WorldWideScience

Sample records for nonmagnetic heavy-mineral concentrates

  1. Regional geochemical maps of the Tonopah 1 degree by 2 degrees Quadrangle, Nevada, based on samples of stream sediment and nonmagnetic heavy-mineral concentrate

    Science.gov (United States)

    Nash, J.T.; Siems, D.F.

    1988-01-01

    This report is part of a series of geologic, geochemical, and geophysical maps of the Tonopah 1° x 2° quadrangle, Nevada, prepared during studies of the area for the Conterminous United States Mineral Assessment Program (CUSMAP). Included here are 21 maps showing the distributions of selected elements or combinations of elements. These regional geochemical maps are based on chemical analyses of the minus-60 mesh (0.25 mm) fraction of stream-sediment samples and the nonmagnetic heavy-mineral concentrate derived from stream sediment. Stream sediments were collected at 1,217 sites. Our geochemical studies of mineralized rock samples provide a framework for evaluating the results from stream sediments.

  2. Heavy mineral concentration from oil sand tailings

    Energy Technology Data Exchange (ETDEWEB)

    Chachula, F.; Erasmus, N. [Titanium Corp. Inc., Regina, SK (Canada)

    2008-07-01

    This presentation described a unique technique to recover heavy minerals contained in the froth treatment tailings produced by oil sand mining extraction operations in Fort McMurray, Alberta. In an effort to process waste material into valuable products, Titanium Corporation is developing technology to recover heavy minerals, primarily zircon, and a portion of bitumen contained in the final stage of bitumen processing. The process technology is being developed to apply to all mined oil sands operations in the Fort McMurray region. In 2004, Titanium Corporation commissioned a pilot research facility at the Saskatchewan Research Council to test dry oil sands tailings. In 2005, a bulk sampling pilot plant was connected to the fresh oil sands tailings pipeline on-site in Fort McMurray, where washed sands containing heavy minerals were processed at a pilot facility. The mineral content in both deposited tailings and fresh pipeline tailings was assessed. Analysis of fresh tailings on a daily basis identified a constant proportion of zircon and higher levels of associated bitumen compared with the material in the deposited tailings. The process flow sheet design was then modified to remove bitumen from the heavy minerals and concentrate the minerals. A newly modified flotation process was shown to be a viable processing route to recover the heavy minerals from froth treatment tailings. 8 refs., 9 tabs., 12 figs.

  3. A process for reducing rocks and concentrating heavy minerals

    Science.gov (United States)

    Strong, Thomas R.; Driscoll, Rhonda L.

    2016-03-30

    To obtain minerals suitable for age-dating and other analyses, it is necessary to first reduce the mineral-bearing rock to a fine, sand-like consistency. Reducing whole rock requires crushing, grinding, and sieving. Ideally, the reduced material should range in size from 80- to 270-mesh (an opening between wires in a sieve). The openings in an 80-mesh sieve are equal to 0.007 inches, 0.177 millimeters, or 177 micrometers. This size range ensures that compound grains are mostly disaggregated and that grains, in general, are dimensionally similar. This range also improves the segregation rate of conspicuous to extremely small individual heavy mineral grains.

  4. Scheme study of separation and concentration of heavy minerals from the black sand in Aguas dulces beach - Rocha

    International Nuclear Information System (INIS)

    Mujica, H.; Marotta, L.

    1968-12-01

    This work is about a study of separation and concentration of heavy minerals from the black sand in Aguas dulces beach - Rocha. The beneficial minerals in that prospected zone are: ilmenite, zircon, rutile and monazite, associated with gangue minerals

  5. Heavy mineral-bearing beach washing concentrates of the West Coast: some observations

    International Nuclear Information System (INIS)

    Pradeep Kumar, T.B.

    2016-01-01

    Beaches are the main sources for economic heavy minerals (HM) like ilmenite rutile, monazite, zircon, garnet and sillimanite. The seasonal HM accumulations, colloquially called 'beach washings' are mined by IREL and KMML in Kerala and by IREL and several private enterprises in Tamil Nadu. These sediments are found to contain 85-90% THM. It is presumed that during the monsoon, the sea is agitated and the churning and spiralling action of water lifts HM-bearing sediments from the sea floor and transports in suspension and deposits on the beach berm, the backwash taking the relatively lighter part of the sediment load back into the sea. This process is thought to give rise to HM-enriched sand on the beach face and the swash plain. It is pertinent to understand the controls on these economically important and scientifically interesting processes. Beachface is the seaward section of a beach exposed to and shaped by the action of waves. The beach face is the zone of most active change. Berm is the terrace of a beach that has formed in the backshore, above the water level at high tide. Berms are commonly found on beaches that have fairly coarse sand and are the result of the deposition of material by low energy waves. On broad beaches there may be three or more sub-parallel berms, each formed under different wave conditions. Swash zone is defined as that part of the beach extending from a nearshore shallow depth to the limit of maximum inundation; is a relatively narrow region of great importance for the exchange of sediment between land and sea. Morphological processes such as storm-induced erosion, post-storm recovery, seasonal variation in foreshore shape, and evolution of rhythmic

  6. Shoreline configurations control on the concentration of nearshore heavy minerals: A case study from Konkan-Maharashtra, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Rajamanickam, G.V.; Wagle, B.G.

    . The Ambolgarh Bay which has the highest concentration is arcuate with gentle gradient. NE-SW orientation appears to be more suitable for the accumulation of more heavy minerals. Wada-Vetye Bay with steep gradient almost oriented in N-S direction and causes...

  7. Heavy mineral survey for uranium in the Philippines

    International Nuclear Information System (INIS)

    Tauchid, M.; Santos, G. Jr.; Hernandez, E.; Bernido, C.

    1983-01-01

    A reconnaissance geochemical survey for uranium was carried out in the island of Samar in the Philippines covering an area of about 13,000 km 2 . The survey represents the first practical demonstration in the country of the use of geochemical techniques to outline large possibly interesting areas within a short period and with modest monetary expenditure. The survey entailed the systematic collection of 1530 heavy mineral concentrates, stream sediments and water samples, and the measurement of radioactivity at 510 stations along the major drainage system of Samar. The average sampling density was 1/20-25 km 2 . All solid samples were analysed for U, Cu, Pb, Zn, Mn, Ag, Co and Ni. Uranium, radon, conductivity and pH were measured in most of the water samples collected. More than 9000 chemical determinations were made. Results of the survey clearly point to the usefulness of heavy mineral sampling at the low density level of observation. The non-magnetic fraction of the heavy mineral concentrates outlined strong and well defined areas of interest for most of the elements analysed. Stream sediment sampling at this sampling density indicated weaker, less clearly defined anomalies. Uranium and radon analyses performed on stream water samples and ground scintillometer readings provided invaluable complementary information relevant to the evaluation of the island's uranium potential. (author)

  8. Elevated concentrations of naturally occurring radionuclides in heavy mineral-rich beach sands of Langkawi Island, Malaysia.

    Science.gov (United States)

    Khandaker, Mayeen Uddin; Asaduzzaman, Khandoker; Sulaiman, Abdullah Fadil Bin; Bradley, D A; Isinkaye, Matthew Omoniyi

    2018-02-01

    Study is made of the radioactivity in the beach sands of Langkawi island, a well-known tourist destination. Investigation is made of the relative presence of the naturally occurring radionuclide 40 K and the natural-series indicator radionuclides 226 Ra and 232 Th, the gamma radiation exposure also being estimated. Sample quantities of black and white sand were collected for gamma ray spectrometry, yielding activity concentration in black sands of 226 Ra, 232 Th and 40 K from 451±9 to 2411±65Bqkg -1 (mean of 1478Bqkg -1 ); 232±4 to 1272±35Bqkg -1 (mean of 718Bqkg -1 ) and 61±6 to 136±7Bqkg -1 (mean of 103Bqkg -1 ) respectively. Conversely, in white sands the respective values for 226 Ra and 232 Th were appreciably lower, at 8.3±0.5 to 13.7±1.4Bqkg -1 (mean of 9.8Bqkg -1 ) and 4.5±0.7 to 9.4±1.0Bqkg -1 (mean of 5.9Bqkg -1 ); 40 K activities differed insubstantially from that in black sands, at 85±4 to 133±7Bqkg -1 with a mean of 102Bqkg -1 . The mean activity concentrations of 226 Ra and 232 Th in black sands are comparable with that of high background areas elsewhere in the world. The heavy minerals content gives rise to elevated 226 Ra and 232 Th activity concentrations in all of black sand samples. Evaluation of the various radiological risk parameters points to values which in some cases could be in excess of recommendations providing for safe living and working. Statistical analysis examines correlations between the origins of the radionuclides, also identifying and classifying the radiological parameters. Present results may help to form an interest in rare-earth resources for the electronics industry, power generation and the viability of nuclear fuels cycle resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Magnetofluidic concentration and separation of non-magnetic particles using two magnet arrays

    Science.gov (United States)

    Hejazian, Majid

    2016-01-01

    The present paper reports the use of diluted ferrofluid and two arrays of permanent magnets for the size-selective concentration of non-magnetic particles. The micro magnetofluidic device consists of a straight channels sandwiched between two arrays of permanent magnets. The permanent magnets create multiple capture zones with minimum magnetic field strength along the channel. The complex interaction between magnetic forces and hydrodynamic force allows the device to operate in different regimes suitable for concentration of non-magnetic particles with small difference in size. Our experimental results show that non-magnetic particles with diameters of 3.1 μm and 4.8 μm can be discriminated and separated with this method. The results from this study could be used as a guide for the design of size-sensitive separation devices for particle and cell based on negative magnetophoresis. PMID:27478527

  10. Heavy minerals : from 'Edelstein' to Einstein

    NARCIS (Netherlands)

    de Meijer, R.J.

    Identification in 1982 on the Dutch Frisian Island of Ameland of beach sand with;ln enhanced level of natural radioactivity, due to concentrations of heavy minerals, inspired a multi-disciplinary research project. A joint research effort in geochemistry, sedimentology, hydrodynamics, solid-state

  11. Economic potential of the heavy minerals of the beaches between Baruva and Bavanapadu, Andhra Pradesh

    International Nuclear Information System (INIS)

    Rajasekhara Reddy, D.; Prasad, V.S.S.; Malathi, V.; Reddy, K.S.N.; Varma, D.D.

    2001-01-01

    The economic potentiality of the heavy minerals in the beaches between Baruva and Bavanapadu extending for about 45 km was examined. In the sub-surface sediments, the heavy minerals were studied at an interval of 1 m up to a maximum depth of 5.8m. In general the concentration of heavy minerals is high in dunes followed by backshore and foreshore regions. Heavy mineral content increases from surface to sub-surface in dunes, decreases in foreshore and does not vary much in backshore. The heavy minerals include mainly ilmenite, garnet, sillimanite and ortho-pyroxenes with minor amounts of amphiboles, zircon, monazite, rutile etc. Majority of the heavies such as ilmenite, monazite, zircon etc. are concentrated in finer fractions while some of the heavies like garnet and sillimanite are concentrated in coarser fractions. The inferred reserves estimated for the area indicate its economical potential. (author)

  12. Recovering byproduct heavy minerals from sand and gravel, placer gold, and industrial mineral operations

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, J.M.; Martinez, G.M.; Wong, M.M.

    1979-01-01

    The Bureau of Mines, as part of an effort to maximize minerals and metals recovery from domestic resources, has investigated the feasibility of recovering heavy minerals as byproducts from sand and gravel, placer gold, and industrial mineral operations in northern California. Sand samples from about 50 locations were treated by gravity separation to yield heavy-mineral cocentrates (black sands). Mineral compositions of the concentrates were determined by chemical analysis and mineralogical examination. Individual zircon, ilmenite, magnetite, platinum-group metals, thoria, and silica products were prepared from heavy-mineral concentrates by selective separation using low- and high-intensity magnetic, high-tension, and flotation equipment.

  13. The application of microtextural and heavy mineral analysis to discriminate between storm and tsunami deposits

    Science.gov (United States)

    Costa, Pedro J.M.; Gelfenbaum, Guy R.; Dawson, Sue; La selle, Seanpaul; Milne, F; Cascalho, J.; Ponte Lira, C.; Andrade, C.; Freitas, M. C.; Jaffe, Bruce E.

    2017-01-01

    Recent work has applied microtextural and heavy mineral analyses to sandy storm and tsunami deposits from Portugal, Scotland, Indonesia and the USA. We looked at the interpretation of microtextural imagery (scanning electron microscopy) of quartz grains and heavy mineral compositions. We consider inundation events of different chronologies and sources (the AD 1755 Lisbon and 2004 Indian Ocean tsunamis, the Great Storm of 11 January 2005 in Scotland, and Hurricane Sandy in 2012) that affected contrasting coastal and hinterland settings with different regional oceanographic conditions. Storm and tsunami deposits were examined along with potential source sediments (alluvial, beach, dune and nearshore sediments) to determine provenance.Results suggest that tsunami deposits typically exhibit a significant spatial variation in grain sizes, microtextures and heavy minerals. Storm deposits show less variability, especially in vertical profiles. Tsunami and storm quartz grains had more percussion marks and fresh surfaces compared to potential source material. Moreover, in the studied cases, tsunami samples had fewer fresh surfaces than storm deposits.Heavy mineral assemblages are typically site-specific. The concentration of heavy minerals decreases upwards in tsunamigenic units, whereas storm sediments show cyclic concentrations of heavy minerals, reflected in the laminations observed macroscopically in the deposits.

  14. Origin and prospectivity of heavy mineral enriched sand deposits along the Somaliland coastal areas

    Science.gov (United States)

    Ali, M. Y.; Hibberd, P.; Stoikovich, B.

    2018-04-01

    Sixty-one heavy mineral enriched samples along the Somaliland coast from Eil Sheikh to Ras Khatib, a distance of about 130 km, were analyzed using X-ray Fluorescence, X-ray Diffraction and SEM-EDS techniques. This study reveals that a considerable amount of heavy minerals is present along the Somaliland coast and confirms the presence of high concentration titanium and iron bearing minerals. However, the backshore deposits in the mouths of Waaheen and Biyo Gure ephemeral rivers as well as raised paleo-beaches in the east of port city of Berbera demonstrate the highest level of titaniferous heavy minerals with most samples showing concentration greater than 50 wt %. The titanium detected in geochemical analysis occurs in the form of ilmenite, rutile, titanite and titaniferous magnetite. Also, present in minor or trace amounts, are garnet, zircon and monazite. Heavy mineral accumulations in the east and west of Berbera have different mineralogical assemblages. The east of Berbera is dominated by quartz with moderate concentration of plagioclase, K-feldspar, magnetite, hematite and titanium bearing minerals, whereas in the west of Berbera, the dominant minerals are quartz, K-feldspar and plagioclase with variable proportions of ilmenite, rutile, mica, amphibole and pyroxene. These variations in mineral assemblages suggest different composition of the catchment areas that supply sediment to these deposits. The catchment area in the east of Berbera consists mainly of Proterozoic crystalline basement of the Qabri Bahar complex, Gabbro-Synenite belt and granitic intrusions that outcrop in Hudiso, Tulo Dibijo and surrounding areas. The primary sources of heavy minerals in the west of Berbera comprise of high-grade metamorphic rocks of the Mora and Qabri Bahar complexes as well as the Miocene volcanics that outcrop in Laferug and Hagabo areas. The heavy mineral sand deposits observed along the Somaliland coast have the potential to provide commercially important heavy

  15. Sedimentology and economic potential of a storm-derived heavy-mineral deposit in the Witteberg group, Cape Province

    Energy Technology Data Exchange (ETDEWEB)

    Cole, D I; Labuschagne, L S

    1982-06-01

    Two heavy-mineral-bearing, very fine-grained sandstone beds occur in the upper part of the Weltevrede Formation of the Witteberg Group, 35 km east-north-east of Willowmore, Cape Province. The beds are located within a 10-m-thick stratigraphic interval approximately 100 m below the base of the Witpoort Formation. The beds are amalgamated and consist of up to 5 units, each representing deposition from a storm-surge ebb current. Nine samples taken from the upper bed and one from the lower were analysed for heavy-mineral content. In order of decreasing abundance the heavy-minerals are rutile, zircon, ilmenite, magnetite, monazite, staurolite and sphene. The zircon contains uranium and the monazite is thorium bearing. Simple linear regression analysis of three elements, three oxides, the heavy mineral fraction and the radiometric response indicate that the proportion of heavy minerals does not vary significantly between samples and that the radiometric response of the beds (determined with a portable gamma-ray scintillometer) is directly related to the heavy mineral content. The heavy minerals are concentrated in the upper 20 cm of each bed where deposition from suspension, during the final phase of storm activity, was predominant. Significant concentrations are limited to the upper bed.

  16. Sedimentology and economic potential of a storm-derived heavy-mineral deposit in the Witteberg group, Cape Province

    International Nuclear Information System (INIS)

    Cole, D.I.; Labuschagne, L.S.

    1982-06-01

    Two heavy-mineral-bearing, very fine-grained sandstone beds occur in the upper part of the Weltevrede Formation of the Witteberg Group, 35 km east-north-east of Willowmore, Cape Province. The beds are located within a 10-m-thick stratigraphic interval approximately 100 m below the base of the Witpoort Formation. The beds are amalgamated and consist of up to 5 units, each representing deposition from a storm-surge ebb current. Nine samples taken from the upper bed and one from the lower were analysed for heavy-mineral content. In order of decreasing abundance the heavy-minerals are rutile, zircon, ilmenite, magnetite, monazite, staurolite and sphene. The zircon contains uranium and the monazite is thorium bearing. Simple linear regression analysis of three elements, three oxides, the heavy mineral fraction and the radiometric response indicate that the proportion of heavy minerals does not vary significantly between samples and that the radiometric response of the beds (determined with a portable gamma-ray scintillometer) is directly related to the heavy mineral content. The heavy minerals are concentrated in the upper 20 cm of each bed where deposition from suspension, during the final phase of storm activity, was predominant. Significant concentrations are limited to the upper bed

  17. Deposit model for heavy-mineral sands in coastal environments: Chapter L in Mineral deposit models for resource assessment

    Science.gov (United States)

    Van Gosen, Bradley S.; Fey, David L.; Shah, Anjana K.; Verplanck, Philip L.; Hoefen, Todd M.

    2014-01-01

    This report provides a descriptive model of heavy-mineral sands, which are sedimentary deposits of dense minerals that accumulate with sand, silt, and clay in coastal environments, locally forming economic concentrations of the heavy minerals. This deposit type is the main source of titanium feedstock for the titanium dioxide (TiO2) pigments industry, through recovery of the minerals ilmenite (Fe2+TiO3), rutile (TiO2), and leucoxene (an alteration product of ilmenite). Heavy-mineral sands are also the principal source of zircon (ZrSiO4) and its zirconium oxide; zircon is often recovered as a coproduct. Other heavy minerals produced as coproducts from some deposits are sillimanite/kyanite, staurolite, monazite, and garnet. Monazite [(Ce,La,Nd,Th)PO4] is a source of rare earth elements as well as thorium, which is used in thorium-based nuclear power under development in India and elsewhere.

  18. Heavy mineral occurrence off Hazira, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Mislankar, P.G.; Gujar, A.R.

    The occurrence of heavy mineral placers on the west coast of India are well known from Konkan and Malabar Coast. However, a geological and geophysical investigation (including echosounding and side scan sonar profiles and 7 samples) off Hazira...

  19. A Weighty Subject: Exploration for Heavy Minerals Across the State of Mississippi

    Science.gov (United States)

    Gifford, J.; Woolsey, A. I.; Yarbrough, L. D.; Platt, B. F.; Widanagamage, I. H.; Easson, G. L.

    2017-12-01

    Preliminary analysis has shown that an array of industrial minerals is known to occur in offshore deposits on the Gulf Coast as well as on-shore deposits in the Upper Cretaceous and Paleogene-Neogene clastic units, such as the Meridian Sand Member of the Eocene Tallahatta Formation in northeastern Mississippi. Furthermore, economic deposits occur within Holocene sediments along the Pearl and Pascagoula Rivers as well as along the modern Gulf of Mexico shoreline. These industrial minerals include suites of heavy minerals (specific gravity ≥2.97) that contain oxides of titanium (ilmenite, rutile, and leucoxene), oxides of zirconium (zircon), and the complex rare-earth-bearing phosphates (monazite and xenotime). These oxides are essential constituents of a wide-range of industrial materials critical to common technologies and the bulk of these mineral commodities are presently dependent on foreign supply. Current offshore deposits have been shown to be economic but are likely no longer accessible given their location within the Gulf Islands National Seashore. This comprehensive study is developing a heavy mineral occurrence dataset for the state of Mississippi including detailed analyses of the industrial mineral resources available within the state. More than 100 samples have been collected across the state from active and non-operating sand pit mining locations. The heavy mineral fraction of each sample was separated using lithium heteropolytungstates (LST) and gravity-based separation techniques. A grain mount for each sample was prepared with the heavy mineral fraction and the percentage values for each heavy mineral species were obtained from 200 grain counts per sample grain mount. Typical heavy mineral fraction for the sample set was approximately 0.9 % with an array from 0.0% to some samples ranging to a greater concentration of 7.5%. The resulting dataset will be further analyzed for geospatial similarities in trends and occurrences. Additional data

  20. Heavy mineral survey for rare earths in the Northern part of Palawan

    International Nuclear Information System (INIS)

    Reyes, R.Y.; Santos, G.P.; Magsambol, W.N.; Ramos, A.F.; Petrache, C.A.; Tabora, E.U.

    1992-01-01

    A reconnaissance geochemical survey for rare earths was carried out over the northern half of Palawan with considerable success. The survey represents the first systematic geochemical exploration effort to look for indigenous rare earth resources in the Philippines. Total area covered was about 5,000 sq km. The survey entailed the systematic collection of 740 heavy mineral panned concentrate and stream sediment samples along streams and rivers. The average sampling density was about one set of sample per 2-15 sq km. A total of 218 heavy mineral samples were analyzed for lathanum, cerium, praseodymium, neodymium and yttrium. Analysis of stream sediments for rare earths was discontinued due to the high detection limit of the X-ray fluorescence spectrometer. Results of the survey clearly indicated the effectiveness of heavy mineral sampling for rare earths at the reconnaissance level of exploration. Six anomalous and well-defined areas of interest were delineated for possible rare earth mineralization. Three priority zones were further outlined from the six prospective areas for possible follow-up surveys. Mineralogical examination of heavy minerals revealed the presence of major allanite and minor monazite as the potential hosts of rare earths in the priority zone number one. Gray monazite was identified in the priority zone number two as the rare earth mineral. Minute specks and grains of gold were visibly present in some of the heavy mineral samples taken in this area. A combined mineralization of rare earths and gold in this area is a possibility. The discovery of the first gray nodular monazite in Palawan may extend the age of the oldest rocks in the Philippines to Lower Paleozoic. A separate study to establish the age of the oldest rocks in the country is likewise necessary. (auth.). 27 refs.; 6 figs.; 8 tabs

  1. The heavy-minerals plant at Palabora Mining Company

    International Nuclear Information System (INIS)

    Van der Spuy, R.C.M.

    1982-01-01

    The heavy-minerals plant at the Palabora Mining Company treats 25 to 30 kt of new feed daily. The U 3 O 8 value of the ore averages approximately 40 p.p.m. The circuit consists of four stages of upgrading on 68 Reichert cones, followed by a jig and 30 table decks. The paper describes how feed-distribution problems have been overcome and the methods used for monitoring and controlling the cone performance. The adaptation of a standard jig for the recovery of fine minerals is discussed, and a method of table agglomeration, for the recovery of coarse refractory copper sulphide is described. The tables consist of polyurethane-covered fibreglass decks, and their operation is controlled according to measurements of the uranothorianite content of the concentrates and middlings by means of a nuclear scintillation counter. The upgrading ratio of the uranium mineral by gravity concentration is 1000:1, baddeleyite (ZrO 2 ) being recovered as a byproduct [af

  2. Role of light and heavy minerals on natural radioactivity level of high background radiation area, Kerala, India.

    Science.gov (United States)

    Ramasamy, V; Sundarrajan, M; Suresh, G; Paramasivam, K; Meenakshisundaram, V

    2014-02-01

    Natural radionuclides ((238)U, (232)Th and (40)K) concentrations and eight different radiological parameters have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. Activity concentrations ((238)U and (232)Th) and all the radiological parameters in most of the sites have higher values than recommended values. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area. In order to know the light mineral characterization of the present sediments, mineralogical analysis has been carried out using Fourier transform infrared (FTIR) spectroscopic technique. The eight different minerals are identified and they are characterized. Among the various observed minerals, the minerals such as quartz, microcline feldspar, kaolinite and calcite are major minerals. The relative distribution of major minerals is determined by calculating extinction co-efficient and the values show that the amount of quartz is higher than calcite and much higher than microcline feldspar. Crystallinity index is calculated to know the crystalline nature of quartz present in the sediments. Heavy mineral separation analysis has been carried out to know the total heavy mineral (THM) percentage. This analysis revealed the presence of nine heavy minerals. The minerals such as monazite, zircon, magnetite and illmenite are predominant. Due to the rapid and extreme changes occur in highly dynamic environments of sandy beaches, quantities of major light and heavy minerals are widely varied from site to site. Granulometric analysis shows that the sand is major content. Multivariate statistical (Pearson correlation, cluster and factor) analysis has been carried out to know the effect of mineralogy on radionuclide concentrations. The present study concluded that heavy minerals induce the (238)U and (232)Th

  3. A shallow marine storm-induced heavy-mineral deposit in the Witteberg group near Willomore, Cape Province

    International Nuclear Information System (INIS)

    Cole, D.I.; Labuschagne, L.S.

    1982-01-01

    Two heavy-mineral-bearing sandstone beds were discovered within the Weltevrede Formation of the Witteberg Group during a routine investigation of an aerial radiometric survey. Maximum concentrations of 142 ppm U and 434 ppm Th were determined by x-ray fluorescence analysis. The sandstone beds that were investigated closely resemble amalgamated storm deposits, each unit representing the product of an individual storm. A radiometric survey indicated that the highest concentration of heavy-minerals are limited to the upper 20 cm of the main bed and the indicated resources are as follows: rutile - 2700 tons, zircon - 850 tons, ilmenite - 650 tons, magnetite - 550 tons, monozite - 200 tons, and uranium - 5 tons

  4. Heavy mineral potential of Ramnad Sub-basin, Tamil Nadu

    International Nuclear Information System (INIS)

    Shaji, T.S.; Alam, M.

    2016-01-01

    Atomic Minerals Directorate for the Exploration and Research (AMD) is actively engaged in the surveys and exploration of heavy mineral placers along 980 km long coast of Tamil Nadu since 1950's identifying many major heavy mineral deposits/occurrences of varying grade and dimensions in the beach, coastal dunes and Teri sand environs. Though most of the coastal stretch of Tamil Nadu is fairly understood for its heavy mineral potential, some of the coastal segments of the Ramnad basin of southeastern Tamil Nadu, a storehouse of heavy mineral placer repositories need intensive exploration inputs, to understand its potential completely. The 100 km long study area falls in parts of Ramnad sub basin from Vaippar in Tuticorin to Mandapam in Ramanathpuram districts, constitutes the southern part of Cauvery basin. The unconsolidated coastal sediments of the basin is under active exploration and evaluation since 2012, in a phased manner, to link the known deposits, and completely delineate geo-spatial disposition of the heavy mineral bearing sand bodies in different environs right from the present day shoreline to the inland. Geologically, the area is a part of a long narrow strip of Tertiary/Quaternary sediments which outcrops along the southern Tamil Nadu coast. Precambrian granulites terrain of Southern Granulitic Terrain (SGT) in the hinterland area consisting of predominantly charnockites, gneisses, leptynites with numerous pegmatitic, vein quartz injections. The geomorphological features identified include Holocene Beach ridges, swales, abandoned channels, coastal dunes, and alluvial delta plains of Vaippar

  5. Reconnaisance geochemical survey of heavy minerals in Northern Luzon, Philippines

    International Nuclear Information System (INIS)

    Santos, G. Jr.; Seguis, J.E.; Fernandez, L.G.

    1983-07-01

    A reconnaissance sampling was undertaken in northern Luzon to study the distribution of uranium as well as copper, lead, zinc, manganese, silver, cobalt and nickel in heavy minerals. The average background and threshold values of the elements were determined. Uranium content in the heavy mineral was low, in the order of 0.5-0.6 ppm U. Three uranium anomaly zones were delineated in Malanas Rever-Licuan area, Abra, Itogon, Benguet and Bambang, Nueva Viscaya, all within the Central Cordillera. The anomalous zones appeared to be related to copper-gold mineral areas. Geochemical correlations between uranium and the other elements were generally poor. (author)

  6. Attribute analyses of gpr data for detecting and identifying heavy minerals

    Science.gov (United States)

    Catakli, Aycan

    Attribute analyses have been used successfully in seismic applications for many years. In this study, the application of the attribute analyses to Ground Penetrating Radar (GPR) data has been proposed to detect and identify heavy minerals within the Moon soil (regolith). Lunar samples are mostly composed of heavy minerals such as ilmenite, plagioclase, olivine and pyroxene, a characteristic that makes lunar soil a source for elements such as titanium, oxygen and iron. The main goal of this study is to demonstrate the use of GPR method for detecting and mapping heavy minerals concentrations. The attribute analyses used in this study are Attenuation Analysis (AA), Complex Trace Analysis (CTA), Texture Analysis (TA) and Center Frequency Destitution (CFD). Attribute analysis was applied to both synthetic models and prototype laboratory measurements to study its application to GPR data. The results indicate that the attribute analyses of GPR data can be useful to provide valuable subsurface information. The findings of AA show that attenuation values are function of mineralogy of the subsurface. This could be applicable to Moon and Mars in addition to Earth environment to explore their near-surface soils. CTA can successfully estimate the location of heavy mineral samples embedded inside host medium through the variation of reflected energy around buried sample and sharpen the reflecting interface. Results indicate that as the amount of the buried heavy minerals increases, the value of CTA parameters (Normal distribution of amplitude spectra `NDoAS' and tau-parameter) proportionally increase. TA measures combined can be used as an enhanced interpretation tool. The texture results show that heavy mineral concentrations can be identified by the high contrast, entropy, autocorrelation, correlation, cluster, dissimilarity, standard deviation, variance and low energy, maximum probability, and homogeneity. The measures also help in highlighting the edge of the buried samples

  7. The geochemistry of some selected South African kimberlites and associated heavy minerals

    International Nuclear Information System (INIS)

    Fesq, H.W.; Kable, E.J.D.; Gurney, J.J.

    1976-01-01

    63 Kimberlite samples from 3 geographically different localities, namely, Premier (Transvaal), Koffiefontein (Orange Free State), and Bellsbank (northern Cape), were analysed by x-ray-fluorescence and instrumental neutron-activation analysis (INAA). Kimberlitic heavy minerals from eighteen different South African sources were analysed by INAA in an attempt to establish whether there are geochemical criteria for distinguishing diamondiferous kimberlites from kimberlites that are not economically diamondiferous. For the purposes of diamond exploration, analyses of kimberlite-indicator minerals, e.g., pyrope garnet, chromium diopside, picro-ilmenite, and chromium spinels, are regarded as providing a more profitable approach than the analysis of kimberlites per se. If the statistically small sample population investigated and the complicating problem of crustal contamination are taken into account, no direct indication of the diamond-bearing potential of kimberlites can be obtained from analyses of bulk rock. On the other hand, there appears to be a close correlation between the chromium content of kimberlite heavy minerals, the abundance of chromium spinels in the heavy-mineral concentrate, and the diamond-bearing potential of the source kimberlite. These preliminary findings should be confirmed on a larger sample population that includes more non-diamondiferous sources. It is preferable that analyses should be done on single grains, and they should include major elements (by electron-microprobe analysis) as well as minor and trace elements [af

  8. Identification of provenance rocks based on EPMA analyses of heavy minerals

    Science.gov (United States)

    Shimizu, M.; Sano, N.; Ueki, T.; Yonaga, Y.; Yasue, K. I.; Masakazu, N.

    2017-12-01

    Information on mountain building is significant in the field of geological disposal of high-level radioactive waste, because this affects long-term stability in groundwater flow system. Provenance analysis is one of effective approaches for understanding building process of mountains. Chemical compositions of heavy minerals, as well as their chronological data, can be an index for identification of provenance rocks. The accurate identification requires the measurement of as many grains as possible. In order to achieve an efficient provenance analysis, we developed a method for quick identification of heavy minerals using an Electron Probe Micro Analyzer (EPMA). In this method, heavy mineral grains extracted from a sample were aligned on a glass slide and mounted in a resin. Concentration of 28 elements was measured for 300-500 grains per sample using EPMA. To measure as many grains as possible, we prioritized swiftness of measurement over precision, configuring measurement time of about 3.5 minutes for each grain. Identification of heavy minerals was based on their chemical composition. We developed a Microsoft® Excel® spread sheet input criteria of mineral identification using a typical range of chemical compositions for each mineral. The grains of 110 wt.% total were rejected. The criteria of mineral identification were revised through the comparison between mineral identification by optical microscopy and chemical compositions of grains classified as "unknown minerals". Provenance rocks can be identified based on abundance ratio of identified minerals. If no significant difference of the abundance ratio was found among source rocks, chemical composition of specific minerals was used as another index. This method was applied to the sediments of some regions in Japan where provenance rocks had lithological variations but similar formation ages. Consequently, the provenance rocks were identified based on chemical compositions of heavy minerals resistant to

  9. Radiogenic heavy minerals in Brazilian beach sand

    International Nuclear Information System (INIS)

    Malanca, A.

    1998-01-01

    Sand samples collected on the beaches of the 'radioactive' Brazilian town of Guarapari were first separated by flotation in bromoform and successively divided into various magnetic fractions with a Franz isodynamic separator. concentrations of background radionuclides in samples of monazite, ilmenite, and zircon were determined by a γ-ray spectrometer. Chemical composition of monazite, ilmenite and magnetite were assessed by means of an electron microprobe. Monazite resulted to be relatively rich in ThO 2 whose abundance ranged from 5.3 to 7.7 (wt%). (author)

  10. Heavy mineral analyses as a powerful tool in fluvial geomorphology

    Science.gov (United States)

    von Suchodoletz, Hans; Gärtner, Andreas; Faust, Dominik

    2014-05-01

    The Marneuli depression is a tectonic sub-basin of the Transcaucasian depression in eastern Georgia, filled with several decametres of fluvial, lacustrine and aeolian Quaternary sediments. In order to reconstruct past landscape evolution of the region we studied Late Quaternary fluvial sediments found along several rivers that flow through that depression. Whereas Holocene river sediments could generally easily be assigned to corresponding rivers, this was not always the case for older fluvial sediments. For this reason, we studied the heavy mineral contents of five recent rivers and of four sedimentary deposits of potential precursors. A total of 4088 analysed heavy mineral grains enabled us to set up the characteristic heavy mineral distribution pattern for each sample. Using these data, we were able to reconstruct the most likely source areas of the Late Pleistocene fluvial sediments and to link them with the catchment areas of recent rivers. This allowed us to identify and to substantiate significant Late Quaternary river diversions that could at least partly be assigned to ongoing tectonic processes.

  11. Radionuclides and radiation doses in heavy mineral sands and other mining operations in Mozambique

    International Nuclear Information System (INIS)

    Carvalho, F. P.; Matine, O. F.; Taimo, S.; Oliveira, J. M.; Silva, L.; Malta, M.

    2014-01-01

    Sites at the littoral of Mozambique with heavy mineral sands exploited for ilmenite, rutile and zircon and inland mineral deposits exploited for tantalite, uranium and bauxite were surveyed for ambient radiation doses, and samples were collected for the determination of radionuclide concentrations. In heavy mineral sands, 238 U and 232 Th concentrations were 70±2 and 308±9 Bq kg -1 dry weight (dw), respectively, whereas after separation of minerals, the concentrations in the ilmenite fraction were 2240±64 and 6125±485 Bq kg -1 (dw), respectively. Tantalite displayed the highest concentrations with 44 738±2474 Bq kg -1 of 238 U. Radiation exposure of workers in mining facilities is likely to occur at levels above the dose limit for members of the public (1 mSv y -1 ) and therefore radiation doses should be assessed as occupational exposures. Local populations living in these regions in general are not exposed to segregated minerals with high radionuclide concentrations. However, there is intensive traditional mining and a large number of artisan miners and their families may be exposed to radiation doses exceeding the dose limit. A radiation protection programme is therefore needed to ensure radiation protection of the public and workers of developing mining projects. (authors)

  12. Radionuclides and radiation doses in heavy mineral sands and other mining operations in Mozambique.

    Science.gov (United States)

    Carvalho, Fernando P; Matine, Obete F; Taímo, Suzete; Oliveira, João M; Silva, Lídia; Malta, Margarida

    2014-01-01

    Sites at the littoral of Mozambique with heavy mineral sands exploited for ilmenite, rutile and zircon and inland mineral deposits exploited for tantalite, uranium and bauxite were surveyed for ambient radiation doses, and samples were collected for the determination of radionuclide concentrations. In heavy mineral sands, (238)U and (232)Th concentrations were 70±2 and 308±9 Bq kg(-1) dry weight (dw), respectively, whereas after separation of minerals, the concentrations in the ilmenite fraction were 2240±64 and 6125±485 Bq kg(-1) (dw), respectively. Tantalite displayed the highest concentrations with 44 738±2474 Bq kg(-1) of (238)U. Radiation exposure of workers in mining facilities is likely to occur at levels above the dose limit for members of the public (1 mSv y(-1)) and therefore radiation doses should be assessed as occupational exposures. Local populations living in these regions in general are not exposed to segregated minerals with high radionuclide concentrations. However, there is intensive artisanal mining and a large number of artisanal miners and their families may be exposed to radiation doses exceeding the dose limit. A radiation protection programme is therefore needed to ensure radiation protection of the public and workers of developing mining projects.

  13. Potential of heavy minerals in the Valenca-Itacare, Bahia (Brazil) region - Sampling characterization and ore processing

    International Nuclear Information System (INIS)

    Noguti, I.; Feitosa, J.A.

    1989-01-01

    Important heavy minerals deposits were discovered by CBPM in the townships of Nilo Pecanha and Marau, state of Bahia. Ore dressing tests were conducted at CETEC and the results indicate a good potential. Tests were carried out with the Humphreys spiral, with magnetic and electro-static separators were yielding concentrates of ilmenite with 56.0% TiO 2 and Zircon with 65.0% ZrO 2 . (author) [pt

  14. Pinning in nonmagnetic borocarbides

    International Nuclear Information System (INIS)

    Zholobenko, A.N.; Mikitik, G.P.; Fil, V.D.; Kim, J.D.; Lee, S.I.

    2005-01-01

    The field dependences of the Labush parameter in nonmagnetic borocarbides are measured by the method which does not require the free flux flow regime. The anticipated critical current densities are estimated. These values are by two orders of magnitude higher than those measured 'directly' in transport (magnetic) experiments. The giant peak-effect in the field dependences of the Labush parameter is revealed in the Y-based borocarbides. Its behavior is well approximated by the collective pinning theory

  15. ESTIMATE OF THE HEAVY MINERAL-CONTENT IN SAND AND ITS PROVENANCE BY RADIOMETRIC METHODS

    NARCIS (Netherlands)

    DEMEIJER, RJ; LESSCHER, HME; SCHUILING, RD; ELBURG, ME

    1990-01-01

    A comparison has been made of the traditional gravimetric method for measuring the heavy mineral mass fraction in sand with a method based on the emission of gamma-rays from the uranium and thorium series by radiogenic heavy-minerals. The comparision reveals that beach sand along the Dutch coast may

  16. Radiometric characteristics of heavy mineral deposits along the west coast of South Africa

    NARCIS (Netherlands)

    Macdonald, W.G.; Rozendaal, A.; de Meijer, R.J.

    During the last decade, exploration and mining of modern-Tertiary heavy mineral beach and raised beach sands along the west coast of South Africa has developed into a major industry. High resolution radiometric techniques have demonstrated their use as a quantitative indicator of total heavy mineral

  17. Heavy mineral delineation of the Cretaceous, Paleocene, and Eocene stratigraphic sections at the Savannah River Site, Upper Coastal Plain of South Carolina

    International Nuclear Information System (INIS)

    Cathcart, E.M.; Sargent, K.A.

    1994-01-01

    The Upper Atlantic Coastal Plain of South Carolina consists of a fluvial-deltaic and shallow marine complex of unconsolidated sediments overlying the crystalline basement rocks of the North American continent. Because of the lateral and vertical variability of these sediments, stratigraphic boundaries have been difficult to distinguish. Portions of the Cretaceous, Paleocene, and eocene stratigraphic sections from cores recovered during the construction of two monitoring wells at the Savannah River Site were studied to determine if heavy mineral suites could be utilized to distinguish boundaries. The stratigraphic sections include: the Late Cretaceous Middendorf, Black Creek, and Steel Creek Formations, the Paleocene Snapp Formation, the late Paleocene-Early Eocene Fourmile Branch Formation, and the Early Eocene Congaree formation. In previous studies composite samples were taken over 2.5 ft. intervals along the cores and processed using a heavy liquid for heavy mineral recovery. During this study, heavy mineral distributions were determined by binocular microscope and the mineral identifications confirmed by x-ray diffraction analysis of hand-picked samples. The heavy mineral concentration data and grain size data were then compared to the stratigraphic boundary positions determined by other workers using more classical methods. These comparisons were used to establish the utility of this method for delineating the stratigraphic boundaries in the area of study

  18. Titanium mineral resources in heavy-mineral sands in the Atlantic coastal plain of the southeastern United States

    Science.gov (United States)

    Van Gosen, Bradley S.; Ellefsen, Karl J.

    2018-04-16

    This study examined titanium distribution in the Atlantic Coastal Plain of the southeastern United States; the titanium is found in heavy-mineral sands that include the minerals ilmenite (Fe2+TiO3), rutile (TiO2), or leucoxene (an alteration product of ilmenite). Deposits of heavy-mineral sands in ancient and modern coastal plains are a significant feedstock source for the titanium dioxide pigments industry. Currently, two heavy-mineral sands mining and processing operations are active in the southeast United States producing concentrates of ilmenite-leucoxene, rutile, and zircon. The results of this study indicate the potential for similar deposits in many areas of the Atlantic Coastal Plain.This study used the titanium analyses of 3,457 stream sediment samples that were analyzed as part of the U.S. Geological Survey’s National Geochemical Survey program. This data set was analyzed by an integrated spatial modeling technique known as Bayesian hierarchical modeling to map the regional-scale, spatial distribution of titanium concentrations. In particular, clusters of anomalous concentrations of titanium occur: (1) along the Fall Zone, from Virginia to Alabama, where metamorphic and igneous rocks of the Piedmont region contact younger sediments of the Coastal Plain; (2) a paleovalley near the South Carolina and North Carolina border; (3) the upper and middle Atlantic Coastal Plain of North Carolina; (4) the majority of the Atlantic Coastal Plain of Virginia; and (5) barrier islands and stretches of the modern shoreline from South Carolina to northeast Florida. The areas mapped by this study could help mining companies delimit areas for exploration.

  19. Heavy minerals and provenance of the paleozoic suffi formation, Western desert, iraq.

    OpenAIRE

    Al Juboury, Ali I. [علي الجبوري; Hassan, Zeki M.

    1996-01-01

    Heavy minerals analyses were carried out on 10 samples from the clastic Suffi Formation (the Ordovician-Carboniferous unit in the western Iraqi desert). The suite of minerals consists mainly of opaque minerals including pyrite, ilmenite, magnetite and hematite and the non-opaques is represented by zircon, tourmaline, cutile, garnet, epidote, kyanite, staurolite, leucoxene, chlorite and biotite. The nature and occurrence of the above heavy minerals association reflect a source area of the crys...

  20. Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov

    2011-01-01

    Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and has been recently recognised as a significant modifier of deep-water sandstone geometry. Large-scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon...... of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional...... sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downward injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic...

  1. Radiostratigraphy and heavy mineral content of the Weches Formation (Eocene), Nacogdoches County, Texas

    International Nuclear Information System (INIS)

    Jobe, K.; Ledger, E.B.; Sharp, P.; Crocker, M.C.

    1993-01-01

    The Weches Formation of eastern Texas is a mudstone containing green sand-size clay aggregates. A vertical sequence of 43 samples was analyzed along an excavated cliff to determine radionuclide content. Samples average 5 ppm uranium and range from 2 to about 7 ppm. Thorium averages 20 ppm and ranges from 13 to almost 36 ppm. the gamma-ray spectrometer employed exhibits a certainty of about ±10% (one standard deviation) at the levels measured. Heavy mineral studies of mudstones are few, so one sample of the Weches mudstone was selected for heavy mineral separation and point counting of grain mounts. A total of 2606 grains were counted giving mineral percentages of zircon (28.8%), garnet (17.9%), tourmaline (10.5%), titanite (8.7%), apatite (7.6%), staurolite (6.4%), green hornblende (5.2%), epidote (5.1%), sillimanite (2.8%), monatite (2.2%), kyanite (1.9%), basaltic hornblende (1.5%), and biotite (1.3%). In addition, actinolite, spinel, rutile, and collophane were observed but not counted. Previous studies found a similar heavy mineral suite in the underlying Queen City Formation, but in different proportions. Differences in heavy mineral percentages probably reflect different water-flow regimes at the time of deposition. Heavy minerals in the Weches and Queen City formations are from the same general source area Measured radionuclide ratios are similar to granitic ratios and suggest that detrital heavy minerals, particularly zircon and monazite, are the main site of uranium and thorium and their decay products in the Weches Formation

  2. Nonmagnetic driver for piezoelectric actuators

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh

    2014-01-01

    actuator drive is the only form-fit continuous drive solution currently available for the development of high performance nonmagnetic motors. In this research focus will be on the non magnetic compact high efficiency driver for the piezo actuators and on employing energy recovery from the capacitive...

  3. Nonmagnetic impurities in magnetic superconductors

    International Nuclear Information System (INIS)

    Mineev, V.P.

    1989-01-01

    The magnetization and magnetic field arising around the nonmagnetic impurity in magnetic superconductor with triplet pairing are found. The relationship of these results with the data of recent (gm)sR experiments in heavy fermionic superconductor U 1 - x Th x Be 13 is presented

  4. Optimal Inference of Modelling Parameters to Simulate Complex Trends across Soft Boundaries : A Case Study in Heavy Mineral Sands

    NARCIS (Netherlands)

    Wambeke, T.; Benndorf, J.

    2014-01-01

    A risk-robust development of a heavy mineral resource requires an assessment of the geological uncertainty and spatial variability of the key factors impacting the mining and processing operation. Attributes of interest are the total heavy mineral grade, the slime content and the amount of oversized

  5. The tin mining and heavy mineral processing industry in the Kinta Valley, Perak, Malaysia

    International Nuclear Information System (INIS)

    Lee Swee Ching

    1994-01-01

    Overview of the tin mining and heavy mineral processing in the Kinta Valley, Perak, Malaysia was presented. Amang, a mixture composed of tin ore, sand, ilmenite, monazite, zircon, xenotime, struvite, etc , as a product from tin mining activities was discussed too in this paper

  6. Heavy mineral distribution in the beaches of Nagapattinam District, Tamilnadu, India

    Digital Repository Service at National Institute of Oceanography (India)

    Angusamy, N.; Manickaraj, D.S.; Chandrasekaran, R.; Chandrasekar, N.; Loveson, V.J.; Gujar, A.R.; Rajamanickam, G.V.

    -tsunami samples Chinnankudi an upshoot of heavies to a tune of 93% in the Berm of Nagoor and HT of Chinnankudi. At Poompuhar, the distributions of heavy minerals are found to be different to other two stations. While Poompuhar establishes overall rise in the Wt...

  7. Study on the behavior of naturally occurring radioactivity originated from heavy minerals in weathering process of granite

    International Nuclear Information System (INIS)

    Nakano, M.; Nakashima, Y.

    1993-01-01

    Mass fraction of biotite and of heavy minerals originally in granite rocks at Naegi granite area are 3% and 1 x 10 -4 %, respectively. Though their values are very small, specific activities of 238 U is 1.3 Bq/g and 80 Bq/g, respectively. Their values are much higher than that of gross granite (0.1 Bq/g). Therefore, they play important roles in the weathering process. Authors separated biotite and heavy minerals from less-weathered and weathered (outcrop, plastic materials) granite samples by using heavy liquid, and determined each specific activities and activity ratios. Furthermore, the surface of heavy minerals were washed in 6 N HCl for 20 minutes. And lost fraction of activity in the heavy minerals was determined. The result suggested that activity around heavy mineral's surface was removed into surroundings or external environment through weathering process. (5 figs.)

  8. Geochemical radioactive investigation of beach sands and stream sediments, using heavy minerals, trace elements and radon measurements, (Qerdaha sheet of the Syrian coast)

    International Nuclear Information System (INIS)

    Jubeli, Y.; Kattaa, B.; Al-Hilal, M.

    2000-05-01

    Reconnaissance geochemical radiometric survey of stream sediments resulting from the weathering of outcropped rocks in and around the study area was performed. This survey included heavy mineral sampling, trace and radioelements and radon measurements to evaluate the radioactivity of the source rocks and to understand the nature and distribution of the heavy minerals and trace elements in the study area. Several techniques were used to achieve these objectives. The results of heavy mineral geochemical survey show that the abundant minerals are iron oxides (magnetite, hematite, goehtite and limonite) pyroxene and olivine; less abundant minerals are apatite, ilmenite, garnet, barite, siderite and gloconite, while rare minerals are zircon and rutile. Amphibole is reported as an abundant mineral in sand dunes and is less abundant in samples located in the northern part of the study area. The amphibole seems to be derived from the ophiolitic complex north of the study area. Grain size analysis of heavy minerals revealed that the concentration of economic minerals such as zircon rutile and ilmenite increases with the decrease of the grain size. The microscopic study showed fragments and fossils of foraminifere mostly impregnated with heavy metals such as iron and manganese resulting from diagenetic metasomatism and replacement processes of. Fish teeth (< 2 mm) and oolite of iron were also noticed in most of the samples. The morphology of heavy mineral grains shows that most of the grains are angular to subangular suggesting that they were transported for short distance from their source rocks. Normally, phosphate pellets, gloconite and iron ooids are not considered since their original morphological features show clear roundness that attributed to their sedimentological origin, not to transportation factor. The source rock of most of the heavy mineral assemblage is the basalt. Apatite and gloconite are derived from the phosphorite and phosphatized limestone encountered

  9. HEAVY MINERALS IN PLACER DEPOSIT IN SINGKAWANG WATERS, WEST Kalimantan, RELATED TO FELSIC SOURCE ROCK OF ITS COASTAL AREA

    Directory of Open Access Journals (Sweden)

    Deny Setiady

    2017-07-01

    Full Text Available Placer deposits are physically accumulated by fluvial and marine processes in coastal area. Thirty six samples were selected from seventy seven samples of seafloor sediment of Singkawang waters. Those samples have been analyzed microscopically for heavy mineral contents. Based on this analysis, the heavy minerals can be divided into four groups: oxyde and hydroxyde, silicate, sulphide, and carbonate. The source of most heavy minerals in the study area is commonly formed by Felsic igneous rock and finally deposited on the seafloor sediments.

  10. Mineralogy and Genesis of Heavy Minerals in Coastal Dune Sands, South Eastern Qatar

    OpenAIRE

    Nasir, Sobhi J. [صبحي جابر نصر; El-Kassas, Ibrahim A.; Sadiq, A. Ali M.

    1999-01-01

    Large amounts of aeolian sand occur in the southeastern coastal zone of Qatar Peninsula as sand dunes accumulated in a vast sand field locally called " Niqyan Qatar ". The present work, carried out on a sand dune belt of this field near Mesaied Industrial City, revealed the distribution of heavy minerals shows a regional variability induced by provenance and local variability reflecting genetic differences. The studied dune sands are rich in shells of pelecypods, with the light mineral assemb...

  11. Radioactivity of heavy minerals and geochemistry of trace elements and radon, resulting from the weathering of the ophiolitic complex, Northwest of Syria

    International Nuclear Information System (INIS)

    Kattaa, B.; Al-Hilal, M.; Jubeli, Y.

    1999-06-01

    Geochemical and radiometric survey of stream sediments resulting from the weathering of ophiolitic complex at Al-Basit area were carried out. Several exploration techniques have been used to evaluate the radioactive elements and minerals in the area, and to estimate the significance of the radioactivity of the source rocks of these elements and minerals. determination of radioelements and some trace elements in stream sediments, in addition to gamma-ray spectrometry and radon gas measurement in water of springs and wells were carried out in the study area. The results show that the high values of radioactive elements and radon concentration are related to the occurrence of syenite nepheline and plageogranite, characterized by higher content of these elements compared to mafic and ultramafic rocks. Mineralogical study of the heavy minerals shows that the abundant minerals are pyroxene and amphibole, while less abundant minerals are iron oxides (limonite and hematite), chromite, ilmenite, olivine and magnetite. Rare minerals are zircon, apatite, barite, tourmaline and sphen. The absence of monazite, xenotime and thorite in the collected samples is mainly attributed to the very limited occurrence of their source rocks. However, this results is rather restricted to the collected samples. High concentration of magnetite and ilmenite in some samples was noted, in addition to the presence of mineral called galaxite which was not reported previously. Gold flake was also found in one of the samples. The study of grain morphology suggests that the heavy minerals were transported for short distance from their source rocks. Grain size analyse of heavy minerals reveals that the concentration of economic minerals such as chromite and ilmenite increases with the decrease of the grain size. (author)

  12. Heavy minerals in the sediments on the outer continental shelf between Vengurla and Mangalore on the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kidwai, R.M.; Nair, R.R.; Hashimi, N.H.

    Fifty-eight sediment samples from the outer continental shelf between Vengurla and Mangalore were analysed for heavy minerals consist of principally opaques, hornblende, epidote, garnet, sillimanite, hypersthene and zircon, with minor amounts...

  13. Minimizing the scattering of a nonmagnetic cloak

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    Nonmagnetic cloak offers a feasible way to achieve invisibility at optical frequencies using materials with only electric responses. In this letter, we suggest an approximation of the ideal nonmagnetic cloak and quantitatively study its electromagnetic characteristics using a full-wave scattering...

  14. Rigorous analysis of non-magnetic cloaks

    DEFF Research Database (Denmark)

    Zhang, Jingjing; Luo, Yu; Mortensen, Asger

    2010-01-01

    Nonmagnetic cloak offers a feasible way to achieve invisibility at optical frequencies using materials with only electric responses. In this letter, we suggest an approximation of the ideal nonmagnetic cloak and quantitatively study its electromagnetic characteristics using a full-wave scattering...... to the surrounding material at the outer boundary. Our analysis also provides the flexibility of reducing the scattering in an arbitrary direction....

  15. Magnetic assembly of nonmagnetic particles into photonic crystal structures.

    Science.gov (United States)

    He, Le; Hu, Yongxing; Kim, Hyoki; Ge, Jianping; Kwon, Sunghoon; Yin, Yadong

    2010-11-10

    We report the rapid formation of photonic crystal structures by assembly of uniform nonmagnetic colloidal particles in ferrofluids using external magnetic fields. Magnetic manipulation of nonmagnetic particles with size down to a few hundred nanometers, suitable building blocks for producing photonic crystals with band gaps located in the visible regime, has been difficult due to their weak magnetic dipole moment. Increasing the dipole moment of magnetic holes has been limited by the instability of ferrofluids toward aggregation at high concentration or under strong magnetic field. By taking advantage of the superior stability of highly surface-charged magnetite nanocrystal-based ferrofluids, in this paper we have been able to successfully assemble 185 nm nonmagnetic polymer beads into photonic crystal structures, from 1D chains to 3D assemblies as determined by the interplay of magnetic dipole force and packing force. In a strong magnetic field with large field gradient, 3D photonic crystals with high reflectance (83%) in the visible range can be rapidly produced within several minutes, making this general strategy promising for fast creation of large-area photonic crystals using nonmagnetic particles as building blocks.

  16. Long-term controls on continental-scale bedrock river terrace deposition from integrated clast and heavy mineral assemblage analysis: An example from the lower Orange River, Namibia

    Science.gov (United States)

    Nakashole, Albertina N.; Hodgson, David M.; Chapman, Robert J.; Morgan, Dan J.; Jacob, Roger J.

    2018-02-01

    Establishing relationships between the long-term landscape evolution of drainage basins and the fill of sedimentary basins benefits from analysis of bedrock river terrace deposits. These fragmented detrital archives help to constrain changes in river system character and provenance during sediment transfer from continents (source) to oceans (sink). Thick diamondiferous gravel terrace deposits along the lower Orange River, southern Namibia, provide a rare opportunity to investigate controls on the incision history of a continental-scale bedrock river. Clast assemblage and heavy mineral data from seven localities permit detailed characterisation of the lower Orange River gravel terrace deposits. Two distinct fining-upward gravel terrace deposits are recognised, primarily based on mapped stratigraphic relationships (cross-cutting relationships) and strath and terrace top elevations, and secondarily on the proportion of exotic clasts, referred to as Proto Orange River deposits and Meso Orange River deposits. The older early to middle Miocene Proto Orange River gravels are thick (up to 50 m) and characterised by a dominance of Karoo Supergroup shale and sandstone clasts, whereas the younger Plio-Pleistocene Meso Orange River gravels (6-23 m thick) are characterised by more banded iron formation clasts. Mapping of the downstepping terraces indicates that the Proto gravels were deposited by a higher sinuosity river, and are strongly discordant to the modern Orange River course, whereas the Meso deposits were deposited by a lower sinuosity river. The heavy minerals present in both units comprise magnetite, garnet, amphibole, epidote and ilmenite, with rare titanite and zircon grains. The concentration of amphibole-epidote in the heavy minerals fraction increases from the Proto to the Meso deposits. The decrease in incision depths, recorded by deposit thicknesses above strath terraces, and the differences in clast character (size and roundness) and type between the two

  17. Provenance of sands from the confluence of the Amazon and Madeira rivers based on detrital heavy minerals and luminescence of quartz and feldspar

    Science.gov (United States)

    do Nascimento, Daniel R.; Sawakuchi, André O.; Guedes, Carlos C. F.; Giannini, Paulo C. F.; Grohmann, Carlos H.; Ferreira, Manuela P.

    2015-03-01

    Source-to-sink systems are poorly known in tropical rivers. For the Amazonian rivers, the majority of the provenance studies remain focused on the suspended load, implying a poor understanding of the processes governing production and distribution of sands. In this study, we perform heavy mineral and optically stimulated luminescence (OSL) analysis to cover the entire spectrum (heavy and light minerals fraction) of 29 sand samples of the Lower Madeira river region (Amazon and Madeira rivers), of which the main goal was to find provenance indicators specific to these rivers. Despite the tropical humid climate, the sands of the Amazon and Lower Madeira rivers are rich in unstable heavy minerals as augite, hypersthene, green hornblende and andalusite. The Madeira river is highlighted by its higher content of andalusite, with source attributed to the Amazon Craton (medium-to-high grade metamorphic rocks), while the Amazon river, upstream of the Madeira river mouth, has a signature of augite and hypersthene, that suggests an Andean provenance (volcanic rocks). Sands from the Madeira river can be tracked in the Amazon river by the increasing concentration in andalusite. OSL analysis of the light minerals fraction was used as an index of feldspar concentration and sedimentary history of quartz grains. Lower feldspar concentration and quartz grains with longer sedimentary history (higher OSL sensitivity) also point to a major contribution of cratonic sources for the sands in the Madeira river. While the sands from the Lower Madeira would be mainly supplied by cratonic rocks, previous work recognised that suspended sediments (silt and clay) are derived from Andean rocks. Therefore, we interpret a decoupling between the sources of sand and mud (silt and clay) under transport in the Madeira river. Andean sands (rich in augite and hypersthene) would be trapped in the foreland zones of the Beni and Mamoré tributaries. In the Amazon river sands, the low OSL sensitivity of the

  18. Examination techniques for non-magnetic rings

    International Nuclear Information System (INIS)

    Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.

    1990-01-01

    Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement

  19. Khnifiss Beach's Black Sand: Provenance and Transport Pathways Investigation Using Heavy Minerals' Characterization

    Science.gov (United States)

    Adnani, M.; Elbelrhiti, H.; Ahmamou, M.; Masmoudi, L.

    2014-12-01

    Arid areas in south of Morocco suffer from silting problem causing destruction of villages infrastructure, roads, agriculture land and oasis heritage. Black sand on Khnifiss beach near Tarfaya city (S-W Morocco) is marked by enrichment of heavy minerals. This later is an important fraction that could help to assess the provenance and transport pathways of sediment. The sand's origin investigation could be useful to fight against erosion and silting problems from the source of supply, to this end, mineralogical analysis was carried out in Khnifiss beach's sand using Optic Microscope and Scanning Electronic Microscope with dispersive energy (SEM- EDS), in addition to physico-chemical analysis provided by Electronic Microprobe. The results revealed: (i) a high grade of oxides (Rutile, Ilmenite, Magnetite, Ulvöspinel) in samples, (ii) silicates (Quartz, Clinopyroxene, feldspar, Zircon), (iii) phosphate (apatite) and (iv) carbonate (calcite). The dominance of iron oxides justifies the black sand's colour. Then, the mineral composition supposes interference between different origins: proximal source (Calcareous cliff) for calcite, distal sources of oxides and silicates are supposed to be eroded and carried by Drâa valley from granite and igneous rocks in Anti-Atlasic field. Another source supposed might be a proximal volcanic island (Canaries island).

  20. Provenance of sediments from Sumatra, Indonesia - Insights from detrital U-Pb zircon geochronology, heavy mineral analyses and Raman spectroscopy

    Science.gov (United States)

    Liebermann, C.; Hall, R.; Gough, A.

    2017-12-01

    The island of Sumatra is situated at the southwestern margin of the Indonesian archipelago. Although it is the sixth largest island in the world, the geology of the Sumatra sedimentary basins and their underlying basement is relatively poorly understood in terms of their provenance. This work is a multi-proxy provenance study utilizing U-Pb detrital zircon dating by LA-ICP-MS combined with optical and Raman spectroscopy-based heavy mineral analysis. It will help to unravel the stratigraphy of Sumatra, contribute to paleogeographic reconstruction of western SE Asia, and aid a wider understanding of Sumatran petroleum plays. Thin section analyses, heavy mineral assemblages, and >3500 concordant U-Pb zircon ages, from samples acquired during two fieldwork seasons indicate a mixed provenance for Cenozoic sedimentary formations, including both local igneous sources and mature basement rocks. Characteristic Precambrian zircon age spectra are found in all analysed Cenozoic sedimentary strata. These can be correlated with zircon age populations found in Sumatran basement rocks; Neoproterozoic and Mesoproterozoic age groups are dominant (c. 500-600 Ma, c. 850-1000 Ma, c. 1050-1200 Ma). Paleoproterozoic to Archaean zircons occur as minor populations. The Phanerozoic age spectra of the Cenozoic formations are characterised by distinct Carboniferous, Permo-Triassic, and Jurassic-Cretaceous zircon populations. Permo-Triassic zircons are interpreted to come from granitoids in the Malay peninsula or Sumatra itself. Eocene to Lower Miocene strata are characterised by ultrastable heavy minerals such as zircon, tourmaline, and rutile, which together with garnet, suggest the principal sources were igneous and metamorphic basement rocks. Cenozoic zircons appear only from the Middle Miocene onwards. This change is interpreted to indicate a new contribution from a local volcanic arc, and is supported by the occurrence of unstable heavy minerals such as apatite and clinopyroxene, and the

  1. SEAFLOOR SEDIMENT CHARACTERISTICS AND HEAVY MINERAL OCCURENCES AT BETUMPAK CAPE AND ADJACENT AREA, BANGKA STRAIT, BANGKA BELITUNG PROVINCE

    Directory of Open Access Journals (Sweden)

    Rohendi Rohendi

    2017-07-01

    Full Text Available Thirty seafloor of sediment samples have been taken by using gravity corer and grab sampler at Betumpak Cape, and adjacent area of Bangka Belitung. The result of grain size analyses show that there are four sediment units: gravelly sand, gravelly muddy sand, silt and silty sand. Identification of Scanning Electron Microscope (SEM image on several samples shows the presence of clay mineral such as smectite, alunite, chlorite etc., may resulted from plagioclase weathering of granite. Based on heavy mineral analyses, its highest content is found at MTK-27 (northwest of Betumpak Cape. High content of apatite (0.94% wt and 1.07% wt is found on coarse sand fractions (115-170 mesh at MTK-29 (northeast Ular Cape and MTK-30 (north of Ular Cape. Generally, the heavy mineral accumulation is occurred on medium sand fraction (60-80 mesh as magnetite (7.86% wt, ilmenite (4.9% wt and zircon (1.32% wt. Based on these data, it shows that heavy mineral is accumulated on medium to coarse sand.

  2. Investor's and procurement guide South Africa. Pt. 1. Heavy minerals, rare earth elements, antimony

    International Nuclear Information System (INIS)

    Graupner, Torsten; Schwarz-Schampera, Ulrich; Hammond, Napoleon Q.; Opperman, Rehan; Long'a Tongu, Elisa; Kenan, Abdul O.; Nondula, Unathi; Tsanwani, Matamba

    2014-01-01

    This is the first part of the ''Investor's and Procurement Guide South Africa'', a handbook for investing and doing business in South Africa's mineral industry. It is anticipated that this publication will aid potential investors into considering South Africa as an investment destination, not only for raw materials, but also for related industries. This manual supplements the many publications available on the economic geology and mineral wealth in South Africa and has been designed to guide prospective and current investors, suppliers and mine equipment exporters through the process of doing business in Africa's biggest and dynamic economy. As well as detailing the mineral raw materials heavy minerals, rare-earth metals and antimony, the handbook provides a general introduction to South Africa and its infrastructure, the economical, political and judicial frame of the South African mining industry and an overview of the economic geology. South Africa has a long and complex geological history which dates back in excess of 3.6 billion years. The country has a vast mineral wealth, undoubtedly due to the fact that a significant proportion of the Archaean and younger rocks have been preserved. The mining of the enormous Witwatersrand gold deposits, commencing in 1886, has led to the establishment of South Africa's well-developed infrastructure and to the sustained growth of an industrial and service sector in the country. With the world's largest resources of PGMs, gold, chromite, vanadium and manganese and significant resources of iron, coal and numerous other minerals and metals, the minerals industry will continue to play a pivotal role in the growth of South Africa's economy in the foreseeable future. South Africa is one of the top destinations in Africa for foreign direct investments. South African headquartered companies have been major investors into foreign direct investments on the African continent in the past decade. Investing in South African companies

  3. UXC55 Non-Magnetic Robot

    CERN Document Server

    Najjar, Tony

    2017-01-01

    As part of the collaboration between CMS and the Lebanese American University, we are looking into building a non-magnetic inspection rover capable of roaming around UXC55 and specifically under the detector. The robot should be specifically tailored and engineered to cope with the strong magnetic field in the cavern (300 G on average with peaks up to 1500 G) as well as other constraints such as flammability and geometry. Moreover, we are also taking part in the development of the instrumentation and wireless communication of the rover. The biggest challenge in setting up a non-magnetic rover lies in the actuation mechanism, in other words, getting it to move; motors are rotary actuators that rely on the concept of a rotor “trying to catch up” to a rotating magnetic field. We quickly realize the complication with using this popular technology; the strong field created by the CMS magnet greatly interferes with the motor, rendering it utterly stalled. Our approach, on the other hand, consists of using compl...

  4. Distinguishing fluvio-deltaic facies by bulk geochemistry and heavy minerals: an example from the Miocene of Denmark

    DEFF Research Database (Denmark)

    Olivarius, Mette; Rasmussen, Erik S.; Siersma, Volkert Dirk

    2011-01-01

    Interpretations of seismic profiles, gamma-ray logs and sediment descriptions were used to classify seven facies in Miocene fluvio-deltaic deposits ofDenmark. An impartial approach was adopted by not including analytical data in the facies definition. This approach allowed identification of signi......Interpretations of seismic profiles, gamma-ray logs and sediment descriptions were used to classify seven facies in Miocene fluvio-deltaic deposits ofDenmark. An impartial approach was adopted by not including analytical data in the facies definition. This approach allowed identification...... grain size of quartz and heavy minerals from the channel facies towards the delta shoreface facies and further along the coast to the spit shoreface facies is associated with an increase in sorting and textural maturity. This trend is related to longshore drift. Increasing heavy mineral grain size...... is found from the delta slope facies offshore to the delta toe and shelf facies. This trend is interpreted as a result of sorting by turbidity currents. The mixed origin of the transgressive lag facies is shown by the poorer sorting in this facies. By indicating the amount of alteration the sediments have...

  5. Geochemistry and provenance of some detrital heavy minerals of alluvial sediments from Neagra Şarului River, Eastern Carpathians, Romania

    Science.gov (United States)

    Ciortescu, Catalina; Iancu, Ovidiu Gabriel; Bulgariu, Dumitru; Popa, Ciprian

    2014-05-01

    The present work focuses on the analyses of a selection of heavy mineral assemblages sampled from the Neagra Şarului River's alluvia, in order to determine their provenance and distribution, using their geochemical and physical characteristics. The study focused on a mountain river of about 30 km long, located in the north-western part of the Eastern Carpathians, an important tributary of the Bistria River. The bedrocks in the river drainage basin are constituted mainly by igneous rocks from Călimani Volcanic Complex in the west, and secondarily by a small area of low to medium grade metamorphic rocks, part of Crystalline-Mesozoic Zone, in the east. In order to trace the source of each individual mineral species, we prepared our samples via field separation and subsequent laboratory sieving using 8 different size fractions. An electromagnetic separator (Frantz Isodynamic) was used to separate and classify each heavy minerals species, depending on their magnetic susceptibility. Thus prepared, more than 500 grains per samples (from the 0.5-1 mm size fraction) were mounted on thin sections and analyzed using a Cambridge Microscan M9 with EDS system. These analyses served for mineral identification and relative abundance determination. The classification of the minerals and the nature of their inclusions are derived from the major element compositions computed from SEM-EDX analysis. We also used a stereo microscope in order to determine complementary properties of the grains, such as: color, degree of roundness and degree of alteration. In order of abundance, the main heavy minerals are magnetite, hematite, pyroxene, pyrite, manganese oxides, garnet, apatite, titanium oxides (ilmenite, titanite and rutile/anatase), chlorite, olivine, epidote, biotite and rhodochrosite. A particularity of the studied area is the presence of an altered magnetite caused first by the hydrothermal alteration and strong weathering of the source rocks and second by the river's acid water

  6. Basinal analysis of the Ecca and Lowermost Beaufort Beds and associated coal, uranium and heavy mineral beach sand occurrences

    International Nuclear Information System (INIS)

    Ryan, P.J.; Whitfield, G.G.

    1979-01-01

    The regional sediment transport directions, major provenance areas and the controlling palaeotectonic and palaeogeographic frameworks of sedimentation have been reconstructed for the Great Karoo Basin during the Permian. Analyses of this magnitude can be useful in regional exploration programmes for coal, uranium and fossil heavy mineral beach sand deposits. The strong palaeogeographic control on coal deposition is demonstrated by the fact that some of the most important deposits accumulated in topographically low lying areas on the pre-Karoo surface. Such areas formed sheltered environments ideal for the growth and accumulation of organic material. Elsewhere relatively slow rates of subsidence of a broad, protected, low lying delta plain controlled the deposition of coal. North of the main Karoo Basin many of the coal deposits are confined to structurally controlled linear basins. Hundreds of sedimentary uranium occurrences of varying grade and size occur within a broad, discontinuous belt in the Lower Beaufort of the southwestern portion of the Karoo Basin. The uranium mineralization occurs in a variety of fluvial deposits usually rich in carbonaceous material. Minute tuffaceous fragments, reflecting contemporaneous vulcanism, form a minor but significant constituent in some of the uraniferous sandstones. The uranium occurrences are confined largely to the Southern and Western Facies of the Lower Beaufort, and occur mainly within the confines of the Karoo Trough. Consolidated heavy mineral beach deposits have been found in the predominantly fluvio-deltaic Middle Ecca Group of the Northern Facies at a number of widely separated locations. These deposits were formed by shore line processes, such as the reworking of delta-front sands, during periods of temporary marine regression

  7. Two-dimensional Monte Carlo simulations of structures of a suspension comprised of magnetic and nonmagnetic particles in uniform magnetic fields

    International Nuclear Information System (INIS)

    Peng Xiaoling; Min Yong; Ma Tianyu; Luo Wei; Yan Mi

    2009-01-01

    The structures of suspensions comprised of magnetic and nonmagnetic particles in magnetic fields are studied using two-dimensional Monte Carlo simulations. The magnetic interaction among magnetic particles, magnetic field strength, and concentrations of both magnetic and nonmagnetic particles are considered as key influencing factors in the present work. The results show that chain-like clusters of magnetic particles are formed along the field direction. The size of the clusters increases with increasing magnetic interaction between magnetic particles, while it keeps nearly unchanged as the field strength increases. As the concentration of magnetic particles increases, both the number and size of the clusters increase. Moreover, nonmagnetic particles are found to hinder the migration of magnetic ones. As the concentration of nonmagnetic particles increases, the hindrance on migration of magnetic particles is enhanced

  8. Heavy mineral as a tool to refine the stratigraphy of kaolin deposits in the Rio Capim Area, Northern Brazil

    Directory of Open Access Journals (Sweden)

    Ana M. Góes

    2007-09-01

    Full Text Available Studies of heavy minerals in kaolin deposits from the Ipixuna Formation in the Rio Capim area (Northern Brazil showed a mature to super mature assemblage dominated by zircon and tourmaline, and subordinately rutile, kyanite and staurolite. These minerals do not change much throughout the whole section; however, each kaolin unit displays a particular signature, defined by differences in the proportions of the whole assemblage of heavy minerals, as well as of their textural characteristics. This work revealed that the lower and upper kaolin units can be definitely considered as distinct depositional sequences. A higher proportion of opaque minerals and higher zircon values characterize the lower unit. The higher volumes of anhedric, rounded to sub-rounded grains of zircon and tourmaline in the upper unit suggests that this includes grains that were undergone to a higher degree of reworking. The increased volume of unaltered staurolite and kyanite in the upper unit leads to conclude that, even considering sediment reworking, a distinct source must be invoked. The results also show that the characteristics of the heavy mineral assemblage from the intermediate unit are comparable with those from the upper unit, which suggests they might record a same stratigraphic sequence.Estudos de minerais pesados provenientes em depósitos cauliníticos da Formação Ipixuna na região do rio Capim (Brasil revelaram uma mineralogia matura a supermatura, representada dominantemente por zircão e turmalina e, subordinadamente, rutilo, cianita e estaurolita. Os minerais encontrados não variam muito, entretanto cada unidade caulinítica apresenta uma assinatura particular definida por diferenças nasproporções entre os principais minerais, assim como em suas características texturais. Este trabalho demonstrou que asunidades de caulim soft (inferior e semi-flint (superior podem ser consideradas seqüências deposicionais distintas. As altas percentagens de opacos

  9. Electronic and magnetic properties of SnS2 monolayer doped with non-magnetic elements

    Science.gov (United States)

    Xiao, Wen-Zhi; Xiao, Gang; Rong, Qing-Yan; Wang, Ling-Ling

    2018-05-01

    We performed a systematic study of the electronic structures and magnetic properties of SnS2 monolayer doped with non-magnetic elements in groups IA, IIA and IIIA based on the first-principles methods. The doped systems exhibit half-metallic and metallic natures depending on the doping elements. The formation of magnetic moment is attributable to the cooperative effect of the Hund's rule coupling and hole concentration. The spin polarization can be stabilized and enhanced through confining the delocalized impurity states by biaxial tensile strain in hole-doped SnS2 monolayer. Both the double-exchange and p-p exchange mechanisms are simultaneously responsible for the ferromagnetic ground state in those hole-doped materials. Our results demonstrate that spin polarization can be induced and controlled in SnS2 monolayers by non-magnetic doping and tensile strain.

  10. New Insights into the Provenance of the Southern Junggar Basin in the Jurassic from Heavy Mineral Analysis and Sedimentary Characteristics

    Science.gov (United States)

    Zhou, T. Q.; Wu, C.; Zhu, W.

    2017-12-01

    Being a vital component of foreland basin of Central-western China, Southern Junggar Basin has observed solid evidences of oil and gas in recent years without a considerable advancement. The key reason behind this is the lack of systematic study on sedimentary provenance analysis of the Southern Junggar basin. Three parts of the Southern Junggar basin, including the western segment (Sikeshu Sag), the central segment (Qigu Fault-Fold Belt) and the eastern segment (Fukang Fault Zone), possess varied provenance systems, giving rise to difficulties for oil-gas exploration. In this study, 3468 heavy minerals data as well as the sedimentary environment analysis of 10 profiles and 7 boreholes were used to investigate the provenances of the deposits in the southern Junggar basin . Based on this research, it reveals that: Sikeshu sag initially shaped the foreland basin prototype in the Triassic and its provenance area of the sediments from the Sikeshu sag has primarily been situated in zhongguai uplift-chepaizi uplift depositional systems located in the northwestern margin of the Junggar Basin. From the early Jurassic, the key sources were likely to be late Carboniferous to early Permain post-collisional volcanic rocks from the North Tian Shan block to Centrao Tian Shan. In the Xishanyao formation, Abundant lithic metamorphic, epidote and garnet that suggests the source rocks were possibly late Carboniferous subduction-related arc volcanic rocks of the Central Tian Shan. In the Toutunhe formation, Bogda Mountains began uplifting and gradually becoming the major provenance. Moreover, the sedimentary boundaries of Junggar basin have also shifted towards the North Tian Shan again. In the late Jurassic, the conglomerates of the Kalazha formation directly overlie the fine-grained red beds of Qigu formation, which throw light on the rapid tectonic uplift of the North Tian Shan. In the eastern segment, meandering river delta and shore-lacustrine environments were fully developed

  11. The influence of heavy mineral crushing in analysis of U mobile

    International Nuclear Information System (INIS)

    Tatang-Suherman

    2000-01-01

    The aim of experiments is to find out the influence of sample crushing in analysis of U mobile it was compared between U content of crusher and uncrushed samples. The uncrushed samples including the grain size of minus 40, 60, 80 and 100 mesh, since while the uncrushed sample was minus 60, 80, 100, 120 and 150 mesh. The U analysis was done by comparing with fluorescence of standard sample using Fluorimetric determination. The result of uncrushed samples have a same concentration in all of grain fractions and the crushed samples have a higher concentration on the smallest of grain fractions. The content of U mobile from crushed sample have significant result at - 120 mesh to - 150 mesh

  12. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

    2013-01-01

    Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

  13. The impact on environment and population of the sands with radioactive heavy minerals processing activity

    International Nuclear Information System (INIS)

    Aurelian, F.; Popescu, M.; Georgescu, D.

    2006-01-01

    The paper presents a case study concerning the impact on environment and population of a Pilot Station, which was used between 1970 and 1996 to obtain mono-mineral concentrates (ilmenite, zircon, garnet, rutile, monazite) by processing alluvial and seashore sands. The processing technological flow sheet was constituted only of physical separation processes, where were operating equipments such as shaking tables, electric and magnetic separators, attrition equipments, etc. The paper is structured on three levels and presents: - A brief description of the Pilot Station activity, sand types processed and its physical, chemical and mineralogic characteristics. The obtained products were: garnets with 10 ppm uranium and 60 ppm thorium, ilmenite with 10 ppm uranium and 20 ppm thorium, zircon with 450 ppm uranium and 750 ppm thorium and monazite with 3,000 ppm uranium and 20,000 ppm thorium. The sterile accumulated during the Pilot Station functioning time is also characterized. - The impact of the Pilot Station activity on environment (soil, air). The contamination sources are identified and characterized. The only one contamination pathway is represented by 'radioactive dust' resulted from the sands processing activity. The contamination processes are explained and justified. The contaminated soil surface was investigated through: gamma rate doses determination (at the surface and on a depth o f up to 40 cm), measurement of Rn 222 + Rn 220 concentration at one meter distance from the surface and for 40 cm soil depth, analysis of uranium, radium and thorium for samples collected from a soil depth ranging between 10 and 40 cm. There were elaborated maps showing gamma rate doses distribution and the specific activity for the surface as well as for the different soil depths. It was established the contamination level and its value was compared to the ones stipulated by Romanian Nuclear Authority norms, namely 0.2 Bq/g for the specific activity (Ra 226 + Th 232) and 0.3

  14. Pre- and post-monsoonal changes in grain size and heavy minerals in the sediments from Kalbadevi Bay, Ratnagiri, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Fernandes, D.

    to the monsoonal effects, where higher sand is derived from the shallow depths due to the wave action. It appears that the sand deposited during the monsoon period does not get compacted and therefore removed during transition period, thereby resulting... particles of magnetite are removed from the Bay after the monsoon due to current action and deposited to the deeper part of the shelf. The offshore non-magnetite heavy minerals in Kalbadevi Bay are predominantly ilmenite. The distribution...

  15. Effects of nonmagnetic interparticle forces on magnetorheological fluids

    International Nuclear Information System (INIS)

    Klingenberg, D J; Olk, C H; Golden, M A; Ulicny, J C

    2010-01-01

    Effects of nonmagnetic interparticle forces on the on- and off-state behavior of magnetorheological fluids are investigated experimentally and with particle-level simulations. Suspensions of iron particles in an aliphatic oil are modified by surface-active species. The modifications significantly alter the off-state properties, but have little impact on the field-induced stresses. Simulations show similar behavior. Off-state rheological properties are strongly influenced by van der Waals forces and modifications of the short-range repulsive forces. Field-induced stresses are less sensitive to the nonmagnetic forces.

  16. Effects of nonmagnetic interparticle forces on magnetorheological fluids

    International Nuclear Information System (INIS)

    Klingenberg, D J; Olk, C K; Golden, M A; Ulicny, J C

    2009-01-01

    Effects of nonmagnetic interparticle forces on the on- and off-state behavior of MR fluids are investigated experimentally and with particle-level simulations. Suspensions of iron particles in an aliphatic oil are modified by surface-active species. The modifications significantly alter the off-state properties, but have little impact on the field-induced stresses. Simulations show similar behavior. Off-state rheological properties are strongly influenced by van der Waals forces and modifications of the short-range repulsive forces. Field-induced stresses are less sensitive to the nonmagnetic forces.

  17. Heavy mineral placers

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.

    range from about -20 0 c to +50 0 c when rock is subject totemperature changes, all parts of the rock do not expand and contract at equal rates and therefore repetitive stresses of various intensities are set up which cause rock to break.... This process is effective in barren and desert areas, where temperatures are more than 40 0 C during day time. Mechanical action of organisms Both directly and indirectly plants and animals accomplish considerable work of rock disintegration. Tree trunks...

  18. Investor's and procurement guide South Africa. Pt. 1. Heavy minerals, rare earth elements, antimony

    Energy Technology Data Exchange (ETDEWEB)

    Graupner, Torsten; Schwarz-Schampera, Ulrich [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Berlin (Germany); Hammond, Napoleon Q.; Opperman, Rehan; Long' a Tongu, Elisa; Kenan, Abdul O.; Nondula, Unathi; Tsanwani, Matamba [Council for Geoscience (CGS), Pretoria (South Africa). Dept. of Mineral Resources Development; Liedke, Maren; Marbler, Herwig [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Berlin (Germany). Deutsche Rohstoffagentur (DERA)

    2014-03-15

    This is the first part of the ''Investor's and Procurement Guide South Africa'', a handbook for investing and doing business in South Africa's mineral industry. It is anticipated that this publication will aid potential investors into considering South Africa as an investment destination, not only for raw materials, but also for related industries. This manual supplements the many publications available on the economic geology and mineral wealth in South Africa and has been designed to guide prospective and current investors, suppliers and mine equipment exporters through the process of doing business in Africa's biggest and dynamic economy. As well as detailing the mineral raw materials heavy minerals, rare-earth metals and antimony, the handbook provides a general introduction to South Africa and its infrastructure, the economical, political and judicial frame of the South African mining industry and an overview of the economic geology. South Africa has a long and complex geological history which dates back in excess of 3.6 billion years. The country has a vast mineral wealth, undoubtedly due to the fact that a significant proportion of the Archaean and younger rocks have been preserved. The mining of the enormous Witwatersrand gold deposits, commencing in 1886, has led to the establishment of South Africa's well-developed infrastructure and to the sustained growth of an industrial and service sector in the country. With the world's largest resources of PGMs, gold, chromite, vanadium and manganese and significant resources of iron, coal and numerous other minerals and metals, the minerals industry will continue to play a pivotal role in the growth of South Africa's economy in the foreseeable future. South Africa is one of the top destinations in Africa for foreign direct investments. South African headquartered companies have been major investors into foreign direct investments on the African continent in the past

  19. Numerical analysis of microstructure formation of magnetic particles and nonmagnetic particles in MR fluids

    International Nuclear Information System (INIS)

    Ido, Y; Yamaguchi, T; Inagaki, T

    2009-01-01

    Microstructure formation of magnetic particles and nonmagnetic particles in MR fluids is investigated using the particle method simulation. Nonmagnetic sphere particles are rearranged in the field direction due to the chain-like cluster formation of magnetic particles. In the contrast, the nonmagnetic spherocylinder particles are not sufficiently rearranged in the field direction by using the cluster formation of sphere magnetic particles.

  20. Nonmagnetic impurity in the spin-gap state

    International Nuclear Information System (INIS)

    Nagaosa, N.; Ng, T.

    1995-01-01

    The effects of nonmagnetic strong scatterers (unitary limit) on magnetic and transport properties are studied for resonating-valence-bond states in both the slave-boson and slave-fermion mean-field theories with the gap for the triplet excitations. In the d-wave pairing state of the slave-boson mean-field theory in two dimensions, there is no true gap for spinons, but the Anderson localization occurs, which leads to the local moment when the repulsive interaction is taken into account. In the slave-fermion mean-field theory, local moments are found bound to nonmagnetic impurities as a result of (staggered) gauge interaction. However, in both theories, localization of spinon does not appear in the resistivity, which shows the classical value for the holon

  1. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions.

    Science.gov (United States)

    Zhang, Kun; Li, Huan-Huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-Tao; Tian, Yu-Feng; Yan, Shi-Shen; Lin, Zhao-Jun; Kang, Shi-Shou; Chen, Yan-Xue; Liu, Guo-Lei; Mei, Liang-Mo

    2015-09-21

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current voltage, and this rectification voltage strongly varies with the external magnetic field. We find that the rectification magnetoresistance in Al/Ge Schottky heterojunctions is as large as 250% at room temperature, which is greatly enhanced as compared with the conventional magnetoresistance of 70%. The findings of rectification magnetoresistance open the way to the new nonmagnetic Ge-based spintronics devices of large rectification magnetoresistance at ambient temperature under the alternating-current due to the simultaneous implementation of the rectification and magnetoresistance in the same devices.

  2. Influence of disorder on superconductivity in non-magnetic rare ...

    Indian Academy of Sciences (India)

    Influence of disorder on superconductivity in non-magnetic rare-earth nickel borocarbides. G FUCHS1,∗. , K-H M ¨ULLER1, J FREUDENBERGER1, K NENKOV1,. S-L DRECHSLER1, S V SHULGA1, D LIPP2, A GLADUN2,. T CICHOREK3 and P GEGENWART3. 1Institut für Festkörper- und Werkstofforschung, D-01171 ...

  3. Large rectification magnetoresistance in nonmagnetic Al/Ge/Al heterojunctions

    OpenAIRE

    Zhang, Kun; Li, Huan-huan; Grünberg, Peter; Li, Qiang; Ye, Sheng-tao; Tian, Yu-feng; Yan, Shi-shen; Lin, Zhao-jun; Kang, Shi-shou; Chen, Yan-xue; Liu, Guo-lei; Mei, and Liang-mo

    2015-01-01

    Magnetoresistance and rectification are two fundamental physical properties of heterojunctions and respectively have wide applications in spintronics devices. Being different from the well known various magnetoresistance effects, here we report a brand new large magnetoresistance that can be regarded as rectification magnetoresistance: the application of a pure small sinusoidal alternating-current to the nonmagnetic Al/Ge Schottky heterojunctions can generate a significant direct-current volt...

  4. Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; Bailey, Elizabeth A.; Schmidt, Jeanine M.; Shew, Nora B.; Gamble, Bruce M.; Labay, Keith A.

    2011-01-01

    The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, environmental impact assessments, and studies in medical geology. This Microsoft Access database serves as a data archive in support of present and future Alaskan geologic and geochemical projects, and contains data tables describing historical and new quantitative and qualitative geochemical analyses. The analytical results were determined by 85 laboratory and field analytical methods on 264,095 rock, sediment, soil, mineral and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed in USGS laboratories or, under contracts, in commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects from 1962 to 2009. In addition, mineralogical data from 18,138 nonmagnetic heavy mineral concentrate samples are included in this database. The AGDB includes historical geochemical data originally archived in the USGS Rock Analysis Storage System (RASS) database, used from the mid-1960s through the late 1980s and the USGS PLUTO database used from the mid-1970s through the mid-1990s. All of these data are currently maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB were used to generate most of the AGDB data set. These data were checked for accuracy regarding sample location, sample media type, and analytical methods used. This arduous process of reviewing, verifying and, where necessary, editing all USGS geochemical data resulted in a significantly improved Alaska geochemical dataset. USGS data that were not previously in the NGDB because the data predate the earliest USGS geochemical databases, or were once excluded for programmatic reasons

  5. Attaining provenance proxies from OSL and TL sensitivities: Coupling with grain size and heavy minerals data from southern Brazilian coastal sediments

    International Nuclear Information System (INIS)

    Zular, André; Sawakuchi, André O.; Guedes, Carlos C.F.; Giannini, Paulo C.F.

    2015-01-01

    In the São Francisco do Sul (SFS) barrier in southern Brazil, the optically stimulated luminescence (OSL) and thermoluminescence (TL) sensitivities of coastal sands vary according to geomorphological units. Sands from older beach ridges (ages older than 2000 years ago) show higher OSL and TL sensitivities than younger units (ages younger than 2000 years). Geomorphological units in the SFS attest to changes in provenance as a result of a coastal climate shift evidenced through grain size and heavy mineral analysis. We argue that in the SFS barrier sands, OSL and TL sensitivity signals provide an additional proxy to climate events and can be used as an alternative method to assess changes in provenance and tracking source-to-sink systems to monitor past and future environmental changes. - Highlights: • OSL and TL sensitivities are confronted with grain size and heavy minerals data. • We report OSL and 110 °C TL sensitivities as provenance proxies. • 110 °C TL sensitivity outlines environmental changes better than OSL sensitivity data.

  6. Size dependence of non-magnetic thickness in YIG nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Niyaifar, M., E-mail: md.niyaifar@gmail.com; Mohammadpour, H.; Dorafshani, M.; Hasanpour, A.

    2016-07-01

    This study is focused on particle size dependence of structural and magnetic properties in yttrium iron garnet (Y{sub 3}Fe{sub 5}O{sub 12}) nanoparticles. A series of YIG samples with different particle size were produced by varying the annealing temperatures. The X-ray analysis revealed an inverse correlation between lattice parameter and the crystallite size. The normal distribution is used for fitting the particles size distribution which is extracted from scanning electron micrographs. Also, by using the results of vibrating sample magnetometer, the magnetic diameter was calculated based on Langevin model in order to investigate the variation of dead layer thickness. Furthermore, the observed line broadening in Mössbauer spectra confirmed the increase of non-magnetic thickness due to the reduction of particle size. - Highlights: • Pure phase Y{sub 3}Fe{sub 5}O{sub 12} nanoparticles are fabricated in different particle size by a thermal treatment. • The size effect on magnetic properties is studied with a core/shell (magnetic/nonmagnetic) model. • The logarithmic variation of (dead layer thickness)/(particle size) ratio with the particle size is investigated. • The results of Mossbauer are explained based on the correlation between lattice constant and particle size variation.

  7. Computation of transient 3-D eddy current in nonmagnetic conductor

    International Nuclear Information System (INIS)

    Yeh, H.T.

    1978-01-01

    A numerical procedure was developed to solve transient three-dimensional (3-D) eddy current problems for nonmagnetic conductor. Integral equation formulation in terms of vector potential is used to simplify the matching of boundary conditions. The resulting equations and their numerical approximation were shown to be singular and to require special handling. Several types of symmetries were introduced. They not only reduce the number of algebraic equations to be solved, but also modify the nature of the equations and render them nonsingular. Temporal behavior was obtained with the Runge-Kutta method. The program is tested in several examples of eddy currents for its spatial and temporal profiles, shielding, boundary surface effects, and application of various symmetry options

  8. Magnetic field dependent atomic tunneling in non-magnetic glasses

    International Nuclear Information System (INIS)

    Ludwig, S.; Enss, C.; Hunklinger, S.

    2003-01-01

    The low-temperature properties of insulating glasses are governed by atomic tunneling systems (TSs). Recently, strong magnetic field effects in the dielectric susceptibility have been discovered in glasses at audio frequencies at very low temperatures. Moreover, it has been found that the amplitude of two-pulse polarization echoes generated in non-magnetic multi-component glasses at radio frequencies and at very low temperatures shows a surprising non-monotonic magnetic field dependence. The magnitude of the latter effect indicates that virtually all TSs are affected by the magnetic field, not only a small subset of systems. We have studied the variation of the magnetic field dependence of the echo amplitude as a function of the delay time between the two excitation pulses and at different frequencies. Our results indicate that the evolution of the phase of resonant TSs is changed by the magnetic field

  9. Magnetic field dependent atomic tunneling in non-magnetic glasses

    Science.gov (United States)

    Ludwig, S.; Enss, C.; Hunklinger, S.

    2003-05-01

    The low-temperature properties of insulating glasses are governed by atomic tunneling systems (TSs). Recently, strong magnetic field effects in the dielectric susceptibility have been discovered in glasses at audio frequencies at very low temperatures. Moreover, it has been found that the amplitude of two-pulse polarization echoes generated in non-magnetic multi-component glasses at radio frequencies and at very low temperatures shows a surprising non-monotonic magnetic field dependence. The magnitude of the latter effect indicates that virtually all TSs are affected by the magnetic field, not only a small subset of systems. We have studied the variation of the magnetic field dependence of the echo amplitude as a function of the delay time between the two excitation pulses and at different frequencies. Our results indicate that the evolution of the phase of resonant TSs is changed by the magnetic field.

  10. Interaction of the electromagnetic waves and non-magnetized plasmas

    International Nuclear Information System (INIS)

    Sun Aiping; Qiu Xiaoming; Dong Yuying; Li Liqiong

    2002-01-01

    The propagation of electromagnetic waves with 0.5 - 10 GHz in a non-magnetized collisional plasma slab is studied numerically. The change in the absorbed power, reflected power and transmitted power of the electromagnetic wave with collisional frequency of electrons and neutral atoms in plasma from 0.1 - 10 GHz, is calculated, in the condition of the uniform plasma with density of 10 10 or 10 11 cm -3 and depth of 10 cm, and the non-uniform plasma with density distribution of n = n 0 exp[2(z/d-1)] and depth of 10 cm, respectively. The results show that the absorbed power in either uniform or non-uniform plasma is large when the plasma density is large and collision frequency is high, and the peak value is 90%

  11. A modified Katsumata probe - ion sensitive probe for measurement in non-magnetized plasmas

    Czech Academy of Sciences Publication Activity Database

    Čada, Martin; Hubička, Zdeněk; Adámek, Petr; Olejníček, Jiří; Kment, Štěpán; Adámek, Jiří; Stöckel, Jan

    2015-01-01

    Roč. 86, č. 7 (2015), "073510-1"-"073510-7" ISSN 0034-6748 R&D Projects: GA MŠk LH12043 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : Katsumata probe * non-magnetized plasma * magnetron * ion temperature * non-magnetized plasmas Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.336, year: 2015

  12. Cenozoic exhumation and tectonic evolution of the Qimen Tagh Range, northern Tibetan Plateau: Insights from the heavy mineral compositions, detrital zircon U-Pb ages and seismic interpretations

    Science.gov (United States)

    Zhu, W.; Wu, C.; Wang, J.; Zhou, T.; Zhang, C.; Li, J.

    2017-12-01

    The Qaidam Basin is the largest intermountain basin within the Tibetan Plateau. The Cenozoic sedimentary flling characteristics of the basin was significantly influenced by the surrounding tectonic belt, such as the Altyn Tagh Range to the north-west and Qimen Tagh Range to the south. The tectonic evolution of the Qimen Tagh Range and the structural relationship between the Qaidam Basin and Qimen Tagh Range remain controversial. To address these issues, we analyzed thousands of heavy mineral data, 720 detrital zircon ages and seismic data of the Qaidam Basin. Based on the regional geological framework and our kinematic analyses, the Cenozoic tectonic evolution of the Qimen Tagh Range can be divided into two stages. From the Early Eocene to the Middle Miocene, the Devonian (400-360 Ma) and Permian to Triassic (300-200 Ma) zircons which were sourced from the Qimen Tagh Range and the heavy mineral assemblage of zircon-leucoxene-garnet-sphene on the north flank of the Qimen Tagh Range indicated that the Qimen Tagh Range has been exhumed before the Eocene and acted as the primary provenance of the Qaidam Basin. The Kunbei fault system (i.e. the Kunbei, Arlar and Hongliuquan faults) in the southwest of the Qaidam Basin, which can be seen as a natural study window of the Qimen Tagh Range, was characterized by left-lateral strike-slip faults and weak south-dipping thrust faults based on the seismic sections. This strike-slip motion was generated by the uplift of the Tibetan Plateau caused by the onset of the Indian-Eurasian collision. Since the Middle Miocene, the primary mineral assemblages along the northern flank of the Qimen Tagh Range changed from the zircon-leucoxene-garnet-sphene assemblage to the epidote-hornblende-garnet-leucoxene assemblage. Simultaneously, the Kunbei fault system underwent intense south-dipping thrusting, and a nearly 2.2-km uplift can be observed in the hanging wall of the Arlar fault. We attributed these variations to the rapid uplift event of

  13. Ferromagnetic clusters induced by a nonmagnetic random disorder in diluted magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bui, Dinh-Hoi [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Physics Department, Hue University’s College of Education, 34 Le Loi, Hue (Viet Nam); Phan, Van-Nham, E-mail: phanvannham@dtu.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam)

    2016-12-15

    In this work, we analyze the nonmagnetic random disorder leading to a formation of ferromagnetic clusters in diluted magnetic semiconductors. The nonmagnetic random disorder arises from randomness in the host lattice. Including the disorder to the Kondo lattice model with random distribution of magnetic dopants, the ferromagnetic–paramagnetic transition in the system is investigated in the framework of dynamical mean-field theory. At a certain low temperature one finds a fraction of ferromagnetic sites transiting to the paramagnetic state. Enlarging the nonmagnetic random disorder strength, the paramagnetic regimes expand resulting in the formation of the ferromagnetic clusters.

  14. Separation of magnetic from non-magnetic information in the Bitter pattern method

    International Nuclear Information System (INIS)

    Szmaja, Witold

    2001-01-01

    The paper deals with the problem of separating magnetic and non-magnetic contributions to the image contrast in the Bitter pattern method. With the help of the digital image difference procedure, it is demonstrated for the first time for the Bitter method that the separation is easy to achieve for relatively soft magnetic specimens, when an external field can be applied to simply produce the non-magnetic reference image of the specimen area under study. It is also shown that obtaining satisfactory results is principally impossible when removing the colloid from the specimen surface is used for the purpose of recording the non-magnetic image

  15. Large, Tunable Magnetoresistance in Nonmagnetic III-V Nanowires.

    Science.gov (United States)

    Li, Sichao; Luo, Wei; Gu, Jiangjiang; Cheng, Xiang; Ye, Peide D; Wu, Yanqing

    2015-12-09

    Magnetoresistance, the modulation of resistance by magnetic fields, has been adopted and continues to evolve in many device applications including hard-disk, memory, and sensors. Magnetoresistance in nonmagnetic semiconductors has recently raised much attention and shows great potential due to its large magnitude that is comparable or even larger than magnetic materials. However, most of the previous work focus on two terminal devices with large dimensions, typically of micrometer scales, which severely limit their performance potential and more importantly, scalability in commercial applications. Here, we investigate magnetoresistance in the impact ionization region in InGaAs nanowires with 20 nm diameter and 40 nm gate length. The deeply scaled dimensions of these nanowires enable high sensibility with less power consumption. Moreover, in these three terminal devices, the magnitude of magnetoresistance can be tuned by the transverse electric field controlled by gate voltage. Large magnetoresistance between 100% at room temperature and 2000% at 4.3 K can be achieved at 2.5 T. These nanoscale devices with large magnetoresistance offer excellent opportunity for future high-density large-scale magneto-electric devices using top-down fabrication approaches, which are compatible with commercial silicon platform.

  16. Label-Free Alignment of Nonmagnetic Particles in a Small Uniform Magnetic Field.

    Science.gov (United States)

    Wang, Zhaomeng; Wang, Ying; Wu, Rui Ge; Wang, Z P; Ramanujan, R V

    2018-01-01

    Label-free manipulation of biological entities can minimize damage, increase viability and improve efficiency of subsequent analysis. Understanding the mechanism of interaction between magnetic and nonmagnetic particles in an inverse ferrofluid can provide a mechanism of label-free manipulation of such entities in a uniform magnetic field. The magnetic force, induced by relative magnetic susceptibility difference between nonmagnetic particles and surrounding magnetic particles as well as particle-particle interaction were studied. Label-free alignment of nonmagnetic particles can be achieved by higher magnetic field strength (Ba), smaller particle spacing (R), larger particle size (rp1), and higher relative magnetic permeability difference between particle and the surrounding fluid (Rμr). Rμr can be used to predict the direction of the magnetic force between both magnetic and nonmagnetic particles. A sandwich structure, containing alternate layers of magnetic and nonmagnetic particle chains, was studied. This work can be used for manipulation of nonmagnetic particles in lab-on-a-chip applications.

  17. Accidental contamination during hydrocarbon exploitation and the rapid transfer of heavy-mineral fines through an overlying highly karstified aquifer (Paradiso Spring, SE Sicily)

    Science.gov (United States)

    Ruggieri, Rosario; Forti, Paolo; Antoci, Maria Lucia; De Waele, Jo

    2017-03-01

    The area around Ragusa in Sicily is well known for the exploration of petroleum deposits hosted in Mesozoic carbonate rocks. These reservoirs are overlain by less permeable rocks, whereas the surface geology is characterized by outcrops of Oligo-Miocene carbonate units hosting important aquifers. Some of the karst springs of the area are used as drinking water supplies, and therefore these vulnerable aquifers should be monitored and protected adequately. In the early afternoon (14:00) of 27 May until the late evening (19:30) of 28 May 2011, during the construction of an exploitation borehole (Tresauro 2), more than 1000 m3 of drilling fluids were lost in an unknown karst void. Two days later, from 06:30 on 30 May, water flowing from Paradiso Spring, lying some 13.7 km SW of the borehole and 378 m lower, normally used as a domestic water supply, was so intensely coloured that it was unfit for drinking. Bulk chemical analyses carried out on the water have shown a composition that is very similar to that of the drilling fluids lost at the Tresauro borehole, confirming a hydrological connection. Estimations indicate that the first signs of the drilling fluids took about 59 h to flow from their injection point to the spring, corresponding to a mean velocity of ∼230 m/h. That Paradiso Spring is recharged by a well-developed underground drainage system is also confirmed by the marked flow rate changes measured at the spring, ranging from a base flow of around 10-15 l/s to flood peaks of 2-3 m3/s. Reflecting the source and nature of the initial contamination, the pollution lasted for just a few days, and the water returned to acceptable drinking-water standards relatively quickly. However, pollution related to heavy-mineral fines continues to be registered during flooding of the spring, when the aqueducts are normally shut down because of the high turbidity values. This pollution event offers an instructive example of how hydrocarbon exploitation in intensely karstified

  18. Local destruction of superconductivity by non-magnetic impurities in mesoscopic iron-based superconductors.

    Science.gov (United States)

    Li, Jun; Ji, Min; Schwarz, Tobias; Ke, Xiaoxing; Van Tendeloo, Gustaaf; Yuan, Jie; Pereira, Paulo J; Huang, Ya; Zhang, Gufei; Feng, Hai-Luke; Yuan, Ya-Hua; Hatano, Takeshi; Kleiner, Reinhold; Koelle, Dieter; Chibotaru, Liviu F; Yamaura, Kazunari; Wang, Hua-Bing; Wu, Pei-Heng; Takayama-Muromachi, Eiji; Vanacken, Johan; Moshchalkov, Victor V

    2015-07-03

    The determination of the pairing symmetry is one of the most crucial issues for the iron-based superconductors, for which various scenarios are discussed controversially. Non-magnetic impurity substitution is one of the most promising approaches to address the issue, because the pair-breaking mechanism from the non-magnetic impurities should be different for various models. Previous substitution experiments demonstrated that the non-magnetic zinc can suppress the superconductivity of various iron-based superconductors. Here we demonstrate the local destruction of superconductivity by non-magnetic zinc impurities in Ba0.5K0.5Fe2As2 by exploring phase-slip phenomena in a mesoscopic structure with 119 × 102 nm(2) cross-section. The impurities suppress superconductivity in a three-dimensional 'Swiss cheese'-like pattern with in-plane and out-of-plane characteristic lengths slightly below ∼1.34 nm. This causes the superconducting order parameter to vary along abundant narrow channels with effective cross-section of a few square nanometres. The local destruction of superconductivity can be related to Cooper pair breaking by non-magnetic impurities.

  19. Simulation of magnetic hysteresis loops and magnetic Barkhausen noise of α-iron containing nonmagnetic particles

    International Nuclear Information System (INIS)

    Li, Yi; Li, Qiulin; Liu, Wei; Xu, Ben; Hu, Shenyang; Li, Yulan

    2015-01-01

    The magnetic hysteresis loops and Barkhausen noise of a single α-iron with nonmagnetic particles are simulated to investigate into the magnetic hardening due to Cu-rich precipitates in irradiated reactor pressure vessel (RPV) steels. Phase field method basing Landau-Lifshitz-Gilbert (LLG) equation is used for this simulation. The results show that the presence of the nonmagnetic particle could result in magnetic hardening by making the nucleation of reversed domains difficult. The coercive field is found to increase, while the intensity of Barkhausen noise voltage is decreased when the nonmagnetic particle is introduced. Simulations demonstrate the impact of nucleation field of reversed domains on the magnetization reversal behavior and the magnetic properties

  20. Optimized cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials

    International Nuclear Information System (INIS)

    Yu Zhenzhong; Feng Yijun; Xu Xiaofei; Zhao Junming; Jiang Tian

    2011-01-01

    We present optimized design of cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials. Through an optimization procedure based on genetic algorithm, simpler cloak structure and more realizable material parameters can be achieved with better cloak performance than that of an ideal non-magnetic cloak with a reduced set of parameters. We demonstrate that a cloak shell with only five layers of two normal materials can result in an average 20 dB reduction in the scattering width for all directions when covering the inner conducting cylinder with the cloak. The optimized design can substantially simplify the realization of the invisibility cloak, especially in the optical range.

  1. Magnetization Reversal Process of Single Crystal α-Fe Containing a Nonmagnetic Particle

    International Nuclear Information System (INIS)

    Li Yi; Xu Ben; Li Qiu-Lin; Liu Wei; Hu Shen-Yang; Li Yu-Lan

    2015-01-01

    The magnetization reversal process and hysteresis loops in a single crystal α-iron with nonmagnetic particles are simulated in this work based on the Landau—Lifshitz—Gilbert equation. The evolutions of the magnetic domain morphology are studied, and our analyses show that the magnetization reversal process is affected by the interaction between the moving domain wall and the existing nonmagnetic particles. This interaction strongly depends on the size of the particles, and it is found that particles with a particular size contribute the most to magnetic hardening. (paper)

  2. Comparison of non-magnetic and magnetic beads in bead-based assays

    NARCIS (Netherlands)

    Hansenová Maňásková, S.; van Belkum, A.; Endtz, H.P.; Bikker, F.J.; Veerman, E.C.I.; van Wamel, W.J.B.

    2016-01-01

    Multiplex bead-based flow cytometry is an attractive way for simultaneous, rapid and cost-effective analysis of multiple analytes in a single sample. Previously, we developed various bead-based assays using non-magnetic beads coated with Staphylococcus aureus and Streptococcus pneumoniae antigens

  3. Designing the coordinate transformation function for non-magnetic invisibility cloaking

    International Nuclear Information System (INIS)

    Xu Xiaofei; Feng Yijun; Zhao Lin; Jiang Tian; Lu Chunhua; Xu Zhongzi

    2008-01-01

    An optical invisibility cloak based on a transformation approach has recently been proposed by a reduced set of material properties due to their easier implementation in reality and little need for an inhomogeneous permeability distribution, but the drawback of undesired scattering caused by the impedance mismatching at the outer boundary is unavoidable in such a cloak. By properly designing the coordinate transformation function to ensure impedance matching at the outer surface, we show that the performance of a nonmagnetic cylindrical cloak could be improved with minimized scattering fields. Using either a single high order power function or an optimized piecewise continuous power function, a cylindrical non-magnetic cloak has been designed with nearly perfect cloaking performance, which is better than those generated with a linear or a quadratic function. Due to the monotonicity of the designed power functions, the resulting cloak has no restriction on the size of the cloaking shell, therefore is suitable for both thick and thin cloaking structures.

  4. VIE-FG-FFT for Analyzing EM Scattering from Inhomogeneous Nonmagnetic Dielectric Objects

    Directory of Open Access Journals (Sweden)

    Shu-Wen Chen

    2014-01-01

    Full Text Available A new realization of the volume integral equation (VIE in combination with the fast Fourier transform (FFT is established by fitting Green’s function (FG onto the nodes of a uniform Cartesian grid for analyzing EM scattering from inhomogeneous nonmagnetic dielectric objects. The accuracy of the proposed method is the same as that of the P-FFT and higher than that of the AIM and the IE-FFT especially when increasing the grid spacing size. Besides, the preprocessing time of the proposed method is obviously less than that of the P-FFT for inhomogeneous nonmagnetic dielectric objects. Numerical examples are provided to demonstrate the accuracy and efficiency of the proposed method.

  5. Spin-dependent tunneling transport into CrO2 nanorod devices with nonmagnetic contacts.

    Science.gov (United States)

    Song, Yipu; Schmitt, Andrew L; Jin, Song

    2008-08-01

    Single-crystal nanorods of half-metallic chromium dioxide (CrO2) were synthesized and structurally characterized. Spin-dependent electrical transport was investigated in individual CrO2 nanorod devices contacted with nonmagnetic metallic electrodes. Negative magnetoresistance (MR) was observed at low temperatures due to the spin-dependent direct tunneling through the contact barrier and the high spin polarization in the half-metallic nanorods. The magnitude of this negative magnetoresistance decreases with increasing bias voltage and temperature due to spin-independent inelastic hopping through the barrier, and a small positive magnetoresistance was found at room temperature. It is believed that the contact barrier and the surface state of the nanorods have great influence on the spin-dependent transport limiting the magnitude of MR effect in this first attempt at spin filter devices of CrO2 nanorods with nonmagnetic contacts.

  6. Development of high yield strength non-magnetic steels for the equipments of nuclear fusion research

    International Nuclear Information System (INIS)

    Matsuoka, Hidenori; Mukai, Tetsuya; Ohtani, Hiroo; Tsuruki, Takanori; Okada, Yasutaka

    1979-01-01

    Recently, activity of nuclear fusion research and so forth increase the demand of non-magnetic materials for various equipments and structures. For these usage, very low magnetic permeability as well as high strength are required under high magnetic field. Based on fundamental research, middle C-17% Cr-7% Ni-N non-magnetic steel has been developed. The developed steel shows more stable austenite phase and possesses higher yield strength and endurance limit of more than 10 kg/mm 2 , compared with 18% Cr-8% Ni austenitic steel. Also the developed steel has good ductility and toughness in spite of the high yield strength and shows better machinability than usual high Mn non- magnetic steels. The large forgings of this newly developed steel are manufactured in the works for the equipments of nuclear fusion research and confirmed good mechanical properties, high fatigue strength and low permeability. (author)

  7. Apparatus and method for continuous separation of magnetic particles from non-magnetic fluids

    Science.gov (United States)

    Oder, Robin R.; Jamison, Russell E.

    2010-02-09

    A magnetic separator vessel (1) for separating magnetic particles from non-magnetic fluid includes a separation chamber having an interior and exterior wall, a top and bottom portion; a magnet (3) having first and second poles (2) positioned adjacent to the exterior wall, wherein the first pole is substantially diametrically opposed to the second pole; a inlet port (5) is directed into the top portion of the separation chamber, wherein the inlet port (5) is positioned adjacent to one of the first and second poles (2), wherein the inlet port (5) is adapted to transfer a mixture into the separation chamber; an underflow port (6) in communication with the bottom portion, wherein the underflow port (6) is adapted to receive the magnetic particles; and an overflow port (9) in communication with the separation chamber, wherein the overflow port (9) is adapted to receive the non-magnetic fluid.

  8. ANALYSIS OF NONMAGNETIC METAL INDUCTION HEATING PROCESSES BY FLAT-TYPE CIRCULAR SOLENOIDAL FIELD

    Directory of Open Access Journals (Sweden)

    Yu. Batygin

    2016-12-01

    Full Text Available The article analyzes the electromagnetic processes in the system of induction heating with estimating the main characteristics of heating the non-magnetic sheet metal. The analytical expressions for numerical estimates of the induced current in terms of the phase of the excitation signal are presented. The dependence for the heating temperature of the considered circular sheet metal area for the time corresponding to the interval phase has been determined.

  9. Antiferroic electronic structure in the nonmagnetic superconducting state of the iron-based superconductors.

    Science.gov (United States)

    Shimojima, Takahiro; Malaeb, Walid; Nakamura, Asuka; Kondo, Takeshi; Kihou, Kunihiro; Lee, Chul-Ho; Iyo, Akira; Eisaki, Hiroshi; Ishida, Shigeyuki; Nakajima, Masamichi; Uchida, Shin-Ichi; Ohgushi, Kenya; Ishizaka, Kyoko; Shin, Shik

    2017-08-01

    A major problem in the field of high-transition temperature ( T c ) superconductivity is the identification of the electronic instabilities near superconductivity. It is known that the iron-based superconductors exhibit antiferromagnetic order, which competes with the superconductivity. However, in the nonmagnetic state, there are many aspects of the electronic instabilities that remain unclarified, as represented by the orbital instability and several in-plane anisotropic physical properties. We report a new aspect of the electronic state of the optimally doped iron-based superconductors by using high-energy resolution angle-resolved photoemission spectroscopy. We find spectral evidence for the folded electronic structure suggestive of an antiferroic electronic instability, coexisting with the superconductivity in the nonmagnetic state of Ba 1- x K x Fe 2 As 2 . We further establish a phase diagram showing that the antiferroic electronic structure persists in a large portion of the nonmagnetic phase covering the superconducting dome. These results motivate consideration of a key unknown electronic instability, which is necessary for the achievement of high- T c superconductivity in the iron-based superconductors.

  10. Valley and spin resonant tunneling current in ferromagnetic/nonmagnetic/ferromagnetic silicene junction

    Directory of Open Access Journals (Sweden)

    Yaser Hajati

    2016-02-01

    Full Text Available We study the transport properties in a ferromagnetic/nonmagnetic/ferromagnetic (FNF silicene junction in which an electrostatic gate potential, U, is attached to the nonmagnetic region. We show that the electrostatic gate potential U is a useful probe to control the band structure, quasi-bound states in the nonmagnetic barrier as well as the transport properties of the FNF silicene junction. In particular, by introducing the electrostatic gate potential, both the spin and valley conductances of the junction show an oscillatory behavior. The amplitude and frequency of such oscillations can be controlled by U. As an important result, we found that by increasing U, the second characteristic of the Klein tunneling is satisfied as a result of the quasiparticles chirality which can penetrate through a potential barrier. Moreover, it is found that for special values of U, the junction shows a gap in the spin and valley-resolve conductance and the amplitude of this gap is only controlled by the on-site potential difference, Δz. Our findings of high controllability of the spin and valley transport in such a FNF silicene junction may improve the performance of nano-electronics and spintronics devices.

  11. Magnetic vs. non-magnetic colloids - A comparative adsorption study to quantify the effect of dye-induced aggregation on the binding affinity of an organic dye.

    Science.gov (United States)

    Williams, Tyler A; Lee, Jenny; Diemler, Cory A; Subir, Mahamud

    2016-11-01

    Due to attractive magnetic forces, magnetic particles (MPs) can exhibit colloidal instability upon molecular adsorption. Thus, by comparing the dye adsorption isotherms of MPs and non-magnetic particles of the same size, shape and functional group it should be possible to characterize the influence of magnetic attraction on MP aggregation. For a range of particle densities, a comparative adsorption study of malachite green (MG(+)) onto magnetic and non-magnetic colloids was carried out using a combination of a separation technique coupled with UV-vis spectroscopy, optical microscopy, and polarization dependent second harmonic generation (SHG) spectroscopy. Significant MP aggregation occurs in aqueous solution due to MG(+) adsorption. This alters the adsorption isotherm and challenges the determination of the adsorption equilibrium constant, Kads. The dye-induced aggregation is directly related to the MG(+) concentration, [MG(+)]. A modified Langmuir equation, which incorporates loss of surface sites due to this aggregation, accurately describes the resulting adsorption isotherms. The Kads of 1.1 (±0.3)×10(7) and a loss of maximum MP surface capacity of 2.8 (±0.7)×10(3)M(-1) per [MG(+)] has been obtained. Additionally, SHG has been established as an effective tool to detect aggregation in nanoparticles. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Effects of magnetic and nonmagnetic impurities on the spin susceptibility of a noncentrosymmetrical superconductor: Application to CePt3Si

    Science.gov (United States)

    Yavari, H.; Mokhtari, M.; Tamaddonpour, M.

    2013-10-01

    The combined effect of nonmagnetic and magnetic impurities on the spin susceptibility of a noncentrosymmetrical superconductor by considering a Cooper pairing model with a two-component order parameter composed of spin-singlet and spin-triplet pairing components is investigated. For clean superconductor CePt3Si, the low-temperature dependence (T →0) of spin susceptibility is linear which suggests that the gap function has line nodes, consistent with our gap model. We will show that in the presence of magnetic impurities the susceptibility does not vanish even in the absence of spin orbit coupling and in the region where the energy gap still is finite, and in the low concentration of magnetic impurities the spin susceptibility at zero temperature is proportional to impurity concentration.

  13. [Radiographic findings in 4 cows with traumatic reticuloperitonitis caused by a nonmagnetic copper wire].

    Science.gov (United States)

    Braun, U; Gansohr, B; Flückiger, M

    2003-04-01

    The goal of this study was to describe the findings in four cows with non-magnetic reticular foreign bodies composed of copper. The cows were referred to our clinic because of reduced appetite and a marked decrease in milk production. Based on the clinical findings, a tentative diagnosis of traumatic reticuloperitonitis was made in all cows. The reticulum of all cows was then examined ultrasonographically and radiographically. In all cows, radiographs of the reticulum showed wire-shaped foreign bodies, ranging from 3 to 7 cm in length, which appeared to have penetrated the reticular wall. Two cows (No. 3, 4) had a magnet in the reticulum close to the foreign body but there was no direct contact between the two. A magnet was administered to cows No. 1 and 2, and radiography of the reticulum was performed for a second time the following day. The magnets were observed in the reticulum; however, they did not contact the foreign bodies. Because all the magnets were correctly placed in the reticulum yet, despite close proximity, did not contact the foreign bodies, the latter were thought to be non-magnetic. Cow No. 1 was slaughtered. Left flank laparoruminotomy was performed in the remaining three cows. In all cows, copper foreign bodies ranging in length from 3.0 to 7.0 cm, were found in the reticulum. They had penetrated the reticular wall and were not attached to magnets. The radiographic findings described in the present study are strongly indicative of a non-magnetic foreign body. Ruminotomy is the treatment of choice but slaughter may also be considered.

  14. Liquid metal MHD studies with non-magnetic and ferro-magnetic structural material

    Energy Technology Data Exchange (ETDEWEB)

    Patel, A., E-mail: anipatel2009@gmail.com [Institute of Plasma Research, Gandhinagar 382428, Gujarat (India); Bhattacharyay, R. [Institute of Plasma Research, Gandhinagar 382428, Gujarat (India); Swain, P.K.; Satyamurthy, P. [Bhabha Atomic Research Center, Mumbai 400085, Maharashtra (India); Sahu, S.; Rajendrakumar, E. [Institute of Plasma Research, Gandhinagar 382428, Gujarat (India); Ivanov, S.; Shishko, A.; Platacis, E.; Ziks, A. [Institute of Physics, University of Latvia, Salaspils 2169 (Latvia)

    2014-10-15

    Highlights: • Effect of structural material on liquid metal MHD phenomena is studied. • Two identical test sections, one made of SS316L (non-magnetic) and other made of SS430 (ferromagnetic) structural material, are considered. • Wall electric potential and liquid metal pressure drop are compared under various experimental conditions. • Experimental results suggest screening of external magnetic field for SS430 material below the saturation magnetic field. - Abstract: In most of the liquid metal MHD experiments reported in the literature to study liquid breeder blanket performance, SS316/SS304 grade steels are used as the structural material which is non-magnetic. On the other hand, the structural material for fusion blanket systems has been proposed to be ferritic martensitic grade steel (FMS) which is ferromagnetic in nature. In the recent experimental campaign, liquid metal MHD experiments have been carried out with two identical test sections: one made of SS316L (non-magnetic) and another with SS430 (ferromagnetic), to compare the effect of structural materials on MHD phenomena for various magnetic fields (up to 4 T). The maximum Hartmann number and interaction number are 1047 and 300, respectively. Each test section consists of square channel (25 mm × 25 mm) cross-section with two U bends, with inlet and outlet at the middle portion of two horizontal legs, respectively. Pb–Li enters into the test section through a square duct and distributed into two parallel paths through a partition plate. In each parallel path, it travels ∼0.28 m length in plane perpendicular to the magnetic field and faces two 90° bends before coming out of the test section through a single square duct. The wall electrical potential and MHD pressure drop across the test sections are compared under identical experimental conditions. Similar MHD behavior is observed with both the test section at higher value of the magnetic field (>2 T)

  15. Specific heat jump at T/sub c/ of proximity effect sandwiches containing nonmagnetic localized states

    International Nuclear Information System (INIS)

    Maneeratankul, S.; Tang, I.M.

    1987-01-01

    The decrease in the transition temperature and the jump in the specific heat at T/sub c/ of proximity effect sandwiches containing nonmagnetic Anderson impurities in the normal layer are studied. The effects of the resonant scattering by the impurities are treated in the same manner as that used by Kaiser in his study of the effects of resonant scattering on the properties of bulk superconductors. Numerical calculations of the decrease in T/sub c/ and the jump in the specific heat at T/sub c/ as a function of the thickness of the normal layer are presented

  16. Detection and study of photo-generated spin currents in nonmagnetic semiconductor materials

    International Nuclear Information System (INIS)

    Miah, M. Idrish; Kityk, I.V.; Gray, E. MacA.

    2007-01-01

    The longitudinal current in Si-doped gallium arsenide was spin-polarized using circularly polarized light. The spin current was detected by the extraordinary Hall effect. An enhancement of Hall conductivity with increasing moderately Si-doping was found, indicating that the introduction of dopants increases the electronic spin polarization. This finding may provide an opportunity for controlling and manipulating nonmagnetic semiconductors via electron spin for operating device applications. Band energy calculations using pseudopotentials confirm the influence of Si content and electron-phonon interaction on the behaviour of the spin current and hence on the spin-dependent Hall voltage

  17. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    OpenAIRE

    Liren Fan; Jiqing Song; Wenbo Bai; Shengping Wang; Ming Zeng; Xiaoming Li; Yang Zhou; Haifeng Li; Haiwei Lu

    2016-01-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shel...

  18. Detection and study of photo-generated spin currents in nonmagnetic semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M. Idrish [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)], E-mail: m.miah@griffith.edu.au; Kityk, I.V. [Institute of Physics, J. Dlugosz University Czestochowa, PL-42201 Czestochowa (Poland); Gray, E. MacA. [Nanoscale Science and Technology Centre, Griffith University, Nathan, Brisbane, QLD 4111 (Australia)

    2007-10-15

    The longitudinal current in Si-doped gallium arsenide was spin-polarized using circularly polarized light. The spin current was detected by the extraordinary Hall effect. An enhancement of Hall conductivity with increasing moderately Si-doping was found, indicating that the introduction of dopants increases the electronic spin polarization. This finding may provide an opportunity for controlling and manipulating nonmagnetic semiconductors via electron spin for operating device applications. Band energy calculations using pseudopotentials confirm the influence of Si content and electron-phonon interaction on the behaviour of the spin current and hence on the spin-dependent Hall voltage.

  19. Electrical detection of spin current and spin relaxation in nonmagnetic semiconductors

    International Nuclear Information System (INIS)

    Miah, M Idrish

    2008-01-01

    We report an electrical method for the detection of spin current and spin relaxation in nonmagnetic semiconductors. Optically polarized spins are dragged by an electric field in GaAs. We use the anomalous Hall effect for the detection of spin current and spin relaxation. It is found that the effect depends on the electric field and doping density as well as on temperature, but not on the excitation power. A calculation for the effect is performed using the measured spin polarization by a pump-probe experiment. The results are also discussed in comparison with a quantitative evaluation of the spin lifetimes of the photogenerated electrons under drift in GaAs

  20. Electrical detection of spin current and spin relaxation in nonmagnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M Idrish [Nanoscale Science and Technology Centre and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Brisbane, QLD 4111 (Australia); Department of Physics, University of Chittagong, Chittagong 4331 (Bangladesh)], E-mail: m.miah@griffith.edu.au

    2008-09-21

    We report an electrical method for the detection of spin current and spin relaxation in nonmagnetic semiconductors. Optically polarized spins are dragged by an electric field in GaAs. We use the anomalous Hall effect for the detection of spin current and spin relaxation. It is found that the effect depends on the electric field and doping density as well as on temperature, but not on the excitation power. A calculation for the effect is performed using the measured spin polarization by a pump-probe experiment. The results are also discussed in comparison with a quantitative evaluation of the spin lifetimes of the photogenerated electrons under drift in GaAs.

  1. Position feedback control of a nonmagnetic body levitated in magnetic fluid

    International Nuclear Information System (INIS)

    Lee, J H; Nam, Y J; Park, M K; Yamane, R

    2009-01-01

    This paper is concerned with the position feedback control of a magnetic fluid actuator which is characterized by the passive levitation of a nonmagnetic body immersed in a magnetic fluid under magnetic fields. First of all, the magnetic fluid actuator is designed based on the ferrohydrostatic relation. After manufacturing the actuator, its static and dynamic characteristics are investigated experimentally. With the aid of the dynamic governing relation obtained experimentally and the proportional-derivative controller, the position tracking control of the actuator is carried out both theoretically and experimentally. As a result, the applicability of the proposed magnetic fluid actuator to various engineering devices is verified.

  2. Induction heating of rotating nonmagnetic billet in magnetic field produced by high-parameter permanent magnets

    Directory of Open Access Journals (Sweden)

    Ivo Doležel

    2014-04-01

    Full Text Available An advanced way of induction heating of nonmagnetic billets is discussed and modeled. The billet rotates in a stationary magnetic field produced by unmoving high-parameter permanent magnets fixed on magnetic circuit of an appropriate shape. The mathematical model of the problem consisting of two coupled partial differential equations is solved numerically, in the monolithic formulation. Computations are carried out using our own code Agros2D based on a fully adaptive higher-order finite element method. The most important results are verified experimentally on our own laboratory device.

  3. Kramers non-magnetic superconductivity in LnNiAsO superconductors.

    Science.gov (United States)

    Li, Yuke; Luo, Yongkang; Li, Lin; Chen, Bin; Xu, Xiaofeng; Dai, Jianhui; Yang, Xiaojun; Zhang, Li; Cao, Guanghan; Xu, Zhu-an

    2014-10-22

    We investigated a series of nickel-based oxyarsenides LnNiAsO (Ln=La, Ce, Pr, Nd, Sm) compounds. CeNiAsO undergoes two successive anti-ferromagnetic transitions at TN1=9.3 K and TN2=7.3 K; SmNiAsO becomes an anti-ferromagnet below TN≃3.5 K; NdNiAsO keeps paramagnetic down to 2 K but orders anti-ferromagnetically below TN≃1.3 K. Superconductivity was observed only in Kramers non-magnetic LaNiAsO and PrNiAsO with Tc=2.7 K and 0.93 K, respectively. The superconductivity of PrNiAsO is further studied by upper critical field and specific heat measurements, which reveal that PrNiAsO is a weakly coupled Kramers non-magnetic superconductor. Our work confirms that the nickel-based oxyarsenide superconductors are substantially different in mechanism to iron-based ones, and are likely to be described by the conventional superconductivity theory.

  4. Muon spin relaxation and nonmagnetic Kondo state in PrInAg2

    International Nuclear Information System (INIS)

    MacLaughlin, D. E.; Heffner, R. H.; Nieuwenhuys, G. J.; Canfield, P. C.; Amato, A.; Baines, C.; Schenck, A.; Luke, G. M.; Fudamoto, Y.; Uemura, Y. J.

    2000-01-01

    Muon spin relaxation experiments have been carried out in the Kondo compound PrInAg 2 . The zero-field muon relaxation rate is found to be independent of temperature between 0.1 and 10 K, which rules out a magnetic origin (spin freezing or a conventional Kondo effect) for the previously observed specific-heat anomaly at ∼0.5 K. At low temperatures the muon relaxation can be quantitatively understood in terms of the muon's interaction with nuclear magnetism, including hyperfine enhancement of the 141 Pr nuclear moment at low temperatures. This argues against a Pr 3+ ground-state electronic magnetic moment, and is strong evidence for the doublet Γ 3 crystalline-electric-field-split ground state required for a nonmagnetic route to heavy-electron behavior. The data imply the existence of an exchange interaction between neighboring Pr 3+ ions of the order of 0.2 K in temperature units, which should be taken into account in a complete theory of a nonmagnetic Kondo effect in PrInAg 2 . (c) 2000 The American Physical Society

  5. SQUID magnetometer using sensitivity correction signal for non-magnetic metal contaminants detection

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, Toshifumi, E-mail: sakuta.k@usp.ac.jp; Ohashi, Masaharu; Sakuta, Ken

    2016-11-15

    Highlights: • A high-frequency excitation is necessary to detect nonmagnetic metals using SQUID. • It is possible to detect a high-frequency magnetic field using the open loop technique. • Open loop operation leads to a change in the conversion factor. • Conversion between voltage and magnetic field for open loop operation are examined. - Abstract: Measurement methods with SQUID can accurately detect small magnetic metal contaminants based on their magnetic remanence. But, a high-frequency excitation is necessary to detect nonmagnetic metals, on the base of contrasts in electric conductivity. In this work, an open loop technique is introduced to facilitate this. The SQUID is negative feedback controlled (flux locked loop (FLL) operation) for the low frequency range, which includes significant noise due to the movement of the magnetic body or the change of the ambient magnetic field composed of the geomagnetic field and technical signals, and it operates in an open loop configuration for the high frequency range. When using the open loop technique, negative feedback is not applied to the high frequency range. Consequently, the V–Φ characteristic changes due to various causes, which leads to variations in the conversion factor between the SQUID output voltage and the magnetic field. In this study, conversion techniques for the magnetic field for open loop operation of SQUID in the high frequency range are examined.

  6. Theoretical study of ferromagnetic resonance in exchange - coupled magnetic / nonmagnetic / magnetic multilayer structure

    International Nuclear Information System (INIS)

    Oezdogan, K.; Oezdemir, M.; Yalcin, O.; Aktas, B.

    2002-01-01

    The dispersion relation on ferromagnetic films was calculation by using torque equation of motion with a damping term. The total energy including zeeman, demagnetizing and anisotropy energy terms was used to get ferromagnetic resonance frequency for both uniform and higher order spin wave modes. In antiferromagnetic films, the torque equation of motion for each sub-lattice were written to derive an expression for the dispersion relation. The magnetic trilayer system under investigation consist of two ferromagnetic layers separated by a nonmagnetic layer. The dispersion relation of magnetic/nonmagnetic/magnetic three layers is calculated by using Landau-Lifshitz dynamic equation of motion for the magnetization with interlayer exchange energy. As for the exchange-coupled resonance of ferromagnetic resonance (FMR), the theoretical study has been calculated for both symmetrical and asymmetrical structures. In this systems, the exchange-coupling parameter A 12 between neighboring layers was used to get resonance fields as a function of the angle between the magnetization vectors of each magnetic layers

  7. SQUID magnetometer using sensitivity correction signal for non-magnetic metal contaminants detection

    International Nuclear Information System (INIS)

    Yagi, Toshifumi; Ohashi, Masaharu; Sakuta, Ken

    2016-01-01

    Highlights: • A high-frequency excitation is necessary to detect nonmagnetic metals using SQUID. • It is possible to detect a high-frequency magnetic field using the open loop technique. • Open loop operation leads to a change in the conversion factor. • Conversion between voltage and magnetic field for open loop operation are examined. - Abstract: Measurement methods with SQUID can accurately detect small magnetic metal contaminants based on their magnetic remanence. But, a high-frequency excitation is necessary to detect nonmagnetic metals, on the base of contrasts in electric conductivity. In this work, an open loop technique is introduced to facilitate this. The SQUID is negative feedback controlled (flux locked loop (FLL) operation) for the low frequency range, which includes significant noise due to the movement of the magnetic body or the change of the ambient magnetic field composed of the geomagnetic field and technical signals, and it operates in an open loop configuration for the high frequency range. When using the open loop technique, negative feedback is not applied to the high frequency range. Consequently, the V–Φ characteristic changes due to various causes, which leads to variations in the conversion factor between the SQUID output voltage and the magnetic field. In this study, conversion techniques for the magnetic field for open loop operation of SQUID in the high frequency range are examined.

  8. Magnetism at the Interface of Magnetic Oxide and Nonmagnetic Semiconductor Quantum Dots.

    Science.gov (United States)

    Saha, Avijit; Viswanatha, Ranjani

    2017-03-28

    Engineering interfaces specifically in quantum dot (QD) heterostructures provide several prospects for developing multifunctional building block materials. Precise control over internal structure by chemical synthesis offers a combination of different properties in QDs and allows us to study their fundamental properties, depending on their structure. Herein, we studied the interface of magnetic/nonmagnetic Fe 3 O 4 /CdS QD heterostructures. In this work, we demonstrate the decrease in the size of the magnetic core due to annealing at high temperature by the decrease in saturation magnetization and blocking temperature. Furthermore, surprisingly, in a prominently optically active and magnetically inactive material such as CdS, we observe the presence of substantial exchange bias in spite of the nonmagnetic nature of CdS QDs. The presence of exchange bias was proven by the increase in magnetic anisotropy as well as the presence of exchange bias field (H E ) during the field-cooled magnetic measurements. This exchange coupling was eventually traced to the in situ formation of a thin antiferromagnetic FeS layer at the interface. This is verified by the study of Fe local structure using X-ray absorption fine structure spectroscopy, demonstrating the importance of interface engineering in QDs.

  9. Excitonic pathway to photoinduced magnetism in colloidal nanocrystals with nonmagnetic dopants.

    Science.gov (United States)

    Pinchetti, Valerio; Di, Qiumei; Lorenzon, Monica; Camellini, Andrea; Fasoli, Mauro; Zavelani-Rossi, Margherita; Meinardi, Francesco; Zhang, Jiatao; Crooker, Scott A; Brovelli, Sergio

    2018-02-01

    Electronic doping of colloidal semiconductor nanostructures holds promise for future device concepts in optoelectronic and spin-based technologies. Ag + is an emerging electronic dopant in III-V and II-VI nanostructures, introducing intragap electronic states optically coupled to the host conduction band. With its full 4d shell Ag + is nonmagnetic, and the dopant-related luminescence is ascribed to decay of the conduction-band electron following transfer of the photoexcited hole to Ag + . This optical activation process and the associated modification of the electronic configuration of Ag + remain unclear. Here, we trace a comprehensive picture of the excitonic process in Ag-doped CdSe nanocrystals and demonstrate that, in contrast to expectations, capture of the photohole leads to conversion of Ag + to paramagnetic Ag 2+ . The process of exciton recombination is thus inextricably tied to photoinduced magnetism. Accordingly, we observe strong optically activated magnetism and diluted magnetic semiconductor behaviour, demonstrating that optically switchable magnetic nanomaterials can be obtained by exploiting excitonic processes involving nonmagnetic impurities.

  10. Invariance of the magnetic behavior and AMI in ferromagnetic biphase films with distinct non-magnetic metallic spacers

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.F. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Gamino, M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Andrade, A.M.H. de [Instituto de Física, Universidade Federal do Rio Grande de Sul, 91501-970 Porto Alegre, RS (Brazil); Vázquez, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Correa, M.A. [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Bohn, F., E-mail: felipebohn@fisica.ufrn.br [Departamento de Física, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil)

    2017-02-01

    We investigate the quasi-static magnetic, magnetotransport, and dynamic magnetic properties in ferromagnetic biphase films with distinct non-magnetic metallic spacer layers. We observe that the nature of the non-magnetic metallic spacer material does not have significant influence on the overall biphase magnetic behavior, and, consequently, on the magnetotransport and dynamic magnetic responses. We focus on the magnetoimpedance effect and verify that the films present asymmetric magnetoimpedance effect. Moreover, we explore the possibility of tuning the linear region of the magnetoimpedance curves around zero magnetic field by varying the probe current frequency in order to achieve higher sensitivity values. The invariance of the magnetic behavior and the asymmetric magnetoimpedance effect in ferromagnetic biphase films with distinct non-magnetic metallic spacers place them as promising candidates for probe element and open possibilities to the development of lower-cost high sensitivity linear magnetic field sensor devices.

  11. Corrosion behavior of beryllium copper and other nonmagnetic alloys in simulated drilling environments

    International Nuclear Information System (INIS)

    Cribb, W.R.; Booker, J.; Kane, R.D.; Turn, J.C.

    1984-01-01

    Beryllium copper (BeCu) alloys are known to exhibit high strength and good electrical conductivity. Other attractive properties, low magnetic susceptibility and resistance to galling, make these alloys strong contenders for use as drill collars and instrument housings in drilling equipment. Environmental cracking and corrosion tests were conducted in autoclaves at 66, 121 and 149 C (150, 250 and 300 F) in environments as severe as 10% H 2 S, 20% CO 2 balance N 2 . The results indicate Brush Alloy 25 adequately resists environmental cracking for these conditions, whereas certain nonmagnetic stainless steel cracked. Brush Alloy 25 exhibits acceptable corrosion rates at or below temperatures of 149 C (300 F) in environments with up to 1% H 2 S. Acceptable rates were also observed for environments containing up to 10% H 2 S at 66 C (150 F). The alloy showed this similar acceptable behavior in billet or tube form regardless of the aging treatment

  12. Theoretical study of optical conductivity of graphene with magnetic and nonmagnetic adatoms

    Science.gov (United States)

    Majidi, Muhammad Aziz; Siregar, Syahril; Rusydi, Andrivo

    2014-11-01

    We present a theoretical study of the optical conductivity of graphene with magnetic and nonmagnetic adatoms. First, by introducing an alternating potential in a pure graphene, we demonstrate a gap formation in the density of states and the corresponding optical conductivity. We highlight the distinction between such a gap formation and the so-called Pauli blocking effect. Next, we apply this idea to graphene with adatoms by introducing magnetic interactions between the carrier spins and the spins of the adatoms. Exploring various possible ground-state spin configurations of the adatoms, we find that the antiferromagnetic configuration yields the lowest total electronic energy and is the only configuration that forms a gap. Furthermore, we analyze four different circumstances leading to similar gaplike structures and propose a means to interpret the magneticity and the possible orderings of the adatoms on graphene solely from the optical conductivity data. We apply this analysis to the recently reported experimental data of oxygenated graphene.

  13. Reversible rectification of vortex motion in magnetic and non-magnetic asymmetric pinning potentials

    International Nuclear Information System (INIS)

    Gonzalez, E.M.; Gonzalez, M.P.; Nunez, N.O.; Villegas, J.E.; Anguita, J.V.; Jaafa, M.; Asenjo, A.; Vicent, J.L.

    2006-01-01

    Nb films have been grown on arrays of asymmetric pinning centers. The lattice vortex dynamics could be modified, almost at will, by periodic pinning potentials. In the case of asymmetric pinning potentials a vortex ratchet effect occurs: the vortex lattice motion is rectified. That is, an injected ac current yields an output dc voltage, which polarity could be tuned. The output signal polarity could be switched with the applied magnetic field and the ac current strength. Ratchet effect occurs when asymmetric potentials induce outward particles flow under external fluctuations in the lack of driven direct outward forces. The output signal is similar using magnetic or non-magnetic submicrometric array of pinning centers. This device works as an adiabatic rocking ratchet. This superconducting ratchet could be a model to study biological motors

  14. Magnetic levitation by induced eddy currents in non-magnetic conductors and conductivity measurements

    International Nuclear Information System (INIS)

    Iniguez, J; Raposo, V; Flores, A G; Zazo, M; Hernandez-Lopez, A

    2005-01-01

    We report a study on magnetic levitation by induced ac currents in non-magnetic conductors at low frequencies. Our discussion, based on Faraday's induction law, allows us to distinguish the two components of the current responsible for levitation and heating, respectively. The experimental evaluation of the levitation force in a copper ring revealed the accuracy of our analysis, clearly illustrating its asymptotic behaviour versus frequency, and validating it for the qualitative analysis of magnetic levitation and heating in conductors of different shapes such as tubes and discs, composed of collections of conductive loops. The analysis of the results allows precise values of its electrical conductivity to be found. With the help of a simulation technique, this work also reveals the progressive deformation undergone by magnetic induction lines due to magnetic screening when frequency increases

  15. Magnetic levitation by induced eddy currents in non-magnetic conductors and conductivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Iniguez, J; Raposo, V; Flores, A G; Zazo, M; Hernandez-Lopez, A [Departamento de Fisica Aplicada, Universidad de Salamanca, E-37071, Salamanca (Spain)

    2005-11-01

    We report a study on magnetic levitation by induced ac currents in non-magnetic conductors at low frequencies. Our discussion, based on Faraday's induction law, allows us to distinguish the two components of the current responsible for levitation and heating, respectively. The experimental evaluation of the levitation force in a copper ring revealed the accuracy of our analysis, clearly illustrating its asymptotic behaviour versus frequency, and validating it for the qualitative analysis of magnetic levitation and heating in conductors of different shapes such as tubes and discs, composed of collections of conductive loops. The analysis of the results allows precise values of its electrical conductivity to be found. With the help of a simulation technique, this work also reveals the progressive deformation undergone by magnetic induction lines due to magnetic screening when frequency increases.

  16. Thermopower in double planar tunnel junctions with ferromagnetic barriers and nonmagnetic electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wilczyński, M., E-mail: wilczyns@if.pw.edu.pl

    2017-01-01

    The Seebeck effect is investigated in double planar tunnel junctions consisting of nonmagnetic electrodes and the central layer separated by ferromagnetic barriers. Calculations are performed in the linear response theory using the free-electron model. The thermopower is analyzed as a function of the thickness of the central layer, temperature of the junctions and the relative orientation of magnetic moments of the barriers. It has been found that the thermopower can be significantly enhanced in the junction with special central layer thickness due to electron tunneling by resonant states. The thickness of the central layer for which the thermopower is enhanced depends not only on the temperature of the junction but also on the orientation of magnetic moments in the barriers. - Highlights: • Thermopower in the double planar junctions with magnetic barriers is analyzed. • Thermopower can be enhanced due to the resonant tunneling. • Thermopower depends on the magnetic configuration of the junction.

  17. The effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors

    International Nuclear Information System (INIS)

    Zhao Jun-Qing; Ding Meng; Zhang Tian-You; Zhang Ning-Yu; Pang Yan-Tao; Ji Yan-Ju; Chen Ying; Wang Feng-Xiang; Fu Gang

    2012-01-01

    We investigated the effect of spin-orbit coupling on magnetoresistance in nonmagnetic organic semiconductors. A Lorentz-type magnetoresistance is obtained from spin-orbit coupling-dependent spin precession under the condition of a space-charge-limited current. The magnetoresistance depends on the initial spin orientation of the electron with respect to the hole in electron—hole pairs, and the increasing spin-orbit coupling slows down the change in magnetoresistance with magnetic field. The field dependence, the sign and the saturation value of the magnetoresistance are composite effects of recombination and dissociation rate constants of singlet and triplet electron—hole pairs. The simulated magnetoresistance shows good consistency with the experimental results. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  18. Magnetically gated accretion in an accreting 'non-magnetic' white dwarf.

    Science.gov (United States)

    Scaringi, S; Maccarone, T J; D'Angelo, C; Knigge, C; Groot, P J

    2017-12-13

    White dwarfs are often found in binary systems with orbital periods ranging from tens of minutes to hours in which they can accrete gas from their companion stars. In about 15 per cent of these binaries, the magnetic field of the white dwarf is strong enough (at 10 6 gauss or more) to channel the accreted matter along field lines onto the magnetic poles. The remaining systems are referred to as 'non-magnetic', because until now there has been no evidence that they have a magnetic field that is strong enough to affect the accretion dynamics. Here we report an analysis of archival optical observations of the 'non-magnetic' accreting white dwarf in the binary system MV Lyrae, whose light curve displays quasi-periodic bursts of about 30 minutes duration roughly every 2 hours. The timescale and amplitude of these bursts indicate the presence of an unstable, magnetically regulated accretion mode, which in turn implies the existence of magnetically gated accretion, in which disk material builds up around the magnetospheric boundary (at the co-rotation radius) and then accretes onto the white dwarf, producing bursts powered by the release of gravitational potential energy. We infer a surface magnetic field strength for the white dwarf in MV Lyrae of between 2 × 10 4 gauss and 1 × 10 5 gauss, too low to be detectable by other current methods. Our discovery provides a new way of studying the strength and evolution of magnetic fields in accreting white dwarfs and extends the connections between accretion onto white dwarfs, young stellar objects and neutron stars, for which similar magnetically gated accretion cycles have been identified.

  19. Physical and mechanical properties of high manganese non-magnetic steel and its application to various products for commercial use

    International Nuclear Information System (INIS)

    Sasaki, Terufumi; Watanabe, Kenji; Nohara, Kiyohiko; Ono, Yutaka; Kondo, Nobuyuki; Sato, Shuzo.

    1982-01-01

    In order to develop new high manganese non-magnetic steels that can be employed to extensive applications ranging from cryogenic to elevated temperature uses, the effects of C and Mn on their magnetic permeability, thermal expansion coefficient and mechanical properties are investigated. It is found that the relation between thermal expansion coefficient, β, and both C and Mn contents can be expressed by the following linear regression equation: β( x 10 -6 / 0 C) = 17.66 + 3.82 C (%) - 0.22 Mn (%). Good mechanical properties are exhibited in the wide range of Mn contents between 18 % and 30 % at room temperature, while there is a tendency that this optimum range of Mn content is narrowed at cryogenic temperature. Then, H-shapes, round bars and deformed bars are manufactured at the workshops using 5t vacuum melted ingots, aiming to establish the conditions for practical processes for final products and to study such various characteristics of the products as their physical and mechanical properties, machinability and weldability. As a result, it is shown that all of those products have excellent properties as non-magnetic steels. In addition, the manufacturing of non-magnetic pinch rolls attached to the electro-magnetic stirring equipment on the continuous casting machine is described in detail as one of the practical applications of the high Mn non-magnetic steels. (author)

  20. Fabrication of a Textured Non-Magnetic Ni-12at.%V Alloy Substrate for Coated Conductors

    DEFF Research Database (Denmark)

    Gao, M. M.; Grivel, Jean-Claude; Suo, H. L.

    2011-01-01

    Ni-12at.%V alloy is a promising candidate for non-magnetic cube textured metallic substrates used for high temperature coated conductors. In this work, a textured Ni-12at.%V substrate has been fabricated by powder metallurgy route. After cold rolling and recrystallization annealing, a cube texture...

  1. Provenance Studies Through Petrography and Heavy Mineral

    African Journals Online (AJOL)

    USER

    are also cement and voids. These four parameters make up the bulk textural properties of any ..... tidal effect held sway.The field work ... Laterites.Geol.Surv. Nigeria Rept. No. 1027. nd. Folk, R. L. 1974.Petrology of Sedimentary Rocks (2.

  2. Measurement of the neutrino component of an antineutrino beam observed by a nonmagnetized detector

    International Nuclear Information System (INIS)

    Aguilar-Arevalo, A. A.; Anderson, C. E.; Fleming, B. T.; Linden, S. K.; Spitz, J.; Brice, S. J.; Brown, B. C.; Ford, R.; Garcia, F. G.; Kobilarcik, T.; Marsh, W.; Moore, C. D.; Polly, C. C.; Russell, A. D.; Stefanski, R. J.; Zeller, G. P.; Bugel, L.; Conrad, J. M.; Karagiorgi, G.; Nguyen, V.

    2011-01-01

    Two methods are employed to measure the neutrino flux of the antineutrino-mode beam observed by the MiniBooNE detector. The first method compares data to simulated event rates in a high-purity ν μ -induced charged-current single π + (CC1π + ) sample while the second exploits the difference between the angular distributions of muons created in ν μ and ν μ charged-current quasielastic (CCQE) interactions. The results from both analyses indicate the prediction of the neutrino flux component of the predominately antineutrino beam is overestimated--the CC1π + analysis indicates the predicted ν μ flux should be scaled by 0.76±0.11, while the CCQE angular fit yields 0.65±0.23. The energy spectrum of the flux prediction is checked by repeating the analyses in bins of reconstructed neutrino energy, and the results show that the spectral shape is well-modeled. These analyses are a demonstration of techniques for measuring the neutrino contamination of antineutrino beams observed by future nonmagnetized detectors.

  3. New magnetic materials obtained by ion-exchange reactions from non-magnetic layered perovskites

    International Nuclear Information System (INIS)

    Kageyama, H; Viciu, L; Caruntu, G; Ueda, Y; Wiley, J B

    2004-01-01

    New layered magnetic materials (MCl)Ca 2 Ta 3 O 10 (M = Cu, Fe), have been prepared by ion-exchange reactions of non-magnetic perovskite derivatives, ACa 2 Ta 3 O 10 (A = Rb, Li), in corresponding anhydrous molten salts. Powder x-ray diffraction patterns of the products are successfully indexed assuming tetragonal symmetry with cell dimensions a = 3.829 A and c = 15.533 A for Cu, and a = 3.822 A and c = 15.672 A for Fe. Being separated by the Ca 2 Ta 3 O 10 triple-layer perovskite slabs, the transition-metal chloride (MCl) network provides a two-dimensional magnetic lattice. Magnetic susceptibility measurements show that (CuCl)Ca 2 Ta 3 O 10 is in an antiferromagnetic state below 8 K, while (FeCl)Ca 2 Ta 3 O 10 has two anomalies at 91 and 125 K, suggesting successive phase transitions due to geometrical spin frustration

  4. Electromagnetic Screening and Skin-Current Distribution with Magnetic and Non-Magnetic Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Dahlberg, E [Dept. of Plasma Physics, Royal Institute of Technology, Stockholm (SE)

    1974-12-15

    In many applications it is permissible to assume that eddy currents are essentially confined to the skin of the conductor. However, the perfect-conductor approach, commonly employed for skin-current estimates, requires that also mud << L{sub t}, where mu is the relative permeability of the conductor, d its skin depth, and L{sub t} a characteristic length along its surface. The need for this restriction does not seem to be sufficiently well known. In this note simple formulae giving quantitative estimates - valid for arbitrary mud/L - for far-field skin-currents, eddy current losses and screening efficiency are derived for several simple configurations. Boundary conditions that should allow calculations for more complicated configurations are also presented. The parameter mud is important also for non-magnetic materials. Thus, the equivalence of a thin real screen (thickness D) and an infinitely thin screen with the same rhoomegaD will be improved if - in addition - mud is the same for both

  5. Induced magnetization spiral in a nonmagnetic metal sandwiched between two ferromagnets

    CERN Document Server

    Mathon, J; Villeret, M; Muniz, R B; Edwards, D M

    2000-01-01

    Calculation of the magnetic moment induced in a non-magnetic metal, sandwiched between two ferromagnets with magnetizations at an arbitrary angle, is reported. It is found that the induced magnetization rotates along a complex three-dimensional spiral and can undergo many complete 360 deg. rotations. A simple free-electron model is used to derive an analytic formula for the twist angle phi inside the spacer. This demonstrates that, contrary to the behavior of magnetization inside a domain wall in a ferromagnet, phi varies non-uniformly inside the spacer and exhibits plateaus of almost constant rotation separated by regions of sharp rotations by large angles. The calculation is extended to the case of a realistic Co/Cu/Co(0 0 1) trilayer described by s, p, d tight-binding bands fitted to an ab initio band structure. An analytic formula for the components of the induced moment (and hence, for phi) is derived using the stationary phase approximation. Its validity is tested against a fully numerical calculation u...

  6. Chelating capture and magnetic removal of non-magnetic heavy metal substances from soil

    Science.gov (United States)

    Fan, Liren; Song, Jiqing; Bai, Wenbo; Wang, Shengping; Zeng, Ming; Li, Xiaoming; Zhou, Yang; Li, Haifeng; Lu, Haiwei

    2016-02-01

    A soil remediation method based on magnetic beneficiation is reported. A new magnetic solid chelator powder, FS@IDA (core-shell Fe3O4@SiO2 nanoparticles coated with iminodiacetic acid chelators), was used as a reactive magnetic carrier to selectively capture non-magnetic heavy metals in soil by chelation and removal by magnetic separation. FS@IDA was prepared via inorganic-organic and organic synthesis reactions that generated chelating groups on the surface of magnetic, multi-core, core-shell Fe3O4@SiO2 (FS) nanoparticles. These reactions used a silane coupling agent and sodium chloroacetate. The results show that FS@IDA could chelate the heavy metal component of Cd, Zn, Pb, Cu and Ni carbonates, lead sulfate and lead chloride in water-insoluble salt systems. The resulting FS@IDA-Cd and FS@IDA-Pb chelates could be magnetically separated, resulting in removal rates of approximately 84.9% and 72.2% for Cd and Pb, respectively. FS@IDA could not remove the residual heavy metals and those bound to organic matter in the soil. FS@IDA did not significantly alter the chemical composition of the soil, and it allowed for fast chelating capture, simple magnetic separation and facilitated heavy metal elution. FS@IDA could also be easily prepared and reprocessed.

  7. Room temperature ferromagnetism in liquid-phase pulsed laser ablation synthesized nanoparticles of nonmagnetic oxides

    International Nuclear Information System (INIS)

    Singh, S. C.; Gopal, R.; Kotnala, R. K.

    2015-01-01

    Intrinsic Room Temperature Ferromagnetism (RTF) has been observed in undoped/uncapped zinc oxide and titanium dioxide spherical nanoparticles (NPs) obtained by a purely green approach of liquid phase pulsed laser ablation of corresponding metal targets in pure water. Saturation magnetization values observed for zinc oxide (average size, 9 ± 1.2 nm) and titanium dioxide (average size, 4.4 ± 0.3 nm) NPs are 62.37 and 42.17 memu/g, respectively, which are several orders of magnitude larger than those of previous reports. In contrast to the previous works, no postprocessing treatments or surface modification is required to induce ferromagnetism in the case of present communication. The most important result, related to the field of intrinsic ferromagnetism in nonmagnetic materials, is the observation of size dependent ferromagnetism. Degree of ferromagnetism in titanium dioxide increases with the increase in particle size, while it is reverse for zinc oxide. Surface and volume defects play significant roles for the origin of RTF in zinc oxide and titanium dioxide NPs, respectively. Single ionized oxygen and neutral zinc vacancies in zinc oxide and oxygen and neutral/ionized titanium vacancies in titanium dioxide are considered as predominant defect centres responsible for observed ferromagnetism. It is expected that origin of ferromagnetism is a consequence of exchange interactions between localized electron spin moments resulting from point defects

  8. AN INVESTIGATION ON SOFT MAGNETIC AND NON-MAGNETIC MATERIALS UNDER LOW FREQUENCY FOR BIOMEDICAL SENSOR APPLICATION

    Directory of Open Access Journals (Sweden)

    Sheroz Khan

    2012-02-01

    Full Text Available In consequence of the recent development of magnetic sensors in biomedical sector, the investigation of magneticmaterials has been a contributing factor in application stage. This paper proposes a novel technique to investigate materials by obtaining unique distinctive impedance peaks with unique impedance values. A magneto-inductive sensoris used to measure the induction of magnetic and non-magnetic impedance peaks related to the change in permeability, thus characterizing the materials under low frequency.

  9. INDUCTION HEATING OF NON-MAGNETIC SHEET METALS IN THE FIELD OF A FLAT CIRCULAR MULTITURN SOLENOID

    Directory of Open Access Journals (Sweden)

    Y. Batygin

    2016-06-01

    Full Text Available The theoretical analysis of electromagnetic processes in the system for induction heating presented by a flat circular multiturn solenoid positioned above a plane of thin sheet non-magnetic metal has been conducted. The calculated dependences for the current induced in a metal sheet blank and ratio of transformation determined have been obtained. The maximal value of the transformation ratio with regard to spreading the eddy-currents over the whole area of the sheet metal has been determined.

  10. Real-space distribution of the Hall current densities and their spin polarization in nonmagnetic zine-blende semiconductors

    Czech Academy of Sciences Publication Activity Database

    Středa, Pavel; Drchal, Václav

    2012-01-01

    Roč. 86, č. 19 (2012), "195204-1"-"195204-8" ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP204/11/1228 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z10100520 Keywords : nonmagnetic semiconductors * spin Hall currents Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.767, year: 2012

  11. Enhanced nuclear magnetic resonance in a non-magnetic cubic doublet

    International Nuclear Information System (INIS)

    Veenendaal, E.J.

    1982-01-01

    In this thesis two lanthanide compounds are studied which show enhanced nuclear magnetism at low temperatures: Rb 2 NaHoF 6 and CsNaHoF 6 . Chapter II gives a description of the 4 He-circulating refrigerator, which was built to provide the low temperatures required for the polarization of the enhanced nuclear moments. This type of dilution refrigerator was chosen because of its simple design and large cooling power. Chapter III is devoted to a comparison of the different types of dilution refrigerators. A theoretical discussion is given of their performance, starting from the differential equations, which govern the temperature distribution in the refrigerator. In chapter IV the actual performance of the refrigerator, described in chapter II is discussed. In chapter V a description of the NMR-apparatus, developed for very-low-temperature NMR experiments is given. In chapter VI experimental results on the compound Rb 2 NaHoF 6 are presented. The CEF-ground state of this compound is probably the non-magnetic doublet GAMMA 3 , but at a temperature of 170 K a structural phase transition lowers the crystal symmetry from cubic to tetragonal and the doublet is split into two singlets. In chapter VII specific heat, (enhanced) nuclear magnetic resonance and magnetization measurements on the compound Cs 2 NaHoF 6 are presented which also has a GAMMA 3 -doublet ground state. In zero magnetic field the degeneracy of the doublet is removed at a temperature of 393 mK, where a phase transition is induced by quadrupolar interactions. (Auth.)

  12. Review of the use of magnetic concentrates in geochemical exploration

    Science.gov (United States)

    Overstreet, W.C.; Day, G.W.

    1985-01-01

    Magnetic concentrates recovered readily by hand magnet from alluvial sediments or panned concentrates have been used successfully in exploration as a geochemical sample medium for Cu, Zn, Co, Cr, Mo, Ni, V, Sn, and Be, particularly in arid environments where alluvial sediments may be contaminated by aeolian debris. Opportunity for this use arose recently as chemical and spectrographic techniques were developed to determine the abundances of a variety of trace elements in Fe-rich media. The use of analytical data from magnetic concentrates was introduced as one of several anomaly-enhancement techniques based on heavy minerals and intended to identify blind ore deposits. An extensive literature, reviewed here, on the relation of the chemical composition of the mineral magnetite, a main component of magnetic concentrates, to geologic conditions of origin, facilitates the interpretation of trace-element data in the context of association with ore deposits.

  13. Radiographic findings in 4 cows with traumatic reticuloperitonitis due to a non-magnetic foreign body composed of copper

    International Nuclear Information System (INIS)

    Braun, U.; Gansohr, B.; Flückiger, M.

    2003-01-01

    The goal of this study was to describe the findings in four cows with non-magnetic reticular foreign bodies composed of copper. The cows were referred to our clinic because of reduced appetite and a marked decrease in milk production. Based on the clinical findings, a tentative diagnosis of traumatic reticuloperitonitis was made in all cows. The reticulum of all cows was then examined ultrasonographically and radiographically. In all cows, radiographs of the reticulum showed wire-shaped foreign bodies, ranging from 3 to 7 cm in length, which appeared to have penetrated the reticular wall. Two cows (No. 3, 4) had a magnet in the reticulum close to the foreign body but there was no direct contact between the two. A magnet was administered to cows No. 1 and 2, and radiography of the reticulum was performed for a second time the following day. The magnets were observed in the reticulum however, they did not contact the foreign bodies. Because all the magnets were correctly placed in the reticulum yet, despite close proximity, did not contact the foreign bodies, the latter were thought to be non-magnetic. Cow No. 1 was slaughtered. Left flank laparoruminotomy was performed in the remaining three cows. In all cows, copper foreign bodies ranging in length from 3.0 to 7.0 cm, were found in the reticulum. They had penetrated the reticular wall and were not attached to magnets. The radiographic findings described in the present study are strongly indicative of a non-magnetic foreign body. Ruminotomy is the treatment of choice but slaughter may also be considered

  14. The effects of Dresselhaus and Rashba spin-orbit interactions on the electron tunneling in a non-magnetic heterostructure

    International Nuclear Information System (INIS)

    Lu Jianduo; Li Jianwen

    2010-01-01

    We theoretically investigate the electron transport properties in a non-magnetic heterostructure with both Dresselhaus and Rashba spin-orbit interactions. The detailed-numerical results show that (1) the large spin polarization can be achieved due to Dresselhaus and Rashba spin-orbit couplings induced splitting of the resonant level, although the magnetic field is zero in such a structure, (2) the Rashba spin-orbit coupling plays a greater role on the spin polarization than the Dresselhaus spin-orbit interaction does, and (3) the transmission probability and the spin polarization both periodically change with the increase of the well width.

  15. Giant magnetoimpedance in composite wires with insulator layer between non-magnetic core and soft magnetic shell

    International Nuclear Information System (INIS)

    Buznikov, N.A.; Antonov, A.S.; Granovsky, A.B.; Kim, C.G.; Kim, C.O.; Li, X.P.; Yoon, S.S.

    2006-01-01

    A method for calculation of the magnetoimpedance in composite wires having an insulator layer between non-magnetic core and soft magnetic shell is described. It is assumed that the magnetic shell has a helical anisotropy and the driving current flows through the core only. The distribution of eddy currents and expressions for the impedance are found by means of a solution of Maxwell equations taking into account the magnetization dynamics within the shell governed by the Landau-Lifshitz equation. The effect of the insulator layer on the magnetoimpedance is analyzed

  16. Giant magnetoimpedance in composite wires with insulator layer between non-magnetic core and soft magnetic shell

    Energy Technology Data Exchange (ETDEWEB)

    Buznikov, N.A. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Antonov, A.S. [Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Granovsky, A.B. [Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Kim, C.G. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daejeon 305-764 (Korea, Republic of)]. E-mail: cgkim@cnu.ac.kr; Kim, C.O. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Li, X.P. [Department of Mechanical Engineering and Division of Bioengineering, National University of Singapore, Singapore 119260 (Singapore); Yoon, S.S. [Department of Physics, Andong National University, Andong 760-749 (Korea, Republic of)

    2006-05-15

    A method for calculation of the magnetoimpedance in composite wires having an insulator layer between non-magnetic core and soft magnetic shell is described. It is assumed that the magnetic shell has a helical anisotropy and the driving current flows through the core only. The distribution of eddy currents and expressions for the impedance are found by means of a solution of Maxwell equations taking into account the magnetization dynamics within the shell governed by the Landau-Lifshitz equation. The effect of the insulator layer on the magnetoimpedance is analyzed.

  17. Investigation of technology for manufacturing the non-magnetic temperature-sensitive composite materials and their properties

    International Nuclear Information System (INIS)

    Kobelev, A.G.; Kolesnikov, F.V.; Gul'bin, V.N.; Nikitin, I.S.

    2004-01-01

    Investigation results are presented on structure and properties of nonmagnetic thermobimetals on the basis of beryllium bronze which is used both as active and passive layers. The second layer of thermosensitive element consists of stainless steel 12Kh18N10T, titanium base alloy VT1-0 and aluminum base alloy AD1. The manufacturing of the layered composite materials includes explosion welding, plastic deformation and heat treatment. It is established that strain hardening of the thermobimetals results in an increase of yield strength, microstresses, hardness and specific resistance [ru

  18. Creating a context for excellence and innovation: comparing chief nurse executive leadership practices in magnet and non-magnet hospitals.

    Science.gov (United States)

    Porter-O'grady, Tim

    2009-01-01

    Chief nurse executives create a context for leadership, innovation, and practice in hospitals. It is valuable to get a sense of nurse executives' perceptions regarding their leadership practices and how they value them. Furthermore, it is of interest to see if there is significant differentiation in these perceptions between chief nurse executives in Magnet hospitals and those in non-Magnet hospitals. This article discusses a study of the leadership practices of these 2 groups of nurse executive's leadership practices and reports the results. Concluding is a brief discussion regarding impact and importance of the nurse executive related to excellence and innovation.

  19. Mechanical properties and fatigue strength of high manganese non-magnetic steel/carbon steel welded joints

    International Nuclear Information System (INIS)

    Nakaji, Eiji; Ikeda, Soichi; Kim, You-Chul; Nakatsuji, Yoshihiro; Horikawa, Kosuke.

    1997-01-01

    The dissimilar materials welded joints of high manganese non-magnetic steel/carbon steel (hereafter referred to as DMW joints), in which weld defects such as hot crack or blowhole are not found, were the good quality. Tensile strength of DMW joints was 10% higher than that of the base metal of carbon steel. In the bend tests, the DMW joints showed the good ductility without crack. Charpy absorbed energy at 0(degC) of the DMW joints was over 120(J) in the bond where it seems to be the lowest. Large hardening or softening was not detected in the heat affected zone. Fatigue strength of the DMW joints is almost the same with that of the welded joints of carbon steel/carbon steel. As the fatigue strength of the DMW joints exceeds the fatigue design standard curve of JSSC for carbon steel welded joints, the DMW joints can be treated the same as the welded joints of carbon steel/carbon steel of which strength is lower than that of high manganese non-magnetic steel, from the viewpoint of the fatigue design. (author)

  20. Component masses of young, wide, non-magnetic white dwarf binaries in the Sloan Digital Sky Survey Data Release 7

    Science.gov (United States)

    Baxter, R. B.; Dobbie, P. D.; Parker, Q. A.; Casewell, S. L.; Lodieu, N.; Burleigh, M. R.; Lawrie, K. A.; Külebi, B.; Koester, D.; Holland, B. R.

    2014-06-01

    We present a spectroscopic component analysis of 18 candidate young, wide, non-magnetic, double-degenerate binaries identified from a search of the Sloan Digital Sky Survey Data Release 7 (DR7). All but two pairings are likely to be physical systems. We show SDSS J084952.47+471247.7 + SDSS J084952.87+471249.4 to be a wide DA + DB binary, only the second identified to date. Combining our measurements for the components of 16 new binaries with results for three similar, previously known systems within the DR7, we have constructed a mass distribution for the largest sample to date (38) of white dwarfs in young, wide, non-magnetic, double-degenerate pairings. This is broadly similar in form to that of the isolated field population with a substantial peak around M ˜ 0.6 M⊙. We identify an excess of ultramassive white dwarfs and attribute this to the primordial separation distribution of their progenitor systems peaking at relatively larger values and the greater expansion of their binary orbits during the final stages of stellar evolution. We exploit this mass distribution to probe the origins of unusual types of degenerates, confirming a mild preference for the progenitor systems of high-field-magnetic white dwarfs, at least within these binaries, to be associated with early-type stars. Additionally, we consider the 19 systems in the context of the stellar initial mass-final mass relation. None appear to be strongly discordant with current understanding of this relationship.

  1. Natural radionuclides concentration in underground mine materials

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M., E-mail: talitaolsantos@yahoo.com.br, E-mail: rochaz@cdtn.br, E-mail: mayarapinheiroduarte@gmail.com, E-mail: lauratakahashi@hotmail.com, E-mail: natyfontaveira@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B., E-mail: vgouvea@cnen.gov.br, E-mail: flavia.borges@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: jbsiquei@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are {sup 40}K, as well as, {sup 238}U and {sup 232}Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The {sup 238}U and {sup 232}Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine {sup 226}Ra, {sup 228}Ra and {sup 40}K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

  2. Natural radionuclides concentration in underground mine materials

    International Nuclear Information System (INIS)

    Santos, T.O.; Rocha, Z.; Taveira, N.F.; Takahashi, L.C.; Pineiro, M.M.; Borges, P.F.; Cruz, P.; Gouvea, V.A.; Siqueira, J.B.

    2017-01-01

    Natural Radionuclides are present in earth's environment since its origin. The main radionuclides present are 40 K, as well as, 238 U and 232 Th with their decay products. These radionuclides occur in minerals in different activity concentration associated with geological and geochemical conditions, appearing at different levels from point to point in the world. Underground mines may present a high natural background radiation which is due to the presence of these radiogenic heavy minerals. To address this concern, this work outlines on the characterization of the natural radionuclides presence in underground mines in Brazil which are located in many cases on higher radiation levels bed rocks. The radon concentration was measured by using E-PERM Electrets Ion Chamber, AlphaGUARD and CR-39 track etch detectors. The radon progeny was determined by using DOSEman detector. Radon concentration measurement in groundwater was performed by using RAD7 detector. The 238 U and 232 Th activity concentration in ore and soil samples were determined by using Neutron Activation Analysis using TRIGA MARK I IPR-R1 Reactor. Gamma spectrometry was used to determine 226 Ra, 228 Ra and 40 K activity concentrations. The results show that the natural radioactivity varies considerably from mine to mine and that there are not risks of radiological damage for exposed workers in these cases. Based on these data, recommendations for Brazilian regulatory standards are presented. (author)

  3. Enhancement of nondestructive evaluation techniques for magnetic and nonmagnetic structural components (Final report for doctoral fellowship)

    International Nuclear Information System (INIS)

    Chen, Zhenmao

    2000-03-01

    In this report, research works performed in the Structural Safety Engineering Group of OEC/JNC are summarized as the final report of the doctoral fellowship. The main objective of this study is for the enhancement of the nondestructive evaluation techniques for structural components of both magnetic and nonmagnetic material. Studies in three topics have been carried out aiming at the quantitative evaluation of crack with the eddy current testing and the validation of a natural magnetic field based NDE method for detecting mechanical damages in a paramagnetic material. In the first part of the study, an approach to the reconstruction of the natural crack was proposed and implemented with an idealized crack model for its validation. In the second part, the correlation of the natural magnetization and the mechanical damages in the SUS304 stainless steel was investigated by using an experimental approach. In part 3, an inverse method of the measured magnetic fields is proposed for the reconstruction of magnetic charges in the inspected material by using an optimization method and wavelet. As the first work, an approach to the reconstruction of an idealized natural crack of non-vanishing conductivity is proposed with use of signals of eddy current testing. Two numerical models are introduced at first for modeling the natural crack in order to represented it with a set of crack parameters. A method for the rapid prediction of the eddy current testing signals coming from these idealized cracks is given then by extending a knowledge based fast forward solver to the case of a non-vanishing conductivity. Based on this fast forward solver, the inverse algorithm of conjugate gradient method is updated to identify the crack parameters. Several examples are presented finally as a validation of the proposed strategy. The results show that both the two numerical models can give reasonable reconstruction results for signal of low noise. The model concerning the touch of crack

  4. Effect of nanostructure layout on spin pumping phenomena in antiferromagnet/nonmagnetic metal/ferromagnet multilayered stacks

    Directory of Open Access Journals (Sweden)

    A. F. Kravets

    2017-05-01

    Full Text Available In this work we focus on magnetic relaxation in Mn80Ir20(12 nm/Cu(6 nm/Py(dF antiferromagnet/Cu/ferromagnet (AFM/Cu/FM multilayers with different thickness of the ferromagnetic permalloy layer. An effective FM-AFM interaction mediated via the conduction electrons in the nonmagnetic Cu spacer – the spin-pumping effect – is detected as an increase in the linewidth of the ferromagnetic resonance (FMR spectra and a shift of the resonant magnetic field. We further find experimentally that the spin-pumping-induced contribution to the linewidth is inversely proportional to the thickness of the Py layer. We show that this thickness dependence likely originates from the dissipative dynamics of the free and localized spins in the AFM layer. The results obtained could be used for tailoring the dissipative properties of spintronic devices incorporating antiferromagnetic layers.

  5. The interface of the ferromagnetic metal CoS2 and the nonmagnetic semiconductor FeS2

    KAUST Repository

    Nazir, S.

    2010-11-05

    The electronic and magnetic properties of the cubic pyriteCoS2/FeS2interface are studied using the all-electron full-potential linearized augmented plane wave method. We find that this contact between a ferromagneticmetal and a nonmagnetic semiconductor shows a metallic character. The CoS2 stays close to half-metallicity at the interface, while the FeS2 becomes metallic. The magnetic moment of the Co atoms at the interface slightly decreases as compared to the bulk value and a small moment is induced on the Fe atoms. Furthermore, at the interfaceferromagnetic ordering is found to be energetically favorable as compared to antiferromagnetic ordering.

  6. Enhanced infrared magneto-optical response of the nonmagnetic semiconductor BiTeI driven by bulk Rashba splitting

    Energy Technology Data Exchange (ETDEWEB)

    Demko, L.; Tokura, Y. [Multiferroics Project, ERATO, JST, c/o Department of Applied Physics, University of Tokyo (Japan); Schober, G.A.H. [Institute for Theoretical Physics, University of Heidelberg (Germany); Kocsis, V.; Kezsmarki, I. [Department of Physics, Budapest University of Technology and Economics and Condensed Matter Research Group of the Hungarian Academy of Sciences (Hungary); Bahramy, M.S.; Murakawa, H. [CMRG and CERG, RIKEN ASI (Japan); Lee, J.S.; Arita, R.; Nagaosa, N. [Department of Applied Physics, University of Tokyo (Japan)

    2013-07-01

    We study the magneto-optical (MO) response of the polar semiconducting BiTeI with giant bulk Rashba spin splitting at various carrier densities. Despite being nonmagnetic, the material is found to yield a huge MO activity in the infrared region under moderate magnetic fields (up to 3 T). Our first-principles calculations show that the enhanced MO response of BiTeI comes mainly from the intraband transitions between the Rashba-split bulk conduction bands. These transitions connecting electronic states with opposite spin directions become active due to the presence of strong spin-orbit interaction and give rise to distinct features in the MO spectra with a systematic doping dependence. We predict an even more pronounced enhancement in the low-energy MO response and dc Hall effect near the crossing (Dirac) point of the conduction bands.

  7. Monte Carlo study of the magnetic properties in a bilayer dendrimer structure with non-magnetic layers

    Science.gov (United States)

    Jabar, A.; Masrour, R.

    2017-12-01

    In this paper, we study the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions and magnetic layer effects on the bilayer transitions of a spin-5/2 Blume-Capel model formed by two magnetic blocs separated by a non-magnetic spacer of finite thickness. The thermalization process of magnetization for systems sizes has been given. We have shown that the magnetic order in the two magnetic blocs depend on the thickness of the magnetic layer. In the total magnetization profiles, the susceptibility peaks correspond to the reduced critical temperature. This critical temperature is displaced towards higher temperatures when increasing the number of magnetic layers. In addition, we have discussed and interpreted the behaviors of the magnetic hysteresis loops.

  8. Lattice specific heat for the RMIn5 (R=Gd, La, Y; M=Co, Rh) compounds: Non-magnetic contribution subtraction

    International Nuclear Information System (INIS)

    Facio, Jorge I.; Betancourth, D.; Cejas Bolecek, N.R.; Jorge, G.A.; Pedrazzini, Pablo; Correa, V.F.; Cornaglia, Pablo S.; Vildosola, V.; García, D.J.

    2016-01-01

    We analyze theoretically a common experimental process used to obtain the magnetic contribution to the specific heat of a given magnetic material. In the procedure, the specific heat of a non-magnetic analog is measured and used to subtract the non-magnetic contributions, which are generally dominated by the lattice degrees of freedom in a wide range of temperatures. We calculate the lattice contribution to the specific heat for the magnetic compounds GdMIn 5 (M=Co, Rh) and for the non-magnetic YMIn 5 and LaMIn 5 (M=Co, Rh), using density functional theory based methods. We find that the best non-magnetic analog for the subtraction depends on the magnetic material and on the range of temperatures. While the phonon specific heat contribution of YRhIn 5 is an excellent approximation to the one of GdCoIn 5 in the full temperature range, for GdRhIn 5 we find a better agreement with LaCoIn 5 , in both cases, as a result of an optimum compensation effect between masses and volumes. We present measurements of the specific heat of the compounds GdMIn 5 (M=Co, Rh) up to room temperature where it surpasses the value expected from the Dulong–Petit law. We obtain a good agreement between theory and experiment when we include anharmonic effects in the calculations.

  9. Lattice specific heat for the RMIn{sub 5} (R=Gd, La, Y; M=Co, Rh) compounds: Non-magnetic contribution subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Facio, Jorge I., E-mail: jorge.facio@cab.cnea.gov.ar [Centro Atómico Bariloche and Instituto Balseiro, CNEA, 8400 Bariloche (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Betancourth, D.; Cejas Bolecek, N.R. [Centro Atómico Bariloche and Instituto Balseiro, CNEA, 8400 Bariloche (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Jorge, G.A. [Instituto de Ciencias, Universidad Nacional de General Sarmiento, Buenos Aires (Argentina); Pedrazzini, Pablo; Correa, V.F.; Cornaglia, Pablo S. [Centro Atómico Bariloche and Instituto Balseiro, CNEA, 8400 Bariloche (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); Vildosola, V. [Centro Atómico Constituyentes, CNEA, 1650 San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina); García, D.J. [Centro Atómico Bariloche and Instituto Balseiro, CNEA, 8400 Bariloche (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina)

    2016-06-01

    We analyze theoretically a common experimental process used to obtain the magnetic contribution to the specific heat of a given magnetic material. In the procedure, the specific heat of a non-magnetic analog is measured and used to subtract the non-magnetic contributions, which are generally dominated by the lattice degrees of freedom in a wide range of temperatures. We calculate the lattice contribution to the specific heat for the magnetic compounds GdMIn{sub 5} (M=Co, Rh) and for the non-magnetic YMIn{sub 5} and LaMIn{sub 5} (M=Co, Rh), using density functional theory based methods. We find that the best non-magnetic analog for the subtraction depends on the magnetic material and on the range of temperatures. While the phonon specific heat contribution of YRhIn{sub 5} is an excellent approximation to the one of GdCoIn{sub 5} in the full temperature range, for GdRhIn{sub 5} we find a better agreement with LaCoIn{sub 5}, in both cases, as a result of an optimum compensation effect between masses and volumes. We present measurements of the specific heat of the compounds GdMIn{sub 5} (M=Co, Rh) up to room temperature where it surpasses the value expected from the Dulong–Petit law. We obtain a good agreement between theory and experiment when we include anharmonic effects in the calculations.

  10. Electromagnetic field analyses of two-layer power transmission cables consisting of coated conductors with magnetic and non-magnetic substrates and AC losses in their superconductor layers

    International Nuclear Information System (INIS)

    Nakahata, Masaaki; Amemiya, Naoyuki

    2008-01-01

    Two-dimensional electromagnetic field analyses were undertaken using two representative cross sections of two-layer cables consisting of coated conductors with magnetic and non-magnetic substrates. The following two arrangements were used for the coated conductors between the inner and outer layers: (1) tape-on-tape and (2) alternate. The calculated magnetic flux profile around each coated conductor was visualized. In the case of the non-magnetic substrate, the magnetic field to which coated conductors in the outer layer are exposed contains more perpendicular component to the conductor wide face (perpendicular field component) when compared to that in the inner layer. On the other hand, for the tape-on-tape arrangement of coated conductors with a magnetic substrate, the reverse is true. In the case of the alternate arrangement of the coated conductor with a magnetic substrate, the magnetic field to which the coated conductors in the inner and outer layers are exposed experiences a small perpendicular field component. When using a non-magnetic substrate, the AC loss in the superconductor layer of the coated conductors in the two-layer cables is dominated by that in the outer layer, whereas the reverse is true in the case of a magnetic substrate. When comparing the AC losses in superconductor layers of coated conductors with non-magnetic and magnetic substrates in two-layer cables, the latter is larger than the former, but the influence of the magnetism of substrates on AC losses in superconductor layers is not remarkable

  11. Composition of coarse-grained magnetite from pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area, Kingdom of Saudi Arabia

    Science.gov (United States)

    Overstreet, William C.; Mousa, Hassan; Matzko, John J.

    1985-01-01

    Crystals of magnetite as large as 30 mm long and 7 mm thick are locally present in quartz-rich zones of interior and exterior pegmatite dikes related to plutons of quartz monzonite in the Jabal Lababa area. Niobium, tin, and yttrium are strongly enriched in six specimens of magnetite from interior pegmatite dikes in a small pluton where these elements form geochemical anomalies in nonmagnetic heavy-mineral concentrates from wadi sediment. Less abundant anomalous elements in the magnetite are molybdenum, lead, and zirconium, which also tend to be present in anomalous amounts in the nonmagnetic concentrates from the niobium-bearing pluton. The most anomalous trace element in the magnetite is zinc, which is at least 10 times as abundant as it is in the quartz monzonite plutons or in the nonmagnetic concentrates. The capacity of magnetite to scavenge molybdenum, zinc, niobium, lead, tin, yttrium, and zirconium suggests the possible utility of magnetite as a geochemical sample medium.

  12. Magnetic susceptibility of Dirac fermions, Bi-Sb alloys, interacting Bloch fermions, dilute nonmagnetic alloys, and Kondo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Buot, Felix A., E-mail: fbuot@gmu.edu [Computational Materials Science Center, George Mason University, Fairfax, VA 22030 (United States); TCSE Center, Spintronics Group, Physics Department, University of San Carlos, Talamban, Cebu 6000 (Philippines); C& LB Research Institute, Carmen, Cebu 6005 (Philippines); Otadoy, Roland E.S.; Rivero, Karla B. [TCSE Center, Spintronics Group, Physics Department, University of San Carlos, Talamban, Cebu 6000 (Philippines)

    2017-03-01

    Wide ranging interest in Dirac Hamiltonian is due to the emergence of novel materials, namely, graphene, topological insulators and superconductors, the newly-discovered Weyl semimetals, and still actively-sought after Majorana fermions in real materials. We give a brief review of the relativistic Dirac quantum mechanics and its impact in the developments of modern physics. The quantum band dynamics of Dirac Hamiltonian is crucial in resolving the giant diamagnetism of bismuth and Bi-Sb alloys. Quantitative agreement of the theory with the experiments on Bi-Sb alloys has been achieved, and physically meaningful contributions to the diamagnetism has been identified. We also treat relativistic Dirac fermion as an interband dynamics in uniform magnetic fields. For the interacting Bloch electrons, the role of translation symmetry for calculating the magnetic susceptibility avoids any approximation to second order in the field. The expressions for magnetic susceptibility of dilute nonmagnetic alloys give a firm theoretical foundation of the empirical formulas used in fitting experimental results. The unified treatment of all the above calculations is based on the lattice Weyl-Wigner formulation of discrete phase-space quantum mechanics. For completeness, the magnetic susceptibility of Kondo alloys is also given since Dirac fermions in conduction band and magnetic impurities exhibit Kondo effect.

  13. Nonmagnetic concrete. Guide for the superconductive magnetically levitated train system (Maglev); Hijisei concrete. Chodendo jiki fujoshiki tetsudoyo guide way

    Energy Technology Data Exchange (ETDEWEB)

    Tottori, S; Sato, T [Railway Technical Research Institute, Tokyo (Japan)

    1994-07-01

    Non-magnetization is applied to concrete structures with which magnetic environment is a problem, such as a guideway for superconductive magnetically levitated train system (Maglev) and geomagnetism observation facilities. As an example, this paper introduces the conception and the design methods of guideways for Maglev. If reinforcing bars or tensing materials of common steel are placed close to a vehicle, inductive current is generated in the steel due to moving magnetic field, causing a problem to form part of driving resistance. The inductive current includes loop current and eddy current. The former current may be prevented if the contact resistance in steels with each other is about one ohm or more, but the latter current has no other means but to minimize it as long as the material is electrically conductive. Conceivable measures may include the use as reinforcing bars of non magnetic high Mn-steel with electric specific resistance of 4 to 5 times as large as that for common steel reinforcing bars, and the use of continuous reinforcing fibers such as aramid. The latter material requires strength design especially importantly, but has obtained good result when it was constructed at the experimental linear motor train guideway at Miyazaki, Japan. 5 refs., 6 figs.

  14. Comparison of the enrollment percentages of magnet and non-magnet schools in a large urban school district.

    Directory of Open Access Journals (Sweden)

    Emily Arcia

    2006-12-01

    Full Text Available Are magnet schools in a position to meet diversity ideals? As districts are declared unitary and released from court ordered desegregation, many are framing their commitments to fairness and equity in terms of diversity˜i.e., comparable rates of participation and comparable educational outcomes in all segments the student population. In this study, the enrollment statistics for magnet and contiguous non-magnet public schools in Miami-Dade County Public Schools, a large, urban district that had been released from court ordered desegregation, were compared to each other and to district enrollment averages at two time points: the year the district was declared unitary and four years hence. Findings indicated that within four years of being declared unitary, the gains that the magnet schools had made with regards to Black/non-Black desegregation had eroded substantially. Also, in the four year span, magnet schools had not made significant strides in meeting the diversity ideals adopted by the district at being released from supervision by the court. These findings highlight the difficulty of attaining diversity in student enrollment characteristics when quotas are not used and suggest that recruitment and enrollment policies must be crafted with care if districts are to achieve diversity goals.

  15. Weak turbulence and broad-spectrum excitation in a nonmagnetized electron beam via second-harmonic generation

    International Nuclear Information System (INIS)

    Bogdanov, A.T.

    1990-01-01

    The nonlinear evolution of an initially monoenergetic [ν-bar(t = 0) = (0,0,u)] electron beam propagating in a nonmagnetized dielectric medium of permittivity ε > 1, with initial velocity u ≥ c/√ε (where c is the vacuum speed of light) is investigated. The specific instability of the beam under such conditions is the cause of the generation of a broad spectrum of transverse electromagnetic waves coupled to the simultaneous excitation of the second harmonic of the beam's oscillations, both at the expense of the beam's initial kinetic energy. The system of self-consistent nonlinear equations, describing the particle-field dynamics, is treated in the spirit of the weak-turbulence approach. The integrals of the resulting nonlinear system of equations for the amplitudes of the fields of the electron density are used to evaluate the spectral distribution of the amplitudes in the saturation phase, and hence the efficiency of the transformation of the beam's energy into electromagnetic radiation as a function of the width of the spectrum of the initially present electromagnetic fluctuations. A substantial increase in this efficiency is observed in comparison with the single-mode case. (author)

  16. Temperature dependence of critical current and transport current losses of 4 mm YBCO coated conductors manufactured using nonmagnetic substrate

    Science.gov (United States)

    Kvitkovic, J.; Hatwar, R.; Pamidi, S. V.; Fleshler, S.; Thieme, C.

    2015-12-01

    The temperature dependence of the critical current and AC losses were measured on American Superconductor Corporation's (AMSC) second generation high temperature superconducting (2G HTS) wire produced by Rolling Assisted Biaxially Textured Substrate (RABiTS) and Metal Organic Deposition (MOD) process. Wires manufactured with two types of substrates were characterized. The magnetic substrate with composition Ni5a%W exhibits a magnetic signature and has non-negligible AC losses in AC power applications. A new nonmagnetic substrate with an alloy composition Ni9a%W has been developed by AMSC to address the AC losses in 2G HTS. The data presented show that the performance of the new conductor is identical to the conductor with magnetic substrate in terms of critical current density. The data on AC losses demonstrate the absence of ferromagnetic loss component in the new conductor and significantly reduced AC losses at low to moderate values of I/Ic. The reduced losses will translate into reduced capital costs and lower operating costs of superconducting electrical devices for AC applications.

  17. Different doping effect on physical properties of non-magnetic Pt and Ga in CaFe4As3

    International Nuclear Information System (INIS)

    Wu, Dapeng

    2015-01-01

    Highlights: • CaFe 3.64 Pt 0.36 As 3 and CaFe 3.64 Ga 0.36 As 3 were grown using Sn flux method. • The two magnetic transition temperatures of CaFe 4 As 3 remain untouched upon Pt or Ga doping. • The effects of Pt and Ga doping give a different modification of physical properties and electronic structure in CaFe 4 As 3 . • The magnetic structure of CaFe 4 As 3 is insusceptible to non-magnetic dopants. - Abstract: We have successfully doped Pt and Ga into CaFe 4 As 3 and investigated the structure and physical properties of CaFe 3.64 X 0.36 As 3 (X = Pt, Ga). Two magnetic transition temperatures remain unchanged upon Pt or Ga doping, as confirmed by specific heat, electrical resistivity and magnetic susceptibility. The electrical resistivity of CaFe 4 As 3 is reduced by approximately half with Pt dopant but increases by an order of magnitude with Ga doping, consistent with the changes in their Hall coefficients, which indicates the effects of Pt and Ga doping give us a different modification on physical properties and electronic structure in CaFe 4 As 3

  18. A non-magnetic spacer layer effect on spin layers (7/2,3) in a bi-layer ferromagnetic dendrimer structure: Monte Carlo study

    Science.gov (United States)

    Jabar, A.; Tahiri, N.; Bahmad, L.; Benyoussef, A.

    2016-11-01

    A bi-layer system consisting of layers of spins (7/2, 3) in a ferromagnetic dendrimer structure, separated by a non-magnetic spacer, is studied by Monte Carlo simulations. The effect of the RKKY interactions is investigated and discussed for such system. It is shown that the magnetic properties in the two magnetic layers depend strongly on the thickness of the magnetic and non-magnetic layers. The total magnetizations and susceptibilities are studied as a function of the reduced temperature. The effect of the reduced exchange interactions as well as the reduced crystal field is outlined. On other hand, the critical temperature is discussed as a function of the magnetic layer values. To complete this study we presented and discussed the magnetic hysteresis cycles.

  19. Influence of nonmagnetic disorder on specific heat and electrical resistivity in Kondo lattice system CePd{sub 1−x}Ge{sub x}In

    Energy Technology Data Exchange (ETDEWEB)

    Gnida, D., E-mail: d.gnida@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław (Poland); Dominyuk, N.; Zaremba, V. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mephodiya Str. 6, 79005 Lviv (Ukraine); Kaczorowski, D. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław (Poland)

    2015-02-15

    Highlights: • Interplay of Kondo and RKKY interactions in the presence of nonmagnetic disorder. • Suppression of the coherent Kondo state by nonmagnetic impurities. • Observation of quantum interference phenomena in Ce-based Kondo system. • Coexistence of incoherent Kondo effect and Altshuler-Aronov quantum correction. - Abstract: The alloy system CePd{sub 1−x}Ge{sub x}In with 0.1⩽x⩽0.4 was investigated by means of heat capacity and electrical resistivity measurements. Its low-temperature behavior has been found to be governed by the interplay of Kondo effect and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in the presence of atomic disorder in nonmagnetic atoms sublattice. The coherent Kondo state, observed for CePdIn, gradually vanishes with increasing the Ge-content. The incoherent Kondo state, which characterizes Ge-rich alloys, appears very sensitive to applied magnetic field. The observed systematic changes in the temperature- and field-dependent electrical transport in CePd{sub 1−x}Ge{sub x}In manifest the important role of quantum correction due to electron-electron interactions in weakly localized regime.

  20. Non-magnetic impurity effect on suppression of Tc and gap evolution in the two-gap superconductor Lu2Fe3Si5

    International Nuclear Information System (INIS)

    Nakajima, Y.; Hidaka, H.; Tamegai, T.

    2013-01-01

    Highlights: ► Non-magnetic impurities suppress T c and the amplitude of gaps in Lu 2 Fe 3 Si 5 . ► Critical scattering rate is higher than that expected in s ± -pairing scenario. ► The evolution of two distinct gaps dose not show merging the amplitude of gaps. -- Abstract: We report the suppression of T c and the evolution of amplitudes of the two gaps with the introduction of non-magnetic impurities in a two-gap superconductor Lu 2 Fe 3 Si 5 . While T c rapidly decreases by a small amount of substitution of Sc for Lu, the suppression of T c is more than ten times slower than that expected from the Abrikosov–Gor’kov equation describing the reduction of T c in a superconductor with sign reversal in the gap function. The evolution of two distinct gaps by the introduction of non-magnetic impurities does not show merging the amplitude of two gaps, which is strikingly different from the typical two-gap superconductor MgB 2

  1. Digestion of Alumina from Non-Magnetic Material Obtained from Magnetic Separation of Reduced Iron-Rich Diasporic Bauxite with Sodium Salts

    Directory of Open Access Journals (Sweden)

    Guanghui Li

    2016-11-01

    Full Text Available Recovery of iron from iron-rich diasporic bauxite ore via reductive roasting followed by magnetic separation has been explored recently. However, the efficiency of alumina extraction in the non-magnetic materials is absent. In this paper, a further study on the digestion of alumina by the Bayer process from non-magnetic material obtained after magnetic separation of reduced iron-rich diasporic bauxite with sodium salts was investigated. The results indicate that the addition of sodium salts can destroy the original occurrences of iron-, aluminum- and silicon-containing minerals of bauxite ore during reductive roasting. Meanwhile, the reactions of sodium salts with complex aluminum- and silicon-bearing phases generate diaoyudaoite and sodium aluminosilicate. The separation of iron via reductive roasting of bauxite ore with sodium salts followed by magnetic separation improves alumina digestion in the Bayer process. When the alumina-bearing material in bauxite ore is converted into non-magnetic material, the digestion temperature decreases significantly from 280 °C to 240 °C with a nearly 99% relative digestion ratio of alumina.

  2. Evaluation of technical, economic and financial feasibility for recycling and reprocessing of radioactive waste from a remediation work of low and medium activity for the extraction of heavy minerals - 59231

    International Nuclear Information System (INIS)

    Raposo de Almeida, Rodrigo; Mortagua, Valter J.G.

    2012-01-01

    Document available in abstract form only. Full text of publication follows: This paper aims to present the methodology and criteria used for the destination, discard and reuse of waste from the remediation activities of soil contaminated by radioactive waste of low activity in the USIN Plant. The site is located in Sao Paulo city, the city with the largest population of Brazil, with approximately 11 million inhabitants. As the environmental agency in Sao Paulo state, in this neighborhood there are several cases of severe contamination of soil and groundwater. The situation of contamination is so severe that it is forbidden the use of groundwater in the region for an indefinite period. Site of the plant running in a monazite processing plant for extraction of rare earths, have been filed across the land several fractions of soil containing monazite sand. In order to guide the remediation of the area for unrestricted use, was a plan for remediation of radioactive waste characterization based on geological, hydrogeological and environmental extensive in the area. From the calculation of the dose was established that the fractions of soil with concentrations of 226 Ra and 228 Ra below 0.5 Bq/g result in additional effective dose less than 1.0 mSv/yr and therefore can be kept on the ground

  3. Comparison between the measurements of Radon Gas Concentrations and γ-ray intensities in Exploring the Black Sands at El-Burullus Beach

    International Nuclear Information System (INIS)

    Abdel-Razek, Y.A; Bakhit, A.F

    2009-01-01

    Ten well-located monitoring stations along El-Burullus beach were chosen to measure radon gas concentrations in the beach sands below surface, and γ-ray intensities at 10 cm above the surface. These stations were chosen to represent apparent concentrations of the black sands. Sand samples were collected from the different stations and analyzed to study the relation between the concentrations of the heavy minerals and the measured radon concentrations or the measured γ-ray intensities at these stations. It was found that radon gas concentrations measured at 6:00 Pm were about 2.82 times those measured at 1 :00 Pm due to diurnal variation of temperature. Measurements of radon gas concentrations inside the beach sands are found to be more reliable in qualitative exploration of black sands than the measurements of γ-ray intensities above the shore sands due to the random arrangement of the layers of these sands below surface

  4. Antiferromagnetic vs. non-magnetic ε phase of solid oxygen. Periodic density functional theory studies using a localized atomic basis set and the role of exact exchange.

    Science.gov (United States)

    Ramírez-Solís, A; Zicovich-Wilson, C M; Hernández-Lamoneda, R; Ochoa-Calle, A J

    2017-01-25

    The question of the non-magnetic (NM) vs. antiferromagnetic (AF) nature of the ε phase of solid oxygen is a matter of great interest and continuing debate. In particular, it has been proposed that the ε phase is actually composed of two phases, a low-pressure AF ε 1 phase and a higher pressure NM ε 0 phase [Crespo et al., Proc. Natl. Acad. Sci. U. S. A., 2014, 111, 10427]. We address this problem through periodic spin-restricted and spin-polarized Kohn-Sham density functional theory calculations at pressures from 10 to 50 GPa using calibrated GGA and hybrid exchange-correlation functionals with Gaussian atomic basis sets. The two possible configurations for the antiferromagnetic (AF1 and AF2) coupling of the 0 ≤ S ≤ 1 O 2 molecules in the (O 2 ) 4 unit cell were studied. Full enthalpy-driven geometry optimizations of the (O 2 ) 4 unit cells were done to study the pressure evolution of the enthalpy difference between the non-magnetic and both antiferromagnetic structures. We also address the evolution of structural parameters and the spin-per-molecule vs. pressure. We find that the spin-less solution becomes more stable than both AF structures above 50 GPa and, crucially, the spin-less solution yields lattice parameters in much better agreement with experimental data at all pressures than the AF structures. The optimized AF2 broken-symmetry structures lead to large errors of the a and b lattice parameters when compared with experiments. The results for the NM model are in much better agreement with the experimental data than those found for both AF models and are consistent with a completely non-magnetic (O 2 ) 4 unit cell for the low-pressure regime of the ε phase.

  5. 'Gigantic' increase of AFMR frequencies induced by nonmagnetic impurity ions in orthoferrites RFe1-xAlxO3 (R=Gd,Tb)

    International Nuclear Information System (INIS)

    Mukhin, A.A.; Parsegov, I.Yu.

    1996-01-01

    We observed a 'gigantic' increase (up to three times) of the AFMR frequencies ν 1,2 with decreasing temperature in GdFe 0.9 Al 0.1 O 3 and TbFe 0.925 Al 0.075 O 3 in contrast to pure GdFeO 3 and TbFeO 3 . The effects observed are explained by the appearance of an additional exchange field H mv ∼20 -36 kOe on rare-earth ions due to decompensation of the surrounding antiferromagnetically ordered Fe ions near nonmagnetic impurity ions. (orig.)

  6. RADIOMETRIC TECHNIQUES IN HEAVY MINERAL EXPLORATION AND EXPLOITATION

    NARCIS (Netherlands)

    DEMEIJER, RJ; TANCZOS, IC; STAPEL, C

    1994-01-01

    In recent years the Environmental Research Group of the KVI has been developing a number of radiometric techniques that may be employed in mineral sand exploration. These techniques involve: radiometric fingerprinting for assessing sand provenances and mineralogical composition; thermoluminescence

  7. Status of heavy mineral investigation off Konkan coast

    Digital Repository Service at National Institute of Oceanography (India)

    Nambiar, A.R.; Sukumaran, P.V.; Zaheer, B.; Venkataramana, P.; Kannan, S.T.; Pai, P.R.; Rahothaman, V.K.; Gujar, S.; Srinivas, K.

    stream_size 2 stream_content_type text/plain stream_name GSI_News_Lett_(Mar_Wing)_8_5.pdf.txt stream_source_info GSI_News_Lett_(Mar_Wing)_8_5.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  8. Provenance analyses of the heavy mineral beach sands of the ...

    Indian Academy of Sciences (India)

    18

    Annaba displays an average temperature of 18.4 °C throughout the year. Rain fall averages 712 mm .... Concrete slabs cover the back of the shoreline. Only a ..... The rare earth element behavior of whole sand and rock. In order to identify the ...

  9. Heavy mineral suite in the shelf sediments off Madras coast

    Digital Repository Service at National Institute of Oceanography (India)

    Setty, M.G.A.P.; Rajamanickam, G.V.

    found at 131 m and 183 m indicates their derivation from the present shore line and the provenance. The abundance of unstable minerals like hornblende and augite at depths of 50 and 131 m (sta. nos. 3 and 7) with corresponding lower values at 73 and 183...

  10. Heavy mineral placers off Kalbadevi Bay, Ratnagiri, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    , Human Corporation, Human Series, Model Human Power 1+, Korea) to remove salt. The carbonates, organic matter and ferruginous coatings were removed by treating with 1:10 HCl, H 2 O 2 (30 % by vol.) and SnCl 2 respectively. Representative dried samples...

  11. Geochemistry of dark coastal heavy-mineral beaches sand (Annaba ...

    African Journals Online (AJOL)

    Acer

    3 Institute of Earth and Environmental Science, University of Potsdam, ... Some beaches are characterized by a red-brownish sand colour, the Ain Achir and the ... The occurrence of clays has been determined using the methyl-blue method.

  12. Heavy mineral variation in the deep sea sediment of southeastern ...

    Indian Academy of Sciences (India)

    instability of the sediments and rapid erosion in the source region. The characteristic HM .... stable domain/superparamagnetic boundary and their delayed response ..... offshore areas – their nature, origin, economic potential and exploration ...

  13. Non-magnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Scarpulla, M.A.; Stone, P.R.; Sharp, I.D.; Haller, E.E.; Dubon, O.D.; Beeman, J.W.; Yu, K.M.

    2008-02-05

    The electronic and magnetic effects of intentional compensation with non-magnetic donors are investigated in the ferromagnetic semiconductors Ga1-xMnxAs and Ga1-xMnxP synthesized using ion implantation and pulsed-laser melting (II-PLM). It is demonstrated that compensation with non-magnetic donors and MnI have similarqualitative effects on materials properties. With compensation TC decreases, resistivity increases, and stronger magnetoresistance and anomalous Hall effect attributed to skew scattering are observed. Ga1-xMnxAs can be controllably compensated with Te through a metal-insulator transition through which the magnetic and electrical properties vary continuously. The resistivity of insulating Ga1-xMnxAs:Te can be described by thermal activation to the mobility edge and simply-activated hopping transport. Ga1-xMnxP doped with S is insulating at all compositions but shows decreasing TC with compensation. The existence of a ferromagnetic insulating state in Ga1-xMnxAs:Te and Ga1-xMnxP:S having TCs of the same order as the uncompensated materials demonstrates that localized holes are effective at mediating ferromagnetism in ferromagnetic semiconductors through the percolation of ferromagnetic 'puddles' which at low temperatures.

  14. Is the ground state of 5d4 double-perovskite Iridate Ba2YIrO6 magnetic or nonmagnetic?

    Science.gov (United States)

    Gong, Hoshin; Kim, Kyoo; Kim, Beom Hyun; Kim, Bongjae; Kim, Junwon; Min, B. I.

    2018-05-01

    We have investigated electronic structures and magnetic properties of double perovskite Iridate Ba2YIrO6 with 5d4 configuration, employing the exact diagonalization method for multi-site clusters. We have considered a many-body Hamiltonian for all d states (eg and t2g) including all relevant physical parameters such as the Coulomb correlation, spin-orbit coupling, crystal-field effect, and Hund coupling. We have found that the ground state of Ba2YIrO6 is nonmagnetic and that the Hund coupling plays an important role in the magnetic properties of the 5d4 systems, unlike the well-studied 5d5 systems.

  15. Optimization of a partially non-magnetic primary radiation shielding for the triple-axis spectrometer PANDA at the Munich high-flux reactor FRM-II

    CERN Document Server

    Pyka, N M; Rogov, A

    2002-01-01

    Monte Carlo simulations have been used to optimize the monochromator shielding of the polarized cold-neutron triple-axis spectrometer PANDA at the Munich high-flux reactor FRM-II. By using the Monte Carlo program MCNP-4B, the density of the total spectrum of incoming neutrons and gamma radiation from the beam tube SR-2 has been determined during the three-dimensional diffusion process in different types of heavy concrete and other absorbing material. Special attention has been paid to build a compact and highly efficient shielding, partially non-magnetic, with a total biological radiation dose of less than 10 mu Sv/h at its outsides. Especially considered was the construction of an albedo reducer, which serves to reduce the background in the experiment outside the shielding. (orig.)

  16. Concentrated Ownership

    DEFF Research Database (Denmark)

    Rose, Caspar

    2014-01-01

    This entry summarizes the main theoretical contributions and empirical findings in relation to concentrated ownership from a law and economics perspective. The various forms of concentrated ownership are described as well as analyzed from the perspective of the legal protection of investors......, especially minority shareholders. Concentrated ownership is associated with benefits and costs. Concentrated ownership may reduce agency costs by increased monitoring of top management. However, concentrated ownership may also provide dominating owners with private benefits of control....

  17. Low cyclic fatigue behavior of 32 % Mn nonmagnetic steel and the effects of C and N in liquid nitrogen and liquid helium

    International Nuclear Information System (INIS)

    Shibata, Koji; Fujita, Toshio

    1987-01-01

    The effects of testing temperature, C, and N on the low cyclic deformation behavior of 32 % Mn non-magnetic steels have been investigated in ambient air, liquid nitrogen, and liquid helium. It was observed that several problems exsisted in fatigue tests in liquid helium due to special phenomena occurred at very low temperatures. The steel containing 0.3 % N, which showed large fatigue softening at room temperature, increased the trend toward the softening at low temperatures. The steel containing 0.14 % C and 0.13 % N also increased the tendency of softening with the temperature decrease, while it was not so large at room temperature. Dislocation configuration in steels showing the softening tended to be mainly planne at very low temperatures same as at room temperature. The steel with a very low content of C and N, the 0.3 % C steel, and the 0.12 % N steel did not show the softening at low temperatures, but showed only fatigue hardening. The hardening of the former two steels increased remarkably as the temperature decreased. This phenomenon was attributable to ε martensite induced by the cyclic deformation. The fatigue softening behavior observed at low temperatures could qualitatively be explained with the hypothesis that the softening occurred through the breakdown of solid solution strengthening due to IS complexes during the cyclic deformation. (author)

  18. Quantum size effects on spin-transfer torque in a double barrier magnetic tunnel junction with a nonmagnetic-metal (semiconductor) spacer

    International Nuclear Information System (INIS)

    Daqiq, Reza; Ghobadi, Nader

    2016-01-01

    We study the quantum size effects of an MgO-based double barrier magnetic tunnel junction with a nonmagnetic-metal (DBMTJ-NM) (semiconductor (DBMTJ-SC)) spacer on the charge current and the spin-transfer torque (STT) components using non-equilibrium Green's function (NEGF) formalism. The results show oscillatory behavior due to the resonant tunneling effect depending on the structure parameters. We find that the charge current and the STT components in the DBMTJ-SC demonstrate the magnitude enhancement in comparison with the DBMTJ-NM. The bias dependence of the STT components in a DBMTJ-NM shows different behavior in comparison with spin valves and conventional MTJs. Therefore, by choosing a specific SC spacer with suitable thickness in a DBMTJ the charge current and the STT components significantly increase so that one can design a device with high STT and faster magnetization switching. - Highlights: • The quantum size effects are studied in double barrier magnetic tunnel junctions. • Spin torque (ST) components oscillate for increasing of middle spacer thicknesses. • Due to the resonant tunneling in the quantum well, oscillations have appeared. • By replacement a metal spacer with a semiconductor (ZnO) ST has increased. • The ST components vs. bias show gradually decreasing unlike spin valves or MTJs.

  19. Magnetic versus nonmagnetic ion substitution effects on Tc in the La-Sr-Cu-O and Nd-Ce-Cu-O systems

    International Nuclear Information System (INIS)

    Tarascon, J.M.; Wang, E.; Kivelson, S.; Bagley, B.G.; Hull, G.W.; Ramesh, R.

    1990-01-01

    The effects of a substitution for Cu by other 3d metals (Ni, Co, and Zn) on T c in the Nd-Ce-Cu-O system was studied and compared with effects of the same ions on T c in the La-Sr-Cu-O system. We found (1) Zn suppresses T c more slowly in the Nd than in the La systems, so the disorder produced by the nonmagnetic ions is less important in the Nd system, (2) Ni and Co depress T c more quickly in the Nd than in the La system, showing that the magnetic pair breaking is stronger in the Nd system, and (3) in the La system the magnetism of the dopant has no effect on T c . Thus, within the same chemical system (cuprates) we find that as the correlation length is increased one obtains more familiar BCS-type behavior. We suggest that much of the behavior of the various high-T c oxides may be simply a function of the correlation length

  20. Resonant Hall effect under generation of a self-sustaining mode of spin current in nonmagnetic bipolar conductors with identical characters between holes and electrons

    Science.gov (United States)

    Sakai, Masamichi; Takao, Hiraku; Matsunaga, Tomoyoshi; Nishimagi, Makoto; Iizasa, Keitaro; Sakuraba, Takahito; Higuchi, Koji; Kitajima, Akira; Hasegawa, Shigehiko; Nakamura, Osamu; Kurokawa, Yuichiro; Awano, Hiroyuki

    2018-03-01

    We have proposed an enhancement mechanism of the Hall effect, the signal of which is amplified due to the generation of a sustaining mode of spin current. Our analytic derivations of the Hall resistivity revealed the conditions indispensable for the observation of the effect: (i) the presence of the transverse component of an effective electric field due to spin splitting in chemical potential in addition to the longitudinal component; (ii) the simultaneous presence of holes and electrons each having approximately the same characteristics; (iii) spin-polarized current injection from magnetized electrodes; (iv) the boundary condition for the transverse current (J c, y = 0). The model proposed in this study was experimentally verified by using van der Pauw-type Hall devices consisting of the nonmagnetic bipolar conductor YH x (x ≃ 2) and TbFeCo electrodes. Replacing Au electrodes with TbFeCo electrodes alters the Hall resistivity from the ordinary Hall effect to the anomalous Hall-like effect with an enhancement factor of approximately 50 at 4 T. We interpreted the enhancement phenomenon in terms of the present model.

  1. Effect of non-magnetic intermediate layer on film structure, magnetic properties, and noise characteristics of FeCSi soft magnetic multilayers

    International Nuclear Information System (INIS)

    Kawano, Hiroyasu; Morikawa, Takeshi; Matsumoto, Koji; Shono, Keiji

    2004-01-01

    The film structures, magnetic properties, and noise characteristics of soft magnetic multilayers with alternately stacked FeCSi soft magnetic layers and non-magnetic intermediate layers were investigated. The FeCSi layers in an as-deposited multilayer with C or Ta intermediate layers had the same nano-sized fine crystalline grains and low media noise as an as-deposited FeCSi monolayer. Amorphous C intermediate layers suppressed the amplitude of spike noise especially well. In contrast, FeCSi layers in an as-deposited multilayer with Cr or Ti intermediate layers were composed of coarse crystalline grains, which increased the media noise. The crystallographic match at the interface between the layers in a multilayer could explain these phenomena. The similarity of the atomic arrangement at the interface between layers and the crystallographic match of less than a few percent for the distance between atoms crystallized FeCSi layers with nano-sized fine crystalline grains into ones with coarse crystalline grains during deposition

  2. Quantum size effects on spin-transfer torque in a double barrier magnetic tunnel junction with a nonmagnetic-metal (semiconductor) spacer

    Energy Technology Data Exchange (ETDEWEB)

    Daqiq, Reza; Ghobadi, Nader

    2016-07-15

    We study the quantum size effects of an MgO-based double barrier magnetic tunnel junction with a nonmagnetic-metal (DBMTJ-NM) (semiconductor (DBMTJ-SC)) spacer on the charge current and the spin-transfer torque (STT) components using non-equilibrium Green's function (NEGF) formalism. The results show oscillatory behavior due to the resonant tunneling effect depending on the structure parameters. We find that the charge current and the STT components in the DBMTJ-SC demonstrate the magnitude enhancement in comparison with the DBMTJ-NM. The bias dependence of the STT components in a DBMTJ-NM shows different behavior in comparison with spin valves and conventional MTJs. Therefore, by choosing a specific SC spacer with suitable thickness in a DBMTJ the charge current and the STT components significantly increase so that one can design a device with high STT and faster magnetization switching. - Highlights: • The quantum size effects are studied in double barrier magnetic tunnel junctions. • Spin torque (ST) components oscillate for increasing of middle spacer thicknesses. • Due to the resonant tunneling in the quantum well, oscillations have appeared. • By replacement a metal spacer with a semiconductor (ZnO) ST has increased. • The ST components vs. bias show gradually decreasing unlike spin valves or MTJs.

  3. Different doping effect on physical properties of non-magnetic Pt and Ga in CaFe{sub 4}As{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Dapeng

    2015-02-25

    Highlights: • CaFe{sub 3.64}Pt{sub 0.36}As{sub 3} and CaFe{sub 3.64}Ga{sub 0.36}As{sub 3} were grown using Sn flux method. • The two magnetic transition temperatures of CaFe{sub 4}As{sub 3} remain untouched upon Pt or Ga doping. • The effects of Pt and Ga doping give a different modification of physical properties and electronic structure in CaFe{sub 4}As{sub 3}. • The magnetic structure of CaFe{sub 4}As{sub 3} is insusceptible to non-magnetic dopants. - Abstract: We have successfully doped Pt and Ga into CaFe{sub 4}As{sub 3} and investigated the structure and physical properties of CaFe{sub 3.64}X{sub 0.36}As{sub 3} (X = Pt, Ga). Two magnetic transition temperatures remain unchanged upon Pt or Ga doping, as confirmed by specific heat, electrical resistivity and magnetic susceptibility. The electrical resistivity of CaFe{sub 4}As{sub 3} is reduced by approximately half with Pt dopant but increases by an order of magnitude with Ga doping, consistent with the changes in their Hall coefficients, which indicates the effects of Pt and Ga doping give us a different modification on physical properties and electronic structure in CaFe{sub 4}As{sub 3}.

  4. Elliptical concentrators.

    Science.gov (United States)

    Garcia-Botella, Angel; Fernandez-Balbuena, Antonio Alvarez; Bernabeu, Eusebio

    2006-10-10

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used to produce optical devices, including the use of reflective and refractive components or inverse engineering techniques. However, many of these optical components are based on translational symmetries, rotational symmetries, or free-form surfaces. We study a new family of nonimaging concentrators called elliptical concentrators. This new family of concentrators provides new capabilities and can have different configurations, either homofocal or nonhomofocal. Translational and rotational concentrators can be considered as particular cases of elliptical concentrators.

  5. Effects of density on cross-shore sediment transport

    NARCIS (Netherlands)

    Bosboom, J.; de Meijer, R.J.; Kraus, N.C.; McDougal, W.G.

    1999-01-01

    After the discovery of high concentrations of heavy minerals on the beach of the Dutch barrier-island Ameland, the radiometric fingerprinting technique was developed to assess offshore heavy-mineral concentrations. These measurements revealed cross-shore variations in the heavy-mineral

  6. Investigations of mechanical, electronic, and magnetic properties of non-magnetic MgTe and ferro-magnetic Mg0.75TM0.25Te (TM = Fe, Co, Ni): An ab-initio calculation

    International Nuclear Information System (INIS)

    Mahmood, Q; Alay-e-Abbas, S M; Mahmood, I; Noor, N A; Asif, Mahmood

    2016-01-01

    The mechanical, electronic and magnetic properties of non-magnetic MgTe and ferro-magnetic (FM) Mg 0.75 TM 0.25 Te (TM = Fe, Co, Ni) in the zinc-blende phase are studied by ab-initio calculations for the first time. We use the generalized gradient approximation functional for computing the structural stability, and mechanical properties, while the modified Becke and Johnson local (spin) density approximation (mBJLDA) is utilized for determining the electronic and magnetic properties. By comparing the energies of non-magnetic and FM calculations, we find that the compounds are stable in the FM phase, which is confirmed by their structural stabilities in terms of enthalpy of formation. Detailed descriptions of elastic properties of Mg 0.75 TM 0.25 Te alloys in the FM phase are also presented. For electronic properties, the spin-polarized electronic band structures and density of states are computed, showing that these compounds are direct bandgap materials with strong hybridizations of TM 3d states and Te p states. Further, the ferromagnetism is discussed in terms of the Zener free electron model, RKKY model and double exchange model. The charge density contours in the (110) plane are calculated to study bonding properties. The spin exchange splitting and crystal field splitting energies are also calculated. The distribution of electron spin density is employed in computing the magnetic moments appearing at the magnetic sites (Fe, Co, Ni), as well as at the non-magnetic sites (Mg, Te). It is found that the p–d hybridization causes not only magnetic moments on the magnetic sites but also induces negligibly small magnetic moments at the non-magnetic sites. (paper)

  7. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  8. Concentrator Photovoltaics

    CERN Document Server

    Luque, Antonio L

    2007-01-01

    Photovoltaic solar-energy conversion is one of the most promising technologies for generating renewable energy, and conversion of concentrated sunlight can lead to reduced cost for solar electricity. In fact, photovoltaic conversion of concentrated sunlight insures an efficient and cost-effective sustainable power resource. This book gives an overview of all components, e.g. cells, concentrators, modules and systems, for systems of concentrator photovoltaics. The authors report on significant results related to design, technology, and applications, and also cover the fundamental physics and market considerations. Specific contributions include: theory and practice of sunlight concentrators; an overview of concentrator PV activities; a description of concentrator solar cells; design and technology of modules and systems; manufacturing aspects; and a market study.

  9. Detailed investigation of thermal and electron transport properties in strongly correlated compound Ce6Pd12In5 and its nonmagnetic analog La6Pd12In5

    Science.gov (United States)

    Falkowski, M.; Krychowski, D.; Strydom, A. M.

    2016-11-01

    An in-depth study of thermal and electron transport properties including thermal conductivity κ(T), thermoelectric power S(T), and electrical resistivity ρ(T) of the heavy fermion Kondo lattice Ce6Pd12In5 and its nonmagnetic reference compound La6Pd12In5 is presented. The absolute κ(T) value of Ce6Pd12In5 is smaller that than of La6Pd12In5, which indicates that conduction electron-4f electron scattering has a large impact on the reduction of thermal conductivity. The isolated 4f electron contributions to the electrical resistivity ρ 4 f (T), electronic thermal resistivity displayed in the form W e l , 4 f (T) .T, and thermoelectric power S 4 f (T) reveal a low- and high-temperature -lnT behaviour characteristic of Kondo systems with strong crystal-electric field (CEF) interactions. The analysis of phonon scattering processes of lattice thermal conductivity κph(T) in (Ce, La)6Pd12In5 was performed over the whole accessible temperature range according to the Callaway model. In the scope of a theoretical approach based on the perturbation type calculation, we were able to describe our experimental data of ρ 4 f (T) and W e l , 4 f (T) .T by using the model incorporating simultaneously the Kondo effect in the presence of the CEF splitting, as it is foreseen in the framework of the Cornut-Coqblin and Bhattacharjee-Coqblin theory. Considering the fact that there are not many cases of similar studies at all, we also show the numerical calculations of temperature-dependent behaviour of spin-disorder resistivity ρs(T), magnetic resistivity ρ 4 f (T), and occupation number ⟨ N i ⟩ due to the various types of degeneracy of the ground state multiplet of Ce 3 + (J = 5/2).

  10. Concentrating Radioactivity

    Science.gov (United States)

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  11. In-gap quasiparticle excitations induced by non-magnetic Cu impurities in Na(Fe0.96Co0.03Cu0.01)As revealed by scanning tunnelling spectroscopy

    Science.gov (United States)

    Yang, Huan; Wang, Zhenyu; Fang, Delong; Deng, Qiang; Wang, Qiang-Hua; Xiang, Yuan-Yuan; Yang, Yang; Wen, Hai-Hu

    2013-01-01

    The origin of superconductivity in the iron pnictides remains unclear. One suggestion is that superconductivity in these materials has a magnetic origin, which would imply a sign-reversal s± pairing symmetry. Another suggests it is the result of orbital fluctuations, which would imply a sign-equal s++ pairing symmetry. There is no consensus yet which of these two distinct and contrasting pairing symmetries is the right one in iron pnictide superconductors. Here we explore the nature of the pairing symmetry in the superconducting state of Na(Fe0.97−xCo0.03Cux)As by probing the effect of scattering of Cooper pairs by non-magnetic Cu impurities. Using scanning tunnelling spectroscopy, we identify the in-gap quasiparticle states induced by the Cu impurities, showing signatures of Cooper pair breaking by these non-magnetic impurities–a process that is only consistent with s± pairing. This experiment provides strong evidence for the s± pairing. PMID:24248097

  12. Ferromagnetism in 4H-GaN polytype doped by non-magnetic light elements Li, Be, B, C, O, F, Ne, Na, and Mg: Ab-initio study

    International Nuclear Information System (INIS)

    Torrichi, M.; Ferhat, M.; Bouhafs, B.

    2016-01-01

    Using density-functional theory within the generalized-gradient approximation, we explore the magnetic behavior induced by nonmagnetic impurity X atoms, such as Li, Be, B, C, O, F, Ne, Na, and Mg on cation site in 4H-GaN polytype. The results reveal that Ne doped 4H-GaN has the highest magnetic moment of 3µ B , whereas Mg doped 4H-GaN has the lowest magnetic moment of 0.75µ B . Among the systems studied 4H-GaN doped Ne has been found to be half-metallic, whereas 4H-GaN doped F and Na are found to be nearly half-metallic. The partial density of states evidence that magnetism is achieved through a p-p like coupling between the impurity and the host 2p states. Furthermore, we inspect whether there exists a relationship between the spin-polarization and the local structure around the doping X atoms. It is found that for all the compounds studied, the total magnetic moment increases with increasing the X–N bond lengths. Interestingly, 4H-GaN:Be becomes ferromagnetic with increasing the Be–N bond length, whereas 4H-GaN:Na and 4H-GaN:F become half-metallic with increasing Na–N and F–N bond lengths. - Highlights: • The partial densities of states of 4H-GaN polytype doped light nonmagnetic elements have been investigated. • We found that 4H-GaN:Ne is half metallic. • We found that N atoms induced strong local magnetic. • We found that doping with half-filled X-s impurity states promotes ferromagnetism. • We found that doping with full-filled X-s impurity annihilates ferromagnetism.

  13. Carrier concentration induced ferromagnetism in semiconductors

    International Nuclear Information System (INIS)

    Story, T.

    2007-01-01

    In semiconductor spintronics the key materials issue concerns ferromagnetic semiconductors that would, in particular, permit an integration (in a single multilayer heterostructure) of standard electronic functions of semiconductors with magnetic memory function. Although classical semiconductor materials, such as Si or GaAs, are nonmagnetic, upon substitutional incorporation of magnetic ions (typically of a few atomic percents of Mn 2+ ions) and very heavy doping with conducting carriers (at the level of 10 20 - 10 21 cm -3 ) a ferromagnetic transition can be induced in such diluted magnetic semiconductors (also known as semimagnetic semiconductors). In the lecture the spectacular experimental observations of carrier concentration induced ferromagnetism will be discussed for three model semiconductor crystals. p - Ga 1-x Mn x As currently the most actively studied and most perspective ferromagnetic semiconductor of III-V group, in which ferromagnetism appears due to Mn ions providing both local magnetic moments and acting as acceptor centers. p - Sn 1-x Mn x Te and p - Ge 1-x Mn x Te classical diluted magnetic semiconductors of IV-VI group, in which paramagnet-ferromagnet and ferromagnet-spin glass transitions are found for very high hole concentration. n - Eu 1-x Gd x Te mixed magnetic crystals, in which the substitution of Gd 3+ ions for Eu 2+ ions creates very high electron concentration and transforms antiferromagnetic EuTe (insulating compound) into ferromagnetic n-type semiconductor alloy. For each of these materials systems the key physical features will be discussed concerning: local magnetic moments formation, magnetic phase diagram as a function of magnetic ions and carrier concentration as well as Curie temperature and magnetic anisotropy engineering. Various theoretical models proposed to explain the effect of carrier concentration induced ferromagnetism in semiconductors will be briefly discussed involving mean field approaches based on Zener and RKKY

  14. Investigating high zircon concentrations in the fine fraction of stream sediments draining the Pan-African Dahomeyan Terrane in Nigeria

    International Nuclear Information System (INIS)

    Key, Roger M.; Johnson, Christopher C.; Horstwood, Matthew S.A.; Lapworth, Dan J.; Knights, Katherine V.; Kemp, Simon J.; Watts, Michael; Gillespie, Martin; Adekanmi, Michael; Arisekola, Tunde

    2012-01-01

    Sixteen hundred stream sediments (<150 μm fraction) collected during regional geochemical surveys in central and SW Nigeria have high median and maximum concentrations of Zr that exceed corresponding Zr concentrations found in stream sediments collected from elsewhere in the World with similar bedrock geology. X-ray diffraction studies on a sub-set of the analysed stream sediments showed that Zr is predominantly found in detrital zircon grains. However, the main proximal source rocks (Pan-African ‘Older Granites’ of Nigeria and their Proterozoic migmatitic gneiss country rocks) are not enriched in zircon (or Zr). Nevertheless, U–Pb LA-ICP-MS dating with cathodoluminescence imaging on detrital zircons, both from stream sediment samples and underlying Pan-African ‘Older Granites’ confirms a local bedrock source for the stream sediment zircons. A combination of tropical/chemical weathering and continuous physical weathering, both by ‘wet season’ flash flooding and ‘dry season’ unidirectional winds are interpreted to have effectively broken down bedrock silicate minerals and removed much of the resultant clay phases, thereby increasing the Zr contents in stream sediments. The strong correlation between winnowing index (Th/Al) and Zr concentration across the study area support this interpretation. Therefore, ‘anomalous’ high values of Zr, as well as other elements concentrated in resistant ‘heavy’ minerals in Nigeria’s streams may not reflect proximal bedrock concentrations of these elements. This conclusion has important implications for using stream sediment chemistry as an exploration tool in Nigeria for primary metal deposits associated with heavy minerals.

  15. Central Colorado Assessment Project (CCAP)-Geochemical data for rock, sediment, soil, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; DeWitt, Ed H.; Klein, Terry L.

    2010-01-01

    This database was initiated, designed, and populated to collect and integrate geochemical data from central Colorado in order to facilitate geologic mapping, petrologic studies, mineral resource assessment, definition of geochemical baseline values and statistics, environmental impact assessment, and medical geology. The Microsoft Access database serves as a geochemical data warehouse in support of the Central Colorado Assessment Project (CCAP) and contains data tables describing historical and new quantitative and qualitative geochemical analyses determined by 70 analytical laboratory and field methods for 47,478 rock, sediment, soil, and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed either in the analytical laboratories of the USGS or by contract with commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects. In addition, geochemical data from 7,470 sediment and soil samples collected and analyzed under the Atomic Energy Commission National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program (henceforth called NURE) have been included in this database. In addition to data from 2,377 samples collected and analyzed under CCAP, this dataset includes archived geochemical data originally entered into the in-house Rock Analysis Storage System (RASS) database (used by the USGS from the mid-1960s through the late 1980s) and the in-house PLUTO database (used by the USGS from the mid-1970s through the mid-1990s). All of these data are maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB and from the NURE database were used to generate most of this dataset. In addition, USGS data that have been excluded previously from the NGDB because the data predate earliest USGS geochemical databases, or were once excluded for programmatic reasons

  16. grain size and heavy mineral analyses of two boreholes in recent

    African Journals Online (AJOL)

    user

    mineral composition and the grain sizes of the aquifer in the study areas. ... analysis of both wells show that mean, inclusive standard deviation, ..... colourless grains with rectangular outline. .... Nigeria; A Case Study of Onisha and Environ.

  17. Source rock indication from the heavy mineral weight percentages, central Tamil Nadu, India

    Digital Repository Service at National Institute of Oceanography (India)

    Rajamanickam, G.V.; Chandrasekaran, R.; Manickaraj, D.S.; Gujar, A.R.; Loveson, V.J.; Chaturvedi, S.K.; Chandrasekar, N.; Mahesh, R.

    From December 2003 to December 2005 beach sand samples have been collected at regular intervals. During this period the event of 26th December, 2004 tsunami enabled us to analyze the impact of the same in the beach sediments particularly heavy...

  18. Onshore heavy mineral placers of south Maharashtra, central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Ambre, N.V.; Mislankar, P.G.

    ) and are relatively more abundant in the berm and dune regions (supratidal/backshore zone) compared to beach (intertidal/ foreshore zone). Ilmenites are fresh, their shapes varies from euhedral to rounded and shows minor degree of alternation to sphene and leucoxene...

  19. Some aspects of the genesis of heavy mineral assemblages in Lower Proterozoic uranium-gold conglomerates

    International Nuclear Information System (INIS)

    Clemmey, H.

    1982-01-01

    Some genetic models for Lower Proterozoic gold- and uranium-bearing pyritic conglomerates favour a modified placer origin in which low levels of atmospheric oxygen are used to account for the survival of uraninite and pyrite. There are many difficulties with such models. New evidence concerning the genesis of the deposits is derived from a clast of ferric iron clay thought to represent a precursor sediment of the Witwatersrand Basin. Reworking of such clays and transport of a magnetite and ferric clay assemblage with subsequent sulphidation, could account for the porous pyrites, the absence of magnetite and the lack of hydraulic equivalence of the mineral grains in the conglomerates. The presence of oxygen, as indicated by the ferric iron clasts, would account for the evidence of mobility of uranium and of gold and would enhance their extraction from source rocks; particularly the release of gold from a precursor auriferous iron formation source. It is suggested that some aspects of the genesis of uranium deposits of the Witwatersrand and Elliott Lake may be similar to those of the Phanerozoic 'Roll Front' ores involving interaction between oxidizing uraniferous groundwaters and previously sulphidized and reduzate facies sediments. (author)

  20. Transparent heavy mineral distribution in the Bays of Jaigad, Ambwah, and Varvada, Ratnagiri District, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Rajamanickam, G.V.; Gujar, A.R.

    stream_size 11 stream_content_type text/plain stream_name J_Indian_Assoc_Sedimentol_14_43.pdf.txt stream_source_info J_Indian_Assoc_Sedimentol_14_43.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  1. Heavy minerals from the outer south-west continental shelf of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gujar, A.R.; Mislankar, P.G.; Wagle, B.G.

    stream_size 8 stream_content_type text/plain stream_name Giornale_Geol_52_91.pdf.txt stream_source_info Giornale_Geol_52_91.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  2. Impact of offshore placer mining experiments (PLAMEX) on the sediment size and heavy minerals

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.; Fernandes, D.

    Two offshore placer mining experiments (PLAMEX) were conducted using submersible pumps specially designed by Central Mechanical Engineering Research Institute (CMERI), Durgapur (India) at 8 m water depth in Kalbadevi Bay (PLAMEX-I), Ratnagiri...

  3. Seasonal variations in heavy mineral placer sand from Kalbadevi Bay, Ratnagiri, Maharashtra

    Digital Repository Service at National Institute of Oceanography (India)

    Valsangkar, A.B.

    spaced at ~1.5 km apart (Fig. 1). More details are given in Valsangkar (2005). Beach samples were obtained by push cores from the different beach environment that included dune, berm, hide tide (HT), mid tide (MT) and low tide (LT) area. The samples...) decreased to 12 % during post-monsoon season. Increase of sand content with depth in bern environment is therefore considered related to deposition due to wave and current action. May, 2K4; BP-02 0 20 40 60 80 100 120 Dune Berm HT MT LT Sand % 0-5 5...

  4. Understanding heavy mineral dynamics using magnetic fingerprinting technique: A case study of North Maharashtra Coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Badesab, F.K.; Iyer, S.D.; Gujar, A; Naik, D.K.; Gaonkar, S.S.; Luis, R.A.A; Shirodkar, P.; Naik, Smita

    Environmental magnetic and grain size measurements were carried out on sand samples collected from nine sand pits along a 20-km coastal stretch of Arnala Beach, North Maharashtra, India. This study sets out to identify the potential heavy (magnetite...

  5. YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductor deposited onto non-magnetic ternary alloy NiCrW RABiTS tape by in situ pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Tomov, R I; Kursumovic, A; Majoros, M; Glowacki, B A; Evetts, J E; Tuissi, A; Villa, E; Zamboni, M; Sun, Y; Toenies, S; Weber, H W

    2003-01-01

    Pulsed laser deposition of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO)/buffer (Y{sub 2}O{sub 3}, YSZ, CeO{sub 2}) heterostructures have been performed in situ onto recently developed non-magnetic oxygenation resistant NiCrW tape. The influence of the critical processing parameters on texture development are investigated and the issues involved in NiO formation and relation to the substrate surface quality are discussed. The roles of Ni poisoning YBCO as well as local cation disorder are considered as possible current limiting factors. X-ray diffraction has been used for macro-texture evaluation. Both buffers and YBCO layers show good biaxial alignment with {omega} and {phi} scans having best YBCO FWHM values of 4.0 deg. and 6.5 deg. respectively. A comparison is made with results achieved on industrial Ni{sub 50}Fe{sub 50} tape. The film morphology has been characterized using atomic force microscopy and scanning electron microscopy. The cation disorder has been studied by Raman spectroscopy. Critical temperatures of 90 K ({delta}T{sub c}=5 K) have been measured. Direct transport as well as magnetic measurements shows the critical current density J{sub c} is 0.2 MA/cm{sup 2} in self-field at liquid nitrogen temperatures.

  6. Collapsed tetragonal phase as a strongly covalent and fully nonmagnetic state: Persistent magnetism with interlayer As-As bond formation in Rh-doped Ca0 .8Sr0 .2Fe2As2

    Science.gov (United States)

    Zhao, K.; Glasbrenner, J. K.; Gretarsson, H.; Schmitz, D.; Bednarcik, J.; Etter, M.; Sun, J. P.; Manna, R. S.; Al-Zein, A.; Lafuerza, S.; Scherer, W.; Cheng, J. G.; Gegenwart, P.

    2018-02-01

    A well-known feature of the CaFe2As2 -based superconductors is the pressure-induced collapsed tetragonal phase that is commonly ascribed to the formation of an interlayer As-As bond. Using detailed x-ray scattering and spectroscopy, we find that Rh-doped Ca0.8Sr0.2Fe2As2 does not undergo a first-order phase transition and that local Fe moments persist despite the formation of interlayer As-As bonds. Our density functional theory calculations reveal that the Fe-As bond geometry is critical for stabilizing magnetism and the pressure-induced drop in the c lattice parameter observed in pure CaFe2As2 is mostly due to a constriction within the FeAs planes. The collapsed tetragonal phase emerges when covalent bonding of strongly hybridized Fe 3 d and As 4 p states completely wins out over their exchange splitting. Thus the collapsed tetragonal phase is properly understood as a strong covalent phase that is fully nonmagnetic with the As-As bond forming as a by-product.

  7. An integrated geochemical, geophysical and mineralogical study of river sediments in alpine area and soil samples near steel plant, in Austria

    Science.gov (United States)

    Irfan, M. I.; Meisel, T.

    2012-04-01

    Concentration of nickel and chromium in any part of the ecosystem is important for environmental concerns in particular human health due to the reason that some species of them can cause health problem e.g. dermatitis and cancer. Sediment samples collected form a river Vordernberger Bach (Leoben, Austria) in an alpine region and soil samples collected in an area adjacent to steel production unit in same narrow valley were investigated. In previous studies a correlation between magnetic susceptibility values and concentration of nickel and chromium showed that a magnetic susceptibility meter can be used to point out the contaminated areas as in-situ device. The purpose of the whole study is to understand the real (point or diffuse, anthropogenic or geogenic) sources of contamination of soils, water and river sediments through heavy metal deposition. Unseparated, magnetic and non-magnetic fractions of soil samples were investigated for geochemical and mineralogical aspects with XRF, ICP-MS, EMPA, Multi-Functional Kappabridge (MFK1) and laser ablation coupled with ICP-MS. Mineralogical study of sediment samples for several sampling points with higher Ni and Cr content was performed. Sediment samples were sieved below 1.4 mm and then a concentrate of heavy minerals was prepared in the field through panning. Concentrated heavy minerals were then subjected for heavy liquid separation in the laboratory. Separated magnetic and non-magnetic fractions below 0.71/0.1 mm and density greater than 2.9 g/cm3 were selected for mineralogical investigation. The abundance of typical anthropogenic particles, e.g., spherical, tinder, roasted ores, iron and steel mill slag was observed under the microscope. Magnetite (mostly anthropogenic), maghemite, chromspinel, chromite (type I & II), (Ca,Al)-ferrite, wustite, apatite (anthropogenic), olivine mixed crystals, calcium silicate and spinel (anthropogenic) are found in magnetic fraction. Non-magnetic fractions contain hematite, siderite

  8. Ultra flat ideal concentrators of high concentration

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Julio [IST, Physics Dept., Lisboa (Portugal); INETI-DER, Lisboa (Portugal); Collares-Pereira, Manuel [INETI-DER, Lisboa (Portugal)

    2000-07-01

    A new method for the design of nonimaging devices is presented. Its application to the design of ultra flat compact concentrators is analysed. These new concentrators are based on a combination of two stages: the first one is composed of a large number of small structures placed side by side and the second one is a very compact single device concentrating the radiation to the limit. These devices are ideal for 2D. These compact designs are much more compact than the traditional ones like lens-mirror combinations or parabolic primaries with nonimaging secondaries. Besides, they can be designed for any acceptance angle, while the traditional ones are limited to small acceptance angles. (Author)

  9. Highly concentrating Fresnel lenses

    International Nuclear Information System (INIS)

    Kritchman, E.M.; Friesem, A.A.; Yekutieli, G.

    1979-01-01

    A new type of concave Fresnel lens capable of concentrating solar radiation very near the ultimate concentration limit is considered. The differential equations that describe the lens are solved to provide computed solutions which are then checked by ray tracing techniques. The performance (efficiency and concentration) of the lens is investigated and compared to that of a flat Fresnel lens, showing that the new lens is preferable for concentrating solar radiation. (author)

  10. Solar cell concentrating system

    International Nuclear Information System (INIS)

    Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

    1986-11-01

    This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

  11. Rheology of concentrated biomass

    Science.gov (United States)

    J.R. Samaniuk; J. Wang; T.W. Root; C.T. Scott; D.J. Klingenberg

    2011-01-01

    Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained...

  12. Underscreening in concentrated electrolytes.

    Science.gov (United States)

    Lee, Alpha A; Perez-Martinez, Carla S; Smith, Alexander M; Perkin, Susan

    2017-07-01

    Screening of a surface charge by an electrolyte and the resulting interaction energy between charged objects is of fundamental importance in scenarios from bio-molecular interactions to energy storage. The conventional wisdom is that the interaction energy decays exponentially with object separation and the decay length is a decreasing function of ion concentration; the interaction is thus negligible in a concentrated electrolyte. Contrary to this conventional wisdom, we have shown by surface force measurements that the decay length is an increasing function of ion concentration and Bjerrum length for concentrated electrolytes. In this paper we report surface force measurements to test directly the scaling of the screening length with Bjerrum length. Furthermore, we identify a relationship between the concentration dependence of this screening length and empirical measurements of activity coefficient and differential capacitance. The dependence of the screening length on the ion concentration and the Bjerrum length can be explained by a simple scaling conjecture based on the physical intuition that solvent molecules, rather than ions, are charge carriers in a concentrated electrolyte.

  13. concentration on spin-dependent resonant tunnelling in InAs/Ga1 ...

    Indian Academy of Sciences (India)

    Cent percentage polarization can be obtained in this strained non-magnetic double-barrier ... Keywords. Spin–orbit interaction; barrier transparency; polarization efficiency; tunnelling lifetime. 1. Introduction ..... Figure 6. Tunnelling lifetime vs.

  14. Concentrating photovoltaic solar panel

    Science.gov (United States)

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  15. Photovoltaic static concentrator analysis

    Science.gov (United States)

    Almonacid, G.; Luque, A.; Molledo, A. G.

    1984-12-01

    Ray tracing is the basis of the present analysis of truncated bifacial compound parabolic concentrators filled with a dielectric substance, which are of interest in photovoltaic applications where the bifacial cells allow higher static concentrations to be achieved. Among the figures of merit for this type of concentrator, the directional intercept factor plays a major role and is defined as the ratio of the power of the collector to that at the entry aperture, in a lossless concentrator illuminated by light arriving from a given direction. A procedure for measuring outdoor, full size panels has been developed, and a correction method for avoiding the effect of unwanted diffuse radiation during the measurements is presented.

  16. CMAQ predicted concentration files

    Data.gov (United States)

    U.S. Environmental Protection Agency — model predicted concentrations. This dataset is associated with the following publication: Muñiz-Unamunzaga, M., R. Borge, G. Sarwar, B. Gantt, D. de la Paz, C....

  17. Vaginal oxytetracycline concentrations.

    Science.gov (United States)

    Thin, R N; Al Rawi, Z H; Simmons, P D; Treharne, J; Tabaqchali, S

    1979-01-01

    Although tetracycline preparations are widely used in departments of genitourinary medicine, or sexually transmitted diseases clinics, little is known of the concentrations of these preparations in genital secretions. For this reason a microbiological method was used for estimating oxytetracycline concentrations in vaginal secretions. These concentrations varied from 0.6 to 6.5 microgram/ml in 19 women who had had sexual contact with a man with non-specific urethritis and who were taking oxytetracycline dihydrate 250 mg four times daily. They were well in excess of the minimum inhibitory concentration of oxytetracycline (0.2 microgram/ml) for the strains of Chlamydia trachomatis isolated from the patients with positive culture results. Thus, oxytetracycline 250 mg four times daily appears to be a satisfactory regimen for the treatment of chlamydial genital infection in women. PMID:509190

  18. Concentrations of Indicator Organisms

    Data.gov (United States)

    U.S. Environmental Protection Agency — It is a compilation of organism concentrations of 16 sampling events conducted between July 2015 and February 2016. It also includes statistical analysis such as...

  19. Concentrated Differential Privacy

    OpenAIRE

    Dwork, Cynthia; Rothblum, Guy N.

    2016-01-01

    We introduce Concentrated Differential Privacy, a relaxation of Differential Privacy enjoying better accuracy than both pure differential privacy and its popular "(epsilon,delta)" relaxation without compromising on cumulative privacy loss over multiple computations.

  20. Industrialisation et concentration urbaine

    OpenAIRE

    Kamal , Abdelhak

    2010-01-01

    The aim of this thesis is to analyze the determinants of the urban concentration and their effect at different levels of development. The empirical analysis focuses on the developing countries over the period 1950-2000 grouped by level of per capita income. The results confirm the existence of specific trajectories of urbanization rate and urban primacy which differs meaningfully according to the stage of development considered. Certain factors encourage urbanization and its concentration in ...

  1. Solar concentrators. Concentradores solares

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, R.; Valdes, A.; Lopez, S.

    1981-06-01

    This paper presents different types of geometries used in concentrators. Some comments are made on the theoretical and experimental analysis necessary to evaluate the geometries and on the type of laboratory equipment needed to obtain experimental data. At the end of the report a description of how to build parabolic trough mirrors is made. The experience gained by the authors, who have been working in this subject for the past five years, is summarized, showing some of the problems related with such concentrators.

  2. Concentration factors for fish

    International Nuclear Information System (INIS)

    Feldt, W.; Lauer, R.; Melzer, M.; Siebert, W.

    1978-01-01

    Concentration factors are defined as operators allowing to calculate the specific activity of fish meat from a given concentration of an element in the water. This parameter depends among others from the content of stable isotopes and homologues in the different waters. If this parameter is reasonably to be used for model calculations it must be referred to water with all of its content substances, these calculations also being based on this type of 'water'. (orig.) [de

  3. FK concentrator outdoor measurements

    OpenAIRE

    Hernández Sanz, Maikel; Vilaplana, J., J.; Benitez Gimenez, Pablo; Mohedano,, Rubén; Zamora Herranz, Pablo; Miñano Dominguez, Juan Carlos; Mendes Lopes, Joao

    2013-01-01

    The FK is a two-stage optical concentrator for CPV, composed by a Fresnel lens working as POE and a refractive element working as SOE. Both elements perform Köhler integration, for uniform irradiance purposes. The FK has demonstrated that compares very well with other Fresnel-based concentrator optics. Recent on-sun measurements carried out on an FK mono-module prototype have already shown outstanding results, achieving electrical efficiencies over 34%. Further optimization of optical design ...

  4. Mn concentration and quantum size effects on spin-polarized transport through CdMnTe based magnetic resonant tunneling diode.

    Science.gov (United States)

    Mnasri, S; Abdi-Ben Nasrallahl, S; Sfina, N; Lazzari, J L; Saïd, M

    2012-11-01

    Theoretical studies on spin-dependent transport in magnetic tunneling diodes with giant Zeeman splitting of the valence band are carried out. The studied structure consists of two nonmagnetic layers CdMgTe separated by a diluted magnetic semiconductor barrier CdMnTe, the hole is surrounded by two p-doped CdTe layers. Based on the parabolic valence band effective mass approximation and the transfer matrix method, the magnetization and the current densities for holes with spin-up and spin-down are studied in terms of the Mn concentration, the well and barrier thicknesses as well as the voltage. It is found that, the current densities depend strongly on these parameters and by choosing suitable values; this structure can be a good spin filter. Such behaviors are originated from the enhancement and suppression in the spin-dependent resonant states.

  5. Photovoltaic solar concentrator

    Science.gov (United States)

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  6. Concentrated loads on concrete

    DEFF Research Database (Denmark)

    Lorenzen, Karen Grøndahl; Nielsen, Mogens Peter

    1997-01-01

    This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas are devel......This report deals with concentrated loads on concrete.A new upper bound solution in the axisymmetrical case of a point load in the center of the end face of a cylinder is developed.Based on previous work dealing with failure mechanisms and upper bound solutions, new approximate formulas...

  7. RX: a nonimaging concentrator.

    Science.gov (United States)

    Miñano, J C; Benítez, P; González, J C

    1995-05-01

    A detailed description of the design procedure for a new concentrator, RX, and some examples of it's use are given. The method of design is basically the same as that used in the design of two other concentrators: the RR and the XR [Appl. Opt. 31, 3051 (1992)]. The RX is ideal in two-dimensional geometry. The performance of the rotational RX is good when the average angular spread of the input bundle is small: up to 95% of the power of the input bundle can be transferred to the output bundle (with the assumption of a constant radiance for the rays of the input bundle).

  8. Parabolic solar concentrator

    Science.gov (United States)

    Tecpoyotl-Torres, M.; Campos-Alvarez, J.; Tellez-Alanis, F.; Sánchez-Mondragón, J.

    2006-08-01

    In this work we present the basis of the solar concentrator design, which has is located at Temixco, Morelos, Mexico. For this purpose, this place is ideal due to its geographic and climatic conditions, and in addition, because it accounts with the greatest constant illumination in Mexico. For the construction of the concentrator we use a recycled parabolic plate of a telecommunications satellite dish (NEC). This plate was totally covered with Aluminum. The opening diameter is of 332 cm, the focal length is of 83 cm and the opening angle is of 90°. The geometry of the plate guaranties that the incident beams, will be collected at the focus. The mechanical treatment of the plate produces an average reflectance of 75% in the visible region of the solar spectrum, and of 92% for wavelengths up to 3μm in the infrared region. We obtain up to 2000°C of temperature concentration with this setup. The reflectance can be greatly improved, but did not consider it as typical practical use. The energy obtained can be applied to conditions that require of those high calorific energies. In order to optimize the operation of the concentrator we use a control circuit designed to track the apparent sun position.

  9. A Microfluidic Cell Concentrator

    Science.gov (United States)

    Warrick, Jay; Casavant, Ben; Frisk, Megan; Beebe, David

    2010-01-01

    Cell concentration via centrifugation is a ubiquitous step in many cell culture procedures. At the macroscale, centrifugation suffers from a number of limitations particularly when dealing with small numbers of cells (e.g., less than 50,000). On the other hand, typical microscale methods for cell concentration can affect cell physiology and bias readouts of cell behavior and function. In this paper, we present a microfluidic concentrator device that utilizes the effects of gravity to allow cells to gently settle out of a suspension into a collection region without the use of specific adhesion ligands. Dimensional analysis was performed to compare different device designs and was verified with flow modeling to optimize operational parameters. We are able to concentrate low-density cell suspensions in a microfluidic chamber, achieving a cell loss of only 1.1 ± 0.6% (SD, n=7) with no observed loss during a subsequent cell staining protocol which incorporates ~36 complete device volume replacements. This method provides a much needed interface between rare cell samples and microfluidic culture assays. PMID:20843010

  10. Aluminum concentration in hydrangeas

    International Nuclear Information System (INIS)

    Yanagawa, M.; Haruyama, Y.; Saito, M.

    2008-01-01

    We have been trying to measure concentration of aluminum in Ajisai, Hydrangea macrophylla for these days. But due to bad luck, we have encountered detector trouble for two years in a low. Thus, we have few data to analyze and obtained quite limited results. (author)

  11. Theory of Concentrated Vortices

    DEFF Research Database (Denmark)

    Alekseenko, Sergey; Kuibin, Pavel; Okulov, Valery

    This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have describ...

  12. Scattering Solar Thermal Concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel C. [Pennsylvania State Univ., State College, PA (United States)

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  13. Concentric Split Flow Filter

    Science.gov (United States)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  14. Tritium concentration monitor

    International Nuclear Information System (INIS)

    Shono, Kosuke.

    1991-01-01

    A device for measuring the concentration of tritium in gaseous wastes in a power plant and a nuclear fuel reprocessing plant is reduced in the size and improved in performance. The device of the present invention pressurizes a sampling gas and cools it to a dew point. Water content in the sampling gas cooled to the dew point is condensated and recovered to a fine tube-like water content recovering container. The concentration of the recovered condensates is measured by a tritium density analyzer. With such procedures, since the specimen is pressurized, the dew point can be elevated. Accordingly, the size of the cooling device can be decreased, enabling to contribute to the reduction of the size of the entire device. Further, since the water content recovering device is formed as a fine tube, the area of contact between the specimen gas and the liquid condensated water can be reduced. Accordingly, evaporation of the liquid condensates can be prevented. (I.S.)

  15. Zirconia concentrate chlorination

    International Nuclear Information System (INIS)

    Costa, N.G.; Albuquerque Brocchi, E. de

    1990-01-01

    Chlorination experiments were conducted in order to study the kinetics of gasification of the zirconium oxide present in the zirconia concentrate. The variables studied are temperature (1173 to 1373 K), percentage of reducing agent (12 to 36%) and porosity (22 to 30%). The results indicated a greater influence of temperature and percentage of reducing agent as well as allowed the conclusion that a balance between the levels of these variables is an important factor in the appropriate chlorination conditions. (author)

  16. Thermodynamically efficient solar concentrators

    Science.gov (United States)

    Winston, Roland

    2012-10-01

    Non-imaging Optics is the theory of thermodynamically efficient optics and as such depends more on thermodynamics than on optics. Hence in this paper a condition for the "best" design is proposed based on purely thermodynamic arguments, which we believe has profound consequences for design of thermal and even photovoltaic systems. This new way of looking at the problem of efficient concentration depends on probabilities, the ingredients of entropy and information theory while "optics" in the conventional sense recedes into the background.

  17. Electrolyte Concentrates Treat Dehydration

    Science.gov (United States)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  18. Chlorination of zirconyte concentrate

    International Nuclear Information System (INIS)

    Costa, N.G.

    1988-01-01

    Chlorination experiments with zirconyte concentrate were carried out in order to study the effects of temperature, percentage of reducing agent and porosity on the gasification of ZrO 2 for 10 and 20 minutes of reaction. Factorial analysis was applied and the results indicated that temperature and percentage of reducing agent were the two only variables effecting the ZrO 2 gasification. (author) [pt

  19. Optimization of Mineral Separator for Recovery of Total Heavy Minerals of Bay of Bengal using Central Composite Design

    Science.gov (United States)

    Routray, Sunita; Swain, Ranjita; Rao, Raghupatruni Bhima

    2017-04-01

    The present study is aimed at investigating the optimization of a mineral separator for processing of beach sand minerals of Bay of Bengal along Ganjam-Rushikulya coast. The central composite design matrix and response surface methodology were applied in designing the experiments to evaluate the interactive effects of the three most important operating variables, such as feed quantity, wash water rate and Shake amplitude of the deck. The predicted values were found to be in good agreement with the experimental values (R2 = 0.97 for grade and 0.98 for recovery). To understand the impact of each variable, three dimensional (3D) plots were also developed for the estimated responses.

  20. Heavy mineral distribution in the surficial sediments from the eastern continental margin of India and their implications on palaeoenvironment

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Gujar, A.R.

    and titanite), garnet, sillimanite, hornblende, hypersthene, tourmaline, zircon, monazite, biotite, kyanite and staurolite are present in variable proportions. Hydraulic fractionation (size, shape, density) and selective chemical decompositiom of unstable...

  1. Heavy mineral sorting and distributions within massive sandstone divisions (Bouma A divisions) of Brushy Canyon Formation turbidites

    Science.gov (United States)

    Motanated, K.; Tice, M. M.

    2009-12-01

    KANNIPA MOTANATED and MICHAEL M. TICE Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843-3115, USA Sediment sorting data are commonly used for interpreting depositional environments, analyzing mechanisms of deposition and transportation, and inferring relative transport distance of sediments. Typically, sorting in sandstones is estimated by point-counting thin sections which is a time consuming procedure and requires cutting sections of rock samples. We demonstrate a new technique for quantifying sediment sorting using element distribution maps obtained by x-ray fluorescence microscopy. We show that hydraulic sorting of Zr- and Ti- bearing grains (probably zircon and rutile, respectively) results in characteristic vertical profiles of Zr and Ti abundances within the Bouma A divisions of turbidites of the Brushy Canyon Formation, Delaware Basin, southern New Mexico. Zr- and Ti- bearing grains decrease in abundance and diameter from bases to tops of A divisions in every sample examined in this study. These results contrast with previous observations which suggest that grading in Brushy Canyon Formation structureless sandstones is absent or rare. The data support turbiditic interpretations of these rocks against traction current interpretations which rely on the lack of textural grading. Grading is reflected in vertical profiles of Ti/Al, Zr/Al and Zr/Ti ratios, which each decrease upward. These compositional variations could potentially be used as geochemical proxies for physical sorting, and might be useful for inferring depositional processes and relative transport distances.

  2. Magnetic anomalies and their possible relation with heavy mineral placers and basement configuration in Mirya bay, Konkan coast, Maharashtra, India

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.

    ) N-S trending high amplitude and long wavelength anomalies (250-350 nT, about 500-700 m) approximately on a line joining the Mirya Head with the Bhagvati Fort, Maharashtra, India and extending 3 km offshore, and (2) low amplitude and medium to short...

  3. Concentrated Solar Thermoelectric Power

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Gang [MIT; Ren, Zhifeng [University of Houston

    2015-07-09

    The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accurate measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.

  4. Censored correlated cytokine concentrations

    DEFF Research Database (Denmark)

    Andersen, Andreas; Benn, Christine Stabell; Jørgensen, Mathias J

    2013-01-01

    ) can be used to describe the relative concentration between two cytokines, and the GMR ratio (GMRR) can be used to compare two groups. The problem is how to estimate GMRRs from censored distributions.We evaluated methods, including simple deletion and substitution, in simulated and real data. One...... stacking method that uses clustered variance-covariance estimation allowing homogeneous (Stackc) or inhomogeneous (Stackh) variances. We compare it with direct estimation of the bivariate Tobit likelihood function (Bitobit) and multiple imputation. We assess sensitivity to inhomogeneity and non...

  5. Concentrating Solar Power Systems

    Science.gov (United States)

    Pitz-Paal, R.

    2017-07-01

    Development of Concentrating Solar Power Systems has started about 40 years ago. A first commercial implementation was performed between 1985 and 1991 in California. However, a drop in gas prices caused a longer period without further deployment. It was overcome in 2007 when new incentive schemes for renewables in Spain and the US enabled a commercial restart. In 2016, almost 100 commercial CSP plants with more than 5GW are installed worldwide. This paper describes the physical background of CSP technology, its technical characteristics and concepts. Furthermore, it discusses system performances, cost structures and the expected advancement.

  6. Uranium concentration in fossils

    International Nuclear Information System (INIS)

    Okano, J.; Uyeda, C.

    1988-01-01

    Recently it is known that fossil bones tend to accumulate uranium. The uranium concentration, C u in fossils has been measured so far by γ ray spectroscopy or by fission track method. The authors applied secondary ion mass spectrometry, SIMS, to detect the uranium in fossil samples. The purpose of this work is to investigate the possibility of semi-quantitative analyses of uranium in fossils, and to study the correlation between C u and the age of fossil bones. The further purpose of this work is to apply SIMS to measure the distribution of C u in fossil teeth

  7. Theory of Concentrated Vortices

    DEFF Research Database (Denmark)

    Alekseenko, Sergey; Kuibin, Pavel; Okulov, Valery

    This book presents comprehensive and authoritative coverage of the wide field of concentrated vortices observed in nature and technique. The methods for research of their kinematics and dynamics are considered. Special attention is paid to the flows with helical symmetry. The authors have describ...... models of vortex structures used for interpretation of experimental data which serve as a ground for development of theoretical and numerical approaches to vortex investigation. Achievements in the fields of stability analysis, waves on vortices and vortex breakdown are also presented....

  8. Complex concentrate pretreatment

    International Nuclear Information System (INIS)

    Lokken, R.O.; Scheele, R.D.; Strachan, D.M.; Toste, A.P.

    1991-03-01

    After removal of the transuranics (TRU) by the TRUEX process, complex concentrate waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory, is to support a future decision to grout the complexant waste without destruction of the organic contents. It has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than previously. None of the organics found in the waste have been found on the EPA hazardous chemicals list. Two potential problems with the processing of the complex concentrate wastes were identified during the use of the TRUEX process on samples of several milliliters. One was the amount of foam that is generated during acid addition to the alkaline waste. Some of this foam appears to be of a waxy nature but does redissolve when the waste is strongly acid. The second potential problem is that noticeable amounts of NO x gases are generated. No quantitative measure of the NO x gas generation was made. The problem relates to processing the waste in B-plant where there are no facilities to handle NO x gases. 5 refs., 4 figs., 4 tabs

  9. Dual temperature concentration system

    International Nuclear Information System (INIS)

    Spevack, J.S.

    1975-01-01

    In a dual temperature isotope exchange system--exemplified by exchange of deuterium and protium between water and hydrogen sulfide gas in hot and cold towers, in which the feed stream (water) containing the desired isotope is passed through a pair of towers maintained at different temperatures wherein it effects isotope exchange with countercurrently circulated auxiliary fluid (H 2 S) and is impoverished in said isotope and then disposed of, e.g. discharged to waste,--the flow of isotope enriched auxiliary fluid between said towers (hot H 2 S saturated with water vapor) is divided and a part thereof is adjusted in its temperature (to cold tower conditions) and then passed to the auxiliary fluid impoverishing (cold) tower, while the remainder of the divided flow of such enriched auxiliary fluid is passed through a subsequent isotope concentration treatment to produce a product more highly enriched in the desired isotope and wherein it is also adjusted in its temperature and is impoverished in said isotope during said subsequent treatment before it is delivered to the said auxiliary fluid impoverishing (cold) tower. Certain provisions are made for returning to the hot tower liquid carried as vapor by the remainder of the divided flow to the subsequent isotope concentration treatment, for recovering sensible and latent heat, and for reducing passage of auxiliary fluid to waste

  10. Luminescent solar concentrator

    Directory of Open Access Journals (Sweden)

    Tugce Tosun

    2015-07-01

    Full Text Available Luminescent solar concentrator (LSC is a device that has luminescent molecules embedding or topping polymeric or glass waveguide to generate electricity from sunlight with a photovoltaic cell attachment. LSCs can be employed both in small and large scale projects, independent on the direction or angle of the surface with respect to the sun, promising more freedom for integration in urban environments compared to the traditional PV systems. The aim of the SEB&C PDEng project is to investigate the applicability of this innovative technology in the built environment and to bridge the gap of knowledge linking societal, design and technological aspects. The final goal is to exhibit potential application concepts of LSC developed by co-creative methods at SPARK campus which is a hub for open innovation in built environment. Necessity of a paradigm shift towards sustainable and smart cities came into being due to the significant increase in energy demand of the buildings. The challenge is to increase renewable sources in the energy mix while designing aesthetic environments. Thus, building integrated renewable energy technologies represent a great opportunity to help overcome this current challenge. Smart energy, energy efficiency and use of renewable sources are key aspects to be considered nowadays and many innovative technologies need further exploitation to be commercially viable, such as luminescent solar concentrator.

  11. Pushing concentration of stationary solar concentrators to the limit.

    Science.gov (United States)

    Winston, Roland; Zhang, Weiya

    2010-04-26

    We give the theoretical limit of concentration allowed by nonimaging optics for stationary solar concentrators after reviewing sun- earth geometry in direction cosine space. We then discuss the design principles that we follow to approach the maximum concentration along with examples including a hollow CPC trough, a dielectric CPC trough, and a 3D dielectric stationary solar concentrator which concentrates sun light four times (4x), eight hours per day year around.

  12. Plasma concentrations of misonidazole

    Energy Technology Data Exchange (ETDEWEB)

    Notter, G; Rylander, U; Turesson, I

    1980-10-01

    The plasma concentrations of misonidazole doses between 0.6 and 2.0 g/m/sup 2/ were analyzed in respect to the variation within the same patient and between different patients. Peak plasma levels were observed after 2 hours. The mean plasma levels of misonidazole only at 3 hours were 23.8, 47.0 and 76.5 ..mu..g/ml after misonidazole doses of 0.6, 1.2 g/m/sup 2/, respectively. The half-life of misonidazole only was found to be 8.2 hours for women and 10.5 for men. Good linearity between plasma levels and drug doses was observed after administration of different single doses to the same patient within the dose range 0.6 to 2.0 g/m/sup 2/.

  13. Stress concentration at notches

    CERN Document Server

    Savruk, Mykhaylo P

    2017-01-01

    This book compiles solutions of linear theory of elasticity problems for isotropic and anisotropic bodies with sharp and rounded notches. It contains an overview of established and recent achievements, and presents the authors’ original solutions in the field considered with extensive discussion. The volume demonstrates through numerous, useful examples the effectiveness of singular integral equations for obtaining exact solutions of boundary problems of the theory of elasticity for bodies with cracks and notches. Incorporating analytical and numerical solutions of the problems of stress concentrations in solid bodies with crack-like defects, this volume is ideal for scientists and PhD students dealing with the problems of theory of elasticity and fracture mechanics. Stands as a modern and extensive compendium of solutions to the problems of linear theory of elasticity of isotropic and anisotropic bodies with sharp and rounded notches; Adopts a highly reader-friendly layout of tables, charts, approximation ...

  14. Concentration solar thermal power

    International Nuclear Information System (INIS)

    Livet, F.

    2011-01-01

    As the production of electricity by concentration solar power (CSP) installations is said to be a source of energy for the future, the author discusses past experiments (notably the French Thermis project), and the different techniques which are currently being used. He indicates the regions which appear to be the most appropriate for this technique. He presents the three main techniques: parabolic cylinder, tower, and Stirling cycle installations. He discusses the issue of intermittency. He proposes an assessment of prices and of their evolution, and indicates the investments made in different installations (in Italy, Spain, Germany and Portugal). He comments the case of hybrid installations (sun and gas), evokes the Desertec project proposed by the German industry which comprises a set of hybrid installations. He notices that there is no significant technological evolution for this process

  15. Concentrating solar thermal power.

    Science.gov (United States)

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept.

  16. Preparation of selective molybdenum concentrate from collective coppermolybdenum concentrate

    Directory of Open Access Journals (Sweden)

    N. Tusupbaev

    2016-06-01

    Full Text Available The paper considers possibilities of selective separation of the concentrate of copper and molybdenum from a collective copper-molybdenum concentrate of Aktogay deposit using regrinding and conventional flotation reagents. In the case of conventional flotoreagents, the content of molybdenum in a molybdenum concentrate was 8.0% at extraction effectiveness 83.12%. At 27.96% extraction degree of copper, it’s content in the concentrate equaled to 21.3%. After regrinding, molybdenum content in the concentrate was 24.0% at the extraction effectiveness 59.63%, and copper content in the concentrate was 21.9% at the recovery of 61.23%. Thus, the regrinding of a collective copper-molybdenum concentrate resulted in an increase in the content of molybdenum in molybdenum concentrate by 16%, and the copper concentration increased by 0.6%.

  17. Workplace Concentration of Immigrants

    Science.gov (United States)

    Andersson, Fredrik; García-Pérez, Mónica; Haltiwanger, John; McCue, Kristin; Sanders, Seth

    2014-01-01

    Casual observation suggests that in most U.S. urban labor markets, immigrants have more immigrant coworkers than native-born workers do. While seeming obvious, this excess tendency to work together has not been precisely measured, nor have its sources been quantified. Using matched employer–employee data from the U.S. Census Bureau Longitudinal Employer-Household Dynamics (LEHD) database on a set of metropolitan statistical areas (MSAs) with substantial immigrant populations, we find that, on average, 37% of an immigrant’s coworkers are themselves immigrants; in contrast, only 14% of a native-born worker’s coworkers are immigrants. We decompose this difference into the probability of working with compatriots versus with immigrants from other source countries. Using human capital, employer, and location characteristics, we narrow the mechanisms that might explain immigrant concentration. We find that industry, language, and residential segregation collectively explain almost all the excess tendency to work with immigrants from other source countries, but they have limited power to explain work with compatriots. This large unexplained compatriot component suggests an important role for unmeasured country-specific factors, such as social networks. PMID:25425452

  18. A preliminary combined geochemical and rock-magnetic study of tailings of non-magnetic ores from Tlalpujahua-El Oro mining districts, Michoacán and Estado de México States

    Science.gov (United States)

    Morales, J.; Hernández-Bernal, M.; Corona-Chávez, P.

    2013-05-01

    Mining activities in Mexico have been continuously developed since 1550. Since then several thousands of million tons of waste produced as a result of the mining activity have been accumulated and scattered throughout the territory. These wastes can contain minerals with potentially toxic elements (PTEs) such as Cr, As, Cd, Cu, Pb, Zn, which show a distribution and mobility in the environment according to the chemical species in which are hosted. The Tlalpujahua - El Oro mining district (TOMD) concentrates an impressive number of mines and historical tailings. Due to their in-slope hydrographic position, the mining activities increase the risk of generating anthropogenic effluent that could contribute with a certain amount of mine-water with high contents of PTEs. Although magnetic methods have been widely applied to pollution studies of regions with high anthropogenic impact, its application to tailings is scarce in spite of the several studies that document the environmental effects as a result of the mining waste. We present the results obtained by combined geochemical and rock-magnetic studies in these tailings. Similarly to the traditional EPTs vs SiO2 diagrams, EPTs vs Fe show good linear (inverse) correlation with most of these health-risk elements. Fe concentrations determined magnetically from room-temperature susceptibility measurements agrees with those obtained by traditionally geochemical methods.

  19. Magnetic surveys of the continental shelf off Visakhapatnam

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Murthy, K.S.R.

    shelf. Quantitative estimates made for the anomalies over the inner shelf using the graphical method and by computing the analytical signal suggest the existence of a fault in the nearshore region and a possible zone of heavy mineral concentration off...

  20. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  1. Membrane distillation for milk concentration

    NARCIS (Netherlands)

    Moejes, S.N.; Romero Guzman, Maria; Hanemaaijer, J.H.; Barrera, K.H.; Feenstra, L.; Boxtel, van A.J.B.

    2015-01-01

    Membrane distillation is an emerging technology to concentrate liquid products while producing high quality water as permeate. Application for desalination has been studied extensively the past years, but membrane distillation has also potential to produce concentrated food products like

  2. Concentrating on caustic

    International Nuclear Information System (INIS)

    Collins, Richard

    2010-01-01

    Full text: First there was the Beer Battery, which aimed to generate electricity from brewery wastewater using a microbial fuel cell (MFC). Trials at Foster's Yatala brewery in Queensland in 2007 ran into challenges around the cost of electricity and duration of treatment, but they also revealed a new possibility. Komeel Rabaey, a University of Queensland specialist in microbial dynamics with a particular passion for bioelectrochemical systems, recognised the potential to extract sodium hydroxide - caustic soda - out of wastewater in a form suitable for reuse. In 2008 he converted such a system into a lab-scale caustic recovery plant, then upsized it to a one litre test reactor, which is again running at the Yatala brewery. The concept flips wastewater treatment on its head, seeing the discharge as a resource to be harvested rather than a cost and a contaminant load to be managed. “We typically aim to make a concentration of about four per cent caustic. That is what is easily achievable with the system and you will also note a lot of industries use caustic at four per cent,” said Dr Rabaey. “So you can use the wastewater from the plant to drive caustic production, with the extra advantage of removing enormous amounts of sodium.” Sodium hydroxide is a ubiquitous industrial compound used in pH regulation, as a cleaning agent in clean-in-place systems and variously in pulp and paper, textiles and food processing. Dr Rabaey wants to close the loop on caustic. Industries along the Murray-Darling basin, for example, truck in a lot of it from outside the area and then discharge it with their wastewater into the salt-sensitive river system. “If you use a bioelectrochemical system to recover the sodium hydroxide, you are not even importing the sodium into the area but recycling the sodium the whole time on-site,” he told WME. Get the technology right and he reckons a three-year payback on investment is readily achievable. A microbial fuel cell oxidises organics

  3. [Ozone concentration distribution of urban].

    Science.gov (United States)

    Yin, Yong-quan; Li, Chang-mei; Ma, Gui-xia; Cui, Zhao-jie

    2004-11-01

    The increase of ozone concentration in urban is one of the most important research topics on environmental science. With the increase of nitrogen oxides and hydrogen-carbon compounds which are exhausted from cars, the ozone concentration in urban is obviously increased on sunlight, and threat of photochemistry smog will be possible. Therefore, it is very important to monitor and study the ozone concentration distribution in urban. The frequency-distribution, diurnal variation and monthly variation of ozone concentration were studied on the campus of Shandong University during six months monitoring. The influence of solar radiation and weather conditions on ozone concentration were discussed. The frequency of ozone concentration less than 200 microg/m3 is 96.88%. The ozone concentration has an obvious diurnal variation. The ozone concentration in the afternoon is higher than in the morning and in the evening. The maximum appears in June, when it is the strong solar radiation and high air-temperature. The weather conditions also influence the ozone concentration. The ozone concentration in clear day is higher than in rainy and cloudy day.

  4. Low concentrator PV optics optimization

    Science.gov (United States)

    Sharp, Leonard; Chang, Ben

    2008-08-01

    Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

  5. Optical assessment of nonimaging concentrators.

    Science.gov (United States)

    Timinger, A; Kribus, A; Ries, H; Smith, T; Walther, M

    2000-11-01

    An optical measurement method for nonimaging radiation concentrators is proposed. A Lambertian light source is placed in the exit aperture of the concentrator. Looking into the concentrator's entrance aperture from a remote position, one can photograph the transmission patterns. The patterns show the transmission of radiation through the concentrator with the full resolution of the four-dimensional phase space of geometric optics. By matching ray-tracing simulations to the measurement, one can achieve detailed and accurate information about the geometry of the concentrator. This is a remote, noncontact measurement and can be performed in situ for installed concentrators. Additional information regarding small-scale reflector waviness and surface reflectivity can also be obtained from the same measurement with additional analysis.

  6. Maximum Permissible Concentrations and Negligible Concentrations for pesticides

    NARCIS (Netherlands)

    Crommentuijn T; Kalf DF; Polder MD; Posthumus R; Plassche EJ van de; CSR

    1997-01-01

    Maximum Permissible Concentrations (MPCs) and Negligible Concentrations (NCs) derived for a series of pesticides are presented in this report. These MPCs and NCs are used by the Ministry of Housing, Spatial Planning and the Environment (VROM) to set Environmental Quality Objectives. For some of the

  7. Ideal 3D asymmetric concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Botella, Angel [Departamento Fisica Aplicada a los Recursos Naturales, Universidad Politecnica de Madrid, E.T.S.I. de Montes, Ciudad Universitaria s/n, 28040 Madrid (Spain); Fernandez-Balbuena, Antonio Alvarez; Vazquez, Daniel; Bernabeu, Eusebio [Departamento de Optica, Universidad Complutense de Madrid, Fac. CC. Fisicas, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2009-01-15

    Nonimaging optics is a field devoted to the design of optical components for applications such as solar concentration or illumination. In this field, many different techniques have been used for producing reflective and refractive optical devices, including reverse engineering techniques. In this paper we apply photometric field theory and elliptic ray bundles method to study 3D asymmetric - without rotational or translational symmetry - concentrators, which can be useful components for nontracking solar applications. We study the one-sheet hyperbolic concentrator and we demonstrate its behaviour as ideal 3D asymmetric concentrator. (author)

  8. Antibiotic concentrations in intestinal mucosa.

    Science.gov (United States)

    Malmborg, A S

    1985-01-01

    The concentrations in the intestinal mucosa after the initial dose of cefoxitin, piperacillin and clindamycin have been studied. The antibiotics were given at the induction of anesthesia as prophylaxis to patients undergoing elective colorectal surgery. The concentrations of the antibiotics in serum and intestinal mucosa taken during the operation were determined by the microbiological agar diffusion method. Therapeutic concentrations in intestinal mucosa were maintained during the major part of the operation period. The mean mucosa/serum concentration ratios were for cefoxitin 0.4, for piperacillin 0.5 and for clindamycin 1.2.

  9. School concentration and school travel

    NARCIS (Netherlands)

    De Boer, E.

    2010-01-01

    The purpose of the research as described in this Doctor’s thesis is twofold. Firstly it is to define in how far Dutch facilities for primary and secondary education were subjected to spatial concentration during recent decades. Secondly it is intended to assess what this concentration implied for

  10. Optimal concentrations in transport systems

    Science.gov (United States)

    Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

    2013-01-01

    Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

  11. Micro-evaporation electrolyte concentrator

    NARCIS (Netherlands)

    Timmer, B.H.; van Delft, K.M.; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

    2003-01-01

    The sensitivity of miniaturized chemical analysis systems depends most of the time on the obtainable detection limit. Concentrating the analyte prior to the detection system can enhance the detection limit. In this writing an analyte concentrator is presented that makes use of evaporation to

  12. Radon concentration in The Netherlands

    International Nuclear Information System (INIS)

    Meijer, R.J. de; Put, L.W.; Veldhuizen, A.

    1986-02-01

    In 1000 dwellings, which can be assumed to be an reasonable representation of the average Dutch dwellings, time averaged radon concentrations, radon daughter concentrations and gamma-exposure tempi are determined during a year with passive dosemeters. They are also determined outdoor at circa 200 measure points. (Auth.)

  13. Ion climate and radon concentration

    International Nuclear Information System (INIS)

    Busbarna, L.

    1981-01-01

    Characteristic values of radon concentration in natural ion climate and in open air were compared and the effect of artificially produced negative ion excess on the radon concentration of air was studied. The results show that the radon concentration measurable at the rise of negative ion excess is smaller than that in the case of natural equilibrium. This effect can be utilized lowering the background of the scintillation chambers, thus increasing their sensitivity. The negative ions of the artificial ion climate lower radon concentration in closed space. The question arises whether only the ion climate is responsible for the effects on the organism and on the nervous system or the radon concentration of the air also contributes to them. (author)

  14. Ownership concentration and bank profitability

    Directory of Open Access Journals (Sweden)

    Peterson Kitakogelu Ozili

    2017-12-01

    Full Text Available We investigate whether ownership concentration influences bank profitability in a developing country context. We focus on bank ownership concentration measured as the amount of direct equity held by a majority shareholder categorised into: high ownership concentration, moderate ownership concentration and disperse ownership. We find that banks with high ownership concentration have higher return on assets, higher net interest margin and higher recurring earning power while banks with dispersed ownership have lower return on assets but have higher return on equity. Also, higher cost efficiency improves the return on assets of widely-held banks and the return on equity of banks with moderate ownership. The findings have implications. JEL: Code: G3, G34, G31, Keywords: Corporate governance, Ownership structure, Agency theory, Profitability, Firm performance, Banks, Return on asset, Return on equity

  15. Ideal flux field dielectric concentrators.

    Science.gov (United States)

    García-Botella, Angel

    2011-10-01

    The concept of the vector flux field was first introduced as a photometrical theory and later developed in the field of nonimaging optics; it has provided new perspectives in the design of concentrators, overcoming standard ray tracing techniques. The flux field method has shown that reflective concentrators with the geometry of the field lines achieve the theoretical limit of concentration. In this paper we study the role of surfaces orthogonal to the field vector J. For rotationally symmetric systems J is orthogonal to its curl, and then a family of surfaces orthogonal to the lines of J exists, which can be called the family of surfaces of constant pseudopotential. Using the concept of the flux tube, it is possible to demonstrate that refractive concentrators with the shape of these pseudopotential surfaces achieve the theoretical limit of concentration.

  16. Tank waste concentration mechanism study

    International Nuclear Information System (INIS)

    Pan, L.C.; Johnson, L.J.

    1994-09-01

    This study determines whether the existing 242-A Evaporator should continue to be used to concentrate the Hanford Site radioactive liquid tank wastes or be replaced by an alternative waste concentration process. Using the same philosophy, the study also determines what the waste concentration mechanism should be for the future TWRS program. Excess water from liquid DST waste should be removed to reduce the volume of waste feed for pretreatment, immobilization, and to free up storage capacity in existing tanks to support interim stabilization of SSTS, terminal cleanout of excess facilities, and other site remediation activities

  17. Fibrinogen concentrate in bleeding patients

    DEFF Research Database (Denmark)

    Wikkelsø, Anne; Lunde, Jens; Johansen, Mathias

    2013-01-01

    Hypofibrinogenaemia is associated with increased morbidity and mortality, but the optimal treatment level, the use of preemptive treatment and the preferred source of fibrinogen remain disputed. Fibrinogen concentrate is increasingly used and recommended for bleeding with acquired haemostatic...

  18. Thermodynamic efficiency of solar concentrators.

    Science.gov (United States)

    Shatz, Narkis; Bortz, John; Winston, Roland

    2010-04-26

    The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency.

  19. Ultra Low Concentration Adsorption Equilibria

    National Research Council Canada - National Science Library

    Mahle, John J; Buettner, Leonard C; LeVan, M. D; Schindler, Bryan J

    2006-01-01

    .... Specifically this work focuses on novel experimental and modeling methods to characterize and predict at ultra-low chemical vapor concentrations the protection afforded by adsorption-based vapor filtration systems...

  20. Adiabatic theorem and spectral concentration

    International Nuclear Information System (INIS)

    Nenciu, G.

    1981-01-01

    The spectral concentration of arbitrary order, for the Stark effect is proved to exist for a large class of Hamiltonians appearing in nonrelativistic and relativistic quantum mechanics. The results are consequences of an abstract theorem about the spectral concentration for self-ad oint operators. A general form of the adiabatic theorem of quantum mechanics, generalizing an earlier result of the author as well as some results of Lenard, is also proved [ru

  1. Thermodynamic efficiency of nonimaging concentrators

    Science.gov (United States)

    Shatz, Narkis; Bortz, John; Winston, Roland

    2009-08-01

    The purpose of a nonimaging concentrator is to transfer maximal flux from the phase space of a source to that of a target. A concentrator's performance can be expressed relative to a thermodynamic reference. We discuss consequences of Fermat's principle of geometrical optics. We review étendue dilution and optical loss mechanisms associated with nonimaging concentrators, especially for the photovoltaic (PV) role. We introduce the concept of optical thermodynamic efficiency which is a performance metric combining the first and second laws of thermodynamics. The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. Examples are provided to illustrate the use of this new metric. In particular we discuss concentrating PV systems for solar power applications.

  2. F19 relaxation in non-magnetic hexafluorides

    International Nuclear Information System (INIS)

    Rigny, P.

    1969-01-01

    The interesting properties of the fluorine magnetic resonance in the hexafluorides of molybdenum, tungsten and uranium, are very much due to large anisotropies of the chemical shift tensors. In the solid phases these anisotropies, the values of which are deduced from line shape studies, allow one to show that the molecules undergo hindered rotations about the metal atom. The temperature and frequency dependence of the fluorine longitudinal relaxation times shows that the relaxation is due to the molecular motion. The dynamical parameters of this motion are then deduced from the complete study of the fluorine relaxation in the rotating frame. In the liquid phases, the existence of anisotropies allows an estimation of the different contributions to the relaxation. In particular, the frequency and temperature dependence of the relaxation shows it to be dominated by the spin-rotation interaction. We have shown that the strength of this interaction can be deduced from the chemical shifts, and the angle through which the molecule rotates quasi-freely can be determined. In the hexafluorides, this angle is roughly one radian at 70 C, and with the help of this value, the friction coefficients which describe the intermolecular interactions are discussed. (author) [fr

  3. Structural and electronic properties of non-magnetic intermetallic ...

    Indian Academy of Sciences (India)

    LAPW) method based on the density functional theory (DFT), within the generalized gradient approximation. (GGA). ... A class of compounds that has attracted a great attention in recent years is RETX, .... states (DOS) was determined by the tetrahedral integration ... The features of the occupied densities of states for both ...

  4. Modeling of rotational induction heating of nonmagnetic cylindrical billets

    Czech Academy of Sciences Publication Activity Database

    Karban, P.; Mach, F.; Doležel, Ivo

    2013-01-01

    Roč. 219, č. 13 (2013), s. 7170-7180 ISSN 0096-3003 Grant - others:GA ČR(CZ) GAP102/10/0216 Program:GA Institutional support: RVO:61388998 Keywords : induction heating * magnetic field * temperature field Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.600, year: 2013 http://www.journals.elsevier.com/applied-mathematics- and -computation/

  5. Nonmagnetic ground state of PuO.sub.2./sub

    Czech Academy of Sciences Publication Activity Database

    Shick, Alexander; Kolorenč, Jindřich; Havela, L.; Gouder, T.; Caciuffo, R.

    2014-01-01

    Roč. 89, č. 4 (2014), "041109-1"-"041109-4" ISSN 1098-0121 R&D Projects: GA ČR(CZ) GAP204/10/0330 Institutional support: RVO:68378271 Keywords : actinides * strongly correlated electrons * LDA+DMFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014 http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.041109

  6. Crystal field of Dy in non-magnetic metals

    NARCIS (Netherlands)

    Kikkert, Pieter Jan Willem

    1980-01-01

    Many investigations carried out during the last 15 years have demonstrated that the crystalline electric field (CEF) has a great influence on the low temperature magnetic behaviour of rare earth ions in metallic systems (see e.g. /1/) . It is therefore important to understand the origin of the CEF

  7. Integral Model of Eddy Currents in Nonmagnetic Structures

    Czech Academy of Sciences Publication Activity Database

    Doležel, Ivo; Karban, P.

    2004-01-01

    Roč. 4, č. 3 (2004), s. 5-12 ISSN 1335-8243 R&D Projects: GA ČR GA102/03/0047 Keywords : magnetic field * eddy currents * integral equations Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  8. Circular polarization in a non-magnetic resonant tunneling device

    Directory of Open Access Journals (Sweden)

    Airey Robert

    2011-01-01

    Full Text Available Abstract We have investigated the polarization-resolved photoluminescence (PL in an asymmetric n-type GaAs/AlAs/GaAlAs resonant tunneling diode under magnetic field parallel to the tunnel current. The quantum well (QW PL presents strong circular polarization (values up to -70% at 19 T. The optical emission from GaAs contact layers shows evidence of highly spin-polarized two-dimensional electron and hole gases which affects the spin polarization of carriers in the QW. However, the circular polarization degree in the QW also depends on various other parameters, including the g-factors of the different layers, the density of carriers along the structure, and the Zeeman and Rashba effects.

  9. Concentrating Solar Power Projects - Planta Solar 20 | Concentrating Solar

    Science.gov (United States)

    Power | NREL 20 This page provides information on Planta Solar 20, a concentrating solar power Solar's Planta Solar 20 (PS20) is a 20-megawatt power tower plant being constructed next to the PS10 tower and increasing incident solar radiation capture will increase net electrical power output by 10

  10. Concentrating Solar Power Projects - Nevada Solar One | Concentrating Solar

    Science.gov (United States)

    Power | NREL Nevada Solar One This page provides information on Nevada Solar One, a concentrating solar power (CSP) project, with data organized by background, participants, and power plant configuration. Acciona Energy's Nevada Solar One is the third largest CSP plant in the world and the first plant

  11. Concentrating Solar Power Projects - Khi Solar One | Concentrating Solar

    Science.gov (United States)

    Power | NREL Khi Solar One This page provides information on Khi Solar One, a concentrating solar power (CSP) project, with data organized by background, parcipants and power plant configuration . Status Date: February 8, 2016 Project Overview Project Name: Khi Solar One Country: South Africa Location

  12. concentrate ratio and rumen ammonia concentration on in situ

    African Journals Online (AJOL)

    The aim of this experiment was to distinguish between the effects of dietary roughage: concentrate ratio and rumen ammonia ... several factors which include the potential rate and extent of degradation of the test feedstuff and the prevailing rate of ... diet effects have be,en designed to examine either the influence of dietary ...

  13. Concentric retinitis pigmentosa: clinicopathologic correlations.

    Science.gov (United States)

    Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G

    2001-10-01

    Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective

  14. Concentrator-solar-cell development

    Science.gov (United States)

    Grenon, L.

    1982-07-01

    A program is described which is a continuation of earlier programs for the development of high-efficiency, low-cost, silicon concentrator solar cells. The base-line process steps and process sequences identified in these earlier contracts were evaluated and specific processes reviewed. In particular, emphasis on the use of Czochralski-grown silicon wafers rather than float-zone wafers were examined. Additionally, a study of the trade-offs between textured and nontextured cells was initiated, and the limits within which the low-cost plated nickel copper metallization can be used in concentrator solar cell applications was identified.

  15. Improved ATIR concentrator photovoltaic module

    Science.gov (United States)

    Adriani, Paul M.; Mao, Erwang

    2013-09-01

    Novel aggregated total internal reflection (ATIR) concentrator photovoltaic module design comprises 2-D shaped primary and secondary optics that effectively combine optical efficiency, low profile, convenient range of acceptance angles, reliability, and manufacturability. This novel optical design builds upon previous investigations by improving the shapes of primary and secondary optics to enable improved long-term reliability and manufacturability. This low profile, low concentration (5x to 10x) design fits well with one-axis trackers that are often used for flat plate crystalline silicon photovoltaic modules in large scale ground mount installations. Standard mounting points, materials, and procedures apply without changes from flat plate modules.

  16. Indoor radon concentration in Poland

    International Nuclear Information System (INIS)

    Mamont-Ciesla, K.; Jagielak, J.; Rosinski, S.W.; Sosinka, A.; Bysiek, M.; Henschke, J.

    1996-01-01

    Preliminary survey of Rn concentration indoors by means of track detectors and y-ray dose rate with the use of TLD in almost 500 homes in selected areas of Poland was performed in the late 1980s. It was concluded that radon contributes 1.16 mSv i.e. about 46 per cent of the total natural environment ionizing radiation dose to the Polish population. Comparison of the average radon concentrations in 4 seasons of a year and in 3 groups of buildings: masonry, concrete and wood, revealed that the ground beneath the building structure is likely the dominant source of radon indoors. Since the National Atomic Energy Agency in its regulations of 1988-03-31 set up the permissible limit of the equilibrium equivalent concentration of radon in new buildings (equal 100 Bq/m3), the nation-scale survey project for radon in buildings has been undertaken. These regulations were supposed to take effect in 1995-01-01. The project has 3 objectives: to estimate the radiation exposure due to radon daughters received by Polish population to identify radon-prone areas in Poland to investigate dependence of the indoor radon concentrations on such parameters as: type of construction material, presence (or absence) of cellar under the building, number of floor

  17. Uranium concentrations in human bone

    International Nuclear Information System (INIS)

    Schlenker, R.A.; Oltman, B.G.

    1981-01-01

    The uranium concentration in bone from an individual injected with 239 Pu has been determined, using the fission-track method. The data are consistent with those reported about 10 years ago by Welford and Baird for New York City area residents and by Hamilton in England. They are at variance with the more recent data of Welford et al

  18. Error exponents for entanglement concentration

    International Nuclear Information System (INIS)

    Hayashi, Masahito; Koashi, Masato; Matsumoto, Keiji; Morikoshi, Fumiaki; Winter, Andreas

    2003-01-01

    Consider entanglement concentration schemes that convert n identical copies of a pure state into a maximally entangled state of a desired size with success probability being close to one in the asymptotic limit. We give the distillable entanglement, the number of Bell pairs distilled per copy, as a function of an error exponent, which represents the rate of decrease in failure probability as n tends to infinity. The formula fills the gap between the least upper bound of distillable entanglement in probabilistic concentration, which is the well-known entropy of entanglement, and the maximum attained in deterministic concentration. The method of types in information theory enables the detailed analysis of the distillable entanglement in terms of the error rate. In addition to the probabilistic argument, we consider another type of entanglement concentration scheme, where the initial state is deterministically transformed into a (possibly mixed) final state whose fidelity to a maximally entangled state of a desired size converges to one in the asymptotic limit. We show that the same formula as in the probabilistic argument is valid for the argument on fidelity by replacing the success probability with the fidelity. Furthermore, we also discuss entanglement yield when optimal success probability or optimal fidelity converges to zero in the asymptotic limit (strong converse), and give the explicit formulae for those cases

  19. Particle interactions in concentrated suspensions

    International Nuclear Information System (INIS)

    Mondy, L.A.; Graham, A.L.; Abbott, J.R.; Brenner, H.

    1993-01-01

    An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. The authors describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. The authors suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. They also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, they briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions

  20. Freeform optics for photovoltaic concentration

    OpenAIRE

    Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos

    2012-01-01

    Freeform surfaces are the key of the state-of-the-art nonimaging optics to solve the challenges in concentration photovoltaics. Different families (FK, XR, FRXI) will be presented, based on the SMS 3D design method and Köhler homogenization.

  1. Cesium Concentration in MCU Solvent

    International Nuclear Information System (INIS)

    Walker, D

    2006-01-01

    During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

  2. Concentrations: Recent Developments in Italy

    Directory of Open Access Journals (Sweden)

    Claudio Tesauro

    2015-10-01

    Full Text Available Recent Italian developments in antitrust concentrations was the topic I was assigned to address at the conference held on 23 April to celebrate the first anniversary of the Italian Antitrust Review. What is immediately clear is that far fewer concentrations have been notified over the last few years. This is probably due to the economic crisis, which caused a reduction in corporate transactions; but also the changes to the turnover thresholds for notification seem to have had a significant impact. Consequently, an interesting debate is underway regarding the need for further changes the threshold system. Moreover, the drastic market developments and the subsequent increased number of decisions to revise remedies should also be further examined. These two issues are the subject of this paper.

  3. Cylindrical acoustic levitator/concentrator

    Science.gov (United States)

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  4. BASIC FACTORS OF MARKET CONCENTRATION

    OpenAIRE

    V. Fyliuk

    2013-01-01

    The paper systemizes factors which reinforce trends towards market concentration in all economic systems. These factors include factors related to the general changes in economic environment such as globalization of the world economy, state structural and taxation policies, cycle of economic development and changes in consumer demand. They also include factors related to competition (intensification of competition, companies’ desire to monopolize market and present market structure) and scien...

  5. Experience in handling concentrated tritium

    International Nuclear Information System (INIS)

    Holtslander, W.J.

    1985-12-01

    The notes describe the experience in handling concentrated tritium in the hydrogen form accumulated in the Chalk River Nuclear Laboratories Tritium Laboratory. The techniques of box operation, pumping systems, hydriding and dehydriding operations, and analysis of tritium are discussed. Information on the Chalk River Tritium Extraction Plant is included as a collection of reprints of papers presented at the Dayton Meeting on Tritium Technology, 1985 April 30 - May 2

  6. Arsenic concentrations in Chinese coals

    International Nuclear Information System (INIS)

    Wang Mingshi; Zheng Baoshan; Wang Binbin; Li Shehong; Wu Daishe; Hu Jun

    2006-01-01

    The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the concentration of Arsenic is 6.4 ± 0.5 mg/kg and the geometric mean is 4.0 ± 8.5 mg/kg. The level of arsenic in China is higher in northeastern and southern provinces, but lower in northwestern provinces. The relationship between arsenic content and coal-forming period, coal rank is studied. It was observed that the arsenic contents decreases with coal rank in the order: Tertiary > Early Jurassic > Late Triassic > Late Jurassic > Middle Jurassic > Late Permian > Early Carboniferous > Middle Carboniferous > Late Carboniferous > Early Permian; It was also noted that the arsenic contents decrease in the order: Subbituminous > Anthracite > Bituminous. However, compared with the geological characteristics of coal forming region, coal rank and coal-forming period have little effect on the concentration of arsenic in Chinese coal. The average arsenic concentration of Chinese coal is lower than that of the whole world. The health problems in China derived from in coal (arsenism) are due largely to poor local life-style practices in cooking and home heating with coal rather than to high arsenic contents in the coal

  7. REM-containing silicate concentrates

    International Nuclear Information System (INIS)

    Pavlov, V F; Shabanova, O V; Pavlov, I V; Pavlov, M V; Shabanov, A V

    2016-01-01

    A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM. (paper)

  8. REM-containing silicate concentrates

    Science.gov (United States)

    Pavlov, V. F.; Shabanova, O. V.; Pavlov, I. V.; Pavlov, M. V.; Shabanov, A. V.

    2016-01-01

    A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

  9. Pressure leaching of chalcopyrite concentrate

    Science.gov (United States)

    Aleksei, Kritskii; Kirill, Karimov; Stanislav, Naboichenko

    2018-05-01

    The results of chalcopyrite concentrate processing using low-temperature and high-temperature sulfuric acid pressure leaching are presented. A material of the following composition was used, 21.5 Cu, 0.1 Zn, 0.05 Pb, 0.04 Ni, 26.59 S, 24.52 Fe, 16.28 SiO2 (in wt.%). The influence of technological parameters on the degree of copper and iron extraction into the leach solution was studied in the wide range of values. The following conditions were suggested as the optimal for the high-temperature pressure leaching: t = 190 °C, PO2 = 0.5 MPa, CH2SO4 = 15 g/L, L:S = 6:1. At the mentioned parameters, it is possible to extract at least 98% Cu from concentrate into the leaching solution during 100 minutes. The following conditions were suggested as optimal for the low-temperature pressure leaching: t = 105 °C, PO2 = 1.3-1.5 MPa, CH2SO4 = 90 g/L, L:S = 10:1. At the mentioned parameters, it is possible to extract up to 83% Cu from the concentrate into the leach solution during 300-360 minutes.

  10. Photovoltaic concentrator module improvements study

    Energy Technology Data Exchange (ETDEWEB)

    Levy, S.L.; Kerschen, K.A. (Black and Veatch, Kansas City, MO (United States)); Hutchison, G. (Solar Kinetics, Inc., Dallas, TX (United States)); Nowlan, M.J. (Spire Corp., Bedford, MA (United States))

    1991-08-01

    This report presents results of a project to design and fabricate an improved photovoltaic concentrator module. Using previous work as a baseline, this study conducted analyses and testing to select major module components and design features. The lens parquet and concentrator solar cell were selected from the highest performing, available components. A single 185X point-focus module was fabricated by the project team and tested at Sandia. Major module characteristics include a 6 by 4 compression-molded acrylic lens parquet (0.737 m{sup 2} area), twenty-four 0.2 ohms-cm, FZ, p-Si solar cells (1.56 cm{sup 2} area) soldered to ceramic substrates and copper heat spreaders, and an aluminized steel housing with corrugated bottom. This project marked the first attempt to use prismatic covers on solar cells in a high-concentration, point-focus application. Cells with 15 percent metallization were obtained, but problems with the fabrication and placement of prismatic covers on these cells lead to the decision not to use covers in the prototype module. Cell assembly fabrication, module fabrication, and module optical design activities are presented here. Test results are also presented for bare cells, cell assemblies, and module. At operating conditions of 981 watts/m{sup 2} DNI and an estimated cell temperature of 65{degrees}C, the module demonstrated an efficiency of 13.9 percent prior to stressed environmental exposure. 12 refs., 56 figs., 7 tabs.

  11. Study on mineral processing technology for abrasive minerals

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seong Woong; Yang, Jung Il; Hwang, Seon Kook; Choi, Yeon Ho; Cho, Ken Joon; Shin, Hee Young [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    Buyeo Materials in Buyeogun, Choongnam province is a company producing feldspar concentrate, but does not yet utilize the garnet as abrasive material and other useful heavy minerals wasted out from the process of feldspar ore. The purpose of this study is to develop technology and process for the recovery of garnet concentrate. As results, the garnet is defined as ferro manganese garnet. The optimum process for recovery of garnet concentrate is to primarily concentrate heavy minerals from tailings of feldspar processing. And secondly the heavy minerals concentrated is dried and separated garnet concentrate from other heavy minerals. At this time, the garnet concentrate is yield by 0.176%wt from 0.31%wt of heavy minerals in head ore. The garnet concentrate contains 33.35% SiO{sub 2}, 12.20% Al{sub 2}O{sub 3}, 28.47% Fe{sub 2}O{sub 3}, 11.96% MnO. As for utilization of abrasive materials, a fundamental data was established on technology of grinding and classification. (author). 13 refs., 47 figs., 24 tabs.

  12. Construction of a forensic soil database of the Hokkaido region in Japan by synchrotron radiation X-ray analysis

    International Nuclear Information System (INIS)

    Shirota, Yusuke; Hirao, Masataka; Abe, Yoshinari; Nakai, Izumi; Osaka, Keiichi; Itou, Masayoshi

    2017-01-01

    The purpose of the present study is to construct a nation-wide forensic soil database, which allows for the identification of soil evidence based on heavy element and heavy mineral signatures determined by two synchrotron radiation (SR) X-ray techniques, i.e., a high-energy synchrotron radiation X-ray fluorescence analysis and a synchrotron-radiation X-ray powder diffraction analysis, respectively. The heavy element and heavy mineral compositions of the stream sediments collected at 3024 points located all over Japan were measured by the two SR X-ray techniques. The present paper focuses on a regional characterization of the sediments collected from the Hokkaido areas. The concentrations of heavy elements and heavy minerals in the Hokkaido areas were visualized as maps that enable us to compare the heavy element and heavy mineral compositions with the geological context of the samples. Based on a hierarchical cluster analysis using the semi-quantitative compositions of the heavy minerals, we could successfully classify the sediments into six groups corresponding to their background geologies. A Bonferroni multiple comparison demonstrated that these six groups also have significant differences in the heavy element composition. From these examinations, we could demonstrate that detailed regional identification of unknown samples is possible by analyzing both heavy element and heavy mineral compositions of each sample. (author)

  13. Plasma leptin concentration in donkeys.

    Science.gov (United States)

    Díez, E; López, I; Pérez, C; Pineda, C; Aguilera-Tejero, E

    2012-01-01

    Donkeys appear to be more predisposed than large breed horses to suffer from hyperlipemia. The reason for that predisposition is unknown but anorexia is a consistent feature of the disease. Leptin, a protein synthesized in fat tissue, is one of the major inhibitors of appetite in mammals. We hypothesized that donkeys could have elevated plasma leptin concentrations compared to horses. Blood samples were obtained from 50 donkeys for measurement of leptin, triglycerides (TGs), glucose, and insulin. Glucose/insulin ratio, modified insulin to glucose ratio, and reciprocal of the square root of insulin were calculated. Based on their body condition score (BCS), donkeys were classified as lean (n = 18), normal (n = 16), or overweight (n = 16). The results were compared with reference values from our laboratory and with a group of horses (n = 25) used as an internal control. Values of both leptin and TGs in donkeys were above the horse reference range and also significantly higher than those of the control horses: leptin (11.2 ± 1.7 versus 5.8 ± 0.5 µg/L, p donkeys had leptin (19.3 ± 2.9 µg/L) and TG (1.3 ± 0.2 mmol/L) concentrations that were significantly (p donkeys. A significant positive correlation (p Donkeys have higher plasma leptin concentrations than horses and leptin is correlated with BCS.

  14. Factors influencing erythrocyte choline concentrations.

    Science.gov (United States)

    Miller, B L; Jenden, D J; Tang, C; Read, S

    1989-01-01

    Choline concentrations in human erythrocytes increase after freezing and thawing, during incubation in Krebs-phosphate for 30 min or on storage at 0 degrees C for 3-24 hr. The increase is prevented by protein precipitation by 10% perchloric acid, 10% zinc hydroxide, 10% sodium tungstate or boiling in water. It is not prevented by EDTA (10 mM) and is increased by oleate (5 mM). We suggest that the increase is due to the action of phospholipase D on erythrocyte phospholipids.

  15. Concentrated photovoltaics, a case study

    Directory of Open Access Journals (Sweden)

    Antonini Piergiorgio

    2014-01-01

    Full Text Available Concentrated Photovoltaics (CPV, once a niche technology, has now reached the maturity and reliability for large scale power generation. Especially in regions where temperatures are very high, the use of high efficiency triple junction solar cells with concentrating optics allows stable energy yield. Thus CPV can be seen as complementary and not in concurrence with silicon photovoltaics. The state of the art, the advantages and limitations of this technology will be shown. Among the main advantages of CPV is the possibility of a much higher energy supply, when compared to silicon photovoltaics, both comparing CPV and silicon with same area or the same installed power. The use of recycled and recyclable materials allows a more environmentally friendly production. The possibility to couple CPV with desalination facilities, energy storage will be analysed. As an example a case study of a CPV installation in Northern Italy is discussed. Here the use of mature technologies, derived from automotive and lighting sectors resulted in a simple and efficient module.

  16. Technology Roadmaps: Concentrating Solar Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The emerging technology known as concentrating solar power, or CSP, holds much promise for countries with plenty of sunshine and clear skies. Its electrical output matches well the shifting daily demand for electricity in places where airconditioning systems are spreading. When backed up by thermal storage facilities and combustible fuel, it offers utilities electricity that can be dispatched when required, enabling it to be used for base, shoulder and peak loads. Within about one to two decades, it will be able to compete with coal plants that emit high levels of CO2. The sunniest regions, such as North Africa, may be able to export surplus solar electricity to neighbouring regions, such as Europe, where demand for electricity from renewable sources is strong. In the medium-to-longer term, concentrating solar facilities can also produce hydrogen, which can be blended with natural gas, and provide low-carbon liquid fuels for transport and other end-use sectors. For CSP to claim its share of the coming energy revolution, concerted action is required over the next ten years by scientists, industry, governments, financing institutions and the public. This roadmap is intended to help drive these indispensable developments.

  17. Concentration - dose - risk computer code

    International Nuclear Information System (INIS)

    Frujinoiu, C.; Preda, M.

    1997-01-01

    Generally, the society is less willing in promoting remedial actions in case of low level chronic exposure situations. Radon in dwellings and workplaces is a case connected to chronic exposure. Apart from radon, the solely source on which the international community agreed for setting action levels, there are other numerous sources technically modified by man that can generate chronic exposure. Even if the nuclear installations are the most relevant, we are surrounded by 'man-made radioactivity' such as: mining industry, coal-fired power plants and fertilizer industry. The operating of an installation even within 'normal limits' could generate chronic exposure due to accumulation of the pollutants after a definite time. This asymptotic proclivity to a constant level define a steady-state concentration that represents a characteristic of the source's presence in the environment. The paper presents a methodology and a code package that derives sequentially the steady-state concentration, doses, detriments, as well as the costs of the effects of installation operation in a given environment. (authors)

  18. Freeze concentration of lime juice

    Directory of Open Access Journals (Sweden)

    Ampawan Tansakul

    2008-11-01

    Full Text Available The main objective of this research was to study the effects of processing conditions, i.e. cooling medium temperature (-6, -12 and -18C and scraper blade rotational speed (50, 100 and 150 rpm on the freeze concentration of lime juice. The initial soluble solid content of lime juice was 7.6 Brix. Results showed that soluble solid content of lime juice increased as cooling medium temperature decreased while scraper blade rotational speed increased. It was also found that the processing condition with -18˚C cooling medium temperature and 150 rpm rotational speed of the scraper blade was the best among all studied conditions, although the loss of the soluble solids with ice crystals during ice separation was relatively high at 35%.

  19. The concentration of retail in Poland

    Directory of Open Access Journals (Sweden)

    Michał Gazdecki

    2010-01-01

    Full Text Available The article discusses the processes of concentration taking place in retail in Poland. In spite of strong concentration processes, which took place after 2000, Poland still remains a country of dispersed retail structure. In the nearest years we can expect capital concentration (mainly takeovers in modern trade and contract concentration (for example, merchants’ societies in traditional trade.

  20. Concentrating Solar Power. Technology Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Concentrating solar power can contribute significantly to the world's energy supply. As shown in this roadmap, this decade is a critical window of opportunity during which CSP could become a competitive source of electrical power to meet peak and intermediate loads in the sunniest parts of the world. This roadmap identifies technology, economy and policy goals and milestones needed to support the development and deployment of CSP, as well as ongoing advanced research in CSF. It also sets out the need for governments to implement strong, balanced policies that favour rapid technological progress, cost reductions and expanded industrial manufacturing of CSP equipment to enable mass deployment. Importantly, this roadmap also establishes a foundation for greater international collaboration. The overall aim of this roadmap is to identify actions required - on the part of all stakeholders - to accelerate CSP deployment globally. Many countries, particularly in emerging regions, are only just beginning to develop CSP. Accordingly, milestone dates should be considered as indicative of urgency, rather than as absolutes. This roadmap is a work in progress. As global CSP efforts advance and an increasing number of CSP applications are developed, new data will provide the basis for updated analysis. The IEA will continue to track the evolution of CSP technology and its impacts on markets, the power sector and regulatory environments, and will update its analysis and set additional tasks and milestones as new learning comes to light.

  1. Urinary concentrating processes in vertebrates.

    Science.gov (United States)

    Schmidt-Nielsen, B.

    1979-01-01

    Avian and mammalian kidneys can produce a urine hyperosmotic to the blood by means of a renal countercurrent system. Birds are uricotelic; mammals are ureotelic. It is proposed that the inner medulla present in mammalian, but not in avian kidneys serves specifically to accumulate urea in the inner and outer medulla. Among mammalian kidneys the degree to which urea accumulates in the inner medulla is inversely related to the complexity of the vascular bundles (in the outer medulla) and the cortical urea recycling index. A model is proposed for urea recycling via the vascular bundles. The renal pelvis varies in size among mammals. Its relative size is unrelated to the type of vascular bundles, cortical recycling index; or urea accumulation in the inner medulla. Since urine refluxes into the renal pelvis during rising urine flow only, the function of the pelvis could be that of bringing the more dilute urine into contact with the outer medulla and underlying capillaries, thereby aiding in reducing the urea concentration in outer and inner medulla during rising urine flow. The size of the renal pelvis may be related to the volume of the inner medulla. Other factors may also be involved. Images FIG. 1 FIG. 3 FIG. 5 FIG. 6 FIG. 9 FIG. 10 FIG. 11 FIG. 12 FIG. 13 PMID:538955

  2. Transparent heavy minerals in the coastal sediments of south Maharashtra and their significance in delineating source and environment of transportation and deposition

    Digital Repository Service at National Institute of Oceanography (India)

    Mislankar, P.G.; Gujar, A.R.; Ambre, N.V.

    .63 1.31 6.54 1.47 2.61 - 0.32 - 16.09 1.47 - - 90 HT (0-20) n = 340 Sukalbhat 40.88 1.47 41.47 1.17 1.47 0.88 0.58 1.76 - 0.29 - 9.41 0.58 - - 91 Surface n = 621 Mahartale 96.6 0.32 1.93 0.16 0.16 0.16 0.32 - - - - 0...

  3. Summary of Dissolved Concentration Limits

    International Nuclear Information System (INIS)

    Yueting Chen

    2001-01-01

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M and O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits

  4. Summary of Dissolved Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Yueting Chen

    2001-06-11

    According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based on the process models and chemical conditions and to produce solubility distributions or response surfaces applicable to the proposed repository. The results of this analysis and conceptual model will feed the performance assessment for Total System Performance Assessment--Site Recommendation (TSPA-SR) and Total System Performance Assessment--License Application (TSPA-LA), and to the Waste Form Degradation Process Model Report section on concentration limits.

  5. Installation package for concentrating solar collector panels

    Science.gov (United States)

    1978-01-01

    The concentrating solar collector panels comprise a complete package array consisting of collector panels using modified Fresnel prismatic lenses for a 10 to 1 concentrating ratio, supporting framework, fluid manifolding and tracking drive system, and unassembled components for field erection.

  6. Entropy concentration and the empirical coding game

    NARCIS (Netherlands)

    Grünwald, P.D.

    2008-01-01

    We give a characterization of maximum entropy/minimum relative entropy inference by providing two 'strong entropy concentration' theorems. These theorems unify and generalize Jaynes''concentration phenomenon' and Van Campenhout and Cover's 'conditional limit theorem'. The theorems characterize

  7. Nonimaging solar concentrator with uniform irradiance

    Science.gov (United States)

    Winston, Roland; O'Gallagher, Joseph J.; Gee, Randy C.

    2004-09-01

    We report results of a study our group has undertaken under NREL/DOE auspices to design a solar concentrator with uniform irradiance on a planar target. This attribute is especially important for photovoltaic concentrators.

  8. Relationship between bank ownership concentration on capital ...

    African Journals Online (AJOL)

    Relationship between bank ownership concentration on capital adequacy, liquidity, ... In this study we explore the effects of ownership concentration on the ... are material factors in explaining banks' behavior and their market performance.

  9. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  10. Oxygen Concentration Inside a Functioning Photosynthetic Cell

    OpenAIRE

    Kihara, Shigeharu; Hartzler, Daniel A.; Savikhin, Sergei

    2014-01-01

    The excess oxygen concentration in the photosynthetic membranes of functioning oxygenic photosynthetic cells was estimated using classical diffusion theory combined with experimental data on oxygen production rates of cyanobacterial cells. The excess oxygen concentration within the plesiomorphic cyanobacterium Gloeobactor violaceus is only 0.025 μM, or four orders of magnitude lower than the oxygen concentration in air-saturated water. Such a low concentration suggests that the first oxygenic...

  11. Relationship between silicon concentration and creatinine clearance

    International Nuclear Information System (INIS)

    Miura, Y.; Nakai, K.; Itoh, C.; Horikiri, J.; Sera, K.; Sato, M.

    1998-01-01

    Silicon levels in dialysis patients are markedly increasing. Using PIXE we determined the relationship between silicon concentration and creatinine clearance in 30 samples. Urine silicon concentration were significantly correlated to creatinine clearance (p<0.001). And also serum silicon concentration were significantly correlated to creatinine clearance (p<0.0001). (author)

  12. Color corrected Fresnel lens for solar concentration

    International Nuclear Information System (INIS)

    Kritchman, E.M.

    1979-01-01

    A new linear convex Fresnel lens with its groove side down is described. The design philosophy is similar to the highly concentrating two focal Fresnel lens but including a correction for chromatic aberration. A solar concentration ratio as high as 80 is achieved. For wide acceptance angles the concentration nears the theoretical maximum. (author)

  13. Effects of concentrated sunlight on organic photovoltaics

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Katz, Eugene A.; Hirsch, Baruch

    2010-01-01

    We report the effects of concentrated sunlight on key photovoltaic parameters and stability of organic photovoltaics (OPV). Sunlight collected and concentrated outdoors was focused into an optical fiber and delivered onto a 1 cm2 bulk-heterojunction cell. Sunlight concentration C was varied gradu...

  14. Method of enriching oil shale concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M

    1942-02-14

    The method is characterized by producing one concentrate first and then this concentrate, in water solution using suitable apparatus, is separated by settling into one heavier bottom portion, rich in mineral matter, and into a lighter slime containing concentrated organic substance.

  15. Probiotic Yoghurts From Ultrafiltered Concentrated Milk

    Directory of Open Access Journals (Sweden)

    Kozludzhova Siyka

    2015-12-01

    Full Text Available In this paper, yoghurts from ultrafiltered concentrated whole milk with a volume reduction ratio 0, 2 and 3 with three different probiotic yoghurt starters were obtained. Their physiological, microbiological and rheological properties were examined. The concentrated probiotic yoghurts had high concentration of viable cells of the probiotic strain Lactobacillus delbrueckii ssp. bulgaricus (over 1010cfu/cm3. For the preparation of concentrated probiotic yoghurts the most appropriate volume reduction ratio was 2. The probiotic yoghurts with starters MZ2 and 1CM had the best structure. The concentrated probiotic yoghurts with all starters are functional foods.

  16. Photovoltaic applications of Compound Parabolic Concentrator (CPC)

    Science.gov (United States)

    Winston, R.

    1975-01-01

    The use of a compound parabolic concentrator as field collector, in conjunction with a primary focusing concentrator for photovoltaic applications is studied. The primary focusing concentrator can be a parabolic reflector, an array of Fresnel mirrors, a Fresnel lens or some other lens. Silicon solar cell grid structures are proposed that increase efficiency with concentration up to 10 suns. A ray tracing program has been developed to determine energy distribution at the exit of a compound parabolic concentrator. Projected total cost of a CPC/solar cell system will be between 4 and 5 times lower than for flat plate silicon cell arrays.

  17. Nonimaging concentrators for solar thermal energy

    Science.gov (United States)

    Winston, R.; Gallagher, J. J.

    1980-03-01

    A small experimental solar collector test facility was used to explore applications of nonimaging optics for solar thermal concentration in three substantially different configurations: a single stage system with moderate concentration on an evacuated absorber (a 5.25X evacuated tube Compound Parabolic Concentrator or CPC), a two stage system with high concentration and a non-evacuated absorber (a 16X Fresnel lens/CPC type mirror) and moderate concentration single stage systems with non-evacuated absorbers for lower temperature (a 3X and a 6.5X CPC). Prototypes of each of these systems were designed, built and tested. The performance characteristics are presented.

  18. MARKET CONCENTRATION IN TURKISH JOURNALISM SECTOR

    Directory of Open Access Journals (Sweden)

    ADEM KALÇA

    2013-05-01

    Full Text Available Concentration is a situation in which market structure of a sector is controlled by a few firms. At the present time, many analyzing methods such as Herfindahl-Hirschman and N-Firm Concentration Indexes are used to determine market structure.According to market concentration indexes, higher concentration level means more monopolistic market structure, lower concentration level means more full competitive market structure. In this study concentration levels of media groups in Turkish journalism sector within the scope of traditional journalism and internet journalism was analyzed via N-Firm Concentration and H-H Indexes. As a result of the study, it’s seen that first four biggest media groups have monopolistic competition in internet journalism sector,and oligopol structure in traditional journalism sector. According to H-H index analyze, there is monopolistic competition in the sector.

  19. New method of design of nonimaging concentrators.

    Science.gov (United States)

    Miñano, J C; González, J C

    1992-06-01

    A new method of designing nonimaging concentrators is presented and two new types of concentrators are developed. The first is an aspheric lens, and the second is a lens-mirror combination. A ray tracing of three-dimensional concentrators (with rotational symmetry) is also done, showing that the lens-mirror combination has a total transmission as high as that of the full compound parabolic concentrators, while their depth is much smaller than the classical parabolic mirror-nonimaging concentrator combinations. Another important feature of this concentrator is that the optically active surfaces are not in contact with the receiver, as occurs in other nonimaging concentrators in which the rim of the mirror coincides with the rim of the receiver.

  20. Factors Affecting Tocopherol Concentrations in Soybean Seeds.

    Science.gov (United States)

    Carrera, Constanza S; Seguin, Philippe

    2016-12-21

    Soybean seeds contain several health-beneficial compounds, including tocopherols, which are used by the nutraceutical and functional food industries. Soybean tocopherol concentrations are, however, highly variable. Large differences observed in tocopherol concentrations among soybean genotypes together with the relatively simple biosynthetic pathway involving few genes support the feasibility of selecting for high-tocopherol soybean. Tocopherol concentrations are also highly influenced by environmental factors and field management. Temperature during seed filling and soil moisture appear to be the main factors affecting tocopherol concentrations; other factors such as soil fertility and solar radiation also affect concentrations and composition. Field management decisions including seeding date, row spacing, irrigation, and fertilization also affect tocopherols. Knowledge of factors affecting soybean tocopherols is essential to develop management strategies that will lead to the production of seeds with consistent target concentrations that will meet the needs of the nutraceutical and functional food industries.

  1. Causality Between Urban Concentration and Environmental Quality

    Directory of Open Access Journals (Sweden)

    Amin Pujiati

    2015-08-01

    Full Text Available Population is concentrated in urban areas can cause the external diseconomies on environment if it exceeds the carrying capacity of the space and the urban economy. Otherwise the quality of the environment is getting better, led to the concentration of population in urban areas are increasingly high. This study aims to analyze the relationship of causality between the urban concentration and environmental quality in urban agglomeration areas. The data used in the study of secondary data obtained from the Central Bureau of statistics and the City Government from 2000 to 2013. The analytical method used is the Granger causality and descriptive. Granger causality study results showed no pattern of reciprocal causality, between urban concentration and the quality of the environment, but there unidirectional relationship between the urban concentration and environmental quality. This means that increasing urban concentration led to decreased environmental quality.

  2. Target concentration intervention: beyond Y2K.

    Science.gov (United States)

    Holford, N H

    2001-01-01

    Target concentration intervention (TCI) is proposed as an alternative conceptual strategy to therapeutic drug monitoring (TDM). It is argued that the idea of a therapeutic range has limited the interpretation of measured drug concentrations and diminished the anticipated clinical benefit to patients by use of an oversimplified pharmacodynamic model. TCI on the other hand embraces pharmacokinetic and pharmacodynamic concepts and uses the idea of a target effect and associated target concentration to make rational individual dose decisions.

  3. Radon concentration in greehouses of Aomori Prefecture

    International Nuclear Information System (INIS)

    Iyogi, Takashi; Hisamatsu, Shun'ichi; Inaba, Jiro

    2001-01-01

    222 Rn causes a significant part of natural radiation dose to the general population. We previously surveyed 222 Rn concentrations in dwellings, and indoor and outdoor workplaces in Aomori Prefecture, and found geometric mean concentrations of 13, 22 and 4.4 Bq m -3 , respectively. The annual radiation dose rate of 4.3 mSv y -1 was estimated for people in the prefecture from these data. Since 222 Rn in the environment mainly originates from 226 Ra in the soil, that in cave is known to be higher than that in ordinary environments such as in buildings. Greenhouses are a possible place with high 222 Rn concentration, because of the soil exposed inside. However, the 222 Rn concentration in greenhouses has not yet been reported. We surveyed 222 Rn concentration in greenhouses of Aomori Prefecture. The 222 Rn concentration in 24 greenhouses at six locations in the prefecture were measured for approximately one year with passive Rn detectors using a polycarbonate film for counting α-rays, which could separate concentrations of 222 Rn from 220 Rn. Measurements of 222 Rn concentration and working level for one week carried out with active detectors to get equilibrium factors and the ratio of 222 Rn concentration in working time to non-working time in selected greenhouses. The geometric mean of 222 Rn concentrations in greenhouses was 13 Bq m -3 , and similar to that in dwellings. Significant seasonal variation was observed in 222 Rn concentrations. The geometric mean in June to September was 5.5 Bq m -3 , which was similar to that outside the greenhouses, while that in January to March was 19.5 Bq m -3 . These results showed that the 222 Rn concentration in greenhouses was comparable to that in dwellings. (author)

  4. Modeling sediment concentration of rill flow

    Science.gov (United States)

    Yang, Daming; Gao, Peiling; Zhao, Yadong; Zhang, Yuhang; Liu, Xiaoyuan; Zhang, Qingwen

    2018-06-01

    Accurate estimation of sediment concentration is essential to establish physically-based erosion models. The objectives of this study were to evaluate the effects of flow discharge (Q), slope gradient (S), flow velocity (V), shear stress (τ), stream power (ω) and unit stream power (U) on sediment concentration. Laboratory experiments were conducted using a 10 × 0.1 m rill flume under four flow discharges (2, 4, 8 and 16 L min-1), and five slope gradients (5°, 10°, 15°, 20° and 25°). The results showed that the measured sediment concentration varied from 87.08 to 620.80 kg m-3 with a mean value of 343.13 kg m-3. Sediment concentration increased as a power function with flow discharge and slope gradient, with R2 = 0.975 and NSE = 0.945. The sediment concentration was more sensitive to slope gradient than to flow discharge. The sediment concentration was well predicted by unit stream power (R2 = 0.937, NSE = 0.865), whereas less satisfactorily by flow velocity (R2 = 0.470, NSE = 0.539) and stream power (R2 = 0.773, NSE = 0.732). In addition, using the equations to simulate the measured sediment concentration of other studies, the result further indicated that slope gradient, flow discharge and unit stream power were good predictors of sediment concentration. In general, slope gradient, flow discharge and unit stream power seem to be the preferred predictors for estimating sediment concentration.

  5. Characterization and concentration of manganese ore waste

    International Nuclear Information System (INIS)

    Lima, Rosa Malena Fernandes; Pereira, Eder Esper; Reis, Erica Linhares; Silva, Glaucia Regina da

    2010-01-01

    In this work is presented the tests results of characterization and concentration by gravity and flotation methods carried out with a manganese sample waste. By optical microscopy, SEM/EDS and X-ray diffractometry were identified the Mn minerals spessartite (20%), tephroite (15%), rhodonite (5%), rhodochrosite and carbonates minerals (29%), opaque minerals and others (16%), micaceus minerals (6%) and quartz (4%). It was obtained Mn metallurgical recovery of 58% with Mn concentrate contents varying from 30 to 32.5%. The concentrates SiO_2 contents of flotation were until 1.5% smaller than those contents of gravity method concentrates. (author)

  6. A point focusing double parabolic trough concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Murphree, Quincy C. [Kentucky Mountain Bible College, Vancleve, KY (United States)

    2001-07-01

    This article shows that a point focusing solar concentrator can be made from two reflective parabolic troughs, a primary and a secondary, by orienting their longitudinal axes in perpendicular directions and separating them by the difference of their focal lengths along the optical axis. This offers a new alternative to the conventional 3-D paraboloidal concentrator permitting more flexibility in designs for applications requiring high concentrations. Both advantages and disadvantages are discussed. The intensity concentration ratio distribution is calculated in the focal plane and has elliptically shaped contours due to the inherent compensation of errant rays by the concave secondary. The ratio of the major to minor axes was 2.61 for the case considered, resulting in a concentration {approx}2.61 times that of a comparable concentrator without the compensation afforded by a concave secondary. Still, geometrical constraints limit the concentration to about 2000 suns for mirror quality errors of 5 mr. Optimisation of the compensation effect holds potential for improved performance for other concentrator designs. Finally, the functional dependence of the peak concentration and shading factor upon design parameters are presented. (Author)

  7. Tritium concentrations in tree ring cellulose

    International Nuclear Information System (INIS)

    Kaji, Toshio; Momoshima, Noriyuki; Takashima, Yoshimasa.

    1989-01-01

    Measurements of tritium (tissue bound tritium; TBT) concentration in tree rings are presented and discussed. Such measurement is expected to provide a useful means of estimating the tritium level in the environment in the past. The concentration of tritium bound in the tissue (TBT) in a tree ring considered to reflect the environmental tritium level in the area at the time of the formation of the ring, while the concentration of tritium in the free water in the tissue represents the current environmental tritium level. First, tritium concentration in tree ring cellulose sampled from a cedar tree grown in a typical environment in Fukuoka Prefecture is compared with the tritium concentration in precipitation in Tokyo. Results show that the year-to-year variations in the tritium concentration in the tree rings agree well with those in precipitation. The maximum concentration, which occurred in 1963, is attibuted to atmospheric nuclear testing which was performed frequently during the 1961 - 1963 period. Measurement is also made of the tritium concentration in tree ring cellulose sampled from a pine tree grown near the Isotope Center of Kyushu University (Fukuoka). Results indicate that the background level is higher probably due to the release of tritium from the facilities around the pine tree. Thus, measurement of tritium in tree ring cellulose clearly shows the year-to-year variation in the tritium concentration in the atmosphere. (N.K.)

  8. Continuous measurements of outdoor radon concentrations

    International Nuclear Information System (INIS)

    Iida, T.; Ikebe, Y.; Suzuki, K.; Ueno, K.; Komura, K.; Kato, I.; Jin Yihe

    1993-01-01

    The authors studied and developed an electrostatic 222 Rn monitor and have measured continuously outdoor radon ( 222 Rn) concentrations at Nagoya University since 1985. Four 222 Rn monitors were newly constructed to measure outdoor 222 Rn concentrations at other locations. The 222 Rn concentrations at Nagoya and Kasugai show a clear diurnal variation in autumn, and a seasonal pattern of a spring-summer minimum and a autumn-winter maximum. The results at Toki are the same pattern as that at Nagoya except spring. The concentrations at Kanazawa show a slight seasonal variation. A clear diurnal variation is observed in summer. (4 figs.)

  9. Alignment method for parabolic trough solar concentrators

    Science.gov (United States)

    Diver, Richard B [Albuquerque, NM

    2010-02-23

    A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

  10. Interstitial adenosine concentration is increased by dipyridamole

    International Nuclear Information System (INIS)

    Gorman, M.W.; Wangler, R.D.; DeWitt, D.F.; Wang, C.Y.; Bassingthwaighte, J.B.; Sparks, H.V.

    1986-01-01

    The authors used the multiple indicator dilution technique to observe the capillary transport of adenosine (ADO) in isolated guinea pig hearts. Radiolabelled albumin, sucrose and ADO were injected on the arterial side and measured in venous samples collected during the following 20 seconds. Transport parameters calculated from these data include permeability-surface area products (PS) for transendothelial diffusion, endothelial cell (EC) uptake at the lumenal and ablumenal membranes, and EC metabolism. With simultaneous measurements of arterial and venous ADO concentrations and flow, the authors calculated the steady-state interstitial fluid (ISF) ADO concentration. Under control conditions the venous ADO concentration was 7.1 +/- 2.8 nM. The calculated ISF concentration depends on whether they assume the venous ADO comes from the ISF, or directly from ECs. These ISF concentrations are 25 +/- 12 nM and 9.8 +/- 4.0 nM, respectively. During dipyridamole infusion (10 uM) the EC transport parameters became nearly zero. Venous and ISF ADO concentrations increased to 33 +/- 8.9 nM and 169 +/- 42 nM, respectively. The authors conclude that the ISF ADO concentration is 1.5-4 fold higher than the venous concentration at rest, and the ISF concentration increases greatly with dipyridamole

  11. HYPOLIPEMIC THERAPY AND LOW SERUM CHOLESTEROL CONCENTRATION

    Directory of Open Access Journals (Sweden)

    Vladmila Bojanic

    2004-01-01

    Full Text Available Low concentration of plasma lipoproteins (hypolipoproteinemia presents decreasing concentrations of all or particular lipids components. Classification of hypolipoproteinemia (hypoLP divides them into: primary (hereditary and secondary. Primary hipoLP are rare diseases and their main characteristic is disorder of apolipoproteins synthesis, which leads to low serum cholesterol concentration. Secondary hipoLP are presented in many diseases. They have diagnostic, prognostic significance and present good therapeutic marker. However, modern therapeutic approaches for aggressive lipid lowering pointed out many questions about physiological limits for cholesterol lowering. These approaches, also, open many questions about consequences of low serum concentration of total cholesterol and triglicerides.

  12. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    Science.gov (United States)

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

  13. Measurements of natural 41Ca concentrations

    International Nuclear Information System (INIS)

    Steinhof, A.

    1989-05-01

    Atomic mass spectroscopic examinations on 41 Ca were carried out in the UNILAC accelerator. A sensitivity of about 10 -15 was achieved. This would allow the measurement of present natural 41 Ca concentrations as soon as the problem of the transmission determination is solved. In this respect suggestions were worked out and their feasibility discussed. The detection of 41 Ca-ions is especially free of background when high UNILAC-energies are applied. An estimation showed a background level corresponding with a 41 Ca concentration of less then 10 -17 referred to 40 Ca. Besides an independent concept for the electromagnetic concentration of 41 Ca with variable concentration factors was developed. After being concentrated up to 50 respectively 25 times the initial concentration in the GSI mass separator, the 41 Ca concentration of three recent deer bones found in the Odenwald was measured by atomic mass spectroscopy in the 14UD-Pelletron Tandem in Rehovot (Israel). The measured 41 Ca concentrations ranged between 10 -14 to 10 -13 with consideration of the concentration factor. A theoretical study of the 41 Ca production in the earth's surface based on cosmic radiation illustrates the influence of trace elements on the neutron flux and thus on the 41 Ca production. This influence might be a possible explanation for the observed amplitude of variation of the 41 Ca concentration in recent bones which are of decisive importance for the feasibility of 41 Ca-related dating. In this work a method is suggested that does not depend on the amplitude of variation mentioned above and which would allow the determination of the erosion rate of rocks by its 41 Ca concentrations. (orig./HP) [de

  14. Use of mineral magnetic concentration data as a particle size proxy: a case study using marine, estuarine and fluvial sediments in the Carmarthen Bay area, South Wales, U.K.

    Science.gov (United States)

    Booth, C A; Walden, J; Neal, A; Smith, J P

    2005-07-15

    Compositional (non-magnetic) data can correlate strongly with particle size, which deems it appropriate as a particle size proxy and, therefore, a reliable means of normalising analytical data for particle size effects. Previous studies suggest magnetic concentration parameters represent an alternative means of normalising for these effects and, given the speed, low-cost and sensitivity of the measurements may, therefore, offer some advantages over other compositional signals. In this work, contemporary sediments from a range of depositional environments have been analysed with regard to their mineral magnetic concentration and textural characteristics, to observe if the strength and nature of the relationship identified in previous studies is universal. Our data shows magnetic parameters (chi(LF), chi(ARM) and SIRM) possess contrasting relationships with standard textural parameters for sediment samples collected from marine (Carmarthen Bay), estuarine (Gwendraeth Estuary) and fluvial (Rivers Gwendraeth Fach and Gwendraeth Fawr) settings. Magnetic concentrations of sediments from both the marine and estuarine environments are highly influenced by the magnetic contribution of finer particle sizes; Gwendraeth Fawr River sediments are influenced by the magnetic contribution of coarser particle sizes, while sediments from the Gwendraeth Fach River are not influenced significantly by any variations in textural properties. These results indicate mineral magnetic measurements have considerable potential as a particle size proxy for particular sedimentary environments, which in certain instances could be useful for geochemical, sediment transport, and sediment provenance studies. However, the data also highlight the importance of fully determining the nature of the relationship between sediment particle size and magnetic properties before applying mineral magnetic data as a particle size proxy.

  15. 21 CFR 155.191 - Tomato concentrates.

    Science.gov (United States)

    2010-04-01

    ... Tomato concentrates. (a) Identity—(1) Definition. Tomato concentrates are the class of foods each of... greater in length. (c) Blemishes, such as dark brown or black particles (specks)—not more than four exceed...; place a U.S. No. 12 screen (1.68 millimeters (0.066 inch) openings) over the sink drain; transfer the...

  16. Influence of surfactant concentration on nanohydroxyapatite growth

    Indian Academy of Sciences (India)

    Nanohydroxyapatite particles with different morphologies were synthesized through a microwave coupled hydrothermal method using CTAB as a template. A successful synthesis of nanosized HAP spheres, rods and fibres is achieved through this method by controlling the concentration of the surfactant. The concentration ...

  17. Stress Concentration around Holes in Anistropic Sheets

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    The formulation of stress concentration problems of plane anisotropic elasticity in terms of integral equations is discussed. First the singular solutions of a concentrated force and a dislocation are formulated so that they remain valid in the case of double roots. The distribution of singularit...

  18. Luminescent Solar Concentrators with Fibre Geometry

    NARCIS (Netherlands)

    Edelenbosch, O.Y.; Fisher, M.; Patrignani, L.; Sark, W.G.J.H.M. van; Chatten, A.J.

    2013-01-01

    The potential of a fibre luminescent solar concentrator has been explored by means of both analytical and ray-tracing techniques. Coated fibres have been found to be more efficient than homogeneously doped fibres, at low absorption. For practical fibres concentration is predicted to be linear

  19. MCB-2 concentration meter for boric acid

    International Nuclear Information System (INIS)

    Lisecki, W.

    1978-01-01

    The principles are explained of the thermal neutron absorption method for monitoring boric acid concentration in the WWER type reactor coolant. The design principles and the characteristics of four variants are described of the MSB-2 type boric acid concentration monitor developed by IBJ. (B.S.)

  20. Postmortem Femoral Blood Concentrations of Risperidone

    DEFF Research Database (Denmark)

    Linnet, Kristian; Johansen, Sys Stybe

    2014-01-01

    Postmortem femoral blood concentrations of the antipsychotic drug risperidone and the active metabolite 9-hydroxyrisperidone were determined by an achiral LC-MS/MS method in 38 cases. The cause of death was classified as unrelated to risperidone in 30 cases, in which the sum of the concentration ...

  1. Universal distortion-free entanglement concentration

    International Nuclear Information System (INIS)

    Matsumoto, Keiji; Hayashi, Masahito

    2007-01-01

    We propose a new protocol of universal entanglement concentration, which converts many copies of an unknown pure state to an exact maximally entangled state. The yield of the protocol, which is outputted as a classical information, is probabilistic, and achieves the entropy rate with high probability, just as nonuniversal entanglement concentration protocols do

  2. Recalculation of measured fuel nuclide concentrations

    International Nuclear Information System (INIS)

    Moeller, W.

    1984-01-01

    The concentrations and concentration ratios of heavy fuel nuclides determined in the Central Institute for Nuclear Research Rossendorf on the basis of destructive burnup measurements are compared with the results of microburnup calculations. The possibility is discussed to improve the results by taking into account the spectral characteristics at the positions of the measuring samples. (author)

  3. Cream concentrated latex for foam rubber products

    Science.gov (United States)

    Suksup, R.; Imkaew, C.; Smitthipong, W.

    2017-12-01

    Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

  4. Filterability and Sludge Concentration in Membrane Bioreactors

    NARCIS (Netherlands)

    Lousada-Ferreira, M.

    2011-01-01

    The Thesis entitled “Filterability and Sludge Concentration in Membrane Bioreactors” aims at explaining the relation between Mixed Liquid Suspended Solids (MLSS) concentration, the amount of solids in the wastewater being treated, also designated as sludge, and filterability, being the ability of

  5. Uranium concentrations in fossils measured by SIMS

    International Nuclear Information System (INIS)

    Uyeda, Chiaki; Okano, Jun

    1988-01-01

    Semiquantitative analyses of uranium in fossil bones and teeth were carried out by SIMS. The results show a tendency that uranium concentrations in the fossils increase with the ages of the fossils. It is noticed that fossil bones and teeth having uranium concentration of more than several hundred ppm are not rare. (author)

  6. Atmospheric relative concentrations in building wakes

    International Nuclear Information System (INIS)

    Ramsdell, J.V. Jr.; Simonen, C.A.; Smyth, S.B.

    1995-05-01

    This report documents the ARCON95 computer code developed for the U.S. Nuclear Regulatory Commission Office of Nuclear Regulatory Research for use in control room habitability assessments. The document includes a user's guide to the code, a description of the technical basis for the code, and a programmer's guide to the code. The ARCON95 code uses hourly meteorological data and recently developed methods for estimating dispersion in the vicinity of buildings to calculate relative concentrations at control room air intakes that would be exceeded no more five percent of the time. These concentrations are calculated for averaging periods ranging from one hour to 30 days in duration. Relative concentrations calculated by ARCON95 are significantly lower than concentrations calculated using the currently accepted procedure when winds are less than two meters per second. For higher wind speeds, ARCON95 calculates about the same concentrations as the current procedure

  7. Effect of paracentesis on ocular cloxacillin concentration

    International Nuclear Information System (INIS)

    Salminen, L.

    1978-01-01

    The effect of interior chamber puncture on cloxacillin concentration in the rabbit eye after intravenous injection was studied using a radioactive tracer method. The enhancement in drug concentration caused by paracentesis was most immediate and significant in the iris-ciliary body preparation. It was soon followed by high cloxacillin concentration in the aqueous humour, which contributed to elevated cloxacillin levels in the cornea, lens and anterior vitreous body, when compared to normal material. Contrary to normal eyes, cloxacillin concentration in the cornea of the punctured eyes was higher than in the limbal area. The morphological changes occurring after paracentesis are discussed. The breakdown of the hydrodynamic equilibrium in the eye, suggested as the only change after paracentesis by Raviola (1974), cannot merely explain the cloxacillin concentration changes measured in the punctured eye. (author)

  8. Current Status of Concentrator Photovoltaic (CPV) Technology

    Energy Technology Data Exchange (ETDEWEB)

    Philipps, Simon P. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Bett, Andreas W. [Fraunhofer Inst. for Solar Energy Systems ISE, Freiburg (Germany); Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kurtz, Sarah [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-12-01

    This report summarizes the status of the concentrator photovoltaic (CPV) market and industry as well as current trends in research and technology. This report is intended to guide research agendas for Fraunhofer ISE, the National Renewable Energy Laboratory (NREL), and other R&D organizations. Version 1.1 of this report includes recent progress in CPV. The recent record module efficiency of 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve. 38.9% at Concentrator Standard Test Conditions (CSTC) is an impressive result, demonstrating the continuing opportunity for CPV technology to improve.

  9. Obtain of uranium concentrates from fertil liquids

    International Nuclear Information System (INIS)

    Narvaez Castillo, W.A.

    1992-01-01

    This research tried to encounter the form to remove uranium from the rock in the best way, for that it was used different process like leaching, extraction, concentration and precipitation. To leach the mineral was chosen basic leaching, using a mixture of carbonate-sodium bicarbonate, this method is more adequated for the basic nature of the mineral. In extraction was used specific uranium ionic interchanges, so was chosen a tertiary amine like Alamina 336. The concentration phase is intimately binding with the extraction by ionic interchange, for the capability of resine's extraction to obtain concentrated liquids. When the liquids were obtained with high concentration of uranium in the same time were purified and then were precipitated, for that we employed a precipitant agent like: Sodium hydroxide, Amonium hydroxide, Magnesium hydroxide, Hydrogen peroxide and phosphates. With all concentrates we obtain the YELLOW CAKE

  10. The concentrations of uranium in marine organisms

    Energy Technology Data Exchange (ETDEWEB)

    Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki [National Inst. of Radiological Sciences, Hitachinaka, Ibaraki (Japan). Laboratory for Radioecology

    2000-07-01

    Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10{sup 3}, comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10{sup 2}. (author)

  11. The concentrations of uranium in marine organisms

    International Nuclear Information System (INIS)

    Matsuba, Mitsue; Ishii, Toshiaki; Nakahara, Motokazu; Nakamura, Ryoichi; Watabe, Teruhisa; Hirano, Shigeki

    2000-01-01

    Determination of uranium in sixty-one species of marine organisms was carried out by inductively coupled plasma mass spectrometry to obtain concentration factors and to estimate the internal radiation dose. The concentrations of uranium in soft tissues of marine animals were ranged from 0.077 to 5040 ng/g wet wt. Especially, the branchial heart of cephalopod molluscs showed the specific accumulation of uranium. The concentration factor of the branchial heart of Octopus vulgaris, which indicated the highest value, was calculated to be about 1.6 x 10 3 , comparing with that (3.1 ng/ml) in coastal seawaters of Japan. The concentrations of uranium in hard tissues of marine invertebrates such as clam and sea urchin were similar to those in soft tissues. In contrast, hard tissues like bone, scale, fin, etc. of fishes showed much higher concentrations of uranium than soft tissues like muscle. The concentrations of uranium of twenty-two species of algae were ranged from 2 to 310 ng/g wet wt. Particularly, the brown alga Undaria pinnatifida showed the highest value of the uranium content in the algae and its concentration factor was calculated to be 10 2 . (author)

  12. Intrapulmonary concentration of enrofloxacin in healthy calves

    Science.gov (United States)

    OTOMARU, Konosuke; HIRATA, Masaya; IKEDO, Tomonobu; HORINOUCHI, Chie; NOGUCHI, Michiko; ISHIKAWA, Shingo; NAGATA, Shun-ichi; HOBO, Seiji

    2015-01-01

    To determine the intrapulmonary concentration of enrofloxacin (ERFX) in calves, plasma, bronchoalveolar lavage fluid (BALF) and alveolar cells samples were obtained from clinically healthy calves. Four clinically healthy calves were administered a single dose of ERFX (5 mg/kg) by subcutaneous injection. Samples of plasma were obtained for each subjects at 0 (before administration), 1 and 2 hr after administration of ERFX. Samples of BALF were obtained from each subject at 0, 1 and 2 hr after administration of ERFX. This examination was conducted two times, one week apart. The mean EFRX concentrations in plasma at 1 and 2 hr after administration were l.23 and 1.29 µg/ml, respectively. The mean EFRX concentrations in pulmonary epithelial lining fluid (ELF) at 1 and 2 hr after administration 8.53 µg/ml and 9.42 µg/ml, respectively. The mean ERFX concentrations of alveolar cells in BALF at 1 and 2 hr after administration were 4.04 µg/ml and 5.19 µg/ml, respectively. These results suggest that the ERFX concentrations in ELF and alveolar cells concentrations in BALF at 1 and 2 hr after administration were higher than the plasma concentrations. PMID:26668174

  13. Revealing source signatures in ambient BTEX concentrations

    International Nuclear Information System (INIS)

    Zalel, Amir; Yuval; Broday, David M.

    2008-01-01

    Management of ambient concentrations of Volatile Organic Compounds (VOCs) is essential for maintaining low ozone levels in urban areas where its formation is under a VOC-limited regime. The significant decrease in traffic-induced VOC emissions in many developed countries resulted in relatively comparable shares of traffic and non-traffic VOC emissions in urban airsheds. A key step for urban air quality management is allocating ambient VOC concentrations to their pertinent sources. This study presents an approach that can aid in identifying sources that contribute to observed BTEX concentrations in areas characterized by low BTEX concentrations, where traditional source apportionment techniques are not useful. Analysis of seasonal and diurnal variations of ambient BTEX concentrations from two monitoring stations located in distinct areas reveal the possibility to identify source categories. Specifically, the varying oxidation rates of airborne BTEX compounds are used to allocate contributions of traffic emissions and evaporative sources to observed BTEX concentrations. - BTEX sources are identified from temporal variations of ambient concentration

  14. Oxygen concentration inside a functioning photosynthetic cell.

    Science.gov (United States)

    Kihara, Shigeharu; Hartzler, Daniel A; Savikhin, Sergei

    2014-05-06

    The excess oxygen concentration in the photosynthetic membranes of functioning oxygenic photosynthetic cells was estimated using classical diffusion theory combined with experimental data on oxygen production rates of cyanobacterial cells. The excess oxygen concentration within the plesiomorphic cyanobacterium Gloeobactor violaceus is only 0.025 μM, or four orders of magnitude lower than the oxygen concentration in air-saturated water. Such a low concentration suggests that the first oxygenic photosynthetic bacteria in solitary form could have evolved ∼2.8 billion years ago without special mechanisms to protect them against reactive oxygen species. These mechanisms instead could have been developed during the following ∼500 million years while the oxygen level in the Earth's atmosphere was slowly rising. Excess oxygen concentrations within individual cells of the apomorphic cyanobacteria Synechocystis and Synechococcus are 0.064 and 0.25 μM, respectively. These numbers suggest that intramembrane and intracellular proteins in isolated oxygenic photosynthetic cells are not subjected to excessively high oxygen levels. The situation is different for closely packed colonies of photosynthetic cells. Calculations show that the excess concentration within colonies that are ∼40 μm or larger in diameter can be comparable to the oxygen concentration in air-saturated water, suggesting that species forming colonies require protection against reactive oxygen species even in the absence of oxygen in the surrounding atmosphere. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. Soil dioxin concentrations in Baden-Wuerttemberg

    International Nuclear Information System (INIS)

    Wolf, D.

    1993-01-01

    Soil dioxin levels in Baden-Wuerttemberg are generally low. Where high dioxin concentrations have been reported like in Rastatt, Rheinfelden, Crailsheim-Maulach and Eppingen these phenomena are local. Already at less than 100 metres distance, drastically lower concentrations are measured. At 1500 to 2000 metres distance the values are back to the ordinary background level. A programme for detecting sources of emission in the entire state revealed no further sites of heavy contamination. For this assessment of soil dioxin concentrations in Baden-Wuerttemberg 1275 soil samples were used, which is a vast amount also in comparison with nation-wide surveys. The average dioxin content in farmland is about 1 ng I-TEq/kg m T . Soil dioxin concentrations are the higher the greater the density of settlements and industry. In cities they are about three to five times higher than the ubiquitous background concentration. The highest concentrations measured were 5-20 ng I-TE/kg in garden soils in cities. Sewage sludge may be a significant source of dioxin contamination for farmland, far beyond the ubiquitous background concentration. Automobile exhaust gas caused higher soil contamination within 10 m along both sides of the roads as a function of traffic. Because scavengers in gasoline are now prohibited and catalysts are becoming more and more common the rate of additional dioxin and furan contamination due to traffic will decrease. Currently, traffic-related emissions in Baden-Wuerttemberg are well below 2 g I-TEq. (orig./EF) [de

  16. Hydrophobicity and charge shape cellular metabolite concentrations.

    Directory of Open Access Journals (Sweden)

    Arren Bar-Even

    2011-10-01

    Full Text Available What governs the concentrations of metabolites within living cells? Beyond specific metabolic and enzymatic considerations, are there global trends that affect their values? We hypothesize that the physico-chemical properties of metabolites considerably affect their in-vivo concentrations. The recently achieved experimental capability to measure the concentrations of many metabolites simultaneously has made the testing of this hypothesis possible. Here, we analyze such recently available data sets of metabolite concentrations within E. coli, S. cerevisiae, B. subtilis and human. Overall, these data sets encompass more than twenty conditions, each containing dozens (28-108 of simultaneously measured metabolites. We test for correlations with various physico-chemical properties and find that the number of charged atoms, non-polar surface area, lipophilicity and solubility consistently correlate with concentration. In most data sets, a change in one of these properties elicits a ~100 fold increase in metabolite concentrations. We find that the non-polar surface area and number of charged atoms account for almost half of the variation in concentrations in the most reliable and comprehensive data set. Analyzing specific groups of metabolites, such as amino-acids or phosphorylated nucleotides, reveals even a higher dependence of concentration on hydrophobicity. We suggest that these findings can be explained by evolutionary constraints imposed on metabolite concentrations and discuss possible selective pressures that can account for them. These include the reduction of solute leakage through the lipid membrane, avoidance of deleterious aggregates and reduction of non-specific hydrophobic binding. By highlighting the global constraints imposed on metabolic pathways, future research could shed light onto aspects of biochemical evolution and the chemical constraints that bound metabolic engineering efforts.

  17. Aspects of reduction clorination of pyrochlore concentrates

    International Nuclear Information System (INIS)

    Gameiro, D.H.; Brocchi, E.A.

    1985-01-01

    Reduction chlorination experiments were carried out with two different Brazilian pyrochlore concentrates in order to evaluate the effects of some variables on the extent of niobium pentoxide gaseification as well as to compare the behavior of concentrate under the same chlorination conditions. The pyrochlore concentrates from Araxa (MG) and Catalao (GO), Brazil, were submitted to X ray diffraction and X ray fluorescence analysis for determining their chemical compositions. Kinetic curves were obtained with the main variables being temperature and percentage of reducing agent. Analysis of the condensed material in terms of Nb 2 O 5 indicated that chlorination can be used to produce niobium pentoxide. (Author) [pt

  18. Theoretical modelling of solar dish concentrator

    International Nuclear Information System (INIS)

    Yaaseen Rafeeu; Mohd Zainal Abidin Abdul Kadir; Senan Mohamed Abdulla; Nor Mariah Adam

    2009-01-01

    Full text: Concentrating solar power (CSP) technologies could be one of the major contributor to worlds future energy needs and which would be cheap and clean sources of energy. This would improve energy utilization, higher conversion efficiency with reliable and affordable supply of electricity to the public. The proposed approach is using different size and depth of solar dish concentrators to improve solar fraction using the aluminium foil as reflector. In this paper, different measurement of solar concentrators is investigated and aims to aims to introducing an improved methodology for solar fraction on incoming solar energy in wet climate. (author)

  19. Concentrated sunlight for organic solar cells

    DEFF Research Database (Denmark)

    Tromholt, Thomas

    2010-01-01

    . A high solar intensity study of inverted P3HT:PCBM solar cells is presented. Performance peak positions were found to be in the range of 1-5 suns, with smaller cells peaking at higher solar concentrations. Additionally, concentrated sunlight is demonstrated as a practical tool for accelerated stability...... were degraded resulting in acceleration factors in the range of 19-55. This shows that concentrated sunlight can be used as qualitatively to determine the lifetime of polymers under highly accelerated conditions....

  20. Plasma fibronectin concentrations in morbidly obese patients

    DEFF Research Database (Denmark)

    Dejgaard, A; Andersen, T; Christoffersen, Pernille Yde

    1984-01-01

    Plasma fibronectin concentrations and liver morphology were investigated in 45 morbidly obese subjects (median overweight 88%) and in 42 normal weight controls, matched for sex and age. A significantly (P less than 0.01) raised plasma fibronectin concentration (median 464 mg/l, range 276-862 mg...... in their liver biopsies (r = 0.33, P less than 0.05). Significantly (P less than 0.05) elevated plasma fibronectin concentrations even in obese subjects without hepatic fatty change indicate that liver fat accumulation is no prerequisite of the obesity-related elevation of plasma fibronectin. Raised plasma...

  1. Indoor radon concentration forecasting in South Tyrol

    International Nuclear Information System (INIS)

    Verdi, L.; Weber, A.; Stoppa, G.

    2004-01-01

    In this paper a modern statistical technique of multivariate analysis is applied to an indoor radon concentration database. Several parameters are more or less significant in determining the radon concentration inside a building. The elaboration of the information available on South Tyrol makes it possible both to identify the statistically significant variables and to build up a statistical model that allows us to forecast the radon concentration in dwellings, when the values of the same variables involved are given. The results confirm the complexity of the phenomenon. (authors)

  2. Sucralfate significantly reduces ciprofloxacin concentrations in serum.

    OpenAIRE

    Garrelts, J C; Godley, P J; Peterie, J D; Gerlach, E H; Yakshe, C C

    1990-01-01

    The effect of sucralfate on the bioavailability of ciprofloxacin was evaluated in eight healthy subjects utilizing a randomized, crossover design. The area under the concentration-time curve from 0 to 12 h was reduced from 8.8 to 1.1 micrograms.h/ml by sucralfate (P less than 0.005). Similarly, the maximum concentration of ciprofloxacin in serum was reduced from 2.0 to 0.2 micrograms/ml (P less than 0.005). We conclude that concurrent ingestion of sucralfate significantly reduces the concentr...

  3. Luminescent solar concentrators with fiber geometry.

    Science.gov (United States)

    Edelenbosch, Oreane Y; Fisher, Martyn; Patrignani, Luca; van Sark, Wilfried G J H M; Chatten, Amanda J

    2013-05-06

    The potential of a fibre luminescent solar concentrator has been explored by means of both analytical and ray-tracing techniques. Coated fibres have been found to be more efficient than homogeneously doped fibres, at low absorption. For practical fibres concentration is predicted to be linear with fibre length. A 1 m long, radius 1 mm, fibre LSC doped with Lumogen Red 305 is predicted to concentrate the AM1.5 g spectrum up to 1100 nm at normal incidence by ~35 x. The collection efficiency under diffuse and direct irradiance in London has been analysed showing that, even under clear sky conditions, in winter the diffuse contribution equals the direct.

  4. Determination of particle concentrations in multitemperature plasmas

    International Nuclear Information System (INIS)

    Richley, E.; Tuma, D.T.

    1982-01-01

    The use of the multitemperature Saha equation (MSE) of Prigogine 1 and Patapov 2 for calculating particle concentrations in plasmas is shown to be an invalid procedure. Errors greater than one order of magnitude in the electron density in high-pressure argon and nitrogen electric arc plasmas can be easily incurred by using the multitemperature Saha equation. The alternative kinetic method for calculating concentrations is shown to be based on firm concepts. Simpliying procedures and computational techniques for calculating concentrations with the kinetic method are illustrated with examples

  5. Computational algorithm for molybdenite concentrate annealing

    International Nuclear Information System (INIS)

    Alkatseva, V.M.

    1995-01-01

    Computational algorithm is presented for annealing of molybdenite concentrate with granulated return dust and that of granulated molybdenite concentrate. The algorithm differs from the known analogies for sulphide raw material annealing by including the calculation of return dust mass in stationary annealing; the latter quantity varies form the return dust mass value obtained in the first iteration step. Masses of solid products are determined by distribution of concentrate annealing products, including return dust and benthonite. The algorithm is applied to computations for annealing of other sulphide materials. 3 refs

  6. Body and Gender in Nazi Concentration Camps

    Directory of Open Access Journals (Sweden)

    Bożena Karwowska

    2009-01-01

    Full Text Available The article Body and Gender in Nazi Concentration Camps is an attempt to discuss difficult issues of human sexuality and sexually marked behaviors in the context of the concentration camps, and their descriptions in the memoirs of the survivors. Using notions and concepts of the so called "black American feminism" the author (referring extensively to books by Stanisław Grzesiuk and Zofia Romanowiczowa shows how in the concentration camp the human body became the only space of a relative privacy of the prisoner. At the same time the body becomes a territory on which all - both biological and socially constructed - human fates cross.

  7. Maximum permissible concentrations and negligible concentrations for antifouling substances. Irgarol 1051, dichlofluanid, ziram, chlorothalonil and TCMTB

    NARCIS (Netherlands)

    Wezel AP van; Vlaardingen P van; CSR

    2001-01-01

    This report presents maximum permissible concentrations and negligible concentrations that have been derived for various antifouling substances used as substitutes for TBT. Included here are Irgarol 1051, dichlofluanide, ziram, chlorothalonil and TCMTB.

  8. Experimental investigations into low concentrating line axis solar concentrators for CPV applications

    OpenAIRE

    Singh, H; Sabry, M; Redpath, DAG

    2016-01-01

    Solar photovoltaic conversion systems with integrated, low concentration ratio, non-imaging reflective concentrators, could be on south facing building roofs used to generate power at a lower cost than currently available proprietary systems. The experimental investigation presented by this research provides information on the optical and energy conversion characteristics of two geometrically equivalent non-imaging concentrators; a compound parabolic concentrator and a V-trough reflector. The...

  9. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    Azevedo, M.F. de.

    1986-01-01

    The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

  10. Characterization of high concentration dust generator

    International Nuclear Information System (INIS)

    Shimura, Toichiro; Yokochi, Akira

    1999-01-01

    This paper describes the development of fluidized bed type high concentration dust generator that keeps for long period dust concentration range of about 10 mg/m 3 for the study of working place monitoring system and evaluation of respirator. The generator is keeping constant powder in fluidized bed for keeping the dust concentration. It is necessary to keep constant feeding rate of powder in order to keep the quantity of dust in the fluidized bed. Our generator enables to obtain constant feeding rate by a screw feeder and by using mixed powder with fluidising particles (glass beads) before feeding. The generator produces high concentration dust of 11.3 mg/m 3 ± 1.0 mg/m 3 for about 5 hours and keeps the dust size 4.2-4.6 μm in mass median aerodynamic diameter with reasonable reproducibility. (author)

  11. Arctic and Southern Ocean Sea Ice Concentrations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly sea ice concentration for Arctic (1901 to 1995) and Southern oceans (1973 to 1990) were digitized on a standard 1-degree grid (cylindrical projection) to...

  12. Indoor radon concentrations in Vushtrri, Kosovo

    International Nuclear Information System (INIS)

    Xhafa, B.; Jonuzaj, A.; ); Bekteshi, S.; Ahmetaj, S.; Kabashi, S.; )

    2009-01-01

    Indoor air radon concentration was measured by exposing trac ketch detectors in the two elementary schools, one high school, a kindergarten and the hospital in the city of Vushtrri. Measurements were performed with the radon monitor PRM-145, which uses alpha scintillation cells and serves to determine the current concentration of radon. The results we obtained are in the range between the average values of radon for the interior spaces, and values that pose a potential risk for lung cancer. Measuring the concentration of radon was done in total of 34 rooms and came up with values which are between 28Bqm -3 and 398Bqm -3 . In order to reduce the concentration of radon, we have built a ventilation pump, then we performed repeated measurements and finally came with results between 130-145Bqm -3 .

  13. Advancing Concentrating Solar Power Research (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP). This fact sheet summarizes how NREL is advancing CSP research.

  14. ISLSCP II Globalview: Atmospheric CO2 Concentrations

    Data.gov (United States)

    National Aeronautics and Space Administration — The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that were created...

  15. Radiometers for radon concentration in air

    International Nuclear Information System (INIS)

    Bartak, J.; Machaj, B.; Pienkos, J.P.

    2002-01-01

    Constant grow of science and technology stimulates development of new improved measuring tools. New measuring demand arise also in radon concentration measurements. Varying rock stress and rock cracks influencing radon emanation encouraged research aimed at use of this phenomenon to predict crumps of mine formation among others based on variation of radon emanation. A measuring set was developed in the Institute of Nuclear Chemistry and Technology enabling long term monitoring of radon concentration in mine bore-hole. The set consists probe and probe controller. Detection threshold of the probe is 230 Bq/m 3 . The set can operate in the environment with methane explosion hazard. A radiometer employing Lucas cell as radiation detector for radon concentration in air was also developed its detection threshold is approx. 10 Bq/m 3 . Replaceable Lucas cell of the radiometer allows for measurement of high as well as low radon concentration in short time interval. (author)

  16. THE IMPACT OF HEAVY METAL CONCENTRATION ON

    African Journals Online (AJOL)

    Temitope

    Index of geo-accumulation (Igeo), revealed no contamination of the trace metals. ... (Hg), arsenic (As) and cadmium (Cd). ... standards, and to suggest the best remedial methods ..... metal concentrations in urban soil of Ibadan metropolis,.

  17. Process for treatment of pyrochlore concentrates

    International Nuclear Information System (INIS)

    Charlot, G.

    1976-01-01

    A continuous process is described for extraction of niobium, rare earths and thorium from niobium ore concentrates which includes digesting the ore with a hot solution containing 13 to 16 moles of sulphuric acid per liter, diluting the solution to a concentration of 10 to 13 moles of sulphuric acid per liter, separating the insolubles from the solution which includes alkaline earth sulphates and the sulphates of thorium and rare earths that are present, reducing titanium in solution to the trivalent state and diluting the solution to a concentration of 5 to 7 moles of sulphuric acid per liter, separating the precipitated niobium oxide and sulphates of thorium and rare earths, and then concentrating the resulting solution to the level desired for recycle to the digestion stage. 10 Claims, No Drawings

  18. Seasonal Composite Chlorophyll Concentrations - Gulf of Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This personal geodatabase contains raster images of chlorophyll concentrations in the Gulf of Maine. These raster images are seasonal composites, and were calculated...

  19. Concentration of stable elements in food products

    International Nuclear Information System (INIS)

    Montford, M.A.; Shank, K.E.; Hendricks, C.; Oakes, T.W.

    1980-01-01

    Food samples were taken from commercial markets and analyzed for stable element content. The concentrations of most stable elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, La, Mg, Mn, Mo, Na, Rb, Sb, Sc, Se, Sr, Ta, Th, Ti, V, Zn, Zr) were determined using multiple-element neutron activation analysis, while the concentrations of other elements (Cd, Hg, Ni, Pb) were determined using atomic absorption. The relevance of the concentrations found are noted in relation to other literature values. An earlier study was extended to include the determination of the concentration of stable elements in home-grown products in the vicinity of the Oak Ridge National Laboratory. Comparisons between the commercial and local food-stuff values are discussed

  20. Nonimaging concentrators for photovoltaic arrays in space

    Science.gov (United States)

    Winston, R.; Greenman, P.; Rockey, D.

    1981-01-01

    Two stage concentrators are studied in order to design an optimum concentrator for photovoltaic arrays in space. The study is directed at designs with two-dimensional geometries because they are better suited to moderate concentrations of about 10 X to 50 X, and because the instantaneous flux distribution is more uniform. It is found that with an f/0.5 primary, where f is the focal length of the primary, the flux distribution is very smooth regardless of the angle of incidence of the radiation. As the focal ratio is increased, peaks in the distribution begin to appear. The nonuniformities can be reduced by introducing small, closely spaced distortions into the reflecting surfaces, and practical arrays can achieve a concentration of 10 when the acceptance half angle is 4.25 deg or 50 when the acceptance half angle is + or - 1 deg.

  1. [Nitrate concentrations in tap water in Spain].

    Science.gov (United States)

    Vitoria, Isidro; Maraver, Francisco; Sánchez-Valverde, Félix; Armijo, Francisco

    2015-01-01

    To determine nitrate concentrations in drinking water in a sample of Spanish cities. We used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. The median nitrate concentration was 3.47 mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15 mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. Nitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15 mg/L. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  2. Familial Resemblance for Serum Metabolite Concentrations

    NARCIS (Netherlands)

    Draisma, H.H.M.; Beekman, M.; Pool, R.; van Ommen, G.J.B; Vaarhorst, A.A.M.; de Craen, A.J.; Willemsen, G.; Slagboom, P.E.; Boomsma, D.I.

    2013-01-01

    Metabolomics is the comprehensive study of metabolites, which are the substrates, intermediate, and end products of cellular metabolism. The heritability of the concentrations of circulating metabolites bears relevance for evaluating their suitability as biomarkers for disease. We report aspects of

  3. Monitoring of radon concentration in dwellings

    International Nuclear Information System (INIS)

    Kurosawa, Ryuhei

    1991-01-01

    Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

  4. Odor concentration invariance by chemical ratio coding

    Directory of Open Access Journals (Sweden)

    Naoshige Uchida

    2008-08-01

    Full Text Available Many animal species rely on chemical signals to extract ecologically important information from the environment. Yet in natural conditions chemical signals will frequently undergo concentration changes that produce differences in both level and pattern of activation of olfactory receptor neurons. Thus, a central problem in olfactory processing is how the system is able to recognize the same stimulus across different concentrations. To signal species identity for mate recognition, some insects use the ratio of two components in a binary chemical mixture to produce a code that is invariant to dilution. Here, using psychophysical methods, we show that rats also classify binary odor mixtures according to the molar ratios of their components, spontaneously generalizing over at least a tenfold concentration range. These results indicate that extracting chemical ratio information is not restricted to pheromone signaling and suggest a general solution for concentration-invariant odor recognition by the mammalian olfactory system.

  5. Stress concentration effects in high pressure components

    International Nuclear Information System (INIS)

    Aller, J.E.

    1990-01-01

    This paper examines the stress concentration effects of sideholes in thick walled, high pressure cylinders. It has been shown that the theoretical stress concentration factor at the intersection of a small crossbore in a closed end, thick walled cylinder varies between 3.0 and 4.0. Tests have shown that this effect can be greatly reduced in practice by carefully radiusing the bore intersection and autofrettaging the cylinder. It has also been shown that the minimum stress concentration factor occurs when the main bore and sidehole or crossbore have the same diameter, and the radius of the intersection is approximately equal to the sidehole radius. When the bore and sidehole intersection angle decreases from 90 degrees, the stress concentration factor increases significantly. Knowledge of these fundamental relationships can be used in maintaining, as well ad designing, high pressure equipment

  6. Concentration variation of radon in the room

    International Nuclear Information System (INIS)

    Komaruzaman Mohd Noor; Haziman Hassan; Rosli Mahat; Yusof Md Amin

    1995-01-01

    The study was carried out to determine the variation of radon concentration in the room. Radon detector used was solid nuclear tracks detector (SSNTD) LR-115. From this result, suitable points to make radon measurement was determined

  7. Monthly Composite Chlorophyll Concentrations - Gulf of Maine

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This personal geodatabase contains raster images of chlorophyll concentrations in the Gulf of Maine. These raster images are monthly composites, and were calculated...

  8. Maximum phytoplankton concentrations in the sea

    DEFF Research Database (Denmark)

    Jackson, G.A.; Kiørboe, Thomas

    2008-01-01

    A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

  9. Building integrated concentrating photovoltaics: A review

    International Nuclear Information System (INIS)

    Chemisana, Daniel

    2011-01-01

    For building integration, Concentrating Photovoltaic (CPV) systems can offer a host of advantages over conventional flat panel devices, the most notable being: a higher electrical conversion efficiency in the PV cells, better use of space, ease of recycling of constituent materials, and reduced use of toxic products involved in the PV cells' production process. However, the viability of Building-Integrated Concentrating PV (BICPV) systems is dependent on their ability to offer a comparative economic advantage over flat panel photovoltaic technologies whose market prices are decreasing from day to day and which offer other advantages such as ease of replacement of structural elements. A comparative analysis is presented of the main existing CPV systems' suitability for use in buildings, in which the different challenges specific to integration of each system are discussed. The systems are categorized by type of concentration technology and concentration factor. (author)

  10. Concentration changes due to cathodic protection

    NARCIS (Netherlands)

    Gellings, P.J.

    1978-01-01

    By solving the appropriate diffusion equations the concentration changes are calculated in the environment of underground structures protected cathodically. It is shown that these changes are negligible under all practical circumstances.

  11. Bioaerosol concentrations - Figure 3 and Figure 4

    Data.gov (United States)

    U.S. Environmental Protection Agency — Bioaerosol concentrations. This dataset is associated with the following publication: Chattopadhyay, S., S. Perkins, M. Shaw, and T. Nichols. Evaluation of Exposure...

  12. 7746 CONCENTRATIONS OF FORMALDEHYDE IN RAIN WATERS ...

    African Journals Online (AJOL)

    Win7Ent

    2013-06-03

    Jun 3, 2013 ... The chromotropic acid method described by the. National Institute for ... concentration range of the formaldehyde in the rain waters varied from month to month throughout the six ... vicinity of vegetation [3]. Formaldehyde is the ...

  13. Concentration quenching in Nd-doped glasses

    International Nuclear Information System (INIS)

    Stokowski, S.E.; Cook, L.; Mueller, H.; Weber, M.J.

    1984-01-01

    Fluorescence from trivalent Nd in solids is unfortunately quenched by interactions between Nd ions. Thus, laser materials with high Nd concentrations have reduced efficiencies because of this self-quenching, also known as concentration quenching. Nd self-quenching in different crystals and glasses varies considerably. We are therefore investigating this effect in a large number of materials in an effort to: (1) find those materials with long Nd fluorescent lifetimes at high Nd concentrations; and (2) elucidate the basic mechanisms of quenching and how the material structure controls its magnitude. We have concentrated on Nd-doped glasses because they provide a rich variety of structures, albeit complicated by Nd site inhomogeneities, and are easily and quickly made

  14. Relations between fatty acid synthesis, pyruvate concentration and cell concentration of suspensions of isolated rat hepatocytes

    NARCIS (Netherlands)

    Beynen, A.C.; Geelen, M.J.H.

    1984-01-01

    1. 1. The cell concentration of suspensions of isolated rat hepatocytes affects both the rate of pyruvate accumulation in the incubation medium and the rate of fatty acid synthesis. 2. 2. At low cell concentrations pyruvate accumulation is directly related to the cell concentration but levels off

  15. Chromium concentrations in ruminant feed ingredients.

    Science.gov (United States)

    Spears, J W; Lloyd, K E; Krafka, K

    2017-05-01

    Chromium (Cr), in the form of Cr propionate, has been permitted for supplementation to cattle diets in the United States at levels up to 0.50 mg of Cr/kg of DM since 2009. Little is known regarding Cr concentrations naturally present in practical feed ingredients. The present study was conducted to determine Cr concentrations in feed ingredients commonly fed to ruminants. Feed ingredients were collected from dairy farms, feed mills, grain bins, and university research farms. Mean Cr concentrations in whole cereal grains ranged from 0.025 mg/kg of DM for oats to 0.041 mg/kg of DM for wheat. Grinding whole samples of corn, soybeans, and wheat through a stainless steel Wiley mill screen greatly increased analyzed Cr concentrations. Harvested forages had greater Cr concentrations than concentrates, and alfalfa hay or haylage had greater Cr concentrations than grass hay or corn silage. Chromium in alfalfa hay or haylage (n = 13) averaged 0.522 mg/kg of DM, with a range of 0.199 to 0.889 mg/kg of DM. Corn silage (n = 21) averaged 0.220 mg of Cr/kg of DM with a range of 0.105 to 0.441 mg of Cr/kg of DM. By-product feeds ranged from 0.040 mg of Cr/kg of DM for cottonseed hulls to 1.222 mg of Cr/kg of DM for beet pulp. Of the feed ingredients analyzed, feed grade phosphate sources had the greatest Cr concentration (135.0 mg/kg). Most ruminant feedstuffs and feed ingredients had less than 0.50 mg of Cr/kg of DM. Much of the analyzed total Cr in feed ingredients appears to be due to Cr contamination from soil or metal contact during harvesting, processing, or both. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. A method of uranium isotopes concentration analysis

    International Nuclear Information System (INIS)

    Lin Yuangen; Jiang Meng; Wu Changli; Duan Zhanyuan; Guo Chunying

    2010-01-01

    A basic method of uranium isotopes concentration is described in this paper. The iteration method is used to calculate the relative efficiency curve, by analyzing the characteristic γ energy spectrum of 235 U, 232 U and the daughter nuclide of 238 U, then the relative activity can be calculated, at last the uranium isotopes concentration can be worked out, and the result is validated by the experimentation. (authors)

  17. The hydrogen and deuterium concentrations in chondrites

    International Nuclear Information System (INIS)

    Robert, F.; Merlivat, L.

    1978-01-01

    Water and isotopic concentration of H 2 O + are reported. It shows a correlation between the water, the deuterium concentrations and the petrologic types of chondrites. The Chainpur meteorite has been divided into several mineralogical fractions and the results are reported. The results of Orgueil are also reported. The correlation shows that as the sulfate content increases, the water and deuterium contents decrease. The terrestrial contamination is discussed and possible deuterium variation models are presented

  18. Concentration of actinides in the food chain

    International Nuclear Information System (INIS)

    Bulman, R.A.

    1976-06-01

    Considerable concern is now being expressed over the discharge of actinides into the environment. This report presents a brief review of the chemistry of the actinides and examines the evidence for interaction of the actinides with some naturally-occurring chelating agents and other factors which might stimulate actinide concentration in the food chain of man. This report also reviews the evidence for concentration of actinides in plants and for uptake through the gastrointestinal tract. (author)

  19. Concentrated Photo Voltaics (CPV: a case study

    Directory of Open Access Journals (Sweden)

    Centro S.

    2015-01-01

    Full Text Available Concentrated PhotoVoltaic (CPV, among green energy solutions, nowadays has the ambition to reach grid-parity without subside. CPV substitutes large areas of expensive semiconductor solar cells, with concentrating optics made of cheap materials. Moreover the cells that are suitable for CPV exhibits an unprecedented efficiency and their technology is progressing every year. A case study project, TwinFocus®, will be presented in detail.

  20. Pressure drop in T's in concentric ducts

    International Nuclear Information System (INIS)

    Shock, R.A.W.

    1983-02-01

    A set of experiments has been carried out to measure the pressure drop characteristics of single-phase flow in dividing and joining right-angled T's in a concentric ducting system. These have been compared with measured pressure drops in a simple round tube system. In most tests with the concentric system the number of velocity heads lost is either similar to, or more than, the value for the round tubes. (author)

  1. Platelet Concentrates: Past, Present and Future

    OpenAIRE

    Prakash, Shobha; Thakur, Aditi

    2011-01-01

    Platelets play a crucial role in hemostasis and wound healing, platelet growth factors are well known source of healing cytokines. Numerous techniques of autologous platelet concentrates have been developed and applied in oral and maxillofacial surgery. This review describes the evolution of the first and second generation of platelet concentrates (platelet rich plasma and platelet rich fibrin respectively) from their fore runner-fibrin sealants.

  2. Radon concentration in a house of Calvados

    International Nuclear Information System (INIS)

    Leleyter, L.; Riffault, B.; Mazenc, B.

    2010-01-01

    Recent studies indicate a link between the risk of lung cancer and residential radon exposure. However, in France, awareness of this problem was made relatively late. Accordingly this study examines the radon concentration in a private home in Calvados (Normandy region). Findings show that the presence of a fireplace in a house can accelerate radon convective transfer, and that simple adjustments to interior and exterior accommodation can significantly reduce radon concentrations in the home. (authors)

  3. Quantification of Fluorine Content in AFFF Concentrates

    Science.gov (United States)

    2017-09-29

    for MilSpec compliance. Fluorocarbon surfactants are the most active components in these concentrates, and analysis of the fluorine content in the... physical requirements for AFFF concentrates includes a total fluorine content determination and a requirement for subsequent evaluations of this AFFF...the standard for fluorine content as well as the reference for chemical shift. For preparation of an NMR solution, it is important that the TFE

  4. Wave Front Sensor for Solar Concentrator Control

    Science.gov (United States)

    2009-10-01

    terrestrial-based and space-based. Both types of concentrator can be either imaging or nonimaging and they can be rigid or inflatable. Other...and T is the temperature of the absorber and propellant. In (5), Iin is input intensity with effects of the optical path through the concentrator acting...Hartmann in 1900 and was used for checking optical telescopes for aberrations. It was an array of holes in a plate placed in front of the mirror of

  5. Potassium concentration in bone of Beijing residents

    International Nuclear Information System (INIS)

    Lin Lianqing

    1994-01-01

    The author presents the measuring results of K concentration in bone ash samples of 65 residents in Beijing area by atomic absorption spectrum. The results indicate that the K concentrations in bone ash is logarithmic normal distribution, ranging level is 0.75-8.44 g/kg ash, the average and standard deviation is respectively 2.40 and 1.52 g/kg ash. The highest concentration (4.88 g/kg ash) appears in infantile stage (< 1y), the lowest concentration (1.59 g/kg ash) appears in young stage (2-5 y). The lower concentration (1.88 g/kg ash) appears in adolescence (11-20 y). The K concentration in wet bone as a percentage of weight is 0.067%. The specific activities of K-40 in bone is about 22 mBq/g wet bone. The total radioactivity of K-40 in whole bone is 220 Bq. The annual absorbed dose is received in adult bone from K-40 is estimated to be 95 μGy

  6. Uranium concentration monitor manual, secondary intermediate evaporator

    International Nuclear Information System (INIS)

    Russo, P.A.; Sprinkle, J.K. Jr.; Slice, R.W.; Strittmatter, R.B.

    1985-08-01

    This manual describes the design, operation, and measurement control procedures for the automated uranium concentration monitor on the secondary intermediate evaporator at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration in the return loop of time recirculating evaporator for purposes of process monitoring and control. A detector installed near the bottom of the return loop is used to acquire spectra of gamma rays from the evaporator solutions during operation. Pulse height analysis of each spectrum gives the information required to deduce the concentration of uranium in the evaporator solution in near-real time. The visual readout of concentration is updated at the end of every assay cycle. The readout includes an alphanumeric display of uranium concentration and an illuminated, colored LED (in an array of colored LEDs) indicating whether the measured concentration is within (or above or below) the desired range. An alphanumeric display of evaporator solution acid molarity is also available to the operator. 9 refs., 16 figs., 4 tabs

  7. Concentration of trace elements in marine organisms

    International Nuclear Information System (INIS)

    Ishii, Takaaki; Suzuki, Hamaji; Iimura, Mitsue; Koyanagi, Taku

    1976-01-01

    Information on the quality and quantity of stable trace elements in marine environments is frequently required to analyze the radioecological behavior of radionuclides released from nuclear facilities into the sea. In the present work, special attention was concentrated in determination of stable Mn, Fe, Co, Zn, Rb and Cs in marine organisms to estimate the concentration factors for these elements and corresponding radionuclides. Marine organisms (fishes, marine invertebrates and seaweeds) were collected at the seashore of Ibaragi prefecture and provided for chemical analysis after dry-ashing and wet-ashing. Atomic absorption spectrophotometry and neutron activation analysis were applied to determine the concentration of elements. The concentration of stable elements in fish muscle was independent on species of the fishes though slightly higher trends were observed in ''Usumebaru'', Sebastes nivosus for Cs, ''Ishimochi'', Nibea mitsukurii for Zn and Fe compared with other species. The concentration of Co, Zn and Fe in muscle of marine invertebrates was one order of magnitude higher than fish muscles especially in shellfishes for Co. Seaweeds showed peculiar species specificity for the concentration of stable trace elements and remarkable differences was observed between the species even among the same genus. (auth.)

  8. Isoflurane minimum alveolar concentration reduction by fentanyl.

    Science.gov (United States)

    McEwan, A I; Smith, C; Dyar, O; Goodman, D; Smith, L R; Glass, P S

    1993-05-01

    Isoflurane is commonly combined with fentanyl during anesthesia. Because of hysteresis between plasma and effect site, bolus administration of fentanyl does not accurately describe the interaction between these drugs. The purpose of this study was to determine the MAC reduction of isoflurane by fentanyl when both drugs had reached steady biophase concentrations. Seventy-seven patients were randomly allocated to receive either no fentanyl or fentanyl at several predetermined plasma concentrations. Fentanyl was administered using a computer-assisted continuous infusion device. Patients were also randomly allocated to receive a predetermined steady state end-tidal concentration of isoflurane. Blood samples for fentanyl concentration were taken at 10 min after initiation of the infusion and before and immediately after skin incision. A minimum of 20 min was allowed between the start of the fentanyl infusion and skin incision. The reduction in the MAC of isoflurane by the measured fentanyl concentration was calculated using a maximum likelihood solution to a logistic regression model. There was an initial steep reduction in the MAC of isoflurane by fentanyl, with 3 ng/ml resulting in a 63% MAC reduction. A ceiling effect was observed with 10 ng/ml providing only a further 19% reduction in MAC. A 50% decrease in MAC was produced by a fentanyl concentration of 1.67 ng/ml. Defining the MAC reduction of isoflurane by all the opioids allows their more rational administration with inhalational anesthetics and provides a comparison of their relative anesthetic potencies.

  9. Preovulatory progesterone concentration associates significantly to follicle number and LH concentration but not to pregnancy rate

    DEFF Research Database (Denmark)

    Yding Andersen, Claus; Bungum, Leif; Nyboe Andersen, Anders

    2011-01-01

    Using data from a large prospective randomized controlled trial that evaluated the effect of recombinant LH (rLH)co-administration for ovarian stimulation, the present study assessed whether progesterone concentration on the day of human chorionic gonadotrophin (HCG) administration was associated...... with or without rLH administration from day 6 of stimulation. There was no significant association between the late-follicular-phase progesterone concentration and the clinical pregnancy rate. However, progesterone concentration was strongly associated with the number of follicles and retrieved oocytes. Late......-follicular-phase LH concentration also showed a significant positive association with progesterone concentration (P = 0.018). Administration of rLH during ovarian stimulation did not affect progesterone concentration. The present study does not support an association between progesterone concentration on the day...

  10. False positive acetaminophen concentrations in icteric serum

    Directory of Open Access Journals (Sweden)

    L. de Jong

    2016-04-01

    Full Text Available Introduction: Serum concentrations of acetaminophen are measured to predict the risk of hepatotoxicity in cases of acetaminophen overdose and to identify acetaminophen use in patients with acute liver injury without a known cause. The acetaminophen concentration determines if treatment with N-acetyl cysteine, the antidote for acetaminophen poisoning, is warranted. Description: A 49-year-old woman was admitted to our hospital with a hepatic encephalopathy and a total serum bilirubin concentration of 442 µmol/l. The acetaminophen concentration of 11.5 mg/l was measured with an enzymatic-colorimetric assay, thus treatment with N-acetyl cysteine was started. Interestingly, the acetaminophen concentration remained unchanged (11.5–12.3 mg/l during a period of 4 consecutive days. In contrast, the acetaminophen concentration measured by HPLC, a chromatographic technique, remained undetectable Discussion: In the presented case, elevated bilirubin was the most likely candidate to interfere with acetaminophen assay causing false positive results. Bilirubin has intense absorbance in the ultraviolet and visible regions of the electromagnetic spectrum and for that reason it causes interference in an enzymatic-colorimetric assay. Conclusion: False positive acetaminophen laboratory test results may be found in icteric serum, when enzymatic-colorimetric assays are used for determination of an acetaminophen concentration. Questionable acetaminophen results in icteric serum should be confirmed by a non-enzymatic method, by means of ultrafiltration of the serum, or by dilution studies. Keywords: Acetaminophen, Enzymatic-colorimetric assays, HPLC, Bilirubin, Interference, Paracetamol, Liver failure, Jaundice

  11. Urea concentration in sheep’s milk

    Directory of Open Access Journals (Sweden)

    Jasmina Havranek

    2009-03-01

    Full Text Available Determining urea concentration in milk is a useful indicator for controlling supply of proteins to organisms, as well as the relationship of energy and protein in the food, thus it is finding more and more ways of practical use. The concentration of urea in milk, along with the feeding process, is influenced by a number of other factors such as: breed, stage and sequence of lactation, body mass, daily production and chemical structure of milk, number of somatic cells, season, milking.The goal of the research was to establish the influence of the breed (Island of Krk, East Frisian, lactation stage (beginning, middle and the end and the herd (3 to the concentration of urea in milk during lactation.For each breed there has been established daily quantity of milk, protein share and the concentration of urea in milk.Statistical analysis of data was conducted by using General Linear Models procedure, SAS program system (1999.The breed of sheep considerably (P<0.001 influenced daily quantity of milk, protein share and the concentration of urea in the milk.East Frisian sheep produced on average almost double the daily quantities of milk (1070 mL compared to the Krk sheep (588 mL.Protein share and the urea concentration in Krk sheep milk were higher (5.99 % and 35.97 mg/100 mL then in the milk of East Frisian sheep (5.12 % and 33.31 mg/100 mL.For both breeds the significant influence of lactation stage to the daily milk quantity has been established (0.001, that is also for the urea concentration in the milk of Krk sheep (0.001, as well as protein share in the milk of East Frisian sheep (0.001.Herd influence significantly affected daily milk quantities (0.001 and concentration of urea in the milk (0.05.The defining of the urea concentration in sheep milk should be occasionally carried out in the Republic of Croatia to establish the standard physiological values typical for the particular sheep breed.

  12. Rapid determination of radon daughter concentrations

    International Nuclear Information System (INIS)

    Bigu, J.

    1990-08-01

    A technical evaluation of four radon 222 progeny measuring instruments has been conducted. The evaluation has been carried out under laboratory controlled conditions and at several locations in an underground uranium mine. The laboratory evaluation consisted of a thorough study of the behaviour and performance of the instruments under a wide variety of environmental conditions such as radon 222 gas concentration, radon 222 progeny concentration, temperature, relative humidity, aerosol concentration, and gamma-field exposure. The four instruments tested were: the Pylon WL-1000C, the MDA IWLM-811, the MIMIL IIM, and the EDA WLM-30. The readings of the instruments were compared with a widely accepted radon 222 progeny concentration measuring method, namely, the Thomas-Tsivoglou method. Two variables affected two instruments significantly, namely, under high aerosol concentration conditions, one of the instruments (EDA WLM-30) ceased to operate because of filter loading. The other variable was gamma-field exposure which affected another instrument (MDA-811) adversely. The instruments were rated according to several criteria. The overall best performer was the MIMIL IIM, although other instruments also fared quite well under a variety of experimental conditions

  13. Plasma Glutamine Concentrations in Liver Failure.

    Directory of Open Access Journals (Sweden)

    Gunnel Helling

    Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

  14. A flexible cell concentrator using inertial focusing.

    Science.gov (United States)

    Tu, Chunglong; Zhou, Jian; Liang, Yitao; Huang, Bobo; Fang, Yifeng; Liang, Xiao; Ye, Xuesong

    2017-09-11

    Cell concentration adjustment is intensively implemented routinely both in research and clinical laboratories. Centrifuge is the most prevalent technique for tuning biosample concentration. But it suffers from a number of drawbacks, such as requirement of experienced operator, high cost, low resolution, variable reproducibility and induced damage to sample. Herein we report on a cost-efficient alternative using inertial microfluidics. While the majority of existing literatures concentrate on inertial focusing itself, we identify the substantial role of the outlet system played in the device performance that has long been underestimated. The resistances of the outlets virtually involve in defining the cutoff size of a given inertial filtration channel. Following the comprehensive exploration of the influence of outlet system, we designed an inertial device with selectable outlets. Using both commercial microparticles and cultured Hep G2 cells, we have successfully demonstrated the automated concentration modification and observed several key advantages of our device as compared with conventional centrifuge, such as significantly reduced cell loss (only 4.2% vs. ~40% of centrifuge), better preservation of cell viability and less processing time as well as the increased reproducibility due to absence of manual operation. Furthermore, our device shows high effectiveness for concentrated sample (e.g., 1.8 × 10 6 cells/ml) as well. We envision its promising applications in the circumstance where repetitive sample preparation is intensely employed.

  15. Hybrid Perovskites: Prospects for Concentrator Solar Cells.

    Science.gov (United States)

    Lin, Qianqian; Wang, Zhiping; Snaith, Henry J; Johnston, Michael B; Herz, Laura M

    2018-04-01

    Perovskite solar cells have shown a meteoric rise of power conversion efficiency and a steady pace of improvements in their stability of operation. Such rapid progress has triggered research into approaches that can boost efficiencies beyond the Shockley-Queisser limit stipulated for a single-junction cell under normal solar illumination conditions. The tandem solar cell architecture is one concept here that has recently been successfully implemented. However, the approach of solar concentration has not been sufficiently explored so far for perovskite photovoltaics, despite its frequent use in the area of inorganic semiconductor solar cells. Here, the prospects of hybrid perovskites are assessed for use in concentrator solar cells. Solar cell performance parameters are theoretically predicted as a function of solar concentration levels, based on representative assumptions of charge-carrier recombination and extraction rates in the device. It is demonstrated that perovskite solar cells can fundamentally exhibit appreciably higher energy-conversion efficiencies under solar concentration, where they are able to exceed the Shockley-Queisser limit and exhibit strongly elevated open-circuit voltages. It is therefore concluded that sufficient material and device stability under increased illumination levels will be the only significant challenge to perovskite concentrator solar cell applications.

  16. Nonimaging optics in luminescent solar concentration.

    Science.gov (United States)

    Markman, B D; Ranade, R R; Giebink, N C

    2012-09-10

    Light trapped within luminescent solar concentrators (LSCs) is naturally limited in angular extent by the total internal reflection critical angle, θcrit, and hence the principles of nonimaging optics can be leveraged to increase LSC concentration ratio by appropriately reshaping the edges. Here, we use rigorous ray-tracing simulations to explore the potential of this concept for realistic LSCs with compound parabolic concentrator (CPC)-tapered edges and show that, when applied to a single edge, the concentration ratio is increased by 23% while maintaining >90% of the original LSC optical efficiency. Importantly, we find that CPC-tapering all of the edges enables a significantly greater intensity enhancement up to 35% at >90% of the original optical efficiency, effectively enabling two-dimensional concentration through a cooperative, ray-recycling effect in which rays rejected by one CPC are accepted by another. These results open up a significant opportunity to improve LSC performance at virtually no added manufacturing cost by incorporating nonimaging optics into their design.

  17. Atmospheric relative concentrations in building wakes

    International Nuclear Information System (INIS)

    Ramsdell, J.V. Jr.; Simonen, C.A.

    1997-05-01

    This report documents the ARCON96 computer code developed for the U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation for potential use in control room habitability assessments. It includes a user's guide to the code, a description of the technical basis for the code, and a programmer's guide to the code. The ARCON96 code uses hourly meteorological data and recently developed methods for estimating dispersion in the vicinity of buildings to calculate relative concentrations at control room air intakes that would be exceeded no more than five percent of the time. The concentrations are calculated for averaging periods ranging from one hour to 30 days in duration. ARCON96 is a revised version of ARCON95, which was developed for the NRC Office of Nuclear Regulatory Research. Changes in the code permit users to simulate releases from area sources as well as point sources. The method of averaging concentrations for periods longer than 2 hours has also been changed. The change in averaging procedures increases relative concentrations for these averaging periods. In general, the increase in concentrations is less than a factor of two. The increase is greatest for relatively short averaging periods, for example 0 to 8 hours and diminishes as the duration of the averaging period increases

  18. Thin-source concentration dependent diffusion

    International Nuclear Information System (INIS)

    Eng, G.

    1978-01-01

    The diffusion of (Ca ++ ) in NaCl has been measured for various diffusion times and for the temperature range (575 0 to 775 0 C), using a thin-source of 45 Ca tracer, rectangular geometry, and serial sectioning. The pre-diffusion surface concentration was approximately 3 x 10 16 (Ca)-atoms/cm 2 , which, for an average penetration depth of 100 to 300 μm, produces a maximum (post-diffusion) impurity concentration comparable to or greater than the intrinsic cation vacancy concentration. The high-temperature function closely matches the D 0 (T) function obtained from low impurity concentration experiments. The lower-temperature function, combined with the sudden failure of the D(C) = D 0 (1 + [C] + 0.5[C] 2 ) function at these lower temperatures, indicates the onset of a second diffusion process, one which would operate only at extremely high impurity concentrations. This low-temperature behavior is shown to be consistent with a breakdown of the conditions assumed for vacancy equilibrium

  19. Hip implants - Paper VI - Ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Sargeant, A. [Department of Biological Sciences, Ohio Northern University, Ada, OH 45810 (United States); Goswami, T. [Department of Mechanical Engineering, Ohio Northern University, Ada, OH 45810 (United States)]. E-mail: t-goswami@onu.edu

    2007-07-01

    Total hip-joint arthroplasty is performed in increasing numbers where it translates to about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic or poly-ethylene liner as seen in the case of hip, knee and spine. The metal implants release ions in vivo. Therefore, there is a need to study metallic implants and ions released as a result. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. There is a need to map ion concentrations establishing boundaries between normal and toxic levels; which however, does not exist. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this paper. The concentrations of ions released from different alloys, including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium, are presented in this paper. This paper reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses, and laboratory data on the physiological effects of the metals.

  20. Uranium concentration monitor manual: 2300 system

    International Nuclear Information System (INIS)

    Russo, P.A.; Sprinkle, J.K. Jr.; Stephens, M.M.

    1985-04-01

    This manual describes the design, operation, and procedures for measurement control for the automated uranium concentration monitor on the 2300 solvent extraction system at the Oak Ridge Y-12 Plant. The nonintrusive monitor provides a near-real time readout of uranium concentration at two locations simultaneously in the solvent extraction system for process monitoring and control. Detectors installed at the top of the extraction column and at the bottom of the backwash column acquire spectra of gamma rays from the solvent extraction solutions in the columns. Pulse-height analysis of these spectra gives the concentration of uranium in the organic product of the extraction column and in the aqueous product of the solvent extraction system. The visual readouts of concentrations for process monitoring are updated every 2 min for both detection systems. Simultaneously, the concentration results are shipped to a remote computer that has been installed by Y-12 to demonstrate automatic control of the solvent extraction system based on input of near-real time process operation information. 8 refs., 13 figs., 4 tabs

  1. Concentration and limit behaviors of stationary measures

    Science.gov (United States)

    Huang, Wen; Ji, Min; Liu, Zhenxin; Yi, Yingfei

    2018-04-01

    In this paper, we study limit behaviors of stationary measures of the Fokker-Planck equations associated with a system of ordinary differential equations perturbed by a class of multiplicative noise including additive white noise case. As the noises are vanishing, various results on the invariance and concentration of the limit measures are obtained. In particular, we show that if the noise perturbed systems admit a uniform Lyapunov function, then the stationary measures form a relatively sequentially compact set whose weak∗-limits are invariant measures of the unperturbed system concentrated on its global attractor. In the case that the global attractor contains a strong local attractor, we further show that there exists a family of admissible multiplicative noises with respect to which all limit measures are actually concentrated on the local attractor; and on the contrary, in the presence of a strong local repeller in the global attractor, there exists a family of admissible multiplicative noises with respect to which no limit measure can be concentrated on the local repeller. Moreover, we show that if there is a strongly repelling equilibrium in the global attractor, then limit measures with respect to typical families of multiplicative noises are always concentrated away from the equilibrium. As applications of these results, an example of stochastic Hopf bifurcation and an example with non-decomposable ω-limit sets are provided. Our study is closely related to the problem of noise stability of compact invariant sets and invariant measures of the unperturbed system.

  2. High concentration agglomerate dynamics at high temperatures.

    Science.gov (United States)

    Heine, M C; Pratsinis, S E

    2006-11-21

    The dynamics of agglomerate aerosols are investigated at high solids concentrations that are typical in industrial scale manufacture of fine particles (precursor mole fraction larger than 10 mol %). In particular, formation and growth of fumed silica at such concentrations by chemical reaction, coagulation, and sintering is simulated at nonisothermal conditions and compared to limited experimental data and commercial product specifications. Using recent chemical kinetics for silica formation by SiCl4 hydrolysis and neglecting aerosol polydispersity, the evolution of the diameter of primary particles (specific surface area, SSA), hard- and soft-agglomerates, along with agglomerate effective volume fraction (volume occupied by agglomerate) is investigated. Classic Smoluchowski theory is fundamentally limited for description of soft-agglomerate Brownian coagulation at high solids concentrations. In fact, these high concentrations affect little the primary particle diameter (or SSA) but dominate the soft-agglomerate diameter, structure, and volume fraction, leading to gelation consistent with experimental data. This indicates that restructuring and fragmentation should affect product particle characteristics during high-temperature synthesis of nanostructured particles at high concentrations in aerosol flow reactors.

  3. Tube collector with integrated tracking parabolic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Grass, C.; Benz, N.; Hacker, Z.; Timinger, A. [ZAE Bayern, Bavarian Centre for Applied Energy Research, Muenchen (Germany)

    2000-07-01

    Low concentrating CPC collectors usually do not track the sun and are mounted in east-west direction with a latitude dependent slope angle. They are most suitable for maximum working temperatures up to 200 250 deg. C. We present a novel evacuated tube-collector with a trough-like concentrating mirror. Single-axis tracking of the mirror is realized with a magnetic mechanism. The mirror is mounted inside the evacuated tube and hence protected from environmental influences. One axis tracking in combination with a small acceptance angle allows for higher concentration as compared to non-tracking concentrating collectors. Ray-tracing analysis shows a half acceptance angle of about 5 deg. at a geometrical concentration ratio of 3.2. The losses of evacuated tube collectors are dominated by the radiation losses of the absorber. Hence, reducing the absorber size can lead to higher efficiencies at high operating temperature levels. With the presented collector we aim for operating temperatures up to 400 deg. C. At temperatures of 300 deg. C we expect efficiencies of 65 %. This allows for application in industrial process heat generation, high efficient solar cooling and power generation. A first prototype was tested at the ZAE Bayern. The optical efficiency was measured to be 75 %. (au)

  4. Metrology of radon and thoron concentrations

    International Nuclear Information System (INIS)

    Durcik, M; Vicanova, M.

    1998-01-01

    The alpha spectrometry measurements of radon (radon-222) and thoron (radon-220) concentrations by ionisation chamber, used only in laboratory conditions are described in this paper. For the measurements of radon and thoron in dwellings and work areas was proposed diffusion double chamber detector with track detector. The described dosimeter is very useful for routine measurement and would be applied in measuring of radon and thoron concentrations in caves and dwellings. Big disadvantage of the dosimeter is small holes in cover and it could not be used in dusty areas. From previous measurements of the equilibrium equivalent thoron concentrations by semiconductor detector the measured values ranged from 0.1 to 5.6 Bq m -3 in the Slovak kindergartens were obtained

  5. Progress In Fresnel-Köhler Concentrators

    Science.gov (United States)

    Mohedano, Rubén; Cvetković, Aleksandra; Benítez, Pablo; Chaves, Julio; Miñano, Juan C.; Zamora, Pablo; Hernandez, Maikel; Vilaplana, Juan

    2011-12-01

    The Fresnel Köhler (FK) concentrator was first presented in 2008. Since then, various CPV companies have adopted this technology as base for their future commercial product. The key for this rapid penetration is a mixture of simplicity (the FK is essentially a Fresnel lens concentrator, a technology that dominates the market) and excellent performance: high concentration without giving up large manufacturing/aiming tolerances, enabling high efficiency even at the array level. All these features together have a great potential to lower energy costs. This work shows recent results and progress regarding this device, covering new design features, measurements and tests along with first performance achievements at the array level (pilot 6.5 Kwp plant). The work also discusses the potential impact of the FK enhanced performance on the Levelized Cost Of Electricity (LCOE).

  6. Environmental impact of low concentrated wastes

    International Nuclear Information System (INIS)

    Barescut, J.C.

    1998-01-01

    A means to reduce the impact of a waste landfill is to limit its content so that after a reasonably short time, its radioactivity does not significantly exceed the natural level. For this means to be effective, it must be demonstrated that the system will not, in the long run, spontaneously evolve towards local sports of higher concentration. This process would require considerable converging migrations that would offer many opportunities for mixing and thus be inconsistent with concentration. Moreover, concentration is an energy-demanding process that will be limited by the availability of energy, especially in chemical form. For these reasons, it is wise to avoid placing a landfill where energy is likely to be more readily available than on the average. It is also advisable to avoid artificial protections, if their future evolution is not fully understood, since they necessarily contain an excess of energy relative to the undisturbed natural state. (author)

  7. Method of concentrating radioactive liquid waste

    International Nuclear Information System (INIS)

    Yasumura, Keijiro

    1990-01-01

    Radioactive liquid wastes generated from nuclear power facilities are caused to flow into a vessel incorporated with first hydrophobic porous membranes. Then, the radioactive liquid wastes are passed through the first hydrophobic porous membranes under an elevated or reduced pressure to remove fine particles contained in the liquid wastes. The radioactive liquid wastes passed through the first membranes are stored in a temporary store a vessel and steams generated under heating are passed through the second hydrophobic porous membranes and then cooled and concentrated as condensates. In this case, the first and the second hydrophobic porous membranes have a property of passing steams but not water and, for example, are made of tetrafluoroethylen resin type thin membranes. Accordingly, since the fine particles can be removed by the first hydrophobic porous membranes, lowering of the concentration rate due to the deposition of solid contents to the membranes upon concentration can be prevented. (I.S.)

  8. Calcium concentration in the CAPD dialysate

    DEFF Research Database (Denmark)

    Bro, S; Brandi, L; Daugaard, H

    1998-01-01

    OBJECTIVE: To evaluate risk/benefit of various continuous ambulatory peritoneal dialysis (CAPD) dialysate calcium concentrations. DATA SOURCES: A review of the literature on the effects of various CAPD dialysate Ca concentrations on plasma Ca, plasma phosphate, plasma parathyroid hormone (PTH......), doses of calcium carbonate, doses of vitamin D analogs, and requirements of aluminum-containing phosphate binders. STUDY SELECTION: Eleven studies of nonselected CAPD patients, and 13 studies of CAPD patients with hypercalcemia were reviewed. RESULTS: In nonselected CAPD patients, treatment...... with a reduced dialysate Ca concentration (1.00, 1.25, or 1.35 mmol/L) improved the tolerance to calcium carbonate and/or vitamin D metabolites and reduced the need for Al-containing phosphate binders. When using dialysate Ca 1.25 or 1.35 mmol/L, the initial decrease of plasma Ca and increase of PTH could easily...

  9. Mechanisms of urine concentration and dilution (1961)

    International Nuclear Information System (INIS)

    Morel, F.; Guinnebault, M.

    1961-01-01

    This paper is devoted to the analysis of a problem in the field of renal physiology which has shown many new developments during the course of the last few years. The following are treated successively: a) the data obtained from measurements of free water clearance and their interpretation; b) the data provided by nephron morphology and the comparative anatomy of the kidney ; c) the data relative to the existence of an intrarenal osmotic gradient; d) the principle of concentration multiplication by a counter current technique; e) the present day theory of counter current concentration of urine, and f) the physiological check on dilution and concentration mechanisms in urine. Lastly, the advantages of the modern theory and the unknown factors which remain are discussed. (authors) [fr

  10. Theory of concentrated vortices an introduction

    CERN Document Server

    Alekseenko, S V; Okulov, V L

    2007-01-01

    Vortex motion is one of the basic states of a flowing continuum. Intere- ingly, in many cases vorticity is space-localized, generating concentrated vortices. Vortex filaments having extremely diverse dynamics are the most characteristic examples of such vortices. Notable examples, in particular, include such phenomena as self-inducted motion, various instabilities, wave generation, and vortex breakdown. These effects are typically ma- fested as a spiral (or helical) configuration of a vortex axis. Many publications in the field of hydrodynamics are focused on vortex motion and vortex effects. Only a few books are devoted entirely to v- tices, and even fewer to concentrated vortices. This work aims to highlight the key problems of vortex formation and behavior. The experimental - servations of the authors, the impressive visualizations of concentrated vortices (including helical and spiral) and pictures of vortex breakdown primarily motivated the authors to begin this work. Later, the approach based on the hel...

  11. Thermogravimetric study of rare earth concentrates

    International Nuclear Information System (INIS)

    Delyagejd, V.V.; Anisimova, V.N.; Eremenko, Z.V.; Kutsev, V.S.

    1974-01-01

    Methods of thermogravimetric, chemical and phase analysis were used in measuring the concentration of rare-earth elements of different origins. At temperatures 400-800 deg C a gradual decomposition of fluorocarbonates takes place leading to the formation of derivatives of corresponding oxides and oxyfluorides. For concentrates containing siderite the process takes place at 550-600 deg C followed by oxidation of bivalent iron into trivalent state. Reaction of rare-earth elements with sodium carbonate and the increase in the concentration of the latter results in a narrowing down of the interval of temperatures at which decomposition takes place. Under these conditions an intense reaction and a fusion take place leading to the formation of eutectic at 500-600 deg C and further synthesis of sodium fluoride and oxyfluoride derivatives of calcium and rare-earth elements

  12. Degadation of semiconducting polymers by concentrated sunlight

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Manceau, Matthieu; Petersen, Martin Helgesen

    2011-01-01

    infra-red spectra of MEH-PPV degraded at 1 sun intensity and at high solar concentration only showed minor deviations in degradation mechanisms. The acceleration factor was found to vary linearly with the solar concentration. Finally, a comparison of the degradation rates at 1 sun and 100 suns...... was carried out in a materials study employing five different conjugated polymers relevant to polymer solar cells for which acceleration factors in the range 19–55 were obtained.......A lens based sunlight concentration setup was used to accelerate the degradation of semiconducting polymers. Sunlight was collected outdoor and focused into an optical fiber bundle allowing for indoor experimental work. Photo-degradation of several polymers was studied by UV–vis absorbance...

  13. Seasonal Variation in Human Salivary Cortisol Concentration

    DEFF Research Database (Denmark)

    Persson, Roger; Garde, Anne Helene; Hansen, Åse Marie

    2008-01-01

    Measurement of cortisol concentration can contribute important information about an individual's ability to adjust to various environmental demands of both physical and psychosocial origin. However, one uncertainty that affects the possibilities of correctly interpreting and designing field studies...... is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month-to-month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women...... 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time...

  14. Transparent Solar Concentrator for Flat Panel Display

    Science.gov (United States)

    Yeh, Chia-Hung; Chang, Fuh-Yu; Young, Hong-Tsu; Hsieh, Tsung-Yen; Chang, Chia-Hsiung

    2012-06-01

    A new concept of the transparent solar concentrator for flat panel display is experimentally demonstrated without adversely affecting the visual effects. The solar concentrator is based on a solar light-guide plate with micro prisms, not only increasing the absorption area of solar energy but also enhancing the conversion efficiency. The incident light is guided by the designed solar light-guide plate according to the total internal reflection (TIR), and converted into electrical power by photovoltaic solar cells. The designed transparent solar concentrator was made and measured with high transparency, namely 94.8%. The developed solar energy system for display can store energy and supply the bias voltage to light on two light-emitting diodes (LEDs) successfully.

  15. Wafer integrated micro-scale concentrating photovoltaics

    Science.gov (United States)

    Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun

    2017-09-01

    Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

  16. Policy and Concentration of Activities : The Case of Dutch Nanotechnology

    NARCIS (Netherlands)

    Cunningham, S.; Werker, C.

    2012-01-01

    Geographical concentration of economic activities has been widely discussed. However, the insights into other kinds of concentration such as technological and organizational concentration have been scarce. Here, we analyze organizational, technological and geographical concentration of

  17. Beryllium concentration in pharyngeal tonsils in children

    Directory of Open Access Journals (Sweden)

    Ewa Nogaj

    2014-06-01

    Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

  18. Effect of hemodialysis on leflunomide plasma concentrations.

    Science.gov (United States)

    Beaman, Jasmine M; Hackett, L Peter; Luxton, Grant; Illett, Kenneth F

    2002-01-01

    To report on the influence of hemodialysis on the disposition of leflunomide in a woman with end-stage renal disease. A 65-year-old white woman with a history of diabetes, end-stage renal disease, rheumatoid arthritis, vasculitis, and leg ulcers was admitted to the hospital with a flare in the symptoms of joint pain and vasculitis. Prior to admission, she had been treated for rheumatoid arthritis with methotrexate 7.5 mg once a week. Due to adverse effects from methotrexate and continuing painful joints, leflunomide was considered as a therapeutic alternative. A loading dose of 100 mg was followed two days later by a daily dose of 10 mg. The active metabolite of leflunomide (A771726) was measured before and after hemodialysis and between hemodialysis sessions over a period of 80 days. Pre- and post-hemodialysis concentrations were compared for 17 sessions during this time. Based on the initial measured concentrations, the leflunomide dose was increased to 20 mg/d for several weeks before being reduced to 15 mg due to elevated liver enzymes. Although renal pathways are responsible in part for excretion of A771726, the concentrations achieved in this patient at doses of 10-20 mg/d were at the low end of the range reported in the literature. It was shown that pre- and post-hemodialysis concentrations of A771726 did not differ significantly. Thus, the low concentrations of A771726 were not a result of the hemodialysis. Steady-state concentrations of A771726 in plasma were not affected by hemodialysis or renal impairment. Reduction of the dose of leflunomide in patients with chronic renal failure undergoing hemodialysis does not appear to be required.

  19. OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2010-03-01

    Full Text Available Ozone in the lower part of the atmosphere (troposphere, strong photochemical oxidant, is not directly emitted to the atmosphere but formed through a series of complex reactions. Ozone concentrations depends on ozone precursors air contamination (mainly nitrogen dioxide and non-methane volatile organic compounds and meteorological conditions (temperature and solar radiation. The main sectors emitted ozone precursors are road transport, power and heat generation plants, household (heating, industry, and petrol storage and distribution. Ozone and some of its precursors are also transported long distances in the atmosphere and are therefore considered a transboundary problem. As a result, the ozone concentrations are often low in busy urban areas and higher in suburban and rural areas. Nowadays, instead of particulate matter, ozone is one of the most widespread global air pollution problems. In and around urban areas, relatively large gradients of ozone can be observed. Because of its high reactivity in elevated concentrations ozone causes serious health problems and damage to ecosystems, agricultural crops and materials. Main ill-health endpoints as a results of ozone concentrations can be characterised as an effect of pulmonary and cardiovascular system, time morbidity and mortality series, development of atherosclerosis and asthma and finally reduction in life expectancy. The associations with increased daily mortality due to ozone concentrations are confirmed by many researches and epidemiological studies. Estimation of the level selected ill-health endpoints (mortality in total and due to cardiovascular and respiratory causes as a result of the short-term ozone exposure in Poland was the main aim of the project. Final results have been done based on estimation method elaborated by WHO, ozone measurements from National Air Quality Monitoring System and statistical information such as mortality rate and populations. All analysis have been done in

  20. Advertising and Concentration in the Brewing Industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Wu, Yanqing

    2014-01-01

    The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market and the wo......The paper tracks the development in industry concentrations from 2002 to 2012, discusses some of the main drivers behind this development and points to economies of scale in advertising as a main pay-off from mergers and acquisitions. Using firm-level data both from the American market...

  1. Resonance-shifting luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel Christopher; Wiederrecht, Gary P.; Wasielewski, Michael R.

    2018-01-23

    An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

  2. A time-varying magnetic flux concentrator

    International Nuclear Information System (INIS)

    Kibret, B; Premaratne, M; Lewis, P M; Thomson, R; Fitzgerald, P B

    2016-01-01

    It is known that diverse technological applications require the use of focused magnetic fields. This has driven the quest for controlling the magnetic field. Recently, the principles in transformation optics and metamaterials have allowed the realization of practical static magnetic flux concentrators. Extending such progress, here, we propose a time-varying magnetic flux concentrator cylindrical shell that uses electric conductors and ferromagnetic materials to guide magnetic flux to its center. Its performance is discussed based on finite-element simulation results. Our proposed design has potential applications in magnetic sensors, medical devices, wireless power transfer, and near-field wireless communications. (paper)

  3. Method of concentrating oil shale by flotation

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M

    1941-01-28

    A method is described of concentrating oil shale by flotation. It is characterized by grinding the shale to a grain size which, roughly speaking, is less than 0.06 mm. and more conveniently should be less than 0.05 mm., and followed by flotation. During the process the brown foam formed is separated as concentrate, while the black-brown to all-black foam is separated as a middle product, ground fine again, and thereafter floated once more. The patent contains five additional claims.

  4. Time-series analysis for ambient concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Manteiga, W.; Prada-Sanchez, J.M.; Cao, R.; Garcia-Jurado, I.; Febrero-Bande, M.; Lucas-Dominguez, T. (Santiago de Compostela University, Santiago de Compostela (Spain). Dept. of Statistics and Operations Research)

    1993-02-01

    In this paper a dynamic system is presented which has been implemented to predict, every 5 min, the ambient concentrations of SO[sub 2] in the neighbourhood of a power station run by ENDESA, the National Electricity Company of Spain, in As Pontes. This prediction task is very important in order to prevent a high ground-level of concentration of SO[sub 2]. For forecasting a mixed model is used which has a parametric component and a nonparametric one. Confidence intervals are also constructed for future observations using bootstrap and classical techniques. 4 refs., 5 figs., 3 tabs.

  5. Preparation of counterion stabilized concentrated silver sols.

    Science.gov (United States)

    LaPlante, Sylas; Halaciuga, Ionel; Goia, Dan V

    2011-07-01

    A strategy for obtaining stable concentrated silver dispersions without dedicated stabilizing agents is presented. This approach consists of rapidly mixing aqueous solutions of silver salicylate and ascorbic acid. By using salicylate as Ag(+) counterion, it is possible to prepare stable sols with metal concentrations up to two orders of magnitude higher than with silver nitrate. The stabilizing effect of the counterion is the result of a decreased ionic strength due to salicylate protonation and its adsorption on the surface of silver. Both effects increase the range of the electrostatic repulsive forces by expanding the electrical double layer. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Plasma concentration of acetylcholine in young women

    International Nuclear Information System (INIS)

    Kawashima, K.; Oohata, H.; Fujimoto, K.; Suzuki, T.

    1987-01-01

    A sensitive and specific radioimmunoassay was applied to the determination of acetylcholine (ACh) in plasma. The concentration of ACh in plasma sampled from 32 young women was 456.1+-53.1 (mean +-S.E.M.) pg/ml. No significant correlations were observed between plasma concentrations of ACh and acetylcholinesterase (AChE) activity, or gonadal hormones. These data demonstrate that an amount of ACh measurable by radioimmunoassay is present in plasma and plasma ACh is not regulated by AChE activity and the menstrual cycle in young women. The origin and physiological as well as pathophysiological significance of ACh in plasma remain to be clarified. 13 refs. (Author)

  7. Determination of natural occurring radionuclides concentrations

    International Nuclear Information System (INIS)

    Stajic, J.; Markovic, V.; Krstic, D.; Nikezic, D.

    2011-01-01

    Tobacco smoke contains certain concentrations of naturally occurring radionuclides from radioactive chains of uranium and thorium - 214 Pb, 214 Bi, 228 Ac, 208 Tl, 226 Ra, 232 Th and 40 K. Inhaling of tobacco smoke leads to internal exposure of man. In order to estimate absorbed dose of irradiation it is necessary to determine concentrations of radionuclides present in the tobacco leaves. In this paper specific activities of naturally occurring radionuclides were measured in tobacco samples from cigarettes which are used in Serbia. [sr

  8. A portable concentrator for processing plutonium

    International Nuclear Information System (INIS)

    Chamberlain, D.B.; Conner, C.; Chen, L.

    1995-01-01

    A horizontal, agitated film concentrator designed to concentrate liquid streams to a high solid content slurry is briefly described. The Rototherm unit is being studied for use at US Department of Energy facilities to handle large quantities of aqueous plutonium solutions. Capabilities for evaporating more than 98% of the water present in a single pass have been demonstrated. Decontamination factors of 10 6 to 10 7 are expected. The unit may also be useful for recycling aqueous waste treatment reagents from the decontamination of gaseous diffusion plants

  9. Design package for concentrating solar collector panels

    Energy Technology Data Exchange (ETDEWEB)

    1978-08-01

    Information used to evaluate the design of the Northrup concentrating collector is presented. Included are the system performance specifications, the applications manual, and the detailed design drawings of the collector. The Northrup concentrating solar collector is a water/glycol/working fluid type, dipped galvanized steel housing, transparent acrylic Fresnel lens cover, copper absorber tube, fiber glass insulation and weighs 98 pounds. The gross collector area is about 29.4/sup 2/ per collector. A collector assembly includes four collector units within a tracking mount array.

  10. Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate

    International Nuclear Information System (INIS)

    Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

    2005-01-01

    Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs

  11. Experimental characterization of a concentrating photovoltaic system varying the light concentration

    International Nuclear Information System (INIS)

    Renno, C.; Petito, F.; Landi, G.; Neitzert, H.C.

    2017-01-01

    Highlights: • Experimental characterization of a concentrating photovoltaic system. • Analysis of the point-focus concentrating system performances. • Photovoltaic system parameters as function of the concentration factor. - Abstract: The concentrating photovoltaic system represents one of the most promising solar technologies because it allows a more efficient energy conversion. When a CPV system is designed, the main parameter which has to be considered is the concentration factor that affects both the system energy performances and its configuration. An experimental characterization of a CPV system previously realized at the University of Salerno, is presented in this paper considering several aspects related to the optical configuration, the concentration factor and the solar cell used. In particular, the parameters of an Indium Gallium Phosphide/Gallium Arsenide/Germanium triple-junction solar cell are investigated as function of the concentration factor determined by means of an experimental procedure that uses different optical configurations. The maximum concentration factor reached by the CPV system is 310 suns. The cell parameters dependence on the concentration is reported together with an electroluminescence analysis of the Indium Gallium Phosphide/Gallium Arsenide/Germanium cell. A monitoring of the electrical power provided by the system during its working is also presented corresponding to different direct irradiance values. A mean power of 2.95 W with an average efficiency of 32.8% is obtained referring to a mean irradiance of 930 W/m"2; lower values are obtained when the irradiance is highly fluctuating. The concentrating photovoltaic system electric energy output is estimated considering different concentration levels; the maximal obtained value is 23.5 W h on a sunny day at 310×. Finally, the temperature of the triple-junction solar cell is evaluated for different months in order to evaluate the potential annual thermal energy production

  12. Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice

    OpenAIRE

    Boudreau, Thomas F.; Peck, Gregory M.; O'Keefe, Sean F.; Stewart, Amanda C.

    2017-01-01

    Abstract Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple (Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest f...

  13. The concentration of iodine in horse serum and its relationship with thyroxin concentration by geological difference.

    Science.gov (United States)

    Mochizuki, Mariko; Hayakawa, Noriyuki; Minowa, Fumiko; Saito, Akihiro; Ishioka, Katsumi; Ueda, Fukiko; Okubo, Kimihiro; Tazaki, Hiroyuki

    2016-04-01

    In this study, iodine and thyroxin (T4) concentrations in the serum of 69 horses were investigated. Higher iodine concentrations were obtained from the horses housed in Chiba Prefecture. In contrast, T4 concentrations of horses at Shizuoka Prefecture were higher than those of horses at Chiba Prefecture. There was a significant correlation (r = 0.643, P geological differences. It was thought that equine serum is a useful sample for monitoring.

  14. Studies on influence of environmental factors on concentration on concentration of radionuclides

    International Nuclear Information System (INIS)

    Anon.

    1974-01-01

    Environmental factors which seemed to influence the concentration of radionuclides to marine organisms including illumination, water temperature, coexisting stable elements, salt concentration, suspended matters in sea water and residue were studied. The influence of illumination was examined by algae using 137 Cs, 60 Co, 85 Sr, and 106 Ru as tracers, within 24 hours of illumination. The concentration of 137 Cs and 60 Co revealed remarkable increase of uptake in accordance with increasing illumination intensity, and 24 hours illumination showed 2 times concentration of that by 4 hours'. 85 Sr and 106 Ru showed no effect of illumination, and suggested their concentration was depending on adsorption to the surface. As for water temperature, the concentration factor of 65 Zn, 137 Cs obtained from fishes and shells by 22 0 C breeding was 2 times of that by 12 0 C breeding. Concerning the influence of coexisting stable elements, fishes and shells were examined by 54 Mn, 60 Co, and 65 Zn as tracers. When the stable elements concentration in sea water became 10 times the normal, concentration factor depending on adsorption and metabolism became respective one tenth and one second of the normal value. The influence of salt concentration was examined using 85 Sr, 65 Zn, and 137 Cs, and revealed that 28 to 40 per cent changes of salt level gave slight influence on concentration factor. In order to study the influence of suspended matters and quality of residue, 3 kinds of 106 Ru complex species were added. Concentration factor of Hijiki (Hijikia fusiforme) showed no remarkable difference between breeding in filtrated and non-filtrated sea water. However, clams living in the sand should be taken care of the concentration by the residue in the sea bottom. (Kanao, N.)

  15. Effect of Crude Protein Levels in Concentrate and Concentrate Levels in Diet on Fermentation

    Directory of Open Access Journals (Sweden)

    Dinh Van Dung

    2014-06-01

    Full Text Available The effect of concentrate mixtures with crude protein (CP levels 10%, 13%, 16%, and 19% and diets with roughage to concentrate ratios 80:20, 60:40, 40:60, and 20:80 (w/w were determined on dry matter (DM and organic matter (OM digestibility, and fermentation metabolites using an in vitro fermentation technique. In vitro fermented attributes were measured after 4, 24, and 48 h of incubation respectively. The digestibility of DM and OM, and total volatile fatty acid (VFA increased whereas pH decreased with the increased amount of concentrate in the diet (p<0.001, however CP levels of concentrate did not have any influence on these attributes. Gas production reduced with increased CP levels, while it increased with increasing concentrate levels. Ammonia nitrogen (NH3-N concentration and microbial CP production increased significantly (p<0.05 by increasing CP levels and with increasing concentrate levels in diet as well, however, no significant difference was found between 16% and 19% CP levels. Therefore, 16% CP in concentrate and increasing proportion of concentrate up to 80% in diet all had improved digestibility of DM and organic matter, and higher microbial protein production, with improved fermentation characteristics.

  16. Qualification standard for photovoltaic concentrator modules

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R.; Kurtz, S.; Bottenberg, W. R.; Hammond, R.; Jochums, S. W.; McDanal, A. J.; Roubideaux, D.; Whitaker, C.; Wohlgemuth, J.

    2000-05-05

    The paper describes a proposed qualification standard for photovoltaic concentrator modules. The standard's purpose is to provide stress tests and procedures to identify any component weakness in photovoltaic concentrator modules intended for power generation applications. If no weaknesses are identified during qualification, both the manufacturer and the customer can expect a more reliable product. The qualification test program for the standard includes thermal cycles, humidity-freeze cycles, water spray, off-axis beam damage, hail impact, hot-spot endurance, as well as electrical tests for performance, ground continuity, isolation, wet insulation resistance, and bypass diodes. Because concentrator module performance can not be verified using solar simulator and reference cell procedures suitable for flat-plate modules, the standard specifies an outdoor I-V test analysis allowing a performance comparison before and after a test procedure. Two options to this complex analysis are the use of a reference concentrator module for side-by-side outdoor comparison with modules undergoing various tests and a dark I-V performance check.

  17. Determination of Rn concentration in groundwater

    International Nuclear Information System (INIS)

    Takada, Shigeru; Handa, Madoka; Okano, Yasuhiro; Saito, Masaaki; Suzuki, Takashi

    1984-01-01

    The method of prediction of earthquakes by the change of concentration of Rn in groundwater was developed by U.S.S.R. and People's Republic of China, and was not known clearly. Since 1975, the research works on this subject were commenced by University of Tokyo, Geological Survey of Agency of Industrial Science and Technology and Tokyo Metropolitan Isotopic Research Center. Along with the development of an automatic continuous measuring apparatus with high reliability, the systems for the measurement of the Rn concentration in groundwater were established. At the time of the earthquake off Izu-Oshima on January 14, 1978, clear precursor was found in an artesian flowing well in Nakaizu 0f Izu Peninsula, and the unusual phenomena which seemed be the precursor of an earthquake were recognized in other districts of Izu and Tokai. On August 8, 1983, an earthquake of magnitude 6 occurred in the boundary region of Yamanashi and Kanagawa Prefectures. Preceding the earthquake, the unusual change of the concentration of Rn was recognized at several observation wells in Tokyo, and the unusual change was observed after the earthquake also. The possibility that the unusual change of the Rn concentration in groundwater is the precursor of earthquakes is high, and this phenomenon is expected to make contribution for the prediction of earthquakes, though there remain many problems to be solved. Further works are scheduled to establish the practical method of predicting earthquakes. (Isimitsu, A.)

  18. Multistate Luminescent Solar Concentrator "Smart" Windows

    NARCIS (Netherlands)

    Sol, Jeroen A.H.P.; Timmermans, Gilles H.; Breugel, van Abraham J.; Schenning, Albertus P.H.J.; Debije, Michael G.

    2018-01-01

    A supertwist liquid crystalline luminescent solar concentrator (LSC) "smart" window is fabricated which can be switched electrically between three states: one designed for increased light absorption and electrical generation (the "dark" state), one for transparency (the "light" state), and one for

  19. Serum immunoreactive calcitonin concentration in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Dugard, J; Kew, M C; Da Fonseca, M; Levin, J [University of the Witwatersrand, Johannesburg (South Africa)

    1982-08-21

    Having found raised serum calcitonin concentrations in 94% of patients with hepatocellular carcinoma when using a dextran-coated-charcoal radio-immunoassay, we have now repeated the study, using a double-antibody radio-immunoassay, in 102 further patients with hepatocellular carcinoma and 35 matched controls. Serum immunoreactive calcitonin concentrations (iCT) in the controls ranged from 10 to 310 pg/ml (mean 154,6 pg/ml). Values in the tumour patients ranged from 10 to 1,650 pg/ml (mean 302,6 pg/ml). The mean figures were significantly higher in the tumour patients (P smaller than 0,001), 35.5% of them having values above 310 pg/ml. In 65 of the patients serum iCT concentrations were also determined by dextran-coated-charcoal radio-immunoassay. Values ranged from 10 to 10780 pg/ml (mean 2,179 pg/ml). If 1,000 pg/ml is taken as the upper limit of normal, 69% of the patients had raised iCT concentrations. There was a good correlation (r=0,67; P smaller than 0,001) between serum iCT values measured with both methods in 50 patients. If measured by the double-antibody radio-immunoassay method, the serum calcitonin value is not useful as a marker for hepatocellular carcinoma.

  20. Solar Concentrating Façade

    NARCIS (Netherlands)

    Ezzahiri, Sidi Mohamed; Nasif, Badia S.; Krieg, Jan; Bakker, Anco; Infante Ferreira, C.A.; Auer, Thomas; Knaack, Ulrich; Schneider, Jens

    2017-01-01

    The search for renewable energy sources is a wide area in which significant progress is still expected. This paper focuses on an energy system that uses Fresnel lenses to concentrate sunlight on a tubing system to heat up the working fluid. Fresnel lenses are lighter, thinner and cheaper to build