr, or (c) a series of eight intravenous injections of 226 Ra. Although administration of 90 Sr and 226 Ra ended at 540 days of age, the animals continued to receive chronic, low-level radiation doses from these bone-seeking radionuclides throughout life. This project is the largest single cohort study in beagles of internally deposited radionuclides. It is unique in use of the ingestion route for 90 Sr and in exposures that began before birth and continued throughout development to adulthood with uniform labeling of the skeletons with 90 Sr. The last of the dogs died in 1986 at age 18.5 years, but the authors are continuing to investigate the significance of these long-term exposures given at low dose rates with regard to cancer production, physiologic well-being, and shortening of life through the detailed records that were kept and by study of preserved materials. All the data have been successfully accumulated and entered into a main-frame computer data base management system. Current work is exclusively directed at preparing research papers summarizing the results and the associated biostatistical and survival analyses

  15. Strontium-90 and cesium-137 in total diet from Oct. 1983 to Jul. 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in total diet were determined using radiochemical analysis. A full one day ordinary diet including three meales, water, tea, and other in-between snacks for five persons was collected as a sample of ''total diet'' from 29 sampling locations. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transfered to a porcelain dish and then ashed at 500 0 C in an electric muffle furnace. The maximum values of Sr-90 and Cs-137 were 5.8+-0.47 pCi.p -1 .d -1 and 19.0+-0.60 pCi.p -1 .d -1 in total diet collected from Akita in July 1984. (Namekawa, K.)

  16. Strontium-90 and cesium-137 in total diet (from Jun. 1983 to Dec. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Sr-90 and Cs-137 in total diet were determined using radiochemical analysis. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 27 sampling locations. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transfered to a porcelain dish and then ashed at 500 0 C in an electric muffle furnace. The maximum values of Sr-90 and Cs-137 in total diet were 5.4 +- 0.43 pCi.p -1 .d -1 from Kochi in November 1983 and 5.5 +- 0.32 pCi.p -1 .d -1 from Akita in November 1983, respectively. (Namekawa, K.)

  17. Strontium-90 and cesium-137 in total diet; from June 1980 to Dec. 1980

    International Nuclear Information System (INIS)

    1980-01-01

    A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet''. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transferred to a porcelain dish and then ashed at 500 0 C in an electric muffle furnace. The results obtained from June 1980 to December 1980 were shown in a table. (J.P.N.)

  18. Strontium-90 and cesium-137 in total diet; from Nov. 1978 to Dec. 1979

    International Nuclear Information System (INIS)

    1980-01-01

    A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet''. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transferred to a porcelain dish and then ashed at 500 0 C in an electric muffle furnace. The results obtained from November 1978 to December 1979 were shown in a table. (J.P.N.)

  19. Strontium-90 and cesium-137 in total diet (from Jun. 1984 to Dec. 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in total diet were determined using radiochemical analysis. A full one ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 20 sampling locations. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transferred to a porcelain dish and then ashed at 500 deg C in an electric muffle furnace. The maximum values of Sr-90 and Cs-137 in total diet were 5.3 +- 0.47 pCi · p -1 · d -1 and 5.4 +- 0.38 pCi · p -1 · d -1 , respectively, from Hokkaido in December 1984. (Namekawa, K.)

  20. Strontium-90 and cesium-137 in total diet (from Jun. 1981 to Dec. 1981)

    International Nuclear Information System (INIS)

    1981-01-01

    90 Sr and 137 Cs in total diet were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet''. The results from June to December 1981 are shown in a table. (Namekawa, K.)

  1. Strontium-90 and cesium-137 in total diet (from Oct. 1984 to Jul. 1985)

    International Nuclear Information System (INIS)

    1985-01-01

    Sr-90 and Cs-137 in total diet were determined using radiochemical analysis. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 27 sampling locations. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transferred to a porcelain dish and then ashed at 500 deg C in an electric muffle furnace. The maximum values of Sr-90 and Cs-137 in total diet were 4.5 +- 0.43 pCi/p·d from Niigata in June 1985 and 4.9 +- 0.40 pCi/p·d from Fukushima in January 1985, respectively. (Namekawa, K.)

  2. Strontium-90 and cesium-137 in total diet; October, 1977 to March, 1978

    International Nuclear Information System (INIS)

    1979-01-01

    Samples should be meals to be eaten daily. Avoid meals specially prepared. One sample should consist of breakfast, lunch, supper, and snacks (tea and water are inclusive) for five persons per day. The stuff is carbonized under direct fire on a large-sized stainless plate. Take care not to raise smoke. The carbide is moved on to a porcelain dish and then ashed at 500 0 C in an electric oven. The results obtained from October 1977 to March 1978 were shown in a table. (J.P.N.)

  3. Strontium-90 and cesium-137 in total diet; from Aug. 1979 to Jul. 1980

    International Nuclear Information System (INIS)

    1980-01-01

    A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet''. The sample in a large stainless steel pan was carbonized carefully by direct application of gas flame, and was transferred to a porcelain dish and then ashed at 500 0 C in an electric muffle furnace. The results obtained from August 1979 to July 1980 were shown in a table. (J.P.N.)

  4. Strontium-90 and cesium-137 in rice (producing districts) from Nov. 1983 to Jan. 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in rice were determined using radiochemical analysis. Polished rice was collected in three producing districts at the harvest and in nine consuming areas when new crops were first put on sale. The sample was carbonized and ashed in a porcelain dish. The maximum value of Sr-90 was 0.40+-0.14 pCi/kg in rice collected from Yamaguchi in November 1983; the maximum value of Cs-137 was 0.3+-0.12 pCi/kg in rice collected from Yamaguchi in November 1983 and from Fukuoka in December 1983. (Namekawa, K.)

  5. Study of the correlation between radioactive contamination of milk and forage with strontium 90

    Energy Technology Data Exchange (ETDEWEB)

    Sabo, A; Mezei, I [Joint Inst. for Nuclear Research, Dubna (USSR). Lab. of Neutron Physics

    1978-08-01

    Significant correlation between radioactive contamination of milk and forage is established on the basis of the data mathematic treatment. Contamination of cow milk by /sup 90/Sr is approximately one order less than forage contamination, which testifies to high discrimination ability of cows in biological chain soil-plant-animal-man. Animals have this ability only in relation to /sup 90/Sr. For other radioactive isotopes discirmination factor can differ significantly from the one characteristic of /sup 90/Sr. It is stressed that as a result of high discrimination ability of cows /sup 90/Sr quantity, penetrating into human body from vegetable products is much more, than the one penetrating from milk and milk products.

  6. Analysis of strontium-90 in the bones of brown trout (Salmo trutta) from Lake Ontario

    International Nuclear Information System (INIS)

    Manos, C.G. Jr.; Kinney, R.M.; Lisk, D.J.

    1993-01-01

    Radionuclides such as Sr-90, mainly from liquid effluent releases from nuclear power generating facilities, can contaminate water and biota. Lake Ontario ultimately receives the outflow from each of the other Great Lakes. In the work reported, brown trout (Salmo trutta) were captured from Lake Ontario and their entire skeletal bone material analyzed for Sr-90. They showed an average concentration of Sr-90 approximately four times greater than control brown trout captured from nearby Cayuga Lake in Central New York State which has no nuclear generating facilities. The results are discussed considering fallout and hydrographic considerations. (author)

  7. PROBLEMS OF PROTECTION OF URBAN AREAS FROM RADIONUCLIDES STRONTIUM-90 AND CAESIUM-137 AFTER TECHNOLOGICAL DISASTERS

    Directory of Open Access Journals (Sweden)

    Olga Cheremisina

    2017-05-01

    Full Text Available The methods of decontamination of radionuclides from soils are considered. The literature focuses on fixing radionuclides in soils and creating geochemical barriers that it is prevent the spread of pollution. The main disadvantage of these methods is exclude the possibility of building a territory. It is need to clean up the area to the sanitary and hygienic requirements for further use and then it is desirable to fix the residual activity. Carried out an analysis of forms of radionuclides fixation in soils and mechanics of this fixation, therewith revealed that Cs-137 fixed more strongly on mineral component of soil, than Sr-90, which is mainly in the acid-soluble and exchangeable form, and, as a consequence, passes into the liquid phase during soil deactivation more easily. Contaminated soil deactivation in the urbanized territory is possible by washing it by ferric chloride solution at a concentration 0.02-0.05 M and with an equimolar addition of an ammonium chloride. Therewith most efficient methods, which used in-situ conditions, are heap and convection leaching technologies with treatment degree, which not less than 80%. At the same time, the most efficient methods which used in-situ conditions are heap and the convection leaching. The hardware-technological scheme of a convection leaching is presented. Noted that ammonium salts additions slightly rising coefficient of treatment from Sr-90. Because ammonium salts aren’t expensive, their additions allow to obtain significant economic benefits due to decreasing of ferric chloride consumption, which is more valuable, and waste water volume reduction.

  8. Strontium-90 in Canada goose eggshells: Nonfatal monitoring for contamination in wildlife

    International Nuclear Information System (INIS)

    Rickard, W.H.; Eberhardt, L.E.

    1990-01-01

    90 Sr was measured in eggshells from Canada geese (Branta canadensis moffitti) that nested on Columbia River islands up- and downstream from deactivated plutonium production reactors on the U.S. Department of Energy's Hanford Site in southeastern Washington. We also measured 90 Sr in wing bones of goose carcasses. Background levels of 90 Sr were based on eggshells collected on an island upstream of the reactors. A few eggshells collected from nests on a single island downstream of the reactors had slightly higher than background levels of 90 Sr. This may have resulted from geese eating shoreline plants or crops irrigated with Columbia River water that contained 90 Sr released into the river through groundwater seepage

  9. Fast and effective determination of strontium-90 in high volumes water samples

    International Nuclear Information System (INIS)

    Basarabova, B.; Dulanska, S.

    2014-01-01

    A simple and fast method was developed for determination of 90 Sr in high volumes of water samples from vicinity of nuclear power facilities. Samples were taken from the environment near Nuclear Power Plants in Jaslovske Bohunice and Mochovce in Slovakia. For determination of 90 Sr was used solid phase extraction using commercial sorbent Analig R Sr-01 from company IBC Advanced Technologies, Inc.. Determination of 90 Sr was performed with dilute solution of HNO 3 (1.5-2 M) and also tested in base medium with NaOH. For elution of 90 Sr was used eluent EDTA with pH in range 8-9. To achieve fast determination, automation was applied, which brings significant reduction of separation time. Concentration of water samples with evaporation was not necessary. Separation was performed immediately after filtration of analyzed samples. The aim of this study was development of less expensive, time unlimited and energy saving method for determination of 90 Sr in comparison with conventional methods. Separation time for fast-flow with volume of 10 dm 3 of water samples was 3.5 hours (flow-rate approximately 3.2 dm 3 / 1 hour). Radiochemical strontium yield was traced by using radionuclide 85 Sr. Samples were measured with HPGe detector (High-purity Germanium detector) at energy E φ = 514 keV. By using Analig R Sr-01 yields in range 72 - 96 % were achieved. Separation based on solid phase extraction using Analig R Sr-01 employing utilization of automation offers new, fast and effective method for determination of 90 Sr in water matrix. After ingrowth of yttrium samples were measured by Liquid Scintillation Spectrometer Packard Tricarb 2900 TR with software Quanta Smart. (authors)

  10. Strontium-90 and cesium-137 in milk (consuming districts) from May 1983 to May 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in milk from consuming districts were determined using radiochemical analysis. Commercial milk was purchased from 26 sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum value of Sr-90 was 2.3+-0.30 pCi/l in milk purchased from Fukushima in May 1983; the maximum value of Cs-137 was 3.3+-0.25 pCi/l in milk purchased from Tottori in February 1984. (Namekawa, K.)

  11. Lifetime effects of long-term exposures to strontium-90 and radium-226 in beagle dogs

    International Nuclear Information System (INIS)

    Book, S.A.; Rosenblatt, L.S.; Goldman, M.

    1986-01-01

    Graded doses of injected 226 Ra or ingested 90 Sr were given to 804 beagles in early life. The median survival times of the various irradiated groups at higher exposures were lower than the control value of 14.7 years. The 226 Ra group with the highest total skeletal dose had a median survival of 4.5 years. For 90 Sr the highest group had a median survival of 2.2 years. Normal life spans were evident in treatment groups with average skeletal doses of 226 Ra or of 2600 rads from 90 Sr. The life-shortening effects of 226 Ra and 90 Sr are related to the tumors produced from the radionuclide exposure. The significant causes of death among the 226 Ra-treated beagles were primary bone cancers, mostly osteosarcomas. Among dogs exposed to 90 Sr, significant numbers of deaths were from primary bone cancer, myeloproliferative disease, and squamous-cell carcinoma of the gingiva. In general, more of these effects were produced in the groups receiving higher doses and dose rates; at lower doses the effects, when present, appeared later than they did at higher doses. 9 refs., 6 figs., 4 tabs

  12. Alterations of bone skeleton structure in connection with strontium-90 incorporation

    International Nuclear Information System (INIS)

    Rodionova, N.V.; Mazhuga, P.M.; Domashevskaya, E.I.; Gorskij, B.A.; Nakorenok, G.B.

    1994-01-01

    By using the methods of histology, electron microscopy and radiochemistry studied the bone skeleton state of animals (mouse like rodents and minks) which live in the 30 km zone of the ChNPP.It was defined contents of 90 Sr, 137 Cs, 134 Cs in the bones during 1989-1993 years. There were described changes in histostructure of the periost endost and bone compact of the tubular bones and also in metaepiphyzal growth plate. The mechanisms of the revealed alterations are discussed

  13. Strontium-90 and cesium-137 in sea water; April, 1978 to March, 1979

    International Nuclear Information System (INIS)

    1979-01-01

    The samples of rain and dry fallout, air-borne dust, service water and fresh water, soil, sea water, sea sediment, total diet, rice, milk, vegetables, tea, fish, shellfishes and seaweed, and fresh water fishes, their sampling and prior treatment are described. The methods of separating Sr-90 and Cs-137 and their measurement are explained. The estimations of stable Sr, K and Ca are made by atomic absorption spectroscopy, flame spectrophotometry and potassium permanganate titration, respectively. The general plan of radioactivity survey in Japan is shown. As the environmental data, the results of Sr-90 and Cs-137 in sea water obtained from April, 1978, to March, 1979, and the locations of sampling are given. In a table, the months and the locations of sampling, Cl (%), sample volume analyzed (l), and the amounts of Sr-90 and Cs-137 (pCi/l) are shown. The maximum values are 0.21 pCi/l of Sr-90 found in Osaka Bay in August, 1978, and 0.19 pCi/l of Cs-137 off Niigata Port in July, 1978. (Kako, I.)

  14. Strontium 90 content in bone samples of deer and domestic animals

    International Nuclear Information System (INIS)

    Kostadinov, K.; Pozhinarova, M.

    1993-01-01

    A comparative radioecological determination of 90 Sr content in leg bone samples of wild deer from Bulgaria (Veliko Tyrnovo), rain deer from Finland (Lapland) and domestic cows and pigs from Bulgaria have been carried out. The study includes four Finish rain deer, three of them 1-5 Y old, shut in 1991, and one - 13.5 Y old, shut in 1974, two Bulgarian deer, 5-6 Y old, shut in 1991, two cows and a pig killed in 1991. The samples have been prepared by a standard procedure. The fumic nitric acid method has been used for chemical separation of 90 Sr, and a low background beta plastic scintillation device - for counting, The results show that the contamination effect is better expressed in the wild animals due to their specific open air manner of life. The 90 Sr activities vary from 41,5 to 136.9 Bq/kg bone in the Bulgarian deer, from 219.5 to 386.1 Bq/kg bone in the three younger Finish deer, and from 1921.0 to 1967.9 Bq/kg bone in the oldest rain deer. The higher 90 Sr values in the samples of the Finish deer can be connected with the specific trophic chain of these animals and the important role in it of lichen. The quantity of 90 Sr in the investigated pig is 10-20 times lower than its content in the deer (2.1 - 4.4 Bq/kg bone). It is explained with the pig's age (10 months old) and the diet based on food grown about 5 years after Chernobyl. There is no significant difference in 90 Sr content of the cows' and deer's samples. This is due to their very similar zoological systems of eating and similar trophic chains (open pasture). The data obtained show a good reproducibility proved by the similar values of the radiochemical yields achieved (60-70%) in each of the analysis made. 1 tab., 1 refs

  15. Method validation to measure Strontium-90 in urine sample for internal dosimetry assessment

    International Nuclear Information System (INIS)

    Bitar, A.; Maghrabi, M.; Alhamwi, A.

    2010-12-01

    Occupational individuals exposed at some scientific centers in Syrian Arab Republic to potentially significant intake by ingestion or inhalation during process of producing radiopharmaceutical compounds. The received radioactive intake differs in relation to the amount of radionuclides released during the preparation processes, to the work conditions and to the applying ways of the radiation protection procedures. TLD (Thermoluminescence Dosimeter) is usually used for external radiation monitoring for workers in radioisotope centers. During the external monitoring programme, it was noticed that some workers were exposed to high external dose resultant from radiation accident in their laboratory when preparing Y-90 from Sr-90. For internal dose assessment, chemical method to measure the amount of Sr-90 in urine samples was validated and explained in details in this study. Urine bioassays were carried out and the activities of 90 Sr were determined using liquid scintillation counter. Then, the validated method was used for internal occupational monitoring purposes through the design of internal monitoring programme. The programme was established for four workers who are dealing, twice per month, with an amount of about 20 mCi in each time. At the beginning, theoretical study was done to assess maximum risks for workers. Calculated internal doses showed that it is necessary to apply internal routine monitoring programme for those workers. (author)

  16. A Rapid Method for Measuring Strontium-90 Activity in Crops in China

    Science.gov (United States)

    Pan, Lingjing Pan; Yu, Guobing; Wen, Deyun; Chen, Zhi; Sheng, Liusi; Liu, Chung-King; Xu, X. George

    2017-09-01

    A rapid method for measuring Sr-90 activity in crop ashes is presented. Liquid scintillation counting, combined with ion exchange columns 4`, 4"(5")-di-t-butylcyclohexane-18-crown-6, is used to determine the activity of Sr-90 in crops. The yields of chemical procedure are quantified using gravimetric analysis. The conventional method that uses ion-exchange resin with HDEHP could not completely remove all the bismuth when comparatively large lead and bismuth exist in the samples. This is overcome by the rapid method. The chemical yield of this method is about 60% and the MDA for Sr-90 is found to be 2:32 Bq/kg. The whole procedure together with using spectrum analysis to determine the activity only takes about one day, which is really a large improvement compared with the conventional method. A modified conventional method is also described here to verify the value of the rapid one. These two methods can meet di_erent needs of daily monitoring and emergency situation.

  17. Absorption and distribution of strontium 90 and cesium 137 in wheat taken from a contaminated soil

    International Nuclear Information System (INIS)

    Argiero, L.; Del Corso, G.; Manfredini, S.; Palmas, G.

    In order to study the sorption of 90 Sr and 137 Cs by wheat at different stages of growth, some seeds have been sown in little cases filled with earth materials containing various quantities of Ca and K. At different stages of growth, the earth materials containing various quantities of Ca have been contaminated with 90 Sr, the earth materials containing different quantities of K have been contaminated with 137 Cs. At the same time plant samples were taken at different stages of their growth, and their radioactivity was measured

  18. Strontium-90 and cesium-137 in milk (consuming districts) (from Aug. 1984 to May 1985)

    International Nuclear Information System (INIS)

    1985-01-01

    Sr-90 and Cs-137 in milk from consuming districts were determined using radiochemical analysis. Commercial milk was purchased from 26 sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum value of Sr-90 was 2.9 +- 0.28 pCi/l in milk purchased from Hokkaido in February 1985; that of Cs-137 was 3.7 +- 0.27 pCi/l in milk purchased from Fukui in February 1985. (Namekawa, K.)

  19. Strontium-90 and cesium-137 in milk (consuming districts) (from May. 1983 to Dec. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Sr-90 and Cs-137 in milk from consuming districts were determined using radiochemical analysis. Commercial milk was purchased from 22 sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 was 5.2 +- 0.37 pCi/l in milk purchased from Akita in August 1983; that of Cs-137 was 5.9 +- 0.32 pCi/l in milk purchased from Kagoshima in August 1983. (Namekawa, K.)

  20. Accumulation of cesium-137 and strontium-90 in ponderosa pine and monterey pine seedlings

    International Nuclear Information System (INIS)

    Entry, J.A.; Rygiewicz, P.T.; Emmingham, W.H.

    1993-01-01

    Because ponderosa pine Pinus ponderosa and Monterey pone (P. radiata D Don) have exceptionally fast growth rates and their abscised needles are not readily dispersed by wind, these species may be valuable for removing radioisotopes from contaminated soils. Ponderosa and Monterey pine seedlings were tested for their ability to accumulate 137 Cs and 90 Sr-characteristic radioisotopes of nuclear fallout-from contaminated soil. Seedlings were grown for 3 mo in 165 cm 3 sphagnum peat moss/perlite (1:1 V/V) in a growth chamber. In Exp. 1, seedling accumulation of 137 Cs and 90 Sr after 1 mo of exposure was measured. In Exp. 2, seedling accumulation of the radioisotopes during different-length exposures was measured. Seedling accumulation of 137 CS and 90 Sr at different concentrations of the radioisotopes in the growth medium was measured in Exp. 3. Ponderosa pine accumulated 6.3% of the 137 Cs and I.5% of the 90 Sr present in the growth medium after 1 mo; Monterey pine accumulated 8.3% of the 137 Cs and 4.5% of the 90 Sr. Accumulation of 137 Cs and 90 Sr by both coniferous species was curvilinearly related to duration of exposure. Accumulation of 137 Cs and 90 Sr by both species increased with increasing concentration in the growth medium and correlated curvilinearly with radioisotope concentration in the growth medium. Large areas throughout the world are contaminated with 137 Cs and 90 Sr as a result of nuclear weapons testing or atomic reactor accidents. The ability of trees to sequester and store 137 Cs and 90 Sr introduces the possibility of using reforestation to remediate contaminated soils

  1. Selected radionuclides. Tritium, carbon-14, krypton-85, strontium-90, iodine, caesium 137, radon, plutonium

    International Nuclear Information System (INIS)

    1983-01-01

    The release of radioactive materials to the environment potentially exposes populations to ionizing radiation and increases the risk of incurring deleterious health effects. The associations of released amounts to effects establish the health criteria for radionuclides. This report provides background information in establishing such health criteria for 14 C, 85 Kr, 90 Sr, 137 Cs, Radon, Plutonium, Iodine and Tritium, including environmental behaviour, sources, transport to man and dosimetry. A brief summary of the general aspects of radiation effects and of radiation protection considerations is presented

  2. Separation and Species Characterization of Complex Compound of Yttrium-90 and Strontium-90 by Paper Electrophoresis

    International Nuclear Information System (INIS)

    Sulaiman; Adang Hardi G; Noor Anis Kundari

    2007-01-01

    The research for species characterization of 90 Y and 90 Sr complex compound have been conducted using variation of buffer, concentration of HCl, electrophoresis operation voltage, time of electrophoresis, and electrophoresis migration media. From many trials, the conclusions are the applicable buffer are tartrate buffer and citrate buffer. These buffers can make a complex compound of 90 Y and there is migration to the anode. But, 90 Sr can’t make any complex compound and migration to the cathode. The optimum concentration of hydrochloride acid is 8 M with tartrate buffer but for citrate buffer, the concentration HCl is 2 M. The hydrochloric acid is used to dissolved the both elements as the mentioned above, but also for making complex ligand. The optimum electrophoresis operation voltage is 200 Volt for the both buffer solution and the duration of electrophoresis operation is 2.5 hours with using tartrate buffer but for citrate buffer the duration is 2 hours. The media of migration which can be used for replacing paper is silica. (author)

  3. Accumulation of strontium-90 and cesium-137 in a number of hydrobionts

    Energy Technology Data Exchange (ETDEWEB)

    Boyadzhiev, A; Keslev, D; Kerteva, A; Novakova, E

    1975-01-01

    Accumulation factors for Sr-90 and Cs-137 are given for a number of plants and fish taken from fresh-water bodies and from the Black Sea. The best indicators for following radioactive, Sr-90 contamination in fresh-water bodies are: Lemna minor and Subularia aquatica among the plants, while Tinca tinca L, Cyprinus carpio L and Cavassius carassius L are the most suitable among the fish for Sr-90. With respect to cesium-137 the most suitable as indicators are Sparganum affine and Subularia aquatica from the plants and Salmo trutta morpha fario L and Cyprinus carpio L. from the fishes. Among the saltwater hydrobionts as indicators of Sr-90 and Cs-137 water contamination the fish Sarda sarda L takes first place, and the plants Cystoseira barbata and Zostera marina take second place. 1 table, 6 refs. (SJR)

  4. Strontium-90 and cesium-137 in tea (Japanese tea); from May 1980 to Jun. 1980

    International Nuclear Information System (INIS)

    1980-01-01

    Five hundred grams of manufactured green tea was collected, carbonized and ashed in a stainless steel pan or a porcelain dish. The results obtained from May 1980 to June 1980 were shown in a table. (J.P.N.)

  5. Strontium-90 concentrations in human teeth in South Ukraine, 5 years after the Chernobyl accident

    International Nuclear Information System (INIS)

    Kulev, Y.D.; Polikarpov, G.G.; Prigodey, E.V.; Assimakopoulos, P.A.

    1994-01-01

    Approximately 1000 human teeth, collected in South Ukraine, in 1990-1991, were measured for 90 Sr concentration. The teeth were grouped into 18 samples according to the age and sex of the donors. Measured levels of 90 Sr concentrations were lower by a factor of 10 than measurements taken in the mid-1960s and mid-1970s. An interesting feature of the data is a 3-fold enhancement of contamination levels in the 25-45 year-old age group of the male population. A possible explanation for this anomaly is that this age group contains a significant number of men who were mobilized immediately after the Chernobyl accident for clean-up operations within the 30-km zone around the damaged nuclear power plant

  6. Simplified method for the determination of strontium-90 in large amounts of bone-ash

    International Nuclear Information System (INIS)

    Patti, F.; Jeanmaire, L.

    1966-06-01

    The principle of the determination is based on a 3-step process: 1) concentrating the strontium by attacking the ash with nitric acid; 2) elimination of residual phosphoric ions by a double precipitation of strontium oxalate; and 3) extraction of yttrium 90, counted in the oxalate form. The advantages of the method: -) using simple techniques it makes it possible to process 50 g of ash; -) the initial concentration of strontium considerably reduces the volume of the solutions as well as the size of precipitates handled. Fuming nitric acid is used in a specially designed burette. (authors) [fr

  7. Strontium-90 and cesium-137 in soil; April, 1977 to September, 1977

    International Nuclear Information System (INIS)

    1979-01-01

    The samples of rain and dry fallout, air-borne dust, service water and fresh water, soil, sea water, sea sediment, total diet, rice, milk, vegetables, tea, fish, shellfishes and sea weed, and fresh water fishes, their sampling and prior treatment are described. The methods of separating Sr-90 and Cs-137 and their measurement are explained. The estimations of stable Sr, K and Ca are made by atomic absorption spectroscopy, flame spectrophotometry and potassium permanganate titration, respectively. The general plan of radioactivity survey in Japan is shown. As the environmental data, the results of Sr-90 and Cs-137 in soil obtained from April to September, 1977, and the locations of sampling are given. In a table, the months, the locations and the depth of sampling, air soil (%), Sr(%) and the amounts of Sr-90 and Cs-137 (pCi/kg or mCi/km 2 ) are shown. The maximum values are 55 mCi/km 2 of Sr-90 and 150 mCi/km 2 of Cs-137 found in Obama, Nagasaki Prefecture, in July, 1977. (Kako, I.)

  8. Rapid and simultaneous determination of Strontium-89 and Strontium-90 in seawater.

    Science.gov (United States)

    Tayeb, Michelle; Dai, Xiongxin; Sdraulig, Sandra

    2016-03-01

    A rapid method has been developed for the direct determination of radiostrontium ((89)Sr and (90)Sr) released in seawater in the early phase of an accident. The method employs a fast and effective pre-concentration of radiostrontium by Sr-Ca co-precipitation followed by separation of radiostrontium using extraction chromatography technique. Radiostrontium is effectively separated in the presence of excessive dominant salts of seawater. Čerenkov and liquid scintillation assay (LSA) techniques are used to determine (89)Sr and (90)Sr. Sample preparation time is approximately 4 h for a set of 10 samples. The method was validated using spiked seawater samples at various activity ratios of (89)Sr:(90)Sr ranging from 1:10 to 9:1. The mean chemical recovery of Sr was 85 ± 3%. (90)Sr showed variable relative bias which enhanced with increasing ratio of (89)Sr:(90)Sr and was in the range ± 21%. The highest biases of (90)Sr determination were due to lower activity concentrations of (90)Sr and are regarded as acceptable in emergency situations with elevated levels of radiostrontium in the sample. The minimum detectable concentration (MDC) of (90)Sr and (89)Sr varied at different (89)Sr:(90)Sr ratios. For 0.1 L seawater and 15 min counting time on a low background Hidex liquid scintillation counter (LSC), the MDC of (90)Sr was in the range of 1.7-3.5 Bq L(-1) and MDC of (89)Sr was in the range 0.5-2.4 Bq L(-1). Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Pituitary inactivation by intrapituitary strontium 90 irradiation with cancer of the breast with generalized metastases

    Energy Technology Data Exchange (ETDEWEB)

    Kayser, I

    1973-09-24

    Pituitary inactivation by intrapituitary Sr/sup 90/ irradiation was carried out on ten female patients with cancer of the breast with generalized metastases by the paranasal, transethmoido-sphenoidal way. The applied dose was 40,000 rad at 4 mm from the surface of the applicators. A direct relation between free interval, remission frequency and survival time could be observed. The remission time was longer with increasing age.

  10. Design and qualification testing of a strontium-90 fluoride heat source

    International Nuclear Information System (INIS)

    Fullam, H.T.

    1981-12-01

    The Strontium Heat Source Development Program began at the Pacific Northwest Laboratory (PNL) in 1972 and is scheduled to be completed by the end of FY-1981. The program is currently funded by the US Department of Energy (DOE) By-Product Utilization Program. The primary objective of the program has been to develop the data and technology required to permit the licensing of power systems for terrestrial applications that utilize 90 SrF 2 -fueled radioisotope heat sources. A secondary objective of the program has been to design and qualification-test a general purpose 90 SrF 2 -fueled heat source. The effort expended in the design and testing of the heat source is described. Detailed information is included on: heat source design, licensing requirements, and qualification test requirements; the qualification test procedures; and the fabrication and testing of capsules of various materials. The results obtained in the qualification tests show that the outer capsule design proposed for the 90 SrF 2 heat source is capable of meeting current licensing requirements when Hastelloy S is used as the outer capsule material. The data also indicate that an outer capsule of Hastelloy C-4 would probably also meet licensing requirements, although Hastelloy S is the preferred material. Therefore, based on the results of this study, the general purpose 90 SrF 2 heat source will consist of a standard WESF Hastelloy C-276 inner capsule filled with 90 SrF 2 and a Hastelloy S outer capsule having a 2.375-in. inner diameter and 0.500-in. wall thickness. The end closures for this study, the general purpose 90 SrF 2 heat a Hastelloy S outer capsule having a 2.375-in. inner diameter and 0.500-in. wall thickness. The end closures for the outer capsule will utilize an interlocking joint design requiring a 0.1-in. penetration closure weld

  11. Strontium-90 and cesium-137 in freshwater fish (from Jul. 1984 to Dec. 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in freshwater fish were determined using radiochemical analysis. Three species of fish (Cyprinus carpio, Carassius auratus, and Hypomesus transpacificus nipponensis) were collected during the fishing season from eight sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonized, the sample was ashed in an electric muffle furnace. The maximum value of Sr-90 was 96 +- 1.7 pCi/kg in Cyprinus carpio collected from Akita in July 1984; and that of Cs-137 was 11 +- 0.7 pCi/kg in Carassius auratus from Fukui in December 1984. (Namekawa, K.)

  12. Strontium-90 and cesium-137 in fresh-water fish; April, 1977 to March, 1978

    International Nuclear Information System (INIS)

    1979-01-01

    Each sample is washed in water and wiped with filter paper. Only the estable portion is used in case of a large-sized fish, and the whole is used in case of a small fish. Each is weighed, placed on a stainless pan or porcelain dish, carbonized and further ashed in an electric oven. The results obtained from April 1977 to March 1978 were shown in a table. (J.P.N.)

  13. Strontium-90 and cesium-137 in freshwater fish (from Jul. 1981 to Dec. 1981)

    International Nuclear Information System (INIS)

    1981-01-01

    90 Sr and 137 Cs in freshwater fish (Carassius auratus, Cyprinus carpio and Hypomesus transpacificus nipponensis) were determined. Fish was rinsed with water and blotted with a filter paper. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results from July to December 1981 are shown in a table. (Namekawa, K.)

  14. Strontium-90 content of human bones collected from 1962 to 1966

    International Nuclear Information System (INIS)

    Jeanmaire, L.

    1967-01-01

    The aim of this report is essentially to present results of 90 Sr determination made on human bones collected in the Paris region from 1962 to 1966. The results are classified according to the year and the age-group in, two tables and one figure which show the general evolution of the contamination during this period. (author) [fr

  15. Strontium-90 and cesium-137 in marine sediment; April, 1978 to March, 1979

    International Nuclear Information System (INIS)

    1979-01-01

    The samples of rain and dry fallout, air-borne dust, service water and fresh water, soil, sea water, sea sediment, total diet, rice, milk, vegetables, tea, fish, shellfishes and seaweed, and fresh water fishes, their sampling and prior treatment are described. The methods of separating Sr-90 and Cs-137 and their measurement are explained. The estimations of stable Sr, K and Ca are made by atomic absorption spectroscopy, flame spectrophotometry and potassium permanganate titration, respectively. The general plan of radioactivity survey in Japan is shown. As the environmental data, the results of Sr-90 and Cs-137 in sea sediment obtained from April, 1978, to March, 1979, and the locations of sampling are given. In a table, the months and the locations of sampling, depth (m), and the amounts of Sr-90 and Cs-137 (pCi/kg) are shown. The maximum values are 17 pCi/kg of Sr-90 found in Mutsu Bay and 180 pCi/kg of Cs-137 in Ajisu, Yamaguchi Prefecture, in August, 1978. (Kako, I.)

  16. Strontium-90 and cesium-137 in vegetables (consuming districts) (from May 1981 to Nov. 1981)

    International Nuclear Information System (INIS)

    1981-01-01

    90 Sr and 137 Cs in vegetables (consuming districts) were determined. Spinach and Japanese radish were selected as the representatives for leaf vegetables and for non-starch roots, respectively. The results from May to November 1981 are shown in a table. (Namekawa, K.)

  17. Strontium-90 and cesium-137 in milk (consuming districts) (from Jul. 1984 to Sep. 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in milk from consuming districts were determined using radiochemical analysis. Commercial milk was purchased from 23 sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 2.7 +- 0.28 pCi/l in milk from Akita and 5.3 +- 0.31 pCi/l in milk from Fukushima purchased in August 1984, respectively. (Namekawa, K.)

  18. Visual function after strontium-90 plaque irradiation in patients with age-related subfoveal choroidal neovascularization

    Energy Technology Data Exchange (ETDEWEB)

    Jaakkola, A.; Tarkkanen, A.; Immonen, I. [Helsinki Univ. Central Hospital, Dept. of Ophthalmology (Finland); Heikkonen, J. [Helsinki Univ. Central Hospital, Dept. of Oncology (Finland)

    1999-05-01

    Purpose: To report 2-year visual and angiographic results in eyes treated with strontium plaque irradiation for subfoveal choroidal neovascular membranes (CNVM) in age-related macular degeneration. Methods: Twenty eyes with recent subfoveal CNVM were treated with local irradiation. The impact of the treatment on visual function was evaluated by visual acuity, contrast sensitivity and reading speed testing. Results: At 12 months visual acuity had improved or remained the same in 9/20 eyes (45%). At 24 months visual acuity was stable in 5/18 eyes (28%). Eyes with signs of CNVM regression (13/18,72%) lost a mean of 3.3 lines, but eyes with recurrent CNVM lost a mean of 5.1 lines of vision. The mean contrast sensitivity was better in the irradiated eyes than in the fellow eyes with late age-related macular degeneration at 24 months. Six of 17 irradiated eyes (35%) could read at least some words at 24 months. Conclusion: Visual function decreases in patients treated with strontium irradiation, but less in eyes showing regression of the CNVM than in eyes with further growth of the CNVM. (au) 20 refs.

  19. Comparative toxicity of strontium-90 and radium-226 in beagle dogs

    International Nuclear Information System (INIS)

    Raabe, O.G.; Culbertson, M.R.; White, R.G.; Spangler, W.L.; Cain, G.R.; Parks, N.J.; Samuels, S.J.

    1991-01-01

    We are completing a 30-year study of the biological effects of 90 Sr and 226 Ra in the beagle in order to predict the possible long-term hazards to people from chronic exposure to low levels of irradiation. Animals received either radionuclide by several means of administration: (a) continual ingestion of 90 Sr, (b) a single intravenous injection of 90 Sr, or (c) a series of eight intravenous injections of 226 Ra. Although administration of 90 Sr and 226 Ra ended at 540 days of age, the animals continued to receive chronic, low-level radiation doses from these bone-seeking radionuclides throughout life. This project is the largest single cohort study in beagles of internally deposited radionuclides. It is unique in use of the ingestion route for 90 Sr and in exposure that began before birth and continued throughout development to adulthood with uniform labeling of the skeletons with 90 Sr. The last of the dogs died in 1986 at age 18.5 years, but we are continuing to investigate the significance of these long-term exposures given at low dose rates with regard to cancer production, physiologic well-being, and shortening of life through the detailed records that were kept and by study of preserved materials. All the data have been successfully accumulated and entered into a main-frame computer data base management system. Current work is exclusively directed at preparing research papers summarizing the results and the associated biostatistical and survival analyses. 15 refs., 1 fig., 4 tabs

  20. Equilibrium: two-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In Chapter 6, the problem of toroidal force balance is addressed in the simplest, nontrivial two-dimensional geometry, that of an axisymmetric torus. A derivation is presented of the Grad-Shafranov equation, the basic equation describing axisymmetric toroidal equilibrium. The solutions to equations provide a complete description of ideal MHD equilibria: radial pressure balance, toroidal force balance, equilibrium Beta limits, rotational transform, shear, magnetic wall, etc. A wide number of configurations are accurately modeled by the Grad-Shafranov equation. Among them are all types of tokamaks, the spheromak, the reversed field pinch, and toroidal multipoles. An important aspect of the analysis is the use of asymptotic expansions, with an inverse aspect ratio serving as the expansion parameter. In addition, an equation similar to the Grad-Shafranov equation, but for helically symmetric equilibria, is presented. This equation represents the leading-order description low-Beta and high-Beta stellarators, heliacs, and the Elmo bumpy torus. The solutions all correspond to infinitely long straight helices. Bending such a configuration into a torus requires a full three-dimensional calculation and is discussed in Chapter 7

  1. Equilibrium structure of rare earth trihalides

    International Nuclear Information System (INIS)

    Oezgueven, Y.

    2004-01-01

    In this work, we have calculate the equilibrium structure of the yttrium tribromide (YBr 3 ) and its dimer using the interionic force model . In the determination of the model parameters of Y monomer and dimer we use the measured value of the breathing mode of molecular dimer in the pure molecular liquid. We compare our results for the equilibrium structure of molecular dimer namely, the bond lengths and bond angles, with measured values from electron diffraction and with the results of other theoretical calculations. The agreement between calculated and measured spectra frequencies of vibrational modes can be considered as very reasonable

  2. Entropy and equilibrium via games of complexity

    Science.gov (United States)

    Topsøe, Flemming

    2004-09-01

    It is suggested that thermodynamical equilibrium equals game theoretical equilibrium. Aspects of this thesis are discussed. The philosophy is consistent with maximum entropy thinking of Jaynes, but goes one step deeper by deriving the maximum entropy principle from an underlying game theoretical principle. The games introduced are based on measures of complexity. Entropy is viewed as minimal complexity. It is demonstrated that Tsallis entropy ( q-entropy) and Kaniadakis entropy ( κ-entropy) can be obtained in this way, based on suitable complexity measures. A certain unifying effect is obtained by embedding these measures in a two-parameter family of entropy functions.

  3. Equilibrium current-driven tearing mode in the hydrodynamic regime

    International Nuclear Information System (INIS)

    Cozzani, F.; Mahajan, S.

    1984-12-01

    The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed

  4. Equilibrium and pre-equilibrium emissions in proton-induced ...

    Indian Academy of Sciences (India)

    necessary for the domain of fission-reactor technology for the calculation of nuclear transmutation ... tions occur in three stages: INC, pre-equilibrium and equilibrium (or compound. 344. Pramana ... In the evaporation phase of the reaction, the.

  5. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  6. Equilibrium statistical mechanics

    CERN Document Server

    Jackson, E Atlee

    2000-01-01

    Ideal as an elementary introduction to equilibrium statistical mechanics, this volume covers both classical and quantum methodology for open and closed systems. Introductory chapters familiarize readers with probability and microscopic models of systems, while additional chapters describe the general derivation of the fundamental statistical mechanics relationships. The final chapter contains 16 sections, each dealing with a different application, ordered according to complexity, from classical through degenerate quantum statistical mechanics. Key features include an elementary introduction t

  7. Volatility in Equilibrium

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Sizova, Natalia; Tauchen, George

    Stock market volatility clusters in time, carries a risk premium, is fractionally inte- grated, and exhibits asymmetric leverage effects relative to returns. This paper develops a first internally consistent equilibrium based explanation for these longstanding empirical facts. The model is cast i......, and the dynamic cross-correlations of the volatility measures with the returns calculated from actual high-frequency intra-day data on the S&P 500 aggregate market and VIX volatility indexes....

  8. Molecular equilibrium with condensation

    International Nuclear Information System (INIS)

    Sharp, C.M.; Huebner, W.F.

    1990-01-01

    Minimization of the Gibbs energy of formation for species of chemical elements and compounds in their gas and condensed phases determines their relative abundances in a mixture in chemical equilibrium. The procedure is more general and more powerful than previous abundance determinations in multiphase astrophysical mixtures. Some results for astrophysical equations of state are presented, and the effects of condensation on opacity are briefly indicated. 18 refs

  9. Equilibrium calculations and mode analysis

    International Nuclear Information System (INIS)

    Herrnegger, F.

    1987-01-01

    The STEP asymptotic stellarator expansion procedure was used to study the MHD equilibrium and stability properties of stellarator configurations without longitudinal net-current, which also apply to advanced stellarators. The effects of toroidal curvature and magnetic well, and the Shafranov shift were investigated. A classification of unstable modes in toroidal stellarators is given. For WVII-A coil-field configurations having a β value of 1% and a parabolic pressure profile, no free-boundary modes are found. This agrees with the experimental fact that unstable behavior of the plasma column is not observed for this parameter range. So a theoretical β-limit for stability against ideal MHD modes can be estimated by mode analysis for the WVII-A device

  10. Neoclassical equilibrium in gyrokinetic simulations

    International Nuclear Information System (INIS)

    Garbet, X.; Dif-Pradalier, G.; Nguyen, C.; Sarazin, Y.; Grandgirard, V.; Ghendrih, Ph.

    2009-01-01

    This paper presents a set of model collision operators, which reproduce the neoclassical equilibrium and comply with the constraints of a full-f global gyrokinetic code. The assessment of these operators is based on an entropy variational principle, which allows one to perform a fast calculation of the neoclassical diffusivity and poloidal velocity. It is shown that the force balance equation is recovered at lowest order in the expansion parameter, the normalized gyroradius, hence allowing one to calculate correctly the radial electric field. Also, the conventional neoclassical transport and the poloidal velocity are reproduced in the plateau and banana regimes. The advantages and drawbacks of the various model operators are discussed in view of the requirements for neoclassical and turbulent transport.

  11. Equilibrium calculations, ch. 6

    International Nuclear Information System (INIS)

    Deursen, A.P.J. van

    1976-01-01

    A calculation is presented of dimer intensities obtained in supersonic expansions. There are two possible limiting considerations; the dimers observed are already present in the source, in thermodynamic equilibrium, and are accelerated in the expansion. Destruction during acceleration is neglected, as are processes leading to newly formed dimers. On the other hand one can apply a kinetic approach, where formation and destruction processes are followed throughout the expansion. The difficulty of this approach stems from the fact that the density, temperature and rate constants have to be known at all distances from the nozzle. The simple point of view has been adopted and the measured dimer intensities are compared with the equilibrium concentration in the source. The comparison is performed under the assumption that the detection efficiency for dimers is twice the detection efficiency for monomers. The experimental evidence against the simple point of view that the dimers of the onset region are formed in the source already, under equilibrium conditions, is discussed. (Auth.)

  12. Universality in equilibrium and away from it: A personal perspective

    International Nuclear Information System (INIS)

    Munoz, Miguel A.

    2011-01-01

    In this talk/paper I discuss the concept of universality in phase transitions and the question of whether universality classes are more robust in equilibrium than away from it. In both of these situations, the main ingredients determining universality are symmetries, conservation laws, the dimension of the space and of the order-parameter and the presence of long-range interactions or quenched disorder. The existence of detailed-balance and fluctuation-dissipation theorems imposes severe constraints on equilibrium systems, allowing to define universality classes in a very robust way; instead, non-equilibrium allows for more variability. Still, quite robust non-equilibrium universality classes have been identified in the last decades. Here, I discuss some examples in which (i) non-equilibrium phase transitions are simply controlled by equilibrium critical points, i.e. non-equilibrium ingredients turn out to be irrelevant in the renormalization group sense and (ii) non-equilibrium situations in which equilibrium seems to come out of the blue, generating an adequate effective description of intrinsically non-equilibrium problems. Afterwards, I shall describe different genuinely non-equilibrium phase transitions in which introducing small, apparently innocuous changes (namely: presence or absence of an underlying lattice, parity conservation in the overall number of particles, existence of an un-accessible vacuum state, deterministic versus stochastic microscopic rules, presence or absence of a Fermionic constraint), the critical behavior is altered, making the case for lack of robustness. However, it will be argued that in all these examples, there is an underlying good reason (in terms of general principles) for universality to be altered. The final conclusions are that: (i) robust universality classes exist both in equilibrium and non-equilibrium; (ii) symmetry and conservation principles are crucial in both, (iii) non-equilibrium allows for more variability (i

  13. Noncompact Equilibrium Points and Applications

    Directory of Open Access Journals (Sweden)

    Zahra Al-Rumaih

    2012-01-01

    Full Text Available We prove an equilibrium existence result for vector functions defined on noncompact domain and we give some applications in optimization and Nash equilibrium in noncooperative game.

  14. Equilibrium thermodynamics - Callen's postulational approach

    NARCIS (Netherlands)

    Jongschaap, R.J.J.; Öttinger, Hans Christian

    2001-01-01

    In order to provide the background for nonequilibrium thermodynamics, we outline the fundamentals of equilibrium thermodynamics. Equilibrium thermodynamics must not only be obtained as a special case of any acceptable nonequilibrium generalization but, through its shining example, it also elucidates

  15. MHD equilibrium with toroidal rotation

    International Nuclear Information System (INIS)

    Li, J.

    1987-03-01

    The present work attempts to formulate the equilibrium of axisymmetric plasma with purely toroidal flow within ideal MHD theory. In general, the inertial term Rho(v.Del)v caused by plasma flow is so complicated that the equilibrium equation is completely different from the Grad-Shafranov equation. However, in the case of purely toroidal flow the equilibrium equation can be simplified so that it resembles the Grad-Shafranov equation. Generally one arbitrary two-variable functions and two arbitrary single variable functions, instead of only four single-variable functions, are allowed in the new equilibrium equations. Also, the boundary conditions of the rotating (with purely toroidal fluid flow, static - without any fluid flow) equilibrium are the same as those of the static equilibrium. So numerically one can calculate the rotating equilibrium as a static equilibrium. (author)

  16. Development of a Thermal Equilibrium Prediction Algorithm

    International Nuclear Information System (INIS)

    Aviles-Ramos, Cuauhtemoc

    2002-01-01

    A thermal equilibrium prediction algorithm is developed and tested using a heat conduction model and data sets from calorimetric measurements. The physical model used in this study is the exact solution of a system of two partial differential equations that govern the heat conduction in the calorimeter. A multi-parameter estimation technique is developed and implemented to estimate the effective volumetric heat generation and thermal diffusivity in the calorimeter measurement chamber, and the effective thermal diffusivity of the heat flux sensor. These effective properties and the exact solution are used to predict the heat flux sensor voltage readings at thermal equilibrium. Thermal equilibrium predictions are carried out considering only 20% of the total measurement time required for thermal equilibrium. A comparison of the predicted and experimental thermal equilibrium voltages shows that the average percentage error from 330 data sets is only 0.1%. The data sets used in this study come from calorimeters of different sizes that use different kinds of heat flux sensors. Furthermore, different nuclear material matrices were assayed in the process of generating these data sets. This study shows that the integration of this algorithm into the calorimeter data acquisition software will result in an 80% reduction of measurement time. This reduction results in a significant cutback in operational costs for the calorimetric assay of nuclear materials. (authors)

  17. Non-equilibrium thermodynamics

    CERN Document Server

    De Groot, Sybren Ruurds

    1984-01-01

    The study of thermodynamics is especially timely today, as its concepts are being applied to problems in biology, biochemistry, electrochemistry, and engineering. This book treats irreversible processes and phenomena - non-equilibrium thermodynamics.S. R. de Groot and P. Mazur, Professors of Theoretical Physics, present a comprehensive and insightful survey of the foundations of the field, providing the only complete discussion of the fluctuating linear theory of irreversible thermodynamics. The application covers a wide range of topics: the theory of diffusion and heat conduction, fluid dyn

  18. Magnetic analysis of tokamak plasma with approximate MHD equilibrium solution

    International Nuclear Information System (INIS)

    Moriyama, Shin-ichi; Hiraki, Naoji

    1993-01-01

    A magnetic analysis method for determining equilibrium configuration parameters (plasma shape, poloidal beta and internal inductance) on a non-circular tokamak is described. The feature is to utilize an approximate MHD equilibrium solution which explicitly relates the configuration parameters with the magnetic fields picked up by magnetic sensors. So this method is suitable for the real-time analysis performed during a tokamak discharge. A least-squares fitting procedure is added to the analytical algorithm in order to reduce the errors in the magnetic analysis. The validity is investigated through the numerical calculation for a tokamak equilibrium model. (author)

  19. Equilibrium reconstruction in the TCA/Br tokamak

    International Nuclear Information System (INIS)

    Sa, Wanderley Pires de

    1996-01-01

    The accurate and rapid determination of the Magnetohydrodynamic (MHD) equilibrium configuration in tokamaks is a subject for the magnetic confinement of the plasma. With the knowledge of characteristic plasma MHD equilibrium parameters it is possible to control the plasma position during its formation using feed-back techniques. It is also necessary an on-line analysis between successive discharges to program external parameters for the subsequent discharges. In this work it is investigated the MHD equilibrium configuration reconstruction of the TCA/BR tokamak from external magnetic measurements, using a method that is able to fast determine the main parameters of discharge. The thesis has two parts. Firstly it is presented the development of an equilibrium code that solves de Grad-Shafranov equation for the TCA/BR tokamak geometry. Secondly it is presented the MHD equilibrium reconstruction process from external magnetic field and flux measurements using the Function Parametrization FP method. this method. This method is based on the statistical analysis of a database of simulated equilibrium configurations, with the goal of obtaining a simple relationship between the parameters that characterize the equilibrium and the measurements. The results from FP are compared with conventional methods. (author)

  20. Semi-empirical correlation for binary interaction parameters of the Peng–Robinson equation of state with the van der Waals mixing rules for the prediction of high-pressure vapor–liquid equilibrium

    Directory of Open Access Journals (Sweden)

    Seif-Eddeen K. Fateen

    2013-03-01

    Full Text Available Peng–Robinson equation of state is widely used with the classical van der Waals mixing rules to predict vapor liquid equilibria for systems containing hydrocarbons and related compounds. This model requires good values of the binary interaction parameter kij. In this work, we developed a semi-empirical correlation for kij partly based on the Huron–Vidal mixing rules. We obtained values for the adjustable parameters of the developed formula for over 60 binary systems and over 10 categories of components. The predictions of the new equation system were slightly better than the constant-kij model in most cases, except for 10 systems whose predictions were considerably improved with the new correlation.

  1. Semi-empirical correlation for binary interaction parameters of the Peng-Robinson equation of state with the van der Waals mixing rules for the prediction of high-pressure vapor-liquid equilibrium.

    Science.gov (United States)

    Fateen, Seif-Eddeen K; Khalil, Menna M; Elnabawy, Ahmed O

    2013-03-01

    Peng-Robinson equation of state is widely used with the classical van der Waals mixing rules to predict vapor liquid equilibria for systems containing hydrocarbons and related compounds. This model requires good values of the binary interaction parameter kij . In this work, we developed a semi-empirical correlation for kij partly based on the Huron-Vidal mixing rules. We obtained values for the adjustable parameters of the developed formula for over 60 binary systems and over 10 categories of components. The predictions of the new equation system were slightly better than the constant-kij model in most cases, except for 10 systems whose predictions were considerably improved with the new correlation.

  2. Applicability of Donnan equilibrium theory at nanochannel-reservoir interfaces.

    Science.gov (United States)

    Tian, Huanhuan; Zhang, Li; Wang, Moran

    2015-08-15

    Understanding ionic transport in nanochannels has attracted broad attention from various areas in energy and environmental fields. In most pervious research, Donnan equilibrium has been applied widely to nanofluidic systems to obtain ionic concentration and electrical potential at channel-reservoir interfaces; however, as well known that Donnan equilibrium is derived from classical thermodynamic theories with equilibrium assumptions. Therefore the applicability of the Donnan equilibrium may be questionable when the transport at nanochannel-reservoir interface is strongly non-equilibrium. In this work, the Poisson-Nernst-Planck model for ion transport is numerically solved to obtain the exact distributions of ionic concentration and electrical potential. The numerical results are quantitatively compared with the Donnan equilibrium predictions. The applicability of Donnan equilibrium is therefore justified by changing channel length, reservoir ionic concentration, surface charge density and channel height. The results indicate that the Donnan equilibrium is not applicable for short nanochannels, large concentration difference and wide openings. A non-dimensional parameter, Q factor, is proposed to measure the non-equilibrium extent and the relation between Q and the working conditions is studied in detail. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Equilibrium models and variational inequalities

    CERN Document Server

    Konnov, Igor

    2007-01-01

    The concept of equilibrium plays a central role in various applied sciences, such as physics (especially, mechanics), economics, engineering, transportation, sociology, chemistry, biology and other fields. If one can formulate the equilibrium problem in the form of a mathematical model, solutions of the corresponding problem can be used for forecasting the future behavior of very complex systems and, also, for correcting the the current state of the system under control. This book presents a unifying look on different equilibrium concepts in economics, including several models from related sciences.- Presents a unifying look on different equilibrium concepts and also the present state of investigations in this field- Describes static and dynamic input-output models, Walras, Cassel-Wald, spatial price, auction market, oligopolistic equilibrium models, transportation and migration equilibrium models- Covers the basics of theory and solution methods both for the complementarity and variational inequality probl...

  4. Grinding kinetics and equilibrium states

    Science.gov (United States)

    Opoczky, L.; Farnady, F.

    1984-01-01

    The temporary and permanent equilibrium occurring during the initial stage of cement grinding does not indicate the end of comminution, but rather an increased energy consumption during grinding. The constant dynamic equilibrium occurs after a long grinding period indicating the end of comminution for a given particle size. Grinding equilibrium curves can be constructed to show the stages of comminution and agglomeration for certain particle sizes.

  5. Mental Equilibrium and Rational Emotions

    OpenAIRE

    Eyal Winter; Ignacio Garcia-Jurado; Jose Mendez-Naya; Luciano Mendez-Naya

    2009-01-01

    We introduce emotions into an equilibrium notion. In a mental equilibrium each player "selects" an emotional state which determines the player's preferences over the outcomes of the game. These preferences typically differ from the players' material preferences. The emotional states interact to play a Nash equilibrium and in addition each player's emotional state must be a best response (with respect to material preferences) to the emotional states of the others. We discuss the concept behind...

  6. Para-equilibrium phase diagrams

    International Nuclear Information System (INIS)

    Pelton, Arthur D.; Koukkari, Pertti; Pajarre, Risto; Eriksson, Gunnar

    2014-01-01

    Highlights: • A rapidly cooled system may attain a state of para-equilibrium. • In this state rapidly diffusing elements reach equilibrium but others are immobile. • Application of the Phase Rule to para-equilibrium phase diagrams is discussed. • A general algorithm to calculate para-equilibrium phase diagrams is described. - Abstract: If an initially homogeneous system at high temperature is rapidly cooled, a temporary para-equilibrium state may result in which rapidly diffusing elements have reached equilibrium but more slowly diffusing elements have remained essentially immobile. The best known example occurs when homogeneous austenite is quenched. A para-equilibrium phase assemblage may be calculated thermodynamically by Gibbs free energy minimization under the constraint that the ratios of the slowly diffusing elements are the same in all phases. Several examples of calculated para-equilibrium phase diagram sections are presented and the application of the Phase Rule is discussed. Although the rules governing the geometry of these diagrams may appear at first to be somewhat different from those for full equilibrium phase diagrams, it is shown that in fact they obey exactly the same rules with the following provision. Since the molar ratios of non-diffusing elements are the same in all phases at para-equilibrium, these ratios act, as far as the geometry of the diagram is concerned, like “potential” variables (such as T, pressure or chemical potentials) rather than like “normal” composition variables which need not be the same in all phases. A general algorithm to calculate para-equilibrium phase diagrams is presented. In the limit, if a para-equilibrium calculation is performed under the constraint that no elements diffuse, then the resultant phase diagram shows the single phase with the minimum Gibbs free energy at any point on the diagram; such calculations are of interest in physical vapor deposition when deposition is so rapid that phase

  7. Equilibrium thermodynamics in modified gravitational theories

    International Nuclear Information System (INIS)

    Bamba, Kazuharu; Geng, C.-Q.; Tsujikawa, Shinji

    2010-01-01

    We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density f(R,φ,X), where R is the Ricci scalar and X is the kinetic energy of a scalar field φ. This comes from a suitable definition of an energy-momentum tensor of the 'dark' component that respects to a local energy conservation in the Jordan frame. In this framework the horizon entropy S corresponding to equilibrium thermodynamics is equal to a quarter of the horizon area A in units of gravitational constant G, as in Einstein gravity. For a flat cosmological background with a decreasing Hubble parameter, S globally increases with time, as it happens for viable f(R) inflation and dark energy models. We also show that the equilibrium description in terms of the horizon entropy S is convenient because it takes into account the contribution of both the horizon entropy S in non-equilibrium thermodynamics and an entropy production term.

  8. Mapping Isobaric Aging onto the Equilibrium Phase Diagram.

    Science.gov (United States)

    Niss, Kristine

    2017-09-15

    The linear volume relaxation and the nonlinear volume aging of a glass-forming liquid are measured, directly compared, and used to extract the out-of-equilibrium relaxation time. This opens a window to investigate how the relaxation time depends on temperature, structure, and volume in parts of phase space that are not accessed by the equilibrium liquid. It is found that the temperature dependence of relaxation time is non-Arrhenius even in the isostructural case-challenging the Adam-Gibbs entropy model. Based on the presented data and the idea that aging happens through quasiequilibrium states, we suggest a mapping of the out-of-equilibrium states during isobaric aging to the equilibrium phase diagram. This mapping implies the existence of isostructural lines in the equilibrium phase diagram. The relaxation time is found to depend on the bath temperature, density, and a just single structural parameter, referred to as an effective temperature.

  9. Real time equilibrium reconstruction for tokamak discharge control

    International Nuclear Information System (INIS)

    Ferron, J.R.; Walker, M.L.; Lao, L.L.; St John, H.E.; Humphreys, D.A.; Leuer, J.A.

    1998-01-01

    A practical method for performing a tokamak equilibrium reconstruction in real time for arbitrary time varying discharge shapes and current profiles is described. An approximate solution to the Grad-Shafranov equilibrium relation is found which best fits the diagnostic measurements. Thus, a solution for the spatial distribution of poloidal flux and toroidal current density is available in real time that is consistent with plasma force balance, allowing accurate evaluation of parameters such as discharge shape and safety factor profile. The equilibrium solutions are produced at a rate sufficient for discharge control. This equilibrium reconstruction algorithm has been implemented on the digital plasma control system for the DIII-D tokamak. The first application of real time equilibrium reconstruction to discharge shape control is described. (author)

  10. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  11. Thermodynamic chemical energy transfer mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium chemical reactions

    International Nuclear Information System (INIS)

    Roh, Heui-Seol

    2015-01-01

    Chemical energy transfer mechanisms at finite temperature are explored by a chemical energy transfer theory which is capable of investigating various chemical mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium. Gibbs energy fluxes are obtained as a function of chemical potential, time, and displacement. Diffusion, convection, internal convection, and internal equilibrium chemical energy fluxes are demonstrated. The theory reveals that there are chemical energy flux gaps and broken discrete symmetries at the activation chemical potential, time, and displacement. The statistical, thermodynamic theory is the unification of diffusion and internal convection chemical reactions which reduces to the non-equilibrium generalization beyond the quasi-equilibrium theories of migration and diffusion processes. The relationship between kinetic theories of chemical and electrochemical reactions is also explored. The theory is applied to explore non-equilibrium chemical reactions as an illustration. Three variable separation constants indicate particle number constants and play key roles in describing the distinct chemical reaction mechanisms. The kinetics of chemical energy transfer accounts for the four control mechanisms of chemical reactions such as activation, concentration, transition, and film chemical reactions. - Highlights: • Chemical energy transfer theory is proposed for non-, quasi-, and equilibrium. • Gibbs energy fluxes are expressed by chemical potential, time, and displacement. • Relationship between chemical and electrochemical reactions is discussed. • Theory is applied to explore nonequilibrium energy transfer in chemical reactions. • Kinetics of non-equilibrium chemical reactions shows the four control mechanisms

  12. Fundamental functions in equilibrium thermodynamics

    NARCIS (Netherlands)

    Horst, H.J. ter

    In the standard presentations of the principles of Gibbsian equilibrium thermodynamics one can find several gaps in the logic. For a subject that is as widely used as equilibrium thermodynamics, it is of interest to clear up such questions of mathematical rigor. In this paper it is shown that using

  13. Validation of equilibrium tools on the COMPASS tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Urban, J., E-mail: urban@ipp.cas.cz [Institute of Plasma Physics ASCR, Za Slovankou 3, 182 00 Praha 8 (Czech Republic); Appel, L.C. [CCFE, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); Artaud, J.F. [CEA, IRFM, F-13108 Saint Paul Lez Durance (France); Faugeras, B. [Laboratoire J.A. Dieudonné, UMR 7351, Université de Nice Sophia-Antipolis, Parc Valrose, 06108 Nice Cedex 02 (France); Havlicek, J. [Institute of Plasma Physics ASCR, Za Slovankou 3, 182 00 Praha 8 (Czech Republic); Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Praha 8 (Czech Republic); Komm, M. [Institute of Plasma Physics ASCR, Za Slovankou 3, 182 00 Praha 8 (Czech Republic); Lupelli, I. [CCFE, Culham Science Centre, Abingdon, Oxfordshire (United Kingdom); Peterka, M. [Institute of Plasma Physics ASCR, Za Slovankou 3, 182 00 Praha 8 (Czech Republic); Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, 180 00 Praha 8 (Czech Republic)

    2015-10-15

    Highlights: • Three equilibrium codes—EFIT++, FREEBIE and VacTH—have been successfully set up and validated on COMPASS. • FREEBIE can predictively calculate the equilibrium and corresponding poloidal field coil currents. • EFIT++ can reconstruct equilibria generated by FREEBIE from synthetic, optionally noisy diagnostic data. • VacTH is a promising tool for real time plasma shape reconstruction. • Optimized parameters are estimated for EFIT++ and VacTH by a statistical analysis. - Abstract: Various MHD (magnetohydrodynamic) equilibrium tools, some of which being recently developed or considerably updated, are used on the COMPASS tokamak at IPP Prague. MHD equilibrium is a fundamental property of the tokamak plasma, whose knowledge is required for many diagnostics and modelling tools. Proper benchmarking and validation of equilibrium tools is thus key for interpreting and planning tokamak experiments. We present here benchmarks and comparisons to experimental data of the EFIT++ reconstruction code (Appel et al., 2006), the free-boundary equilibrium code FREEBIE (Artaud and Kim, 2012), and a rapid plasma boundary reconstruction code VacTH (Faugeras et al., 2014). We demonstrate that FREEBIE can calculate the equilibrium and corresponding poloidal field (PF) coils currents consistently with EFIT++ reconstructions from experimental data. Both EFIT++ and VacTH can reconstruct equilibria generated by FREEBIE from synthetic, optionally noisy diagnostic data. Hence, VacTH is suitable for real-time control. Optimum reconstruction parameters are estimated.

  14. Exploring Chemical and Thermal Non-equilibrium in Nitrogen Arcs

    International Nuclear Information System (INIS)

    Ghorui, S; Das, A K

    2012-01-01

    Plasma torches operating with nitrogen are of special importance as they can operate with usual tungsten based refractory electrodes and offer radical rich non-oxidizing high temperature environment for plasma chemistry. Strong gradients in temperature as well as species densities and huge convective fluxes lead to varying degrees of chemical non-equilibrium in associated regions. An axi-symmetric two-temperature chemical non-equilibrium model of a nitrogen plasma torch has been developed to understand the effects of thermal and chemical non-equilibrium in arcs. A 2-D finite volume CFD code in association with a non-equilibrium property routine enabled extraction of steady state self-consistent distributions of various plasma quantities inside the torch under various thermal and chemical non-equilibrium conditions. Chemical non-equilibrium has been incorporated through computation of diffusive and convective fluxes in each finite volume cell in every iteration and associating corresponding thermodynamic and transport properties through the scheme of 'chemical non-equilibrium parameter' introduced by Ghorui et. al. Recombination coefficient data from Nahar et. al. and radiation data from Krey and Morris have been used in the simulation. Results are presented for distributions of temperature, pressure, velocity, current density, electric potential, species densities and chemical non-equilibrium effects. Obtained results are compared with similar results under LTE.

  15. Thermochemical equilibrium modelling of a gasifying process

    International Nuclear Information System (INIS)

    Melgar, Andres; Perez, Juan F.; Laget, Hannes; Horillo, Alfonso

    2007-01-01

    This article discusses a mathematical model for the thermochemical processes in a downdraft biomass gasifier. The model combines the chemical equilibrium and the thermodynamic equilibrium of the global reaction, predicting the final composition of the producer gas as well as its reaction temperature. Once the composition of the producer gas is obtained, a range of parameters can be derived, such as the cold gas efficiency of the gasifier, the amount of dissociated water in the process and the heating value and engine fuel quality of the gas. The model has been validated experimentally. This work includes a parametric study of the influence of the gasifying relative fuel/air ratio and the moisture content of the biomass on the characteristics of the process and the producer gas composition. The model helps to predict the behaviour of different biomass types and is a useful tool for optimizing the design and operation of downdraft biomass gasifiers

  16. Non-equilibrium supramolecular polymerization.

    Science.gov (United States)

    Sorrenti, Alessandro; Leira-Iglesias, Jorge; Markvoort, Albert J; de Greef, Tom F A; Hermans, Thomas M

    2017-09-18

    Supramolecular polymerization has been traditionally focused on the thermodynamic equilibrium state, where one-dimensional assemblies reside at the global minimum of the Gibbs free energy. The pathway and rate to reach the equilibrium state are irrelevant, and the resulting assemblies remain unchanged over time. In the past decade, the focus has shifted to kinetically trapped (non-dissipative non-equilibrium) structures that heavily depend on the method of preparation (i.e., pathway complexity), and where the assembly rates are of key importance. Kinetic models have greatly improved our understanding of competing pathways, and shown how to steer supramolecular polymerization in the desired direction (i.e., pathway selection). The most recent innovation in the field relies on energy or mass input that is dissipated to keep the system away from the thermodynamic equilibrium (or from other non-dissipative states). This tutorial review aims to provide the reader with a set of tools to identify different types of self-assembled states that have been explored so far. In particular, we aim to clarify the often unclear use of the term "non-equilibrium self-assembly" by subdividing systems into dissipative, and non-dissipative non-equilibrium states. Examples are given for each of the states, with a focus on non-dissipative non-equilibrium states found in one-dimensional supramolecular polymerization.

  17. Spontaneity and Equilibrium: Why "?G Equilibrium" Are Incorrect

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The fundamental criteria for chemical reactions to be spontaneous in a given direction are generally incorrectly stated as ?G equilibrium are also misstated as being ?G = 0 or ?A = 0. Following a brief review of the…

  18. Helical axis stellarator equilibrium model

    International Nuclear Information System (INIS)

    Koniges, A.E.; Johnson, J.L.

    1985-02-01

    An asymptotic model is developed to study MHD equilibria in toroidal systems with a helical magnetic axis. Using a characteristic coordinate system based on the vacuum field lines, the equilibrium problem is reduced to a two-dimensional generalized partial differential equation of the Grad-Shafranov type. A stellarator-expansion free-boundary equilibrium code is modified to solve the helical-axis equations. The expansion model is used to predict the equilibrium properties of Asperators NP-3 and NP-4. Numerically determined flux surfaces, magnetic well, transform, and shear are presented. The equilibria show a toroidal Shafranov shift

  19. Numerical Verification Of Equilibrium Chemistry

    International Nuclear Information System (INIS)

    Piro, Markus; Lewis, Brent; Thompson, William T.; Simunovic, Srdjan; Besmann, Theodore M.

    2010-01-01

    A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing boundary conditions in heat and mass transport modules. However, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes.

  20. Equilibrium ignition for ICF capsules

    International Nuclear Information System (INIS)

    Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

    1993-01-01

    There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative

  1. On the local equilibrium condition

    International Nuclear Information System (INIS)

    Hessling, H.

    1994-11-01

    A physical system is in local equilibrium if it cannot be distinguished from a global equilibrium by ''infinitesimally localized measurements''. This should be a natural characterization of local equilibrium, but the problem is to give a precise meaning to the qualitative phrase ''infinitesimally localized measurements''. A solution is suggested in form of a Local Equilibrium Condition (LEC), which can be applied to linear relativistic quantum field theories but not directly to selfinteracting quantum fields. The concept of local temperature resulting from LEC is compared to an old approach to local temperature based on the principle of maximal entropy. It is shown that the principle of maximal entropy does not always lead to physical states if it is applied to relativistic quantum field theories. (orig.)

  2. Local approximation of a metapopulation's equilibrium.

    Science.gov (United States)

    Barbour, A D; McVinish, R; Pollett, P K

    2018-04-18

    We consider the approximation of the equilibrium of a metapopulation model, in which a finite number of patches are randomly distributed over a bounded subset [Formula: see text] of Euclidean space. The approximation is good when a large number of patches contribute to the colonization pressure on any given unoccupied patch, and when the quality of the patches varies little over the length scale determined by the colonization radius. If this is the case, the equilibrium probability of a patch at z being occupied is shown to be close to [Formula: see text], the equilibrium occupation probability in Levins's model, at any point [Formula: see text] not too close to the boundary, if the local colonization pressure and extinction rates appropriate to z are assumed. The approximation is justified by giving explicit upper and lower bounds for the occupation probabilities, expressed in terms of the model parameters. Since the patches are distributed randomly, the occupation probabilities are also random, and we complement our bounds with explicit bounds on the probability that they are satisfied at all patches simultaneously.

  3. Thermodynamic evolution far from equilibrium

    Science.gov (United States)

    Khantuleva, Tatiana A.

    2018-05-01

    The presented model of thermodynamic evolution of an open system far from equilibrium is based on the modern results of nonequilibrium statistical mechanics, the nonlocal theory of nonequilibrium transport developed by the author and the Speed Gradient principle introduced in the theory of adaptive control. Transition to a description of the system internal structure evolution at the mesoscopic level allows a new insight at the stability problem of non-equilibrium processes. The new model is used in a number of specific tasks.

  4. The Optimal Nash Equilibrium Strategies Under Competition

    Institute of Scientific and Technical Information of China (English)

    孟力; 王崇喜; 汪定伟; 张爱玲

    2004-01-01

    This paper presented a game theoretic model to study the competition for a single investment oppertunity under uncertainty. It models the hazard rate of investment as a function of competitors' trigger level. Under uncertainty and different information structure, the option and game theory was applied to researching the optimal Nash equilibrium strategies of one or more firm. By means of Matlab software, the paper simulates a real estate developing project example and illustrates how parameter affects investment strategies. The paper's work will contribute to the present investment practice in China.

  5. Measuring productivity differences in equilibrium search models

    DEFF Research Database (Denmark)

    Lanot, Gauthier; Neumann, George R.

    1996-01-01

    Equilibrium search models require unobserved heterogeneity in productivity to fit observed wage distribution data, but provide no guidance about the location parameter of the heterogeneity. In this paper we show that the location of the productivity heterogeneity implies a mode in a kernel density...... estimate of the wage distribution. The number of such modes and their location are identified using bump hunting techniques due to Silverman (1981). These techniques are applied to Danish panel data on workers and firms. These estimates are used to assess the importance of employer wage policy....

  6. Relevance of equilibrium in multifragmentation

    International Nuclear Information System (INIS)

    Furuta, Takuya; Ono, Akira

    2009-01-01

    The relevance of equilibrium in a multifragmentation reaction of very central 40 Ca + 40 Ca collisions at 35 MeV/nucleon is investigated by using simulations of antisymmetrized molecular dynamics (AMD). Two types of ensembles are compared. One is the reaction ensemble of the states at each reaction time t in collision events simulated by AMD, and the other is the equilibrium ensemble prepared by solving the AMD equation of motion for a many-nucleon system confined in a container for a long time. The comparison of the ensembles is performed for the fragment charge distribution and the excitation energies. Our calculations show that there exists an equilibrium ensemble that well reproduces the reaction ensemble at each reaction time t for the investigated period 80≤t≤300 fm/c. However, there are some other observables that show discrepancies between the reaction and equilibrium ensembles. These may be interpreted as dynamical effects in the reaction. The usual static equilibrium at each instant is not realized since any equilibrium ensemble with the same volume as that of the reaction system cannot reproduce the fragment observables

  7. Shape characteristics of equilibrium and non-equilibrium fractal clusters.

    Science.gov (United States)

    Mansfield, Marc L; Douglas, Jack F

    2013-07-28

    It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other

  8. Comparative evaluation of kinetic, equilibrium and semi-equilibrium models for biomass gasification

    Energy Technology Data Exchange (ETDEWEB)

    Buragohain, Buljit [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Chakma, Sankar; Kumar, Peeush [Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Mahanta, Pinakeswar [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Moholkar, Vijayanand S. [Center for Energy, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India); Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati – 781 039, Assam (India)

    2013-07-01

    Modeling of biomass gasification has been an active area of research for past two decades. In the published literature, three approaches have been adopted for the modeling of this process, viz. thermodynamic equilibrium, semi-equilibrium and kinetic. In this paper, we have attempted to present a comparative assessment of these three types of models for predicting outcome of the gasification process in a circulating fluidized bed gasifier. Two model biomass, viz. rice husk and wood particles, have been chosen for analysis, with gasification medium being air. Although the trends in molar composition, net yield and LHV of the producer gas predicted by three models are in concurrence, significant quantitative difference is seen in the results. Due to rather slow kinetics of char gasification and tar oxidation, carbon conversion achieved in single pass of biomass through the gasifier, calculated using kinetic model, is quite low, which adversely affects the yield and LHV of the producer gas. Although equilibrium and semi-equilibrium models reveal relative insensitivity of producer gas characteristics towards temperature, the kinetic model shows significant effect of temperature on LHV of the gas at low air ratios. Kinetic models also reveal volume of the gasifier to be an insignificant parameter, as the net yield and LHV of the gas resulting from 6 m and 10 m riser is same. On a whole, the analysis presented in this paper indicates that thermodynamic models are useful tools for quantitative assessment of the gasification process, while kinetic models provide physically more realistic picture.

  9. Experimental determination of thermodynamic equilibrium in biocatalytic transamination.

    Science.gov (United States)

    Tufvesson, Pär; Jensen, Jacob S; Kroutil, Wolfgang; Woodley, John M

    2012-08-01

    The equilibrium constant is a critical parameter for making rational design choices in biocatalytic transamination for the synthesis of chiral amines. However, very few reports are available in the scientific literature determining the equilibrium constant (K) for the transamination of ketones. Various methods for determining (or estimating) equilibrium have previously been suggested, both experimental as well as computational (based on group contribution methods). However, none of these were found suitable for determining the equilibrium constant for the transamination of ketones. Therefore, in this communication we suggest a simple experimental methodology which we hope will stimulate more accurate determination of thermodynamic equilibria when reporting the results of transaminase-catalyzed reactions in order to increase understanding of the relationship between substrate and product molecular structure on reaction thermodynamics. Copyright © 2012 Wiley Periodicals, Inc.

  10. Radiation protection - radionuclides - Synthesis sheets: Thorium-232 (ED 4317), Gallium-67 (ED 4314), Indium-111 (ED 4315), Chromium-51 (ED 4313), Thallium-201 (ED 4312), Phosphorus-33 (ED 4316), Fluorine- 18 (ED 4311), Yttrium-90 (ED 4310), Americium-241 (ED 4308), Strontium-90 (ED 4309), Sulfur-35 (ED 4307), Iodine-125 (ED 4306), Phosphorus-32 (ED 4305), Iodine-123 (ED 4304), Tritium (ED 4303), Carbon-14 (ED 4302), Technetium-99m (ED 4301), Iodine-131 (ED 4300)

    International Nuclear Information System (INIS)

    Deligne, Jean-Michel; Sert, Gilles; Rannou, Alain; Vidal, Jean-Pierre; Aubert, Bernard; Despres, Alain; Donadille, Laurent; Biau, Alain; Pihet, Pascal; Vial, Eric; Gambini, Denis-Jean; Gauron, Christine; Servent, Jean-Pierre; Moureaux, Patrick; Girod, Michel; Ammerich, Marc; Herbelet, Gilbert; Lahaye, Thierry; Le Dirac'h, Bertrand; Le Guen, Bernard; Manin, Jean-Pierre; Roussille, Francoise; Frot, Patricia

    2013-12-01

    For each radionuclide, this document presents its characteristics (origin, radio-physical properties, biological properties), gives an overview of its uses, indicates and discusses its dosimetric parameters (for internal or external exposure), indicates radiation detection and contamination measurement techniques, gives an overview of means of protection (for premises, against external or internal exposure), describes the delimitation and control of premises, describes aspects related to personnel classification, training and medical monitoring, comments the issue of effluents and wastes, indicates administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources, addresses the issue of transport, and describes what is to be done in case of incident or accident

  11. Analysis of equilibrium and topology of tokamak plasmas

    International Nuclear Information System (INIS)

    Milligen, B.P. van.

    1991-01-01

    In a tokamak, the plasma is confined by means of a magnetic field. There exists an equilibrium between outward forces due to the pressure gradient in plasma and inward forces due to the interaction between currents flowing inside the plasma and the magnetic field. The equilibrium magnetic field is characterized by helical field lines that lie on nested toroidal surfaces of constant flux. The equilibrium yields values for global and local plasma parameters (e.g. plasma position, total current, local pressure). Thus, precise knowledge of the equilibrium is essential for plasma control, for the understanding of many phenomena occurring in the plasma (in particular departures from the ideal equilibrium involving current filamentation on the flux surfaces that lead to the formation of islands, i.e. nested helical flux surfaces), and for the interpretation of many different types of measurements (e.g. the translation of line integrated electron density measurements made by laser beams probing the plasma into a local electron density on a flux surface). The problem of determining the equilibrium magnetic field from external magnetic field measurements has been studied extensively in literature. The problem is 'ill-posed', which means that the solution is unstable to small changes in the measurement data, and the solution has to be constrained in order to stabilize it. Various techniques for handling this problem have been suggested in literature. Usually ad-hoc restrictions are imposed on the equilibrium solution in order to stabilize it. More equilibrium solvers are not able to handle very dissimilar measurement data which means information on the equilibrium is lost. The generally do not allow a straightforward error estimate of the obtained results to be made, and they require large amounts of computing time. This problems are addressed in this thesis. (author). 104 refs.; 42 figs.; 6 tabs

  12. Equilibrium figures for beta Lyrae type disks

    International Nuclear Information System (INIS)

    Wilson, R.E.

    1981-01-01

    Accumulated evidence for a geometrically and optically thick disk in the β Lyrae system has now established the disk's basic external configuration. Since the disk has been constant in its main properties over the historical interval of β Lyrae observations and also seems to have a basically well-defined photosphere, it is now time to being consideration of its sturcture. Here, we compute equilibrium figures for self-gravitating disks around stars in binary systems as a start toward eventual computation of complete disk models. A key role is played by centrifugally limited rotation of the central star, which would naturally arise late in the rapid phase of mass transfer. Beta Lyrae is thus postulated to be a double-contact binary, which makes possible nonarbitrary separation of star and disk into separate structures. The computed equilibrium figures are three-dimensional, as the gravitation of the second star is included. Under the approximation that the gravitational potential of the disk is that of a thin wire and that the local disk angular velocity is proportional to u/sup n/ (u = distance from rotation axis), we comptue the total potential and locate equipotential surfaces. The centrifugal potential is written in a particularly convenient form which permits one to change the rotation law discontinuously (for example, at the star-disk coupling point) while ensuring that centrifugal potential and centrifigual force are continuous functions of position. With such a one-parameter rotation law, one can find equilibrium disk figures with dimensions very similar to those found in β Lyrae, but considerations of internal consistency demand at least a two-parameter law

  13. Local Equilibrium and Retardation Revisited.

    Science.gov (United States)

    Hansen, Scott K; Vesselinov, Velimir V

    2018-01-01

    In modeling solute transport with mobile-immobile mass transfer (MIMT), it is common to use an advection-dispersion equation (ADE) with a retardation factor, or retarded ADE. This is commonly referred to as making the local equilibrium assumption (LEA). Assuming local equilibrium, Eulerian textbook treatments derive the retarded ADE, ostensibly exactly. However, other authors have presented rigorous mathematical derivations of the dispersive effect of MIMT, applicable even in the case of arbitrarily fast mass transfer. We resolve the apparent contradiction between these seemingly exact derivations by adopting a Lagrangian point of view. We show that local equilibrium constrains the expected time immobile, whereas the retarded ADE actually embeds a stronger, nonphysical, constraint: that all particles spend the same amount of every time increment immobile. Eulerian derivations of the retarded ADE thus silently commit the gambler's fallacy, leading them to ignore dispersion due to mass transfer that is correctly modeled by other approaches. We then present a particle tracking simulation illustrating how poor an approximation the retarded ADE may be, even when mobile and immobile plumes are continually near local equilibrium. We note that classic "LEA" (actually, retarded ADE validity) criteria test for insignificance of MIMT-driven dispersion relative to hydrodynamic dispersion, rather than for local equilibrium. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  14. Equilibrium study for ternary mixtures of biodiesel

    Science.gov (United States)

    Doungsri, S.; Sookkumnerd, T.; Wongkoblap, A.; Nuchitprasittichai, A.

    2017-11-01

    The liquid-liquid equilibrium (LLE) data for the ternary mixtures of methanol + fatty acid methyl ester (FAME) + palm oil and FAME + palm oil + glycerol at various temperatures from 35 to 55°C, the tie lines and binodial curves were also investigated and plotted in the equilibrium curve. The experimental results showed that the binodial curves of methanol + FAME + palm oil depended significantly with temperature while the binodial curves of FAME + palm oil + glycerol illustrated insignificant change with temperatures. The interaction parameters between liquid pair obtained for NRTL (Nonrandom Two-Liquid) and UNIQUAC (Universal Quasi-Chemical Theory) models from the experimental data were also investigated. It was found that the correlated parameters of UNIQUAC model for system of FAME + palm oil + glycerol, denoted as a13 and a31, were 580.42K and -123.69K, respectively, while those for system of methanol + FAME + palm oil, denoted as a42 and a24, were 71.48 K and 965.57K, respectively. The ternary LLE data reported here would be beneficial for engineers and scientists to use for prediction of yield and purity of biodiesel for the production. The UNIQUAC model agreed well with the experimental data of ternary mixtures of biodiesel.

  15. Equilibrium Arrival Times to Queues

    DEFF Research Database (Denmark)

    Breinbjerg, Jesper; Østerdal, Lars Peter

    We consider a non-cooperative queueing environment where a finite number of customers independently choose when to arrive at a queueing system that opens at a given point in time and serves customers on a last-come first-serve preemptive-resume (LCFS-PR) basis. Each customer has a service time...... requirement which is identically and independently distributed according to some general probability distribution, and they want to complete service as early as possible while minimizing the time spent in the queue. In this setting, we establish the existence of an arrival time strategy that constitutes...... a symmetric (mixed) Nash equilibrium, and show that there is at most one symmetric equilibrium. We provide a numerical method to compute this equilibrium and demonstrate by a numerical example that the social effciency can be lower than the effciency induced by a similar queueing system that serves customers...

  16. Spontaneity and Equilibrium: Why "?G Equilibrium" Are Incorrect

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The fundamental criteria for chemical reactions to be spontaneous in a given direction are generally incorrectly stated as ?G chemistry textbooks and even in some more advanced texts. Similarly, the criteria for equilibrium are also misstated as being ?G = 0 or ?A = 0. Following a brief review of the…

  17. Equilibrium in a Production Economy

    Energy Technology Data Exchange (ETDEWEB)

    Chiarolla, Maria B., E-mail: maria.chiarolla@uniroma1.it [Universita di Roma ' La Sapienza' , Dipartimento di Metodi e Modelli per l' Economia, il Territorio e la Finanza, Facolta di Economia (Italy); Haussmann, Ulrich G., E-mail: uhaus@math.ubc.ca [University of British Columbia, Department of Mathematics (Canada)

    2011-06-15

    Consider a closed production-consumption economy with multiple agents and multiple resources. The resources are used to produce the consumption good. The agents derive utility from holding resources as well as consuming the good produced. They aim to maximize their utility while the manager of the production facility aims to maximize profits. With the aid of a representative agent (who has a multivariable utility function) it is shown that an Arrow-Debreu equilibrium exists. In so doing we establish technical results that will be used to solve the stochastic dynamic problem (a case with infinite dimensional commodity space so the General Equilibrium Theory does not apply) elsewhere.

  18. Incentives in Supply Function Equilibrium

    DEFF Research Database (Denmark)

    Vetter, Henrik

    2014-01-01

    The author analyses delegation in homogenous duopoly under the assumption that the firm-managers compete in supply functions. In supply function equilibrium, managers’ decisions are strategic complements. This reverses earlier findings in that the author finds that owners give managers incentives...... to act in an accommodating way. As a result, optimal delegation reduces per-firm output and increases profits to above-Cournot profits. Moreover, in supply function equilibrium the mode of competition is endogenous. This means that the author avoids results that are sensitive with respect to assuming...

  19. Equilibrium in a Production Economy

    International Nuclear Information System (INIS)

    Chiarolla, Maria B.; Haussmann, Ulrich G.

    2011-01-01

    Consider a closed production-consumption economy with multiple agents and multiple resources. The resources are used to produce the consumption good. The agents derive utility from holding resources as well as consuming the good produced. They aim to maximize their utility while the manager of the production facility aims to maximize profits. With the aid of a representative agent (who has a multivariable utility function) it is shown that an Arrow-Debreu equilibrium exists. In so doing we establish technical results that will be used to solve the stochastic dynamic problem (a case with infinite dimensional commodity space so the General Equilibrium Theory does not apply) elsewhere.

  20. The Equilibrium Rule--A Personal Discovery

    Science.gov (United States)

    Hewitt, Paul G.

    2016-01-01

    Examples of equilibrium are evident everywhere and the equilibrium rule provides a reasoned way to view all things, whether in static (balancing rocks, steel beams in building construction) or dynamic (airplanes, bowling balls) equilibrium. Interestingly, the equilibrium rule applies not just to objects at rest but whenever any object or system of…

  1. Non equilibrium atomic processes and plasma spectroscopy

    International Nuclear Information System (INIS)

    Kato, Takako

    2003-01-01

    Along with the technical progress in plasma spectroscopy, non equilibrium ionization processes have been recently observed. We study non local thermodynamic equilibrium and non ionization equilibrium for various kinds of plasmas. Specifically we discuss non equilibrium atomic processes in magnetically confined plasmas, solar flares and laser produced plasmas using a collisional radiative model based on plasma spectroscopic data. (author)

  2. SRB states and nonequilibrium statistical mechanics close to equilibrium

    OpenAIRE

    Gallavotti, Giovannni; Ruelle, David

    1996-01-01

    Nonequilibrium statistical mechanics close to equilibrium is studied using SRB states and a formula for their derivatives with respect to parameters. We write general expressions for the thermodynamic fluxes (or currents) and the transport coefficients, generalizing previous results. In this framework we give a general proof of the Onsager reciprocity relations.

  3. Equilibrium and kinetics studies of metal ion adsorption on dyed ...

    African Journals Online (AJOL)

    GREGO

    2007-04-02

    Apr 2, 2007 ... Initial concentration of Cu(II) ions = 20 mg/l, adsorbent dose = 1.0 g. Table 2 Experiment Data of ... diffusivity of the metal ion would be independent of the extent of sorption .... exchange and adsorption. Equilibrium parameter.

  4. Energy equation for the analysis of magnetization relaxation to equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Bertotti, G. [IEN Galileo Ferraris, Materials Department, Strada delle Cacce, 91, I-10135 Torino (Italy)]. E-mail: bertotti@ien.it; Bonin, R. [Dipartimento di Fisica, Politecnico di Torino, I-10129 Torino (Italy); Magni, A. [IEN Galileo Ferraris, Materials Department, Strada delle Cacce, 91, I-10135 Torino (Italy); Mayergoyz, I.D. [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland, 20742 (United States); Serpico, C. [Dipartimento di Ingegneria Elettrica, Universita di Napoli ' Federico II' , I-80125 Naples (Italy)

    2005-02-01

    Magnetization relaxation starting from a generic non-equilibrium state is analytically described. An equation for the energy decay is obtained. On this basis, an approximate expression for the magnetization motion during the ringing process is obtained in terms of Jacobi elliptic functions with time-dependent parameters.

  5. Energy equation for the analysis of magnetization relaxation to equilibrium

    International Nuclear Information System (INIS)

    Bertotti, G.; Bonin, R.; Magni, A.; Mayergoyz, I.D.; Serpico, C.

    2005-01-01

    Magnetization relaxation starting from a generic non-equilibrium state is analytically described. An equation for the energy decay is obtained. On this basis, an approximate expression for the magnetization motion during the ringing process is obtained in terms of Jacobi elliptic functions with time-dependent parameters

  6. Supersymmetric Field Theory of Non-Equilibrium Thermodynamic System

    OpenAIRE

    Olemskoi, Alexander I.; Brazhnyi, Valerii A.

    1998-01-01

    On the basis of Langevin equation the optimal SUSY field scheme is formulated to discribe a non-equilibrium thermodynamic system with quenched disorder and non-ergodicity effects. Thermodynamic and isothermal susceptibilities, memory parameter and irreversible response are determined at different temperatures and quenched disorder intensities.

  7. Equilibrium and kinetics studies of metal ion adsorption on dyed ...

    African Journals Online (AJOL)

    Batch equilibration studies were conducted to determine the nature of adsorption of Zn (II) and Cu (II) onto dyed coconut pollens. The nature of adsorption of metal ions was explained using the Langmuir equation. The calculated values of equilibrium parameter indicated favourable adsorption by the adsorbents. Also the ...

  8. Numerical equilibrium analysis for structured consumer resource models

    NARCIS (Netherlands)

    de Roos, A.M.; Diekmann, O.; Getto, P.; Kirkilionis, M.A.

    2010-01-01

    In this paper, we present methods for a numerical equilibrium and stability analysis for models of a size structured population competing for an unstructured re- source. We concentrate on cases where two model parameters are free, and thus existence boundaries for equilibria and stability boundaries

  9. Numerical equilibrium analysis for structured consumer resource models

    NARCIS (Netherlands)

    de Roos, A.M.; Diekmann, O.; Getto, P.; Kirkilionis, M.A.

    2010-01-01

    In this paper, we present methods for a numerical equilibrium and stability analysis for models of a size structured population competing for an unstructured resource. We concentrate on cases where two model parameters are free, and thus existence boundaries for equilibria and stability boundaries

  10. Estimating Dynamic Equilibrium Models using Macro and Financial Data

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Posch, Olaf; van der Wel, Michel

    We show that including financial market data at daily frequency, along with macro series at standard lower frequency, facilitates statistical inference on structural parameters in dynamic equilibrium models. Our continuous-time formulation conveniently accounts for the difference in observation...... of the estimators and estimate the model using 20 years of U.S. macro and financial data....

  11. Non-equilibrium fluctuation-induced interactions

    International Nuclear Information System (INIS)

    Dean, David S

    2012-01-01

    We discuss non-equilibrium aspects of fluctuation-induced interactions. While the equilibrium behavior of such interactions has been extensively studied and is relatively well understood, the study of these interactions out of equilibrium is relatively new. We discuss recent results on the non-equilibrium behavior of systems whose dynamics is of the dissipative stochastic type and identify a number of outstanding problems concerning non-equilibrium fluctuation-induced interactions.

  12. Understanding Thermal Equilibrium through Activities

    Science.gov (United States)

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-01-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 "Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education" pp 169-72) we…

  13. Equilibrium theory : A salient approach

    NARCIS (Netherlands)

    Schalk, S.

    1999-01-01

    Whereas the neoclassical models in General Equilibrium Theory focus on the existence of separate commodities, this thesis regards 'bundles of trade' as the unit objects of exchange. Apart from commodities and commodity bundles in the neoclassical sense, the term `bundle of trade' includes, for

  14. Essays in general equilibrium theory

    NARCIS (Netherlands)

    Konovalov, A.

    2001-01-01

    The thesis focuses on various issues of general equilibrium theory and can approximately be divided into three parts. The first part of the thesis studies generalized equilibria in the Arrow-Debreu model in the situation where the strong survival assumption is not satisfied. Chapter four deals with

  15. Financial equilibrium with career concerns

    Directory of Open Access Journals (Sweden)

    Amil Dasgupta

    2006-03-01

    Full Text Available What are the equilibrium features of a financial market where a sizeable proportion of traders face reputational concerns? This question is central to our understanding of financial markets, which are increasingly dominated by institutional investors. We construct a model of delegated portfolio management that captures key features of the US mutual fund industry and embed it in an asset pricing framework. We thus provide a formal model of financial equilibrium with career concerned agents. Fund managers differ in their ability to understand market fundamentals, and in every period investors choose a fund. In equilibrium, the presence of career concerns induces uninformed fund managers to churn, i.e., to engage in trading even when they face a negative expected return. Churners act as noise traders and enhance the level of trading volume. The equilibrium relationship between fund return and net fund flows displays a skewed shape that is consistent with stylized facts. The robustness of our core results is probed from several angles.

  16. Equilibrium with arbitrary market structure

    DEFF Research Database (Denmark)

    Grodal, Birgit; Vind, Karl

    2005-01-01

    . The complete market predicted by this theory is clearly unrealistic, and Radner [10] formulated and proved existence of equilibrium in a multiperiod model with incomplete markets. In this paper the Radner result is extended. Radner assumed a specific structure of markets, independence of preferences...

  17. Nash equilibrium with lower probabilities

    DEFF Research Database (Denmark)

    Groes, Ebbe; Jacobsen, Hans Jørgen; Sloth, Birgitte

    1998-01-01

    We generalize the concept of Nash equilibrium in mixed strategies for strategic form games to allow for ambiguity in the players' expectations. In contrast to other contributions, we model ambiguity by means of so-called lower probability measures or belief functions, which makes it possible...

  18. Analytic, two fluid, field reversed configuration equilibrium with sheared rotation

    International Nuclear Information System (INIS)

    Sobehart, J.R.

    1989-01-01

    A two fluid model is used to derive an analytical equilibrium for elongated field reversed configurations containing shear in both the electron and ion velocity profiles. Like some semiempirical models used previously, the analytical expressions obtained provide a satisfactory fit to the experimental results for all radii with a few key parameters. The present results reduce to the rigid rotor model and the infinite conductivity case for a specific choice of the parameters

  19. Influence of arc current and pressure on non-chemical equilibrium air arc behavior

    Science.gov (United States)

    Yi, WU; Yufei, CUI; Jiawei, DUAN; Hao, SUN; Chunlin, WANG; Chunping, NIU

    2018-01-01

    The influence of arc current and pressure on the non-chemical equilibrium (non-CE) air arc behavior of a nozzle structure was investigated based on the self-consistent non-chemical equilibrium model. The arc behavior during both the arc burning and arc decay phases were discussed at different currents and different pressures. We also devised the concept of a non-equilibrium parameter for a better understanding of non-CE effects. During the arc burning phase, the increasing current leads to a decrease of the non-equilibrium parameter of the particles in the arc core, while the increasing pressure leads to an increase of the non-equilibrium parameter of the particles in the arc core. During the arc decay phase, the non-CE effect will decrease by increasing the arc burning current and the nozzle pressure. Three factors together—convection, diffusion and chemical reactions—influence non-CE behavior.

  20. On generalized operator quasi-equilibrium problems

    Science.gov (United States)

    Kum, Sangho; Kim, Won Kyu

    2008-09-01

    In this paper, we will introduce the generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which generalize the operator equilibrium problem due to Kazmi and Raouf [K.R. Kazmi, A. Raouf, A class of operator equilibrium problems, J. Math. Anal. Appl. 308 (2005) 554-564] into multi-valued and quasi-equilibrium problems. Using a Fan-Browder type fixed point theorem in [S. Park, Foundations of the KKM theory via coincidences of composites of upper semicontinuous maps, J. Korean Math. Soc. 31 (1994) 493-519] and an existence theorem of equilibrium for 1-person game in [X.-P. Ding, W.K. Kim, K.-K. Tan, Equilibria of non-compact generalized games with L*-majorized preferences, J. Math. Anal. Appl. 164 (1992) 508-517] as basic tools, we prove new existence theorems on generalized operator equilibrium problem and generalized operator quasi-equilibrium problem which includes operator equilibrium problems.

  1. Non-Equilibrium Properties from Equilibrium Free Energy Calculations

    Science.gov (United States)

    Pohorille, Andrew; Wilson, Michael A.

    2012-01-01

    Calculating free energy in computer simulations is of central importance in statistical mechanics of condensed media and its applications to chemistry and biology not only because it is the most comprehensive and informative quantity that characterizes the eqUilibrium state, but also because it often provides an efficient route to access dynamic and kinetic properties of a system. Most of applications of equilibrium free energy calculations to non-equilibrium processes rely on a description in which a molecule or an ion diffuses in the potential of mean force. In general case this description is a simplification, but it might be satisfactorily accurate in many instances of practical interest. This hypothesis has been tested in the example of the electrodiffusion equation . Conductance of model ion channels has been calculated directly through counting the number of ion crossing events observed during long molecular dynamics simulations and has been compared with the conductance obtained from solving the generalized Nernst-Plank equation. It has been shown that under relatively modest conditions the agreement between these two approaches is excellent, thus demonstrating the assumptions underlying the diffusion equation are fulfilled. Under these conditions the electrodiffusion equation provides an efficient approach to calculating the full voltage-current dependence routinely measured in electrophysiological experiments.

  2. Forces and energy dissipation in inhomogeneous non-equilibrium superconductors

    International Nuclear Information System (INIS)

    Poluehktov, Yu.M.; Slezov, V.V.

    1987-01-01

    The phenomenological theory of volume forces and dissipation processes in inhomogeneous non-equilibrium superconductors near temperature transition from the normal to superconducting state is constructed. The approach is based on application of dynamic equations of superconductivity formulated on the basis of the Lagrangian formalism. These equations are generalized the Ginzburg-Landau theory in the nonstationary non-equilibrium case for ''foul'' superconductors. The value estimations of volume forces arising in inhomogeneities during relaxation of an order parameter and when the electrical field is penetrated into the superconductor, are given

  3. Fixed Points in Grassmannians with Applications to Economic Equilibrium

    DEFF Research Database (Denmark)

    Keiding, Hans

    2017-01-01

    In some applications of equilibrium theory, the fixed point involves not only a state and a value of a parameter in the dual of the state space, but also a particular subspace of the state space. Since the set of all subspaces of a finite-dimensional Euclidean space has a structure which does...... not allow immediate application of fixed point theorems, the problem must be reformulated using a suitable parametrization of subspaces. One such parametrization, the Plücker coordinates, is used here to prove a general equilibrium existence theorem. Applications to economic problems involving hierarchies...... of consumers or incomplete markets with real assets are outlined....

  4. Experimental approaches for studying non-equilibrium atmospheric plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Shashurin, A., E-mail: ashashur@purdue.edu [School of Aeronautics & Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Keidar, M. [Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, District of Columbia 20052 (United States)

    2015-12-15

    This work reviews recent research efforts undertaken in the area non-equilibrium atmospheric plasma jets with special focus on experimental approaches. Physics of small non-equilibrium atmospheric plasma jets operating in kHz frequency range at powers around few Watts will be analyzed, including mechanism of breakdown, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species, discharge current spreading, transient dynamics of various plasma parameters, etc. Experimental diagnostic approaches utilized in the field will be considered, including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, fast photographing, etc.

  5. Simplified method for the determination of strontium-90 in large amounts of bone-ash; Methode simplifiee de dosage du strontium 90 sur des quantites importantes de cendres d'os

    Energy Technology Data Exchange (ETDEWEB)

    Patti, F; Jeanmaire, L [Commissariat a l' Energie Atomique, Fontenay-aux-roses (France). Centre d' Etudes Nucleaires

    1966-06-01

    The principle of the determination is based on a 3-step process: 1) concentrating the strontium by attacking the ash with nitric acid; 2) elimination of residual phosphoric ions by a double precipitation of strontium oxalate; and 3) extraction of yttrium 90, counted in the oxalate form. The advantages of the method: -) using simple techniques it makes it possible to process 50 g of ash; -) the initial concentration of strontium considerably reduces the volume of the solutions as well as the size of precipitates handled. Fuming nitric acid is used in a specially designed burette. (authors) [French] Le principe du dosage repos sur un procede en 3 etapes: 1) Concentration du strontium par une attaque nitrique des cendres; 2) Elimination des ions phosphoriques restants par une double precipitation de l'oxalate de strontium. 3) Extraction de l'yttrium 90, compte sous forme d'oxalate. Interet de la methode: dans des conditions techniques simples, elle permet le traitement de 50 g de cendres d'os; la concentration initiale du strontium reduit notablement le volume des solutions ainsi que l'importance des precipites manipules. L'acide nitrique fumant est utilise par l'intermediaire d'une burette specialement concue a cet effet.

  6. Equilibrium studies of helical axis stellarators

    International Nuclear Information System (INIS)

    Hender, T.C.; Carreras, B.A.; Garcia, L.; Harris, J.H.; Rome, J.A.; Cantrell, J.L.; Lynch, V.E.

    1984-01-01

    The equilibrium properties of helical axis stellarators are studied with a 3-D equilibrium code and with an average method (2-D). The helical axis ATF is shown to have a toroidally dominated equilibrium shift and good equilibria up to at least 10% peak beta. Low aspect ratio heliacs, with relatively large toroidal shifts, are shown to have low equilibrium beta limits (approx. 5%). Increasing the aspect ratio and number of field periods proportionally is found to improve the equilibrium beta limit. Alternatively, increasing the number of field periods at fixed aspect ratio which raises and lowers the toroidal shift improves the equilibrium beta limit

  7. Students’ misconceptions on solubility equilibrium

    Science.gov (United States)

    Setiowati, H.; Utomo, S. B.; Ashadi

    2018-05-01

    This study investigated the students’ misconceptions of the solubility equilibrium. The participants of the study consisted of 164 students who were in the science class of second year high school. Instrument used is two-tier diagnostic test consisting of 15 items. Responses were marked and coded into four categories: understanding, misconception, understand little without misconception, and not understanding. Semi-structured interviews were carried out with 45 students according to their written responses which reflected different perspectives, to obtain a more elaborated source of data. Data collected from multiple methods were analyzed qualitatively and quantitatively. Based on the data analysis showed that the students misconceptions in all areas in solubility equilibrium. They had more misconceptions such as in the relation of solubility and solubility product, common-ion effect and pH in solubility, and precipitation concept.

  8. Establishment of database for Japan Sea parameters on marine environment and radioactivity (JASPER). Volume 2. Radiocarbon and oceanographic properties

    International Nuclear Information System (INIS)

    Otosaka, Shigeyoshi; Suzuki, Takashi; Ito, Toshimichi; Kobayashi, Takuya; Kawamura, Hideyuki; Togawa, Orihiko; Tanaka, Takayuki; Minakawa, Masayuki; Aramaki, Takafumi; Senjyu, Tomoharu

    2010-02-01

    The database for the Japan Sea Parameters on Marine Environment and Radionuclides (JASPER) has been established by the Japan Atomic Energy Agency as a product of the Japan Sea Expeditions. By the previous volume of the database, data for representative anthropogenic radionuclides (strontium-90, cesium-137, and plutonium-239, 240) were opened to public. And now, data for radiocarbon and fundamental oceanographic properties (salinity, temperature, dissolved oxygen) including nutrients (silicate, phosphate, nitrate and nitrite) are released as the second volume of the database. At the beginning of this report (chapter 1), backgrounds, objectives and brief overview of this report are given as an introduction. Then, specifications of this database and methodology in obtaining the concentration data are described in chapter 2. The data stored in the database are presented in tabular and figure forms in chapter 3. Finally, chapter 4 is assigned concluding remarks. In the second version of database, 20,292 data records are stored in the database including 2,695 data for temperature, 2,883 data for salinity, 2,109 data for dissolved oxygen, 11,051 data for the nutrients, and 1,660 data for radiocarbon. The database will be a strong tool for the continuous monitoring for contamination by anthropogenic radionuclides, studies on biogeochemical cycle, and development/validation of models for numerical simulations in the sea. (author)

  9. Using nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) for simultaneous determination of concentration and equilibrium constant.

    Science.gov (United States)

    Kanoatov, Mirzo; Galievsky, Victor A; Krylova, Svetlana M; Cherney, Leonid T; Jankowski, Hanna K; Krylov, Sergey N

    2015-03-03

    Nonequilibrium capillary electrophoresis of equilibrium mixtures (NECEEM) is a versatile tool for studying affinity binding. Here we describe a NECEEM-based approach for simultaneous determination of both the equilibrium constant, K(d), and the unknown concentration of a binder that we call a target, T. In essence, NECEEM is used to measure the unbound equilibrium fraction, R, for the binder with a known concentration that we call a ligand, L. The first set of experiments is performed at varying concentrations of T, prepared by serial dilution of the stock solution, but at a constant concentration of L, which is as low as its reliable quantitation allows. The value of R is plotted as a function of the dilution coefficient, and dilution corresponding to R = 0.5 is determined. This dilution of T is used in the second set of experiments in which the concentration of T is fixed but the concentration of L is varied. The experimental dependence of R on the concentration of L is fitted with a function describing their theoretical dependence. Both K(d) and the concentration of T are used as fitting parameters, and their sought values are determined as the ones that generate the best fit. We have fully validated this approach in silico by using computer-simulated NECEEM electropherograms and then applied it to experimental determination of the unknown concentration of MutS protein and K(d) of its interactions with a DNA aptamer. The general approach described here is applicable not only to NECEEM but also to any other method that can determine a fraction of unbound molecules at equilibrium.

  10. An introduction to equilibrium thermodynamics

    CERN Document Server

    Morrill, Bernard; Hartnett, James P; Hughes, William F

    1973-01-01

    An Introduction to Equilibrium Thermodynamics discusses classical thermodynamics and irreversible thermodynamics. It introduces the laws of thermodynamics and the connection between statistical concepts and observable macroscopic properties of a thermodynamic system. Chapter 1 discusses the first law of thermodynamics while Chapters 2 through 4 deal with statistical concepts. The succeeding chapters describe the link between entropy and the reversible heat process concept of entropy; the second law of thermodynamics; Legendre transformations and Jacobian algebra. Finally, Chapter 10 provides a

  11. Measured MHD equilibrium in Alcator C

    International Nuclear Information System (INIS)

    Pribyl, P.A.

    1986-03-01

    A method of processing data from a set of partial Rogowski loops is developed to study the MHD equilibrium in Alcator C. Time dependent poloidal fields in the vicinity of the plasma are calculated from measured currents, with field penetration effects being accounted for. Fields from eddy currents induced by the plasma in the tokamak structure are estimated as well. Each of the set of twelve B/sub θ/ measurements can then be separated into a component from the plasma current and a component from currents external to the pickup loops. Harmonic solutions to Maxwell's equations in toroidal coordinates are fit to these measurements in order to infer the fields everywhere in the vacuum region surrounding the plasma. Using this diagnostic, plasma current, position, shape, and the Shafranov term Λ = β/sub p/ + l/sub i//2 - 1 may be computed, and systematic studies of these plasma parameters are undertaken for Alcator C plasmas

  12. Rejecting the equilibrium-point hypothesis.

    Science.gov (United States)

    Gottlieb, G L

    1998-01-01

    The lambda version of the equilibrium-point (EP) hypothesis as developed by Feldman and colleagues has been widely used and cited with insufficient critical understanding. This article offers a small antidote to that lack. First, the hypothesis implicitly, unrealistically assumes identical transformations of lambda into muscle tension for antagonist muscles. Without that assumption, its definitions of command variables R, C, and lambda are incompatible and an EP is not defined exclusively by R nor is it unaffected by C. Second, the model assumes unrealistic and unphysiological parameters for the damping properties of the muscles and reflexes. Finally, the theory lacks rules for two of its three command variables. A theory of movement should offer insight into why we make movements the way we do and why we activate muscles in particular patterns. The EP hypothesis offers no unique ideas that are helpful in addressing either of these questions.

  13. Local equilibrium in bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  14. Equilibrium optimization code OPEQ and results of applying it to HT-7U

    International Nuclear Information System (INIS)

    Zha Xuejun; Zhu Sizheng; Yu Qingquan

    2003-01-01

    The plasma equilibrium configuration has a strong impact on the confinement and MHD stability in tokamaks. For designing a tokamak device, it is an important issue to determine the sites and currents of poloidal coils which have some constraint conditions from physics and engineering with a prescribed equilibrium shape of the plasma. In this paper, an effective method based on multi-variables equilibrium optimization is given. The method can optimize poloidal coils when the previously prescribed plasma parameters are treated as an object function. We apply it to HT-7U equilibrium calculation, and obtain good results

  15. An equilibrium-conserving taxation scheme for income from capital

    Science.gov (United States)

    Tempere, Jacques

    2018-02-01

    Under conditions of market equilibrium, the distribution of capital income follows a Pareto power law, with an exponent that characterizes the given equilibrium. Here, a simple taxation scheme is proposed such that the post-tax capital income distribution remains an equilibrium distribution, albeit with a different exponent. This taxation scheme is shown to be progressive, and its parameters can be simply derived from (i) the total amount of tax that will be levied, (ii) the threshold selected above which capital income will be taxed and (iii) the total amount of capital income. The latter can be obtained either by using Piketty's estimates of the capital/labor income ratio or by fitting the initial Pareto exponent. Both ways moreover provide a check on the amount of declared income from capital.

  16. Dynamical Symmetries and Causality in Non-Equilibrium Phase Transitions

    Directory of Open Access Journals (Sweden)

    Malte Henkel

    2015-11-01

    Full Text Available Dynamical symmetries are of considerable importance in elucidating the complex behaviour of strongly interacting systems with many degrees of freedom. Paradigmatic examples are cooperative phenomena as they arise in phase transitions, where conformal invariance has led to enormous progress in equilibrium phase transitions, especially in two dimensions. Non-equilibrium phase transitions can arise in much larger portions of the parameter space than equilibrium phase transitions. The state of the art of recent attempts to generalise conformal invariance to a new generic symmetry, taking into account the different scaling behaviour of space and time, will be reviewed. Particular attention will be given to the causality properties as they follow for co-variant n-point functions. These are important for the physical identification of n-point functions as responses or correlators.

  17. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    Directory of Open Access Journals (Sweden)

    G. L. Dotto

    2013-03-01

    Full Text Available The equilibrium and thermodynamics of azo dye (tartrazine and allura red biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium experimental data (R²>0.99 and ARE<5.0% and the maximum biosorption capacities were 363.2 and 468.7 mg g-1 for tartrazine and allura red, respectively, obtained at 298 K. The negative values of ΔG and ΔH showed that the biosorption of both dyes was spontaneous, favorable and exothermic. The positive values of ΔS suggested that the system disorder increases during the biosorption process.

  18. Quantum dynamical semigroups and approach to equilibrium

    International Nuclear Information System (INIS)

    Frigerio, A.

    1977-01-01

    For a quantum dynamical semigroup possessing a faithful normal stationary state, some conditions are discussed, which ensure the uniqueness of the equilibrium state and/or the approach to equilibrium for arbitrary initial condition. (Auth.)

  19. Radiological effect of caesium-137 and strontium-90 on aquatic system of the pathway of the discharged liquid radioactive waste

    International Nuclear Information System (INIS)

    Sinakhom, F.; Pothipin, K.; Supaokit, P.

    1984-12-01

    The objective of this paper is to study the radiological effect from the release of treated liquid radioactive waste to the fresh water environment in order to the protection of human health. The emphasis in this program was concentrated on Sr-90 and Cs-137 analyses on Sr-90 and Cs-137 analyses in surface water, water-plants and fish collected during August 1980 to July 1981. Sr-90 concentration was separated by solvent extraction (TBP-tributyl phosphate) procedure. Beta radioactivity of the two nuclides were measured in the form of yttrium oxalate (Y-90, the daughter nuclide of Sr-90) and caesium phospho-molybdate using a low-background anticoincidence proportional counter. To interpret the result obtained, the analytical data were converted to percent derived working limits (%DWL) using Derived Working Limit acquired from the value of (MPC) and water consumption rate stipulated by ICRP as 100% DWL. The value of %DWL is a useful and convenient index to judge the hazardous from radiation exposed by a certain group of people. The interpretation of the result revealed the equivalence of %DWL of Sr-90 and Cs-137 in canal-fish and swamp cabbage for people resided nearby the canal who obtained their whole protein from consumption of that fish from canal and vegetation grown in that water. The value above was equal 2.5 percent which means that this critical group of people exposed to the radiation only 2.5 percent of that intake limit recommended by ICRP. Thus, the amounts of waste disposed of from waste treatment plant into the canal were too small to have a radiological effect on the environment

  20. Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

    Science.gov (United States)

    Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

    2016-04-01

    The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution.

  1. Strontium-90 and cesium-137 in rice (producing and consuming districts) (from Sep. 1983 to Dec. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Sr-90 and Cs-137 in rice were determined using radiochemical analysis. Polished rice was collected in six producing districts at the harvest and in 18 consuming areas when new crops were first put on sale. The sample was carbonized and ashed in a porcelain dish. The maximum values of Sr-90 and Cs-137 were 1.00 +- 0.16 pCi/Kg in rice collected from a consuming district of Akita and 7.2 +- 0.28 pCi/Kg from a producing district of Ibaragi in November 1983, respectively. (Namekawa, K.)

  2. Increase in accumulation of strontium-90 in the maternal skeleton during pregnancy and lactation: analysis of the Techa River data

    Energy Technology Data Exchange (ETDEWEB)

    Tolstykh, Evgenia I.; Shagina, Natalia B.; Degteva, Marina O. [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation)

    2014-08-15

    The unique contamination of the Techa River (Southern Urals, Russia) in the 1950s by long-lived {sup 90}Sr allows investigation of the accumulation of bone-seeking elements in humans. This study is based on information compiled at the Urals Research Center for Radiation Medicine (Chelyabinsk, Russia) over a long period of time. It includes the results of in vivo measurements of {sup 90}Sr-body burden with a whole body counter (WBC), data on personal medical examinations and residence and family histories. Data on 185 women from two Techa riverside villages Muslyumovo and Brodokalmak were selected. The settlements differ in terms of {sup 90}Sr diet intake (higher in Muslyumovo than in Brodokalmak) and ethnicity (residents were mainly Slavs in Brodokalmak and Turkic in Muslyumovo). Results of a total of 555 WBC measurements performed in 1974-1997 were available for the women studied; maximum measured values reached 40 kBq/body. The women from each settlement were subdivided into three groups according to their childbearing history: pregnancy and lactation occurred (1) during the period of maximal {sup 90}Sr intake (1950-1951); (2) after the period of maximal intake and (3) before this period or women who were childless. An increase was found in accumulation of {sup 90}Sr in maternal skeleton during pregnancy and lactation (group 1) by a factor of 1.5-2 in comparison with non-pregnant, non-lactating women. This result was found in both Muslyumovo and Brodokalmak samples. An increase in accumulation of toxic elements in pregnant/lactating women is associated with increased radiation/toxic doses and risk for the women's health. (orig.)

  3. Strontium-90 and cesium-137 in milk (producing districts for domestic program) (from Jun. 1984 to Oct. 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in milk from producing districts for domestic program were determined using radiochemical analysis. Raw milk was collected from six sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 2.3 +- 0.26 pCi/l in milk from Ishikawa and 2.5 +- 0.22 pCi/l in milk from Ehime, respectively, collected in August 1984. (Namekawa, K.)

  4. Strontium-90 determination in air dust filter using solid phase extraction after the accident of FD-NPS

    International Nuclear Information System (INIS)

    Zhang, Zijian; Kakitani, Shunsuke; Ninomiya, Kazuhiko

    2013-01-01

    Radioactivities of Sr-90 in air-dust filters collected in Hitachi, Kawasaki and Toyonaka were determined using solid state extraction method and low background beta-ray counting system. In Hitachi, though the Sr-90 activity concentration was decreased with time, the activity rates of Sr-90/Cs-137 kept about 10"-"3 order. This fact suggests that Sr-90 transportation behavior in the atmosphere is similar to that of Cs-137 during the time of sample collection. (author)

  5. Strontium-90 and cesium-137 in milk (producing districts for WHO program) from Nov. 1983 to Jan. 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in milk from producing districts for WHO program were determined using radiochemical analysis. Raw milk was collected from 11 sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 11.0+-0.50 pCi/l and 50.0+-0.90 pCi/l, respectively, in milk from Tokyo in February 1984. (Namekawa, K.)

  6. Strontium-90 and cesium-137 in milk (producing districts for domestic program) from Jun. 1983 to Sept. 1983

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in milk from producing districts for domestic program were determined using radiochemical analysis. Raw milk was collected from six sampling locations. Milk in a stainless steel pan or a porcelain dish was evaporated to dryness followed by carbonization and ashing. The maximum values of Sr-90 and Cs-137 were 2.8+-0.30 pCi/l and 1.8+-0.23 pCi/l, respectively, in milk collected from Aomori in February 1984. (Namekawa, K.)

  7. Method of grass samples preparation for strontium-90 and cesium-137 analysis with the exception of ashing

    International Nuclear Information System (INIS)

    Antonova, V.A.; Prokof'ev, O.N.; Khazina, M.A.; Bajkovskaya, L.V.

    1978-01-01

    A method is proposed for the preparation of grass samples in the analysis for 90 Sr and 137 Cs, in which radionuclides are removed into solution as a result of the thermal treatment of samples in 0.01N solution of hydrochloric acid. A grass sample 0.8 kg in weight is covered with 8-10 l of 0.01 N solution of hydrochloric acid and boiled for 30 min, while being constantly stirred. The solution is filtered through cheese cloth, carriers for 90 Y and 137 Cs are introduced, and then oxalates are precipitated at pH=4. After the oxalates have been separated from the filtrate the 137 Cs content is determined using the antimonium-iodide technique. The oxalate precipitate is calcined, dissolved in 2N hydrochloric acid, while boiling, and precipitated by ammonia. The precipitate of hydrooxides is filtered. The solution is acidified by 2N hydrochloric acid up to pH 2-3, and the carrier for 90 Y is introduced. The 90 Sr content is determined by a conventional technique. The percentage of the transition of radionuclides from the grass samples into solution ammounts to: 88+-6% for 90 Sr, and 81+-7% for 137 Cs

  8. AN INNOVATIVE APPROACH FOR CONSTRUCTING AN IN-SITU BARRIER FOR STRONTIUM-90 AT THE HANFORD SITE WASHINGTON

    Energy Technology Data Exchange (ETDEWEB)

    FABRE RJ

    2008-12-08

    Efforts to reduce the flux of Sr-90 to the Columbia River from Hanford Site 100-N Area past-practice liquid waste disposal sites have been underway since the early 1990s. Termination of all liquid discharges to the ground in 1993 was a major step toward meeting this goal. However, Sr-90 adsorbed on aquifer solids beneath liquid waste disposal sites and extending beneath the near-shore riverbed remains a continuing contaminant source to groundwater and the Columbia River. The initial pump-and-treat system proved to be ineffective as a long-term solution because of the geochemical characteristics of Sr-90. Following an evaluation of potential Sr-90 treatment technologies and their applicability under 100-NR-2 Operable Unit hydrogeologic conditions, the U.S. Department of Energy and the Washington State Department of Ecology agreed to evaluate apatite sequestration as the primary remedial technology, combined with a secondary polishing step utilizing phytoextraction if necessary. Aqueous injection was initiated in July 2005 to assess the efficacy of in-situ apatite along the 100 m of shoreline where Sr-90 concentrations are highest. The remedial technology is being developed by Pacific Northwest National Laboratory. CH2M Hill Plateau Remediation Company is implementing this technology in the field with support from PNNL.

  9. An Innovative Approach for Constructing an In-Situ Barrier for Strontium-90 at the Hanford Site, Washington - 9325

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, K. M.; Fabre, Russel J.; Vermeul, Vincent R.; Szecsody, James E.; Fellows, Robert J.; Williams, Mark D.; Fruchter, Jonathan S.

    2008-12-10

    Efforts to reduce the flux of Sr-90 to the Columbia River from Hanford Site 100-N Area past-practice liquid waste disposal sites have been underway since the early 1990s. Termination of all liquid discharges to the ground in 1993 was a major step toward meeting this goal. However, Sr 90 adsorbed on aquifer solids beneath liquid waste disposal sites and extending beneath the near-shore riverbed remains a continuing contaminant source to groundwater and the Columbia River. The initial pump-and treat system proved to be ineffective as a long-term solution because of the geochemical characteristics of Sr-90. Following an evaluation of potential Sr-90 treatment technologies and their applicability under 100 NR-2 Operable Unit hydrogeologic conditions, the U.S. Department of Energy and the Washington State Department of Ecology agreed to evaluate apatite sequestration as the primary remedial technology, combined with a secondary polishing step utilizing phytoextraction if necessary. Aqueous injection was initiated in July 2005 to assess the efficacy of in-situ apatite along the 100 m of shoreline where Sr-90 concentrations are highest. The remedial technology is being developed by Pacific Northwest National Laboratory. CH2M Hill Plateau Remediation Company is implementing this technology in the field with support from PNNL.

  10. Towards a method of rapid extraction of strontium-90 from urine: urine pretreatment and alkali metal removal

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Dietz, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Kaminski, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Shkrob, I. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-03-01

    A technical program to support the Centers of Disease Control and Prevention is being developed to provide an analytical method for rapid extraction of Sr-90 from urine, with the intent of assessing the general population’s exposure during an emergency response to a radiological terrorist event. Results are presented on the progress in urine sample preparation and chemical separation steps that provide an accurate and quantitative detection of Sr-90 based upon an automated column separation sequence and a liquid scintillation assay. Batch extractions were used to evaluate the urine pretreatment and the column separation efficiency and loading capacity based upon commercial, extractant-loaded resins. An efficient pretreatment process for decolorizing and removing organics from urine without measurable loss of radiostrontium from the sample was demonstrated. In addition, the Diphonix® resin shows promise for the removal of high concentrations of common strontium interferents in urine as a first separation step for Sr-90 analysis.

  11. Strontium-90 in alfalfa (Medicago sativa) around the Hanford site in southeastern Washington state: an evaluation of surveillance data

    International Nuclear Information System (INIS)

    Poston, T.M.; Jaquish, R.E.; Antonio, E.J.; Patton, G.W.

    1998-01-01

    From 1988–1994, 90 Sr concentrations in alfalfa (Medicago sativa) grown in areas receiving irrigation water from the Columbia River downstream of Hanford have exceeded concentrations observed in alfalfa grown nearby using other irrigation water sources. Surveillance data indicate that the relationship is not linked to atmospheric releases from Hanford. Attributing the apparent differences in 90 Sr concentrations to irrigation water is equivocal. Evaluations of 90 Sr in Columbia River water fail to consistently show a statistically significant (P > 0.05) contribution at locations immediately downstream of Hanford. Modeling of past 90 Sr fallout accumulation in soil indicates that the potential contribution from Hanford liquid effluents entering the Columbia River, subsequently used as irrigation water from 1972 to 1992, would account for ~ 2% of 90 Sr in soil. The remaining 98% arises from historic atomic weapons testing fallout. Radiological doses modeled for an alfalfa-cow's milk-human pathway indicate that the maximum 50 year effective dose equivalent to a standard man who consumes 270 l of milk per year was 0.9 μSv, which is < 0.03% of the 3 mSv annual dose resulting from natural sources of radiation exposure

  12. Response of pig skin to single doses of irradiation from strontium-90 sources of differing surface area

    Energy Technology Data Exchange (ETDEWEB)

    Hopewell, J.W.; Hamlet, R.; Peel, D. (Churchill Hospital, Oxford (UK). Research Inst.)

    1985-08-01

    In the present investigations the effects of irradiation of pig skin with 22.5 and 40 mm diameter /sup 90/Sr plaques are compared. In addition to comparing peak epithelial reactions, comparisons were also made as to the healing times for comparable peak skin reactions for each field size. The ED/sub 50/ values (dose to produce moist desquamation in 50% of the skin fields) 26.5 +- 1.5 Gy for the 22.5 diameter field was not significantly different from that obtained for the larger 40 mm diameter source (ED/sub 50/ 29.0 +- 1.5 Gy).

  13. Strontium-90 induced squamous cell carcinoma of the gingiva: beta flux measurements from the mandible and teeth surfaces

    International Nuclear Information System (INIS)

    Parks, N.J.; Swartz, L.; Spangler, W.L.; Book, S.A.; Chrisp, C.E.; Hines, H.H. Jr.

    1980-01-01

    Twenty-two of 387 dogs exposed to 90 Sr in utero and by continuous ingestion to 540 days developed squamous cell carcinoma of the gingiva. Eleven of the 22 tumors were observed in dogs ingesting 12 μCi/day. No gingival tumors were observed in dogs ingesting less than 1.25 μCi/day, but 3 were observed at this level. The teeth of these animals acquire a 90 Sr burden which is not removed by skeletal remodeling. Thermoluminescent dosimetry was used to determine the beta radiation flux from teeth and bone into adjacent gingival tissue

  14. Direct measurement of strontium-90 and uranium-238 in soils on a real-time basis: 1994 summary report

    International Nuclear Information System (INIS)

    Schilk, A.J.; Hubbard, C.W.; Knopf, M.A.; Thompson, R.C.

    1995-04-01

    Traditional methodologies for quantitative characterization of radionuclide-contaminated soils over extended areas are often tedious, costly, and non-representative. A rapid characterization methodology was designed that provides reliable output with spatial resolution on the order of a few meters or less. It incorporates an innovative sensor of square plastic scintillating fibers that has been designed to be placed directly on or above a contaminated soil to detect and quantify high-energy beta particles associated with the decay chains of uranium and/or strontium. Under the direction and auspices of the DOE's Characterization, Monitoring, and Sensor Technology Integrated Program, Pacific Northwest Laboratory (PNL) constructed a high-energy beta scintillation sensor that was optimized for the detection and quantification of uranium and strontium contamination in surface soils (in the presence of potentially interfering natural and anthropogenic radionuclides), demonstrated and evaluated this detector in various field and laboratory scenarios, and provides this document in completion of the aforementioned requirements

  15. The uptake and transfer of caesium-137, strontium-90 and zinc-65 from soil to food crops in tropical environment

    International Nuclear Information System (INIS)

    Sachdev, P.; Sachdev, M.S.; Deb, D.L.

    1998-01-01

    The soil to plant transfer factors (TF) of 137 Cs, 90 Sr and 65 Zn were determined for two crops, pearlmillet (Pennisetum typhoides) and sorghum (Sorghum vulgare) under irrigated conditions in greenhouse and in natural conditions of rain in field. The accumulation of 137 Cs was almost doubled when the soil contamination level was doubled. Under the field conditions, 137 Cs concentration in both pearlmillet and sorghum grains as well as straw was nearly four times more at a higher level of soil contamination (148 kBq/kg soil) compared to that at a lower level of 74 kBq/kg soil. 90 Sr absorption by both the crops was nearly 50 to 100 times more compared to 137 Cs under identical conditions of crop growth and soil contamination. 65 Zn concentration was higher in pearlmillet grains than in straw portions, whereas in sorghum it was otherwise. The TF values for 137 Cs decreased nearly ten fold in the second year both under field and pot culture conditions, while those for 90 Sr reduced by half and for 65 Zn by about five times. Under irrigated conditions in field the transfer factors for 137 Cs were nearly four times larger both for pearlmillet and sorghum (1996 experiment) and for 90 Sr more than two times, compared to those under rain fed conditions obtained in 1994. (author)

  16. Environmental levels of strontium 90 and cesium 137 from the fall-out in the Argentine Republic

    International Nuclear Information System (INIS)

    Ciallella, Hugo E.; Fernandez, Jorge A.; Lewis, Esther C.; Quintana, Eduardo E.

    2004-01-01

    Since 1960 collection and measurement of environmental samples from Buenos Aires city and surroundings was periodically carried out. The contamination levels from radioactive fall out was determinated. This paper use a test procedure to analyse statistically the variation of the environmental levels of Sr 90 and Cs 137 in deposition, milk and aerosol samples. The analysed data have two different groups, one of them corresponding to the atmospheric nuclear weapons tests period and the other without explosions in the southern hemisphere. Moreover, integrated concentration of both radionuclides is presented and the received dose was compared with the natural radiation dose. (author)

  17. Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 2. Usage of coal fly ash

    International Nuclear Information System (INIS)

    Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E.

    1996-01-01

    It has been shown that coal fly ash is a good adsorbent for both radionuclides of 137 Cs and 90 Sr. Radiocesium adsorption is maximal around the neutral region whereas radiostrontium adsorption increases with pH, especially above pH 8. Cesium retention sharply drops with ionic strength while strontium adsorption increases sharply and steadily at low and moderate concentrations of the inert electrolyte, respectively. The suggested mechanisms of radionuclide retention by fly ash is specific adsorption of Cs + and irreversible ion-exchange uptake of Sr 2+ . The isotherm of adsorption is a Langmuir approximation of the B.E.T. multi-layered sorption. Acid pretreatment of fly ash, though not increasing radionuclide sorption capacity, may be useful in preventing the leach-out of other contaminants from the sorbent into water during the adsorption process. (author)

  18. Sorptive removal of cesium-137 and strontium-90 from water by unconventional sorbents. 2. Usage of coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Apak, R.; Atun, G.; Gueclue, K.; Tuetem, E. [Istanbul Univ. (Turkey). Faculty of Engineering

    1996-05-01

    It has been shown that coal fly ash is a good adsorbent for both radionuclides of {sup 137}Cs and {sup 90}Sr. Radiocesium adsorption is maximal around the neutral region whereas radiostrontium adsorption increases with pH, especially above pH 8. Cesium retention sharply drops with ionic strength while strontium adsorption increases sharply and steadily at low and moderate concentrations of the inert electrolyte, respectively. The suggested mechanisms of radionuclide retention by fly ash is specific adsorption of Cs{sup +} and irreversible ion-exchange uptake of Sr{sup 2+}. The isotherm of adsorption is a Langmuir approximation of the B.E.T. multi-layered sorption. Acid pretreatment of fly ash, though not increasing radionuclide sorption capacity, may be useful in preventing the leach-out of other contaminants from the sorbent into water during the adsorption process. (author).

  19. The response of pig skin to single doses of irradiation from strontium-90 sources of differing surface area

    International Nuclear Information System (INIS)

    Hopewell, J.W.; Hamlet, R.; Peel, D.

    1985-01-01

    In the present investigations the effects of irradiation of pig skin with 22.5 and 40 mm diameter 90 Sr plaques are compared. In addition to comparing peak epithelial reactions, comparisons were also made as to the healing times for comparable peak skin reactions for each field size. The ED 50 values (dose to produce moist desquamation in 50% of the skin fields) 26.5+-1.5 Gy for the 22.5 diameter field was not significantly different from that obtained for the larger 40 mm diameter source (ED 50 29.0+-1.5 Gy). (U.K.)

  20. 10 CFR 32.61 - Ice detection devices containing strontium-90; requirements for license to manufacture or...

    Science.gov (United States)

    2010-01-01

    ...; requirements for license to manufacture or initially transfer. 32.61 Section 32.61 Energy NUCLEAR REGULATORY COMMISSION SPECIFIC DOMESTIC LICENSES TO MANUFACTURE OR TRANSFER CERTAIN ITEMS CONTAINING BYPRODUCT MATERIAL... manufacture or initially transfer. An application for a specific license to manufacture or initially transfer...

  1. The geometry of finite equilibrium sets

    DEFF Research Database (Denmark)

    Balasko, Yves; Tvede, Mich

    2009-01-01

    We investigate the geometry of finite datasets defined by equilibrium prices, income distributions, and total resources. We show that the equilibrium condition imposes no restrictions if total resources are collinear, a property that is robust to small perturbations. We also show that the set...... of equilibrium datasets is pathconnected when the equilibrium condition does impose restrictions on datasets, as for example when total resources are widely noncollinear....

  2. Accelerating Multiagent Reinforcement Learning by Equilibrium Transfer.

    Science.gov (United States)

    Hu, Yujing; Gao, Yang; An, Bo

    2015-07-01

    An important approach in multiagent reinforcement learning (MARL) is equilibrium-based MARL, which adopts equilibrium solution concepts in game theory and requires agents to play equilibrium strategies at each state. However, most existing equilibrium-based MARL algorithms cannot scale due to a large number of computationally expensive equilibrium computations (e.g., computing Nash equilibria is PPAD-hard) during learning. For the first time, this paper finds that during the learning process of equilibrium-based MARL, the one-shot games corresponding to each state's successive visits often have the same or similar equilibria (for some states more than 90% of games corresponding to successive visits have similar equilibria). Inspired by this observation, this paper proposes to use equilibrium transfer to accelerate equilibrium-based MARL. The key idea of equilibrium transfer is to reuse previously computed equilibria when each agent has a small incentive to deviate. By introducing transfer loss and transfer condition, a novel framework called equilibrium transfer-based MARL is proposed. We prove that although equilibrium transfer brings transfer loss, equilibrium-based MARL algorithms can still converge to an equilibrium policy under certain assumptions. Experimental results in widely used benchmarks (e.g., grid world game, soccer game, and wall game) show that the proposed framework: 1) not only significantly accelerates equilibrium-based MARL (up to 96.7% reduction in learning time), but also achieves higher average rewards than algorithms without equilibrium transfer and 2) scales significantly better than algorithms without equilibrium transfer when the state/action space grows and the number of agents increases.

  3. The Geometry of Finite Equilibrium Datasets

    DEFF Research Database (Denmark)

    Balasko, Yves; Tvede, Mich

    We investigate the geometry of finite datasets defined by equilibrium prices, income distributions, and total resources. We show that the equilibrium condition imposes no restrictions if total resources are collinear, a property that is robust to small perturbations. We also show that the set...... of equilibrium datasets is pathconnected when the equilibrium condition does impose restrictions on datasets, as for example when total resources are widely non collinear....

  4. Optimal Dispatching of Active Distribution Networks Based on Load Equilibrium

    Directory of Open Access Journals (Sweden)

    Xiao Han

    2017-12-01

    Full Text Available This paper focuses on the optimal intraday scheduling of a distribution system that includes renewable energy (RE generation, energy storage systems (ESSs, and thermostatically controlled loads (TCLs. This system also provides time-of-use pricing to customers. Unlike previous studies, this study attempts to examine how to optimize the allocation of electric energy and to improve the equilibrium of the load curve. Accordingly, we propose a concept of load equilibrium entropy to quantify the overall equilibrium of the load curve and reflect the allocation optimization of electric energy. Based on this entropy, we built a novel multi-objective optimal dispatching model to minimize the operational cost and maximize the load curve equilibrium. To aggregate TCLs into the optimization objective, we introduced the concept of a virtual power plant (VPP and proposed a calculation method for VPP operating characteristics based on the equivalent thermal parameter model and the state-queue control method. The Particle Swarm Optimization algorithm was employed to solve the optimization problems. The simulation results illustrated that the proposed dispatching model can achieve cost reductions of system operations, peak load curtailment, and efficiency improvements, and also verified that the load equilibrium entropy can be used as a novel index of load characteristics.

  5. Thermal equilibrium control by frequent bang-bang modulation.

    Science.gov (United States)

    Yang, Cheng-Xi; Wang, Xiang-Bin

    2010-05-01

    In this paper, we investigate the non-Markovian heat transfer between a weakly damped harmonic oscillator (system) and a thermal bath. When the system is initially in a thermal state and not correlated with the environment, the mean energy of the system always first increases, then oscillates, and finally reaches equilibrium with the bath, no matter what the initial temperature of the system is. Moreover, the heat transfer between the system and the bath can be controlled by fast bang-bang modulation. This modulation does work on the system, and temporarily inverts the direction of heat flow. In this case, the common sense that heat always transfers from hot to cold does not hold any more. At the long time scale, a new dynamic equilibrium is established between the system and the bath. At this equilibrium, the energy of the system can be either higher or lower than its normal equilibrium value. A comprehensive analysis of the relationship between the dynamic equilibrium and the parameters of the modulation as well as the environment is presented.

  6. Open problems in non-equilibrium physics

    International Nuclear Information System (INIS)

    Kusnezov, D.

    1997-01-01

    The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions

  7. The concept of equilibrium in organization theory

    NARCIS (Netherlands)

    Gazendam, H.W.M.

    1998-01-01

    Many organization theories consist of an interpretation frame and an idea about the ideal equilibrium state. This article explains how the equilibrium concept is used in four organization theories: the theories of Fayol, Mintzberg, Morgan, and Volberda. Equilibrium can be defined as balance, fit or

  8. The concept of equilibrium in organization theory

    NARCIS (Netherlands)

    Gazendam, Henk W.M.

    1997-01-01

    Many organization theories consist of an interpretation frame and an idea about the ideal equilibrium state. This article explains how the equilibrium concept is used in four organization theories: the theories of Fayol, Mintzberg, Morgan, and Volberda. Equilibrium can be defined as balance, fit or

  9. Open problems in non-equilibrium physics

    Energy Technology Data Exchange (ETDEWEB)

    Kusnezov, D.

    1997-09-22

    The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions.

  10. Equilibrium and non-equilibrium metal-ceramic interfaces

    International Nuclear Information System (INIS)

    Gao, Y.; Merkle, K.L.

    1992-01-01

    Metal-ceramic interfaces in thermodynamic equilibrium (Au/ZrO 2 ) and non-equilibrium (Au/MgO) have been studied by TEM and HREM. In the Au/ZrO 2 system, ZrO 2 precipitates formed by internal oxidation of a 7%Zr-Au alloy show a cubic ZrO 2 phase. It appears that formation of the cubic ZrO 2 is facilitated by alignment with the Au matrix. Most of the ZrO 2 precipitates have a perfect cube-on-cube orientation relationship with the Au matrix. The large number of interfacial steps observed in a short-time annealing experiment indicate that the precipitates are formed by the ledge growth mechanism. The lowest interfacial energy is indicated by the dominance of closed-packed [111] Au/ZrO 2 interfaces. In the Au/MgO system, composite films with small MgO smoke particles embedded in a Au matrix were prepared by a thin film technique. HREM observations show that most of the Au/MgO interfaces have a strong tendency to maintain a dense lattice structure across the interfaces irrespective of whether the interfaces are incoherent or semi-coherent. This paper reports that this indicates that there may be a relatively strong bond between MgO and Au

  11. Direct transition from a stable equilibrium to quasiperiodicity in non-smooth systems

    DEFF Research Database (Denmark)

    Zhusubaliyev, Z.T.; Mosekilde, Erik

    2008-01-01

    The purpose of this Letter is to show how a border-collision bifurcation in a piecewise-smooth dynamical system can produce a direct transition from a stable equilibrium point to a two-dimensional invariant torus. Considering a system of nonautonomous differential equations describing the behavior...... of a power electronic DC/DC converter, we first determine the chart of dynamical modes and show that there is a region of parameter space in which the system has a single stable equilibrium point. Under variation of the parameters, this equilibrium may collide with a discontinuity boundary between two smooth...... regions in phase space. When this happens, one can observe a number of different bifurcation scenarios. One scenario is the continuous transformation of the stable equilibrium into a stable period-1 cycle. Another is the transformation of the stable equilibrium into an unstable period-1 cycle with complex...

  12. Choking flow modeling with mechanical and thermal non-equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, H.J.; Ishii, M.; Revankar, S.T. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2006-01-15

    The mechanistic model, which considers the mechanical and thermal non-equilibrium, is described for two-phase choking flow. The choking mass flux is obtained from the momentum equation with the definition of choking. The key parameter for the mechanical non-equilibrium is a slip ratio. The dependent parameters for the slip ratio are identified. In this research, the slip ratio which is defined in the drift flux model is used to identify the impact parameters on the slip ratio. Because the slip ratio in the drift flux model is related to the distribution parameter and drift velocity, the adequate correlations depending on the flow regime are introduced in this study. For the thermal non-equilibrium, the model is developed with bubble conduction time and Bernoulli choking model. In case of highly subcooled water compared to the inlet pressure, the Bernoulli choking model using the pressure undershoot is used because there is no bubble generation in the test section. When the phase change happens inside the test section, two-phase choking model with relaxation time calculates the choking mass flux. According to the comparison of model prediction with experimental data shows good agreement. The developed model shows good prediction in both low and high pressure ranges. (author)

  13. Thermal equilibrium in Einstein's elevator.

    Science.gov (United States)

    Sánchez-Rey, Bernardo; Chacón-Acosta, Guillermo; Dagdug, Leonardo; Cubero, David

    2013-05-01

    We report fully relativistic molecular-dynamics simulations that verify the appearance of thermal equilibrium of a classical gas inside a uniformly accelerated container. The numerical experiments confirm that the local momentum distribution in this system is very well approximated by the Jüttner function-originally derived for a flat spacetime-via the Tolman-Ehrenfest effect. Moreover, it is shown that when the acceleration or the container size is large enough, the global momentum distribution can be described by the so-called modified Jüttner function, which was initially proposed as an alternative to the Jüttner function.

  14. Are the Concepts of Dynamic Equilibrium and the Thermodynamic Criteria for Spontaneity, Nonspontaneity, and Equilibrium Compatible?

    Science.gov (United States)

    Silverberg, Lee J.; Raff, Lionel M.

    2015-01-01

    Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

  15. Approach to transverse equilibrium in axial channeling

    International Nuclear Information System (INIS)

    Fearick, R.W.

    2000-01-01

    Analytical treatments of channeling rely on the assumption of equilibrium on the transverse energy shell. The approach to equilibrium, and the nature of the equilibrium achieved, is examined using solutions of the equations of motion in the continuum multi-string model. The results show that the motion is chaotic in the absence of dissipative processes, and a complicated structure develops in phase space which prevent the development of the simple equilibrium usually assumed. The role of multiple scattering in smoothing out the equilibrium distribution is investigated

  16. Equilibrium reconstruction in the TCA/Br tokamak; Reconstrucao do equilibrio no tokamak TCA/BR

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Wanderley Pires de

    1996-12-31

    The accurate and rapid determination of the Magnetohydrodynamic (MHD) equilibrium configuration in tokamaks is a subject for the magnetic confinement of the plasma. With the knowledge of characteristic plasma MHD equilibrium parameters it is possible to control the plasma position during its formation using feed-back techniques. It is also necessary an on-line analysis between successive discharges to program external parameters for the subsequent discharges. In this work it is investigated the MHD equilibrium configuration reconstruction of the TCA/BR tokamak from external magnetic measurements, using a method that is able to fast determine the main parameters of discharge. The thesis has two parts. Firstly it is presented the development of an equilibrium code that solves de Grad-Shafranov equation for the TCA/BR tokamak geometry. Secondly it is presented the MHD equilibrium reconstruction process from external magnetic field and flux measurements using the Function Parametrization FP method. this method. This method is based on the statistical analysis of a database of simulated equilibrium configurations, with the goal of obtaining a simple relationship between the parameters that characterize the equilibrium and the measurements. The results from FP are compared with conventional methods. (author) 68 refs., 31 figs., 16 tabs.

  17. Pre-equilibrium plasma dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Heinz, U.

    1986-01-01

    Approaches towards understanding and describing the pre-equilibrium stage of quark-gluon plasma formation in heavy-ion collisions are reviewed. Focus is on a kinetic theory approach to non-equilibrium dynamics, its extension to include the dynamics of color degrees of freedom when applied to the quark-gluon plasma, its quantum field theoretical foundations, and its relationship to both the particle formation stage at the very beginning of the nuclear collision and the hydrodynamic stage at late collision times. The usefulness of this approach to obtain the transport coefficients in the quark-gluon plasma and to derive the collective mode spectrum and damping rates in this phase are discussed. Comments are made on the general difficulty to find appropriated initial conditions to get the kinetic theory started, and a specific model is given that demonstrates that, once given such initial conditions, the system can be followed all the way through into the hydrodynamical regime. 39 refs., 7 figs. (LEW)

  18. Non-equilibrium phase transition

    International Nuclear Information System (INIS)

    Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.

    1998-01-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken

  19. Pre-equilibrium plasma dynamics

    International Nuclear Information System (INIS)

    Heinz, U.

    1986-01-01

    Approaches towards understanding and describing the pre-equilibrium stage of quark-gluon plasma formation in heavy-ion collisions are reviewed. Focus is on a kinetic theory approach to non-equilibrium dynamics, its extension to include the dynamics of color degrees of freedom when applied to the quark-gluon plasma, its quantum field theoretical foundations, and its relationship to both the particle formation stage at the very beginning of the nuclear collision and the hydrodynamic stage at late collision times. The usefulness of this approach to obtain the transport coefficients in the quark-gluon plasma and to derive the collective mode spectrum and damping rates in this phase are discussed. Comments are made on the general difficulty to find appropriated initial conditions to get the kinetic theory started, and a specific model is given that demonstrates that, once given such initial conditions, the system can be followed all the way through into the hydrodynamical regime. 39 refs., 7 figs

  20. Planar-channeling spatial density under statistical equilibrium

    International Nuclear Information System (INIS)

    Ellison, J.A.; Picraux, S.T.

    1978-01-01

    The phase-space density for planar channeled particles has been derived for the continuum model under statistical equilibrium. This is used to obtain the particle spatial probability density as a function of incident angle. The spatial density is shown to depend on only two parameters, a normalized incident angle and a normalized planar spacing. This normalization is used to obtain, by numerical calculation, a set of universal curves for the spatial density and also for the channeled-particle wavelength as a function of amplitude. Using these universal curves, the statistical-equilibrium spatial density and the channeled-particle wavelength can be easily obtained for any case for which the continuum model can be applied. Also, a new one-parameter analytic approximation to the spatial density is developed. This parabolic approximation is shown to give excellent agreement with the exact calculations

  1. Slope stability analysis using limit equilibrium method in nonlinear criterion.

    Science.gov (United States)

    Lin, Hang; Zhong, Wenwen; Xiong, Wei; Tang, Wenyu

    2014-01-01

    In slope stability analysis, the limit equilibrium method is usually used to calculate the safety factor of slope based on Mohr-Coulomb criterion. However, Mohr-Coulomb criterion is restricted to the description of rock mass. To overcome its shortcomings, this paper combined Hoek-Brown criterion and limit equilibrium method and proposed an equation for calculating the safety factor of slope with limit equilibrium method in Hoek-Brown criterion through equivalent cohesive strength and the friction angle. Moreover, this paper investigates the impact of Hoek-Brown parameters on the safety factor of slope, which reveals that there is linear relation between equivalent cohesive strength and weakening factor D. However, there are nonlinear relations between equivalent cohesive strength and Geological Strength Index (GSI), the uniaxial compressive strength of intact rock σ ci , and the parameter of intact rock m i . There is nonlinear relation between the friction angle and all Hoek-Brown parameters. With the increase of D, the safety factor of slope F decreases linearly; with the increase of GSI, F increases nonlinearly; when σ ci is relatively small, the relation between F and σ ci is nonlinear, but when σ ci is relatively large, the relation is linear; with the increase of m i , F decreases first and then increases.

  2. A new equilibrium torus solution and GRMHD initial conditions

    Science.gov (United States)

    Penna, Robert F.; Kulkarni, Akshay; Narayan, Ramesh

    2013-11-01

    Context. General relativistic magnetohydrodynamic (GRMHD) simulations are providing influential models for black hole spin measurements, gamma ray bursts, and supermassive black hole feedback. Many of these simulations use the same initial condition: a rotating torus of fluid in hydrostatic equilibrium. A persistent concern is that simulation results sometimes depend on arbitrary features of the initial torus. For example, the Bernoulli parameter (which is related to outflows), appears to be controlled by the Bernoulli parameter of the initial torus. Aims: In this paper, we give a new equilibrium torus solution and describe two applications for the future. First, it can be used as a more physical initial condition for GRMHD simulations than earlier torus solutions. Second, it can be used in conjunction with earlier torus solutions to isolate the simulation results that depend on initial conditions. Methods: We assume axisymmetry, an ideal gas equation of state, constant entropy, and ignore self-gravity. We fix an angular momentum distribution and solve the relativistic Euler equations in the Kerr metric. Results: The Bernoulli parameter, rotation rate, and geometrical thickness of the torus can be adjusted independently. Our torus tends to be more bound and have a larger radial extent than earlier torus solutions. Conclusions: While this paper was in preparation, several GRMHD simulations appeared based on our equilibrium torus. We believe it will continue to provide a more realistic starting point for future simulations.

  3. Non-equilibrium magnetic interactions in strongly correlated systems

    Energy Technology Data Exchange (ETDEWEB)

    Secchi, A., E-mail: a.secchi@science.ru.nl [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands); Brener, S.; Lichtenstein, A.I. [Institut für Theoretische Physik, Universitat Hamburg, Jungiusstraße 9, D-20355 Hamburg (Germany); Katsnelson, M.I. [Institute for Molecules and Materials, Radboud University Nijmegen, 6525 AJ Nijmegen (Netherlands)

    2013-06-15

    We formulate a low-energy theory for the magnetic interactions between electrons in the multi-band Hubbard model under non-equilibrium conditions determined by an external time-dependent electric field which simulates laser-induced spin dynamics. We derive expressions for dynamical exchange parameters in terms of non-equilibrium electronic Green functions and self-energies, which can be computed, e.g., with the methods of time-dependent dynamical mean-field theory. Moreover, we find that a correct description of the system requires, in addition to exchange, a new kind of magnetic interaction, that we name twist exchange, which formally resembles Dzyaloshinskii–Moriya coupling, but is not due to spin–orbit, and is actually due to an effective three-spin interaction. Our theory allows the evaluation of the related time-dependent parameters as well. -- Highlights: •We develop a theory for magnetism of strongly correlated systems out of equilibrium. •Our theory is suitable for laser-induced ultrafast magnetization dynamics. •We write time-dependent exchange parameters in terms of electronic Green functions. •We find a new magnetic interaction, a “twist exchange”. •We give general expressions for magnetic noise in itinerant-electron systems.

  4. Stellar Equilibrium in Semiclassical Gravity.

    Science.gov (United States)

    Carballo-Rubio, Raúl

    2018-02-09

    The phenomenon of quantum vacuum polarization in the presence of a gravitational field is well understood and is expected to have a physical reality, but studies of its backreaction on the dynamics of spacetime are practically nonexistent outside of the specific context of homogeneous cosmologies. Building on previous results of quantum field theory in curved spacetimes, in this Letter we first derive the semiclassical equations of stellar equilibrium in the s-wave Polyakov approximation. It is highlighted that incorporating the polarization of the quantum vacuum leads to a generalization of the classical Tolman-Oppenheimer-Volkoff equation. Despite the complexity of the resulting field equations, it is possible to find exact solutions. Aside from being the first known exact solutions that describe relativistic stars including the nonperturbative backreaction of semiclassical effects, these are identified as a nontrivial combination of the black star and gravastar proposals.

  5. Risk premia in general equilibrium

    DEFF Research Database (Denmark)

    Posch, Olaf

    This paper shows that non-linearities can generate time-varying and asymmetric risk premia over the business cycle. These (empirical) key features become relevant and asset market implications improve substantially when we allow for non-normalities in the form of rare disasters. We employ explici......'s effective risk aversion.......This paper shows that non-linearities can generate time-varying and asymmetric risk premia over the business cycle. These (empirical) key features become relevant and asset market implications improve substantially when we allow for non-normalities in the form of rare disasters. We employ explicit...... solutions of dynamic stochastic general equilibrium models, including a novel solution with endogenous labor supply, to obtain closed-form expressions for the risk premium in production economies. We find that the curvature of the policy functions affects the risk premium through controlling the individual...

  6. QUIL: a chemical equilibrium code

    International Nuclear Information System (INIS)

    Lunsford, J.L.

    1977-02-01

    A chemical equilibrium code QUIL is described, along with two support codes FENG and SURF. QUIL is designed to allow calculations on a wide range of chemical environments, which may include surface phases. QUIL was written specifically to calculate distributions associated with complex equilibria involving fission products in the primary coolant loop of the high-temperature gas-cooled reactor. QUIL depends upon an energy-data library called ELIB. This library is maintained by FENG and SURF. FENG enters into the library all reactions having standard free energies of reaction that are independent of concentration. SURF enters all surface reactions into ELIB. All three codes are interactive codes written to be used from a remote terminal, with paging control provided. Plotted output is also available

  7. Pre-equilibrium gamma emissions

    International Nuclear Information System (INIS)

    Ghosh, Sudip

    1993-01-01

    Together with the direct reaction and the compound nuclear emissions the pre-equilibrium (PEQ) or pre-compound processes give a fairly complete picture of nuclear reactions induced by light ions at energies of some tens of MeV. PEQ particle emissions covering the higher energy continuum spectra have been investigated in detail both experimentally and theoretically. In contrast, very little work has been done on PEQ γ- emissions. The reason is that in spite of extensive work done on PEQ particle emissions, the mechanism is not yet fully understood. Also, the PEQ γ-emission cross-sections (∼ micro barns) are very small compared to the PEQ particle emission cross-sections (∼ milli barns). Yet apart from the academic interest the understanding of PEQ γ-emissions is important for applied fusion research etc. In this paper the PEQ γ-emissions is discussed and the work done in this field is reviewed. (author). 14 refs

  8. Equilibrium Analysis in Cake Cutting

    DEFF Research Database (Denmark)

    Branzei, Simina; Miltersen, Peter Bro

    2013-01-01

    Cake cutting is a fundamental model in fair division; it represents the problem of fairly allocating a heterogeneous divisible good among agents with different preferences. The central criteria of fairness are proportionality and envy-freeness, and many of the existing protocols are designed...... to guarantee proportional or envy-free allocations, when the participating agents follow the protocol. However, typically, all agents following the protocol is not guaranteed to result in a Nash equilibrium. In this paper, we initiate the study of equilibria of classical cake cutting protocols. We consider one...... of the simplest and most elegant continuous algorithms -- the Dubins-Spanier procedure, which guarantees a proportional allocation of the cake -- and study its equilibria when the agents use simple threshold strategies. We show that given a cake cutting instance with strictly positive value density functions...

  9. Phase coexistence in thin liquid films stabilized by colloidal particles: equilibrium and non-equilibrium properties

    International Nuclear Information System (INIS)

    Blawzdziewicz, J.; Wajnryb, E.

    2005-01-01

    Phase equilibria between regions of different thickness in thin liquid films stabilized by colloidal particles are investigated using a quasi-two-dimensional thermodynamic formalism. Appropriate equilibrium conditions for the film tension, normal pressure, and chemical potential of the particles in the film are formulated, and it is shown that the relaxation of these parameters occurs consecutively on three distinct time scales. Film stratification is described quantitatively for a hard-sphere suspension using a Monte-Carlo method to evaluate thermodynamic equations of state. Coexisting phases are determined for systems in constrained- and full-equilibrium states that correspond to different stages of film relaxation. We also evaluated the effective viscosity coefficients for two-dimensional compressional and shear flows of a film and the self and collective mobility coefficients of the stabilizing particles. The hydrodynamic calculations were performed using a multiple-reflection representation of Stokes flow between two free surfaces. In this approach, the particle-laden film is equivalent to a periodic system of spheres with a unit cell that is much smaller in the transverse direction than in the lateral direction. (author)

  10. Oppositely charged colloids out of equilibrium

    Science.gov (United States)

    Vissers, T.

    2010-11-01

    Colloids are particles with a size in the range of a few nanometers up to several micrometers. Similar to atomic and molecular systems, they can form gases, liquids, solids, gels and glasses. Colloids can be used as model systems because, unlike molecules, they are sufficiently large to be studied directly with light microscopy and move sufficiently slow to study their dynamics. In this thesis, we study binary systems of polymethylmethacrylate (PMMA) colloidal particles suspended in low-polar solvent mixtures. Since the ions can still partially dissociate, a surface charge builds up which causes electrostatic interactions between the colloids. By carefully tuning the conditions inside the suspension, we make two kinds of particles oppositely charged. To study our samples, we use Confocal Laser Scanning Microscopy (CLSM). The positively and negatively charged particles can be distinguished by a different fluorescent dye. Colloids constantly experience a random motion resulting from random kicks of surrounding solvent molecules. When the attractions between the oppositely charged particles are weak, the particles can attach and detach many times and explore a lot of possible configurations and the system can reach thermodynamic equilibrium. For example, colloidal ‘ionic’ crystals consisting of thousands to millions of particles can form under the right conditions. When the attractions are strong, the system can become kinetically trapped inside a gel-like state. We observe that when the interactions change again, crystals can even emerge again from this gel-like phase. By using local order parameters, we quantitatively study the crystallization of colloidal particles and identify growth defects inside the crystals. We also study the effect of gravity on the growth of ionic crystals by using a rotating stage. We find that sedimentation can completely inhibit crystal growth and plays an important role in crystallization from the gel-like state. The surface

  11. Equilibrium Solubility of CO2 in Alkanolamines

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2014-01-01

    Equilibrium solubility of CO2 were measured in aqueous solutions of Monoethanolamine (MEA) and N,N-diethylethanolamine(DEEA). Equilibrium cells are generally used for these measurements. In this study, the equilibrium data were measured from the calorimetry. For this purpose a reaction calorimeter...... (model CPA 122 from ChemiSens AB, Sweden) was used. The advantage of this method is being the measurement of both heats of absorption and equilibrium solubility data of CO2 at the same time. The measurements were performed for 30 mass % MEA and 5M DEEA solutions as a function of CO2 loading at three...... different temperatures 40, 80 and 120 ºC. The measured 30 mass % MEA and 5M DEEA data were compared with the literature data obtained from different equilibrium cells which validated the use of calorimeters for equilibrium solubility measurements....

  12. Mathematical models and equilibrium in irreversible microeconomics

    Directory of Open Access Journals (Sweden)

    Anatoly M. Tsirlin

    2010-07-01

    Full Text Available A set of equilibrium states in a system consisting of economic agents, economic reservoirs, and firms is considered. Methods of irreversible microeconomics are used. We show that direct sale/purchase leads to an equilibrium state which depends upon the coefficients of supply/demand functions. To reach the unique equilibrium state it is necessary to add either monetary exchange or an intermediate firm.

  13. BOOK REVIEW: Relativistic Figures of Equilibrium

    Science.gov (United States)

    Mars, M.

    2009-08-01

    qualitatively different behaviours. The presentation of the main ideas behind this method is very clear and accessible even to the non-expert. The book then is devoted to presenting both qualitative and quantitative results for a number of models with different equations of state. The case treated more in depth is the constant density case, but results for polytropic equations of state as well as a degenerate ideal gas of neutrons and strange quark matter are also presented. The emphasis is put on the exploration of the parameter space for a fixed equation of state. This is done by studying the various limiting cases involved, namely the non-rotating limit, the Newtonian limit, the mass-shedding limit, the infinite central pressure limit, the transition from one rotating body to several bodies, the black hole limit and the disc limit. The emerging picture in the constant density case is a division of the parameter space into an infinite number of classes, all connected through the Maclaurin spheroids and approaching the limiting case of a Maclaurin disc of dust, which in turn is the Newtonian limit of the relativistic disc of dust. Although the phase space of solutions differs for other equations of state, the main feature of having classes of solutions remains. Despite the inherent complexity and variety of possible behaviours, the authors manage to describe the results in a very lucid manner, and the resulting picture emerges very clearly. The presentation also includes many well-chosen figures, which clarify greatly the understanding of the results and makes this chapter very informative indeed. Furthermore, the book has a related webpage (http://www.tpi.uni-jena.de/gravity/relastro/rfe/) where the source codes for calculating various figures of equilibrium are publicly available. Besides considering single fluids, configurations where a central and very compact object is surrounded by a ring of fluid are also treated to some extent. The central object may be a Newtonian

  14. Equilibrium gas-oil ratio measurements using a microfluidic technique.

    Science.gov (United States)

    Fisher, Robert; Shah, Mohammad Khalid; Eskin, Dmitry; Schmidt, Kurt; Singh, Anil; Molla, Shahnawaz; Mostowfi, Farshid

    2013-07-07

    A method for measuring the equilibrium GOR (gas-oil ratio) of reservoir fluids using microfluidic technology is developed. Live crude oils (crude oil with dissolved gas) are injected into a long serpentine microchannel at reservoir pressure. The fluid forms a segmented flow as it travels through the channel. Gas and liquid phases are produced from the exit port of the channel that is maintained at atmospheric conditions. The process is analogous to the production of crude oil from a formation. By using compositional analysis and thermodynamic principles of hydrocarbon fluids, we show excellent equilibrium between the produced gas and liquid phases is achieved. The GOR of a reservoir fluid is a key parameter in determining the equation of state of a crude oil. Equations of state that are commonly used in petroleum engineering and reservoir simulations describe the phase behaviour of a fluid at equilibrium state. Therefore, to accurately determine the coefficients of an equation of state, the produced gas and liquid phases have to be as close to the thermodynamic equilibrium as possible. In the examples presented here, the GORs measured with the microfluidic technique agreed with GOR values obtained from conventional methods. Furthermore, when compared to conventional methods, the microfluidic technique was simpler to perform, required less equipment, and yielded better repeatability.

  15. Plasma equilibrium response modelling and validation on JT-60U

    International Nuclear Information System (INIS)

    Lister, J.B.; Sharma, A.; Limebeer, D.J.N.; Wainwright, J.P.; Nakamura, Y.; Yoshino, R.

    2002-01-01

    A systematic procedure to identify the plasma equilibrium response to the poloidal field coil voltages has been applied to the JT-60U tokamak. The required response was predicted with a high accuracy by a state-space model derived from first principles. The ab initio derivation of linearized plasma equilibrium response models is re-examined using an approach standard in analytical mechanics. A symmetric formulation is naturally obtained, removing a previous weakness in such models. RZIP, a rigid current distribution model, is re-derived using this approach and is compared with the new experimental plasma equilibrium response data obtained from Ohmic and neutral beam injection discharges in the JT-60U tokamak. In order to remove any bias from the comparison between modelled and measured plasma responses, the electromagnetic response model without plasma was first carefully tuned against experimental data, using a parametric approach, for which different cost functions for quantifying model agreement were explored. This approach additionally provides new indications of the accuracy to which various plasma parameters are known, and to the ordering of physical effects. Having taken these precautions when tuning the plasmaless model, an empirical estimate of the plasma self-inductance, the plasma resistance and its radial derivative could be established and compared with initial assumptions. Off-line tuning of the JT-60U controller is presented as an example of the improvements which might be obtained by using such a model of the plasma equilibrium response. (author)

  16. Non-Equilibrium Solidification of Undercooled Metallic Melts

    Directory of Open Access Journals (Sweden)

    Dieter M. Herlach

    2014-06-01

    Full Text Available If a liquid is undercooled below its equilibrium melting temperature an excess Gibbs free energy is created. This gives access to solidification of metastable solids under non-equilibrium conditions. In the present work, techniques of containerless processing are applied. Electromagnetic and electrostatic levitation enable to freely suspend a liquid drop of a few millimeters in diameter. Heterogeneous nucleation on container walls is completely avoided leading to large undercoolings. The freely suspended drop is accessible for direct observation of rapid solidification under conditions far away from equilibrium by applying proper diagnostic means. Nucleation of metastable crystalline phases is monitored by X-ray diffraction using synchrotron radiation during non-equilibrium solidification. While nucleation preselects the crystallographic phase, subsequent crystal growth controls the microstructure evolution. Metastable microstructures are obtained from deeply undercooled melts as supersaturated solid solutions, disordered superlattice structures of intermetallics. Nucleation and crystal growth take place by heat and mass transport. Comparative experiments in reduced gravity allow for investigations on how forced convection can be used to alter the transport processes and design materials by using undercooling and convection as process parameters.

  17. Thermal equilibrium properties of an intense relativistic electron beam

    International Nuclear Information System (INIS)

    Davidson, R.C.; Uhm, H.S.

    1979-01-01

    The thermal equilibrium properties of an intense relativistic electron beam with distribution function f 0 /sub b/=Z -1 /sub b/exp[-(H-β/sub b/cP/sub z/-ω/sub b/P/sub theta/) /T] are investigated. This choice of f 0 /sub b/ allows for a mean azimuthal rotation of the beam electrons (when ω/sub b/not =0), and corresponds to an important generalization of the distribution function first analyzed by Bennett. Beam equilibrium properties, including axial velocity profile V 0 /sub z/b(r), azimuthal velocity profile V 0 /sub thetab/(r), beam temperature profile T 0 /sub b/(r), beam density profile n 0 /sub b/(r), and equilibrium self-field profiles, are calculated for a broad range of system parameters. For appropriate choice of beam rotation velocity ω/sub b/, it is found that radially confined equilibrium solutions [with n 0 /sub b/(r→infinity) =0] exist even in the absence of a partially neutralizing ion background that weakens the repulsive space-charge force. The necessary and sufficient conditions for radially confined equilibria are ω - /sub b/ + /sub b/ for 0 2 /sub b/p /ω 2 /sub b/c) (1-f-β 2 /sub b/) 2 /sub b/p/ω 2 /sub b/c) (1-f-β 2 /sub b/) <0

  18. Collapse and equilibrium of rotating, adiabatic clouds

    International Nuclear Information System (INIS)

    Boss, A.P.

    1980-01-01

    A numerical hydrodynamics computer code has been used to follow the collapse and establishment of equilibrium of adiabatic gas clouds restricted to axial symmetry. The clouds are initially uniform in density and rotation, with adiabatic exponents γ=5/3 and 7/5. The numerical technique allows, for the first time, a direct comparison to be made between the dynamic collapse and approach to equilibrium of unconstrained clouds on the one hand, and the results for incompressible, uniformly rotating equilibrium clouds, and the equilibrium structures of differentially rotating polytropes, on the other hand

  19. Equilibrium sampling by reweighting nonequilibrium simulation trajectories.

    Science.gov (United States)

    Yang, Cheng; Wan, Biao; Xu, Shun; Wang, Yanting; Zhou, Xin

    2016-03-01

    Based on equilibrium molecular simulations, it is usually difficult to efficiently visit the whole conformational space of complex systems, which are separated into some metastable regions by high free energy barriers. Nonequilibrium simulations could enhance transitions among these metastable regions and then be applied to sample equilibrium distributions in complex systems, since the associated nonequilibrium effects can be removed by employing the Jarzynski equality (JE). Here we present such a systematical method, named reweighted nonequilibrium ensemble dynamics (RNED), to efficiently sample equilibrium conformations. The RNED is a combination of the JE and our previous reweighted ensemble dynamics (RED) method. The original JE reproduces equilibrium from lots of nonequilibrium trajectories but requires that the initial distribution of these trajectories is equilibrium. The RED reweights many equilibrium trajectories from an arbitrary initial distribution to get the equilibrium distribution, whereas the RNED has both advantages of the two methods, reproducing equilibrium from lots of nonequilibrium simulation trajectories with an arbitrary initial conformational distribution. We illustrated the application of the RNED in a toy model and in a Lennard-Jones fluid to detect its liquid-solid phase coexistence. The results indicate that the RNED sufficiently extends the application of both the original JE and the RED in equilibrium sampling of complex systems.

  20. Static Equilibrium Configurations of Charged Metallic Bodies

    African Journals Online (AJOL)

    Key words: Static equilibrium, charged metallic body, potential energy, projected gradient method. ... television, radio, internet, microwave ovens, mobile telephones, satellite communication systems, radar systems, electrical motors, electrical.

  1. Evaluation of indoor radon equilibrium factor using CFD modeling and resulting annual effective dose

    Science.gov (United States)

    Rabi, R.; Oufni, L.

    2018-04-01

    The equilibrium factor is an important parameter for reasonably estimating the population dose from radon. However, the equilibrium factor value depended mainly on the ventilation rate and the meteorological factors. Therefore, this study focuses on investigating numerically the influence of the ventilation rate, temperature and humidity on equilibrium factor between radon and its progeny. The numerical results showed that ventilation rate, temperature and humidity have significant impacts on indoor equilibrium factor. The variations of equilibrium factor with the ventilation, temperature and relative humidity are discussed. Moreover, the committed equivalent doses due to 218Po and 214Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of indoor air. The annual effective dose due to radon short lived progeny from the inhalation of indoor air by the members of the public was investigated.

  2. Near-equilibrium dumb-bell-shaped figures for cohesionless small bodies

    Science.gov (United States)

    Descamps, Pascal

    2016-02-01

    In a previous paper (Descamps, P. [2015]. Icarus 245, 64-79), we developed a specific method aimed to retrieve the main physical characteristics (shape, density, surface scattering properties) of highly elongated bodies from their rotational lightcurves through the use of dumb-bell-shaped equilibrium figures. The present work is a test of this method. For that purpose we introduce near-equilibrium dumb-bell-shaped figures which are base dumb-bell equilibrium shapes modulated by lognormal statistics. Such synthetic irregular models are used to generate lightcurves from which our method is successfully applied. Shape statistical parameters of such near-equilibrium dumb-bell-shaped objects are in good agreement with those calculated for example for the Asteroid (216) Kleopatra from its dog-bone radar model. It may suggest that such bilobed and elongated asteroids can be approached by equilibrium figures perturbed be the interplay with a substantial internal friction modeled by a Gaussian random sphere.

  3. Measurement of use value and non-use value of environmental quality consistent with general equilibrium approach

    OpenAIRE

    Naoki Sakamoto; Kazunori Nakajima

    2014-01-01

    This paper proposes the consistent method with general equilibrium models to measure use value and non-use value of large-scale change in environmental quality. First, we develop a general equilibrium model that parameters of the utility function with environmental quality as a dependent variable can be estimated on the basis of the travel cost method and the contingent variation method. Second, we examine to identify the general equilibrium impact of environmental quality by a comparative st...

  4. CHMTRNS, Non-Equilibrium Chemical Transport Code

    International Nuclear Information System (INIS)

    Noorishad, J.; Carnahan, C.L.; Benson, L.V.

    1998-01-01

    1 - Description of program or function: CHMTRNS simulates solute transport for steady one-dimensional fluid flow by convection and diffusion or dispersion in a saturated porous medium based on the assumption of local chemical equilibrium. The chemical interactions included in the model are aqueous-phase complexation, solid-phase ion exchange of bare ions and complexes using the surface complexation model, and precipitation or dissolution of solids. The program can simulate the kinetic dissolution or precipitation for calcite and silica as well as irreversible dissolution of glass. Thermodynamic parameters are temperature dependent and are coupled to a companion heat transport simulator; thus, the effects of transient temperature conditions can be considered. Options for oxidation-reduction (redox) and C-13 fractionation as well as non-isothermal conditions are included. 2 - Method of solution: The governing equations for both reactive chemical and heat transport are discretized in time and space. For heat transport, the Crank-Nicolson approximation is used in conjunction with a LU decomposition and backward substitution solution procedure. To deal with the strong nonlinearity of the chemical transport equations, a generalized Newton-Raphson method is used

  5. Non-equilibrium thermodynamical description of rhythmic motion patterns of active systems: a canonical-dissipative approach.

    Science.gov (United States)

    Dotov, D G; Kim, S; Frank, T D

    2015-02-01

    We derive explicit expressions for the non-equilibrium thermodynamical variables of a canonical-dissipative limit cycle oscillator describing rhythmic motion patterns of active systems. These variables are statistical entropy, non-equilibrium internal energy, and non-equilibrium free energy. In particular, the expression for the non-equilibrium free energy is derived as a function of a suitable control parameter. The control parameter determines the Hopf bifurcation point of the deterministic active system and describes the effective pumping of the oscillator. In analogy to the equilibrium free energy of the Landau theory, it is shown that the non-equilibrium free energy decays as a function of the control parameter. In doing so, a similarity between certain equilibrium and non-equilibrium phase transitions is pointed out. Data from an experiment on human rhythmic movements is presented. Estimates for pumping intensity as well as the thermodynamical variables are reported. It is shown that in the experiment the non-equilibrium free energy decayed when pumping intensity was increased, which is consistent with the theory. Moreover, pumping intensities close to zero could be observed at relatively slow intended rhythmic movements. In view of the Hopf bifurcation underlying the limit cycle oscillator model, this observation suggests that the intended limit cycle movements were actually more similar to trajectories of a randomly perturbed stable focus. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Equilibrium figures in geodesy and geophysics.

    Science.gov (United States)

    Moritz, H.

    There is an enormous literature on geodetic equilibrium figures, but the various works have not always been interrelated, also for linguistic reasons (English, French, German, Italian, Russian). The author attempts to systematize the various approaches and to use the standard second-order theory for a study of the deviation of the actual earth and of the equipotential reference ellipsoid from an equilibrium figure.

  7. Equilibrium theory of island biogeography: A review

    Science.gov (United States)

    Angela D. Yu; Simon A. Lei

    2001-01-01

    The topography, climatic pattern, location, and origin of islands generate unique patterns of species distribution. The equilibrium theory of island biogeography creates a general framework in which the study of taxon distribution and broad island trends may be conducted. Critical components of the equilibrium theory include the species-area relationship, island-...

  8. Gibbs equilibrium averages and Bogolyubov measure

    International Nuclear Information System (INIS)

    Sankovich, D.P.

    2011-01-01

    Application of the functional integration methods in equilibrium statistical mechanics of quantum Bose-systems is considered. We show that Gibbs equilibrium averages of Bose-operators can be represented as path integrals over a special Gauss measure defined in the corresponding space of continuous functions. We consider some problems related to integration with respect to this measure

  9. Do intertidal flats ever reach equilibrium?

    NARCIS (Netherlands)

    Maan, D.C.; van Prooijen, B.C.; Wang, Z.B.; de Vriend, H.J.

    2015-01-01

    Various studies have identified a strong relation between the hydrodynamic forces and the equilibrium profile for intertidal flats. A thorough understanding of the interplay between the hydrodynamic forces and the morphology, however, concerns more than the equilibrium state alone. We study the

  10. Statistical thermodynamics of equilibrium polymers at interfaces

    NARCIS (Netherlands)

    Gucht, van der J.; Besseling, N.A.M.

    2002-01-01

    The behavior of a solution of equilibrium polymers (or living polymers) at an interface is studied, using a Bethe-Guggenheim lattice model for molecules with orientation dependent interactions. The density profile of polymers and the chain length distribution are calculated. For equilibrium polymers

  11. Non-equilibrium modelling of distillation

    NARCIS (Netherlands)

    Wesselingh, JA; Darton, R

    1997-01-01

    There are nasty conceptual problems in the classical way of describing distillation columns via equilibrium stages, and efficiencies or HETP's. We can nowadays avoid these problems by simulating the behaviour of a complete column in one go using a non-equilibrium model. Such a model has phase

  12. Implementing an Equilibrium Law Teaching Sequence for Secondary School Students to Learn Chemical Equilibrium

    Science.gov (United States)

    Ghirardi, Marco; Marchetti, Fabio; Pettinari, Claudio; Regis, Alberto; Roletto, Ezio

    2015-01-01

    A didactic sequence is proposed for the teaching of chemical equilibrium law. In this approach, we have avoided the kinetic derivation and the thermodynamic justification of the equilibrium constant. The equilibrium constant expression is established empirically by a trial-and-error approach. Additionally, students learn to use the criterion of…

  13. On the definition of equilibrium and non-equilibrium states in dynamical systems

    OpenAIRE

    Akimoto, Takuma

    2008-01-01

    We propose a definition of equilibrium and non-equilibrium states in dynamical systems on the basis of the time average. We show numerically that there exists a non-equilibrium non-stationary state in the coupled modified Bernoulli map lattice.

  14. Information-theoretic equilibrium and observable thermalization

    Science.gov (United States)

    Anzà, F.; Vedral, V.

    2017-03-01

    A crucial point in statistical mechanics is the definition of the notion of thermal equilibrium, which can be given as the state that maximises the von Neumann entropy, under the validity of some constraints. Arguing that such a notion can never be experimentally probed, in this paper we propose a new notion of thermal equilibrium, focused on observables rather than on the full state of the quantum system. We characterise such notion of thermal equilibrium for an arbitrary observable via the maximisation of its Shannon entropy and we bring to light the thermal properties that it heralds. The relation with Gibbs ensembles is studied and understood. We apply such a notion of equilibrium to a closed quantum system and show that there is always a class of observables which exhibits thermal equilibrium properties and we give a recipe to explicitly construct them. Eventually, an intimate connection with the Eigenstate Thermalisation Hypothesis is brought to light.

  15. Disturbances in equilibrium function after major earthquake.

    Science.gov (United States)

    Honma, Motoyasu; Endo, Nobutaka; Osada, Yoshihisa; Kim, Yoshiharu; Kuriyama, Kenichi

    2012-01-01

    Major earthquakes were followed by a large number of aftershocks and significant outbreaks of dizziness occurred over a large area. However it is unclear why major earthquake causes dizziness. We conducted an intergroup trial on equilibrium dysfunction and psychological states associated with equilibrium dysfunction in individuals exposed to repetitive aftershocks versus those who were rarely exposed. Greater equilibrium dysfunction was observed in the aftershock-exposed group under conditions without visual compensation. Equilibrium dysfunction in the aftershock-exposed group appears to have arisen from disturbance of the inner ear, as well as individual vulnerability to state anxiety enhanced by repetitive exposure to aftershocks. We indicate potential effects of autonomic stress on equilibrium function after major earthquake. Our findings may contribute to risk management of psychological and physical health after major earthquakes with aftershocks, and allow development of a new empirical approach to disaster care after such events.

  16. Memory loss process and non-Gibbsian equilibrium solutions of master equations

    International Nuclear Information System (INIS)

    Cataldo, H.M.; Hernandez, E.S.

    1988-01-01

    The phonon dynamics of a harmonic oscillator coupled to a steady reservoir is studied. In the Markovian limit, the equilibrium is reached through a progressive loss of memory process which involves the moments of the initial distribution. The relationship to the non-Markovian equations of motion and its resolvent poles is settled. As a particular model of the coupling mechanism is adopted, the possibility of non-Gibbsian equilibrium distribution arises, which is analyzed focusing upon the dependence of various parameters of the system on an effective equilibrium temperature

  17. Non-equilibrium mean-field theories on scale-free networks

    International Nuclear Information System (INIS)

    Caccioli, Fabio; Dall'Asta, Luca

    2009-01-01

    Many non-equilibrium processes on scale-free networks present anomalous critical behavior that is not explained by standard mean-field theories. We propose a systematic method to derive stochastic equations for mean-field order parameters that implicitly account for the degree heterogeneity. The method is used to correctly predict the dynamical critical behavior of some binary spin models and reaction–diffusion processes. The validity of our non-equilibrium theory is further supported by showing its relation with the generalized Landau theory of equilibrium critical phenomena on networks

  18. Effects of the magnetic equilibrium on gyrokinetic simulations of tokamak microinstabilities

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Weigang; Chen, Yang; Parker, Scott E. [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Groebner, Richard J. [General Atomics, Post Office Box 85068, San Diego, California 92186 (United States)

    2015-06-15

    The general geometry of the experimental tokamak magnetic equilibrium is implemented in the global gyrokinetic simulation code GEM. Compared to the general geometry, the well used Miller parameterization of the magnetic equilibrium is a good approximation in the core region and up to the top of the pedestal. Linear simulations indicate that results with the two geometries agree for r/a ≤ 0.9. However, in the edge region, the instabilities are sensitive to the magnetic equilibrium in both the L-mode and the H-mode plasmas. A small variation of the plasma shaping parameters leads to large changes to the edge instability.

  19. Analysis of equilibrium in a tokamak by the finite-difference method

    International Nuclear Information System (INIS)

    Kim, K.E.; Jeun, G.D.

    1983-01-01

    Ideal magnetohydrodynamic equilibrium in a Tokamak having a small radius with an elongated rectangular cross section is studied by applying the finite-difference method to the Grad-Shafranov equation to determine possible limitations for *b=8*pPsup(2)/Bsup(2). The coupled first-order differential equations resulting from the finite-difference Grad-Shafranov equation is solved by the numarical method:1)We concluded that equilibrium consideration alone gives no limitation even for *b approx.1. 2)We have obtained the equilibrium magnetic field configuration charcterized by a set of three parameters;the aspect ratio, *b,and the safety factor. (Author)

  20. A two-temperature chemical non-equilibrium modeling of DC arc plasma

    International Nuclear Information System (INIS)

    Qian Haiyang; Wu Bin

    2011-01-01

    To a better understanding of non-equilibrium characteristics of DC arc plasma,a two-dimensional axisymmetric two-temperature chemical non-equilibrium (2T-NCE) model is applied for direct current arc argon plasma generator with water-cooled constrictor at atmospheric pressure. The results show that the electron temperature and heavy particle temperature has a relationship under different working parameters, indicating that DC arc plasma has a strong non-equilibrium characteristic, and the variation is obvious. (authors)