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Sample records for simpevarp area se

  1. Hydrogeochemical evaluation for Simpevarp model version 1.2. Preliminary site description of the Simpevarp area

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (ed.) [Geopoint AB, Stockholm (Sweden)

    2004-12-01

    shallow to intermediate (150-300 m) depths at Simpevarp, but at greater depths (approx. 900-1100 m) at Laxemar. At Simpevarp the groundwaters are mainly Na-Ca-Cl in type but some Na-Ca(Mg)-Cl(Br) types also occur. At Laxemar there is a transition to more Ca-Na-Cl types with depth. Main reactions involve weathering, ion exchange (Ca, Mg) and dissolution/precipitation of calcite. Redox reactions include precipitation of pyrite and some microbially-mediated reactions (SRB). At Simpevarp there is potentially some residual Littorina Sea (old marine) component, commonly in fracture zones close to or under the Baltic Sea. At both the Simpevarp and Laxemar sites there is a glacial component and also a deep saline (non-marine) component. TYPE C: This type comprises reducing saline groundwaters (6000-20 000 mg/L Cl; 25- 30 g/L TDS) present at intermediate to deep (>300 m) levels at Simpevarp, and at even greater depths (approx. 1200 m) at Laxemar. At Simpevarp the groundwaters are mainly Na-Ca-Cl with increasingly enhanced Br and SO{sub 4} with depth. At Laxemar they are mainly Ca-Na-Cl also with increasing enhancements of Br and SO{sub 4} with depth. Main reactions involve ion exchange (Ca). At both sites a glacial component and a deep saline component are present. At Simpevarp the saline component may be potentially non marine and/or non-marine/old Littorina marine in origin; at Laxemar it is more likely to be non-marine in origin. TYPE D: This type comprises reducing highly saline groundwaters (> 20 000 mg/L Cl; to a maximum of {approx}70 g/L TDS) and only has been identified at Laxemar at depths exceeding 1200 m. It is mainly Ca-Na-Cl with higher Br but lower SO{sub 4} compared to Type C groundwaters. Main reactions involve water/rock interaction for long residence non-marine brines driven by diffusion. A modelling approach was used to simulate the composition of the highly saline or brine groundwaters and, in the Simpevarp area, concluded that mixing is the main irreversible

  2. Hydrogeochemical evaluation for Simpevarp model version 1.2. Preliminary site description of the Simpevarp area

    International Nuclear Information System (INIS)

    Laaksoharju, Marcus

    2004-12-01

    to Type C groundwaters. Main reactions involve water/rock interaction for long residence non-marine brines driven by diffusion. A modelling approach was used to simulate the composition of the highly saline or brine groundwaters and, in the Simpevarp area, concluded that mixing is the main irreversible process. It controls chloride concentration that, in turn, determines the re-equilibrium path (water-rock interaction) triggered by mixing. Coupled transport modelling was used to model the groundwater age, tritium content and calcite dissolution/precipitation processes at shallow groundwater depths at both Laxemar and Simpevarp. The modelled results provide additional support to hydrogeological models by using independent hydrochemical information and added support to the general hydrogeochemical understanding of the site. In this evaluation the groundwater model has been updated, the salinity distribution, mixing processes and the major reactions altering the groundwaters have been modelled down to a depth of 1000 m, and an updated Hydrogeochemical Site Descriptive Model version 1.2 has been produced. More groundwater and isotopic data, together with microbial information, colloids and gases, provided additional site descriptive information. Finally, the introduction of coupled modelling provided additional possibilities to address independently the various processes in question

  3. Paleohydrogeological events recorded by stable isotopes, fluid inclusions and trace elements in fracture minerals in crystalline rock, Simpevarp area, SE Sweden

    International Nuclear Information System (INIS)

    Drake, Henrik; Tullborg, Eva-Lena

    2009-01-01

    Fracture minerals calcite, pyrite, gypsum, barite and quartz, formed during several events have been analysed for δ 13 C, δ 18 O, δ 34 S, 87 Sr/ 86 Sr, trace element chemistry and fluid inclusions in order to gain knowledge of the paleohydrogeological evolution of the Simpevarp area, south-eastern Sweden. This area is dominated by Proterozoic crystalline rocks and is currently being investigated by the Swedish Nuclear Fuel and Waste Management Co. (SKB) in order to find a suitable location for a deep-seated repository for spent nuclear fuel. Knowledge of the paleohydrogeological evolution is essential to understand the stability or evolution of the groundwater system over a time scale relevant to the performance assessment for a spent nuclear fuel repository. The ages of the minerals analysed range from the Proterozoic to possibly the Quaternary. The Proterozoic calcite and pyrite show inorganic and hydrothermal-magmatic stable isotope signatures and were probably formed during a long time period as indicated by the large span in temperatures (c. 200-360 deg. C) and salinities (0-24 wt.% eq. CaCl 2 ), obtained from fluid inclusion analyses. The Paleozoic minerals were formed from organically influenced brine-type fluids at temperatures of 80-145 deg. C. The isotopic results indicate that low temperature calcite and pyrite may have formed during different events ranging in time possibly from the end of the Paleozoic until the Quaternary. Formation conditions ranging from fresh to brackish and saline waters have been distinguished based on calcite crystal morphologies. The combination of δ 18 O and crystal morphologies show that the fresh-saline water interface has changed considerably over time, and water similar to the present meteoric water and brackish seawater at the site, have most probably earlier been residing in the bedrock. Organic influence and closed system in situ microbial activity causing disequilibrium are indicated by extremely low δ 13 C (down

  4. Preliminary site description. Simpevarp area - version 1.1

    International Nuclear Information System (INIS)

    Winberg, Anders

    2004-08-01

    Site characterisation in the Oskarshamn area is currently conducted at two adjoining localities, the Simpevarp and Laxemar subareas. This report presents the interim version (model version Simpevarp 1.1 of S1.1 for short) of the preliminary Site Descriptive Model for the Simpevarp subarea. The basis for this interim version is quality-assured, geoscientific and ecological field data from the Simpevarp subarea (and in part from the Laxemar area) available in the SKB SICADA and GIS data bases as of July 1, 2003 as well as version 0 of the Site Descriptive Model. The new data collected during the initial site investigation phase up till the date of data freeze S1.1 constitute the basis for the update of version 0 to version S1.1. These data include results from surface investigations in the subarea with its regional environment and from drillings and investigations in boreholes. The surface-based data sets were, in a relative sense, extensive compared with data sets from boreholes, were the information largely was limited to information from one c. 1,000 m deep cored borehole (KSH01A), two existing cored boreholes and three c. 200 m deep percussion-drilled boreholes. Discipline-specific models are developed for the selected regional and local model volumes and these models are subsequently integrated into a unified site description. The current methodologies for developing discipline-specific models and their integration are documented in methodology/ strategy reports. In the present work, the procedures and guidelines given in those reports were followed to the extent possible given the data and information available at the time of data freeze for model version S1.1. Compared with version 0 there are considerable additional features in the version S1.1, especially in the geological description and in the description of the near surface. The geological models of lithology and deformation zones are based on borehole information and surface data of much higher

  5. Preliminary site description. Simpevarp area - version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, Anders [ed.

    2004-08-01

    Site characterisation in the Oskarshamn area is currently conducted at two adjoining localities, the Simpevarp and Laxemar subareas. This report presents the interim version (model version Simpevarp 1.1 of S1.1 for short) of the preliminary Site Descriptive Model for the Simpevarp subarea. The basis for this interim version is quality-assured, geoscientific and ecological field data from the Simpevarp subarea (and in part from the Laxemar area) available in the SKB SICADA and GIS data bases as of July 1, 2003 as well as version 0 of the Site Descriptive Model. The new data collected during the initial site investigation phase up till the date of data freeze S1.1 constitute the basis for the update of version 0 to version S1.1. These data include results from surface investigations in the subarea with its regional environment and from drillings and investigations in boreholes. The surface-based data sets were, in a relative sense, extensive compared with data sets from boreholes, were the information largely was limited to information from one c. 1,000 m deep cored borehole (KSH01A), two existing cored boreholes and three c. 200 m deep percussion-drilled boreholes. Discipline-specific models are developed for the selected regional and local model volumes and these models are subsequently integrated into a unified site description. The current methodologies for developing discipline-specific models and their integration are documented in methodology/ strategy reports. In the present work, the procedures and guidelines given in those reports were followed to the extent possible given the data and information available at the time of data freeze for model version S1.1. Compared with version 0 there are considerable additional features in the version S1.1, especially in the geological description and in the description of the near surface. The geological models of lithology and deformation zones are based on borehole information and surface data of much higher

  6. Geologic facts for priority site selection in the area west of Simpevarp. Reports 1-4

    International Nuclear Information System (INIS)

    Wahlgren, Carl-Henric; Persson, Lena; Danielsson, Peter; Berglund, Johan; Triumf, Carl-Axel; Mattsson, Haakan; Thunehed, Hans

    2003-03-01

    The area west of Simpevarp at Oskarshamn is a candidate site for the Swedish repository for high-level radioactive waste. Since the available information of geologic structures in the area is not very detailed, measurements and interpretation of existing data have been performed in order to find inhomogeneities and local lineaments. Surveys were made air and by geophysical measurements in the field

  7. Description of surface systems. Preliminary site description Simpevarp sub area - Version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Lindborg, Tobias [ed.

    2005-03-01

    Swedish Nuclear Fuel and Waste Management Co is currently conducting site characterisation in the Simpevarp area. The area is divided into two subareas, the Simpevarp and the Laxemar subarea. The two subareas are surrounded by a common regional model area, the Simpevarp area. This report describes both the regional area and the subareas. This report is an interim version (model version 1.2) of the description of the surface systems at the Simpevarp area, and should be seen as a background report to the site description of the Simpevarp area, version 1.2, SKB-R--05-08. The basis for this description is quality-assured field data available in the SKB SICADA and GIS databases, together with generic data from the literature. The Surface system, here defined as everything above the bedrock, comprises a number of separate disciplines (e.g. hydrology, geology, topography, oceanography and ecology). Each discipline has developed descriptions and models for a number of properties that together represent the site description. The current methodology for developing the surface system description and the integration to ecosystem models is documented in a methodology strategy report SKB-R--03-06. The procedures and guidelines given in that report were followed in this report. Compared with version 1.1 of the surface system description SKB-R--04-25, this report presents considerable additional features, especially in the ecosystem description (Chapter 4) and in the description of the surface hydrology (Section 3.4). A first attempt has also been made to connect the flow of matter (carbon) between the different ecosystems into an overall ecosystem model at a landscape level. A summarised version of this report is also presented in SKB-R--05-08 together with geological-, hydrogeological-, transport properties-, thermal properties-, rock mechanics- and hydrogeochemical descriptions.

  8. Description of surface systems. Preliminary site description Simpevarp sub area - Version 1.2

    International Nuclear Information System (INIS)

    Lindborg, Tobias

    2005-03-01

    Swedish Nuclear Fuel and Waste Management Co is currently conducting site characterisation in the Simpevarp area. The area is divided into two subareas, the Simpevarp and the Laxemar subarea. The two subareas are surrounded by a common regional model area, the Simpevarp area. This report describes both the regional area and the subareas. This report is an interim version (model version 1.2) of the description of the surface systems at the Simpevarp area, and should be seen as a background report to the site description of the Simpevarp area, version 1.2, SKB-R--05-08. The basis for this description is quality-assured field data available in the SKB SICADA and GIS databases, together with generic data from the literature. The Surface system, here defined as everything above the bedrock, comprises a number of separate disciplines (e.g. hydrology, geology, topography, oceanography and ecology). Each discipline has developed descriptions and models for a number of properties that together represent the site description. The current methodology for developing the surface system description and the integration to ecosystem models is documented in a methodology strategy report SKB-R--03-06. The procedures and guidelines given in that report were followed in this report. Compared with version 1.1 of the surface system description SKB-R--04-25, this report presents considerable additional features, especially in the ecosystem description (Chapter 4) and in the description of the surface hydrology (Section 3.4). A first attempt has also been made to connect the flow of matter (carbon) between the different ecosystems into an overall ecosystem model at a landscape level. A summarised version of this report is also presented in SKB-R--05-08 together with geological-, hydrogeological-, transport properties-, thermal properties-, rock mechanics- and hydrogeochemical descriptions

  9. The potential for ore, industrial minerals and commercial stones in the Simpevarp area

    International Nuclear Information System (INIS)

    Lindroos, Hardy

    2004-10-01

    On behalf of SKB (the Swedish Nuclear Fuel and Waste Management Company), a survey has been made of existing information concerning the potential for ore, industrial minerals and commercial stones in and around the two candidate areas for a deep repository in Oskarshamn. A deep repository for spent nuclear fuel should not be located in a rock type or in an area where mineral extraction might be considered in the future, since this would make it difficult or impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities.The survey has made use of the geoscientific information compiled in the more regional investigations in Oskarshamn Municipality in 1998-99. The new information after the municipal study includes extensive geophysical measurements from both the air and the ground. The results of the recently completed geophysical helicopter survey of the Simpevarp area are presented in a special chapter. The judgement of an area's ore potential is in part based on the evaluation of these geophysical measurements. In order to be better able to judge the ore potential, a geochemical investigation of soil samples, including reanalysing of older samples collected by the Geological Survey of Sweden (SGU), has been carried out. The report also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. In cooperation with SGU a mineral resource map of the Simpevarp area has been prepared. The map shows two areas with a potential for commercial stones, namely the granites at Goetemar and Uthammar, situated in the northernmost respectively the southernmost part of the study area. Furthermore, the Goetemar granite has probably a small potential for ores containing tin (Sn) and/or wolfram (W). Although no mineralizations of this type have so far been found, the Goetemar granite area may be unsuitable or for

  10. The potential for ore, industrial minerals and commercial stones in the Simpevarp area

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, Hardy [MIRAB Mineral Resurser AB, Uppsla (Sweden)

    2004-10-01

    On behalf of SKB (the Swedish Nuclear Fuel and Waste Management Company), a survey has been made of existing information concerning the potential for ore, industrial minerals and commercial stones in and around the two candidate areas for a deep repository in Oskarshamn. A deep repository for spent nuclear fuel should not be located in a rock type or in an area where mineral extraction might be considered in the future, since this would make it difficult or impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities.The survey has made use of the geoscientific information compiled in the more regional investigations in Oskarshamn Municipality in 1998-99. The new information after the municipal study includes extensive geophysical measurements from both the air and the ground. The results of the recently completed geophysical helicopter survey of the Simpevarp area are presented in a special chapter. The judgement of an area's ore potential is in part based on the evaluation of these geophysical measurements. In order to be better able to judge the ore potential, a geochemical investigation of soil samples, including reanalysing of older samples collected by the Geological Survey of Sweden (SGU), has been carried out. The report also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. In cooperation with SGU a mineral resource map of the Simpevarp area has been prepared. The map shows two areas with a potential for commercial stones, namely the granites at Goetemar and Uthammar, situated in the northernmost respectively the southernmost part of the study area. Furthermore, the Goetemar granite has probably a small potential for ores containing tin (Sn) and/or wolfram (W). Although no mineralizations of this type have so far been found, the Goetemar granite area may be unsuitable or

  11. Coupled hydrogeological and reactive transport modelling of the Simpevarp area (Sweden)

    International Nuclear Information System (INIS)

    Molinero, Jorge; Raposo, Juan R.; Galindez, Juan M.; Arcos, David; Guimera, Jordi

    2008-01-01

    The Simpevarp area is one of the alternative sites being considered for the deep geological disposal of high level radioactive waste in Sweden. In this paper, a coupled regional groundwater flow and reactive solute transport model of the Simpevarp area is presented that integrates current hydrogeological and hydrochemical data of the area. The model simulates the current hydrochemical pattern of the groundwater system in the area. To that aim, a conceptual hydrochemical model was developed in order to represent the dominant chemical processes. Groundwater flow conditions were reproduced by taking into account fluid-density-dependent groundwater flow and regional hydrogeologic boundary conditions. Reactive solute transport calculations were performed on the basis of the velocity field so obtained. The model was calibrated and sensitivity analyses were carried out in order to investigate the effects of heterogeneities of hydraulic conductivity in the subsurface medium. Results provided by the reactive transport model are in good agreement with much of the measured hydrochemical data. This paper emphasizes the appropriateness of the use of reactive solute transport models when water-rock interaction reactions are involved, and demonstrates what powerful tools they are for the interpretation of hydrogeological and hydrochemical data from site geological repository characterization programs, by providing a qualitative framework for data analysis and testing of conceptual assumptions in a process-oriented approach

  12. Repository for spent nuclear fuel. Preliminary construction description - layout D Oskarshamn the Simpevarp area; Slutfoervar foer anvaent kaernbraensle. Preliminaer anlaeggningsbeskrivning - layout D. Oskarshamn, delomraade Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-02-15

    This report presents the preliminary design of a repository located in the Simpevarp area. The description has been disposed so as to deal primarily with the site dependent layouts for the above- and underground constructions. The report is disposed as follows: c1 gives the background and some basic information. Chapter 2 presents the demands and necessary conditions that take precedence when adapting the plant to the local conditions, construction, operation and closure. Chapter 3 is a general description of the area, its infrastructure and the specific sites that have been studied. Chapter 4-5 describe the design of the plant for the two chosen sites. Chapter 6 gives a review of data for the plant, and Chapter 7 'References' is the last part of the main document. The appendices A-I give brief information on the general, non-site specific, parts of the plant, e.g. buildings, life cycle, system, operation and organization.

  13. Repository for spent nuclear fuel. Preliminary construction description - layout D Oskarshamn the Simpevarp area

    International Nuclear Information System (INIS)

    2006-02-01

    This report presents the preliminary design of a repository located in the Simpevarp area. The description has been disposed so as to deal primarily with the site dependent layouts for the above- and underground constructions. The report is disposed as follows: c1 gives the background and some basic information. Chapter 2 presents the demands and necessary conditions that take precedence when adapting the plant to the local conditions, construction, operation and closure. Chapter 3 is a general description of the area, its infrastructure and the specific sites that have been studied. Chapter 4-5 describe the design of the plant for the two chosen sites. Chapter 6 gives a review of data for the plant, and Chapter 7 'References' is the last part of the main document. The appendices A-I give brief information on the general, non-site specific, parts of the plant, e.g. buildings, life cycle, system, operation and organization

  14. Geologic facts for priority site selection in the area west of Simpevarp. Reports 1-4; Geologiskt underlag foer val av prioriterad plats inom omraadet vaester om Simpevarp. Delrapport 1-4

    Energy Technology Data Exchange (ETDEWEB)

    Wahlgren, Carl-Henric; Persson, Lena [SGU, Uppsala (Sweden); Danielsson, Peter; Berglund, Johan [SwedPower AB, Stockholm (Sweden); Triumf, Carl-Axel; Mattsson, Haakan; Thunehed, Hans [GeoVista AB, Luleaa (Sweden)

    2003-03-01

    The area west of Simpevarp at Oskarshamn is a candidate site for the Swedish repository for high-level radioactive waste. Since the available information of geologic structures in the area is not very detailed, measurements and interpretation of existing data have been performed in order to find inhomogeneities and local lineaments. Surveys were made air and by geophysical measurements in the field.

  15. Ductile and brittle structural evolution of the Laxemar-Simpevarp area: an independent analysis based on local and regional constraints

    International Nuclear Information System (INIS)

    Viola, Giulio

    2008-10-01

    This report discusses the main aspects of the ductile and brittle deformational evolution of the Laxemar-Simpevarp area. Based on the interpretation of existing potential field geophysical data, it is suggested that the structural ductile grain of the region is controlled by large, c. EW trending shear zones with an overall sinistral strike-slip kinematics. The Oskarshamn Shear Zone (OSZ) and the Mederhult lineament are two examples of these shear zones and it is proposed that the ductile lineaments mapped in Laxemar-Simpevarp are genetically linked to shearing accommodated by these shear zones. The structural interpretation of the geophysical imagery of the Laxemar-Simpevarp regional model area and the available meso-scale structural information indicate that the Laxemar-Simpevarp study area can be interpreted as the analogue of a large-scale S/C' structural pattern. In detail, the Aespoe shear zone and other similarly oriented ductile shears represent C' shear bands that deform sinistrally the intervening EW lineaments (the S surfaces), which locally are significantly crenulated/folded in response to their asymptotic bending into the C' shears. This geometric and kinematic interpretation implies that, in contrast to existing reconstructions and models, EW- and not NE-trending shear zones become the main structural ductile feature of the region. Shear forces acting parallel to these main zones can successfully explain all the ductile structures described and reported from the area. The greatest compressive stress at the time of ductile shearing would trend NE-SW. The brittle deformation history of the region is complex and results from the multiple reactivation of fracture- and fault sets caused by the many orogenic episodes that affected the area during 1.5 Gyr of geological brittle evolution. Fault-slip data from outcrops and oriented drill cores were used to compute paleo-stress states. In the general absence of time markers that help constrain the relative

  16. Ductile and brittle structural evolution of the Laxemar-Simpevarp area: an independent analysis based on local and regional constraints

    Energy Technology Data Exchange (ETDEWEB)

    Viola, Giulio (Geological Survey of Norway, Trondheim (Norway))

    2008-10-15

    This report discusses the main aspects of the ductile and brittle deformational evolution of the Laxemar-Simpevarp area. Based on the interpretation of existing potential field geophysical data, it is suggested that the structural ductile grain of the region is controlled by large, c. EW trending shear zones with an overall sinistral strike-slip kinematics. The Oskarshamn Shear Zone (OSZ) and the Mederhult lineament are two examples of these shear zones and it is proposed that the ductile lineaments mapped in Laxemar-Simpevarp are genetically linked to shearing accommodated by these shear zones. The structural interpretation of the geophysical imagery of the Laxemar-Simpevarp regional model area and the available meso-scale structural information indicate that the Laxemar-Simpevarp study area can be interpreted as the analogue of a large-scale S/C' structural pattern. In detail, the Aespoe shear zone and other similarly oriented ductile shears represent C' shear bands that deform sinistrally the intervening EW lineaments (the S surfaces), which locally are significantly crenulated/folded in response to their asymptotic bending into the C' shears. This geometric and kinematic interpretation implies that, in contrast to existing reconstructions and models, EW- and not NE-trending shear zones become the main structural ductile feature of the region. Shear forces acting parallel to these main zones can successfully explain all the ductile structures described and reported from the area. The greatest compressive stress at the time of ductile shearing would trend NE-SW. The brittle deformation history of the region is complex and results from the multiple reactivation of fracture- and fault sets caused by the many orogenic episodes that affected the area during 1.5 Gyr of geological brittle evolution. Fault-slip data from outcrops and oriented drill cores were used to compute paleo-stress states. In the general absence of time markers that help constrain

  17. Regional hydrogeological simulations. Numerical modelling using ConnectFlow. Preliminary site description Simpevarp sub area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, Lee; Hoch, Andrew; Hunter, Fiona; Jackson, Peter [Serco Assurance, Risley (United Kingdom); Marsic, Niko [Kemakta Konsult, Stockholm (Sweden)

    2005-02-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) carries out site investigations in two different candidate areas in Sweden with the objective of describing the in situ conditions for a bedrock repository for spent nuclear fuel. The two candidate areas are named Forsmark and Simpevarp. The site characterisation work is divided into two phases, an initial site investigation phase (IPLU) and a complete site investigation phase (KPLU). The results of IPLU are used as a basis for deciding on a subsequent KPLU phase. On the basis of the KPLU investigations a decision is made as to whether detailed characterisation will be performed (including sinking of a shaft).An integrated component in the site characterisation work is the development of site descriptive models. These comprise basic models in three dimensions with an accompanying text description. Central in the modelling work is the geological model which provides the geometrical context in terms of a model of deformation zones and the rock mass between the zones. Using the geological and geometrical description models as a basis, descriptive models for other geo-disciplines (hydrogeology, hydro-geochemistry, rock mechanics, thermal properties and transport properties) will be developed. Great care is taken to arrive at a general consistency in the description of the various models and assessment of uncertainty and possible needs of alternative models.Here, a numerical model is developed on a regional-scale (hundreds of square kilometres) to understand the zone of influence for groundwater flow that effects the Simpevarp area. Transport calculations are then performed by particle tracking from a local-scale release area (tens of square kilometres) to identify potential discharge areas for the site. The transport from the two site-scale release areas (a few square kilometres) at the Simpevarp site and the Laxemar site are also considered more specifically and using greater grid resolution.The main

  18. Geological evolution, palaeoclimate and historical development of the Forsmark and Laxemar-Simpevarp areas. Site descriptive modelling SDM-Site

    Energy Technology Data Exchange (ETDEWEB)

    Soederbaeck, Bjoern [ed.

    2008-06-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The site investigations started in 2002 and were completed in 2007. The analysis and modelling of data from the site investigations, which have taken place during and after these investigations, provide a foundation for the development of an integrated, multidisciplinary site descriptive model (SDM) for each of the two sites. A site descriptive model constitutes a description of the site and its regional setting, covering the current state of the geosphere and the biosphere, as well as those natural processes that affect or have affected their long-term development. Hitherto, a number of reports presenting preliminary site descriptive models for Forsmark and Laxemar-Simpevarp have been published. In these reports, the evolutionary and historical aspects of the site were included in a separate chapter. The present report comprises a further elaboration of the evolutionary and historical information included in the preliminary SDM reports, but presented here in a separate, supplementary report to the final site description, SDM-Site. The report is common to the two investigated areas, and the overall objective is to describe the long-term geological evolution, the palaeoclimate, and the post-glacial development of ecosystems and of the human population at the two sites. The report largely consists of a synthesis of information derived from the scientific literature and other sources not related to the site investigations. However, considerable information from the site investigations that has contributed to our understanding of the past development at each site is also included. This unique synthesis of both published information in a regional perspective and new site-specific information breaks new ground in our understanding

  19. Geological evolution, palaeoclimate and historical development of the Forsmark and Laxemar-Simpevarp areas. Site descriptive modelling SDM-Site

    International Nuclear Information System (INIS)

    Soederbaeck, Bjoern

    2008-06-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The site investigations started in 2002 and were completed in 2007. The analysis and modelling of data from the site investigations, which have taken place during and after these investigations, provide a foundation for the development of an integrated, multidisciplinary site descriptive model (SDM) for each of the two sites. A site descriptive model constitutes a description of the site and its regional setting, covering the current state of the geosphere and the biosphere, as well as those natural processes that affect or have affected their long-term development. Hitherto, a number of reports presenting preliminary site descriptive models for Forsmark and Laxemar-Simpevarp have been published. In these reports, the evolutionary and historical aspects of the site were included in a separate chapter. The present report comprises a further elaboration of the evolutionary and historical information included in the preliminary SDM reports, but presented here in a separate, supplementary report to the final site description, SDM-Site. The report is common to the two investigated areas, and the overall objective is to describe the long-term geological evolution, the palaeoclimate, and the post-glacial development of ecosystems and of the human population at the two sites. The report largely consists of a synthesis of information derived from the scientific literature and other sources not related to the site investigations. However, considerable information from the site investigations that has contributed to our understanding of the past development at each site is also included. This unique synthesis of both published information in a regional perspective and new site-specific information breaks new ground in our understanding

  20. Preliminary site description: Groundwater flow simulations. Simpevarp area (version 1.1) modelled with CONNECTFLOW

    International Nuclear Information System (INIS)

    Hartley, Lee; Worth, David; Gylling, Bjoern; Marsic, Niko; Holmen, Johan

    2004-08-01

    The main objective of this study is to assess the role of known and unknown hydrogeological conditions for the present-day distribution of saline groundwater at the Simpevarp and Laxemar sites. An improved understanding of the paleo-hydrogeology is necessary in order to gain credibility for the Site Descriptive Model in general and the Site Hydrogeological Description in particular. This is to serve as a basis for describing the present hydrogeological conditions as well as predictions of future hydrogeological conditions. This objective implies a testing of: geometrical alternatives in the structural geology and bedrock fracturing, variants in the initial and boundary conditions, and parameter uncertainties (i.e. uncertainties in the hydraulic property assignment). This testing is necessary in order to evaluate the impact on the groundwater flow field of the specified components and to promote proposals of further investigations of the hydrogeological conditions at the site. The general methodology for modelling transient salt transport and groundwater flow using CONNECTFLOW that was developed for Forsmark has been applied successfully also for Simpevarp. Because of time constraints only a key set of variants were performed that focussed on the influences of DFN model parameters, the kinematic porosity, and the initial condition. Salinity data in deep boreholes available at the time of the project was too limited to allow a good calibration exercise. However, the model predictions are compared with the available data from KLX01 and KLX02 below. Once more salinity data is available it may be possible to draw more definite conclusions based on the differences between variants. At the moment though the differences should just be used understand the sensitivity of the models to various input parameters

  1. Hydrogeochemical evaluation of the Simpevarp area, model version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (ed.) [Geopoint AB, Stockholm (Sweden); Smellie, John [Conterra AB, Uppsala (Sweden); Gimeno, Maria; Auque, Luis; Gomez, Javier [Univ. of Zaragoza (Spain). Dept. of Earth Sciences; Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Gurban, Ioana [3D-Terra (Sweden)

    2004-02-01

    Siting studies for SKB's programme of deep geological disposal of nuclear fuel waste currently involves the investigation of two locations, Simpevarp and Forsmark, on the eastern coast of Sweden to determine their geological, hydrogeochemical and hydrogeological characteristics. Present work completed has resulted in model version 1.1 which represents the first evaluation of the available Simpevarp groundwater analytical data collected up to July 1st, 2003 (i.e. the first 'data freeze' of the site). The HAG (Hydrochemical Analytical Group) group had access to a total of 535 water samples collected from the surface and sub-surface environment (e.g. soil pipes in the overburden, streams and lakes); only a few samples were collected from drilled boreholes. The deepest fracture groundwater samples with sufficient analytical data reflected depths down to 250 m. Furthermore, most of the waters sampled (79%) lacked crucial analytical information that restricted the evaluation. Consequently, model version 1.1 focussed on the processes taking place in the uppermost part of the bedrock rather than at repository levels. The complex groundwater evolution and patterns at Simpevarp are a result of many factors such as: a) the flat topography and proximity to the Baltic Sea, b) changes in hydrogeology related to glaciation/deglaciation and land uplift, c) repeated marine/lake water regressions/transgressions, and d) organic or inorganic alteration of the groundwater composition caused by microbial processes or water/rock interactions. The sampled groundwaters reflect to various degrees of modern or ancient water/rock interactions and mixing processes. Higher topography to the west of Simpevarp has resulted in hydraulic gradients which have partially flushed out old water types. Except for sea waters, most surface waters and some groundwaters from percussion boreholes are fresh, non-saline waters according to the classification used for Aespoe groundwaters. The rest

  2. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    Energy Technology Data Exchange (ETDEWEB)

    Follin, Sven [SF GeoLogic AB, Stockholm (Sweden); Stigsson, Martin; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Svensson, Urban [Computer-aided Fluid Engineering AB, Norrkoeping (Sweden)

    2004-12-01

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  3. Variable-density groundwater flow simulations and particle tracking. Numerical modelling using DarcyTools. Preliminary site description of the Simpevarp area, version 1.1

    International Nuclear Information System (INIS)

    Follin, Sven; Stigsson, Martin; Berglund, Sten; Svensson, Urban

    2004-12-01

    SKB is conducting site investigations for a high-level nuclear waste repository in fractured crystalline rocks at two coastal areas in Sweden, Forsmark and Simpevarp. The investigations started in 2002 and have been planned since the late 1990s. The work presented here investigates the possibility of using hydrogeochemical measurements in deep boreholes to reduce parameter uncertainty in a regional modelling of groundwater flow in fractured rock. The work was conducted with the aim of improving the palaeohydrogeological understanding of the Simpevarp area and to give recommendations to the preparations of the next version of the Preliminary Site Description (1.2). The study is based on a large number of numerical simulations of transient variable density groundwater flow through a strongly heterogeneous and anisotropic medium. The simulations were conducted with the computer code DarcyTools, the development of which has been funded by SKB. DarcyTools is a flexible porous media code specifically designed to treat groundwater flow and salt transport in sparsely fractured crystalline rock and it is noted that some of the features presented in this report are still under development or subjected to testing and verification. The simulations reveal the sensitivity of the results to different hydrogeological modelling assumptions, e.g. the sensitivity to the initial groundwater conditions at 10,000 BC, the size of the model domain and boundary conditions, and the hydraulic properties of deterministically and stochastically modelled deformation zones. The outcome of these simulations was compared with measured salinities and calculated relative proportions of different water types (mixing proportions) from measurements in two deep core drilled boreholes in the Laxemar subarea. In addition to the flow simulations, the statistics of flow related transport parameters were calculated for particle flowpaths from repository depth to ground surface for two subareas within the

  4. Estimation of residence times of coastal basins in the Laxemar- Simpevarp area between 3000 BC and 9000 AD

    Energy Technology Data Exchange (ETDEWEB)

    Engqvist, Anders (AandI Engqvist Konsult HB, Vaxholm (Sweden))

    2010-09-15

    The assignment has consisted of computation of the morpho- and bathymetry of the coastal area of Laxemar-Simpevarp for the time period 3000 BC through 9000 AD, in order to estimate the residence times as yearly means of volume-averaged specific age (Average Age, AvA) for water in coastal basins. These basins have been selected as belonging to earlier defined biosphere objects, containing anticipated exit points from possible radionuclides leaking from a hypothetical underground repository for spent nuclear fuel. This endeavor starts with partitioning of the coast into appropriate sub-basins interconnected by straits in an as objective manner as possible. This has been performed in cooperation with Umeaa Univ. followed by the transformation of these hypsographical data to a form that can serve as input data to the employed numerical CouBa-model. This model has been developed to simulate the water exchange of straits between densimetrically stably stratified basins with a free sea level including advection and mixing of water-borne conservative scalar properties, e.g. salinity, heat and specific age. The forcing of the model consists of run-off, wind-induced stress, thermal surface dynamics (heating/cooling) and density fluctuations at the open boundary toward the coastal zone, relative by which the specific water age is calculated For these ambient forcing factors there do not exist sufficiently precise climate data other than for contemporary times. For all other time periods the measured and/or model-computed forcing data regarding 2004 have been used. Estimated AvA-values for the different time periods are thus an expression of sub-basin configuration and hypsographical differences. An overriding directive has been to rather overestimate than underestimate the residence times, as to avoid underestimation of the subsequent dose calculations. The results of these AvA computations, presented as volume averages of yearly means of the sixteen biosphere object

  5. Estimation of residence times of coastal basins in the Laxemar-Simpevarp area between 3000 BC and 9000 AD

    International Nuclear Information System (INIS)

    Engqvist, Anders

    2010-09-01

    The assignment has consisted of computation of the morpho- and bathymetry of the coastal area of Laxemar-Simpevarp for the time period 3000 BC through 9000 AD, in order to estimate the residence times as yearly means of volume-averaged specific age (Average Age, AvA) for water in coastal basins. These basins have been selected as belonging to earlier defined biosphere objects, containing anticipated exit points from possible radionuclides leaking from a hypothetical underground repository for spent nuclear fuel. This endeavor starts with partitioning of the coast into appropriate sub-basins interconnected by straits in an as objective manner as possible. This has been performed in cooperation with Umeaa Univ. followed by the transformation of these hypsographical data to a form that can serve as input data to the employed numerical CouBa-model. This model has been developed to simulate the water exchange of straits between densimetrically stably stratified basins with a free sea level including advection and mixing of water-borne conservative scalar properties, e.g. salinity, heat and specific age. The forcing of the model consists of run-off, wind-induced stress, thermal surface dynamics (heating/cooling) and density fluctuations at the open boundary toward the coastal zone, relative by which the specific water age is calculated For these ambient forcing factors there do not exist sufficiently precise climate data other than for contemporary times. For all other time periods the measured and/or model-computed forcing data regarding 2004 have been used. Estimated AvA-values for the different time periods are thus an expression of sub-basin configuration and hypsographical differences. An overriding directive has been to rather overestimate than underestimate the residence times, as to avoid underestimation of the subsequent dose calculations. The results of these AvA computations, presented as volume averages of yearly means of the sixteen biosphere object

  6. Chemical characteristics of surface systems in the Simpevarp area. Visualisation and statistical evaluation of data from surface water, precipitation, shallow groundwater, and regolith

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-01-15

    The Swedish Nuclear Fuel and Waste management Co (SKB) initiated site investigations for a deep repository for spent nuclear fuel at two different sites in Sweden, Forsmark and Oskarshamn, in 2002. This report evaluates the results from chemical investigations of the surface system in the Simpevarp area in Oskarshamn, i.e. both the Laxemar subarea and the Simpevarp subarea, during the period Nov 2002 - Mar 2005. The evaluation includes data from surface waters (lakes, streams and the sea), precipitation, shallow groundwater and regolith (till, soil, peat, sediments and biota) in the area. The main focus of the study is to visualize the vast amount of data collected hitherto in the site investigations, and to give a chemical characterisation of the investigated media at the site. The results will be used to support the site descriptive models, which in turn are used for safety assessment studies and for the environmental impact assessment. The data used consist of water chemical composition in lakes, streams and coastal sites, and in precipitation, predominantly sampled on a monthly basis, and in groundwater from soil tubes and wells. Moreover, regolith data includes information on the chemical composition of till, soil, sediment and vegetation samples from the area. The characterisations include all measured chemical parameters, i.e. major and minor constituents, trace elements, nutrients, isotopes and radio nuclides, as well as field measured parameters. The evaluation of data from each medium has been divided into the following parts: Characterisation of individual sampling sites, and comparisons within and among sampling sites as well as comparisons with local, regional and national reference data. Analysis of time trends and seasonal variation (for surface waters). Exploration of relationships among the various chemical parameters. For all investigated parameters, the report presents selected statistics for each sampling site, as well as for available reference

  7. Chemical characteristics of surface systems in the Simpevarp area. Visualisation and statistical evaluation of data from surface water, precipitation, shallow groundwater, and regolith

    International Nuclear Information System (INIS)

    Troejbom, Mats; Soederbaeck, Bjoern

    2006-01-01

    The Swedish Nuclear Fuel and Waste management Co (SKB) initiated site investigations for a deep repository for spent nuclear fuel at two different sites in Sweden, Forsmark and Oskarshamn, in 2002. This report evaluates the results from chemical investigations of the surface system in the Simpevarp area in Oskarshamn, i.e. both the Laxemar subarea and the Simpevarp subarea, during the period Nov 2002 - Mar 2005. The evaluation includes data from surface waters (lakes, streams and the sea), precipitation, shallow groundwater and regolith (till, soil, peat, sediments and biota) in the area. The main focus of the study is to visualize the vast amount of data collected hitherto in the site investigations, and to give a chemical characterisation of the investigated media at the site. The results will be used to support the site descriptive models, which in turn are used for safety assessment studies and for the environmental impact assessment. The data used consist of water chemical composition in lakes, streams and coastal sites, and in precipitation, predominantly sampled on a monthly basis, and in groundwater from soil tubes and wells. Moreover, regolith data includes information on the chemical composition of till, soil, sediment and vegetation samples from the area. The characterisations include all measured chemical parameters, i.e. major and minor constituents, trace elements, nutrients, isotopes and radio nuclides, as well as field measured parameters. The evaluation of data from each medium has been divided into the following parts: Characterisation of individual sampling sites, and comparisons within and among sampling sites as well as comparisons with local, regional and national reference data. Analysis of time trends and seasonal variation (for surface waters). Exploration of relationships among the various chemical parameters. For all investigated parameters, the report presents selected statistics for each sampling site, as well as for available reference

  8. Prediction of the existence or fine-grained granite dykes in the Simpevarp area; Prediktering av foerekomst av finkorniga granitgaangar i Simpevarpsomraadet

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Haakan; Triumf, Carl-Axel [GeoVista AB, Luleaa (Sweden); Wahlgren, Carl-Henric [Geological Survey of Sweden, Uppsala (Sweden)

    2002-11-01

    Fine-grained granite dykes associated with a high fracture frequency occur in the bedrock of the Simpevarp region. In order to avoid problems in a future storage for nuclear waste it is important to find methods to detect areas where the dykes occur frequently. The aim of this project is to test the possibility to use airborne gamma ray spectrometry in the Simpevarp region to distinguish between different areas of the bedrock containing a varying frequency of fine-grained granite dykes. Investigations were also made to test if and how plastic deformation and a thin cover of moss affect the radiometric signature of the rocks. Ground measurements with a gamma ray spectrometer were performed on the islands of Aespoe, Aevroe and at the Simpevarp peninsula on different kinds of Smaaland granite with varying frequencies of fine-grained granite dykes. Reference measurements were performed on rocks without granite dykes. The bedrock at the measurement sites was geologically characterized in connection to the measurements. Air borne radiometric data (uranium, potassium and thorium) measured by the Geological Survey of Sweden in 1986 (flight altitude 30 m, point distance 40 m, line spacing 200 m) was compared to the existing bedrock map of the area and also to existing observation sites of fine-grained granite dykes. The ground measurements with gamma ray spectrometer clearly indicate that the fine-grained granite dykes have a specific radiometric signature compared to the granite-granodiorite at Aevroe and the quartzmonzodiorite-granodiorite at Aespoe. The main difference between the dykes and the other investigated rocks is seen in the thorium content, which is typically 3-5 times greater in the fine grained granite dykes. A thin cover of moss does not seem to significantly affect the radiometric signal of the bedrock, and neither does plastic deformation. However, the number of measurements on deformed and on covered rocks is low. The radiometric anomaly pattern shown in

  9. Simpevarp - site descriptive model version 0

    International Nuclear Information System (INIS)

    2002-11-01

    During 2002, SKB is starting detailed investigations at two potential sites for a deep repository in the Precambrian rocks of the Fennoscandian Shield. The present report concerns one of those sites, Simpevarp, which lies in the municipality of Oskarshamn, on the southeast coast of Sweden, about 250 kilometres south of Stockholm. The site description will have two main components: a written synthesis of the site, summarising the current state of knowledge, as documented in the databases containing the primary data from the site investigations, and one or several site descriptive models, in which the collected information is interpreted and presented in a form which can be used in numerical models for rock engineering, environmental impact and long-term safety assessments. SKB maintains two main databases at the present time, a site characterisation database called SICADA and a geographic information system called SKB GIS. The site descriptive model will be developed and presented with the aid of the SKB GIS capabilities, and with SKBs Rock Visualisation System (RVS), which is also linked to SICADA. The version 0 model forms an important framework for subsequent model versions, which are developed successively, as new information from the site investigations becomes available. Version 0 is developed out of the information available at the start of the site investigation. In the case of Simpevarp, this is essentially the information which was compiled for the Oskarshamn feasibility study, which led to the choice of that area as a favourable object for further study, together with information collected since its completion. This information, with the exception of the extensive data base from the nearby Aespoe Hard Rock Laboratory, is mainly 2D in nature (surface data), and is general and regional, rather than site-specific, in content. Against this background, the present report consists of the following components: an overview of the present content of the databases

  10. Preliminary site description Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, Anders [ed.

    2005-04-01

    The objectives of the version 1.2 site descriptive modelling (SDM) of the Simpevarp subarea are to produce and document an integrated description of the site and its regional environments based on the site-specific data available from the initial site investigations and to give recommendations on continued investigations on a continuous basis. The modelling work is based on primary data available at the time of the data freeze for Simpevarp 1.2, April 1, 2004. The local scale model area (24 km{sup 2}) for the Simpevarp 1.2 modelling encompasses both the Simpevarp and Laxemar subareas. The local model area is located in the centre of a regional scale model area (273 km{sup 2}). Surface ecosystem models in terms of pools and fluxes of carbon have been developed for the terrestrial (e.g. plants and animals) and limnic (e.g. algae and fish) systems using the Lake Frisksjoen drainage area. Furthermore, a first marine ecosystem model has been developed for the Basin Borholmsfjaerden. Three principal lithological domains have been defined in the subarea, an A domain that is dominated by the Aevroe granite, a domain B that is dominated by the fine-grained dioritoid, a C domain that is characterised by a mixture of of Aevroe granite and quartz monzodiorite. A fourth domain is made up a few scattered domains of diorite to gabbro. In total, 22 deformation zones with high confidence of occurrence have been interpreted in the local scale model area. The understanding of the interpreted deformation zones of the Simpevarp subarea is considered adequate to make a preliminary assessment of available storage volumes for a deep repository. High rock stresses do not appear to be a major concern for the Simpevarp subarea. The magnitude of the maximum principal stress at 500 m in the Simpevarp subarea is estimated at 10-22 MPa. The analysis of the thermal conductivity has developed considerably since Simpevarp 1.1. In terms of interpreted mean values for the identified lithological

  11. Preliminary site description Simpevarp subarea - version 1.2

    International Nuclear Information System (INIS)

    Winberg, Anders

    2005-04-01

    The objectives of the version 1.2 site descriptive modelling (SDM) of the Simpevarp subarea are to produce and document an integrated description of the site and its regional environments based on the site-specific data available from the initial site investigations and to give recommendations on continued investigations on a continuous basis. The modelling work is based on primary data available at the time of the data freeze for Simpevarp 1.2, April 1, 2004. The local scale model area (24 km 2 ) for the Simpevarp 1.2 modelling encompasses both the Simpevarp and Laxemar subareas. The local model area is located in the centre of a regional scale model area (273 km 2 ). Surface ecosystem models in terms of pools and fluxes of carbon have been developed for the terrestrial (e.g. plants and animals) and limnic (e.g. algae and fish) systems using the Lake Frisksjoen drainage area. Furthermore, a first marine ecosystem model has been developed for the Basin Borholmsfjaerden. Three principal lithological domains have been defined in the subarea, an A domain that is dominated by the Aevroe granite, a domain B that is dominated by the fine-grained dioritoid, a C domain that is characterised by a mixture of of Aevroe granite and quartz monzodiorite. A fourth domain is made up a few scattered domains of diorite to gabbro. In total, 22 deformation zones with high confidence of occurrence have been interpreted in the local scale model area. The understanding of the interpreted deformation zones of the Simpevarp subarea is considered adequate to make a preliminary assessment of available storage volumes for a deep repository. High rock stresses do not appear to be a major concern for the Simpevarp subarea. The magnitude of the maximum principal stress at 500 m in the Simpevarp subarea is estimated at 10-22 MPa. The analysis of the thermal conductivity has developed considerably since Simpevarp 1.1. In terms of interpreted mean values for the identified lithological domains, the

  12. Human population and activities at Simpevarp. Site description

    International Nuclear Information System (INIS)

    Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt

    2004-12-01

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km 2 near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km 2 , three times lower than in Kalmar laen. The demography statistics show

  13. Human population and activities at Simpevarp. Site description

    Energy Technology Data Exchange (ETDEWEB)

    Miliander, Sofia; Punakivi, Mari; Kylaekorpi, Lasse; Rydgren, Bernt [SwedPower AB, Stockholm (Sweden)

    2004-12-01

    The Swedish Nuclear Fuel and Waste Management Co (SKB) is in the process of selecting a safe and environmentally acceptable location for a deep repository of radioactive waste. Two alternative locations are under investigation. These are Forsmark, Oesthammars kommun (kommun = municipality) and Simpevarp/Laxemar, Oskarshamns kommun. SKB has expressed the importance of describing the humans and their activities in these areas and therefore has this synthesis concerning the human population in Forsmark been produced. The description is a statistical synthesis, mainly based upon statistical data from SCB (Statistics Sweden) that has been collected, processed and analysed. The statistical data has not been verified through site inspections and interviews. When using statistical data, it is advisable to note that the data becomes more unreliable if the areas are small, with small populations. The data in this description is essential for future evaluations of the impact on the environment and its human population (environmental impacts assessments). The data is also important when modelling the potential flows of radio nuclides and calculating the risk of exposure in future safety assessments. The actual area for the study is in this report called 'the Simpevarp area', an area of 127.0 km{sup 2} near Oskarshamn nuclear power plant. The land use in Simpevarp area differs notably from the land use in Kalmar laen. The forest area is far more dominating in Simpevarp area than in Kalmar laen and it represents as much as 89% compared to 63% of the total area. Only 4.4% of the area is arable land compared to 11.6% in Kalmar laen and only 0.3% is of other type (wetlands, bare rock, quarries, pites etc) compared to 15.6% in the county. The main observation is that Simpevarp area is a sparsely populated area located in a relatively lightly populated county. In 2002, the population density was 7.4 inhabitants/km{sup 2}, three times lower than in Kalmar laen. The

  14. Simpevarp - site descriptive model version 0

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-11-01

    During 2002, SKB is starting detailed investigations at two potential sites for a deep repository in the Precambrian rocks of the Fennoscandian Shield. The present report concerns one of those sites, Simpevarp, which lies in the municipality of Oskarshamn, on the southeast coast of Sweden, about 250 kilometres south of Stockholm. The site description will have two main components: a written synthesis of the site, summarising the current state of knowledge, as documented in the databases containing the primary data from the site investigations, and one or several site descriptive models, in which the collected information is interpreted and presented in a form which can be used in numerical models for rock engineering, environmental impact and long-term safety assessments. SKB maintains two main databases at the present time, a site characterisation database called SICADA and a geographic information system called SKB GIS. The site descriptive model will be developed and presented with the aid of the SKB GIS capabilities, and with SKBs Rock Visualisation System (RVS), which is also linked to SICADA. The version 0 model forms an important framework for subsequent model versions, which are developed successively, as new information from the site investigations becomes available. Version 0 is developed out of the information available at the start of the site investigation. In the case of Simpevarp, this is essentially the information which was compiled for the Oskarshamn feasibility study, which led to the choice of that area as a favourable object for further study, together with information collected since its completion. This information, with the exception of the extensive data base from the nearby Aespoe Hard Rock Laboratory, is mainly 2D in nature (surface data), and is general and regional, rather than site-specific, in content. Against this background, the present report consists of the following components: an overview of the present content of the databases

  15. Execution programme for the initial site investigations at Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-10-01

    In the feasibility studies that were completed in 2001, eight sites were identified as potentially suitable for hosting a repository. All the identified sites meet the safety requirements with respect to bedrock conditions that could be checked at that time. The feasibility studies have revealed good potential when it comes to the technical and environmental aspects as well. Based on an integrated evaluation SKB proposed to start site investigations with test drillings at three sites; Simpevarp, Forsmark, and Tierp north. The site investigations have started at Simpevarp and Forsmark. The municipal council of Tierp rejected a site investigation in April 2002. The site investigations are divided into two main phases; initial and complete investigations. Initial Site Investigation is performed to identify the site within a specified area that is deemed to be most suitable for a deep repository and to determine whether the feasibility study's judgement of the suitability of the area holds up in the light of borehole data from repository depth. The Initial Site Investigation is expected to take about 3 years. If the assessment shows that the site has good potential to host a repository, Complete Site Investigation will follow for an expected duration of another 3 years. The purpose of the Complete Site Investigation is to gather all information required to select one of the sites as the main alternative and to apply for a permit for construction of the deep repository at that site. The site-specific programme gives an overview of the whole site investigation phase as well as a detailed description of the initial stage. The results of the initial investigations will determine whether Simpevarp is appropriate for further investigation, i.e. the Complete Site Investigation. This document summarizes the investigations that will be carried out at Simpevarp during the Initial Site Investigations. The document is a working document, which will be successively updated as

  16. Execution programme for the initial site investigations at Simpevarp

    International Nuclear Information System (INIS)

    2002-10-01

    In the feasibility studies that were completed in 2001, eight sites were identified as potentially suitable for hosting a repository. All the identified sites meet the safety requirements with respect to bedrock conditions that could be checked at that time. The feasibility studies have revealed good potential when it comes to the technical and environmental aspects as well. Based on an integrated evaluation SKB proposed to start site investigations with test drillings at three sites; Simpevarp, Forsmark, and Tierp north. The site investigations have started at Simpevarp and Forsmark. The municipal council of Tierp rejected a site investigation in April 2002. The site investigations are divided into two main phases; initial and complete investigations. Initial Site Investigation is performed to identify the site within a specified area that is deemed to be most suitable for a deep repository and to determine whether the feasibility study's judgement of the suitability of the area holds up in the light of borehole data from repository depth. The Initial Site Investigation is expected to take about 3 years. If the assessment shows that the site has good potential to host a repository, Complete Site Investigation will follow for an expected duration of another 3 years. The purpose of the Complete Site Investigation is to gather all information required to select one of the sites as the main alternative and to apply for a permit for construction of the deep repository at that site. The site-specific programme gives an overview of the whole site investigation phase as well as a detailed description of the initial stage. The results of the initial investigations will determine whether Simpevarp is appropriate for further investigation, i.e. the Complete Site Investigation. This document summarizes the investigations that will be carried out at Simpevarp during the Initial Site Investigations. The document is a working document, which will be successively updated as

  17. The marine ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

    International Nuclear Information System (INIS)

    Aquilonius, Karin

    2010-12-01

    The overall objective of this report is to provide a thorough description of the marine ecosystems at the sites Forsmark and Laxemar-Simpevarp, to identify processes in these ecosystems of importance to transfer and accumulation of radionuclides and, finally based on this knowledge, develop parameters to be used for the marine ecosystem in the safety analysis SR-Site. The report includes a thorough description of the major components in the marine ecosystems in Forsmark and Laxemar-Simpevarp, and covers the following areas: chemical and physical characteristics, climate and meteorology, morphology and regolith, biota in the marine ecosystem, human impact, water exchange and historical evolution at the sites. The site specific characteristics are compared with marine data from the Baltic region. Marine ecosystem modeling and mass balances calculations for carbon and a number of other elements were carried out to further improve the understanding of the marine ecosystems. Important processes for the safety assessment are identified, described and evaluated according to a systematic method. The derivation of marine ecosystem parameters and the resulting parameters is presented. The last chapter of the report aims at summarizing the knowledge of the marine ecosystems at the two areas. In comparison with the Gulf of Bothnia and the Baltic Proper, salinity is somewhat lower in Forsmark and Laxemar-Simpevarp respectively. The nitrogen and phosphorus levels at the two sites are low to moderately high compared with environmental monitoring data for corresponding areas in the Baltic Sea. In Forsmark, nitrogen seems to be the limiting nutrient during the summer months. In Laxemar-Simpevarp, nitrogen seems to be the limiting nutrient in the outer areas and phosphorus in the inner bays. This coincides with the general conditions in the Bothnian Sea (Forsmark) and the Baltic Proper (Laxemar-Simpevarp). The annual mean water temperature in Forsmark is slightly higher than the

  18. The marine ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Aquilonius, Karin [ed.; Studsvik Nuclear AB (Sweden)

    2010-12-15

    The overall objective of this report is to provide a thorough description of the marine ecosystems at the sites Forsmark and Laxemar-Simpevarp, to identify processes in these ecosystems of importance to transfer and accumulation of radionuclides and, finally based on this knowledge, develop parameters to be used for the marine ecosystem in the safety analysis SR-Site. The report includes a thorough description of the major components in the marine ecosystems in Forsmark and Laxemar-Simpevarp, and covers the following areas: chemical and physical characteristics, climate and meteorology, morphology and regolith, biota in the marine ecosystem, human impact, water exchange and historical evolution at the sites. The site specific characteristics are compared with marine data from the Baltic region. Marine ecosystem modeling and mass balances calculations for carbon and a number of other elements were carried out to further improve the understanding of the marine ecosystems. Important processes for the safety assessment are identified, described and evaluated according to a systematic method. The derivation of marine ecosystem parameters and the resulting parameters is presented. The last chapter of the report aims at summarizing the knowledge of the marine ecosystems at the two areas. In comparison with the Gulf of Bothnia and the Baltic Proper, salinity is somewhat lower in Forsmark and Laxemar-Simpevarp respectively. The nitrogen and phosphorus levels at the two sites are low to moderately high compared with environmental monitoring data for corresponding areas in the Baltic Sea. In Forsmark, nitrogen seems to be the limiting nutrient during the summer months. In Laxemar-Simpevarp, nitrogen seems to be the limiting nutrient in the outer areas and phosphorus in the inner bays. This coincides with the general conditions in the Bothnian Sea (Forsmark) and the Baltic Proper (Laxemar-Simpevarp). The annual mean water temperature in Forsmark is slightly higher than the

  19. The limnic ecosystems at Forsmark and Laxemar-Simpevarp

    International Nuclear Information System (INIS)

    Andersson, Eva

    2010-12-01

    The overall objective of this report is to describe the limnic ecosystems at Forsmark and Laxemar- Simpevarp, identify important processes in a radionuclide perspective and provide a description of the radionuclide model for the biosphere used in SR-Site. The report includes a thorough description of the lakes and streams in Forsmark and Laxemar- Simpevarp and covers the following areas: catchment area characteristics, hydrology, climate, sediment characteristics, physical characteristics of streams, habitat distribution in lakes, biotic components (biomass as well as production), water chemistry, and comparison with other lakes and streams in the region, and a historical description. Ecosystem models for carbon and mass balances for a number of elements have been calculated to further improve the understanding of the lake ecosystems. Important processes for the safety assessment are described and evaluated in the report. A separate chapter is included to specifically describe how and where these processes are included in the radionuclide model. The radionuclide model is described and parameterisation and guidance to parameter calculation is provided. The last chapter of the report provides a summary of the knowledge of the limnic systems at the two areas. The Forsmark regional model area contains more than 25 permanent lakes and pools. All lakes are small and shallow, and are characterized as oligotrophic hardwater lakes. Calcareous soils in the area give rise to high calcium concentrations in the surface water, which in turn leads to high pH and low nutrient concentrations in water as phosphorus often co-precipitates with calcium. The shallow depths and moderate water colour permit photosynthesis in the entire benthic habitat of the lakes, and the bottoms are covered by dense stands of the macroalgae Chara sp. Moreover, many of the lakes also have a thick microbial mat (>10 cm), consisting of cyanobacteria and diatoms, in the benthic habitat. Fish in the lakes

  20. The limnic ecosystems at Forsmark and Laxemar-Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Eva

    2010-12-15

    The overall objective of this report is to describe the limnic ecosystems at Forsmark and Laxemar- Simpevarp, identify important processes in a radionuclide perspective and provide a description of the radionuclide model for the biosphere used in SR-Site. The report includes a thorough description of the lakes and streams in Forsmark and Laxemar- Simpevarp and covers the following areas: catchment area characteristics, hydrology, climate, sediment characteristics, physical characteristics of streams, habitat distribution in lakes, biotic components (biomass as well as production), water chemistry, and comparison with other lakes and streams in the region, and a historical description. Ecosystem models for carbon and mass balances for a number of elements have been calculated to further improve the understanding of the lake ecosystems. Important processes for the safety assessment are described and evaluated in the report. A separate chapter is included to specifically describe how and where these processes are included in the radionuclide model. The radionuclide model is described and parameterisation and guidance to parameter calculation is provided. The last chapter of the report provides a summary of the knowledge of the limnic systems at the two areas. The Forsmark regional model area contains more than 25 permanent lakes and pools. All lakes are small and shallow, and are characterized as oligotrophic hardwater lakes. Calcareous soils in the area give rise to high calcium concentrations in the surface water, which in turn leads to high pH and low nutrient concentrations in water as phosphorus often co-precipitates with calcium. The shallow depths and moderate water colour permit photosynthesis in the entire benthic habitat of the lakes, and the bottoms are covered by dense stands of the macroalgae Chara sp. Moreover, many of the lakes also have a thick microbial mat (>10 cm), consisting of cyanobacteria and diatoms, in the benthic habitat. Fish in the lakes

  1. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. Site descriptive modelling SDM site

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders [EcoAnalytica, Haegersten (Sweden); ed.

    2008-12-15

    This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing ecological data and data from disciplines such as hydrology, quaternary geology and chemistry. The description therefore includes a number of different processes that drive element fluxes in the ecosystems, such as net primary production, heterotrophic respiration, transpiration, and horizontal transport from land to streams and lakes. Moreover, the human appropriation of the landscape is described with regard to land use and potential and actual utilization of food resources both today and in a historical perspective

  2. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders [ed.; EcoAnalytica, Haegersten (Sweden)

    2010-12-15

    The ecosystem is in most cases the link between radionuclides released from a repository and the exposure of humans and other biota to them. This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing and performing cross-disciplinary analyses of data from a large number of reports produced during the site investigations, Figure 1-2. The report describes the terrestrial landscape, divided here into the three main categories: forests, wetlands and agriculture land, by identifying properties that are important for element accumulation and transport

  3. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

    International Nuclear Information System (INIS)

    Loefgren, Anders

    2010-12-01

    The ecosystem is in most cases the link between radionuclides released from a repository and the exposure of humans and other biota to them. This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing and performing cross-disciplinary analyses of data from a large number of reports produced during the site investigations, Figure 1-2. The report describes the terrestrial landscape, divided here into the three main categories: forests, wetlands and agriculture land, by identifying properties that are important for element accumulation and transport

  4. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. Site descriptive modelling SDM site

    International Nuclear Information System (INIS)

    Loefgren, Anders

    2008-12-01

    This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing ecological data and data from disciplines such as hydrology, quaternary geology and chemistry. The description therefore includes a number of different processes that drive element fluxes in the ecosystems, such as net primary production, heterotrophic respiration, transpiration, and horizontal transport from land to streams and lakes. Moreover, the human appropriation of the landscape is described with regard to land use and potential and actual utilization of food resources both today and in a historical perspective

  5. Expected extreme sea levels at Forsmark and Laxemar-Simpevarp up until year 2100

    International Nuclear Information System (INIS)

    Brydsten, Lars; Engqvist, Anders; Naeslund, Jens-Ove; Lindborg, Tobias

    2009-01-01

    Literature data on factors that can affect the highest expected shoreline during the operational lifetime of a final repository up until ca 2100 AD have been compiled for Forsmark and Laxemar/Simpevarp. The study takes into consideration eustasy (global sea level), isostasy (isostatic rebound) and their trends, as well as regional (North Sea) and local (Baltic Sea) annual extremes of today's sea levels and those in year 2100. The most uncertain factor of these is the future global sea level change. For this factor, three possible scenarios have been included from the literature, forming an rough uncertainty interval around a case with an 'intermediate' global sea level. To this end, the study thus makes use of information on global sea level change that has been published since the IPCC's (UN Intergovernmental Panel on Climate Change) most recent report (2007). The local cumulative impact on the shoreline of the eustatic and isostatic components for both the Forsmark and Laxemar/Simpevarp coastal areas is that the maximum sea level occurs at the end of the investigation period, by year 2100. The interaction of these estimates is discussed in terms of coastal oceanographic aspects and estimated return periods for local extreme sea level-impacting events, including estimated storm surge. Maximum sea levels in year 2100 based on the sea level rise estimates by Rahmstorf are + 254 cm for Forsmark and + 297 cm for Laxemar/Simpevarp, both of these levels with an uncertainty interval of about ± 70 cm. The numbers apply for the worst possible case in regard to future sea level rise, and for occasions of short duration during heavy storms. In this context it is important to note that the data on which these estimates are based are the subject of intense research, and that revisions are therefore to be expected

  6. Expected extreme sea levels at Forsmark and Laxemar-Simpevarp up until year 2100

    Energy Technology Data Exchange (ETDEWEB)

    Brydsten, Lars (Umeaa Univ., Umeaa (Sweden)); Engqvist, Anders (Royal Institute of Technology, Stockholm (Sweden)); Naeslund, Jens-Ove; Lindborg, Tobias (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2009-01-15

    Literature data on factors that can affect the highest expected shoreline during the operational lifetime of a final repository up until ca 2100 AD have been compiled for Forsmark and Laxemar/Simpevarp. The study takes into consideration eustasy (global sea level), isostasy (isostatic rebound) and their trends, as well as regional (North Sea) and local (Baltic Sea) annual extremes of today's sea levels and those in year 2100. The most uncertain factor of these is the future global sea level change. For this factor, three possible scenarios have been included from the literature, forming an rough uncertainty interval around a case with an 'intermediate' global sea level. To this end, the study thus makes use of information on global sea level change that has been published since the IPCC's (UN Intergovernmental Panel on Climate Change) most recent report (2007). The local cumulative impact on the shoreline of the eustatic and isostatic components for both the Forsmark and Laxemar/Simpevarp coastal areas is that the maximum sea level occurs at the end of the investigation period, by year 2100. The interaction of these estimates is discussed in terms of coastal oceanographic aspects and estimated return periods for local extreme sea level-impacting events, including estimated storm surge. Maximum sea levels in year 2100 based on the sea level rise estimates by Rahmstorf are + 254 cm for Forsmark and + 297 cm for Laxemar/Simpevarp, both of these levels with an uncertainty interval of about +- 70 cm. The numbers apply for the worst possible case in regard to future sea level rise, and for occasions of short duration during heavy storms. In this context it is important to note that the data on which these estimates are based are the subject of intense research, and that revisions are therefore to be expected

  7. Description of climate, surface hydrology, and near-surface hydrogeology. Simpevarp 1.2

    International Nuclear Information System (INIS)

    Werner, Kent; Bosson, Emma; Berglund, Sten

    2005-04-01

    This report presents and evaluates the site investigations and primary data on meteorology, surface hydrology and near-surface hydrogeology that are available in the Simpevarp 1.2 'data freeze'. The main objective is to update the previous Simpevarp 1.1 description of the meteorological, surface hydrological and near-surface hydrogeological conditions in the Simpevarp area. Based on the Simpevarp 1.2 dataset, an updated conceptual and descriptive model of the surface and near-surface water flow conditions in the Simpevarp area is presented. In cases where site investigation data are not yet available, regional and/or generic data are used as input to the modelling. GIS- and process-based tools, used for initial quantitative flow modelling, are also presented. The objectives of this initial quantitative modelling are to illustrate, quantify and support the site descriptive model, and also to produce relevant input data to the ecological systems modelling within the SKB SurfaceNet framework.For the Simpevarp 1.2 model, the relevant site investigations include the establishment of one local meteorological station and surface-hydrological stations for discharge measurements, delineation and description of catchment areas, manual discharge measurements in water courses, slug tests in groundwater monitoring wells, and manual groundwater level measurements. In addition, other investigations have also contributed to the modelling, providing data on geometry (including topography), data from surface-based geological investigations and boreholes in Quaternary deposits, and data on the hydrogeological properties of the bedrock. The conceptual and descriptive modelling includes an identification and basic description of type areas, domains and interfaces between domains within the model area. The surface and near-surface flow system is described, including the assignment of hydrogeological properties to HSDs (Hydraulic Soil Domains) of Quaternary deposits based on a

  8. Description of climate, surface hydrology, and near-surface hydrogeology. Simpevarp 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent [SWECO VIAK AB/Golder Associates AB, Stockholm (Sweden); Bosson, Emma; Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2005-04-01

    This report presents and evaluates the site investigations and primary data on meteorology, surface hydrology and near-surface hydrogeology that are available in the Simpevarp 1.2 'data freeze'. The main objective is to update the previous Simpevarp 1.1 description of the meteorological, surface hydrological and near-surface hydrogeological conditions in the Simpevarp area. Based on the Simpevarp 1.2 dataset, an updated conceptual and descriptive model of the surface and near-surface water flow conditions in the Simpevarp area is presented. In cases where site investigation data are not yet available, regional and/or generic data are used as input to the modelling. GIS- and process-based tools, used for initial quantitative flow modelling, are also presented. The objectives of this initial quantitative modelling are to illustrate, quantify and support the site descriptive model, and also to produce relevant input data to the ecological systems modelling within the SKB SurfaceNet framework.For the Simpevarp 1.2 model, the relevant site investigations include the establishment of one local meteorological station and surface-hydrological stations for discharge measurements, delineation and description of catchment areas, manual discharge measurements in water courses, slug tests in groundwater monitoring wells, and manual groundwater level measurements. In addition, other investigations have also contributed to the modelling, providing data on geometry (including topography), data from surface-based geological investigations and boreholes in Quaternary deposits, and data on the hydrogeological properties of the bedrock. The conceptual and descriptive modelling includes an identification and basic description of type areas, domains and interfaces between domains within the model area. The surface and near-surface flow system is described, including the assignment of hydrogeological properties to HSDs (Hydraulic Soil Domains) of Quaternary deposits based on a

  9. The limnic ecosystems at Forsmark and Laxemar-Simpevarp. Site descriptive modelling SDM-Site

    International Nuclear Information System (INIS)

    Norden, Sara; Soederbaeck, Bjoern; Andersson, Eva

    2008-11-01

    The overall objective of this report is to provide a thorough description of the limnic ecosystems at both Forsmark and Laxemar-Simpevarp. This information may be used in the Safety Assessment and as a basis for the Environmental Impact Assessment. Three aims were set up for the report: 1) to characterize and describe the limnic ecosystems today and in the past in the Forsmark and Laxemar-Simpevarp areas and compare these ecosystems with limnic ecosystems in other areas; 2) to evaluate and visualize major pools, fluxes and sinks of elements within the limnic ecosystems; and finally 3) to describe human impact on the limnic ecosystems. The report includes a thorough description of the lakes and streams in Forsmark and Laxemar-Simpevarp and covers the following areas: catchment area characteristics, hydrology, climate, sediment characteristics, physical characteristics of streams, habitat distribution in lakes, biotic components, water chemistry, comparisons with other lakes and streams in the region, and a historical description. Ecosystem models for carbon and mass balances for a number of elements have been calculated to further improve the understanding of the lake ecosystems. Important processes for the safety assessment are described and evaluated in the report. The Forsmark regional model area contains more than 20 permanent lakes and pools. All lakes are small and shallow, and are characterized as oligotrophic hardwater lakes. Calcareous soils in the area give rise to high calcium concentrations in the surface water, which in turn leads to high pH and low nutrient concentrations in water as phosphorus often co-precipitates with calcium. The shallow depths and moderate water colour permit photosynthesis in the entire benthic habitat of the lakes, and the bottoms are covered by dense stands of the macroalgae Chara sp. Moreover, many of the lakes also have a thick microbial mat (>10 cm), consisting of cyanobacteria and diatoms, in the benthic habitat. Fish in

  10. Bedrock transport properties. Preliminary site description Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Byegaard, Johan; Gustavsson, Eva [Geosigma AB, Uppsala (Sweden); Tullborg, Eva-Lena [Terralogica AB, Graabo (Sweden); Berglund, Sten [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2005-06-01

    hydraulically conductive structures are mostly associated with the presence of gouge-filled faults. The mineralogy of the different fracture coatings cannot be correlated to their corresponding host rock type. The hydrogeochemistry has been included in the model by identifying four different groundwater types: (I) fresh diluted Ca-HCO{sub 3} water present in the upper 100 m of the bedrock, (II) groundwater with marine character (Na-(Ca)-Mg-Cl, 5,000 mg/L Cl), (III) groundwater of Na-Ca-Cl type (8,800 mg/L Cl), i.e. present groundwater at repository level in the Simpevarp peninsula, and (IV) brine type water of very high salinity (Ca-Na-Cl type water with Cl content of 45,000 mg/L). The retardation data included in the present model are porosities, diffusivities (expressed in terms of formation factors) and sorption coefficients for intact (non-altered) and altered varieties of the rock types at Simpevarp. Porosities and formation factors have been measured for the major rock types using site specific materials from the Simpevarp area. Mean values for the major rock types have been obtained in the range of 0.17-0.40 vol-% for the porosity and 1. 10{sup -4}-2.9 x 10{sup -4} for the formation factor. Due to lack of site specific sorption data, Kd-values have been imported from previous investigations of Aespoe diorite at Aespoe HRL. This import was justified on the basis of the mineralogical similarity of the major rock types of the Simpevarp site and the Aespoe diorite. Only K{sub d} for the Sr{sup 2+} and Cs{sup +} interaction in a groundwater of type III were available; values of 4.2 x 10{sup -5} m{sup 3}/kg (Sr{sup 2+}) and 0.06 m{sup 3}/kg (Cs{sup +}) were given. The descriptions of bedrock geology and fracture mineralogy are used as a basis for identifying a set of fracture types considered typical for the boreholes in the Simpevarp subarea. Four fracture types were identified and described in terms of geometry (thicknesses of different layers) and retardation parameters

  11. The limnic ecosystems at Forsmark and Laxemar-Simpevarp. Site descriptive modelling SDM-Site

    Energy Technology Data Exchange (ETDEWEB)

    Norden, Sara; Soederbaeck, Bjoern [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Andersson, Eva [SWECO, Stockholm (Sweden)

    2008-11-15

    The overall objective of this report is to provide a thorough description of the limnic ecosystems at both Forsmark and Laxemar-Simpevarp. This information may be used in the Safety Assessment and as a basis for the Environmental Impact Assessment. Three aims were set up for the report: 1) to characterize and describe the limnic ecosystems today and in the past in the Forsmark and Laxemar-Simpevarp areas and compare these ecosystems with limnic ecosystems in other areas; 2) to evaluate and visualize major pools, fluxes and sinks of elements within the limnic ecosystems; and finally 3) to describe human impact on the limnic ecosystems. The report includes a thorough description of the lakes and streams in Forsmark and Laxemar-Simpevarp and covers the following areas: catchment area characteristics, hydrology, climate, sediment characteristics, physical characteristics of streams, habitat distribution in lakes, biotic components, water chemistry, comparisons with other lakes and streams in the region, and a historical description. Ecosystem models for carbon and mass balances for a number of elements have been calculated to further improve the understanding of the lake ecosystems. Important processes for the safety assessment are described and evaluated in the report. The Forsmark regional model area contains more than 20 permanent lakes and pools. All lakes are small and shallow, and are characterized as oligotrophic hardwater lakes. Calcareous soils in the area give rise to high calcium concentrations in the surface water, which in turn leads to high pH and low nutrient concentrations in water as phosphorus often co-precipitates with calcium. The shallow depths and moderate water colour permit photosynthesis in the entire benthic habitat of the lakes, and the bottoms are covered by dense stands of the macroalgae Chara sp. Moreover, many of the lakes also have a thick microbial mat (>10 cm), consisting of cyanobacteria and diatoms, in the benthic habitat. Fish in

  12. Premodelling of the importance of the location of the upstream hydraulic boundary of a regional flow model of the Laxemar-Simpevarp area. Site descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Holmen, Johan G.

    2008-03-01

    The location of the westernmost hydraulic boundary of a regional groundwater flow model representing the Laxemar investigation area is of importance as the regional flow of groundwater is primarily from the west towards the sea (as given by the regional topography). If the westernmost boundary condition of a regional flow model is located to close to the investigation area, the regional flow model may underestimate the magnitude of the regional groundwater flow (at the investigation area), as well as overestimate breakthrough times of flow paths from the repository area, etc. Groundwater flows have been calculated by use of two mathematical (numerical) models: A very large groundwater flow model, much larger than the regional flow model used in the Laxemar site description version 1.2, and a smaller flow model that is of a comparable size to the regional model used in the site description. The models are identical except for the different horizontal extensions of the models; the large model extends to the west much further than the small model. The westernmost lateral boundary of the small model is a topographic water divide approx. 7 km from the central parts of the Laxemar investigation area, and the westernmost lateral boundary of the large model is a topographic water divide approx. 40 km from the central parts of the Laxemar investigation area. In the models the lateral boundaries are defined as no-flow boundaries. The objective of the study is to calculate and compare the groundwater flow properties at a tentative repository area at Laxemar; by use of a large flow model and a small flow model. The comparisons include the following three parameters: - Length of flow paths from the tentative repository area. - Advective breakthrough time for flow paths from the tentative repository area. - Magnitude of flow at the tentative repository area. The comparisons demonstrated the following considering the median values of the obtained distributions of flow paths

  13. Chemistry data from surface ecosystems in Forsmark and Laxemar-Simpevarp. Site specific data used for estimation of CR and Kd values in SR-Site

    International Nuclear Information System (INIS)

    Troejbom, Mats; Norden, Sara

    2010-11-01

    This report is a background report for the biosphere analysis of the SR-Site Safety Assessment. This work aims to compile information from the Forsmark and Laxemar-Simpevarp sites in order to select and provide relevant site data for parameter sed in the Radionuclide Dose Model. This report contains an overview of all available chemistry data from the surface ecosystems at Forsmark and Laxemar-Simpevarp areas, comprising hydrochemistry of shallow groundwater, porewater, lake water, stream water and sea water as well as the chemical composition of the regolith and biota of the terrestrial, limnic and marine ecosystems. Detailed references to data reports are tabulated and all sampling points are shown in a large number of maps in Chapter 2. An explorative analysis in Chapter 3 is the basis for the final selection of site data described in Chapter 4

  14. Final disposal Forsmark, Simpevarp and Laxemar. Inflow of ground water and influence on hydrogeologic and hydrologic conditions; Slutfoervar Forsmark, Simpevarp och Laxemar. Inlaeckage av grundvatten samt paaverkan paa hydrogeologiska och hydrologiska foerhaallanden

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent [Golder Associates AB, Stockholm (Sweden)

    2006-10-15

    This report summarizes the description of the natural (uninfluenced) hydrogeological and hydrological conditions at the possible final repository locations Forsmark, Simpevarp and Laxemar. For each site, the description is based on SKB's site descriptions version 1.2. The report provides assessments of the inflow and the effects on the surroundings (groundwater drawdown and the associated area of influence) due to construction, operation, and closing of a repository for spent nuclear fuel at the above locations. The assessment of the effects of the repository on its surroundings is primarily based on calculation results from two numerical flow models, DarcyTools and MOUSESHE (for Simpevarp, only DarcyTools has been used). The basis for the modelling is SKB's site descriptions version 1.2, which will be updated in the form of new versions. Moreover, the models are based on a preliminary layout of the repository at each location. Hence, the flow models will be developed further when the site descriptions are updated. The results may also be affected by changes of the repository layout. The modelling projects have been performed in the same order as they are presented in the report (Forsmark, Simpevarp and Laxemar). Some aspects of the numerical models, and the coupling between them, have been developed and improved during the course of work. Examples on major differences between the models include the technique to simulate grouting in DarcyTools, and the possibility to visualize modelling results from this model, for instance on other types of background maps. The results show a small inflow and a small area of influence for a repository at Forsmark. The upper parts of the repository (c 100 m depth and upwards) give the largest contribution to the inflow and the area of influence. This indicates that the effects on the surroundings from the deep and the near surface parts of the repository can be analysed separately. For a repository at Simpevarp and

  15. Final repository for spent nuclear fuel. Underground design Simpevarp, Layout D1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-04-15

    This report is a compilation of the results of the underground design work carried out in design phase D1 of the Repository Design Project within the Deep Repository Project for the Simpevarp site. Similar reports are also being produced for the Laxemar and Forsmark sites. The design phase coincides with the initial site investigation phase. The main purpose of phase D1 is to answer the question 'Can a final repository be accommodated within the designated site', but also to test the design methodology and provide feedback to the modelling project. Design was carried out in accordance with the methodology described in UDP (Underground Design Premises), SKB R-04-60, and was based on preliminary data from various disciplines in the site modelling project. The preliminary input data used were then cross-checked against data in the final Site Descriptive Model SDM v 1.2 and significant differences were integrated in the design work. The design results from each design topic were presented by the designer at presentation meetings for SKB's design management and the reviewers engaged by SKB for the specific topic. After the presentation meeting the designer wrote up the work reports for the topic in question. The work reports were then reviewed by SKB's review team. The results of the review were compiled in a statement that was submitted to the designer to be dealt with. In the statement the designer documented which comments were dealt with and how. This report is a compilation of the entire design phase D1 for Simpevarp. The 3D layout with coordinate lists for deposition holes and tunnels that was drawn to illustrate a possible layout was used in the Preliminary safety evaluation of the Simpevarp subarea and the hydro modelling of the Open Repository, both activities within the Deep Repository Project. According to current plans for the Swedish nuclear programme, the minimum required number of canister positions in the repository is estimated to be

  16. Validation of coastal oceanographic models at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Engqvist, Anders; Andrejev, Oleg

    2008-12-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and the Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The characterization work is divided into an initial site investigation phase and a complete site investigation phase. In this context, the water exchange of the coastal zone is one link of the chain of possible nuclide transport mechanisms that must be assessed in the site description of potential repository areas. For the purpose of validating the pair of nested 3D-models and the coupled discrete basin (CDB-) model employed to simulate the water exchange in the near-shore coastal zone in the Laxemar-Simpevarp area, an encompassing measurement program entailing data from six stations (of which two are close) has been performed. The design of this program was to first assess to what degree the forcing of the fine resolution (FR-) model of the Laxemar- Simpevarp study area at its interfacial boundary to the coarse resolution (CR-) model of the entire Baltic was reproduced. In addition to this, it is of particular interest how the time-varying density-determining properties, salinity and temperature, at the borders are propagated into the FR-domain and further influence the water exchange with the interior, more secluded, basins. An important part of the validation process has been to carefully evaluate which measurement data that can be considered reliable. The result was that some periods of foremost near-surface salinity data had to be discarded due to growth of algae on the conductivity sensors. Interference with ship traffic and lack of absolute calibration of the salinity meters necessitated dismissal of measurement data too. In this study so-called Mesan data have been consistently used for the meteorological forcing of the 3D-models. Relative the assessed data that can be accepted as adequate, the outcome of the

  17. Validation of coastal oceanographic models at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Engqvist, Anders (A och I Engqvist Konsult HB, Vaxholm (SE)); Andrejev, Oleg (Finnish Inst. of Marine Research, Helsinki (FI))

    2008-12-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterization at two different locations, the Forsmark and the Laxemar-Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. The characterization work is divided into an initial site investigation phase and a complete site investigation phase. In this context, the water exchange of the coastal zone is one link of the chain of possible nuclide transport mechanisms that must be assessed in the site description of potential repository areas. For the purpose of validating the pair of nested 3D-models and the coupled discrete basin (CDB-) model employed to simulate the water exchange in the near-shore coastal zone in the Laxemar-Simpevarp area, an encompassing measurement program entailing data from six stations (of which two are close) has been performed. The design of this program was to first assess to what degree the forcing of the fine resolution (FR-) model of the Laxemar- Simpevarp study area at its interfacial boundary to the coarse resolution (CR-) model of the entire Baltic was reproduced. In addition to this, it is of particular interest how the time-varying density-determining properties, salinity and temperature, at the borders are propagated into the FR-domain and further influence the water exchange with the interior, more secluded, basins. An important part of the validation process has been to carefully evaluate which measurement data that can be considered reliable. The result was that some periods of foremost near-surface salinity data had to be discarded due to growth of algae on the conductivity sensors. Interference with ship traffic and lack of absolute calibration of the salinity meters necessitated dismissal of measurement data too. In this study so-called Mesan data have been consistently used for the meteorological forcing of the 3D-models. Relative the assessed data that can be accepted as adequate, the outcome of the

  18. Description of regolith at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Sohlenius, Gustav; Hedenstroem, Anna

    2008-11-01

    This report compiles all known available information regarding the regolith in the Laxemar-Simpevarp regional model area. Regolith refers to the loose deposits overlying the bedrock. In the Laxemar-Simpevarp area, all known regolith was deposited during the Quaternary period and is consequently often referred to as Quaternary deposits (QD). In the terrestrial areas the uppermost part of the regolith, which has been affected by climate and vegetation, is referred to as soil. The geographical and stratigraphical distributions of the regolith have been used to construct a model showing the distribution of regolith depths in the whole model area. The stratigraphical units shown in the regolith depth and stratigraphy model have been characterised with respect to physical and chemical properties. Most of the data used for that characterisation have been obtained from the site investigation but some data were taken from the literature. All QD in the Laxemar area have most probably been deposited during or after the latest deglaciation. The ice sheet in the area moved from the north-west during the latest ice age. The Baltic Sea completely covered the investigated area after the latest deglaciation c 12,000 BC. Land uplift was fastest during the first few thousand years following the deglaciation and has subsequently decreased to the present value of 1 mm/year. Older QD have been eroded in areas exposed to waves and currents and the material has later been redeposited. Fine-grained sediments have been deposited on the floor of bays and in other sheltered positions. Peat has accumulated in many of the wetlands situated in topographically low positions. The groundwater table in many of the former wetlands has been artificially lowered to obtain land for forestry and agriculture, which has caused the peat to partly or completely oxidise. As land uplift proceeds, some new areas are being subjected to erosion at the same time as other new areas are becoming lakes and sheltered

  19. Description of regolith at Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Sohlenius, Gustav; Hedenstroem, Anna (Geological Survey of Sweden (SGU), Uppsala (Sweden))

    2008-11-15

    This report compiles all known available information regarding the regolith in the Laxemar-Simpevarp regional model area. Regolith refers to the loose deposits overlying the bedrock. In the Laxemar-Simpevarp area, all known regolith was deposited during the Quaternary period and is consequently often referred to as Quaternary deposits (QD). In the terrestrial areas the uppermost part of the regolith, which has been affected by climate and vegetation, is referred to as soil. The geographical and stratigraphical distributions of the regolith have been used to construct a model showing the distribution of regolith depths in the whole model area. The stratigraphical units shown in the regolith depth and stratigraphy model have been characterised with respect to physical and chemical properties. Most of the data used for that characterisation have been obtained from the site investigation but some data were taken from the literature. All QD in the Laxemar area have most probably been deposited during or after the latest deglaciation. The ice sheet in the area moved from the north-west during the latest ice age. The Baltic Sea completely covered the investigated area after the latest deglaciation c 12,000 BC. Land uplift was fastest during the first few thousand years following the deglaciation and has subsequently decreased to the present value of 1 mm/year. Older QD have been eroded in areas exposed to waves and currents and the material has later been redeposited. Fine-grained sediments have been deposited on the floor of bays and in other sheltered positions. Peat has accumulated in many of the wetlands situated in topographically low positions. The groundwater table in many of the former wetlands has been artificially lowered to obtain land for forestry and agriculture, which has caused the peat to partly or completely oxidise. As land uplift proceeds, some new areas are being subjected to erosion at the same time as other new areas are becoming lakes and sheltered

  20. Solid/liquid partition coefficients (Kd) for selected soils and sediments at Forsmark and Laxemar-Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Sheppard, Steve; Long, Jeff; Sanipelli, Barb [ECOMatters Inc., Pinawa (Canada); Sohlenius, Gustav [Geological Survey of Sweden (SGU), Uppsala (Sweden)

    2009-03-15

    Soil and sediment solid/liquid partition coefficients (Kd) are used to indicate the relative mobility of radionuclides and elements of concern from nuclear fuel waste, as well as from other sources. The Kd data are inherently extremely variable, but also vary systematically with key environmental attributes. For soil Kd, the key variables are pH, clay content and organic carbon content. For sediment Kd, water type (freshwater versus marine) and sediment type (benthic versus suspended) are important. This report summarized Kd data for soils and sediments computed from indigenous stable element concentrations measured at the Forsmark and Laxemar-Simpevarp sites. These were then compared to several literature sources of Kd data for Ce, Cl, Co, Cr, Cs, Fe, Ho, I, La, Mn, Mo, Nb, Nd, Ni, Np, Pa, Pb, Pu, Ra, Sb, Se, Sm, Sn, Sr, Tc, Th, Tm, U and Yb. The Kd data computed from indigenous stable element concentrations may be especially relevant for assessment of long-lived radionuclides from deep disposal of waste, because the long time frame for the potential releases is more consistent with the steady state measured using indigenous stable elements. For almost every one of these elements in soils, a statistically meaningful regression equation was developed to allow estimation of Kd for any soil given a modest amount of information about the soil. Nonetheless, the median residual geometric standard deviation (GSD) was 4.3-fold, implying confidence bounds of about 18-fold above and below the best estimate Kd. For sediment, the values are categorised simply by water type and sediment type. The median GSD for sediment Kd as measured at the Forsmark and Laxemar-Simpevarp sites was 2.5-fold, but the median GSD among literature values was as high as 8.6-fold. Clearly, there remains considerable uncertainty in Kd values, and it is important to account for this in assessment applications

  1. Solid/liquid partition coefficients (Kd) for selected soils and sediments at Forsmark and Laxemar-Simpevarp

    International Nuclear Information System (INIS)

    Sheppard, Steve; Long, Jeff; Sanipelli, Barb; Sohlenius, Gustav

    2009-03-01

    Soil and sediment solid/liquid partition coefficients (Kd) are used to indicate the relative mobility of radionuclides and elements of concern from nuclear fuel waste, as well as from other sources. The Kd data are inherently extremely variable, but also vary systematically with key environmental attributes. For soil Kd, the key variables are pH, clay content and organic carbon content. For sediment Kd, water type (freshwater versus marine) and sediment type (benthic versus suspended) are important. This report summarized Kd data for soils and sediments computed from indigenous stable element concentrations measured at the Forsmark and Laxemar-Simpevarp sites. These were then compared to several literature sources of Kd data for Ce, Cl, Co, Cr, Cs, Fe, Ho, I, La, Mn, Mo, Nb, Nd, Ni, Np, Pa, Pb, Pu, Ra, Sb, Se, Sm, Sn, Sr, Tc, Th, Tm, U and Yb. The Kd data computed from indigenous stable element concentrations may be especially relevant for assessment of long-lived radionuclides from deep disposal of waste, because the long time frame for the potential releases is more consistent with the steady state measured using indigenous stable elements. For almost every one of these elements in soils, a statistically meaningful regression equation was developed to allow estimation of Kd for any soil given a modest amount of information about the soil. Nonetheless, the median residual geometric standard deviation (GSD) was 4.3-fold, implying confidence bounds of about 18-fold above and below the best estimate Kd. For sediment, the values are categorised simply by water type and sediment type. The median GSD for sediment Kd as measured at the Forsmark and Laxemar-Simpevarp sites was 2.5-fold, but the median GSD among literature values was as high as 8.6-fold. Clearly, there remains considerable uncertainty in Kd values, and it is important to account for this in assessment applications

  2. Chemistry data from surface ecosystems in Forsmark and Laxemar-Simpevarp. Site specific data used for estimation of CR and K{sub d} values in SR-Site

    Energy Technology Data Exchange (ETDEWEB)

    Troejbom, Mats [Mats Troejbom Konsult AB (Sweden); Norden, Sara [Svensk Kaernbraenslehantering AB (Sweden)

    2010-11-15

    This report is a background report for the biosphere analysis of the SR-Site Safety Assessment. This work aims to compile information from the Forsmark and Laxemar-Simpevarp sites in order to select and provide relevant site data for parameter sed in the Radionuclide Dose Model. This report contains an overview of all available chemistry data from the surface ecosystems at Forsmark and Laxemar-Simpevarp areas, comprising hydrochemistry of shallow groundwater, porewater, lake water, stream water and sea water as well as the chemical composition of the regolith and biota of the terrestrial, limnic and marine ecosystems. Detailed references to data reports are tabulated and all sampling points are shown in a large number of maps in Chapter 2. An explorative analysis in Chapter 3 is the basis for the final selection of site data described in Chapter 4

  3. Alternative DFN model based on initial site investigations at Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Darcel, C. [Itasca Consultants, Ecully (France); Davy, S.A.P.; Bour, O.; Dreuzy, J.R. de [Geosciences, Rennes (France)

    2004-12-01

    In this report, we provide a first-order analysis of the fracture network at the Simpevarp site. The first order model is the fracture distribution function, noted, fdf, which provides the number of fractures having a given orientation and length, and belonging to a given volume of observation. The first-order distribution model does not describe higher-order correlation between fracture parameters, such as a possible dependency of fracture length distribution with orientations. We also check that most of the information is contained in this 1st-order distribution model, and that dividing the fracture networks into different sets do not bring a better statistical description. The fracture distribution function contains 3 main distributions: the probability distribution of fracture orientations, the dependency on the size of the sampling domain that may exhibit non-trivial scaling in case of fractal correlations, and the fracture-length density distribution, which appears to be well fitted by a power law. The main scaling parameters are the fractal dimension and the power-law exponent of the fracture length distribution. The former was found to be about equal to the embedding dimension, meaning that fractal correlations are weak and can be neglected in the DFN model. The latter depends on geology, that is either lithology or grain size, with values that ranges from 3.2 for granite-like outcrops to 4 for diorite or monzodiorite outcrops, as well as for the large-scale lineament maps. When analyzing the consistency of the different datasets (boreholes, outcrops, lineament maps), we found that two different DFNs can be described: the first one is derived from the fdf of the outcrop with fine-grained size lithology, and is valid across all scales investigated in this study, from the highly-fractured cores to large-scale maps; the second one is derived from the fdf of the outcrops with coarse-grained size lithology, and is found consistent with cores that present the

  4. Large-area and highly crystalline MoSe2 for optical modulator

    Science.gov (United States)

    Yin, Jinde; Chen, Hao; Lu, Wei; Liu, Mengli; Li, Irene Ling; Zhang, Min; Zhang, Wenfei; Wang, Jinzhang; Xu, Zihan; Yan, Peiguang; Liu, Wenjun; Ruan, Shuangchen

    2017-12-01

    Transition metal dichalcogenides (TMDs) have been successfully used as broadband optical modulator materials for pulsed fiber laser systems. However, the nonlinear optical absorptions of exfoliated TMDs are strongly limited by their nanoflakes morphology with uncontrollable lateral size and thickness. In this work, we provide an effective method to fully explore the nonlinear optical properties of MoSe2. Large-area and high quality lattice MoSe2 grown by chemical vapor deposition method was adopted as an optical modulator for the first time. The large-area MoSe2 shows excellent nonlinear optical absorption with a large modulation depth of 21.7% and small saturable intensity of 9.4 MW cm-2. After incorporating the MoSe2 optical modulator into fiber laser cavity as a saturable absorber, a highly stable Q-switching operation with single pulse energy of 224 nJ is achieved. The large-area MoSe2 possessing superior nonlinear optical properties compared to exfoliated nanoflakes affords possibility for the larger-area two-dimensional materials family as high performance optical devices.

  5. Preliminary safety evaluation for the Simpevarp subarea. Based on data and site descriptions after the initial site investigation stage

    International Nuclear Information System (INIS)

    2005-04-01

    The main objectives of this Preliminary safety evaluation (PSE) of the Simpevarp subarea are: to determine, whether the feasibility study's judgement of the suitability of the candidate area with respect to long-term safety holds up in the light of the site investigation data; to provide feedback to continued site investigations and site-specific repository design and to identify site specific scenarios and geoscientific issues for further analyses. The PSE focuses on comparing the attained knowledge of the sites with the suitability criteria as set out by SKB in the report SKB-TR--00-12. These criteria both concern properties of the site judged to be necessary for safety and engineering (requirements) and properties judged to be beneficial (preferences). The findings are then evaluated in order to provide feedback to continued investigations and design work. The PSE does not aim at comparing sites and does not assess compliance with safety and radiation protection criteria. The evaluation shows that even considering remaining uncertainties, the Simpevarp subarea meets all safety requirements and most of the safety preferences. Consequently, from a safety point of view, there is no reason not to continue the Site Investigations of the Simpevarp subarea. There are still uncertainties to resolve and the safety would eventually need to be verified through a full safety assessment. Still, this Preliminary Safety Evaluation demonstrates that it is likely that a safe repository for spent nuclear fuel of the KBS-3 type could be constructed at the site. The following feedback is provided to the site investigations and the associated site modelling: Reducing the uncertainty on the deformation zone geometry within the Simpevarp subarea would allow for a more specified layout, although the sensitivity analysis shows that the space needed is rather robust with respect to uncertainties in the zones. There is substantial uncertainty in the discrete fracture network (DFN) model

  6. Molecular beam epitaxy of large-area SnSe2 with monolayer thickness fluctuation

    Science.gov (United States)

    Park, Young Woon; Jerng, Sahng-Kyoon; Jeon, Jae Ho; Roy, Sanjib Baran; Akbar, Kamran; Kim, Jeong; Sim, Yumin; Seong, Maeng-Je; Kim, Jung Hwa; Lee, Zonghoon; Kim, Minju; Yi, Yeonjin; Kim, Jinwoo; Noh, Do Young; Chun, Seung-Hyun

    2017-03-01

    The interest in layered materials is largely based on the expectation that they will be beneficial for a variety of applications, from low-power-consuming, wearable electronics to energy harvesting. However, the properties of layered materials are highly dependent on thickness, and the difficulty of controlling thickness over a large area has been a bottleneck for commercial applications. Here, we report layer-by-layer growth of SnSe2, a layered semiconducting material, via van der Waals epitaxy. The films were fabricated on insulating mica substrates with substrate temperatures in the range of 210 °C-370 °C. The surface consists of a mixture of N and (N ± 1) layers, showing that the thickness of the film can be defined with monolayer accuracy (±0.6 nm). High-resolution transmission electron microscopy reveals a polycrystalline film with a grain size of ˜100 nm and clear Moiré patterns from overlapped grains with similar thickness. We also report field effect mobility values of 3.7 cm2 V-1 s-1 and 6.7 cm2 V-1 s-1 for 11 and 22 nm thick SnSe2, respectively. SnSe2 films with customizable thickness can provide valuable platforms for industry and academic researchers to fully exploit the potential of layered materials.

  7. Numerical modelling of present and future hydrology at Laxemar- Simpevarp

    International Nuclear Information System (INIS)

    Sassner, Mona; Sabel, Ulrika; Bosson, Emma; Berglund, Sten

    2011-04-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has performed site investigations at two potential sites for a final repository for spent nuclear fuel. This report presents results of water flow modelling of the Laxemar area. The modelling reported in this document is focused on the near-surface groundwater, i.e. groundwater in Quaternary deposits and shallow rock, and surface water systems, and was performed using the MIKE SHE tool. The main objective of the modelling was to provide input to the radionuclide transport and dose calculations that were carried out as a part of the comparison between the Laxemar and Forsmark sites

  8. Numerical modelling of present and future hydrology at Laxemar- Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Sassner, Mona; Sabel, Ulrika (DHI Sverige AB (Sweden)); Bosson, Emma; Berglund, Sten (Svensk Kaernbraenslehantering AB (Sweden))

    2011-04-15

    The Swedish Nuclear Fuel and Waste Management Company (SKB) has performed site investigations at two potential sites for a final repository for spent nuclear fuel. This report presents results of water flow modelling of the Laxemar area. The modelling reported in this document is focused on the near-surface groundwater, i.e. groundwater in Quaternary deposits and shallow rock, and surface water systems, and was performed using the MIKE SHE tool. The main objective of the modelling was to provide input to the radionuclide transport and dose calculations that were carried out as a part of the comparison between the Laxemar and Forsmark sites

  9. Large-area snow-like MoSe2 monolayers: synthesis, growth mechanism, and efficient electrocatalyst application.

    Science.gov (United States)

    Huang, Jingwen; Liu, Huiqiang; Jin, Bo; Liu, Min; Zhang, Qingchun; Luo, Liqiong; Chu, Shijin; Chu, Sheng; Peng, Rufang

    2017-07-07

    This study explores the large-area synthesis of controllable morphology, uniform, and high-quality monolayer. MoSe 2 is essential for its potential application in optoelectronics, photocatalysis, and renewable energy sources. In this study, we successfully synthesized snow-like MoSe 2 monolayers using a simple chemical vapor deposition method. Results reveal that snow-like MoSe 2 is a single crystal with a hexagonal structure, a thickness of ∼0.9 nm, and a lateral dimension of up to 20 μm. The peak position of the photoluminescence spectra is ∼1.52 eV corresponding to MoSe 2 monolayer. The growth mechanism of the snow-like MoSe 2 monolayer was investigated and comprised a four-step process during growth. Finally, we demonstrate that the snow-like MoSe 2 monolayers are ideal electrocatalysts for hydrogen evolution reactions (HERs), reflected by a low Tafel slope of ∼68 mV/decade. Compared with the triangular-shaped MoSe 2 monolayer, the hexangular snow-like shape with plentiful edges is superior for perfect electrocatalysts for HERs or transmission devices of optoelectronic signals.

  10. Thermal modelling. Preliminary site description Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Jan; Back, Paer-Erik; Bengtsson, Anna; Laendell, Maerta [Geo Innova AB, Linkoeping (Sweden)

    2005-08-15

    This report presents the thermal site descriptive model for the Simpevarp subarea, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at possible canister scale has been modelled for four different lithological domains (RSMA01 (Aevroe granite), RSMB01 (Fine-grained dioritoid), RSMC01 (mixture of Aevroe granite and Quartz monzodiorite), and RSMD01 (Quartz monzodiorite)). A main modelling approach has been used to determine the mean value of the thermal conductivity. Three alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological model for the Simpevarp subarea, version 1.2 together with rock type models constituted from measured and calculated (from mineral composition) thermal conductivities. For one rock type, the Aevroe granite (501044), density loggings within the specific rock type has also been used in the domain modelling in order to consider the spatial variability within the Aevroe granite. This has been possible due to the presented relationship between density and thermal conductivity, valid for the Aevroe granite. Results indicate that the mean of thermal conductivity is expected to exhibit only a small variation between the different domains, from 2.62 W/(m.K) to 2.80 W/(m.K). The standard deviation varies according to the scale considered and for the canister scale it is expected to range from 0.20 to 0.28 W/(m.K). Consequently, the lower confidence limit (95% confidence) for the canister scale is within the range 2.04-2.35 W/(m.K) for the different domains. The temperature dependence is rather small with a decrease in thermal conductivity of 1.1-3.4% per 100 deg C increase in temperature for the dominating rock

  11. Thermal modelling. Preliminary site description Simpevarp subarea - version 1.2

    International Nuclear Information System (INIS)

    Sundberg, Jan; Back, Paer-Erik; Bengtsson, Anna; Laendell, Maerta

    2005-08-01

    This report presents the thermal site descriptive model for the Simpevarp subarea, version 1.2. The main objective of this report is to present the thermal modelling work where data has been identified, quality controlled, evaluated and summarised in order to make an upscaling to lithological domain level possible. The thermal conductivity at possible canister scale has been modelled for four different lithological domains (RSMA01 (Aevroe granite), RSMB01 (Fine-grained dioritoid), RSMC01 (mixture of Aevroe granite and Quartz monzodiorite), and RSMD01 (Quartz monzodiorite)). A main modelling approach has been used to determine the mean value of the thermal conductivity. Three alternative/complementary approaches have been used to evaluate the spatial variability of the thermal conductivity at domain level. The thermal modelling approaches are based on the lithological model for the Simpevarp subarea, version 1.2 together with rock type models constituted from measured and calculated (from mineral composition) thermal conductivities. For one rock type, the Aevroe granite (501044), density loggings within the specific rock type has also been used in the domain modelling in order to consider the spatial variability within the Aevroe granite. This has been possible due to the presented relationship between density and thermal conductivity, valid for the Aevroe granite. Results indicate that the mean of thermal conductivity is expected to exhibit only a small variation between the different domains, from 2.62 W/(m.K) to 2.80 W/(m.K). The standard deviation varies according to the scale considered and for the canister scale it is expected to range from 0.20 to 0.28 W/(m.K). Consequently, the lower confidence limit (95% confidence) for the canister scale is within the range 2.04-2.35 W/(m.K) for the different domains. The temperature dependence is rather small with a decrease in thermal conductivity of 1.1-3.4% per 100 deg C increase in temperature for the dominating rock

  12. Heavy metal pollution in soils of abandoned mining areas (SE, Spain)

    Science.gov (United States)

    Martínez-Sánchez, M. J.; Pérez-Sirvent, C.; Molina, J.; Tudela, M. L.; Navarro, M. C.; García-Lorenzo, M. L.

    2009-04-01

    Elevated levels of heavy metals can be found in and around disused metalliferous mines due to discharge and dispersion of mine wastes into nearby agricultural soils, food crops and stream systems. Heavy metals contained in the residues from mining and metallurgical operations are often dispersed by wind and/or water after their disposal. These areas have severe erosion problems caused by wind and water runoff in which soil and mine spoil texture, landscape topography and regional and microclimate play an important role. The present study was carried out in the Cabezo Rajao (La Uni

  13. Environmental risks associated to wind erosion in a metal mining area from SE Spain

    International Nuclear Information System (INIS)

    Garcia Fernandez, G.; Romero Diaz, A.

    2009-01-01

    Soils and mining wastes from the Mediterranean mining area placed in the Sierra Minera Mountains are highly enriched in heavy metals such as lead and zinc, but also other metals such as cadmium and arsenic. Wind erosion in this area could be considered extremely high and hazards associated to this eroded sediments seems to be high because the huge amount of metals present in this wastes. Therefore, combination of high erosion rates and high metal concentration in this mining waste, make those environmental risks can be considered high for the surrounding ecosystems, but also for public health of the nearby villages and towns. In order, to study these wind erosion processes over these mining materials, some experiments for the evaluation of the transportation of soil particles were carried out. Erosion rates in this realm is particularly important during spring months, when increased activity of the eastern winds brings intense soil dragging, with strong effects on the metals dispersion, including the massive removal of sediments. (Author) 16 refs.

  14. Environmental risks associated to wind erosion in a metal mining area from SE Spain

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Fernandez, G.; Romero Diaz, A.

    2009-07-01

    Soils and mining wastes from the Mediterranean mining area placed in the Sierra Minera Mountains are highly enriched in heavy metals such as lead and zinc, but also other metals such as cadmium and arsenic. Wind erosion in this area could be considered extremely high and hazards associated to this eroded sediments seems to be high because the huge amount of metals present in this wastes. Therefore, combination of high erosion rates and high metal concentration in this mining waste, make those environmental risks can be considered high for the surrounding ecosystems, but also for public health of the nearby villages and towns. In order, to study these wind erosion processes over these mining materials, some experiments for the evaluation of the transportation of soil particles were carried out. Erosion rates in this realm is particularly important during spring months, when increased activity of the eastern winds brings intense soil dragging, with strong effects on the metals dispersion, including the massive removal of sediments. (Author) 16 refs.

  15. Identification of the origin of salts in an agricultural area of SE Spain

    Science.gov (United States)

    Acosta, Jose A.; Faz, Angel; Kalbitz, Karsten; Jansen, Boris; Silvia, Martinez-Martinez

    2010-05-01

    In spite of soil salinity having been widely studied in many part of the world, origin of salinity has not been addresses in detail in some of the most productive agricultural areas of Europe (e.g. southeast of Spain). According to the European Commission, salinization affects about 1 to 3 million ha of the area of the European Union and Candidate Countries. In Europe, most of the salt-affected land surfaces are concentrated in the Mediterranean basin. In Spain, about 3% of the 3.5 million hectares of irrigated land are severely affected by salts and another 15% is at serious risk of imminent salinization. Due to the limited water resources in southeast of Spain, water with marginal quality is used for irrigation. The use of this water has led to degradation, reduction of the land's production capacity and soil salinization. The main aim of the present study was to identify the origin of the salts involved in such salinization, using classical and multivariable statistical techniques. In order to achieve this objective, surface soil samples were collected in January and July 2009 at 48 sites located in a representative lemon production area close to City of Murcia, covering a surface area of 44 km2. Soil pH, electrical conductivity, ionic composition, total organic matter, equivalent calcium carbonate, cation exchange capacity and particle size distribution were determined. The Pearson correlation coefficient, r, was used to measure the relationship between two quantitative variables and principal components analysis was used to study the correlations among anions and cations and their grouping into several factors. Results indicated that the high electrical conductivity found in the study area indeed comes from poor quality irrigation water used for agriculture. Anions and cations responsible of the salinity were chlorides, sulphates, calcium, magnesium and sodium. Mismanagement of water and traditional irrigation system resulted in salt build-up in the soil

  16. Regional groundwater flow model for a glaciation scenario. Simpevarp subarea - version 1.2

    International Nuclear Information System (INIS)

    Jaquet, O.; Siegel, P.

    2006-10-01

    A groundwater flow model (glaciation model) was developed at a regional scale in order to study long term transient effects related to a glaciation scenario likely to occur in response to climatic changes. Conceptually the glaciation model was based on the regional model of Simpevarp and was then extended to a mega-regional scale (of several hundred kilometres) in order to account for the effects of the ice sheet. These effects were modelled using transient boundary conditions provided by a dynamic ice sheet model describing the phases of glacial build-up, glacial completeness and glacial retreat needed for the glaciation scenario. The results demonstrate the strong impact of the ice sheet on the flow field, in particular during the phases of the build-up and the retreat of the ice sheet. These phases last for several thousand years and may cause large amounts of melt water to reach the level of the repository and below. The highest fluxes of melt water are located in the vicinity of the ice margin. As the ice sheet approaches the repository location, the advective effects gain dominance over diffusive effects in the flow field. In particular, up-coning effects are likely to occur at the margin of the ice sheet leading to potential increases in salinity at repository level. For the base case, the entire salinity field of the model is almost completely flushed out at the end of the glaciation period. The flow patterns are strongly governed by the location of the conductive features in the subglacial layer. The influence of these glacial features is essential for the salinity distribution as is their impact on the flow trajectories and, therefore, on the resulting performance measures. Travel times and F-factor were calculated using the method of particle tracking. Glacial effects cause major consequences on the results. In particular, average travel times from the repository to the surface are below 10 a during phases of glacial build-up and retreat. In comparison

  17. Regional groundwater flow model for a glaciation scenario. Simpevarp subarea - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Jaquet, O.; Siegel, P. [Colenco Power Engineering Ltd, Baden-Daettwil (Switzerland)

    2006-10-15

    A groundwater flow model (glaciation model) was developed at a regional scale in order to study long term transient effects related to a glaciation scenario likely to occur in response to climatic changes. Conceptually the glaciation model was based on the regional model of Simpevarp and was then extended to a mega-regional scale (of several hundred kilometres) in order to account for the effects of the ice sheet. These effects were modelled using transient boundary conditions provided by a dynamic ice sheet model describing the phases of glacial build-up, glacial completeness and glacial retreat needed for the glaciation scenario. The results demonstrate the strong impact of the ice sheet on the flow field, in particular during the phases of the build-up and the retreat of the ice sheet. These phases last for several thousand years and may cause large amounts of melt water to reach the level of the repository and below. The highest fluxes of melt water are located in the vicinity of the ice margin. As the ice sheet approaches the repository location, the advective effects gain dominance over diffusive effects in the flow field. In particular, up-coning effects are likely to occur at the margin of the ice sheet leading to potential increases in salinity at repository level. For the base case, the entire salinity field of the model is almost completely flushed out at the end of the glaciation period. The flow patterns are strongly governed by the location of the conductive features in the subglacial layer. The influence of these glacial features is essential for the salinity distribution as is their impact on the flow trajectories and, therefore, on the resulting performance measures. Travel times and F-factor were calculated using the method of particle tracking. Glacial effects cause major consequences on the results. In particular, average travel times from the repository to the surface are below 10 a during phases of glacial build-up and retreat. In comparison

  18. Preliminary assessment of potential underground stability (wedge and spalling) at Forsmark, Simpevarp and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Derek [Univ. of Alberta, Edmonton (Canada). Geotechnical Engineering

    2005-12-15

    In SKB's Underground Design Premises the objective in the early design phase is to estimate if there is sufficient space for the repository at a site. One of the conditions that could limit the space available is stability of the underground openings, i.e., deposition tunnels and deposition boreholes. The purpose of this report is to provide a preliminary assessment of the potential for wedge instability and spalling that may be encountered at the Forsmark, Simpevarp and Laxemar sites based on information from the site investigations program up to July 30, 2004. The rock mass spalling strength was defined using the in-situ results from SKB's Aespoe Pillar Stability Experiment and AECL's Mine-by Experiment. These experiments suggest that the rock mass spalling strength for crystalline rocks can be estimated as 0.57 of the mean laboratory uniaxial compressive strength. A probability-based methodology utilizing this in-situ rock mass spalling strength has been developed for assessing the risk for spalling in a repository at the Forsmark, Simpevarp and Laxemar sites. The in-situ stresses and the uniaxial compressive strength data from these sites were used as the bases for the analyses. Preliminary findings from all sites suggest that, generally, the risk for spalling increases as the depth of the repository increases, simply because the stress magnitudes increase with depth. The depth at which the risk for spalling is significant, depends on the individual sites which are discussed below. The greatest uncertainty in the spalling analyses for Forsmark is related to the uncertainty in the horizontal stress magnitudes and associated stress gradients with depth. The confidence in these analyses can only be increased by increasing the confidence in the stress and geology model for the site. From the analyses completed it appears that spalling in the deposition tunnels can be controlled by orienting the tunnels approximately parallel to the maximum horizontal

  19. The hidden Mediterranean diet: wild vegetables traditionally gathered and consumed in the Gargano area, Apulia, SE Italy

    Directory of Open Access Journals (Sweden)

    Nello Biscotti

    2015-10-01

    Full Text Available Despite the extensive bio-scientific literature concerning the Mediterranean diet, which emerged in the last three decades, systematic ethnography-centered investigations on a crucial portion of this food system, linked to the traditional consumption of non-cultivated vegetables, are still largely lacking in many areas of the Mediterranean Basin. In this research, an ethnobotanical field study focusing on wild vegetables traditionally gathered and consumed locally, was conducted in a few centers and villages located in the Gargano area, northern Apulia, SE Italy, by interviewing twenty-five elderly informants. The folk culinary uses of seventy-nine botanical taxa of wild vascular plants, belonging to nineteen families, were recorded, thus showing a remarkable resilience of traditional environmental knowledge (TEK related to wild food plants. In particular, approximately one-fourth of the recorded wild vegetables are still very commonly gathered and consumed nowadays, while ten taxa have never been reported in previous ethnobotanical studies conducted in Southern Italy. These findings demonstrate the crucial cultural role played by folk cuisines in preserving TEK, despite significant socio-economic changes that have affected the study area during the past four decades.

  20. Seismic microzonation and velocity models of El Ejido area (SE Spain) from the diffuse-field H/V method

    Science.gov (United States)

    García-Jerez, Antonio; Seivane, Helena; Navarro, Manuel; Piña-Flores, José; Luzón, Francisco; Vidal, Francisco; Posadas, Antonio M.; Aranda, Carolina

    2016-04-01

    El Ejido town is located in the Campo de Dalías coastal plain (Almería province, SE Spain), emplaced in one of the most seismically active regions of Spain. The municipality has 84000 inhabitants and presented a high growth rate during the last twenty years. The most recent intense seismic activity occurred close to this town was in 1993 and 1994, with events of Mb = 4.9 and Mb = 5.0, respectively. To provide a basis for site-specific hazard analysis, we first carried out a seismic microzonation of this town in terms of predominant periods and geotechnical properties. The predominant periods map was obtained from ambient noise observations on a grid of 250 x 250 m in the main urban area, and sparser measurements on the outskirts. These broad-band records, of about 20 minutes long each, were analyzed by using the horizontal-to-vertical spectral ratio technique (H/V). Dispersion curves obtained from two array measurements of ambient noise and borehole data provided additional geophysical information. All the surveyed points in the town were found to have relatively long predominant periods ranging from 0.8 to 2.3 s and growing towards the SE. Secondary high-frequency (> 2Hz) peaks were found at about the 10% of the points only. On the other hand, Vs30 values of 550 - 650 m/s were estimated from the array records, corresponding to cemented sediments and medium-hard rocks. The local S-wave velocity structure has been inverted from the H/V curves for a subset of the measurement sites. We used an innovative full-wavefield method based on the diffuse-wavefield approximation (Sánchez-Sesma et al., 2011) combined with the simulated annealing algorithm. Shallow seismic velocities and deep boreholes data were used as constraints. The results show that the low-frequency resonances are related with the impedance contrast between several hundred meters of medium-hard sedimentary rocks (marls and calcarenites) with the stiffer basement of the basin, which dips to the SE. These

  1. Highly Sensitive Electromechanical Piezoresistive Pressure Sensors Based on Large-Area Layered PtSe2 Films.

    Science.gov (United States)

    Wagner, Stefan; Yim, Chanyoung; McEvoy, Niall; Kataria, Satender; Yokaribas, Volkan; Kuc, Agnieszka; Pindl, Stephan; Fritzen, Claus-Peter; Heine, Thomas; Duesberg, Georg S; Lemme, Max C

    2018-05-23

    Two-dimensional (2D) layered materials are ideal for micro- and nanoelectromechanical systems (MEMS/NEMS) due to their ultimate thinness. Platinum diselenide (PtSe 2 ), an exciting and unexplored 2D transition metal dichalcogenide material, is particularly interesting because its low temperature growth process is scalable and compatible with silicon technology. Here, we report the potential of thin PtSe 2 films as electromechanical piezoresistive sensors. All experiments have been conducted with semimetallic PtSe 2 films grown by thermally assisted conversion of platinum at a complementary metal-oxide-semiconductor (CMOS)-compatible temperature of 400 °C. We report high negative gauge factors of up to -85 obtained experimentally from PtSe 2 strain gauges in a bending cantilever beam setup. Integrated NEMS piezoresistive pressure sensors with freestanding PMMA/PtSe 2 membranes confirm the negative gauge factor and exhibit very high sensitivity, outperforming previously reported values by orders of magnitude. We employ density functional theory calculations to understand the origin of the measured negative gauge factor. Our results suggest PtSe 2 as a very promising candidate for future NEMS applications, including integration into CMOS production lines.

  2. CVD synthesis of large-area, highly crystalline MoSe2 atomic layers on diverse substrates and application to photodetectors.

    Science.gov (United States)

    Xia, Jing; Huang, Xing; Liu, Ling-Zhi; Wang, Meng; Wang, Lei; Huang, Ben; Zhu, Dan-Dan; Li, Jun-Jie; Gu, Chang-Zhi; Meng, Xiang-Min

    2014-08-07

    Synthesis of large-area, atomically thin transition metal dichalcogenides (TMDs) on diverse substrates is of central importance for the large-scale fabrication of flexible devices and heterojunction-based devices. In this work, we successfully synthesized a large area of highly-crystalline MoSe2 atomic layers on SiO2/Si, mica and Si substrates using a simple chemical vapour deposition (CVD) method at atmospheric pressure. Atomic force microscopy (AFM) and Raman spectroscopy reveal that the as-grown ultrathin MoSe2 layers change from a single layer to a few layers. Photoluminescence (PL) spectroscopy demonstrates that while the multi-layer MoSe2 shows weak emission peaks, the monolayer has a much stronger emission peak at ∼ 1.56 eV, indicating the transition from an indirect to a direct bandgap. Transmission electron microscopy (TEM) analysis confirms the single-crystallinity of MoSe2 layers with a hexagonal structure. In addition, the photoresponse performance of photodetectors based on MoSe2 monolayer was studied for the first time. The devices exhibit a rapid response of ∼ 60 ms and a good photoresponsivity of ∼ 13 mA/W (using a 532 nm laser at an intensity of 1 mW mm(-2) and a bias of 10 V), suggesting that MoSe2 monolayer is a promising material for photodetection applications.

  3. Petrology of blueschist and meta-greywacke along the Turkmeni-Ordib fault (Turkmeni area, SE of Anarak

    Directory of Open Access Journals (Sweden)

    Fereshteh Bayat

    2015-10-01

    Full Text Available Introduction The occurrence of blueschist metamorphic facies is believed to mark the existence of former subduction zones. This facies is represented in the main constituents of subduction-accretion complexes, where it occurs in separate tectonic sheets, imbricated slices, lenses, or exotic blocks within a serpentinite mélange (Volkova et al., 2011. The evidence of the presence and maturity of Paleo- Tethys oceanic crust in the CEIM (define this in Paleo-Tethys branches, subduction and collision has been studied by various authors (Bagheri, 2007; Zanchi et al., 2009; Bayat and Torabi, 2011; Torabi 2011. Late Paleozoic blueschists have recognized in the western part of the CEIM (e. g. Anarak, Chupanan and Turkmeni in linear trends. Metamorphic rocks of the Turkmeni area (SE of Anarak are composed of blueschist and meta-greywacke and are situated along the Turkmeni-Ordib fault associated with Paleozoic rock units and serpentinized peridotite bodies. Turkmeni blueschist and meta-greywackes have not been studied by previous workers. The Turkmeni blueschists consist of albite, winchite, actinolite and epidote. Granoblastic, nematoblastic and lepidoblastic are main textures in these rocks. Winchite is found in the matrix and around epidote grains. This sodic-calcic amphibole serves as an index mineral in blueschist facies. Actinolite and epidote formed during retrograde metamorphism of blueschists in the greenschist facies. The mineral assemblage of albite, epidote, chlorite and phengite ± garnet is present in meta-greywackes in the Turkmeni blueschists. Veins of garnet, muscovite, quartz and opaque minerals are extensive in these rocks. Epidote and chlorite formed in meta-greywackes by retrograde metamorphism in the greenschist facies. The aim of the present study is to determine the petrological and geochemical characteristics, P-T condition of blueschists and meta-greywackes, as well as the geotectonic setting of primary basaltic rocks of the

  4. Composition of the Rex Chert and associated rocks of the Permian Phosphoria Formation: Soda Springs area, SE Idaho

    Science.gov (United States)

    Hein, James R.; McIntyre, Brandie; Perkins, Robert B.; Piper, David Z.; Evans, James

    2002-01-01

    This study, one in a series, reports bulk chemical and mineralogical compositions, as well as petrographic and outcrop descriptions of rocks collected from three measured outcrop sections of the Rex Chert member of the Phosphoria Formation in SE Idaho. The three measured sections were chosen from ten outcrops of Rex Chert that were described in the field. The Rex Chert overlies the Meade Peak Phosphatic Shale Member of the Phosphoria Formation, the source of phosphate ore in the region. Rex Chert removed as overburden comprises part of the material disposed in waste-rock piles during phosphate mining. It has been proposed that the chert be used to cap and isolate waste piles, thereby inhibiting the leaching of potentially toxic elements into the environment. It is also used to surface roads in the mining district. The rock samples studied here constitute a set of individual chert beds that are representative of each stratigraphic section sampled. The informally named cherty shale member that overlies the Rex Chert in measured section 1 was also described and sampled. The upper Meade Peak and the transition zone to the Rex Chert were described and sampled in section 7. The cherts are predominantly spicularite composed of granular and mosaic quartz, and sponge spicules, with various but minor amounts of other fossils and detrital grains. The cherty shale member and transition rocks between the Meade Peak and Rex Chert are siliceous siltstones and argillaceous cherts with ghosts of sponge spicules and somewhat more detrital grains than the chert. The overwhelmingly dominant mineral is quartz, although carbonate beds are rare in each section and are composed predominantly of calcite and dolomite in addition to quartz. Feldspar, mica, clay minerals, calcite, dolomite, and carbonate fluorapatite are minor to trace minerals in the chert. The mean concentrations of oxides and elements in the Rex Chert and the cherty shale member are dominated by SiO2, which averages 94

  5. The hidden Mediterranean diet: wild vegetables traditionally gathered and consumed in the Gargano area, Apulia, SE Italy

    OpenAIRE

    Nello Biscotti; Andrea Pieroni

    2015-01-01

    Despite the extensive bio-scientific literature concerning the Mediterranean diet, which emerged in the last three decades, systematic ethnography-centered investigations on a crucial portion of this food system, linked to the traditional consumption of non-cultivated vegetables, are still largely lacking in many areas of the Mediterranean Basin. In this research, an ethnobotanical field study focusing on wild vegetables traditionally gathered and consumed locally, was conducted ...

  6. Suprabenthic assemblages from the Capbreton area (SE Bay of Biscay). Faunal recovery after a canyon turbidity disturbance

    Science.gov (United States)

    Frutos, Inmaculada; Sorbe, Jean Claude

    2017-12-01

    In the Capbreton area, suprabenthic assemblages were sampled with a sledge towed over the bottom, at different sites located within the upper part of a 'gouf-type' canyon (8 hauls between 642 m and 797 m, on the axis of the thalweg or on flat perched flank terraces such as site K), on the northern adjacent open slope (2 hauls between 500 and 567 m) and on the northern adjacent shelf margin (2 hauls between 151 m and 158 m). A multivariate analysis carried on the faunal data discriminated different assemblages in this area: a near-canyon shelf assemblage (55 species, mainly amphipods and decapods; 3496 ind./100 m2, 40% mysids; dominant species: Nyctiphanes couchii, Leptomysis gracilis, Weswoodilla rectirostris, Anchialina agilis, Scopelocheirus hopei and Philocheras bispinosus); an open slope assemblage (111 species, mainly amphipods and isopods; 249 ind./100 m2, 36% amphipods; dominant species: Disconectes phalangium, Munnopsurus atlanticus and Boreomysis arctica); a canyon E assemblage (129 species, mainly amphipods, mysids and cumaceans; 1172 ind./100 m2, 58% amphipods; dominant species: Melphidippa sp. B, Chelator insignis); a canyon E' assemblage (107 species, mainly amphipods and mysids; 507 ind./100 m2, 73% amphipods; dominant species: Cleonardopsis carinata, Bonnierella abyssorum, Rhachotropis caeca and Arcturopsis giardi); and a temporary canyon assemblage at site K (34 species, mainly amphipods and mysids; 899 ind./100 m2, 85% amphipods; dominant species: Tmetomyx similis, Caeconyx caeculus, Nebalia sp. A and Cleonardopsis carinata). Site K was sampled only four months after a turbidity event, detected on sediment cores (18 cm thick Bouma sequence) taken during the same cruise and triggered by the violent storm ('ouragan Martin', wind up to 200 km/h) which affected the French Atlantic coast on 27 December 1999. The corresponding suprabenthic assemblage showed evidence of deep structural changes after this catastrophic event, characterized by relative low

  7. A-type and I-type granitoids and mylonitic granites of Hassan Salaran area of SE Saqqez, Kurdistan, Iran

    Science.gov (United States)

    Abdullah, Fakhraddin Mohammad; Saeed Ahmad, Sheler

    2014-05-01

    The Hassan Salarn area is located 20km to southeast of Saqqez city in Kurdistan Province, western Iran. In this area there are two distinct granitic rock suites consisting A-type and I-type granites and also mylonitic granites. These A-type and I-type granites have various petrological and geochemical characteristics. They also have different origins and petrogenesis. A-type granitoids comprise alkali feldspar granite, syenogranite and quartz alkali feldspar syenite, whereas I-type granitoids are composed of monzogranite, granodiorite and tonalite. Geochemically, A-type granitoids are peralkaline and acmite-normative but I-type granitoids are subalkaline (calc-alkaline), metaluminous and diopside-normative. A-type granitoids are also ferroan alkali and ferroan alkali-calcic whereas I-type granitoids are magnesian and calcic. A-type granitoids resemble to within plate granites and post-orogenic granites whereas I-type granitoids resemble to volcanic arc granites. A-type granitoids contain higher concentrations of alkalies, Zr, Rb, Nb, Y, Th, Ce, high FeO/MgO ratios and lower concentrations of Mg, Ca and Sr, resembling post-orogenic A-type granites. It is possible that heat from a mantle-derived magma which intruded into the lower crust, and/or rapid crustal extension have been essential generation of approriate melts producing A-type granitoids. Thus we can conclude that A-type granitoids were generated from a mixed mantle-crust source. Negative Nb anomalies and low contents of Ti and P probably indicate a subduction-related origin for protolith of I-type granitoids. Negative Nb anomalies and enrichment in Ce relative to its adjacent elements can be related to involvement of continental crust in magmatic processes. I-type granitoids are also enriched in Rb, Ba, K, Th, Ce and depleted in Nb, Zr and Y, indicating that they have had interacted with crust. I-type granitoids may result from contamination of mantle-derived magmas by continental crust during a subduction

  8. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    International Nuclear Information System (INIS)

    Glynn, P.D.; Voss, C.I.

    1999-09-01

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO 3 composition at shallow depth to a CaCl 2 -rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured E H values are generally near -300 mV, and on average are only about 50 mV lower than E H values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m 2 per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the possible range of values

  9. SITE-94. Geochemical characterization of Simpevarp ground waters near the Aespoe Hard Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Glynn, P D; Voss, C I [US Geological Survey, Reston, VA (United States)

    1999-09-01

    The present report analyzes the geochemical data in order to evaluate collection and interpretation techniques that will be used to site the repository and to assess its safety. Ground waters near the Aespoe Hard Rock Laboratory (HRL) may be grouped into five chemically and isotopically distinct water types, on the basis of their deuterium and chloride contents: 1) recent waters, 2) 5 g/L chloride waters, 3) deep waters, 4) seawater imprint waters, and 5) glacial melt waters. The sampled ground waters show a progressive change from a predominantly NaHCO{sub 3} composition at shallow depth to a CaCl{sub 2}-rich composition at depth. Despite the proximity of the Baltic, relatively few of the sampled ground waters contain any evidence of a seawater component. This finding, together with the rather shallow depths at which saline waters were found, indicates that Aespoe island is presently in a regional ground-water discharge area. The chemical and isotopic composition of the sampled waters also indicates that local recharge of dilute recent waters occurs only down to shallow depths (generally less than 100 in). The Aespoe ground waters are sulfidic and do not presently contain any dissolved oxygen. Measured E{sub H} values are generally near -300 mV, and on average are only about 50 mV lower than E{sub H} values calculated from the sulfide/sulfate couple. Maintenance of reducing conditions, such as presently found at the Aespoe HRL, is an important consideration in assessing the performance of nuclear waste disposal sites. Measurements of dissolved radon and of uranium concentrations in fracture-fill materials were used to calculate an average effective flow-wetted surface area of 3.1 m{sup 2} per liter of water for the Aespoe site. Estimation of flow-wetted surface areas is essential in determining the importance of matrix diffusion and surface sorption processes for radionuclide release calculations. The Rn calculation technique shows promise in helping narrow the

  10. Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lunkka, J. P.; Moisio, K.; Vainio, A. [Univ. of Oulu (Finland)

    2013-07-15

    It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

  11. Subglacial hydrology of the lake district ice lobe during the Younger Dryas (ca. 12 500 - 11 600 years ago) in the Kylaeniemi area, SE Finland

    International Nuclear Information System (INIS)

    Lunkka, J. P.; Moisio, K.; Vainio, A.

    2013-07-01

    It is essential to gain knowledge on the subglacial hydrological conditions at the glacier bed / bedrock interface when assessing how bedrock fracture zones affect subglacial melt water flow and in which subglacial zones pressurized and oxygen-rich melt water penetrates into the bedrock fracture systems. In the warm-based glacier zones, a part of subglacial melt water will penetrate deep into the fracture systems although the major part of melt water is drained to and beyond the ice margin via subglacial tunnel networks especially in the areas where ice is flowing on the crystalline bedrock. During the last deglaciation phase of the former Scandinavian Ice Sheet, glaciofluvial accumulations were deposited and these sediment accumulations are highly important when picturing the subglacial hydrology of different ice streams during deglaciation in the crystalline bedrock area. The aim of the present work was to map the bedrock fracture zones in the Kylaeniemi area and to shed light on the subglacial hydrology of the Scandinavian Ice Sheet's Lake District Ice Stream that occupied the Kylaeniemi area during the Younger Dryas between ca. 12 500 - 11 600 years ago. The special emphasis within this general aim was to study the relationship between bedrock fracture zones and the routes of subglacial drainage paths. The methods used to map and study bedrock fracture zones and subglacial drainage paths included remotes sensing methods, field observations, ground penetrating radar (GPR) investigations and GIS-based reconstructions. Conventional geological field methods aided by the GPR-method were also used to map bedrock exposures and their structures and to define the type of glaciofluvial sediments and glaciofluvial landform associations. Two main fracture zone sets occur in the study area. The most prominent bedrock fracture zone set trends NW-SE while the other, less prominent fracture zone set is aligned in NE-SW direction. The majority of the minor joint sets in

  12. Meteorological, hydrological and hydrogeological monitoring data and near-surface hydrogeological properties data from Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Werner, Kent; Oehman, Johan; Holgersson, Bjoern; Roennback, Kristoffer; Marelius, Fredrick

    2008-12-01

    This report presents and analyses meteorological, hydrological and hydrogeological time-series data and near-surface hydrogeological properties data from the Laxemar-Simpevarp area, available in SKB's Sicada database at time of the Laxemar 2.3 data freeze (Aug. 31, 2007). The meteorological data set includes data from two local stations, located on the island of Aespoe and at Plittorp, located further inland. In addition, the data evaluation uses a longer-term data set from 7 surrounding stations, operated by SMHI. As part of this study, a time series is constructed of the water content of snow. According to the data evaluation, the site-average annual precipitation and potential evapotranspiration can be estimated to be on the order of 600 and 535 mm, respectively. In particular, precipitation demonstrates a near-coastal gradient, with less precipitation at the coast compared to areas further inland. The surface-water level data set includes data from 4 lake-level gauging stations and 3 sea-level gauging stations. All lakes are located above sea level, including the near-coastal Lake Soeraa. Hence, no intrusion of sea water to lakes takes place. There is a strong co-variation among the monitored lake-water levels, typically with maxima during spring and minima during late summer and early autumn. Concerning the sea as a hydraulic boundary, the maximum and minimum sea levels (daily averages) during the site-investigation period were -0.52 and 0.71 metres above sea level, respectively, whereas the average sea level was 0.03 metres above sea level (RHB 70). The data set on stream discharge, surface-water temperature and electrical conductivity includes data from 9 discharge-gauging stations in 7 streams. Based on the discharge data, the site-average specific discharge for the years 2005-2007 can be estimated to 165 mm/y, which is within the interval of the estimated long-term average. Overall, discharge-data errors are likely to be small. The hydrogeological time

  13. Meteorological, hydrological and hydrogeological monitoring data and near-surface hydrogeological properties data from Laxemar-Simpevarp. Site descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent (EmpTec, Taeby (Sweden)); Oehman, Johan (Golder Associates AB, Stockholm (Sweden)); Holgersson, Bjoern (SWECO VIAK, Stockholm (Sweden)); Roennback, Kristoffer (Aqualog AB, Goeteborg (Sweden)); Marelius, Fredrick (WSP Sverige, Stockholm (Sweden))

    2008-12-15

    This report presents and analyses meteorological, hydrological and hydrogeological time-series data and near-surface hydrogeological properties data from the Laxemar-Simpevarp area, available in SKB's Sicada database at time of the Laxemar 2.3 data freeze (Aug. 31, 2007). The meteorological data set includes data from two local stations, located on the island of Aespoe and at Plittorp, located further inland. In addition, the data evaluation uses a longer-term data set from 7 surrounding stations, operated by SMHI. As part of this study, a time series is constructed of the water content of snow. According to the data evaluation, the site-average annual precipitation and potential evapotranspiration can be estimated to be on the order of 600 and 535 mm, respectively. In particular, precipitation demonstrates a near-coastal gradient, with less precipitation at the coast compared to areas further inland. The surface-water level data set includes data from 4 lake-level gauging stations and 3 sea-level gauging stations. All lakes are located above sea level, including the near-coastal Lake Soeraa. Hence, no intrusion of sea water to lakes takes place. There is a strong co-variation among the monitored lake-water levels, typically with maxima during spring and minima during late summer and early autumn. Concerning the sea as a hydraulic boundary, the maximum and minimum sea levels (daily averages) during the site-investigation period were -0.52 and 0.71 metres above sea level, respectively, whereas the average sea level was 0.03 metres above sea level (RHB 70). The data set on stream discharge, surface-water temperature and electrical conductivity includes data from 9 discharge-gauging stations in 7 streams. Based on the discharge data, the site-average specific discharge for the years 2005-2007 can be estimated to 165 mm/y, which is within the interval of the estimated long-term average. Overall, discharge-data errors are likely to be small. The hydrogeological

  14. SE PREVENINDO?

    Directory of Open Access Journals (Sweden)

    Ana Débora Assis Moura

    2010-01-01

    Full Text Available Este estudio tuvo como objetivo verificar el comportamiento de las prostitutas en relación a la prevención de enfermedades de transmisión sexual y del Síndrome de Inmunodeficiencia Adquirida-SIDA, así como investigar cómo se previenen de esas enfermedades. Se trata de una investigación exploratoria, con enfoque cualitativo, llevada a cabo en la Asociación de las Prostitutas en Ceará, Brazil, en septiembre de 2008, a través de una encuesta con 25 prostitutas. El análisis de los datos se hizo según el análisis de contenido, después de ser agrupados en cuatro categorías: conocimiento sobre las enfermedades de transmisión sexual/SIDA; convivencia con la(s enfermedad(es; prevención de la enfermedad de transmisión sexual/SIDA; y el uso de drogas. Se concluyó que las prostitutas no usan preservativos en todas las relaciones sexuales, por lo tanto, las enfermedades de transmisión sexual representan una realidad; la desinformación sobre la(s enfermedad(es es notable; el consumo de drogas lícitas e ilícitas es frecuente entre ellas, factor que las expone a situaciones más vulnerables con relación al VIH/SIDA.

  15. Influence of Cu(In,Ga)(Se,S)2 surface treatments on the properties of 30 × 30 cm2 large area modules with atomic layer deposited Zn(O,S) buffers

    International Nuclear Information System (INIS)

    Merdes, S.; Steigert, A.; Ziem, F.; Lauermann, I.; Klenk, R.; Hergert, F.; Kaufmann, C.A.; Schlatmann, R.

    2015-01-01

    We report the effect of Cu(In,Ga)(Se,S) 2 absorber surface treatments on the properties of atomic layer deposited-Zn(O,S) buffered 30 × 30 cm 2 large area modules. The absorber is prepared by the sequential process. H 2 O and KCN solution treatments are investigated. The absorber surface treatment is found to influence significantly the open circuit voltage and the fill factor of the full modules. Light soaking related metastabilities are also found to depend on the type of treatment. While both H 2 O and KCN treatments are efficient at removing Se-oxides and Na 2 HCO 3 , the KCN treatment is found to remove additionally Ga-oxides and elemental Se that are detected on the surface of the absorber. A 30 × 30 cm 2 module aperture efficiency up to 12.3% could be achieved with KCN surface treatment of the absorber. - Highlights: • The Cu(In,Ga)(Se,S) 2 surface influences the Zn(O,S)-buffered module performance. • Surface treatment by H 2 O efficiently removes Se-oxides and sodium compounds. • KCN treatment of the absorber removes Se-oxides, Ga-oxides and elemental Se. • The devices' light soaking behavior depends on the absorber's surface chemistry. • A 30 × 30 cm 2 module efficiency of 12.3% is achieved with KCN treatment

  16. Modulation of metallothionein, pi-GST and Se-GPx mRNA expression in the freshwater bivalve Dreissena polymorpha transplanted into polluted areas

    Directory of Open Access Journals (Sweden)

    Périne Doyen

    2015-04-01

    Full Text Available Glutathione S-transferases (GST, glutathione peroxidases (GPx and metallothioneins (MT are essential components of cellular detoxication systems. We studied the expression of pi-GST, Se-GPx, and MT transcripts in the digestive gland of Dreissena polymorpha exposed to organic and metallic pollutants. Mussels from a control site were transplanted during 3, 15 and 30 days into the Moselle River, upstream and downstream to the confluence with the Fensch River, a tributary highly polluted by polycyclic aromatic hydrocarbons and heavy metals. Se-GPx and pi-GST mRNA expression increased in mussels transplanted into the upstream site, Se-GPx response being the earliest. These genes were also induced after 3-days exposure at the downstream site. These inductions suggest an adaptative response to an alteration of the environment. Moreover, at this site, a significant decrease of the expression of MT, pi-GST and Se-GPx transcripts was observed after 30 days which could correspond to an inefficiency of detoxification mecanisms. The results are in correlation with the levels of pollutants in the sediments and their bioaccumulation in mussels, they confirm the environmental deleterious impact of the pollutants carried by the Fensch River.

  17. Seawater quality assessment and identification of pollution sources along the central coastal area of Gabes Gulf (SE Tunisia): Evidence of industrial impact and implications for marine environment protection.

    Science.gov (United States)

    El Zrelli, Radhouan; Rabaoui, Lotfi; Ben Alaya, Mohsen; Daghbouj, Nabil; Castet, Sylvie; Besson, Philippe; Michel, Sylvain; Bejaoui, Nejla; Courjault-Radé, Pierre

    2018-02-01

    Temperature, pH and trace elements (F, P, Cr, Cu, Zn, Cd, and Pb) contents were determined in 16 stations as well as in 2 industrial and 2 domestic discharge sources, in the central coastal area of the Gulf of Gabes. Compared to the northern and southern areas of the study area, the highest contents of contaminants were reached in the central area which hosts the coastal industrial complex. The seawater in this central area was also found to be acid and of higher temperature. Based on the Water Pollution Index results, an increasing degradation gradient of the seawater quality was revealed from northern and/or southern stations to central ones, categorized as 'strongly to seriously affected'. Phosphogypsum wastes dumped by the Tunisian Chemical Group (GCT) seem to have continuously degraded the seawater quality in the study area. A rapid intervention is needed to stop the effects on the marine environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Water activities in Laxemar-Simpevarp. Organic field inventory, nature values classification and description of production land; Vattenverksamhet i Laxemar-Simpevarp. Ekologisk faeltinventering, naturvaerdesklassificering samt beskrivning av produktionsmark

    Energy Technology Data Exchange (ETDEWEB)

    Hamren, Ulrika; Collinder, Per (Ekologigruppen AB, Stockholm (Sweden))

    2010-10-15

    This report describes nature values, agricultural areas and forestry areas in Laxemar, for which there could be negative consequences due to groundwater diversion during construction and operation of a repository for spent nuclear fuel in the rock. In 2009, the Swedish Nuclear Fuel and Waste Management Co (SKB) chose Forsmark as site for the repository. This report hence concerns the non-chosen Laxemar site. The report describes results from map studies and comprehensive field investigations, in terms of geographical delineations, descriptions of characteristics and classifications of nature values for groundwater dependent of -favoured nature objects. The nature objects are located in an investigation area, which according to numerical flow modelling could be affected by groundwater-table drawdown due to groundwater diversion. The investigation area contains a number of valuable nature habitats, but no protected areas in the form of nature reserves or Natura 2000 areas. In the investigation area 67 nature objects have been identified, geographically delineated and classified according to their nature values. Of these nature objects, 32 consist of forest objects (including moist forests), 26 consist of wetland objects, and nine consist of surface waters (streams, lakes and ponds). The nature-value classifications of objects are primarily based on habitat rareness and worth of protection on a national scale, and their importance as habitats for rare and threatened species. None of the identified nature objects is judged to be of national value (class 1). 15 nature objects (forest objects) are judged to be of regional value (class 2), 18 objects of municipal value (class 3) and 34 objects are judged to be of local value (class 4). Most of the nature objects contain nature values that are associated to factors other than the level of the groundwater table, primarily previous land uses in the form of grazing and hay cutting. There are also values associated to valuable

  19. Seagrass stems with attached roots from the type area of the Maastrichtian Stage (NE Belgium, SE Netherlands) : Morphology, anatomy, and ecological aspects

    NARCIS (Netherlands)

    van der Ham, R.W.J.M.; van Konijnenburg-van Cittert, J.H.A.; Jagt, J.W.M.; Indeherberge, L.; Meuris, R.; Deckers, M.J.M.; Renkens, S.; Laffineur, J.

    Seagrasses are the only seed plants to have invaded marine environments successfully. Seagrass fossils are both rare and have received scant attention so far. However, among the limited number of plant fossils from marine strata in the Maastrichtian type area, remains of seagrasses are relatively

  20. Water activities in Laxemar-Simpevarp. Organic field inventory, nature values classification and description of production land

    International Nuclear Information System (INIS)

    Hamren, Ulrika; Collinder, Per

    2010-10-01

    This report describes nature values, agricultural areas and forestry areas in Laxemar, for which there could be negative consequences due to groundwater diversion during construction and operation of a repository for spent nuclear fuel in the rock. In 2009, the Swedish Nuclear Fuel and Waste Management Co (SKB) chose Forsmark as site for the repository. This report hence concerns the non-chosen Laxemar site. The report describes results from map studies and comprehensive field investigations, in terms of geographical delineations, descriptions of characteristics and classifications of nature values for groundwater dependent of -favoured nature objects. The nature objects are located in an investigation area, which according to numerical flow modelling could be affected by groundwater-table drawdown due to groundwater diversion. The investigation area contains a number of valuable nature habitats, but no protected areas in the form of nature reserves or Natura 2000 areas. In the investigation area 67 nature objects have been identified, geographically delineated and classified according to their nature values. Of these nature objects, 32 consist of forest objects (including moist forests), 26 consist of wetland objects, and nine consist of surface waters (streams, lakes and ponds). The nature-value classifications of objects are primarily based on habitat rareness and worth of protection on a national scale, and their importance as habitats for rare and threatened species. None of the identified nature objects is judged to be of national value (class 1). 15 nature objects (forest objects) are judged to be of regional value (class 2), 18 objects of municipal value (class 3) and 34 objects are judged to be of local value (class 4). Most of the nature objects contain nature values that are associated to factors other than the level of the groundwater table, primarily previous land uses in the form of grazing and hay cutting. There are also values associated to valuable

  1. Water Activities in Laxemar Simpevarp. The final disposal facility for spent nuclear fuel - removal of groundwater and water activities above ground; Vattenverksamhet i Laxemar-Simpevarp. Slutfoervarsanlaeggning foer anvaent kaernbraensle - bortledande av grundvatten samt vattenverksamheter ovan mark

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent (EmpTec (Sweden)); Hamren, Ulrika; Collinder, Per (Ekologigruppen AB (Sweden))

    2010-12-15

    This report concerns water operations (Chapter 11 in the Environmental Code) below and above ground associated with construction, operation, and decommissioning of a repository for spent nuclear fuel in Laxemar in the municipality of Oskarshamn. SKB has chosen Forsmark in the municipality of Oesthammar as site for the repository, and the report hence describes a non-chosen alternative. The report provides a comprehensive description of how the water operations would be executed, their hydrogeological and hydrological effects and the resulting consequences. The description is a background material for comparisons between the two sites in terms of water operations. The underground part of a repository in Laxemar would, among other things, consist of an access ramp and a repository area at a depth of approximately 500 metres. The construction, operation, and decommissioning phases would in total comprise a time period of 60-70 years. Inflowing groundwater would be diverted during construction and operation. The modelling tool MIKE SHE has been used to assess the effects of the groundwater diversion, for instance in terms of groundwater levels and stream discharges. According to MIKE SHE calculations for a hypothetical case with a fully open repository, the total groundwater inflow would be in the order of 55-90 litres per second depending on the permeability of the grouted zone around ramp, shafts and tunnels. In reality, the whole repository would not be open simultaneously, and the inflow would therefore be less. The groundwater diversion would cause groundwater- level drawdown in the rock, which in turn would lead to drawdown of the groundwater table in relatively large areas above and around the repository. According to model calculations, there would be an insignificant drawdown of the water level in Lake Frisksjoen, the largest lake in the area. The discharge in the most important stream of the area (Laxemaraan) would be reduced by less than ten percent

  2. Behavior of uranium and thorium isotopes in soils of the Boreon area, Mercantour Massif (S.E. France). Leaching and weathering rate modeling

    International Nuclear Information System (INIS)

    Rezzoug, S.; Michel, H.; Barci-Funel, G.; Barci, V.; Fernex, F.

    2009-01-01

    Four cores were collected in weathered rocks and soils in the Boreon forest area (1765 m, Mercantour Massif, France). The samples were analyzed for the isotopes 230 Th, 232 Th, 234 U and 238 U. The activity and isotopic ratio profiles suggest that uranium was mobilized (leaching and precipitation) during the weathering process, as well as thorium but in a much less proportion. A model was drawn up to evaluate the U leaching rate and the time that some levels of the weathered rocks have been subjected to weathering. It utilizes LATHAM and SCHWARCZ's two equations,15 expressed as 234 U/ 238 U and 230 Th/ 238 U activity ratios, which assume that the alpha recoil effect allows easier leaching for 234 U than 238 U and no Th mobility. But this last assumption does not correspond to the observations made in the Boreon area, since it appears that in some soil deeper layers 230 Th and 228 Th are in radioactive deficit relatively to their parents. As there are four unknown quantities (the time, the leaching rates of 238 U, 234 U, 230 Th), the problem to be solved requires two more equations; these can be obtained utilizing the U activity ratio in water, and taking into account the 232 Th behavior. In some sites the 238 U leaching rate is high in deeper soil levels (near the fresh rocks); this would correspond to a loss of half the U amount in less than 24 000 years. (author)

  3. Impact of land-use change on soil degradation by establishment of terraces with subtropical orchards in sloping areas (Granada, SE Spain)

    International Nuclear Information System (INIS)

    Rodriguez Pleguezuelo, C. R.; Duran Zuzo, V. H.; Martin Peinado, F. J.; Franco Tarifa, D.

    2009-01-01

    In the coast of Granada, an intensive irrigated agriculture based on subtropical crops has been established. These trees have been planted in highly sloped areas, by the construction of terraces. In this fragile Mediterranean agroecosystem, the removal of native spontaneous vegetation cover and substitution by orchards, increase the susceptibility to soil degradation and eventually brings up the destruction of these structures by rainfall events. To study this net change, we monitored the soil loss and runoff over a two-year period in the taluses of terraces with a mature mango (Mangifera indica L.) orchard. The studied treatments were bare soil (BS) and spontaneous vegetation (NSV), each twice replicated. The erosion plots were 4 m x 4 m in area and were located in the taluses of orchard in the taluses of orchard terraces (65 degree centigrade slope). The average annual soil loss by erosion for BS and NSV was 2.5 and 0.3 Mg ha - 1 yr - 1, and for runoff 34.1 and 6.8 mm yr - 1, respectively. Therefore, soil erosion and runoff from BS plot were 8- and 5-times higher than in NSV, showing the importance of plant covers in the taluses of terraces in reducing this impact. Thus, the removal of plant cover from the taluses under these conditions, represent a high risk of slump and collapse, causing serious environmental and economic problems for farmers of subtropical crops. (Author) 11 refs.

  4. Impact of land-use change on soil degradation by establishment of terraces with subtropical orchards in sloping areas (Granada, SE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Pleguezuelo, C. R.; Duran Zuzo, V. H.; Martin Peinado, F. J.; Franco Tarifa, D.

    2009-07-01

    In the coast of Granada, an intensive irrigated agriculture based on subtropical crops has been established. These trees have been planted in highly sloped areas, by the construction of terraces. In this fragile Mediterranean agroecosystem, the removal of native spontaneous vegetation cover and substitution by orchards, increase the susceptibility to soil degradation and eventually brings up the destruction of these structures by rainfall events. To study this net change, we monitored the soil loss and runoff over a two-year period in the taluses of terraces with a mature mango (Mangifera indica L.) orchard. The studied treatments were bare soil (BS) and spontaneous vegetation (NSV), each twice replicated. The erosion plots were 4 m x 4 m in area and were located in the taluses of orchard in the taluses of orchard terraces (65 degree centigrade slope). The average annual soil loss by erosion for BS and NSV was 2.5 and 0.3 Mg ha{sup -}1 yr{sup -}1, and for runoff 34.1 and 6.8 mm yr{sup -}1, respectively. Therefore, soil erosion and runoff from BS plot were 8- and 5-times higher than in NSV, showing the importance of plant covers in the taluses of terraces in reducing this impact. Thus, the removal of plant cover from the taluses under these conditions, represent a high risk of slump and collapse, causing serious environmental and economic problems for farmers of subtropical crops. (Author) 11 refs.

  5. Proterozoic to Quaternary events of fracture mineralisation and oxidation in SE Sweden

    International Nuclear Information System (INIS)

    Drake, Henrik

    2008-12-01

    Fracture minerals and altered wall rock have been analysed to reveal the low-temperature evolution, especially regarding redox conditions, of the Simpevarp area, SE Sweden. This area is one of the two areas in Sweden investigated by the Swedish Nuclear fuel and Waste Management Co. in order to find a potential geological repository for spent nuclear fuel. The 1.8 Ga granitic to dioritic rocks in the area are generally un-metamorphosed and structurally well-preserved, although low-grade ductile shear zones and repeatedly reactivated fractures exist. Investigations of cross-cutting fractures along with a wide variety of fracture mineral analyses, such as stable isotopes and 40Ar/39Ar geochronology, have been used to distinguish a sequence of fracture filling generations. The characteristics of these generations indicate the low-temperature evolution of the area, including information of e.g. fluid origin, formation temperature, paleo stresses and relation to known geological events. Knowledge of the fracture mineral evolution is important for the conceptual geological and hydrogeochemical understanding of the site and supports predictions of future scenarios in the safety assessment. The fracture mineral generations identified have been formed at widely varying conditions starting in the Proterozoic with formation from inorganic hydrothermal fluids, continuing in the Paleozoic with formation from lower temperature brine type fluids with organic influence, and ranging into minerals formed from waters of varying salinity and with significant organic influence at conditions similar to the present conditions. However, the amount of potentially recent precipitates is very small compared to Proterozoic and Paleozoic precipitates. The fracture mineral parageneses have been associated, with varying confidence, to far-field effects of at least four different orogenies; the Svecokarelian orogeny (>1.75 Ga), the Danapolonian orogeny (∼1.47-1.44 Ga), the Sveconorwegian orogeny

  6. Hg contents in soils and olive-tree (Olea Europea, L.) leaves from an area affected by elemental mercury pollution (Jódar, SE Spain).

    Science.gov (United States)

    López-Berdonces, Miguel Angel; María Esbrí, José; Amorós, José Angel; Lorenzo, Saturnino; Fernández-Calderón, Sergio; Higueras, Pablo; Perez-de-los-Reyes, Caridad

    2014-05-01

    Data from soil and olive tree leaves around a decommissioned chlor-alkali plant are presented in this communication. The factory was active in the period 1977-1991, producing during these years a heavily pollution of Guadalquivir River and hydrargyrism in more than local 45 workers. It is located at 7 km South of Jódar, a locality with some 12,120 inhabitants. Mercury usage was general in this type of plants, but at present it is being replaced by other types of technologies, due to the risks of mercury usage in personal and environment. A soil geochemistry survey was carried out in the area, along with the analysis of olive-tree leaves (in the plots with this culture) from the same area. 73 soil samples were taken at two different depths (0-15 cm and 15-30 cm), together with 41 olive tree samples. Mercury content of geologic and biologic samples was determined by means of Atomic Absorption Spectrometry with Zeeman Effect, using a Lumex RA-915+ device with the RP-91C pyrolysis attachment. Air surveys were carried our using a RA-915M Lumex portable analytical device. Soil mercury contents were higher in topsoil than in the deeper soil samples, indicating that incorporation of mercury was due to dry and wet deposition of mercury vapors emitted from the plant. Average content in topsoil is 564.5 ng g-1. Hg contents in olive-tree leaves were in the range 46 - 453 ng g-1, with an average of 160.6 ng g-1. This level is slightly lower than tolerable level for agronomic crops established by Kabata-Pendias (2001) in 200 ng g-1. We have also compared soil and leaf contents for each sampling site, finding a positive and significant correlation (R=0.49), indicating that Hg contents in the leaves are linked to Hg contents in the soils. BAC (Bioaccumulation Absorption Coefficient, calculated as ratio between soil and leaf concentration) is 0.28 (consistent with world references, BAC = 0.7), considered "medium" in comparison with other mineral elements. Main conclusions of this

  7. Difference in particle transport between two coastal areas in the Baltic Sea investigated with high-resolution trajectory modeling.

    Science.gov (United States)

    Corell, Hanna; Döös, Kristofer

    2013-05-01

    A particle-tracking model based on high-resolution ocean flow data was used to investigate particle residence times and spatial distribution of settling sediment for two geo-morphologically different Swedish coastal areas. The study was a part of a safety assessment for the location of a future nuclear-waste repository, and information about the particle-transport patterns can contribute to predictions of the fate of a possible leakage. It is also, to our knowledge, the first time particle-transport differences between two coastal areas have been quantified in this manner. In Forsmark, a funnel-shaped bay shielded by a number of islands, the average residence time for clay particles was 5 times longer than in the modeled part of Simpevarp, which is open to the Baltic Sea. In Forsmark, <10 % of the released particles left the domain compared to 60-80 % in Simpevarp. These site-specific differences will increase over time with the differences in land uplift between the areas.

  8. Difference in Particle Transport Between Two Coastal Areas in the Baltic Sea Investigated with High-Resolution Trajectory Modeling

    International Nuclear Information System (INIS)

    Corell, Hanna; Doeoes, Kristofer

    2013-01-01

    A particle-tracking model based on high-resolution ocean flow data was used to investigate particle residence times and spatial distribution of settling sediment for two geo-morphologically different Swedish coastal areas. The study was a part of a safety assessment for the location of a future nuclear-waste repository, and information about the particle-transport patterns can contribute to predictions of the fate of a possible leakage. It is also, to our knowledge, the first time particle-transport differences between two coastal areas have been quantified in this manner. In Forsmark, a funnel-shaped bay shielded by a number of islands, the average residence time for clay particles was 5 times longer than in the modeled part of Simpevarp, which is open to the Baltic Sea. In Forsmark, <10 % of the released particles left the domain compared to 60-80 % in Simpevarp. These site-specific differences will increase over time with the differences in land uplift between the areas

  9. Water Activities in Laxemar Simpevarp. Clab/encapsulation facility (Clink) - removal of groundwater, collection of cooling water from the sea and the construction of day water pond; Vattenverksamhet i Laxemar-Simpevarp. Clab/inkapslingsanlaeggning (Clink) - bortledande av grundvatten, uttag av kylvatten fraan havet samt anlaeggande av dagvattendamm

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Kent (EmpTec (Sweden))

    2010-09-15

    This report is an appendix to an Environmental Impact Assessment that accompanies a permit application according to the Swedish Environmental Code. The report concerns water operations (Chapter 11 in the Environmental Code) associated with construction of an encapsulation plant in direct connection to SKB's existing Clab facility on the Simpevarp peninsula in the Municipality of Oskarshamn (the report is also included in the permit application according to the Nuclear Activities Act). Moreover, the report deals with water operations associated with the operation of the integrated facility, which is named Clink. Specifically, the water operations that are treated in the report include diversion of groundwater, withdrawal of cooling water from the sea, and construction of a storm-water treatment pond. There are valid permits regarding diversion of groundwater and withdrawal of cooling water for the current facility and activities at Clab. It is presupposed that the cooling-water withdrawal from the sea to Clink can be handled within the limits of the valid Clab permit. The diversion of groundwater from Clink may be somewhat larger compared to the present diversion from Clab. The increase is due to a relatively small, additional rock shaft for the encapsulation plant, adjacent to the current surface facility and above one of the two existing rock caverns (Clab 1). Based on the location of the planned rock shaft (above one of the existing rock caverns) and its small volume, it is judged that the inflow of groundwater during operation of Clink will be only 5-10 percent larger compared to the inflow to the current Clab facility. It is possible that the inflow will be larger during the construction phase, prior to grouting of the shaft. Based on the limited increase of the groundwater inflow and results from the ongoing Clab monitoring programme, it is judged that the construction of the encapsulation plant and the operation of Clink will only lead to very small

  10. Swedish Hard Rock Laboratory first evaluation of preinvestigations 1986-87 and target area characterization

    International Nuclear Information System (INIS)

    Gustafson, G.; Stanfors, R.; Wikberg, P.

    1988-06-01

    SKB plans to site an underground research laboratory in the Simpevarp area. A regional survey started in 1986 and an extensive programme for geology, geohydrology and hydrochemistry was carried through. This report gives an evaluation of all available data gathered from the start of the project up to the drilling of core boreholes in some target areas in the autumn of 1987. A descriptive geological-tectonic model on a regional scale is presented that is intended to constitute a basis for the hydrogeological modelling work. Preliminary rock mass descriptions are also presented on a more detailed scale for some minor parts of the area. It is recommended that the island Aespoe is the principal target area for the continued work on the Swedish Hard Rock Laboratory. (orig.)

  11. Contenha-se, se for capaz

    Directory of Open Access Journals (Sweden)

    Mirna Feitoza Pereira

    2008-11-01

    Full Text Available Em O Instinto da Linguagem, Steven Pinker discorre sobre sua célebre tese: a linguagem não é a mais prodigiosa invenção cultural humana. Ela é uma peça da constituição biológica do cérebro. A linguagem é uma habilidade complexa e especializada, que se desenvolve espontaneamente na criança, sem qualquer esforço consciente ou instrução formal, que se manifesta sem que se perceba sua lógica subjacente, que é qualitativamente a mesma em todo indiví­duo, e que difere de capacidades mais gerais de processamento de informações ou de comportamento inteligente. Para Pinker, a concepção de linguagem como um tipo de instinto transmite a idéia de que as pessoas sabem falar mais ou menos da mesma maneira que as aranhas sabem tecer suas teias. Ele apóia suas idéias em Darwin e Chomsky. Palavras-chave linguagem, gramática universal, evolução Abstract In Language Instinct, Steven Pinker argues about his famous thesis: language is not the most prodigious human cultural invention. It is a distinct piece of the biological constitution of the brain. Language is a complex, specialized skill, which develops spontaneously in the child, without conscious effort or formal instruction. It reveals itself without awareness of its underlying logic, which is qualitatively the same in every individual, and which is distinct from more general abilities of information processing of intelligent behavior. According to Pinker, the conception of language as a kind of instinct conveys the idea that people know how to talk in more or less the same way as spiders know how to spin webs. His thesis is founded in Darwin and Chomsky-s theories. Keywords language, universal grammar, evolution

  12. Assessment report: Application from OKG AB for a license according to the Act on Nuclear Activities concerning a shallow land burial/landfill for low-level nuclear waste in Simpevarp in the Oskarshamn municipality

    International Nuclear Information System (INIS)

    Lindbom, G.; Wiebert, A.; Norden, M.; Larsson, Carl-Magnus; Loefgren, T.; Lumpus, J.

    2000-10-01

    OKG AB has to SSI submitted an application for a license according to the Act on Nuclear Activities (1984:3) concerning a shallow land burial/landfill for low-level nuclear waste in Simpevarp in the Oskarshamn municipality. The application for a license covers permission to build, possess and operate a shallow land burial/landfill for low-level nuclear waste. Attached to the application is an environmental impact statement. An application for a license according to the Environmental Act (1998:808) has been submitted to the Environmental Court in Vaexjoe. SSI has circulated the application for consideration to the Swedish Nuclear Power Inspectorate, the Swedish Environmental Protection Agency, the County Government Board of Kalmar and the Oskarshamn municipality. SSI has informed the European Commission about the application in accordance with the EURATOM Treaty, article 37. This assessment report constitutes the base for the decision by SSI 2000-09-18 for approval and radiation protection conditions. In the report, earlier permissions for shallow land burials/landfills at the Swedish nuclear installations are described. This report shows the development of the legal system during the last years, the premises for the assessment of the application, and SSI's review of OKG's plans, consequence analysis and environmental impact statement

  13. Future strategy of SE

    International Nuclear Information System (INIS)

    Arcelli, M.

    2006-01-01

    In this presentation author (General Director of Slovenske elektrarne, a. s.) presents structure and investment plans of SE. The feasibility study of construction of the blocks 3 and 4 of the Mochovce NPP is presented

  14. SE-VYZ

    International Nuclear Information System (INIS)

    Anon

    2004-01-01

    On this CD compact disc 6 video-films (A-1 NPP; Bituminization; Cementation; Pressing; The Interim spent fuel storage facility; Transport into the National radioactive waste repository Mochovce; Ignition; and Vitrification). In these films process of radioactive waste treatment in the Bohunice Radioactive Waste Processing Center (SE-VYZ) is presented. 2 presentations about radioactive wastes treatment in the SE-VYZ are included

  15. SE debt restructuring plan

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    Slovenske elektrarne, a.s. (SE) plans to restructure one's own debts in 2003-2005. Debt restructuring plan is following: 2003: Collection of pre-payment on electricity - 60 million Euro (2.5 billion Slovak crowns), consumer unknown. Own promissory notes in total value of 100 million US$ (3.5 billion Slovak crowns) - in process. Sale of claims worth 2.4 billion Slovak crowns (57.21 million Euro) - negotiations in process. 2003/2004: Restructuring of loans payable IV. quarter 2003 and at the beginning of 2004 in value of 200 million Euro (8.3 billion Slovak crowns). Aim of SE is a new credit payable within 7 years, with instalments payable in the last two to three without any state subsidies. 2005: Loans worth 460 million Euro (189 billion Slovak crowns) will still remain. SE want to negotiate them with banks without state support

  16. Autismos que se 'curan'

    OpenAIRE

    Artigas, Josep, 1948-; Paula Pérez, Isabel, 1970-

    2016-01-01

    Introducción. La investigación sobre el autismo, basada principalmente en el modelo categórico del Manual diagnóstico y estadístico de los trastornos mentales, se ha centrado de forma preferente en la epidemiología, las manifestaciones clínicas, los mecanismos cognitivos y los determinantes biológicos y ambientales; sin embargo, se ha prestado escaso interés a las trayectorias evolutivas, las cuales son decisivas de cara al pronóstico a medio y largo plazo. Objetivo. Revisar el curso evolutiv...

  17. Se comunican los investigadores

    OpenAIRE

    Rafael Roncagliolo

    2015-01-01

    En Brasil se reunieron los investigadores de la comunicación de América Latina y del mundo (1992) El encuentro Latinoamericano fue en Embú-Guacú, poblado de la periferia de Sao Paulo, y el encuentro Mundial en Guarujá, balneario cercano al Puerto de Santos. La amplitud de la participación y la diversidad de temas y enfoques son indicios del desarrollo y dinamismo de la profesión.

  18. Se comunican los investigadores

    Directory of Open Access Journals (Sweden)

    Rafael Roncagliolo

    2015-01-01

    Full Text Available En Brasil se reunieron los investigadores de la comunicación de América Latina y del mundo (1992 El encuentro Latinoamericano fue en Embú-Guacú, poblado de la periferia de Sao Paulo, y el encuentro Mundial en Guarujá, balneario cercano al Puerto de Santos. La amplitud de la participación y la diversidad de temas y enfoques son indicios del desarrollo y dinamismo de la profesión.

  19. ZnSe/ZnSeTe Superlattice Nanotips

    Directory of Open Access Journals (Sweden)

    Young SJ

    2010-01-01

    Full Text Available Abstract The authors report the growth of ZnSe/ZnSeTe superlattice nanotips on oxidized Si(100 substrate. It was found the nanotips exhibit mixture of cubic zinc-blende and hexagonal wurtzite structures. It was also found that photoluminescence intensities observed from the ZnSe/ZnSeTe superlattice nanotips were much larger than that observed from the homogeneous ZnSeTe nanotips. Furthermore, it was found that activation energies for the ZnSe/ZnSeTe superlattice nanotips with well widths of 16, 20, and 24 nm were 76, 46, and 19 meV, respectively.

  20. Interaction of Se and GaSe with Si(111)

    International Nuclear Information System (INIS)

    Meng, Shuang; Schroeder, B. R.; Olmstead, Marjorie A.

    2000-01-01

    Deposition of Se and GaSe on Si(111)7x7 surfaces was studied with low-energy electron diffraction, x-ray photoelectron spectroscopy, and x-ray photoelectron diffraction to probe initial nucleation and interface structure for GaSe/Si(111) heteroepitaxy. Room-temperature deposition of Se on Si(111)7x7 results in an amorphous film. Subsequent annealing leads to Se evaporation without ordering or interdiffusion. Se deposition at 450 degree sign C saturates at submonolayer coverage with no diffusion of Se into the substrate. There is no clear evidence of ordered sites for the Se. Growth of GaSe on Si(111)7x7 above 500 degree sign C results in a pseudomorphic bilayer, with Si-Ga-Se bonding. Additional GaSe does not stick to the bilayer above 525 degree sign C. The resulting Se lone pair at the surface leads to an ideally passivated surface similar to As/Si(111). This stable surface is similar to the layer termination in bulk GaSe. The single domain bilayer is oriented with the Ga-Se bond parallel to the substrate Si-Si bond. (c) 2000 The American Physical Society

  1. Exploring SE for Android

    CERN Document Server

    Confer, William

    2015-01-01

    This book is intended for developers and engineers with some familiarity of operating system concepts as implemented by Linux. A basic background in C code would be helpful. Their positions range from hobbyists wanting to secure their Android powered creations to OEM engineers building handsets to engineers of emerging areas where Android is seeing growth.

  2. Effect of nonstoichiometry properties of CuInSe2

    International Nuclear Information System (INIS)

    Rogacheva, E.I.; Tavrina, T.V.

    1997-01-01

    The homogeneity area size of the CuInSe 2 semiconductor compound is determined by the (CuIn)-Se profile of the Cu-In-Se ternary system at 350 deg C. The microhardness and thermo-electromotive force dependences on Se content are studied after various kind of thermal treatment. Interpretation of the results obtained is given with and account of defects formation character by deviations from stoichiometry [ru

  3. Extended analyses of Se VII and Se VIII

    International Nuclear Information System (INIS)

    Vankleef, Th.A.M.; Joshi, Y.N.

    1984-01-01

    Joshi et al. (1984) have conducted an analysis of the 3d8 4s-3d8 4p transitions in As VII. The present investigation is concerned with an analysis of similar transitions in Se VIII. The selenium spectrum was photographed in the 400-1200-A wavelength region on a variety of normal-incidence spectrographs. Attention is given to least-squares-fit (LSF) and Hartree-Fock (HF) parameter values for the 3d9 4d configuration of Se VII, LSF and HF parameter values for the 3d8 4s and 3d8 4p configurations of Se VIII, the energy and composition of the levels of the 3d9 4d configuration of Se VII, classified lines in Se VII, energy levels and composition of the 3d8 4s configuration and the revised and newly determined levels of the 3d8 4p configuration of Se VIII, and newly classified lines of Se VIII. 15 references

  4. PHEIFFER SE TAALPOLITIEK JC Steyn

    African Journals Online (AJOL)

    sigself maak tog nie Chomsky se teorie oor n aangebore taalaanleg en die konsekwensie daarvan nl. dat elke taal opgebou moet wees volgens dieselfde grondprinsipes, ongeldig nie? Taalpolitieke oortuigingskrag het hierdie argument nog minder. Sal jy in alle erns vir mense kan se: "Ons moet aanhou om die taal te praat ...

  5. Recharge-area nuclear waste repository in southeastern Sweden. Demonstration of hydrogeologic siting concepts and techniques

    International Nuclear Information System (INIS)

    Provost, A.M.; Voss, C.I.

    2001-11-01

    sites are evaluated using a three-dimensional, variable-density flow and solute transport model of southeastern Sweden under present interglacial conditions. The analysis considers four structural models of the bedrock that represent the possible range of regional anisotropy in permeability. Results indicate that potential repository sites at Hultsfred and another comparison site have travel times ten times or longer than sites at Simpevarp and Oskarshamn, and at worst, have travel times equivalent to the latter sites. Potential repository sites at Simpevarp and Oskarshamn have flow paths of less than 3 kilometers (lower values cannot be resolved by the current model), while the Hultsfred and comparison sites have path lengths ranging from 25 kilometers to 130 kilometers, and much greater flow path volumes. Given the uncertainties in bedrock structure, thus, it is more likely that the Hultsfred site will provide greater flow path, travel time, and flow path volume than the coastal Simpevarp and Oskarshamn sites, and may therefore be preferable in terms of the hydrogeologic safety margin. Additionally, there are other repository locations in southeastern Sweden, such as the comparison site, that improve substantially on the Hultsfred site. Three techniques are introduced for illuminating important aspects of the three-dimensional flow field in a numerical model. (1) A technique for tracing the flow paths and flow path volume from potential repository sites in a three-dimensional variable-density ground-water model involves a solute transport simulation that fills the flow tube passing through the repository with a non-zero concentration. (2) Recharge areas may be mapped in the model by means of a transport simulation that delineates where inflow occurs to the top surface of the model. (3) Travel times may be determined in a 'return-flow time' transport simulation, in which the flow field is reversed and the solute undergoes a zero-order production rate of one per year

  6. Sample Set (SE): SE10 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE10 Effect of phosphorus nutrition for cabbage metabolites Investigation of Brassi...ca oleracea var. capitata Hatukoi leaf metabolites. 3 growth conditions (high, low and no phosphorus nutrition

  7. Sample Set (SE): SE30 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE30 Comparison of seed metabolites among soybean varieties Investigation of Glycine max. green seed metabol...ites. 3 varieties (Kamogawashichiri, Koitozairai, Tanbakuro) data are examined. Tak

  8. Sample Set (SE): SE13 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE13 Comparison of leaf metabolites among spinach varieties Investigation of Spinacia oleracea leaf metaboli...tes. 4 cultivers (Nihon, Kanaji, Kurohaminstarland and Wasesaradaakari) and 3 repli

  9. Sample Set (SE): SE31 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE31 Comparison of seed metabolites among eggplant fruit tissues Investigation of S...olanum melongena Senryounigou metabolites. 3 tissues (flesh, fruit, peel) data are examined. Takeshi Ara 1,

  10. Sample Set (SE): SE28 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE28 Comparison of leaf metabolites among developmental stages of Hevea brasiliensi...s Investigation of Hevea brasiliensis leaf metabolites. 4 developmental stages and 6 replicates data are exa

  11. Sample Set (SE): SE53 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE53 Covering chemical diversity of genetically-modified tomatoes using metabolomics...signature. We conclude that multi-platform metabolomics is an approach that is both sensitive and robust and

  12. Sample Set (SE): SE26 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE26 Effect of compost for cabbage metabolites Investigation of Brassica oleracea v...ar. capitata YR Seisyun leaf metabolites. 2 growth conditions (with or without 6t compost treatment) and 3 r

  13. Sample Set (SE): SE20 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE20 Arabidopsis thaliana leaf metabolite analysis for a software test Investigatio...es that were investigated to optimize the parameters of PowerGet software for better metabolite annotation i

  14. Sample Set (SE): SE16 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE16 Effect of agricultural films for spinach leaf metabolites 2 Investigation of S...pinacia oleracea leaf metabolites. 3 growth conditions (covered with normal or UV cut agricultural film or no agricultura

  15. Sample Set (SE): SE14 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE14 Effect of agricultural films for tomato fruit metabolites Investigation of Sol...anum lycopersicum fruit metabolites. 3 growth conditions (covered with normal or UV cut agricultural film or no agricultura

  16. Sample Set (SE): SE18 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available in by Orbitrap MS and automated search engine Lipid Search A comprehensive and precise identification of pho...SE18 Global identification of phospholipid molecular species in mouse liver and bra

  17. Quantitative analysis of Terminal Restriction Fragment Length Polymorphism (T-RFLP microbial community profiles: peak height data showed to be more reproducible than peak area Análise quantitativa de perfis de T-RFLP de comunidades microbianas: dados de altura de picos mostraram-se mais reprodutíveis do que os de área

    Directory of Open Access Journals (Sweden)

    Roberto A. Caffaro-Filho

    2007-12-01

    Full Text Available Terminal Restriction Fragment Length Polymorphism (T-RFLP is a culture-independent fingerprinting method for microbial community analysis. Profiles generated by an automated electrophoresis system can be analysed quantitatively using either peak height or peak area data. Statistical testing demontrated that peak height data showed to be more reproducible than peak area data.Terminal Restriction Fragment Length Polymorphism (T-RFLP é um método molecular, independente de cultivo, para análise de comunidades microbianas. Perfis gerados por um sistema automatizado de eletroforese podem ser analisados quantitativamente usando dados de altura ou área dos picos. Os dados de altura mostraram-se mais reprodutíveis do que os de área.

  18. Señas Mexicano

    Directory of Open Access Journals (Sweden)

    Juan F. García Mejía

    2007-01-01

    Full Text Available En este artículo se muestra un sistema que permite el estudio y práctica del Lenguaje de Señas Mexicano (LMS, el cual es el método de comunicación de las personas que padecen un trastorno de procesamiento auditivo. El sistema propuesto en este artículo consta de un guante de tela instrumentado con sensores de flexión, una etapa de acondicionamiento de señales y una tarjeta de adquisición de datos; que en su conjunto constituyen el Hardware. El software esta formado por un programa de adquisición de datos y una interfaz de usuario, ambos codificados en Visual Basic Net. El sistema propuesto se modela por medio del lenguaje de modelado unificado (UML, ya que Visual Basic es un lenguaje orientado a eventos.

  19. Porøse materialer

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    2000-01-01

    Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM).......Dette undervisningsnotat er en samling af noter, der refererer til den indledende del af kurset Materialmekanik og Porøse materailer på Insitut for Bærende Konstruktiner og Materialer (BKM)....

  20. Sample Set (SE): SE50 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available oids We report that flavonoids with radical scavenging activity mitigate against ox...ress. These data confirm the usefulness of flavonoids for enhancing both biotic and abiotic stress tolerance...SE50 Enhancement of oxidative and drought tolerance in arabidopsis by overaccumulation of antioxidant flavon

  1. Sample Set (SE): SE59 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available idopsis thaliana (Arabidopsis). However, the behavior of flavonoids during drough...t stress is still not well documented. Herein we investigated the time-series alternation of flavonoids in t...vonoids, a class of specialized metabolites, including flavonols and anthocyanins w...SE59 Alternation of flavonoid accumulation under drought stress in Arabidopsis thaliana We reported that fla

  2. Sample Set (SE): SE27 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE27 Effect of agricultural films for cabbage leaf metabolites Investigation of Bra...ssica oleracea var. capitata YR Tenkuu leaf metabolites. 3 growth conditions (covered with normal or UV cut agricultura...l film or no agricultural film), 3 replicates data are examined. Takeshi Ara 1, Naoki Yamamoto 1,

  3. Sample Set (SE): SE52 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE52 Mass spectra-based framework for automated structural elucidation of metabolom...e data to explore phytochemical diversity A novel framework for automated elucidation of metabolite structur...te ontology system was also introduced to attain putative characterization of the metabolite signals.The automate

  4. Ud at se med Erasmus

    DEFF Research Database (Denmark)

    Frandsen, Pernille

    2009-01-01

    Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus.......Få lidt luft under vingerne, kom ud at møde udenlandske kolleger og se, hvordan man også kan lave uddannelsesbibliotek. Med begejstring fortæller tre bibliotekarer om deres oplevelser i det store udland – alt sammen finansieret af Erasmus....

  5. Ud & se - med Claude Monet

    DEFF Research Database (Denmark)

    Bonde, Lisbeth

    2015-01-01

    Udstillingen 'Claude Monet - Lost in Translation - på ARoS stiller ind på Claud Monet og hans samtidige malerkolleger. Udstillingen forsøger at "genlæse" Monet fra et samtidskunstnerisk perspektiv - og vurderer hans indsats, inden hans værker er blevet reproduceret ihjel....

  6. X = S, Se, Te) heterostructures

    KAUST Repository

    Zhang, Qingyun; Schwingenschlö gl, Udo

    2018-01-01

    Using first-principles calculations, we investigate the electronic properties of the two-dimensional GaX/MX2 (M = Mo, W; X = S, Se, Te) heterostructures. Orbital hybridization between GaX and MX2 is found to result in Rashba splitting at the valence

  7. Sample Set (SE): SE47 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE47 Metabolomic correlation-network modules in Arabidopsis based on a graph-cluste...as a system. Typical metabolomics data show a few but significant correlations among metabolite levels when ...itions. Although several studies have assessed topologies in metabolomic correlation networks, it remains un... (mto1), and transparent testa4 (tt4) to compare systematically the metabolomic correlation...s in samples of roots and aerial parts. We then applied graph clustering to the constructed correlation

  8. Hablando se entiende la gente

    Directory of Open Access Journals (Sweden)

    Mila Crespo Picó

    2012-08-01

    Full Text Available Habiendo observado que muchos cursos centrados en el desarrollo de la competencia comunicativa oral se limitan a ofrecer actividades inconexas que suponen un gran esfuerzo por parte de los participantes para situarse ante cada actividad y dificultan el establecimiento de relaciones profundas entre los exponentes nociofuncionales, los objetivos comunicativos y los recursos lingüísticos necesarios para realizarlas por contar con un tiempo limitado en el aula para ello, se presentó, bajo el mismo título que esta comunicación, una propuesta didáctica para un curso de conversación que pretende paliar estos aspectos en el I Foro de Profesores de E/LE en la Universitat de València.

  9. Die verpleegster se terapeutiese funksie

    Directory of Open Access Journals (Sweden)

    D.C. Harrington

    1980-09-01

    Full Text Available Ons sou hierdie praatjie graag wou inlei met Virginia Henderson se definisie van verpleging: “ The unique function of the nurse is to assist the individual, sick or well, in the performance of those activities contributing to health or its recovery (or to a peaceful death that he would perform unaided if he had the necessary will, strength or knowledge. And to do this in such a way as to help him gain independence as rapidly as possible.”

  10. The synthesis and photocatalytic activity of ZnSe microspheres

    International Nuclear Information System (INIS)

    Cao Huaqiang; Xiao Yujiang; Zhang Sichun

    2011-01-01

    This paper reports the synthesis of semiconductor ZnSe microspheres composed of nanoparticles via a solvothermal route between the organic molecule selenophene (C 4 H 4 Se) and ZnCl 2 without adding any surfactant. The ZnSe microspheres were characterized by x-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), specific surface area measurement, and photoluminescence (PL) spectra. A strong and broad blue PL emission at 443 nm in wavelength (∼2.79 eV in photon energy) is attributed to the near-band-edge (NBE) emission of ZnSe, while the 530 nm peak is a defect-related (DL) emission. The photocatalytic activity of the as-prepared ZnSe microspheres was evaluated by photodegradation of methyl orange (MO) dye under ultraviolet (UV) light and visible light irradiation. The degradations of MO reach 94% or 95.1%, close to 100%, in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 7 or 10 h under UV irradiation, respectively. Meanwhile the degradations of MO reach 94.3% or 60.6% in the presence of the as-synthesized ZnSe microspheres or commercial ZnSe powder after 12 h, respectively. The degradation rate of ZnSe microspheres is twice that of ZnSe commercial powder under UV light irradiation, and three times under visible light irradiation. The degradation process of MO dye on ZnSe microspheres under UV or visible light is also discussed.

  11. Optical studies of CdSe/HgSe and CdSe/Ag2Se core/shell nanoparticles embedded in gelatin

    International Nuclear Information System (INIS)

    Azhniuk, Yu M; Dzhagan, V M; Valakh, M Ya; Raevskaya, A E; Stroyuk, A L; Kuchmiy, S Ya; Zahn, D R T

    2008-01-01

    CdSe/HgSe and CdSe/Ag 2 Se core-shell nanoparticles are obtained by colloidal synthesis from aqueous solutions in the presence of gelatin. Optical absorption, luminescence, and Raman spectra of the nanoparticles obtained are measured. The variation of the optical spectra of CdSe/HgSe and CdSe/Ag 2 Se core-shell nanoparticles with the shell thickness is discussed. Sharp non-monotonous variation of the photoluminescence spectra at low shell coverage is observed.

  12. Structural and optical properties of CdSe nanosheets

    Science.gov (United States)

    Solanki, Rekha Garg; Rajaram, P.; Arora, Aman

    2018-04-01

    Nanosheets of CdSe have been synthesized using a solvothermal route using citric acid as an additive. It is found that the citric acid effectively controls the structural and optical properties of CdSe nanostructures. XRD studies confirm the formation of hexagonal wurtzite phase of CdSe. The FESEM micrographs show that the obtained CdSe nanocrystals are in the form of very thin sheets (nanosheets). Optical absorption studies as well as Photoluminescence spectra show that the optical gap is around 1.76 eV which is close to the reported bulk value of 1.74 eV. The prepared CdSe nanosheets because of large surface area may be useful for catalytic activities in medicine, biotechnology and environmental chemistry and in biomedical imaging for in vitro detection of a breast cancer cells.

  13. Selenium Se and tellurium Te

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for determining selenium and tellurium in various objects are presented. The bichromatometric determination of Te in cadmium, zinc and mercury tellurides is based on oxidation of Te(4) to (6) in H 2 SO 4 with potassium bichromate. In steels, Te is determined photometrically with the aid of KI. The determination is hindered by Fe(3), Cu(2), Bi(3) and Se(4) ions, which must be separated. The extraction-photometric determination of Te in native sulfur is carried out with the aid of 5-mercapto-3-(naphthyl-2)-1,3,4-thiadiazolthione-2 (pH=4.8-5.0). The dyed complex is readily extracted with chloroform and benzene. The spectrophotometric determination of Te in selenium is performed with the aid of 3,5-diphenylpyrazoline-1-dithiocarbamate of sodium. Te is determined in commercial indium, arsenic and their semiconductor compounds photometrically with the aid of copper diethyldithiocarbamate. The method permits determining 5x10 -5 % Te in a weighed amount of 0.5 g. The chloride complex of Te(4) with diantipyriodolpropylmethane is quantitatively extracted with dichloroethane from hydrochloric acid solutions. Thus, any amounts of Te can be separated from Se and determined photometrically. The extraction-photometric determination of Te in commercial lead and bismuth is carried out with the aid of pyrazolone derivatives, in commercial copper with the aid of diantipyridolpropylmethane, and in ores (more than 0.01% Te) with the aid of bismuthol 2. Also described is the extraction-polarographic determination of Te in sulfide ores

  14. Se metallomics during lactic fermentation of Se-enriched yogurt.

    Science.gov (United States)

    Palomo, María; Gutiérrez, Ana M; Pérez-Conde, M Concepción; Cámara, Carmen; Madrid, Yolanda

    2014-12-01

    Selenium biotransformation by lactic acid bacteria during the preparation of Se-enriched yogurt was evaluated. The study focused on the distribution of selenium in the aqueous soluble protein fraction and the detection of selenoamino acids. Screening of selenium in Tris-buffer-urea soluble fraction was carried out by sodium dodecyl sulphate polyacrylamide gel electrophoresis after pre-fractionating with asymmetric field flow fractionation using inductively coupled plasma-mass spectrometry as the detector. Selenium-containing fractions were identified by peptide mapping using nano LC-ESI/LTQMS. Proteins such as thioredoxin, glutaredoxin, albumin, β-lactoglobulin, and lactoperoxidase were identified in the selenium-containing fraction. All these proteins were detected in both the control and the selenium-enriched yogurt except chaperones, which were only detected in the control samples. Chaperones are heat-shock proteins expressed in response to elevated temperature or other cellular stresses. Selenium may have an effect on chaperones expression in Lactobacillus. For the amino acids analysis, selenocysteine was the primary seleno-containing species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Uncertainty aspects of the digital elevation model for the Forsmark area

    Energy Technology Data Exchange (ETDEWEB)

    Stroemgren, Maarten; Brydsten, Lars (Umeaa Univ., Umeaa (Sweden))

    2009-10-15

    A digital elevation model (DEM) describes the terrain relief. A proper DEM is an important data source for many of the different site description models conducted in the Forsmark region. Input data for the Forsmark DEM is elevation data for both land and sea areas of different origin and quality. No statistical analysis of the error in the Forsmark DEM is so far carried out. However, the Forsmark DEM is part of the quality assessment of the regolith depth model for the Forsmark area since it represents the upper surface of the regolith depth model. The aim of this project was to calculate the errors in different areas in the Forsmark DEM and present them in terms of general descriptive statistics. Measurements have confirmed the knowledge that the 0.25-metre DEM produced from the laser scanning measurements in the Laxemar-Simpevarp area is of very high quality. The 0.25-metre DEM was used to calculate the errors of the 10 and 50-metre DEMs, and the errors for different sea shoreline sources. These error distributions were placed randomly among points for the same data sources in the Forsmark area and used for correction of the original elevation levels. Using the corrected input data for the 10 and 50-metre DEMs and for the sea shoreline, a new DEM was produced. All other input data remained unchanged. The error for the Forsmark DEM was calculated for areas within the data sources corrected from the 0.25-metre DEM. The 0.25-metre DEM from the Laxemar-Simpevarp area was also used for a calculation of how density of input data points used in interpolation affects quality in a 20-metre DEM. Part of the input data was removed in the sea area, new DEMs were produced and compared to the existing Forsmark DEM within the areas of the removed data, to get a measure of the error in these areas of the DEM. In areas of input data for the sea shoreline, the quality of the Forsmark DEM is high. The errors within the SKB 10-metre DEM are slightly less than within the extension

  16. Uncertainty aspects of the digital elevation model for the Forsmark area

    International Nuclear Information System (INIS)

    Stroemgren, Maarten; Brydsten, Lars

    2009-10-01

    A digital elevation model (DEM) describes the terrain relief. A proper DEM is an important data source for many of the different site description models conducted in the Forsmark region. Input data for the Forsmark DEM is elevation data for both land and sea areas of different origin and quality. No statistical analysis of the error in the Forsmark DEM is so far carried out. However, the Forsmark DEM is part of the quality assessment of the regolith depth model for the Forsmark area since it represents the upper surface of the regolith depth model. The aim of this project was to calculate the errors in different areas in the Forsmark DEM and present them in terms of general descriptive statistics. Measurements have confirmed the knowledge that the 0.25-metre DEM produced from the laser scanning measurements in the Laxemar-Simpevarp area is of very high quality. The 0.25-metre DEM was used to calculate the errors of the 10 and 50-metre DEMs, and the errors for different sea shoreline sources. These error distributions were placed randomly among points for the same data sources in the Forsmark area and used for correction of the original elevation levels. Using the corrected input data for the 10 and 50-metre DEMs and for the sea shoreline, a new DEM was produced. All other input data remained unchanged. The error for the Forsmark DEM was calculated for areas within the data sources corrected from the 0.25-metre DEM. The 0.25-metre DEM from the Laxemar-Simpevarp area was also used for a calculation of how density of input data points used in interpolation affects quality in a 20-metre DEM. Part of the input data was removed in the sea area, new DEMs were produced and compared to the existing Forsmark DEM within the areas of the removed data, to get a measure of the error in these areas of the DEM. In areas of input data for the sea shoreline, the quality of the Forsmark DEM is high. The errors within the SKB 10-metre DEM are slightly less than within the extension

  17. Phase diagram of the Sb-Se-I system and thermodynamic properties of SbSeI

    International Nuclear Information System (INIS)

    Aliev, Z.S.; Musaeva, S.S.; Babanly, D.M.; Shevelkov, A.V.; Babanly, M.B.

    2010-01-01

    The Sb-Se-I system was investigated by using the DTA and XRD analyses and EMF measurements with an antimony electrode. The T-x diagram of the binary Sb-I system was accurately redefined. A number of polythermal sections and the projection of the liquidus surface were constructed. The fields of the primary crystallization, as well as the types and coordinates of non- and monovariant equilibria were determined. It is shown that the quasi-binary sections Sb 2 Se 3 -SbI 3 , Sb-SbSeI, SbI 3 -Se, and SbSeI-Se triangulate the Sb-Se-I system, leading to five independent subsystems. A broad area of immiscibility, that overlaps a certain part of the antimony primary crystallization field, was found. From the EMF measurements, the partial molar functions of antimony (ΔG-bar, ΔH-bar, ΔS-bar) as well as standard integral thermodynamic functions of SbSeI were calculated. The latter were found to have the following values: ΔG f,298 0 =-80.12±1.81kJ/mol; ΔH f,298 0 =-77.3±1.8kJ/mol; S 298 0 =155.2±9.5J/(molK).

  18. Phase diagram of the Sb-Se-I system and thermodynamic properties of SbSeI

    Energy Technology Data Exchange (ETDEWEB)

    Aliev, Z S; Musaeva, S S; Babanly, D M [Baku State University, General and Inorganic Chemistry Department (Azerbaijan); Shevelkov, A.V., E-mail: shev@inorg.chem.msu.r [Moscow Lomonosov State University, Chemistry Department (Russian Federation); Babanly, M.B., E-mail: Babanly_mb@rambler.r [Baku State University, General and Inorganic Chemistry Department (Azerbaijan)

    2010-09-03

    The Sb-Se-I system was investigated by using the DTA and XRD analyses and EMF measurements with an antimony electrode. The T-x diagram of the binary Sb-I system was accurately redefined. A number of polythermal sections and the projection of the liquidus surface were constructed. The fields of the primary crystallization, as well as the types and coordinates of non- and monovariant equilibria were determined. It is shown that the quasi-binary sections Sb{sub 2}Se{sub 3}-SbI{sub 3}, Sb-SbSeI, SbI{sub 3}-Se, and SbSeI-Se triangulate the Sb-Se-I system, leading to five independent subsystems. A broad area of immiscibility, that overlaps a certain part of the antimony primary crystallization field, was found. From the EMF measurements, the partial molar functions of antimony ({Delta}G-bar, {Delta}H-bar, {Delta}S-bar) as well as standard integral thermodynamic functions of SbSeI were calculated. The latter were found to have the following values: {Delta}G{sub f,298}{sup 0}=-80.12{+-}1.81kJ/mol; {Delta}H{sub f,298}{sup 0}=-77.3{+-}1.8kJ/mol; S{sub 298}{sup 0}=155.2{+-}9.5J/(molK).

  19. Bio-fortification and isotopic labelling of Se metabolites in onions and carrots following foliar application of Se and 77Se

    DEFF Research Database (Denmark)

    Kápolna, Emese; Laursen, Kristian H.; Husted, Søren

    2012-01-01

    Se. The 77Se- labelled metabolites in onions were predominantly γ-glutamyl-77Se-selenomethyl-selenocysteine (γ-glu-Me77SeCys), 77Se-methylselenocysteine (Me77SeCys) and 77Se-selenomethionine (77SeMet). Furthermore, we report here for the first time the finding in carrots of the bioactive Me77SeCys...

  20. PbSe nanocubes obtained by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: hrojasc@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM (Mexico); Achimovicova, M. [Slovak Academy of Sciences, Institute of Geotechnics (Slovakia); Daneu, N. [Jozef Stefan Institute, Department for Nanostructured Materials (Slovenia); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN (Mexico)

    2012-06-15

    In this study, PbSe nanocubes were obtained by high-energy milling, and their optical properties were investigated by measuring the UV-VIS-IR spectra in the range of 200-2,000 nm. The optical absorption of all samples showed a strong UV emission band at 1.45 eV. Previously, to obtain only PbSe nanocubes, an intermediate phase was identified, PbSeO{sub 3}. Although both PbSeO{sub 3} and PbSe were traced through this study, a major effort is devoted to characterize the latter. To trace how chemical transitions evolve from precursors to PbSe, X-ray diffraction and Rietveld refinement were carried out. Therefore, the following parameters were evaluated as a function of milling time: phase percentages, area-to-volume ratio, average crystallite dimensions, specific surface area, and morphology changes. To corroborate previous findings, nitrogen adsorption and transmission electron microscopy techniques were used. All the set experimental results unambiguously confirm that crystallites show a cubic morphology, with its average crystallite size distribution being around 24 nm.

  1. Phase diagram of Se-CaIn4Se7 system

    International Nuclear Information System (INIS)

    Musaeva, R.I.; Aliev, I.I; Ismailova, F.I; Aliev, A.A

    2011-01-01

    Full text: The Se-CaIn 4 Se 7 system has been studied using methods of differential thermal analysis, X-ray diffraction, micro structural analysis, density measurements and its phase diagram has been constructed. It has been established that the section Se-CaIn 4 Se 7 is a quasibinary section of the ternary system Ca-In-Se. At room temperature, on the basis of CaIn 2 Se 4 and Se no solid solution has been found

  2. Variational approach to 68 Se

    International Nuclear Information System (INIS)

    Petrovici, A.; Schmid, K.W.; Faessler, A.; Baktash, C.; Shashi, P.

    1999-01-01

    . Furthermore, our results concerning the pair structure of the wave functions of the even-spin states in chains of even-even and odd-odd N = Z nuclei in the A 60 - 80 mass region revealed a clear interplay between isovector neutron-proton and like-nucleon pairing correlations. Nevertheless, detailed aspects of these properties are sensitive to the renormalization of the effective interaction in the pairing channels. Taking advantage of our microscopic investigations on the coexistence phenomena in this mass region, which have already past many experimental tests, we address the problem of the structure of the lowest few even-spin positive-parity states in 68 Se. Also we present details of the results obtained using a few slightly different prescriptions for the effective interaction in order to illustrate the above mentioned problems. The theoretical spectrum of 68 Se for even spin positive parity states is compared with the experimental results. (authors)

  3. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Socorro County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  4. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Bernalillo County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  5. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Catron County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  6. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Valencia County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  7. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Lincoln County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  8. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for Taos County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  9. Ocean to continent transfer of atmospheric Se as revealed by epiphytic lichens

    International Nuclear Information System (INIS)

    Wen Hanjie; Carignan, Jean

    2009-01-01

    There is still a long-term debate concerning the relative contributions of naturally emitted and anthropogenic Se at the regional and local scales. Here, Se and heavy metal concentrations are reported for epiphytic lichens collected in coastal and inland areas from the USA, Canada and France for assessing atmospheric Se source. Correlations found between Se and Cl in lichens confirmed the major marine biogenic source for atmospheric Se. Continental samples do not show systematic relationships between Se and other metal (Pb, Cu, In ...) contents, even for lichens collected in the vicinity of smelters or close to urban areas. Our results suggest that, although anthropogenic Se may be present, the marine biogenic Se source is a major contributor to atmospheric Se for our sampling locations. The contribution of naturally emitted atmospheric Se may be significant in urban and industrial areas and should be taken into account for further studies. - Although anthropogenic Se may be present, the contribution of naturally emitted atmospheric Se may be significant in urban and industrial areas and should be taken into account for further studies.

  10. The Ag2Se-HgSe-GeSe2 system and crystal structures of the compounds

    International Nuclear Information System (INIS)

    Parasyuk, O.V.; Gulay, L.D.; Romanyuk, Ya.E.; Olekseyuk, I.D.; Piskach, L.V.

    2003-01-01

    The phase diagram of the quasi-ternary Ag 2 Se-HgSe-GeSe 2 system at 298 K was investigated using X-ray phase analysis and metallography. The formation of five intermediate quaternary phases β (Ag ∼7.12-∼6.32 Hg ∼0.44-∼0.82 GeSe 6 ), γ (Ag ∼6.08-∼4.00 Hg ∼0.96-∼2.00 GeSe 6 ), δ (Ag 3.4 Hg 2.3 GeSe 6 ), ε (Ag ∼2.24-∼2.00 Hg ∼2.88-∼3.00 GeSe 6 ) and ∼Ag 1.4 Hg 1.3 GeSe 6 was established. The crystal structure of the β-phase (for the Ag 6.504 Hg 0.912 GeSe 6 composition) was determined using X-ray single crystal diffraction. It crystallizes in a cubic structure (space group F4-bar 3m) with the lattice parameter a=1.09026(4) nm. The crystal structure of the δ-phase (Ag 3.4 Hg 2.3 GeSe 6 ) was determined using X-ray powder diffraction (space group F4-bar 3m, a=1.07767(8) nm). The crystal structure determination of the γ-phase (space group Pmn2 1 ) was performed for the compositions Ag 5.6 Hg 1.2 GeSe 6 , Ag 4.8 Hg 1.6 GeSe 6 and Ag 4 Hg 2 GeSe 6 using X-ray powder diffraction. The crystal structure of the LT-Hg 2 GeSe 4 compound (space group I4-bar , a=0.56786(2), c=1.12579(5) nm) was confirmed by powder diffraction also.

  11. Relação entre solo, vegetação e topografia em área de cerrado (Parque Estadual de Vassununga, SP: como se expressa em mapeamentos? The relationship among soil, vegetation and topography in a cerrado area (Vassununga State Park, SP: how well is it expressed in maps ?

    Directory of Open Access Journals (Sweden)

    Patricia Guidão Cruz Ruggiero

    2006-06-01

    Full Text Available Foram investigadas as relações entre mapas de fitofisionomias, solos e topografia, na Gleba Pé-de-Gigante (21º37'30''S; 47º37'30''W, SP. A área estudada constitui a planície de inundação do córrego Paulicéia e colinas no entorno, onde predominam fisionomias de cerrado, havendo também manchas de floresta estacional, floresta ripária e campo úmido, sobre solos predominantemente arenosos. As cartas temáticas analisadas compreenderam: a mapa pré-existente de fisionomias de vegetação, b mapa hipsométrico, baseado em curvas de nível de 5 em 5 m e c mapa de solos, feito a partir de dados químicos e físicos do solo (amostras coletadas em 54 pontos, nas profundidades: 0-5, 5-25, 40-60 e 80-100 cm e fotografias aéreas (1988, 1:40.000. Os mapas foram re-classificados, para se obter diferentes níveis de detalhamento, e cruzados, em sistema de informação geográfica. Nas tabelas de contingência, geradas a partir dos cruzamentos, foi aplicado o teste de Qui-quadrado e obtido o valor de correlação de Cramér, para investigar a relação entre os mapeamentos. A floresta estacional semidecídua se mostrou fortemente associada à classe geral de Latossolos, e o campo cerrado às altitudes de 620-650 m, provavelmente associado à dinâmica sub-superficial da água. O detalhamento da informação mapeada nos temas analisados não garantiu melhores resultados à interpretação de suas relações, pois as classes fitofisionômicas não respondem diretamente, nem isoladamente, à topografia ou à classificação usual dos solos.Relationships among vegetation, soil and topography maps were investigated in the Pé-de-Gigante Reserve (21º37'30''S; 47º37'30''W, SP. The studied area is the Paulicéia river basin, where soils are predominantly sandy and the vegetation includes a gradient of savanna physiognomies and patches of semideciduous forest, wet fields, and riparian forest. The cartographic material included: a pre-existent vegetation

  12. Clean Energy Solutions Center and SE4All: Partnering to Support Country Actions

    Energy Technology Data Exchange (ETDEWEB)

    2016-05-01

    Since 2012, the Clean Energy Solutions Center (Solutions Center) and Sustainable Energy for All (SE4All) have partnered to deliver information, knowledge and expert assistance to policymakers and practitioners in countries actively working to achieve SE4All objectives. Through SE4All efforts, national governments are implementing integrated country actions to strategically transform their energy markets. This fact sheet details the Solutions Center and SE4All partnership and available areas of technical assistance.

  13. Local structure and defect chemistry of [(SnSe)1.15]m(TaSe2) ferecrystals – A new type of layered intergrowth compound

    International Nuclear Information System (INIS)

    Grosse, Corinna; Atkins, Ryan; Kirmse, Holm; Mogilatenko, Anna; Neumann, Wolfgang; Johnson, David C.

    2013-01-01

    Highlights: •The crystal structure of [(SnSe) 1.15 ] m (TaSe 2 ) ferecrystals was analyzed by TEM. •The layers exhibit turbostratic disorder, but we also observed a local ordering. •The structures of the SnSe and TaSe 2 layers are similar to binary SnSe and 2H-TaSe 2 . •An increasing in-plane SnSe grain size with increasing m was observed. •Defect areas with missing, substituted or additional layers were found. -- Abstract: The atomic structure of the family of ferecrystals [(SnSe) 1.15 ] m (TaSe 2 ) (m = 1, 3, and 6) was investigated by means of transmission electron microscopy. The tantalum in the TaSe 2 layers was observed to have trigonal prismatic coordination similar to that found in the 2H polytype of bulk TaSe 2 . The structure of the SnSe constituent was found to be similar to that of orthorhombic α-SnSe. In the compounds with m = 1 and m = 3, regions with a local ordering of the layers along a commensurate axis, similar to the ordering in conventional misfit layer compounds, were observed. However, on a longer range the ferecrystals were found to exhibit a turbostratically disordered structure. Stacking defects were occasionally found in the samples in which a layer is interrupted and the surrounding layers are bent around these defects, while maintaining abrupt interfaces instead of interdiffusing. Volume defects were found in one sample of [(SnSe) 1.15 ] 1 (TaSe 2 ) 1 in which a SnSe layer locally substitutes a part of a TaSe 2 layer without interrupting the surrounding layers

  14. Capacitors on the basis of intercalate GaSe

    Directory of Open Access Journals (Sweden)

    Kovalyuk Z. D.

    2010-06-01

    Full Text Available The compound GaSe is obtained by the technique of intercalation of a GaSe single crystal in a melt of the ferroelectric salt KNO3. The x-ray analysis of its crystal structure has been carried out and dielectric frequency characteristics of samples has been measured. It is estab-lished, that accumulation of electric charges occurs in the examined examples in frequency area 100—1000 Hz. A sample of filter capacitor has been created on the basis of the re-ceived compounds.

  15. Pulsed laser deposited heterogeneous mixture of Li2Se-Sb2Se3 nanocomposite as a new storage lithium material

    International Nuclear Information System (INIS)

    Yu Le; Chen Jie; Fu Zhengwen

    2010-01-01

    Li 2 Se-Sb 2 Se 3 nanocomposites with a highly heterogeneous mixture have been fabricated by reactive pulsed laser deposition method. The electrochemical properties of the as-deposited Li 2 Se-Sb 2 Se 3 thin film during the first charging and discharging have been investigated by the galvanostatic cycling and cyclic voltammetry measurements for the first time. By using ex situ X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED) measurements, the decomposition of Li 2 Se driven by Sb 2 Se 3 under the electrochemical potential is revealed. In the first cycle, the oxidation peaks at 2.5 V and 3.2 V and the reduction peaks at 2.0 V can be attributed to the decomposition and formation of Li 2 Se with the conversion reaction of Sb 2 Se 3 into Sb 2 Se 5 . Our findings demonstrate that nanocomposite Li 2 Se-Sb 2 Se 3 can possess very high electrochemical activity. These results present a special case of solid-state heterogeneous electrochemistry with both nanostructured binary materials.

  16. Semiconductor-metal transition of Se in Ru-Se Catalyst Nanoparticles

    Science.gov (United States)

    Babu, P. K.; Lewera, Adam; Oldfield, Eric; Wieckowski, Andrzej

    2009-03-01

    Ru-Se composite nanoparticles are promising catalysts for the oxygen reduction reaction (ORR) in fuel cells. Though the role of Se in enhancing the chemical stability of Ru nanoparticles is well established, the microscopic nature of Ru-Se interaction was not clearly understood. We carried out a combined investigation of ^77Se NMR and XPS on Ru-Se nanoparticles and our results indicate that Se, a semiconductor in elemental form, becomes metallic when interacting with Ru. ^77Se spin-lattice relaxation rates are found to be proportional to T, the well-known Korringa behavior characteristic of metals. The NMR results are supported by the XPS binding energy shifts which suggest that a possible Ru->Se charge transfer could be responsible for the semiconductor->metal transition of Se which also makes Ru less susceptible to oxidation during ORR.

  17. One-step synthesis of PbSe-ZnSe composite thin film

    Directory of Open Access Journals (Sweden)

    Abe Seishi

    2011-01-01

    Full Text Available Abstract This study investigates the preparation of PbSe-ZnSe composite thin films by simultaneous hot-wall deposition (HWD from multiple resources. The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films. A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The optical absorption edge of the composite thin films shifts toward the low-photon-energy region as the PbSe content increases. The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

  18. Cs2UPd3Se6

    Directory of Open Access Journals (Sweden)

    George N. Oh

    2011-02-01

    Full Text Available Dicaesium uranium(IV tripalladium(II hexaselenide, Cs2UPd3Se6, crystallizes in the space group Fmmm in the Ba2NaCu3O6 structure type. The asymmetric unit comprises the following atoms with site symmetries as shown: U1 (mm2, Cs1 (222, Cs2 (m2m, Pd1 (.m., Pd2 (2mm, Se1 (m.., and Se2 (1. This layered structure contains six edge-sharing square-planar [PdSe4] units that form a hexagon. These, in turn, edge-share with [USe6] trigonal–prismatic units, forming an extended layer parallel to (010. The layers are stacked along [010]. They are staggered, and are separated by the Cs atoms. The Cs atoms are either coordinated in a square antiprism of Se atoms or are ten-coordinate, with one square face and the opposite face hexagonal.

  19. C-type Nd2Se3

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The title compound, neodymium sesquiselenide, is isotypic with the other known rare-earth metal(III selenides M2Se3 (M = La–Pr and Sm–Lu with the cubic C-type structure. It adopts a cation-defective Th3P4-type arrangement with close to 8/9 of the unique neodymium-cation site occupied, leading to the composition Nd2.667Se4 (Z = 4 or Nd2Se3 (Z = 5.333, respectively. The Nd3+ cations are thus surrounded by eight selenide anions, forming trigonal [NdSe8]13− dodecahedra, whereas the Se2− anions exhibit a sixfold coordination, but due to the under-occupation of neodymium, each one is statistically surrounded by only 5.333 cations. The crystal studied was a merohedral twin with a 0.31 (6:0.69 (6 domain ratio.

  20. Synthesis and characterization of ZnSe:Fe/ZnSe core/shell nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Zhu, Jianguo, E-mail: yanglin_1028@163.com; Xiao, Dingquan

    2014-04-15

    High-quality ZnSe:Fe/ZnSe core/shell nanocrystals were prepared via a hydrothermal microemulsion technique. Effective surface passivation of monodisperse ZnSe:Fe nanocrystals is achieved by overcoating them with a ZnSe shell. The samples were characterized by means of XRD, EDX, TEM, PSD, XPS, photoluminescence, and Raman spectrum. The results show that the as-synthesized nanocrystals are cubic zinc blende ZnSe structure with high purity and the average particle size of ZnSe:Fe/ZnSe core/shell nanocrystal is larger than that of ZnSe:Fe core. The growth of ZnSe shell causes a small red shift in PL spectra, and then the PL quantum yield (QY) increases from 16% before shell growth to the maximum of 37% after increasing shell thickness up to 1.2 monolayers (ML). Moreover, both transverse optic (TO) and longitudinal optic (LO) phonon modes of ZnSe are shifted toward lower frequency as compared with the reported ones. -- Highlights: • ZnSe:Fe/ZnSe core/shell QDs were prepared by a hydrothermal microemulsion method. • ZnSe shell efficiently passivates surface defects by serving as a physical barrier. • The particle size and PL properties can be turned with the growth of ZnSe shell. • The luminescence efficiency and stability of QDs could be improved in this manner.

  1. Freshwater flux to Sermilik Fjord, SE Greenland

    Directory of Open Access Journals (Sweden)

    S. H. Mernild

    2010-10-01

    Full Text Available Terrestrial inputs of freshwater flux to Sermilik Fjord, SE Greenland, were estimated, indicating ice discharge to be the dominant source of freshwater. A freshwater flux of 40.4 ± 4.9×109 m3 y−1 was found (1999–2008, with an 85% contribution originated from ice discharge (65% alone from Helheim Glacier, 11% from terrestrial surface runoff (from melt water and rain, 3% from precipitation at the fjord surface area, and 1% from subglacial geothermal and frictional melting due to basal ice motion. The results demonstrate the dominance of ice discharge as a primary mechanism for delivering freshwater to Sermilik Fjord. Time series of ice discharge for Helheim Glacier, Midgård Glacier, and Fenris Glacier were calculated from satellite-derived average surface velocity, glacier width, and estimated ice thickness, and fluctuations in terrestrial surface freshwater runoff were simulated based on observed meteorological data. These simulations were compared and bias corrected against independent glacier catchment runoff observations. Modeled runoff to Sermilik Fjord was variable, ranging from 2.9 ± 0.4×109 m3 y−1 in 1999 to 5.9 ± 0.9×109 m3 y−1 in 2005. The sub-catchment runoff of the Helheim Glacier region accounted for 25% of the total runoff to Sermilik Fjord. The runoff distribution from the different sub-catchments suggested a strong influence from the spatial variation in glacier coverage, indicating high runoff volumes, where glacier cover was present at low elevations.

  2. EPR of SeO2- and SeO3- radicals in alkaline borate glasses with 77Se isotope

    International Nuclear Information System (INIS)

    Galimov, D.G.; Tarzimanov, K.D.

    1977-01-01

    Alkaline borate glasses with 77 Se were investigated in order to establish the nature of selenium compounds and radicals in glasses. The relationship between alkali ions and the oxygen radical of selenium was determined by decoding the hyperfine structure of the alkaline borate glass EPR spectra obtained before and after γ-irradiation. The irradiated and non-irradiated glasses were characterized by hyperfine splitting of the EPR lines from the α- and β centres. Moreover, the irradiated samples were noted to have a line doublet (signal phi). With intenser reduction conditions of glass fusion, the intensities of α, β, and phi signals were noted to decline. This confirmes the suggestion that these centres were caused by oxygen compouds. The authors concluded that α and β signals were due to the paramagnetic centres of SeO 2 - and [SeO 2 - ]R + , and phi signal to the SeO 3 - radicals

  3. Speciation of Se and DOC in soil solution and their relation to Se bioavailability.

    Science.gov (United States)

    Weng, Liping; Vega, Flora Alonso; Supriatin, Supriatin; Bussink, Wim; Van Riemsdijk, Willem H

    2011-01-01

    A 0.01 M CaCl(2) extraction is often used to asses the bioavailability of plant nutrients in soils. However, almost no correlation was found between selenium (Se) in the soil extraction and Se content in grass. The recently developed anion Donnan membrane technique was used to analyze chemical speciation of Se in the 0.01 M CaCl(2) extractions of grassland soils and fractionation of DOC (dissolved organic carbon). The results show that most of Se (67-86%) in the extractions (15 samples) are colloidal-sized Se. Only 13-34% of extractable Se are selenate, selenite and small organic Se (<1 nm). Colloidal Se is, most likely, Se bound to or incorporated in colloidal-sized organic matter. The dominant form of small Se compounds (selenate, selenite/small organic compounds) depends on soil. A total of 47-85% of DOC is colloidal-sized and 15-53% are small organic molecules (<1 nm). In combination with soluble S (sulfur) and/or P (phosphor), concentration of small DOC can explain most of the variability of Se content in grass. The results indicate that mineralization of organic Se is the most important factor that controls Se availability in soils. Competition with sulfate and phosphate needs to be taken into account. Further research is needed to verify if concentration of small DOC is a good indicator of mineralization of soil organic matter.

  4. On Some Physical Properties of GeSe3-Sb2Se3-ZnSe Thin Films and Their Radiation Response

    International Nuclear Information System (INIS)

    Hosni, H.M.M.A.

    2010-01-01

    Thin films of the chalcogenides GeSe 3 , Sb 2 Se 3 , ZnSe, (GeSe 3 )80(Sb 2 Se 3 )20 and (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20, are prepared by thermal evaporation onto glass substrates. The effect of ZnSe incorporation with both GeSe 3 , Sb 2 Se 3 results in amorphous (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 composition as obtained from the X-ray analysis. Electrical measurements reveal a decrease in dc activation energy, ΔEdc, and an increase in ac activation energy, ΔEac, for (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 as compared with (GeSe 3 )80(Sb 2 Se 3 )20. Optical energy gap, Eg, and band tail width, Ee, are estimated in UV/VIS spectral region for fresh and γ-irradiated films, revealing a decrease in Eg and an increase in Ee for ZnSe and (GeSe 3 )70(Sb 2 Se 3 )10(ZnSe)20 compositions, with irradiation dose.

  5. Excitons, biexcitons, and phonons in ultrathin CdSe/ZnSe quantum structures

    DEFF Research Database (Denmark)

    Gindele, F.; Woggon, Ulrike; Langbein, Wolfgang Werner

    1999-01-01

    The optical properties of CdSe nanostructures grown by migration-enhanced epitaxy of CdSe on ZnSe are studied by time-, energy-, and temperature-dependent photoluminescence and excitation spectroscopy, as well as by polarization-dependent four-wave mixing and two-photon absorption experiments...

  6. Controllable synthesis of metal selenide heterostructures mediated by Ag2Se nanocrystals acting as catalysts

    Science.gov (United States)

    Zhou, Jiangcong; Huang, Feng; Xu, Ju; Wang, Yuansheng

    2013-09-01

    Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe, and even multi-segment heterostructures such as Ag2Se-CdSe-ZnSe and Ag2Se-ZnSe-CdSe, were successfully synthesized. Several interesting features were found in the Ag2Se based heterogrowth. At the initial stage of heterogrowth, a layer of the second phase forms on the surface of an Ag2Se nanosphere, with a curved junction interface between the two phases. With further growth of the second phase, the Ag2Se nanosphere tends to flatten the junction surface by modifying its shape from sphere to hemisphere in order to minimize the conjunct area and thus the interfacial energy. Notably, the crystallographic relationship of the two phases in the heterostructure varies with the lattice parameters of the second phase, in order to reduce the lattice mismatch at the interface. Furthermore, a small lattice mismatch at the interface results in a straight rod-like second phase, while a large lattice mismatch would induce a tortuous product. The reported results may provide a new route for developing novel selenide semiconductor heterostructures which are potentially applicable in optoelectronic, biomedical, photovoltaic and catalytic fields.Ag2Se nanocrystals were demonstrated to be novel semiconductor mediators, or in other word catalysts, for the growth of semiconductor heterostructures in solution. This is a result of the unique feature of Ag2Se as a fast ion conductor, allowing foreign cations to dissolve and then to heterogrow the second phase. Using Ag2Se nanocrystals as catalysts, dimeric metal selenide heterostructures such as Ag2Se-CdSe and Ag2Se-ZnSe

  7. Como Perseu se defendeu de Medusa?

    Directory of Open Access Journals (Sweden)

    Rose Lumertz de Freitas

    2012-04-01

    Full Text Available Na psicanálise francesa, principalmente com Lacan, o conceito de falta passou a ser de grande importância. Ao que, então, perguntamos: o que é a falta? E quando esta falta? O que acontece? O que acontece quando o não especularizável não está excluído, se fazendo, assim, especular? Quando Perseu vai ao encontro de Medusa, guiando-se por sua imagem refletida em um espelho de bronze polido, segurado por Atena, como pôde este herói defender-se de Medusa? Qual foi a forma encontrada por ele para se defender da presença do objeto que introduz a dimensão do real nu?

  8. Solving the shape conundrum in $^{70}$Se

    CERN Multimedia

    We propose a multi-step Coulomb-excitation study of $^{70}$Se at HIE-ISOLDE using the $^{208}$Pb( $^{70}$Se, $^{70}$Se*)$^{208}$Pb* reaction at a safe energy of 5.0 MeV/u. We aim at a precise measurement of the $\\left \\langle 2^{+}_{1} \\hspace{0.1cm} || \\hspace{0.1cm}\\hat{E}2 \\hspace{0.1cm} || \\hspace{0.1cm}2^{+}_{ 1} \\right \\rangle$ diagonal matrix element as well as gaining information on additional matrix elements. Such information will shed light onto the shape conundrum of the 2$^{+}_{1}$ state in $^{70}$Se as well as foreseeing the opportunity for a more detailed understanding of the shape-coexistence phenomenon in this region.

  9. Thermoelectric prospects of chemically deposited PbSe and SnSe thin films

    Science.gov (United States)

    Nair, P. K.; Martínez, Ana Karen; Rosa García Angelmo, Ana; Barrios Salgado, Enue; Nair, M. T. S.

    2018-03-01

    Thin films of PbSe of 400-600 nm in thickness, were obtained via chemical deposition from a solution containing lead nitrate, thiourea and selenosufate. SnSe thin films of 90-180 nm in thickness, were also obtained by chemical deposition from a solution containing selenosulfate. Optical and electrical properties of these thin films were significantly altered by heating them in selenium vapor at 300 °C. Thin film PbSe has a bandgap (Eg) of 1.17 eV (direct gap, forbidden transitions), which decreases to 0.77 eV when it has been heated. Its electrical conductivity (σ) is p-type: 0.18 Ω-1 cm-1 (as-prepared), and 6.4 Ω-1 cm-1 when heated. Thin film SnSe is of orthorhombic crystalline structure which remains stable when heated at 300 °C, but its Eg increases from 1.12 eV (indirect) in as-prepared film to 1.5 eV (direct, forbidden transitions) upon heating. Its electrical conductivity is p-type, which increases from 0.3 Ω-1 cm-1 (as-prepared) to 1 Ω-1 cm-1 when heated (without Se-vapor). When SnSe film is heated at 300 °C in the presence of Se-vapor, they transform to SnSe2, with Eg of 1.5 eV (direct, forbidden) with n-type electrical conductivity, 11 Ω-1 cm-1. The Seebeck coefficient for the PbSe films is: +0.55 mV K-1 (as prepared) and +0.275 mV K-1 (heated); for SnSe films it is: +0.3 mV K-1 (as prepared) and +0.20 mV K-1 (heated); and for SnSe2 film, - 0.35 mV K-1. A five-element PbSe-SnSe2-PbSe-SnSe2-PbSe thermoelectric device demonstrated 50 mV for a temperature difference ΔT = 20 °C (2.5 mV K-1). For SnSe-SnSe2-SnSe-SnSe2-SnSe device, the value is 15 mV for ΔT = 20 °C (0.75 mV K-1). Prospect of these thin films in thermoelectric devices of hybrid materials, in which the coatings may be applied on distinct substrate and geometries is attractive.

  10. Lustre filesystem for CMS storage element (SE)

    International Nuclear Information System (INIS)

    Wu, Y; Kim, B; Avery, P; Fu, Y; Bourilkov, D; Taylor, C; Prescott, C; Rodriguez, J

    2011-01-01

    This paper presents our effort to integrate the Lustre filesystem with BeStMan, GridFTP and Ganglia to make it a fully functional WLCG SE (Storage Element). We first describe the configuration of our Lustre filesystem at the University of Florida and our integration process. We then present benchmark performance figures and IO rates from the CMS analysis jobs and the WAN data transfer performance that are conducted on the Lustre SE.

  11. The system SnTe-InSe

    International Nuclear Information System (INIS)

    Gurshumov, A.P.; Alidzhanov, M.A.; Aliev, A.S.; Gadzhiev, T.G.; Mamedov, N.A.

    1986-01-01

    This paper discusses the nature of the interaction and physicochemical properties of the alloys of the system SnTe-InSe. The DTA was performed on an NTR-74 pyrometer, XPA on a Dron-2.0 diffractometer and MSA on an MIM-7 metallographic microscope. The microhardness of the samples was determined on a PMT-3 microhardness tester. The congruently melting compound SnInTeSe and solid solutions based on the starting components are formed in the system

  12. Los jóvenes se incomunican

    Directory of Open Access Journals (Sweden)

    Margarita Ferro

    2015-01-01

    Full Text Available Hace años los jóvenes se comunicaban y relacionaban con sus amigos del barrio o de la escuela por lo que desde pequeños desarrollaban una comunicación interpersonal fluida. Hoy los video-juegos han sustituido la amistad y se han transformado en elementos de la comunicación. La autora analiza el mundo del nintendo y su influencia en las personas

  13. Control Areas

    Data.gov (United States)

    Department of Homeland Security — This feature class represents electric power Control Areas. Control Areas, also known as Balancing Authority Areas, are controlled by Balancing Authorities, who are...

  14. The determination of Se content in Se egg by NAA in MNSR

    International Nuclear Information System (INIS)

    Wang Ke; Hou Xiaolin

    1994-01-01

    The selenium contents in the yolk, albumin and shell of the egg which was laid by layer hen fed with various Se concentrations are determined by thermal neutron activation analysis with a nuclear reaction 78 Se(n, γ) 77 Se m on the miniature neutron source reactor (MNSR). The results show that the more the selenium added to the feed, the higher the Se content in the egg and that in the egg constituents, the highest Se content is in the egg yolk and the lowest in the egg albumin

  15. Thermoelectric transport of Se-rich Ag2Se in normal phases and phase transitions

    International Nuclear Information System (INIS)

    Mi, Wenlong; Lv, Yanhong; Qiu, Pengfei; Shi, Xun; Chen, Lidong; Zhang, Tiansong

    2014-01-01

    Small amount of Se atoms are used to tune the carrier concentrations (n H ) and electrical transport in Ag 2 Se. Significant enhancements in power factor and thermoelectric figure of merit (zT) are observed in the compositions of Ag 2 Se 1.06 and Ag 2 Se 1.08 . The excessive Se atoms do not change the intrinsically electron-conducting character in Ag 2 Se. The detailed analysis reveals the experiment optimum carrier concentration in Ag 2 Se is around 5 × 10 18  cm −3 . We also investigate the temperature of maximum zT and the thermoelectric transport during the first order phase transitions using the recently developed measurement system

  16. Measurement of 76Se and 78Se (γ, n) cross sections

    International Nuclear Information System (INIS)

    Kitatani, Fumito; Harada, Hideo; Goko, Shinji; Utsunomiya, Hiroaki; Akimune, Hidetoshi; Toyokawa, Hiroyuki; Yamada, Kawakatsu

    2011-01-01

    The (γ, n) cross sections of Se isotopes ( 76 Se, 78 Se) were measured to supply fundamental data for estimating the inverse reaction cross section, i.e., the 79 Se(n, γ) 80 Se cross section. The enriched samples and a reference 197 Au sample were irradiated with laser-Compton scattering (LCS) γ-rays. The excitation function of each (γ, n) cross section was determined for the energy range from each near neutron separation energy to the threshold energy of (γ, 2n) reaction. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS γ-rays. Systematic (γ, n) cross sections for Se isotopes including 80 Se were compared with those calculated by using a statistical model calculation code TALYS. (author)

  17. Hopping conduction in gamma-irradiated InSe and InSe:Sn single crystals

    International Nuclear Information System (INIS)

    MUSTAFAEVA, S.N.; ISMAILOV, A.A.; ASADOV, M.M.

    2010-01-01

    Full text : The semiconductive InSe layer compound is characterized by a strong covalent bond inside the layers and a weak Van der Waals bonding between them. It was shown that across the layers of InSe single crystals at low temperatures (T ≤ 200 K) at direct current (dc) hopping conduction through localized states near the Fermi level takes place. The results of dc-conductivity of gamma-irradiated p-InSe and n-InSe : Sn layer single crystals have been presented in this work. ρ-InSe single crystal specimens grown by the Bridgman method were used in the experiments. Plates of the crystals under study were obtained by cleaving along the layers of single crystal ingots. The single-crystal InSe samples for electric measurements had the form of planar capacitors normal to the C axis of the crystals, with silver-paste electrodes. The thickness of the InSe samples was 300 mkm. Co 60 serves as the source of irradiation with energy of gamma-quantum equal to 1.3 MeV. The electric properties of non-irradiated and gamma-irradiated InSe crystals were measured under the same conditions. It is revealed that InSe and InSe : Sn (0.2 and 0.4 mole percent Sn) single crystals exhibit a variable range hopping conduction along a normal to their natural layers at temperatures T≤200 K in a dc electric field. From experimental data the parameters of localized states of p-InSe and n-InSe : Sn were calculated before and after gamma-irradiation. It is revealed that gamma-irradiation of p-InSe and n-InSe : Sn (0.2 and 0.4 mole percent Sn) single crystals leads to significant change of localized states parameters. After gamma-irradiation the density of states near the Fermi level increased, but their energy spread and the average jump distance decreased. The concentrations of radiated defects were estimated in p-InSe (5.18*10 1 7 sm - 3) and n-InSe : Sn (2.5*10 1 7 - 2.7*10 1 8 sm - 3) single crystals. The present results demonstrate that gamma-irradiation offers the possibility of tuning

  18. ¿ Como se hace una Telenovela ?

    Directory of Open Access Journals (Sweden)

    Iván Gavaldón

    2015-01-01

    Full Text Available La autora relata la historia de las Relaciones Públicas y dice que surgieron y se desarrollaron para legitimar ante el público los intereses económicos y políticos de quienes detentan el poder. Se cuestiona sobre el por qué no aplicar las relaciones públicas, en organizaciones populares, para que mejoren su publicación y orienten sus propósitos de desarrollo. El tema que aborda las Políticas culturales en América Latina acopia un extracto de lo más trascendente de los ensayos del libro editado por Néstor García Canclini. Sobre la telenovela se afirma que esta ha llegado a ser uno de los instrumentos más importantes de la comunicación popular: por ella desfilan las identidades de las más variadas culturas brasileñas. Y en cuanto a la caricatura se relata lo que ocurrió en el Seminario taller " Caricatura y Periodismo", realizado el(9-11 de Nov.- 1987 en el CIESPAL. El estudio sobre el mercado del vídeo se ve dificultado por la imprecisión de los datos obtenidos. Los datos oficiales no siempre se aproximan a la realidad, pues el mercado de vídeo se instauró en América Latina partiendo de una lógica totalmente diversa de los equipos de sonido e imagen.

  19. PbSe Nanocrystal Excitonic Solar Cells

    KAUST Repository

    Choi, Joshua J.

    2009-11-11

    We report the design, fabrication, and characterization of colloidal PbSe nanocrystal (NC)-based photovoltaic test structures that exhibit an excitonic solar cell mechanism. Charge extraction from the NC active layer is driven by a photoinduced chemical potential energy gradient at the nanostructured heterojunction. By minimizing perturbation to PbSe NC energy levels and thereby gaining insight into the "intrinsic" photovoltaic properties and charge transfer mechanism of PbSe NC, we show a direct correlation between interfacial energy level offsets and photovoltaic device performance. Size dependent PbSe NC energy levels were determined by cyclic voltammetry and optical spectroscopy and correlated to photovoltaic measurements. Photovoltaic test structures were fabricated from PbSe NC films sandwiched between layers of ZnO nanoparticles and PEDOT:PSS as electron and hole transporting elements, respectively. The device current-voltage characteristics suggest a charge separation mechanism that Is distinct from previously reported Schottky devices and consistent with signatures of excitonic solar cells. Remarkably, despite the limitation of planar junction structure, and without film thickness optimization, the best performing device shows a 1-sun power conversion efficiency of 3.4%, ranking among the highest performing NC-based solar cells reported to date. © 2009 American Chemical Society.

  20. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    Science.gov (United States)

    Fan, Zhaochuan; Koster, Rik S.; Wang, Shuaiwei; Fang, Changming; Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W.; van Huis, Marijn A.; Vlugt, Thijs J. H.

    2014-12-01

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., "Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth," Nano Lett. 14, 3661-3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

  1. A transferable force field for CdS-CdSe-PbS-PbSe solid systems

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhaochuan; Vlugt, Thijs J. H., E-mail: t.j.h.vlugt@tudelft.nl [Process and Energy Department, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft,The Netherlands (Netherlands); Koster, Rik S.; Fang, Changming; Huis, Marijn A. van [Debye Institute for Nanomaterials Science and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht (Netherlands); Wang, Shuaiwei [Institute of Nanostructured Functional Materials, Huanghe Science and Technology College, Zhengzhou, Henan 450006 (China); Yalcin, Anil O.; Tichelaar, Frans D.; Zandbergen, Henny W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

    2014-12-28

    A transferable force field for the PbSe-CdSe solid system using the partially charged rigid ion model has been successfully developed and was used to study the cation exchange in PbSe-CdSe heteronanocrystals [A. O. Yalcin et al., “Atomic resolution monitoring of cation exchange in CdSe-PbSe heteronanocrystals during epitaxial solid-solid-vapor growth,” Nano Lett. 14, 3661–3667 (2014)]. In this work, we extend this force field by including another two important binary semiconductors, PbS and CdS, and provide detailed information on the validation of this force field. The parameterization combines Bader charge analysis, empirical fitting, and ab initio energy surface fitting. When compared with experimental data and density functional theory calculations, it is shown that a wide range of physical properties of bulk PbS, PbSe, CdS, CdSe, and their mixed phases can be accurately reproduced using this force field. The choice of functional forms and parameterization strategy is demonstrated to be rational and effective. This transferable force field can be used in various studies on II-VI and IV-VI semiconductor materials consisting of CdS, CdSe, PbS, and PbSe. Here, we demonstrate the applicability of the force field model by molecular dynamics simulations whereby transformations are initiated by cation exchange.

  2. 4-CM2 CuInGaSe2 based solar cells

    International Nuclear Information System (INIS)

    Devaney, W.E.; Stewart, J.M.; Chen, W.S.

    1990-01-01

    This paper reports that polycrystalline thin-film solar cells with the structure ZnO/CdZnS/CuInGaSe 2 have been fabricated with larger single cell areas than have been previously reported. A cell of area 4-cm 2 has been made with an Am1.5, 100 mW/cm 2 total area conversion efficiency of (11.1% 912.0% active area) and AMO conversion efficiency of 10.0% (10.9% active area). The CuInGaSe 2 layer had a gallium to indium ratio of 0.26:0.74 with a band gap of approximately 1.15 eV. The cells use an isolated tab design for the negative (grid) contact, demonstrating the ability to pattern the semiconductor layers. Such CuInGaSe 2 based cells may be suitable both for large area terrestrial applications and for single-junction space cell applications

  3. Lattice thermal conductivity of LaSe

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei, E-mail: tolwwt@163.com [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Pan, Zhong-liang; Chen, Jun-fang; He, Qin-yu [School of Physics and Telecommunication Engineering, South China Normal University, 510006 Guangzhou (China); Wang, Teng [School of Computer, South China Normal University, 510631 Guangzhou (China)

    2015-07-15

    The phonon dispersions and phonon density of states of LaSe are obtained, based on density functional perturbation theory and the norm-conserving pseudo-potential method. An anomaly in calculated phonon dispersion curves is presented and interpreted as a Kohn anomaly. The heat capacity of LaSe is calculated then. For the three-phonon process scattering, the lowest non-harmonic cubic terms of the interatomic potential are considered to obtain single-phonon relaxation rate by applying the Fermi's golden rule. For the boundary scattering, the average phonon relaxation time was obtained. Considering two kinds of phonon scattering mechanisms, we obtain the lattice thermal conductivity of LaSe.

  4. Improved photoluminescence quantum yield and stability of CdSe-TOP, CdSe-ODA-TOPO, CdSe/CdS and CdSe/EP nanocomposites

    Science.gov (United States)

    Wei, Shutian; Zhu, Zhilin; Wang, Zhixiao; Wei, Gugangfen; Wang, Pingjian; Li, Hai; Hua, Zhen; Lin, Zhonghai

    2016-07-01

    Size-controllable monodisperse CdSe nanocrystals with different organic capping were prepared based on the hot-injection method. The effective separation of nucleation and growth was achieved by rapidly mixing two highly reactive precursors. As a contrast, we prepared CdSe/CdS nanocrystals (NCs) successfully based on the selective ion layer adsorption and reaction (SILAR) technique. This inorganic capping obtained higher photoluminescence quantum yield (PLQY) of 59.3% compared with organic capping of 40.8%. Furthermore, the CdSe-epoxy resin (EP) composites were prepared by adopting a flexible ex situ method, and showed excellent stability in the ambient environment for one year. So the composites with both high PLQY of nanocrystals and excellent stability are very promising to device application.

  5. Preliminary site description Forsmark area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, Kristina [ed.

    2005-06-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterisation at two different locations, the Forsmark and Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. An integrated component in the characterisation work is the development of a site descriptive model that constitutes a description of the site and its regional setting, covering the current state of the geosphere and the biosphere as well as those ongoing natural processes that affect their long-term evolution. The present report documents the site descriptive modelling activities (version 1.2) for the Forsmark area. The overall objectives of the version 1.2 site descriptive modelling are to produce and document an integrated description of the site and its regional environments based on the site-specific data available from the initial site investigations and to give recommendations on continued investigations. The modelling work is based on primary data, i.e. quality-assured, geoscientific and ecological field data available in the SKB databases SICADA and GIS, available July 31, 2004. The work has been conducted by a project group and associated discipline-specific working groups. The members of the project group represent the disciplines of geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry, transport properties and surface ecosystems (including overburden, surface hydrogeochemistry and hydrology). In addition, some group members have specific qualifications of importance in this type of project e.g. expertise in RVS (Rock Visualisation System) modelling, GIS-modelling and in statistical data analysis. The overall strategy to achieve a site description is to develop discipline-specific models by interpretation and analyses of the primary data. The different discipline-specific models are then integrated into a site description. Methodologies for developing the discipline-specific models are documented in

  6. Preliminary site description Forsmark area - version 1.2

    International Nuclear Information System (INIS)

    Skagius, Kristina

    2005-06-01

    The Swedish Nuclear Fuel and Waste Management Company (SKB) is undertaking site characterisation at two different locations, the Forsmark and Simpevarp areas, with the objective of siting a geological repository for spent nuclear fuel. An integrated component in the characterisation work is the development of a site descriptive model that constitutes a description of the site and its regional setting, covering the current state of the geosphere and the biosphere as well as those ongoing natural processes that affect their long-term evolution. The present report documents the site descriptive modelling activities (version 1.2) for the Forsmark area. The overall objectives of the version 1.2 site descriptive modelling are to produce and document an integrated description of the site and its regional environments based on the site-specific data available from the initial site investigations and to give recommendations on continued investigations. The modelling work is based on primary data, i.e. quality-assured, geoscientific and ecological field data available in the SKB databases SICADA and GIS, available July 31, 2004. The work has been conducted by a project group and associated discipline-specific working groups. The members of the project group represent the disciplines of geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry, transport properties and surface ecosystems (including overburden, surface hydrogeochemistry and hydrology). In addition, some group members have specific qualifications of importance in this type of project e.g. expertise in RVS (Rock Visualisation System) modelling, GIS-modelling and in statistical data analysis. The overall strategy to achieve a site description is to develop discipline-specific models by interpretation and analyses of the primary data. The different discipline-specific models are then integrated into a site description. Methodologies for developing the discipline-specific models are documented in

  7. Static structure of superionic conducting glass of Ag-Ge-Se system

    Energy Technology Data Exchange (ETDEWEB)

    Suenaga, R; Nakashima, S; Tahara, S; Takeda, S [Graduate School of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Fukuoka 810-8560 (Japan); Kawakita, Y [Faculty of Sciences, Kyushu University, 4-2-1 Ropponmatsu, Fukuoka 810-8560 (Japan); Kohara, S [Japan Synchrotron Radiation Research Inst., 1-1-1 Kouto, Sayo-cho, Hyogo 679-5198 (Japan)], E-mail: takeda@rc.kyushu-u.ac.jp

    2008-02-15

    Superionic conducting glasses are the important materials as solid electrolytes. Amorphous Ag-Ge-Se system is well known to exhibit the superionic conducting behavior where silver ions easily migrate into the mixed structure of Ag{sub 2}Se and Ge-Se chalcogenide glass. It will be good material to study how the superionic conducting region distributes in the glassy network, and whether the conducting paths extends to the entire of the material, or the localized and limited area in an isolated region. In this paper, we will present the results of the static structure of Ag-Ge-Se system by high-energy X-ray diffraction measurements.

  8. Luminescence spectra of CdSe/ZnSe double layers of quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Reznitsky, Alexander; Permogorov, Sergei; Korenev, Vladimir V.; Sedova, Irina; Sorokin, Sergey; Sitnikova, Alla; Ivanov, Sergei [A.F. Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, 194021 St. Petersburg (Russian Federation); Klochikhin, Albert [B.P. Konstantinov Nuclear Physics Institute, St. Petersburg (Russian Federation)

    2009-12-15

    We have studied the emission spectra and structural properties of double CdSe/ZnSe quantum dot (QD) sheet structures grown by molecular beam epitaxy in order to elucidate the mechanisms of the electronic and strain field interaction between the QD planes. The thickness of the ZnSe barrier separating the CdSe sheets was in the range of 10-60 monolayers (ML) in the set of samples studied. We have found that coupling between dots in adjacent layers becomes relatively strong in CdSe/ZnSe double layers structures with 25-27 ML barrier, while it is rather weak when the barrier thickness exceeds 30 ML. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. One-pot synthesis of hollow NiSe-CoSe nanoparticles with improved performance for hybrid supercapacitors

    Science.gov (United States)

    Chen, Haichao; Fan, Meiqiang; Li, Chao; Tian, Guanglei; Lv, Chunju; Chen, Da; Shu, Kangying; Jiang, Jianjun

    2016-10-01

    Hollow NiSe-CoSe samples have been synthesized for the first time via a one-pot solvothermal approach. The strategy is robust enough to synthesize NiSe-CoSe nanoparticles with different NiSe to CoSe ratios but with a similar hollow structure. Co ions in the NiSe-CoSe nanoparticles play decisive role for formation of the hollow structure; otherwise, the nanoparticles become solid for the NiSe sample. When used as the positive electroactive materials for energy storage, the NiSe-CoSe samples show excellent electrochemical activity in alkaline electrolyte. Using the synergistic effect between NiSe and CoSe, the electrochemical performance of NiSe-CoSe can be tuned by varying the NiSe to CoSe ratios. The NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 shows the best electrochemical performance in terms of superior specific capacity, improved rate capability and excellent cycling stability. In addition, the electrochemical performance of NiSe-CoSe sample with a NiSe to CoSe ratio of 4:2 is also evaluated via assembling hybrid supercapacitors with RGO, and the hybrid supercapacitor delivers both high power and energy densities (41.8 Wh kg-1 at 750 W kg-1 and 20.3 Wh kg-1 at 30 kW kg-1).

  10. Histotopography of the radiopharmaceuticals 75Se-selenomethionine and 75Se-selenite in critical organs of adult and embryonic mice

    International Nuclear Information System (INIS)

    Khant, S.E.; Norets, T.A.

    1981-01-01

    Adult male and pregnant mice received 75 Se-labelled methionine and selenite, resp. The critical organs and the embryos were examined histoautoradiographically at different time intervals as to the organ distribution of the radiopharmaceuticals. All organs revealed a heterogeneity of the 75 Se distribution with an intensity being unequally organo-specific and depending on the type of the radiopharmaceutical. 75 Se-selenomethionine was deposited mainly in functional areas of kidneys, liver, bone marrow and testes thus causing a long-term retention and an intensive irradiation of these organs. In the embryos 75 Se-seleno-methionine was distributed unequally preferring liver, hematopoietic areas of the bone marrow and the lens

  11. Synthesis and properties of new CdSe-AgI-As2Se3 chalcogenide glasses

    International Nuclear Information System (INIS)

    Kassem, M.; Le Coq, D.; Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E.

    2011-01-01

    Research highlights: → Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As 2 Se 3 system. → Characterization of macroscopic properties of the new CdSe-AgI-As 2 Se 3 glasses. → Far infrared transmission of chalcogenide glasses. → Characterization of the total conductivity of CdSe-AgI-As 2 Se 3 glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As 2 Se 3 system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T g ), crystallisation (T x ), and melting (T m ) temperatures are reported and used to calculate their ΔT = T x - T g and their Hruby, H r = (T x - T g )/(T m - T x ), criteria. Evolution of the total electrical conductivity σ and the room temperature conductivity σ 298 was also studied. The terahertz transparency domain in the 50-600 cm -1 region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  12. No todo lo que cuenta se cuenta

    NARCIS (Netherlands)

    van Rijckevorsel, J.

    2008-01-01

    En este trabajo publicado en "Insurance Economics" Nº 58 (Julio 2008), Jan van Rijckevorsel hace un profundo análisis del uso práctico de las estadísticas de seguros aplicadas a aspectos reales del quehacer institucional del sector, y señala varios campos (como el valor y calificación de la

  13. Properties and Bibliography of GaSe

    Science.gov (United States)

    1994-02-01

    Musaev, A. E. Bakhyshev, N. M. Gasanly and L. G. Musaeva . (1975). "Anisotropy of the optical constants of GaS and GaSe near the absorption edge." Sov...Phys. Semiconductors. 9 94-95 Russian ref.: Fiz. Tekh. Poluprovodn. 9 142-145 (January 1975). Akhundov, G. A., L. G. Musaeva and M. D. Khomutova

  14. VerSeDa: vertebrate secretome database.

    Science.gov (United States)

    Cortazar, Ana R; Oguiza, José A; Aransay, Ana M; Lavín, José L

    2017-01-01

    Based on the current tools, de novo secretome (full set of proteins secreted by an organism) prediction is a time consuming bioinformatic task that requires a multifactorial analysis in order to obtain reliable in silico predictions. Hence, to accelerate this process and offer researchers a reliable repository where secretome information can be obtained for vertebrates and model organisms, we have developed VerSeDa (Vertebrate Secretome Database). This freely available database stores information about proteins that are predicted to be secreted through the classical and non-classical mechanisms, for the wide range of vertebrate species deposited at the NCBI, UCSC and ENSEMBL sites. To our knowledge, VerSeDa is the only state-of-the-art database designed to store secretome data from multiple vertebrate genomes, thus, saving an important amount of time spent in the prediction of protein features that can be retrieved from this repository directly. VerSeDa is freely available at http://genomics.cicbiogune.es/VerSeDa/index.php. © The Author(s) 2017. Published by Oxford University Press.

  15. Det faderløse samfund

    DEFF Research Database (Denmark)

    Jensen, Henrik

    Det faderløse samfund er en kulturhistorisk afdækning af fader- og autoritetstabet i det 20. århundredes Europa, med fokus på fader-søn-forholdet og fortalt gennem skikkelser som Max Weber, Freud, Jung, Kafka - og ’den uregerlige søn’ over dem alle, psykologen og anarkisten Otto Gross. Den er...

  16. Señales en el agua

    Directory of Open Access Journals (Sweden)

    Helcías Martan Góngora

    1964-11-01

    Full Text Available La lluvia fue siempre compañera de la soledad. En su ámbito de música se mueve el pensamiento con monótono ritmo y el alma encuentra su centro de gravedad, mientras dura el imperio de su amada caricia.

  17. Femtosecond Laser-Induced Formation of Wurtzite Phase ZnSe Nanoparticles in Air

    Directory of Open Access Journals (Sweden)

    Hsuan I Wang

    2012-01-01

    Full Text Available We demonstrate an effective method to prepare wurtzite phase ZnSe nanoparticles from zincblende ZnSe single crystal using femtosecond pulse laser ablation. The fabricated ZnSe nanoparticles are in spherical shape and uncontaminated while synthesized under ambient environment. By controlling the laser fluences, the average size of ZnSe nanoparticles can be varied from ~16 nm to ~22 nm in diameter. In Raman spectra, the surface phonon mode becomes dominant in the smaller average particle size with uniform size distribution. The interesting phase transition from the zinc blende structure of ZnSe single crystal to wurtzite structure of ZnSe nanoparticles may have been induced by the ultrahigh ablation pressure at the local area due to the sudden injection of high energy leading to solid-solid transition.

  18. Flexible, High-Speed CdSe Nanocrystal Integrated Circuits.

    Science.gov (United States)

    Stinner, F Scott; Lai, Yuming; Straus, Daniel B; Diroll, Benjamin T; Kim, David K; Murray, Christopher B; Kagan, Cherie R

    2015-10-14

    We report large-area, flexible, high-speed analog and digital colloidal CdSe nanocrystal integrated circuits operating at low voltages. Using photolithography and a newly developed process to fabricate vertical interconnect access holes, we scale down device dimensions, reducing parasitic capacitances and increasing the frequency of circuit operation, and scale up device fabrication over 4 in. flexible substrates. We demonstrate amplifiers with ∼7 kHz bandwidth, ring oscillators with <10 μs stage delays, and NAND and NOR logic gates.

  19. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb; Singh, Nirpendra; Schwingenschlö gl, Udo

    2015-01-01

    The structural and optical properties of the chalcopyrite CunGanSe2n and CunInnSe2n nanoclusters (n = 2, 4, 6, and 8) are investigated as a function of the size using a combination of basin-hopping global optimization and time-dependent density

  20. Theoretical and experimental studies of the ZnSe/CuInSe2 heterojunction band offset

    International Nuclear Information System (INIS)

    Nelson, A.J.; Schwerdtfeger, C.R.; Wei, S.; Zunger, A.; Rioux, D.; Patel, R.; Hoechst, H.

    1993-01-01

    We report first-principles band structure calculations that show that ZnSe/CuInSe 2 has a significant valence band offset (VBO, ΔE v ): 0.70±0.05 eV for the relaxed interface and 0.60±0.05 eV for the coherent interface. These large values demonstrate the failure of the common anion rule. This is traced to a stronger Cu,d-Se,p level repulsion in CuInSe 2 than the Zn,d-Se,p repulsion in ZnSe. The VBO was then studied by synchrotron radiation soft x-ray photoemission spectroscopy. ZnSe overlayers were sequentially grown in steps on n-type CuInSe 2 (112) single crystals at 200 degree C. In situ photoemission measurements were acquired after each growth in order to observe changes in the valence band electronic structure as well as changes in the In 4d and Zn 3d core lines. Results of these measurements reveal that the VBO is ΔE v =0.70±0.15 eV, in good agreement with the first-principles prediction

  1. Que se vea lo que se oye: a vueltas con los fonemas y las letras

    Directory of Open Access Journals (Sweden)

    Gómez del Estal Villarino, Mario

    2011-03-01

    Full Text Available Partiendo de lo que el refrán “La letra con sangre entra” viene a decir a quien se deje escucharlo, se abre una descripción de las diferencias radicales que se dan entre aprender a hablar y aprender a escribir. La relación entre ambas actividades no se puede entender sin analizar la tan extendida perversión que supone hablar lo que se escribe en vez de escribir lo que se habla. A continuación, se detallan algunos de los síntomas más frecuentes de dicha perversión, caracterizados todos por la intromisión de la conciencia en terrenos donde lo único que hace es estorbar, en especial la pronunciación pedantesca de ciertos finales silábicos o de palabra, como en traNSporte, aBStraKción, óPtico, oBjeto, fúTbol, libertaD, diGno o fraK, así como las distintas deformaciones que sufren las palabras que la ortografía académica prescribe que se escriban con la letra equis.

  2. Exciton dephasing and biexciton binding in CdSe/ZnSe islands

    DEFF Research Database (Denmark)

    Wagner, Hans Peter; Tranitz, H.-P.; Preis, H

    1999-01-01

    The dephasing of excitons and the formation of biexcitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of exciton-exciton scattering efficiencies and dephasing times in the range of 0.5-10 ps...

  3. Anisotropy in CdSe quantum rods

    Energy Technology Data Exchange (ETDEWEB)

    Li, Liang-shi [Univ. of California, Berkeley, CA (United States)

    2003-01-01

    The size-dependent optical and electronic properties of semiconductor nanocrystals have drawn much attention in the past decade, and have been very well understood for spherical ones. The advent of the synthetic methods to make rod-like CdSe nanocrystals with wurtzite structure has offered us a new opportunity to study their properties as functions of their shape. This dissertation includes three main parts: synthesis of CdSe nanorods with tightly controlled widths and lengths, their optical and dielectric properties, and their large-scale assembly, all of which are either directly or indirectly caused by the uniaxial crystallographic structure of wurtzite CdSe. The hexagonal wurtzite structure is believed to be the primary reason for the growth of CdSe nanorods. It represents itself in the kinetic stabilization of the rod-like particles over the spherical ones in the presence of phosphonic acids. By varying the composition of the surfactant mixture used for synthesis we have achieved tight control of the widths and lengths of the nanorods. The synthesis of monodisperse CdSe nanorods enables us to systematically study their size-dependent properties. For example, room temperature single particle fluorescence spectroscopy has shown that nanorods emit linearly polarized photoluminescence. Theoretical calculations have shown that it is due to the crossing between the two highest occupied electronic levels with increasing aspect ratio. We also measured the permanent electric dipole moment of the nanorods with transient electric birefringence technique. Experimental results on nanorods with different sizes show that the dipole moment is linear to the particle volume, indicating that it originates from the non-centrosymmetric hexagonal lattice. The elongation of the nanocrystals also results in the anisotropic inter-particle interaction. One of the consequences is the formation of liquid crystalline phases when the nanorods are dispersed in solvent to a high enough

  4. Selenomethionine Se 75 thymus scans in myasthenia gravis

    Energy Technology Data Exchange (ETDEWEB)

    Toole, J.F.; Cowan, R.; Maynard, D.; Witcofski, R.L.; Janeway, R.

    1975-01-01

    In 1966, Toole and Witcofski introduced selenomethionine Se 75 mediastinal scanning as a diagnostic test for thymomas. Since then we have performed such scans on patients with myasthenic syndrome. Because the technique is atraumatic, safe, and accurate, it can be performed on critically ill myasthenics. Two hundred and fifty microcuries of selenomethionine Se 75 is injected intravenously. Within 1 hour the mediastinum from the suprasternal notch to the ziphoid process is scanned, using a 2 x 3 inch scanner. Delayed scans have been made in a few instances but they have not increased the number of positive cases. Selenomethionine Se 75 is incorporated into tissues undergoing rapid protein synthesis such as thyroid, pancreas, liver, and lymphomas. Of the 34 mediastinal scans performed on myasthenics between 1966 and December 31, 1974, 4 were positive for thymoma. In addition, there was a positive scan with uptake in an area of atelectasis of the lung adjacent to the mediastinum. Of interest is the fact that 1 patient with carcinoma of the lung had a positive scan over the lesion. In 13 patients with chronic lymphatic leukemia the mediastinal scans were negative. In another patient with a mediastinal mass noted on chest x-ray, a variety of differential diagnostic possibilities were considered, such as pericardial cyst, dermoid, and aneurysm. A selenomethionine scan was strongly positive, suggesting a thymoma which subsequent surgery confirmed.

  5. Explaining the Principle of Mala in Se

    DEFF Research Database (Denmark)

    Dige, Morten

    2012-01-01

    Certain methods and weapons are traditionally considered to be "mala in se", i.e. evil in themselves. Examples are mass rape campaigns and land mines. The article examines different interpretations of the principle that belligerents ought not to use such means. Some interpretations are reductionist...... in the sense that they see the principle as an instance of other principles regulating conduct in war (jus in bello), namely the principles of discrimination and proportionality. I suggest a horizontal and a vertical dimension of the latter. Resort to violence can then be unjustified if 1) the persons......-one should have to endure. I defend the vertical dimension of proportionality as a key to understanding the principle of mala in se and consider whether it leads to an absolute prohibition against such means...

  6. Magnetothermoelectric properties of Bi2Se3

    Science.gov (United States)

    Fauqué, Benoît; Butch, Nicholas P.; Syers, Paul; Paglione, Johnpierre; Wiedmann, Steffen; Collaudin, Aurélie; Grena, Benjamin; Zeitler, Uli; Behnia, Kamran

    2013-01-01

    We present a study of entropy transport in Bi2Se3 at low temperatures and high magnetic fields. In the zero-temperature limit, the magnitude of the Seebeck coefficient quantitatively tracks the Fermi temperature of the three-dimensional Fermi surface at the Γ point as the carrier concentration changes by two orders of magnitude (1017 to 1019 cm-3). In high magnetic fields, the Nernst response displays giant quantum oscillations indicating that this feature is not exclusive to compensated semimetals. A comprehensive analysis of the Landau level spectrum firmly establishes a large g factor in this material and a substantial decrease of the Fermi energy with increasing magnetic field across the quantum limit. Thus, the presence of bulk carriers significantly affects the spectrum of the intensively debated surface states in Bi2Se3 and related materials.

  7. Properties of the CuGaSe2 and CuInSe2 (001) surface

    International Nuclear Information System (INIS)

    Deniozou, T.

    2005-01-01

    The main task of this work was to investigate the (001) CuGaSe 2 and CuInSe 2 surface in dependence of preparation and stoichiometry. The knowledge of the atomic structure as well as other surface properties is important in respect to optimization of novel thin film solar cells. For the characterization of the layers mainly Auger electron Spectroscopy, low-energy electron diffraction and photoelectron spectroscopy were implemented. The development of an appropriate procedure with Ar + sputtering and annealing combined with decapping enabled the preparation of clean and well-ordered surfaces. Different surface structures were observed in dependence of the layer preparation and composition. A (4 x 1) reconstruction was observed for the first time on CuGaSe 2 layers grown with a moderate Cu-excess after preparation by sputtering and annealing. Similarly a (4 x 2) reconstruction was detected on CuInSe2 surfaces of Cu-poor layers. A reconstruction could be also observed on Cu-poorer layers, however the facets/steps could not be completely removed. Cu-richer layers were facet-free, however the observed reconstruction was also weaker. Thus it was shown that in contrary to recent expectations, according to which only the (112) surface is stable, also the (001) can be stable under particular conditions. The appearance of facets or steps is correlated with the presence of CuIn 3 Se 5 or CuGa 3 Se 5 phases. This information is furthermore important for the understanding of grain boundaries in polycrystalline CuGaSe 2 and CuInSe 2 . Binding energy shifts were observed for the first time on all Se3d, In4d, Ga3d, Cu3d core levels of the reconstructed surfaces. By comparison with results from the literature from the similar ZnSe (100) surface a modell for the (4 x 2) reconstruction was proposed. The surface components in the Se3d, In4d and Cu3d emission were attributed to Se dimers or In and Cu adatoms respectively. The x 1 periodicity of the (4 x 1) reconstruction of CuGaSe 2 is

  8. Synthèse et spectroscopie IR:

    African Journals Online (AJOL)

    BUREAU

    Synthèse de HCs5P2W18O62.16H2O et application à l'adsorption de la matière ... Résumé. La présente étude porte sur l'adsorption d'un colorant, le bleu de méthylène (BM), par un hétéropolyanion saturé ..... Adsorption of a gas mixture on ...

  9. Double beta decay of 82Se

    International Nuclear Information System (INIS)

    Elliott, S.R.; Hahn, A.A.; Moe, M.K.; Nelson, M.A.; Vient, M.A.

    1992-01-01

    The two-neutrino double beta decay of 82 Se has been measured during a 20 244 h run resulting in a half-life of 1.08 -0.06 +0.26 x10 20 years (68% C.L.). No candidate events for the zero-neutrino double beta decay during 21 924 h results in a half-life limit of 2.7x10 22 years at the 68% confidence level

  10. Thermoelectric properties of SnSe compound

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Lu, Pengfei, E-mail: photon@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wu, Liyuan; Han, Lihong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Liu, Gang [School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Song, Yuxin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2015-09-15

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data.

  11. Experience with the SE in Germany

    Directory of Open Access Journals (Sweden)

    Jochem Reichert

    2008-03-01

    Full Text Available A rather significant proportion of the Societas Europaeas (the European Company, or SE formed to date have had German roots. German corporate law has been enriched by an interesting alternative which meanwhile seems to have gained momentum. This contribution focuses on SEs incorporated by German entrepreneurs and provides an interesting account concerning the use of SEs in Germany in practice, such as Allianz, Fresenius, BASF and Porsche. Has the SE been used to circumvent rigid company law provisions or is it a more flexible and effective tool, perhaps, for company mobility? The practical motives behind setting up this company form are also reflected upon. These include: the facilitation of cross-border mergers; transfer of the registered office; the ‘European’ image; a more flexible form of co-determination in large companies (reduction of the number of supervisory board members; avoidance and freezing of co-determination for medium-sized enterprises; the appeal of the one-tier system and its endangerment by German co-determination; and flat and uniform structures for company groups. The author also briefly discusses some of the problems arising from the formation of SEs in Germany. He ultimately concludes that practice has shown that it is possible to work with the legal regime of the SE in Germany, which adds a new company form to those available in that Member State.

  12. Thermoelectric properties of SnSe compound

    International Nuclear Information System (INIS)

    Guan, Xinhong; Lu, Pengfei; Wu, Liyuan; Han, Lihong; Liu, Gang; Song, Yuxin; Wang, Shumin

    2015-01-01

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data

  13. Forming Glasses from Se and Te

    Directory of Open Access Journals (Sweden)

    Pierre Lucas

    2009-10-01

    Full Text Available Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared range and their stability against crystallization. These glasses can be shaped into sophisticated optical devices such as optical fibers, planar guides or lenses. Nevertheless, their transparencies are limited at about 12 μm (depending on the thickness of the optical systems due to the relatively small mass of the Se element. On the other hand, tellurium is heavier and its use in substitution for Se permits to shift the IR cutoff beyond 20 μm. However, the semimetallic nature of Te limits its glass formation ability and this glass family is known to be unstable and consequently has found application as phase change material in the Digital Versatile Disk (DVD technology. In this paper, after a review of selenide glasses and their applications, it will be shown how, in a recent past, it has been possible to stabilize tellurium glasses by introducing new elements like Ga or I in their compositions.

  14. Qué se sabe de bullying

    Directory of Open Access Journals (Sweden)

    B. Ricardo Musalem, Ps.

    2015-01-01

    Full Text Available Se define bullying como una dinámica de maltrato sistemática que ocurre entre iguales de manera persistente. Es considerado un problema de salud pública debido a su prevalencia y las consecuencias que tiene en todos sus participantes: en los agresores, en las víctimas, en los espectadores, en los padres y familias, en la comunidad escolar y en la sociedad en general. Las investigaciones muestran efectos a corto, mediano y largo plazo en el desarrollo emocional y social de niños y adolescentes. Se ha constatado una relación del acoso escolar con las patologías físicas, psicosomática y de salud mental en niños, adolescentes y en la vida adulta. En este artículo se describen las características individuales, las relacionales, los factores conocidos como de riesgo y factores protectores, la prevalencia y los programas de abordaje integral del fenómeno. Son múltiples los estudios que muestran la efectividad de la aplicación de estos programas de intervención, diseñados en función de los conocimientos acumulados.

  15. Patrimonio cultural: lo intangible se hace tangible

    Directory of Open Access Journals (Sweden)

    William Heredia Orjuela

    2004-11-01

    Full Text Available Se presentan tres reflexiones a manera de ensayo, elaboradas por estudiantes de vii semestre de la Facultad de Administración de Empresas Turísticas y Hoteleras. El tema central que engloba los escritos es el de la responsabilidad frente al patrimonio cultural, su valoración y su relación con el turismo. En el ensayo La protección del patrimonio cultural como reflejo del ser humano, la estudiante cecilia hinosTrosa hace un llamado de atención frente al problema del tráfico ilícito de bienes que conlleva la pérdida de testimonios de la cultura humana. El escrito de la estudiante mariel cecilia hernández destaca las bondades de recuperar las tradiciones y de cómo éstas se pueden difundir a través del turismo. Por último, el estudiante William heredia hace una reflexión sobre la tangibilidad de lo intangible, en el ensayo Patrimonio Cultural: lo tangible se hace intangible, donde destaca la declaratoria del Carnaval de Barranquilla como patrimonio oral e intangible de la humanidad.

  16. Thermally stimulated properties in ZnSe:Tb and ZnSe:(Mn, Tb) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2018-02-01

    Thermoluminescence studies were performed of ZnSe:Tb and ZnSe:(Mn, Tb) phosphors. A method of preparation for ZnSe phosphors doped with Tb and (Mn, Tb) has been discussed. The thermoluminescence (TL) properties of these phosphors have been studied from 100 to 370 K temperature after exciting by UV radiation (365 nm) at three uniform heating rates 0.4, 0.6 and 0.9 K/s. The trapping parameters like trap depth, lifetime of electrons and capture cross-section have also been determined using various methods.

  17. Absorption Spectra of CuGaSe2 and CuInSe2 Semiconducting Nanoclusters

    KAUST Repository

    Mokkath, Junais Habeeb

    2015-10-01

    The structural and optical properties of the chalcopyrite CunGanSe2n and CunInnSe2n nanoclusters (n = 2, 4, 6, and 8) are investigated as a function of the size using a combination of basin-hopping global optimization and time-dependent density functional theory. Although the lowest energy structures are found to show almost random geometries, the band gaps and absorption spectra still are subject to systematic blue shifts for decreasing cluster size in the case of CunGanSe2n, indicating strong electron confinement. The applicability of the nanoclusters in photovoltaics is discussed. © 2015 American Chemical Society.

  18. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lam, N S [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Wong, K W [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Li, Q [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Zheng, Z [Department of Physics, Chinese University of Hong Kong, Hong Kong (China); Lau, W M [Surface Science Western, University of Western Ontario, London, ON, N6A 5B7 (Canada)

    2007-10-17

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to {approx}60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version.

  19. Controllable size reduction of CdSe nanowires through the intermediate formation of Se-coated CdSe nanowires using acid and thermal treatment

    International Nuclear Information System (INIS)

    Lam, N S; Wong, K W; Li, Q; Zheng, Z; Lau, W M

    2007-01-01

    Thinning of CdSe nanowires (NWs) with controllable size was achieved by a simple acid treatment and subsequent annealing on thick CdSe NWs synthesized from vapour phase growth. During acid treatment, not only the undesired impurities such as native oxides of Cd and Se could be etched, but surface reactions of CdSe NWs were also observed, resulting in the formation of a layer of elemental Se around a thinner CdSe core. As a result, a heterostructure of Se - CdSe nanostructure formed after acid treatment of CdSe NWs. Upon thermal annealing, the Se shell was effectively removed and thinned stoichiometric single-crystalline CdSe NWs could be obtained. It was observed that NWs could be thinned by up to ∼60% in diameter by acid treatment and subsequent Se thermal desorption. The degree of thinning was controllable by adjusting the duration of acid treatment. The success of the thinning of CdSe NWs by simple acid treatment and the annealing process reported here opens a new processing route for obtaining stoichiometric CdSe NWs with controllable size reduction and improved aspect ratio. This can undoubtedly broadly improve the range of applications of 1D CdSe nanostructures and allow more exploration of their uni-directional properties. A correction was made to the last paragraph of section 3 on 18 September 2007. The corrected electronic version is identical to the print version

  20. Highly luminescent CdSe/ZnSe core-shell quantum dots of one-pot preparation in octadecene

    NARCIS (Netherlands)

    Zeng, Q.; Kong, X.; Zhang, Y.; Zhang, H.

    2008-01-01

    CdSe/ZnSe core-shell quantum dots were synthesized using a new one-pot procedure where the core was prepared in octadecene. A ZnSe shell around a CdSe nanoparticle was formed by the reaction of selenium-richness on the surfaces of CdSe nanoparticles with Zn2+ from the injected zinc stearate

  1. Stable and metastable phases in reciprocal systems PbSe + Ag2I2 Ag2Se + PbI2 and PbSe + CdI2 = CdSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Safronov, E.V.

    2005-01-01

    Mutual system PbSe + Ag 2 I 2 = Ag 2 Se + PbI 2 is investigated. It is shown that diagonal Ag 2 Se-PbI 2 is stable. Liquidus surface and isothermal section at 633 K of phase diagram of PbSe-Ag 2 Se-PbI 2 system are built. Transformations directing to crystallization metastable ternary compound forming in PbSe-PbI 2 system and metastable polytype modifications of lead iodide in PbSe-Ag 2 Se-PbI 2 system at 620-685 K are studied. By hardening from molten state (1150-1220 K) new interstitial metastable phases crystallizing in CdCl 2 structural type are obtained in PbSe-Ag 2 Se-PbI 2 and PbSe + CdI 2 = CdSe + PbI 2 systems [ru

  2. Anchorage Areas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An anchorage area is a place where boats and ships can safely drop anchor. These areas are created in navigable waterways when ships and vessels require them for...

  3. Thermal analysis of chalcogenide glasses of the system (As/sub/2Se/sub/3)/sub/(1-x):(Tl/sub/2Se)/sub/x

    International Nuclear Information System (INIS)

    Majid, C.A.

    1987-01-01

    In this paper differential thermal analysis (DTA) measurements of chalcogenide glasses of the system (As/sub/2Se/sub/3)/sub/(1-x): (Tl/sub/2Se)/sub/x, with x=0, 0.125, 0.25 and 0.50 are reported. The glass-forming tendencies of these materials have been calculated. The glass-forming tendency of As/sub/2Se/sub/3 has been found to be the highest among the member glasses of this family of chalcogenides. It was found that the glass-forming tendency of As/sub/2Se/sub/3 decreasing gradually at the Tl/sub/2/Se concentration increases. Tl/sub/2Se additions lower the glass transition temperature T/sub/q and the area under the endothermic peak for glass transition temperature, suggesting a tendency for relatively weaker bonding and hence less stability of Tl-rich glass compositions. These studies show that Tl/sub/2Se concentrations result in glasses with progressively higher crystallization tendencies. (author)

  4. Symmetry effects in neutron scattering from isotopically enriched Se isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Lachkar, J.; Haouat, G.; McEllistrem, M. T.; Patin, Y.; Sigaud, J.; Cocu, F.

    1975-06-01

    Differential cross sections for neutron elastic and inelastic scattering from {sup 76}Se, {sup 78}Se, {sup 80}Se and {sup 82}Se, have been measured at 8-MeV incident neutron energy and from {sup 76}Se and {sup 82}Se at 6- and 10-MeV incident energies. The differences observed in the elastic scattering cross sections are interpretable as the effects of isospin term in the scattering potentials. A full analysis of the elastic scattering data are presented.

  5. EXAFS cumulants of CdSe

    International Nuclear Information System (INIS)

    Diop, D.

    1997-04-01

    EXAFS functions had been extracted from measurements on the K edge of Se at different temperatures between 20 and 300 K. The analysis of the EXAFS of the filtered first two shells has been done in the wavevector range laying between 2 and 15.5 A -1 in terms of the cumulants of the effective distribution of distances. The cumulants C 3 and C 4 obtained from the phase difference and the amplitude ratio methods have shown the anharmonicity in the vibrations of atoms around their equilibrium position. (author). 13 refs, 3 figs

  6. Thermoelectric power in n-InSe

    International Nuclear Information System (INIS)

    Casanovas, A.; Cantarero, A.; Segura, A.

    1985-01-01

    Thermoelectric power of InSe samples doped with tin has been measured as functions of the doping concentration in the range of 0.01 to 10% Sn and of the temperature in the range of 50 to 550 K. In the low temperature range the results obtained are coherent with the two-dimensional behaviour of electrons proposed by other authors. About 100 K the results can be explained successfully by introducing the same scattering mechanisms used to interpret the temperature dependence of the electron mobility

  7. Colloidal CdSe Quantum Rings.

    Science.gov (United States)

    Fedin, Igor; Talapin, Dmitri V

    2016-08-10

    Semiconductor quantum rings are of great fundamental interest because their non-trivial topology creates novel physical properties. At the same time, toroidal topology is difficult to achieve for colloidal nanocrystals and epitaxially grown semiconductor nanostructures. In this work, we introduce the synthesis of luminescent colloidal CdSe nanorings and nanostructures with double and triple toroidal topology. The nanorings form during controlled etching and rearrangement of two-dimensional nanoplatelets. We discuss a possible mechanism of the transformation of nanoplatelets into nanorings and potential utility of colloidal nanorings for magneto-optical (e.g., Aharonov-Bohm effect) and other applications.

  8. Mesoscopic NbSe3 wires

    International Nuclear Information System (INIS)

    Zant, H.S.J. van der; Kalwij, A.; Mantel, O.C.; Markovic, N.

    1999-01-01

    We have fabricated wire structures with (sub)micron sizes in the charge-density wave conductor NbSe 3 . Electrical transport measurements include complete mode-locking on Shapiro steps and show that the patterning has not affected the CDW material. Our mesoscopic wires show strong fluctuation and hysteresis effects in the low-temperature current-voltage characteristics, as well as a strong reduction of the phase-slip voltage. This reduction can not be explained with existing models. We suggest that single phase-slip events are responsible for a substantial reduction of the CDW strain in micron-sized systems. (orig.)

  9. Microstructure and thermoelectric properties of CuInSe2/In2Se3 compound

    Science.gov (United States)

    Wang, Kang; Feng, Jing; Ge, Zhen-Hua; Qin, Peng; Yu, Jie

    2018-01-01

    CuInSe2 powders were synthesized by solvothermal method, and then the CuInSe2/In2Se3 bulk samples were fabricated by spark plasma sintering (SPS) technique. To investigate the phase composition, the powders were determined by X-ray diffraction (XRD). The microstructures of the powders and bulk samples were observed by scanning electron microscopy (SEM). The transportation of the electronic properties and thermal conductivity were measured at room temperature to 700 K. According to the results, the CuInSe2 powders appeared in flower-like patterns which ranged from 3 μm to 6 μm. CuInSe2 powders were synthesized at 180∘C with a chalcopyrite structure. The Seebeck coefficient increased significantly in composite thermoelectric materials up to 200μVṡK-1 at 623 K. The thermal conductivity of the sample significantly decreases from the room temperature to 700 K. The CuInSe2 bulk composite by solvothermal method achieves the highest ZT value of 0.187 at 700 K.

  10. Biogeochemical and hydrological controls in mobilizing Se in a saline wetland environment

    Science.gov (United States)

    Datta, S.; Hettiarachchi, G. M.; Crawford, M.; Karna, R.; Allmendinger, N. E.; Khatiwada, R.

    2010-12-01

    Selenium (Se) contamination in watersheds remains a challenge to water and land and wildlife managers throughout the west and mid west of US. In that sense, understanding the fundamentals of Se mobilization, fixation and bioconcentration is the current research endeavor. The challenge for Se research is developing watershed-geochemical models that are well founded in Se geochemical/biologcial principles that can be applied in a wide range of situations to inform decisions. Pariette Wetlands, a 9000 acre Bureau of Land Management controlled wetland system composed of 20 ponds located at the confluence of Pariette Draw and the Green River is the present location of this study. The agricultural and irrigation practices and the water-rock interactions leading to salinization can be associated with changes in Se chemistry in the rivers. Since its inception Pariette Wetlands has been home to a rich and diverse wetland ecosystem located in the arid Uintah Basin of Northeastern Utah. Detailed sampling of surficial sediments (0-1 m) from stream banks, channel beds and for water sampling have been undergone in 2 separate field trips throughout the entire reach of the wetland. To establish Pariette Draw’s contribution of Se to the Green river, water and sediments were also sampled from the Green River up and downstream of its confluence with Pariette Draw. In situ measurements of water parameters within the wetland suggest a clear trend of increased pH from upstream, 8, to downstream, 9.2 and combined with TDS suggest a pH controlled saline environment system. The headwaters near Flood Control Dam have an added input of Se from a possible irrigation source upstream in Pleasant Valley area while Se drastically decreases downstream towards the Red Head Pond. Se fractionation in sediments is being analyzed via a sequential extraction procedure to locate the labile fractions of mostly inorganic bound Se. Solid state speciation of Se via μ-XRF aided μ-XANES is being combined

  11. Phase transitions in thin films of Sn-Sb-Se system

    International Nuclear Information System (INIS)

    Samsudi Sakrani; Abdalla Belal Adam; Yussof Wahab

    1998-01-01

    The preparation and formation of covalent ternary Sn-Sb-Se system were investigated. A solid state reaction technique was employed whereby the evaporated multilayers of Sn/Se/Sb/Sn reacted chemically at a fixed temperature of 240 o C and were allowed to a room temperature slow-cooling. X-ray diffraction analysis showed that phase changes occurred in the system, with indication of amorphization for the predicted Sn 9 .3Sb 8 .1Se 4 4.9 and Sn 1 3.2Sb 4 3.4Se 4 3.4 compositions. These enabled the preliminary topological phase transitions of Sn-Sb-Se system according to the Gibb's triangle in which the areas of crystalline-amorphous were located. (Author)

  12. Lo que se debe a las cimentaciones

    Directory of Open Access Journals (Sweden)

    Oroviogoicoechea, Alberto

    1975-05-01

    Full Text Available This article describes: the problems that arise when the foundations has to act on soils with low consistency or when very narrow tolerances have to be met; the origin of the above mentioned problems; the requirements that are not really necessary, with suitable examples; the absolute and relative admissible magnitudes of differential settlements in concrete structures, walls, partitions and metal structures; the tolerances for mechanical installations; recommendations for projects and a table that sums up the proposed tolerances for relative foundations.En el artículo se describen: los problemas que surgen cuando la cimentación ha de actuar sobre terrenos poco consistentes o cuando se quieren cumplir tolerancias muy estrechas; de dónde provienen dichos problemas; las exigencias que no son realmente necesarias, con ejemplos apropiados; las magnitudes absolutas y relativas admisibles de asientos diferenciales, en estructuras de hormigón, muros, tabiques y estructuras metálicas; las tolerancias para instalaciones mecánicas; recomendaciones para proyecto, y una tabla que recoge las tolerancias propuestas para asientos relativos.

  13. Stretched Exponential relaxation in pure Se glass

    Science.gov (United States)

    Dash, S.; Ravindren, S.; Boolchand, P.

    A universal feature of glasses is the stretched exponential relaxation, f (t) = exp[ - t / τ ] β . The model of diffusion of excitations to randomly distributed traps in a glass by Phillips1 yields the stretched exponent β = d[d +2] where d, the effective dimensionality. We have measured the enthalpy of relaxation ΔHnr (tw) at Tg of Se glass in modulated DSC experiments as glasses age at 300K and find β = 0.43(2) for tw in the 0 Se100-x glasses as x increases to 20%, the length of the polymeric Sen chains between the Ge-crosslinks decreases to n = 2. and the striking relaxation effects nearly vanish. J.C. Phillips, Rep.Prog.Phys. 59 , 1133 (1996). Supported by NSF Grant DMR 08-53957.

  14. Escuela para señoritas, Inglaterra

    Directory of Open Access Journals (Sweden)

    Stillman y Eastwlck-Field, Arquitectos

    1963-02-01

    Full Text Available The object was to design part of a new building which had been seriously damaged during the war, so that the old and new parts would blend into a pleasant whole, with a capacity for 600 girls. The new designs avoid the glass box style of school buildings, and glass walls have been adopted only on the ground floor, thus giving an impression of light and airiness to what used to be a partial basement. Classrooms have been designed in a simple manner, and give the impression of conventional rooms. Simple lines and materials have been chosen throughout. Strong contrasts in the external finish have been avoided, and colours provide a relaxing background to the intensive activities of the students. A constructional feature is the use of prefabricated concrete joists and supports. Outer walls consist of brick panels filling in the space between the visible concrete framework. Ceilings are of insulating boards, and the floors are covered with linoleum. Special attention has been devoted to the hall. In this case the roof is of white gypsum, and the only features are the grills covering the fluorescent lighting. The walls of this hall are of glass, and are covered with heavy velvet curtains. A balcony with hardwood posts adds a simple and friendly feature to the building. The furniture and drapery have been carefully chosen. Camden school has a rigid tradition of individualism and fine education, and the new building has succeeded in maintaining the exclusive quality of the older parts, as well as offering an overall impression of up to date construction.El problema consistía en proyectar un nuevo núcleo para un edificio que había sido seriamente bombardeado durante la guerra, de tal modo que las partes antiguas y nuevas formasen un conjunto agradable y con capacidad para más de 600 chicas. En la nueva construcción se ha evitado el carácter de «cajas de cristal» de las nuevas escuelas ordinarias y se han empleado muros de cristal solamente en la

  15. CuInSe2 nano-crystallite reaction kinetics using solid state reaction from Cu2Se and In2Se3 powders

    International Nuclear Information System (INIS)

    Hsiang, Hsing-I; Lu, Li-Hsin; Chang, Yu-Lun; Ray, Dahtong; Yen, Fu-Su

    2011-01-01

    Highlights: → CuInSe 2 phase increased gradually accompanied with a decrease in γ-In 2 Se 3 and no intermediate phase during calcination. → CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a one-dimensional diffusion-controlled reaction with apparent activation energy of about 122.5 kJ/mol. → The solid reaction kinetics may be dominated by the diffusion of In 3+ ions. - Abstract: The reaction mechanism and CuInSe 2 formation kinetics using a solid state reaction from Cu 2 Se and In 2 Se 3 powders synthesized using a heating up process were investigated using X-ray diffractomy (XRD) and transmission electron microscopy (TEM). It was observed that the CuInSe 2 phase increased gradually, accompanied with a decrease in γ-In 2 Se 3 with no intermediate phase as the calcination temperature and soaking time were increased. The reaction kinetics was analyzed using the Avrami and polynomial kinetic model, suggesting that CuInSe 2 formation from Cu 2 Se and In 2 Se 3 powders follows a diffusion-controlled reaction with an apparent activation energy of about 122.5-182.3 kJ/mol. Cu 2 Se and In 2 Se 3 phases react and directly transform into CIS without the occurrence of any intermediate phase and the size of the newly formed CuInSe 2 crystallites was close to that of the Cu 2 Se reactant particle based on the TEM results, which indicated that the solid reaction kinetics may be dominated by the diffusion of In 3+ ions.

  16. Green synthesis of ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) using a new, rapid and room temperature photochemical approach

    Energy Technology Data Exchange (ETDEWEB)

    Molaei, M., E-mail: m.molaei@vru.ac.ir; Bahador, A.R.; Karimipour, M.

    2015-10-15

    In this work, ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) were synthesized using a one-pot, rapid and room temperature photochemical method. UV illumination provided the required energy for the chemical reactions. Synthesized NCs were characterized using X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), UV–vis and photoluminescence (PL) spectroscopy. XRD pattern indicated cubic zinc blende structure for ZnSe NCs and the TEM image indicated round-shaped particles, most of which had a diameter of about 3 nm. Band gap of ZnSe NCs was obtained as about 3.6 eV, which was decreased by increasing the illumination time. Synthesized NCs indicated intensive and narrow emission in the UV-blue area (370 nm) related to the excitonic recombination and a broad band emission with a peak located at about 490 nm originated from the DAP (donor–acceptor pairs) recombination. ZnS shell was grown on ZnSe cores using a reaction based on the photo-sensitivity of Na{sub 2}S{sub 2}O{sub 3}. For ZnSe@ZnS core–shell NCs, XRD diffraction peaks shifted to higher angles. TEM image indicated a shell around cores and most of the ZnSe@ZnS NCs have a diameter of about 5 nm. After the ZnS growth, ZnSe excitonic emission shifted to the longer wavelength and PL intensity was increased considerably. PL QY was obtained about 11% and 17% for ZnSe and ZnSe@ZnS core–shell QDs respectively. - Highlights: • A green photochemical approach was reported for synthesis of ZnSe NCs. • ZnS shell was grown around ZnSe using a new method. • Synthesis method was rapid, simple and at room temperature. • ZnSe NCs indicated a narrow UV-blue and a broad DAP emissions. • PL intensity was increased considerably by ZnS shell growth.

  17. Green synthesis of ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) using a new, rapid and room temperature photochemical approach

    International Nuclear Information System (INIS)

    Molaei, M.; Bahador, A.R.; Karimipour, M.

    2015-01-01

    In this work, ZnSe and core–shell ZnSe@ZnS nanocrystals (NCs) were synthesized using a one-pot, rapid and room temperature photochemical method. UV illumination provided the required energy for the chemical reactions. Synthesized NCs were characterized using X-ray diffraction spectroscopy (XRD), transmission electron microscopy (TEM), UV–vis and photoluminescence (PL) spectroscopy. XRD pattern indicated cubic zinc blende structure for ZnSe NCs and the TEM image indicated round-shaped particles, most of which had a diameter of about 3 nm. Band gap of ZnSe NCs was obtained as about 3.6 eV, which was decreased by increasing the illumination time. Synthesized NCs indicated intensive and narrow emission in the UV-blue area (370 nm) related to the excitonic recombination and a broad band emission with a peak located at about 490 nm originated from the DAP (donor–acceptor pairs) recombination. ZnS shell was grown on ZnSe cores using a reaction based on the photo-sensitivity of Na 2 S 2 O 3 . For ZnSe@ZnS core–shell NCs, XRD diffraction peaks shifted to higher angles. TEM image indicated a shell around cores and most of the ZnSe@ZnS NCs have a diameter of about 5 nm. After the ZnS growth, ZnSe excitonic emission shifted to the longer wavelength and PL intensity was increased considerably. PL QY was obtained about 11% and 17% for ZnSe and ZnSe@ZnS core–shell QDs respectively. - Highlights: • A green photochemical approach was reported for synthesis of ZnSe NCs. • ZnS shell was grown around ZnSe using a new method. • Synthesis method was rapid, simple and at room temperature. • ZnSe NCs indicated a narrow UV-blue and a broad DAP emissions. • PL intensity was increased considerably by ZnS shell growth

  18. Study of the 76788082Se(d,p)77798183Se reactions using polarized deuterons

    International Nuclear Information System (INIS)

    Montestruque, L.A.

    1978-01-01

    Differential cross sections and vector analyzing powers were measured at an incident deuteron energy of 12.5 MeV for the 76 78 80 82 Se(d,p) 77 79 81 83 Se reactions. The data are compared with the predictions of the DWBA theory to determine the l-value, spin, parity and spectroscopic factor of the resolved states. High resolution measurements were made with a 100 cm broad-range magnetic spectrograph to determine the excitation energies of the states studied, and the possible existence of contaminants in the targets. Definitive spin and parity assignments are made to 16 states in 77 Se, 22 states in 79 Se, 17 states in 81 Se, and 18 states in 83 Se, fifteen of which were previously assigned. In addition, tentative spin assignments were made to one state in 83 Se. The spectrograph measurements allowed the determination of the excitation energies of anumber of additional states in each isotope. Among the 76 states studied in this work, ther are 8 2P/sub 3/2/ states, 4 1F/sub 5/2/ states 6 2P/sub 1/2/ states 4 1G/sub 9/2/ states, 31 2D/sub 5/2/ states, 10 3S/sub 1/2/ states, and 13 2D/sub 3/2 states. A sum-rule analysis was made and the results compared to previous work and to the predictions of the simple pairing theory

  19. Synthesis and Characteristics of HgCdSe for IR Detection

    Science.gov (United States)

    2014-03-11

    HgCdSe layers. Positron annihilation spectroscopy measurements were carried out. These suggest the presence of p-type mercury vacancies in Hg1-xCdxSe...Photoelectron Spectroscopy Study of Oxide Removal Using Atomic Hydrogen for Large-Area II–VI Material Growth, Journal of Electronic Materials... Applications ,” K. Doyle, G. Brill, Y. Chen, T. H. Myers, S. Trivedi. 2012 SPIE Conference, San Diego CA (August 2012) “Determination of critical

  20. Opportunities and challenges for a sustainable energy policy in SE Europe: SE European Energy Community Treaty

    International Nuclear Information System (INIS)

    Mihajlov, Andjelka

    2010-01-01

    Energy demand continues to increase in turn raising concerns about energy supply. In this paper, the author has tried to systematize the role of the energy sector in South Eastern (SE) Europe in the context of the European energy policy process. This should make the energy sector in SE Europe more visible and open to substantial activities and appropriate funding. This is important to assure its full alignment with the European energy policy process, and in so doing, make it less fragile. According to the SE European Energy Community Treaty, parties to the Treaty are obliged to implement reforms in the energy and environmental sector in accordance with the European Union's respective policy. This paper raises awareness of the environmental requirements that have been set, of renewable energy and its implementation, at the same time pointing out that the response in SE Europe has been at a low level. It is believed that this paper could draw attention to the existing problems and could contribute to the establishment of a common integrated energy market in SE Europe and the EU. (author)

  1. ZnSe MSM photodetectors prepared on GaAs and ZnSe substrates

    International Nuclear Information System (INIS)

    Lin, T.K.; Chang, S.J.; Su, Y.K.; Chiou, Y.Z.; Wang, C.K.; Chang, S.P.; Chang, C.M.; Tang, J.J.; Huang, B.R.

    2005-01-01

    Homoepitaxial and heteroepitaxial ZnSe metal-semiconductor-metal (MSM) photodetectors were both fabricated and characterized. It was found that homoepitaxial ZnSe MSM photodetector could provide us smaller dark current and large photocurrent. With an incident wavelength of 448 nm, it was found that the maximum responsivities for the homoepitaxial and heteroepitaxial ZnSe photodetectors were 0.128 and 0.045 A/W, which corresponds to a quantum efficiency of 36 and 12%, respectively. Furthermore, it was found that we achieved the minimum noise equivalent power (NEP) of 7.6 x 10 -13 W and the maximum normalized detectivity (D *) of 9.3 x 10 11 cm Hz 0.5 W -1 from our homoepitaxial ZnSe photodetector. In contrast, NEP and D * of the heteroepitaxial ZnSe photodetector were 2.9 x 10 -12 W and 2.44 x 10 11 cm Hz 0.5 W -1 , respectively

  2. Thermoelectric study of Ag doped SnSe-Sb2Se3 based alloy

    Science.gov (United States)

    Das, Anish; Talukdar, M.; Kumar, Aparabal; Sarkar, Kalyan Jyoti; Dhama, P.; Banerji, P.

    2018-05-01

    In this article we have synthesized p-type alloy of SnSe and Sb2Se3 (10 atomic %) to study the thermoelectric transport properties. The alloy was prepared by melt grown technique followed by spark plasma sintering and latter doped with 2 atomic % Ag to compensate the carrier density in order to achieve higher electrical conductivity (σ). Out of these, the doped sample resulted in the maximum figure of merit, ZT˜0.7 at 773 K due to the existence of the secondary phase AgSbSe2 and reduced lattice thermal conductivity (0.61 W m-1 K-1 at 300 K). The fitted lattice thermal conductivity shows that point defect and Umklapp scattering are the primary process of phonon scattering for all the samples whereas the fitted mobility data confirms acoustic phonon scattering along with point defect and grain boundary scattering to be the main carrier scattering mechanism. More over room temperature carrier density and electrical conductivity are found to increase for the doped sample which further corroborate (90%)SnSe-(10%)Sb2Se3:2%Ag to be a potential candidate for highly efficient thermoelectric materials.

  3. No se olviden de Bernardo (Kordon

    Directory of Open Access Journals (Sweden)

    Eduardo Romano

    2006-09-01

    Full Text Available No casualmente el título coincide con un eslogan muy divulgado y que intenta conservar la memoria acerca de un hecho y de una víctima. No lo son también aquellos escritores a los que una mezquina política de mercado condena poco menos que al olvido, luego de que durante décadas animaran el proceso literario nacional y obtuvieran reconocimientos de diverso carácter por su producción? No me cabe duda de que Bernardo Kordon (1915-2002 fue uno de esos animadores de la narrativa nacional, al que es indispensable volver para que se entiendan mejor algunos cambios sucedidos en ella a partir de los años 50, aunque su culminación date de la década del 60 y un poco más.

  4. La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer

    OpenAIRE

    Pablo Lorente Muñoz

    2011-01-01

    Emilio Sánchez Miguel (Coord.). La lectura en el aula. Qué se hace, qué se debe hacer y qué se puede hacer. Graó, col. Crítica y Fundamentos, 27. Barcelona, 2010. 382 págs. ISBN: 978-84-7827-892-3

  5. Structure of Se-rich As-Se glasses by high-resolution x-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Golovchak, R.; Kovalskiy, A.; Miller, A. C.; Jain, H.; Shpotyuk, O.

    2007-01-01

    To establish the validity of various proposed structural models, we have investigated the structure of the binary As x Se 100-x chalcogenide glass family (x≤40) by high-resolution x-ray photoelectron spectroscopy. From the composition dependence of the valence band, the contributions to the density of states from the 4p lone pair electrons of Se and the 4p bonding states and 4s electrons of Se and As are identified in the top part of the band. The analysis of Se 3d and As 3d core-level spectra supports the so-called chain crossing model for the atomic structure of Se-rich As x Se 100-x bulk glasses. The results also indicate small deviations (∼3-8%) from this model, especially for glass compositions with short Se chains (25 40 Se 60 and of Se-Se-Se fragments in a glass with composition x=30 is established

  6. Se-Se isoelectronic centers in high purity CdTe

    Energy Technology Data Exchange (ETDEWEB)

    Najjar, Rita; Andre, Regis; Mariette, Henri [CEA-CNRS, Nanophysique et Semiconducteurs, Institut Neel, 25 rue des martyrs, 38042 Grenoble (France); Golnik, Andrzej; Kossacki, Piotr; Gaj, Jan A. [Institute of Experimental Physics, University of Warsaw, Hoza 69, 00-681 Warsaw (Poland)

    2010-06-15

    We evidence zero-dimensional exciton states trapped on isoelectronic Se centers in CdTe quantum wells, {delta}-doped with Se. Thanks to special precautions taken to have very high purity CdTe heterostructures, it is possible to observe, in photoluminescence spectra, sharp discrete lines arising from individual centers related to the Se doping. These emission lines appear at about 40 meV below the CdTe band gap energy. The most prominent lines are attributed to the recombination of excitons bound to nearest-neighbor selenium pairs in a tetrahedral CdTe environment. This assignment is confirmed by a common linear polarization direction of the emitted light, parallel to <110>. These excitons localized on individual isoelectronic traps are good candidates as single photon emitters (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Synthesis and optical study of green light emitting polymer coated CdSe/ZnSe core/shell nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S.K., E-mail: surya@pu.ac.in [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India); Sharma, Mamta [Department of Physics, Center of Advanced Study in Physics, Panjab University, Chandigarh 160 014 (India)

    2013-05-15

    Highlights: ► Synthesis of Polymer coated core CdSe and CdSe/ZnSe core/shell NCs. ► From TEM image, the spherical nature of CdSe and CdSe/ZnSe is obtained. ► Exhibiting green band photoemission peak at 541 nm and 549 nm for CdSe core and CdSe/ZnSe core/shell NCs. ► The shell thickness has been calculated by using superposition of quantum confinement energy model. - Abstract: CdSe/ZnSe Core/Shell NCs dispersed in PVA are synthesized by chemical method at room temperature. This is characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV/Vis spectra and photoluminescence spectroscopy (PL). TEM image shows the spherical nature of CdSe/ZnSe core/shell NCs. The red shift of absorption and emission peak of CdSe/ZnSe core/shell NCs as compared to CdSe core confirmed the formation of core/shell. The superposition of quantum confinement energy model is used for calculation of thickness of ZnSe shell.

  8. Optical properties of thermally annealed CdZnSe/ZnSe quantum dots

    International Nuclear Information System (INIS)

    Margapoti, Emanuela

    2010-01-01

    To analyse the diffusion characteristics, photoluminescence (PL) spectroscopy has been carried out in extensive detail on single, as well as, ensembles of thermally annealed (TA) CdSe/ZnSe QDs. For a series of QD-ensembles, each annealed for t A = 30 s at temperatures from T A = 300-550 C, the change in the QD-composition has been calculated from the blue-shift of the exciton ground-state PL-emission, using a concentration function based on Fick's laws of diffusion. The diffusion length (L D ) and the activation energy (E A ) have been determined thereof. For the studied QDs, E A has been evaluated to be 2.2 eV. Additionally, TA results also in an enhancement of the PL-intensity and reduction of the full-width-at-half maximum (FWHM) of the spectra. This point towards an increased homogeneity of the QD-size and composition, and decrease in the concentration of defects around the QDs. For single CdSe/ZnSe QDs, TA has been varied from 100-240 C, in steps for 20 C, with t A kept fixed at 30 s. Finally, the evolution of the magneto-optic response with post-growth thermal annealing has been studied for both individual QDs and QD-ensembles. An external magnetic field, applied perpendicular to the plane of the QDs (Faraday configuration), results in Zeeman spin splitting of the ground exciton state. The emissions from the Zeeman-split states are left and right circularly polarized and from the degree of circular polarization (DCP), as well as, the spectral separation of the PL-peaks, the g-factor can be estimated. For CdSe/ZnSe QD-ensembles, the g-factor has been observed to change sign with TA. (orig.).

  9. Optical properties of thermally annealed CdZnSe/ZnSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Margapoti, Emanuela

    2010-07-01

    To analyse the diffusion characteristics, photoluminescence (PL) spectroscopy has been carried out in extensive detail on single, as well as, ensembles of thermally annealed (TA) CdSe/ZnSe QDs. For a series of QD-ensembles, each annealed for t{sub A} = 30 s at temperatures from T{sub A} = 300-550 C, the change in the QD-composition has been calculated from the blue-shift of the exciton ground-state PL-emission, using a concentration function based on Fick's laws of diffusion. The diffusion length (L{sub D}) and the activation energy (E{sub A}) have been determined thereof. For the studied QDs, E{sub A} has been evaluated to be 2.2 eV. Additionally, TA results also in an enhancement of the PL-intensity and reduction of the full-width-at-half maximum (FWHM) of the spectra. This point towards an increased homogeneity of the QD-size and composition, and decrease in the concentration of defects around the QDs. For single CdSe/ZnSe QDs, TA has been varied from 100-240 C, in steps for 20 C, with t{sub A} kept fixed at 30 s. Finally, the evolution of the magneto-optic response with post-growth thermal annealing has been studied for both individual QDs and QD-ensembles. An external magnetic field, applied perpendicular to the plane of the QDs (Faraday configuration), results in Zeeman spin splitting of the ground exciton state. The emissions from the Zeeman-split states are left and right circularly polarized and from the degree of circular polarization (DCP), as well as, the spectral separation of the PL-peaks, the g-factor can be estimated. For CdSe/ZnSe QD-ensembles, the g-factor has been observed to change sign with TA. (orig.).

  10. Simultaneous speciation of arsenic (As(III), MMA, DMA, and As(V)) and selenium (Se(IV), Se(VI), and SeCN{sup -}) in petroleum refinery aqueous streams

    Energy Technology Data Exchange (ETDEWEB)

    Tonietto, Gisele B.; Godoy, Jose M.; Oliveira, Ana Cristina [Pontificia Universidade Catolica do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Souza, Marcia V. de [Petrobras/Cenpes, Research and Development Center, Rio de Janeiro (Brazil)

    2010-07-15

    High-performance liquid chromatography (HPLC) coupled to an ICP-MS with an octapole reaction system (ORS) has been used to carry out quantitative speciation of selenium (Se) and arsenic (As) in the stream waters of a refining process. The argon dimers interfering with the {sup 78}Se and {sup 80}Se isotopes were suppressed by pressurizing the octapole chamber with 3.1 mL min{sup -1} H{sub 2} and 0.5 mL min{sup -1} He. Four arsenic species arsenite - As(III), arsenate (As(V)), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) - and three inorganic Se species - selenite Se(IV), selenate Se(VI), and selenocyanate (SeCN{sup -}) - were separated in a single run by ion chromatography (IC) using gradient elution with 100 mmol L{sup -1} NH{sub 4}NO{sub 3}, pH 8.5, adjusted by addition of NH{sub 3}, as eluent. Repeatabilities of peak position and of peak area evaluation were better than 1% and about 3%, respectively. Detection limits (as 3{sigma} of the baseline noise) were 81, 56, and 75 ng L{sup -1} for Se(IV), Se(VI), and SeCN{sup -}, respectively, and 22, 19, 25, and 16 ng L{sup -1} for As(III), As(V), MMA, and DMA, respectively. Calibration curve R {sup 2} values ranged between 0.996 and 0.999 for the arsenic and selenium species. Column recovery for ion chromatography was calculated to be 97 {+-} 6% for combined arsenic species and 98 {+-} 3% for combined selenium species. Because certified reference materials for As and Se speciation studies are still not commercially available, in order to check accuracy and precision the method was applied to certified reference materials, BCR 714, BCR 1714, and BCR 715 and to two different refinery samples - inlet and outlet wastewater. The method was successfully used to study the quantitative speciation of selenium and arsenic in petroleum refinery wastewaters. (orig.)

  11. Clinical experience with 75Se selenomethylcholesterol adrenal imaging

    International Nuclear Information System (INIS)

    Shapiro, B.; Britton, K.E.; Hawkins, L.A.; Edwards, C.R.W.

    1981-01-01

    The results of quantitative adrenal imaging using 75 Se selenomethylcholesterol in sixty-two subjects are analysed. The adrenal area was localized by a renal scan, lateral views of which enabled adrenal depth to be estimated. The first nineteen cases were scanned with a rectilinear scanner and the remaining forty-three cases imaged with a gamma camera. Quantitation of adrenal uptake was performed on computer-stored static images obtained 7 and 14 days post-injection of 75 Se selenomethylcholesterol (3 and 6 days in the first ten cases studied). Normal uptake was found to be 0.07-0.30% of the administered dose. Overall predictive accuracy of the type of adrenal disorder of thirty-two patients with Cushing's syndrome was 90.6%. Overall predictive accuracy of the cause of Conn's syndrome in twenty-two cases was 86.4%. The mean uptake in the normal adrenal in cases of unilateral adenoma was 0.19% (range 0.07-0.30%). Causes of unsatisfactory adrenal imaging are examined. The procedure is recommended as the localizing and lateralizing technique of choice in Cushing's syndrome except where due to adrenal carcinoma, and as an important non-invasive technique in Conn's syndrome for the lateralization of adenoma. (author)

  12. In situ observation of the formation of FeSe

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Wulff, Anders Christian; Yue, Zhao

    2011-01-01

    The formation of the FeSe compound from a mixture of Fe and Se powders encased in a composite Cu/Nb sheath was studied in situ by means of high-energy synchrotron x-ray diffraction. Tetragonal beta-FeSe does not seem to form directly from the starting elements. Instead, a sequence of FeSe2, Fe3Se...

  13. CIGS thin films, solar cells, and submodules fabricated using a rf-plasma cracked Se-radical beam source

    International Nuclear Information System (INIS)

    Ishizuka, Shogo; Yamada, Akimasa; Shibata, Hajime; Fons, Paul; Niki, Shigeru

    2011-01-01

    Coevaporated Cu(In,Ga)Se 2 (CIGS) film growth using a rf-plasma cracked Se-radical beam (R-Se) source leads to a significant reduction in the amount of raw Se source material wasted during growth and exhibits unique film properties such as highly dense, smooth surfaces and large grain size. R-Se grown CIGS solar cells also show concomitant unique properties different from conventional evaporative Se (E-Se) source grown CIGS cells. In the present work, the impact of modified surfaces, interfaces, and bulk crystal properties of R-Se grown CIGS films on the solar cell performance was studied. When a R-Se source was used, Na diffusion into CIGS layers was enhanced while a remarkable diffusion of elemental Ga and Se into Mo back contact layers was observed. Improvements in the bulk crystal quality as manifested by large grain size and increased Na concentration with the use of a R-Se source is expected to be effective to improve photovoltaic performance. Using a R-Se source for the growth of CIGS absorber layers at a relatively low growth temperature, we have successfully demonstrated a monolithically integrated submodule efficiency of 15.0% (17 cells, aperture area of 76.5 cm 2 ) on 0.25-mm thick soda-lime glass substrates.

  14. American Indian/ Alaska Native Area/ Hawaiian Homeland Areas for San Juan County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  15. Benefits of oxygen in CuInSe{sub 2} and CuGaSe{sub 2} containing Se-rich grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Chunbao, E-mail: chunbaofeng@126.com [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Luo, Min; Li, Bolin; Li, Dengfeng [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China); Nie, Jinlan [Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu, 610054 (China); Dong, Huining [Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, Chongqing, 400065 (China)

    2014-05-01

    Using density functional theory calculation, we show that oxygen (O) exhibits an interesting effect in CuInSe{sub 2} and CuGaSe{sub 2}. The Se atoms with dangling bonds in a Se-rich Σ3 (114) grain boundary (GB) create deep gap states due to strong interaction between Se atoms. However, when such a Se atom is substituted by an O atom, the deep gap states can be shifted into valence band, making the site no longer a harmful non-radiative recombination center. We find that O atoms prefer energetically to substitute these Se atoms and induce significant lattice relaxation due to their smaller atomic size and stronger electronegativity, which effectively reduces the anion–anion interaction. Consequently, the deep gap states are shifted to lower energy regions close or even below the top of the valence band.

  16. Phase diagram of SnTe-CdSe cross-section of SnTe+CdSe reversible SnSe+CdTe ternary reciprocal system

    International Nuclear Information System (INIS)

    Dubrovin, I.V.; Budennaya, L.D.; Mizetskaya, I.B.; Sharkina, Eh.V.

    1986-01-01

    Phase equilibrium diagram of SnTe-CdSe cross-section of Sn, Cd long Te, Se ternary reciprocal system is investigated using the methods of differential thermal, X-ray phase, and microstructural analyses. Maximum length of solid solutions on the base of SnTe corresponds to approximately 14 mol.% at 1050 K and approximately 3 mol.% of CdSe at 670 K. Region of solid solutions on the base of CdSe corresponds to less than 1 mol.% of SnTe at room temperature. SnTe-CdSe cross-section is not a quasibinar one. Equilibrium is shifted to the left in the SnTe+CdSe reversible SnSe+CdTe reciprocal system

  17. Mantle structure and tectonic history of SE Asia

    Science.gov (United States)

    Hall, Robert; Spakman, Wim

    2015-09-01

    Seismic travel-time tomography of the mantle under SE Asia reveals patterns of subduction-related seismic P-wave velocity anomalies that are of great value in helping to understand the region's tectonic development. We discuss tomography and tectonic interpretations of an area centred on Indonesia and including Malaysia, parts of the Philippines, New Guinea and northern Australia. We begin with an explanation of seismic tomography and causes of velocity anomalies in the mantle, and discuss assessment of model quality for tomographic models created from P-wave travel times. We then introduce the global P-wave velocity anomaly model UU-P07 and the tectonic model used in this paper and give an overview of previous interpretations of mantle structure. The slab-related velocity anomalies we identify in the upper and lower mantle based on the UU-P07 model are interpreted in terms of the tectonic model and illustrated with figures and movies. Finally, we discuss where tomographic and tectonic models for SE Asia converge or diverge, and identify the most important conclusions concerning the history of the region. The tomographic images of the mantle record subduction beneath the SE Asian region to depths of approximately 1600 km. In the upper mantle anomalies mainly record subduction during the last 10 to 25 Ma, depending on the region considered. We interpret a vertical slab tear crossing the entire upper mantle north of west Sumatra where there is a strong lateral kink in slab morphology, slab holes between c.200-400 km below East Java and Sumbawa, and offer a new three-slab explanation for subduction in the North Sulawesi region. There is a different structure in the lower mantle compared to the upper mantle and the deep structure changes from west to east. What was imaged in earlier models as a broad and deep anomaly below SE Asia has a clear internal structure and we argue that many features can be identified as older subduction zones. We identify remnants of slabs

  18. The distribution and habitat requirements of the genus Orobanche L. (Orobanchaceae in SE Poland

    Directory of Open Access Journals (Sweden)

    Renata Piwowarczyk

    2011-05-01

    Full Text Available The distribution of the genus Orobanche in SE Poland is presented. The study area stretches between the Vistula and the Bug rivers, and comprises the Polish areas of the Lublin-Lwów Upland, the Wołyń Upland and the southern part of Polesie. Eight species of the genus Orobanche: O. alba, O. alsatica, O. arenaria, O. caryophyllacea, O. elatior, O. lutea, O. pallidiflora, O. picridis, were collected during floristic investigations conducted between 1999 and 2010. The hosts, abundance and habitat preferences at the localities are given and a supplemented map of the distribution in SE Poland is included.

  19. Uma vida que se esvai no Parkinson

    Directory of Open Access Journals (Sweden)

    Eliane Michelini Marraccini

    Full Text Available A doença de Parkinson é uma síndrome neurológica de evolução lenta e progressiva que emerge na idade madura e velhice. A crescente debilitação física contrasta com a manutenção da integridade mental, na maioria dos pacientes até o fim da vida. Nessa enfermidade incurável, que costuma perdurar por longos anos, surgem importantes reações físicas diante da progressiva incapacitação, com profundos reflexos na subjetividade do paciente. Este trabalho refere-se ao atendimento de uma paciente, acompanhada em seu processo de conscientização e elaboração da irreversibilidade da doença. Ao final,é ressaltada a intrínseca articulação somatopsíquica, com destaque para a depressão na acentuação dos sintomas parkinsonianos.

  20. A study on landscape and the historical geography of two areas - Oskarshamn and Forsmark

    International Nuclear Information System (INIS)

    Jansson, Ulf; Berg, Johan; Bjoerklund, Annika

    2004-06-01

    The aim of this project is to investigate the land-use; the settlement and the way people have used and affected the landscape in two areas, Forsmark and Simpevarp. This preliminary report aim mainly at describing the sources and methods used in the project. Some analyses are undertaken, but a more complete interpretation will take place in the final report of Phase two. This is a project that forms a part of the environmental impact assessment work that is done for examining potential locations for a plant for a deep repository for spent nuclear fuel. Both areas are located on the East Coast of Sweden. A number of scientific studies are carried out in this project. Fields that are included studies for the EIA and the safety assessment include geology, quaternary geology, limnology, biology and other natural sciences that focus on vegetation and the terrestrial as well as the aquatic environment.The study that is carried out at the Department of Human geography at Stockholm university is basically a study of the historical land-use, the changes in settlement and how people have been working and using the landscape over the last centuries.The methods used include historical maps, cadastral material and in a later phase interviews and fieldwork. In the first phase that ends the summer 2004 the bulk of the historical material is probed and analysed. A big effort is put into the creation of GIS-data sets that can be used for further analyses. The work during spring 2004 resulted in this preliminary report that deal with historical land-use, population, settlement from medieval times to the present and both detailed and general descriptions and investigations of the historical geography of the areas.Both the investigated areas are located by the Baltic, but are very different both physically, especially with the land upheaval in the north, and historically with a different land-use system, ownership structure and distribution of settlement. The results of this study

  1. A study on landscape and the historical geography of two areas - Oskarshamn and Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Ulf; Berg, Johan; Bjoerklund, Annika [Stockholm Univ. (Sweden). Dept. of Human Geography

    2004-06-01

    The aim of this project is to investigate the land-use; the settlement and the way people have used and affected the landscape in two areas, Forsmark and Simpevarp. This preliminary report aim mainly at describing the sources and methods used in the project. Some analyses are undertaken, but a more complete interpretation will take place in the final report of Phase two. This is a project that forms a part of the environmental impact assessment work that is done for examining potential locations for a plant for a deep repository for spent nuclear fuel. Both areas are located on the East Coast of Sweden. A number of scientific studies are carried out in this project. Fields that are included studies for the EIA and the safety assessment include geology, quaternary geology, limnology, biology and other natural sciences that focus on vegetation and the terrestrial as well as the aquatic environment.The study that is carried out at the Department of Human geography at Stockholm university is basically a study of the historical land-use, the changes in settlement and how people have been working and using the landscape over the last centuries.The methods used include historical maps, cadastral material and in a later phase interviews and fieldwork. In the first phase that ends the summer 2004 the bulk of the historical material is probed and analysed. A big effort is put into the creation of GIS-data sets that can be used for further analyses. The work during spring 2004 resulted in this preliminary report that deal with historical land-use, population, settlement from medieval times to the present and both detailed and general descriptions and investigations of the historical geography of the areas.Both the investigated areas are located by the Baltic, but are very different both physically, especially with the land upheaval in the north, and historically with a different land-use system, ownership structure and distribution of settlement. The results of this study

  2. Determination of total, and bound Se in sera by INAA

    International Nuclear Information System (INIS)

    Spate, V.L.; Mason, M.M.; Reams, C.L.; Baskett, C.K.; Morris, J.S.; Mills, D.S.

    1994-01-01

    The comparison between the total selenium in serum ('total Se') with that which is apparently bound to high molecular weight (> 12.000 D) species, presumably proteins ('bound Se') was reported. Nine hundred seventy seven (977) serum samples arising out of a population-based epidemiological study were prepared in duplicate for the determination of 'total Se' by pipeting directly into irradiation vials; and separate duplicate aliquots were dialyzed against DI water for the determination of 'bound Se'. All samples were analyzed by neutron activation analysis via 77m Se (17.4s) A small dialyzable Se component (∼ 6%) ('free Se'), defined as the difference between the 'total Se' minus the 'bound Se', was identified. (author) 2 refs.; 3 figs.; 5 tabs

  3. Revitalization Areas

    Data.gov (United States)

    Department of Housing and Urban Development — Revitalization areas are HUD-designated neighborhoods in need of economic and community development and where there is already a strong commitment by the local...

  4. 700 Area

    Data.gov (United States)

    Federal Laboratory Consortium — The 700 Area of the Hanford Site is located in downtown Richland.Called the Federal Office Building, the Richland Operations Site Manager and the Richland Operations...

  5. Alternative syntheses of [73,75Se]selenoethers exemplified for homocysteine[73,75Se]selenolactone

    International Nuclear Information System (INIS)

    Ermert, J.; Blum, T.; Hamacher, K.; Coenen, H.H.

    2001-01-01

    The present work describes two radiosynthetic pathways to prepare homocysteine[ 75 Se]selenolactone 1 starting from n.c.a. [ 75 Se]selenite 2. It was achieved either by alkylation reaction of n.c.a. methyl[ 75 Se]selenide 4 or by hydrolysis of alkylated 1,3-dicyclohexyl[ 75 Se]selenourea 11. N.c.a. methyl[ 75 Se]selenide 4 is available using sulfur as non-isotopic carrier. However, the radiochemical yield of the substitution of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 with n.c.a. methyl-[ 75 Se]selenide is only in the range of 15%-20%. Birch reduction of protected n.c.a. [ 75 Se]selenomethionine 6 formed leads to a RCY of 5%-10% homocysteine[ 75 Se]selenolactone 1. Alternatively, the synthesis of homocysteine[ 75 Se]selenolactone 1 is possible by hydrolysis of the corresponding [ 75 Se]selenouronium salt 11 available by addition of 2-tert.-butoxycarbonylamino-4-bromobutyric acid ethylester 5 to 1,3-dicyclohexyl[ 75 Se]selenourea 10. A method was developed for the synthesis of 1,3-dicyclohexyl[ 75 Se]selenourea 10 by addition of c.a. [ 75 Se]SeH 2 to 1,3-dicyclohexylcarbodiimide, which leads to 20%-30% RCY of c.a. homocysteine[ 75 Se]selenolactone 1. (orig.)

  6. Current Urban Areas for Santa Fe County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  7. 2000 Census Urban Areas for Los Alamos County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  8. Current 5-Digit ZIP Code Tabulation Areas (ZCTAs) for Quay County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  9. Current Urban Areas for Luna County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  10. Current Core Based Statistical Areas for Chaves County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  11. 2000 Census Public Use Microdata Area (PUMA) 1% for Chaves County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  12. 2000 Census Public Use Microdata Area (PUMA) 1% for Sandoval County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  13. American Indian Tribal Subdivision Areas for Socorro County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  14. 2000 Census Metropolitan Statistical Areas (MSA) for Sandoval County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  15. American Indian Tribal Subdivision Areas for Sandoval County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  16. American Indian Tribal Subdivision Areas for Bernalillo County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  17. 2000 Census Public Use Microdata Area (PUMA) 5% for Hidalgo County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  18. 2000 Census Public Use Microdata Area (PUMA) 1% for Catron County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  19. 2000 Census Public Use Microdata Area (PUMA) 1% for Otero County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  20. Current 3-Digit ZIP Code Tabulation Areas (ZCTAs) for Guadalupe County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  1. Current Urban Areas for Hidalgo County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  2. 2000 Census Public Use Microdata Area (PUMA) 5% for Sandoval County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  3. Current 3-Digit ZIP Code Tabulation Areas (ZCTAs) for Union County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  4. 2000 Census Public Use Microdata Area (PUMA) 5% for Otero County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  5. 2000 Census Public Use Microdata Area (PUMA) 5% for Mora County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  6. Current 3-Digit ZIP Code Tabulation Areas (ZCTAs) for Torrance County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  7. Current Combined Statistical Areas for Curry County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  8. Current 3-Digit ZIP Code Tabulation Areas (ZCTAs) for Sierra County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  9. Current Urban Areas for Lincoln County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  10. American Indian Tribal Subdivision Areas for San Juan County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  11. Current 5-Digit ZIP Code Tabulation Areas (ZCTAs) for Guadalupe County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  12. Current Urban Areas for Cibola County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  13. Current Core Based Statistical Areas for Los Alamos County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  14. American Indian Tribal Subdivision Areas for Rio Arriba County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  15. Current 5-Digit ZIP Code Tabulation Areas (ZCTAs) for Valencia County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  16. Current 3-Digit ZIP Code Tabulation Areas (ZCTAs) for Roosevelt County, New Mexico, 2006se TIGER

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — The 2006 Second Edition TIGER/Line files are an extract of selected geographic and cartographic information from the Census TIGER database. The geographic coverage...

  17. Structure and optical properties of GaSe-CdSe composites driven by Cd intercalation in GaSe lamellar crystals

    International Nuclear Information System (INIS)

    Caraman, Iuliana; Kantser, Valeriu; Evtodiev, Igor; Untila, Dumitru; Dmitroglo, Liliana; Leontie, Liviu; Arzumanyan, Grigory

    2015-01-01

    A new composite material composed of GaSe and CdSe has been obtained by treatment of GaSe single-crystal lamellas in Cd vapors at temperatures of 773-853 K and intercalation of Cd interlayers. The structure and optical properties of the GaSe-CdSe composite material have been studied. The content of CdSe crystallites was found to grow with increasing treatment temperature or with increasing duration of treatment at a constant temperature. Analysis of XRD, PL, XPS, AFM, and Raman patterns has shown that the heterogeneous composite composed of micro and nanocrystallites of CdSe in GaSe can be obtained by Cd intercalation in a temperature range of 753-853 K. On the basis of Raman spectrum, the vibrational modes of the composite have been identified. The PL of these materials contains emission bands of free and bound excitons, donor-acceptor bands, and bands of recombination via impurity levels. The PL emission spectra measured at a temperature of 78 and 300 K for the composites result from the overlapping of the emission bands of the components of GaSe doped with Cd and the CdSe crystallites. (authors)

  18. The influence of CdSe and ZnSe nanoparticles on the optical properties of Sm"3"+ ions in lead borate glasses

    International Nuclear Information System (INIS)

    Mallur, Saisudha B.; Heidorn, William D.; Fatokun, Stephen O.; Joshi, Krishna D.; Bista, Sandip S.; Babu, Panakkattu K.

    2017-01-01

    The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B_2O_3:0.5Sm_2O_3, x = 29.5–69.5 mol%, xPbO:(96.5-x) B_2O_3:0.5Sm_2O_3: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σ_p), and the area ratio of the electric dipole/magnetic dipole transitions of Sm"3"+. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σ_p for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σ_p when the average particle size is ~16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm"3"+ in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σ_p values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications.

  19. The influence of CdSe and ZnSe nanoparticles on the optical properties of Sm{sup 3+} ions in lead borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mallur, Saisudha B.; Heidorn, William D.; Fatokun, Stephen O.; Joshi, Krishna D.; Bista, Sandip S.; Babu, Panakkattu K., E-mail: PK-Babu@wiu.edu [Western Illinois University, Department of Physics (United States)

    2017-03-15

    The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B{sub 2}O{sub 3}:0.5Sm{sub 2}O{sub 3}, x = 29.5–69.5 mol%, xPbO:(96.5-x) B{sub 2}O{sub 3}:0.5Sm{sub 2}O{sub 3}: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σ{sub p}), and the area ratio of the electric dipole/magnetic dipole transitions of Sm{sup 3+}. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σ{sub p} for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σ{sub p} when the average particle size is ~16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm{sup 3+} in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σ{sub p} values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications.

  20. Synthesis of selenium/EDTA-derived porous carbon composite as a Li–Se battery cathode

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chenhao, E-mail: zhaochenhao123456@163.com; Fang, Shuzhen; Hu, Zhibiao, E-mail: zhibiaohu@163.com; Qiu, Sheng’en; Liu, Kaiyu [LongYan University, College of Chemistry & Materials Science (China)

    2016-07-15

    The carbon substrate with unique 3D macroporous structure has been prepared through the immediate carbonization of ethylenediaminetetraacetic acid (EDTA) and KOH mixture. The porous carbon composed of micro- and small mesoporous (2–5 nm) structure has a BET specific surface area of 1824.8 m{sup 2} g{sup −1}. The amorphous and nanosized Se is uniformly encapsulated into the porous structure of porous carbon using melting diffusion route, and the weight content of Se in target Se/C composite can be as high as ~50 %. As an Li–Se battery cathode, the Se/C composite delivers a reversible (2nd) discharge capacity of 597.4 mAh g{sup −1} at 0.24C and retains a discharge capacity of 538.4 mAh g{sup −1} at 0.24C after 100 cycles. Furthermore, the composite also has a stable capacity of 291.0 mAh g{sup −1} at a high current of 4.8C. The high specific area and good porous size of EDTA-derived carbon substrate may a be responsibility for the excellent electrochemical performances of Se/C composite.

  1. Low-Temperature Deposition of Layered SnSe2 for Heterojunction Diodes

    KAUST Repository

    Serna, Martha I.

    2018-04-27

    Tin diselenide (SnSe) has been recently investigated as an alternative layered metal dichalcogenide due to its unique electrical and optoelectronics properties. Although there are several reports on the deposition of layered crystalline SnSe films by chemical and physical methods, synthesis methods like pulsed laser deposition (PLD) are not reported. An attractive feature of PLD is that it can be used to grow 2D films over large areas. In this report, a deposition process to grow stoichiometric SnSe on different substrates such as single crystals (Sapphire) and amorphous oxides (SiO and HfO) is reported. A detailed process flow for the growth of 2D SnSe at temperatures of 300 °C is presented, which is substantially lower than temperatures used in chemical vapor deposition and molecular beam epitaxy. The 2D SnSe films exhibit a mobility of ≈4.0 cm V s, and are successfully used to demonstrate SnSe/p-Si heterojunction diodes. The diodes show I /I ratios of 10-10 with a turn on voltage of <0.5 V, and ideality factors of 1.2-1.4, depending on the SnSe film growth conditions.

  2. Chemical synthesis of Cu2Se nanoparticles at room temperature

    International Nuclear Information System (INIS)

    Rong, Fengxia; Bai, Yan; Chen, Tianfeng; Zheng, Wenjie

    2012-01-01

    Graphical abstract: The Cu 2 Se nanoparticles were synthesized by a simple and rapid method at room temperature. The TEM and SEM images show that the Cu 2 Se nanoparticles were spherical. Highlights: ► Cu 2 Se nanoparticles were synthesized by the reaction of nanoSe 0 sol with Cu + ions. ► The Cu 2 Se nanoparticles were spherical with cubic structure and well crystallized. ► Optical and electrochemical properties of Cu 2 Se nanoparticles were observed. ► The formation mechanism of Cu 2 Se nanoparticles was proposed. -- Abstract: A simple and rapid method has been developed to synthesize cuprous selenide (Cu 2 Se) nanoparticles by the reaction of selenium nanoparticles sol with copper sulfate solution containing ascorbic acid at room temperature. Cu 2 Se nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray analysis (EDX). The results indicated that Cu 2 Se nanoparticles were cubic crystal structure and spherical with the diameter about 75 nm. The ultraviolet–visible absorption spectrum (UV–vis) and cyclic voltammetry of Cu 2 Se nanoparticles were also investigated. The optical band gap energy of Cu 2 Se nanoparticles was 1.94 eV. On the basis of a series of experiments and characterizations, the formation mechanism of Cu 2 Se nanoparticles was discussed.

  3. La desaceleración económica colombiana: se cosecha lo que se siembra

    Directory of Open Access Journals (Sweden)

    Carlos Humberto Ortiz

    2009-12-01

    Full Text Available La desaceleración económica que experimenta Colombia desde 1980 se explica por el estancamiento estructural de la economía y por la escalada de violencia relacionada con la expansión del narcotráfico. Los datos disponibles no rechazan esta hipótesis. El artículo plantea que la desindustrialización y el narcotráfico se forjaron en el mismo crisol: un modelo de desarrollo que ha integrado progresivamente la economía nacional a los mercados mundiales al tiempo que ha renunciado, también progresivamente, a la opción industrialista. Además, argumenta que la explosión del narcotráfico obedece a la profundización de la guerra contra las drogas en un contexto de demanda mundial creciente e inelástica.

  4. SE-72/AS-72 generator system based on Se extraction/ As reextraction

    Science.gov (United States)

    Fassbender, Michael Ernst; Ballard, Beau D

    2013-09-10

    The preparation of a .sup.72Se/.sup.72As radioisotope generator involves forming an acidic aqueous solution of an irradiated alkali bromide target such as a NaBr target, oxidizing soluble bromide in the solution to elemental bromine, removing the elemental bromine, evaporating the resulting solution to a residue, removing hydrogen chloride from the residue, forming an acidic aqueous solution of the residue, adding a chelator that selectively forms a chelation complex with selenium, and extracting the chelation complex from the acidic aqueous solution into an organic phase. As the .sup.72Se generates .sup.72As in the organic phase, the .sup.72As may be extracted repeatedly from the organic phase with an aqueous acid solution.

  5. Optical band gap study of a-Se and Se-Sb thin films

    International Nuclear Information System (INIS)

    Kaur, Ramandeep; Singh, Palwinder; Thakur, Anup

    2016-01-01

    Amorphous selenium (a-Se) and a-Se_9_5Sb_5 alloy were prepared using melt quenching technique. X-ray diffraction (XRD) pattern confirmed the amorphous nature of the prepared samples. Composition of the prepared samples has been determined using Energy dispersive X-ray fluorescence (EDXRF) technique. Differential thermal analysis (DTA) confirmed the glassy nature of the prepared samples. Thin films of the prepared samples were deposited on glass substrate using thermal evaporation method. Amorphous nature of the deposited films was confirmed using XRD. Optical properties of these films were obtained from the UV-VIS transmission spectra, at normal incidence, over 200-1100 nm spectral range. The optical absorption edge was described by using the model given by the Tauc. Optical band gap of the deposited films was calculated using Tauc plot. Optical characterization showed that average transmission and optical band gap decreased with the addition of antinomy.

  6. Por uma cidade que se move e se comunica: corpo, rua e improviso

    Directory of Open Access Journals (Sweden)

    Julia Saldanha Vieira de Aguiar

    2009-06-01

    Full Text Available Este trabalho trata da relação de um lugar com suas pessoas. A reflexão acontece a partir de um estudo de caso: o Camelódromo da Praça XV. O Camelódromo foi uma grande feira, que durante 40 anos ocupou um espaço importante no centro de Porto Alegre/RS. (Auto organizado e vivido principalmente pelo povo, o fenômeno se configurava em um lugar onde improviso e estética constituiam o modo de ser e agir no cotidiano da rua. Ironicamente, no início de 2009, o Camelódromo foi transferido para dentro de um prédio. Hoje, onde se desenrolava o espetáculo do imprevisível, encontra-se um estacionamento para carros. Este trabalho foi produzido nos últimos meses do Camelódromo; em um espírito de elogio à estética do improviso e à auto-organização. Buscamos articular idéias da teoria da complexidade, do urbanismo, das artes e da comunicação, para tentar compreender um pouco essa manifestação espontânea, tão característica da urbe no século XXI.

  7. Expression and crystallization of SeDsbA, SeDsbL and SeSrgA from Salmonella enterica serovar Typhimurium

    International Nuclear Information System (INIS)

    Jarrott, R.; Shouldice, S. R.; Gunčar, G.; Totsika, M.; Schembri, M. A.; Heras, B.

    2010-01-01

    The cloning, purification, crystallization and preliminary crystallographic studies of three DsbA-like proteins present in S. enterica serovar Typhimurium, SeDsbA, SeDsbL and SeSrgA, are reported. Pathogens require protein-folding enzymes to produce functional virulence determinants. These foldases include the Dsb family of proteins, which catalyze oxidative folding in bacteria. Bacterial disulfide catalytic processes have been well characterized in Escherichia coli K-12 and these mechanisms have been extrapolated to other organisms. However, recent research indicates that the K-12 complement of Dsb proteins is not common to all bacteria. Importantly, many pathogenic bacteria have an extended arsenal of Dsb catalysts that is linked to their virulence. To help to elucidate the process of oxidative folding in pathogens containing a wide repertoire of Dsb proteins, Salmonella enterica serovar Typhimurium has been focused on. This Gram-negative bacterium contains three DsbA proteins: SeDsbA, SeDsbL and SeSrgA. Here, the expression, purification, crystallization and preliminary diffraction analysis of these three proteins are reported. SeDsbA, SeDsbL and SeSrgA crystals diffracted to resolution limits of 1.55, 1.57 and 2.6 Å and belonged to space groups P2 1 , P2 1 2 1 2 and C2, respectively

  8. Electrodeposition of epitaxial CdSe on (111) gallium arsenide

    Energy Technology Data Exchange (ETDEWEB)

    Cachet, H.; Cortes, R.; Froment, M. [Universite Pierre et Marie Curie, Paris (France). Phys. des Liquides et Electrochimie; Etcheberry, A. [Institut Lavoisier (IREM) UMR CNRS C0173, Universite de Versailles- St Quentin en Yvelynes, 45 Avenue des Etats Unis, 78035, Versailles (France)

    2000-02-21

    Epitaxial growth of CdSe has been achieved on GaAs(111) by electrodeposition from an aqueous electrolyte. The structure of the film corresponds to the cubic modification of CdSe. The quality of epitaxy has been investigated by reflection high energy electron diffraction, transmission electron microscopy and X-ray diffraction techniques. By XPS measurements the chemistry of the CdSe/GaAs interface and the composition of CdSe are determined. (orig.)

  9. Charge confinements in CdSe-ZnSe symmetric double quantum wells

    International Nuclear Information System (INIS)

    Tit, Nacir; Obaidat, Ihab M

    2008-01-01

    The bound states in the (CdSe) N w (ZnSe) N b (CdSe) N w -ZnSe(001) symmetric double quantum wells are investigated versus the well width (N w ) and the barrier thickness (N b ). A calculation based on the sp 3 s * tight-binding method which includes the spin-orbit interactions is employed to calculate the bandgap energy, quantum-confinement energy, and band structures. The studied systems possess a vanishing valence-band offset (VBO = 0) in consistency with the well known common-anion rule, and a large conduction-band offset (CBO ≅ 1 eV), which plays an essential role in the confinement of electrons within the CdSe wells. The biaxial strain, on the other hand, plays another role in confining the holes at the interfaces (within the well regions) and thus enhancing the radiative efficiency. The induced-strain energy is estimated to be ∼35 meV. More importantly, the results show that, for a fixed barrier thickness, the double wells are able to confine a pair of bound states when they are very thin. By increasing the wells' width (N w ), further, a new pair of states from the conduction-band continuum falls into the wells every time N w hits a multiple of four monolayers (more specifically, for 4n w ≤4(n+1), the number of bound states is 2(n+1), where n is an integer). On the other hand, the barrier thickness (N b ) is shown to have no effect on the number of bound states, but it solely controls their well-to-well interactions. A critical barrier thickness to switch off these latter interactions is estimated to occur at about N crit b ≅ 9 (L crit b ≅ 25∼AA. Rules governing the variation of the quantum-confinement energy versus both barrier thickness (N b ) and well width (N w ) have been derived. Our theoretical results are also shown to have excellent agreement with the available experimental photoluminescence data

  10. Complementary information on CdSe/ZnSe quantum dot local structure from extended X-ray absorption fine structure and diffraction anomalous fine structure measurements

    International Nuclear Information System (INIS)

    Piskorska-Hommel, E.; Holý, V.; Caha, O.; Wolska, A.; Gust, A.; Kruse, C.; Kröncke, H.; Falta, J.; Hommel, D.

    2012-01-01

    The extended X-ray absorption fine structure (EXAFS) and diffraction anomalous fine structure (DAFS) have been applied to investigate a local structure for the CdSe/ZnSe quantum dots grown by molecular beam epitaxy (MBE) and migration-enhanced epitaxy (MEE). The aim was to study the intermixing of Cd and Zn atoms, chemical compositions and strain induced by cap-layer. The EXAFS at the Cd K-edge and DAFS at the Se K-edge proved the intermixing of Cd and Zn atoms. The distances Cd–Se (2.61 Å) found from EXAFS and DAFS analysis for h 1 region is closer to that in bulk CdSe (2.62 Å). The DAFS analysis revealed the differences in the local structure in two investigated regions (i.e. different iso-strain volumes) on the quantum dots. It was found that the investigated areas differ in the Cd concentration. To explain the experimental results the theoretical calculation based on a full valence-force field (VFF) model was performed. The theoretical VFF model fully explains the experimental data.

  11. Die tema van God se spraak in Hebreërs se inleidingsformules

    Directory of Open Access Journals (Sweden)

    Albert J. Coetsee

    2015-03-01

    Full Text Available Alhoewel die voorkoms en gebruik van die Ou Testament in die meeste navorsing oor Hebreërs besonder baie aandag geniet, is dit nie die geval met die Hebreërskrywer se gebruik van inleidingsformules vir sy Ou-Testamentiese aanhalings nie. Die gevolg is dat daar tot op hede betreklik min selfstandige navorsing oor die Hebreërskrywer se tema van God se spraak by sy inleidingsformules gedoen is. In hierdie artikel word Hebreërs se inleidingsformules in besonderhede nagegaan om te bepaal wat die aard en inhoud van die Hebreërskrywer se verwysings na die tema van God se spraak in sy inleidingsformules is. Daar word onder andere bepaal dat Hebreërs 38 direkte aanhalings vanuit die Ou Testament bevat, dat die Hebreërskrywer, met slegs een uitsondering, elke inleidingsformule met ’n werkwoord van sêinlei, dat ’n Persoon van die Drie-eenheid in 34 van die 38 direkte aanhalings (± 89% die onderwerp en gevolglike Spreker van die Ou-Testamentiese woorde is, dat die Hebreërskrywer al drie Persone van die Drie-eenheid as God beskou, en dat die Hebreërskrywer oortuig is dat die Ou Testament geïnspireer is en God se geldige en relevante openbaring bly. The theme of God’s speech in Hebrews’ introduction formulae. Whilst the occurance and function of the Old Testament in research on Hebrews enjoys a lot of attention, this is not the case for the writer of Hebrews’ use of introduction formulae for his Old Testament quotations. The result is that up to date relatively few independent studies have been made on the writer of Hebrews’ theme of God’s speech in his introduction formulae. In this article the introduction formulae in Hebrews are researched in detail to determine the nature and content of the writer of Hebrews’ reference to the theme of God’s speech in his introduction formulae. Amongst other things it is determined that Hebrews has 38 direct quotations from the Old Testament, that with the exception of one

  12. Electronic structure and magnetic properties of KCrSe2

    NARCIS (Netherlands)

    Fang, C.M.; Tolsma, P.R.; Groot, R.A. de; Wiegers, G.A.; Haas, C.; vanBruggen, C.F.; deGroot, R.A.

    1996-01-01

    KCrSe2 characterized by x-ray powder diffraction is a layered compound isostructural with NaCrSe2: a = 3.80 Angstrom; c = 22.19 Angstrom; space group R (3) over bar m. The magnetic properties are similar to those of NaCrSe2 but with ari even more pronounced difference between the intralayer and

  13. Luminescence of nanocrystalline ZnSe:Mn2+

    NARCIS (Netherlands)

    Suyver, J.F.; Wuister, S.F.; Kelly, J.J.; Meijerink, A.

    2000-01-01

    The luminescence properties of nanocrystalline ZnSe:Mn^(2+) prepared via an inorganic chemical synthesis are described. Photoluminescence spectra show distinct ZnSe and Mn^(2+) related emissions, both of which are excited via the ZnSe host lattice. The Mn^(2+) emission wavelength and the

  14. Annealing effect on I-V characteristic of n-ZnO-p-InSe heterojunction

    Directory of Open Access Journals (Sweden)

    Kovalyuk Z. D.

    2015-12-01

    Full Text Available The article is devoted to studying of influence of vacuum low-temperature annealing on the electrical and photoelectric characteristics of n-ZnO-p-InSe heterostructure. Indium monoselenide (InSe is a semiconductor of the A3B6 group of layered compounds. The basic unit consists of two planes of metal atoms sandwiched between two planes of chalcogen atoms (Se-In-In-Se. The absence of dangling bonds on InSe cleaved surface makes it possible to use this semiconductor as a substrate for fabrication of heterostructures based on semiconductor materials with different symmetries and lattice spacings. Zinc oxide (ZnO is the most suitable material for window materials and solar cells buffer layers application due to its marvelous transparency in the range of visible region. InSe single crystals were grown by the Bridgman technique from a nonstoichiometric melt and characterized by a pronounced layered structure along the whole length of a sample. ZnO thin oxide film was formed on freshly cleaved van der Waals surface of InSe layered crystal. n-ZnO-p-InSe heterostructure was prepared by the method of high-frequency magnetron sputtering. Sensitivity spectral areas were identified by MDR-3 monochromator with a resolution of 2.6 nm/mm. The current-voltage characteristics of the n-ZnO-p-InSe heterostructures showed a clearly pronounced diode character. In the forward bias of the initial samples, the diode factor had the value 3.7 at room temperature. It is shown that vacuum low-temperature annealing reduces shunt currents of the heterojunction, which is reflected in the decrease in the values of n from 3.7 to 2.7.

  15. Optimal parameter selection for qualitative regional erosion risk monitoring: A remote sensing study of SE Ethiopia

    Directory of Open Access Journals (Sweden)

    Moncef Bouaziz

    2011-04-01

    Maps derived from this qualitative analysis allow the identification and ranking of erosion intensity. These maps enable us to highlight areas in immediate need of conservation strategies in order to control siltation of the SE Ethiopian reservoir and to control further soil degradation.

  16. Paleoseismological study on stone cultural sites in Gyeongju, SE Korea

    Science.gov (United States)

    Lee, M.; Jin, K.; Kim, Y.

    2008-12-01

    The Korean peninsular, located within the Eurasian intracontinental region, is presently considered to be tectonically safe compared with neighboring countries such as Japan and Taiwan. However, historical records for the Gyeongju area, which is an old capital city with many ancient stone buildings, demonstrate that seismic events have significantly affected lives and properties in this town. For example, one reported earthquake in 779 AD had an inferred magnitude of M=6.7 and resulted in the deaths of over a hundred people and the destruction of many buildings. This study examines the affects of paleoseismological events recorded by stone constructions in Gyeongju. The study area contains mostly granite and is located near the junction between the Yangsan and Ulsan faults, which represent two of the major faults in SE Korea. In May of 2007, a statue of Buddha that was previously attached to and carved from a vertical granite cliff was discovered resting on the 45° slope of the Yeolam valley. Based on the artistic style of the granite statue, it was estimated to be during the late 8th century; it has a weight of about 70 tons and dimensions of 250x190x620 cm. Four main joint directions exist in the statue and in granite exposed in the cliff at its original location. These joint sets match if the statue were rotated 15° clockwise back from present position. Another evidence for damages also occurs at ChumSungDae astronomical observatory. One possible cause for these destructions and damages is paleoseismicity in this area.

  17. Exotic topological insulator states and topological phase transitions in Sb2Se3-Bi2Se3 heterostructures

    KAUST Repository

    Zhang, Qianfan; Zhang, Zhiyong; Zhu, Zhiyong; Schwingenschlö gl, Udo; Cui, Yi

    2012-01-01

    in controlling the electronic properties of semiconductor devices, are interesting for topological insulators. Here, we studied the spatial distribution of the topological state in Sb 2Se 3-Bi 2Se 3 heterostructures by first-principle simulation and discovered

  18. Effect of dietary sodium selenite, Se-enriched yeast and Se-enriched Chlorella on egg Se concentration, physical parameters of eggs and laying hen production

    Czech Academy of Sciences Publication Activity Database

    Skřivan, M.; Šimáně, J.; Dlouhá, G.; Doucha, Jiří

    2006-01-01

    Roč. 51, č. 4 (2006), s. 163-167 ISSN 1212-1819 Institutional research plan: CEZ:AV0Z50200510 Keywords : sodium selenite * se-yeast * se-chlorella Subject RIV: EE - Microbiology, Virology Impact factor: 0.421, year: 2006

  19. PbSe Quantum Well VECSEL on Si

    Science.gov (United States)

    Fill, M.; Khiar, A.; Rahim, M.; Felder, F.; Zogg, H.

    2011-12-01

    Vertical external cavity surface emitting lasers in the wavelength region from 3-5 μm are presented. They are based on PbSe quantum wells grown on Si substrates. As host material Pb1-xEuxSe and Pb1-xSrxSe are used. With Pb1-xSrxSe as host material maximum operation temperatures of 325 K are achieved, while with Pb1-xEuxSe an operation temperature of 245 K could not be overcome. This may be explained by a band alignment transition from type I to type II with increasing temperature.

  20. Quiet areas

    DEFF Research Database (Denmark)

    Petersen, Rikke Munck

    2016-01-01

    This paper argues that drone filming can substantiate our understanding of multisensorial experiences of quiet areas and urban landscapes. Contrary to the distanced gaze often associated with the drone, this paper discusses drone filming as an intimate performativity apparatus that can affect...... perception as a result of its interrelationships between motion, gaze, and sound. This paper uses four films, one of which is a drone flyover, to launch a discussion concerning a smooth and alluring gaze, a sliding gaze that penetrates landscapes, and site appearance. Films hold the capacity to project both...... and transcendence can facilitate a deeper understanding of intimate sensations, substantiating their role in the future design and planning of urban landscapes. Hence, it addresses the ethics of an intimacy perspective (of drone filming) in the qualification of quiet areas....

  1. Lateral structure of (TiSe2)n(NbSe2)m superlattices

    International Nuclear Information System (INIS)

    Noh, M.; Shin, H.; Jeong, K.; Spear, J.; Johnson, D.C.; Kevan, S.D.; Warwick, T.

    1997-01-01

    The structures of a series of (TiSe 2 ) n (NbSe 2 ) m superlattices grown through controlled crystallization of designed multilayer reactants have been studied. X-ray diffraction of the data of the superlattices after crystallization show considerable preferred orientation, with the basal plane of the dichalcogenide structure parallel to the substrate to within 0.1 degree. Lattice refinement using the observed (00scr(l)) diffraction maxima yields lattice parameters along the c axis that are consistent with those expected based on the target superlattices and lattice parameters of the binary constituents. These (00scr(l)) diffraction data, however, contain no information about the crystalline structure in the ab plane of the superlattice associated with the preferred c-axis orientation. Off-specular x-ray diffraction (XRD), scanning electron microscopy, and scanning transmission x-ray microscopy (STXM) were used to explore the structure and homogeneity of the superlattices in the ab plane. XRD results rule out preferred long-range orientational order of the ab plane. Between grains, both the backscattered electron images and STXM images show grain domain structure in the ab plane with a characteristic grain domain size of approximately 50 μm. X-ray absorption microscopy in the STXM mode obtained at the Ti L 2,3 edge shows that the titanium in the superlattices is present as both octahedral Ti consistent with the TiSe 2 structure and metallic Ti. A comparison of the data obtained from these techniques highlights chemical information, which can be deduced on a submicrometer range from the space resolved spectra obtained using STXM. copyright 1997 American Institute of Physics

  2. Protected areas in mountains

    Directory of Open Access Journals (Sweden)

    Hamilton, L. S.

    2006-12-01

    Full Text Available

    The importance of a global Protected Areas Network in sustaining appropriate mountain development is presented in this paper. Present status of the world’s “official” Protected Areas in the UN List, and the proportion that are in mountain areas, and including international designations (World Heritage and Biosphere Reserves. Current and future challenges in the management of these special areas are also commented.



    El autor destaca la importancia de una Red Mundial de Espacios Protegidos para el desarrollo sostenible de las montañas. Comenta luego el estatus actual de las Áreas Protegidas “oficiales” del Mundo en la Lista de las Naciones Unidas y qué proporción de ellas forma parte de las montañas, sin olvidar las figuras internacionales de protección como Patrimonio de la Humanidad y Reservas de Biosfera. Para terminar, se discuten los problemas de gestión actuales y futuros de estas áreas tan especiales

  3. Superconductivity in the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n}

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Corinna; Chiatti, Olivio; Fischer, Saskia F. [Novel Materials Group, Humboldt-Universitaet Berlin (Germany); Alemayehu, Matti B.; Falmbigl, Matthias; Johnson, David C. [Department of Chemistry, University of Oregon, Eugene, OR (United States)

    2016-07-01

    The ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} are artificially layered materials consisting of n NbSe{sub 2} single-layers stacked alternately with atomic double layers of PbSe. NbSe{sub 2} is a transition metal dichalcogenide with interesting electrical properties such as superconductivity and charge density waves. The influence of turbostratic disorder, a random rotation between the NbSe{sub 2} and PbSe layers, on the superconducting transition temperature has been unknown so far. We investigate the structural and temperature-dependent electrical properties of the ferecrystals (PbSe){sub 1.14}(NbSe{sub 2}){sub n} by means of scanning transmission electron microscopy, X-ray diffraction, in-plane resistivity and Hall measurements and compare them to those of analogous non-disordered misfit layer compound (MLC) polymorphs. We observe a superconducting transition in the resistivity of the ferecrystals. The transition temperatures are reduced by up to 55 % with respect to the analogous MLC polymorphs. This indicates that turbostratic disorder substantially weakens the electron-phonon coupling in (PbSe){sub 1.14}(NbSe{sub 2}){sub n}. We discuss the results of the structural and electrical properties of the ferecrystals with respect to their MLC analogues and also with respect to ultra-thin NbSe{sub 2} layers.

  4. Direct solution-phase synthesis of Se submicrotubes using Se powder as selenium source

    International Nuclear Information System (INIS)

    Yan Shancheng; Wang Haitao; Zhang Yuping; Li Shuchun; Xiao Zhongdang

    2009-01-01

    The selenium submicrotubes were directly prepared using Se powder as selenium source by microwave-assisted method. Field-emission scan electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were adopted to characterize the as-prepared products. The results of high-resolution transmission electron microscopy (HRTEM) and XRD pattern proved that the selenium submicrotubes were single crystalline in nature and [0 0 1] oriented. A possible growth mechanism of the selenium submicrotubes was proposed. The effects of the experimental conditions, such as alkaline concentration and solvent properties, on the morphology and dimension of the products have also been discussed

  5. Complexing in (NH4)2SeO4-UO2SeO4 H2O system

    International Nuclear Information System (INIS)

    Serezhkina, L.B.

    1994-01-01

    Isotherm of solubility in the (NH 4 ) 2 SeO 4 -UO 2 SeO 4 -H 2 O system has been constructed at 25 deg C. (NH 4 ) 2 (UO 2 ) 2 (SeO 4 ) 3 x6H 2 O formation is established for the first time and certain its physicochemical properties are determined. Regularities of complexing in the R 2 Se) 4 -UO 2 SeO 4 -H 2 O systems, where R-univalent cation are under discussion. 6 refs.; 3 tabs

  6. SeP, ApoER2 and megalin as necessary factors to maintain Se homeostasis in mammals.

    Science.gov (United States)

    Krol, Magdalena Beata; Gromadzinska, Jolanta; Wasowicz, Wojciech

    2012-10-01

    Selenoprotein P (SeP) is an extracellular protein containing ten selenium atoms in the form of selenocysteine, secreted mainly from the liver. About 60% of the whole plasma selenium level is present in SeP, which makes it a useful biomarker of selenium nutritional status. The main functions of SeP are transport and storage of selenium in plasma. It is especially an important protein for the brain, testes and kidneys where the supplementation of the proper amount of Se ensures the synthesis of selenoenzymes with antioxidant properties.Recently, it has been found that SeP uptake in kidneys, testes and brain depends on the apolipoprotein receptor 2 (ApoER2) and lipoprotein megalin receptor (Lrp2). Megalin receptor represents a physiological SeP receptor in kidneys, mediating the re-uptake of secreted SeP from the primary urine. The absence of a functional megalin receptor causes a significant reduction of plasma selenium and the SeP levels as a result of Se excretion. ApoER2 is a SeP receptor in the brain and testes which uptakes Se from the extracellular fluid. Deletion of ApoER2 in mice leads to a lowered selenium level in the brain and testes, neurological dysfunction, production of abnormal spermatozoa, infertility and even death when the subjects are fed a low-selenium diet. Copyright © 2012 Elsevier GmbH. All rights reserved.

  7. Simultaneous tracing of 76Se-selenite and 77Se-selenomethionine by absolute labeling and speciation

    International Nuclear Information System (INIS)

    Suzuki, Kazuo T.; Somekawa, Layla; Kurasaki, Kazuki; Suzuki, Noriyuki

    2006-01-01

    Nutritional selenocompounds are transformed into the assumed common intermediate selenide, which is utilized for the synthesis of selenoenzymes or transformed into methylated metabolites for excretion. Hence, selenocompound metabolites can be traced only with labeled selenium. Here we applied a new tracer method for the metallomics of biometals using simultaneous speciation of each metallome labeled with different homo-elemental isotopes to metabolism and availability of selenium. Rats were depleted of endogenous natural abundance selenium by feeding a single selenium stable isotope ( 82 Se-selenite) and then administered 76 Se-selenite and 77 Se-selenomethionine ( 77 Se-SeMet)simultaneously. Biological samples were subjected to quantification and speciation analysis by HPLC-ICPMS. Metabolites of the labeled 76 Se and 77 Se and interaction with endogenous selenium were traced and examined without interference from the corresponding endogenous natural abundance isotopes. Differences in the distribution and metabolism among organs and between the two nutritional selenocompounds were compared under exactly identical biological and analytical conditions: (1) selenite was distributed more efficiently than SeMet in organs and body fluids except the pancreas. (2) SeMet was taken up by organs in its intact form. (3) Selenium of SeMet origin was distributed selectively in the pancreas and mostly bound to a protein together with intact SeMet. (4) Selenosugars A and B but not trimethylselenonium (TMSe) were detected in the liver. (5) Selenosugar B and TMSe were detected in the kidneys

  8. Synthesis of CdSe Quantum Dots Using Fusarium oxysporum

    Directory of Open Access Journals (Sweden)

    Takaaki Yamaguchi

    2016-10-01

    Full Text Available CdSe quantum dots are often used in industry as fluorescent materials. In this study, CdSe quantum dots were synthesized using Fusarium oxysporum. The cadmium and selenium concentration, pH, and temperature for the culture of F. oxysporum (Fusarium oxysporum were optimized for the synthesis, and the CdSe quantum dots obtained from the mycelial cells of F. oxysporum were observed by transmission electron microscopy. Ultra-thin sections of F. oxysporum showed that the CdSe quantum dots were precipitated in the intracellular space, indicating that cadmium and selenium ions were incorporated into the cell and that the quantum dots were synthesized with intracellular metabolites. To reveal differences in F. oxysporum metabolism, cell extracts of F. oxysporum, before and after CdSe synthesis, were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. The results suggested that the amount of superoxide dismutase (SOD decreased after CdSe synthesis. Fluorescence microscopy revealed that cytoplasmic superoxide increased significantly after CdSe synthesis. The accumulation of superoxide may increase the expression of various metabolites that play a role in reducing Se4+ to Se2− and inhibit the aggregation of CdSe to make nanoparticles.

  9. Synthesis of dextran/Se nanocomposites for nanomedicine application

    International Nuclear Information System (INIS)

    Shen Yuhua; Wang Xiufang; Xie Anjian; Huang Lachun; Zhu Jinmiao; Chen Long

    2008-01-01

    In this study, spherical Se nanoparticles were prepared by the reduction of aqueous selenious acid with ice bath through a simple, conventional, and one-step method without the aid of any surfactant, or template. The nanoparticles were characterized by transmission electron microscopy (TEM), photon correlation spectroscopy (PCS), X-ray powder diffraction (XRD), Ultraviolet-visible spectroscopy (UV-vis), Zeta potential, respectively. The results show the Se nanoparticles have good particle dispersion with the average diameters of 36 nm and are amorphous (α-Se). Tablets A and B containing dextran and Se nanoparticles were synthesized with different preparation methods. Se nanoparticles studded equably in the interior and the surface of the tablets, and there are strong interactions between Se and dextran. The release of Se from tablets is investigated in the simulated gastric and intestinal conditions. It is found that the pH environment and different synthetical methods have significant influence on the release rate of Se. The release mechanism of Se nanoparticles is also discussed. The nanocomposites can be applied in controlled releasing of Se nanomedicine

  10. Summary of Synoptic Meteorological Observations. Siberian Coastal Marine Areas. Volume 3. Area 15 - Okhotsk Sea NE, Area 16 - West Coast Kamchatka, Area 17 - Tatar Strait N, Area 18 - Tatar Strait S, Area 19 - Okhotsk Sea SW, Area 20 - Sakhalin Island SE, Area 21 - Okhotsk Sea SE

    Science.gov (United States)

    1975-10-01

    8217 " ■., . "■ ’■<*. PEKIODI IPRIDARY) 1939-197* (OVER-ALL) 1907-197* 1UCUST TtlU 17 ADEl 0016 HtST COAST KtMCHAUA 9A.AN 15J.JE rCT ntQ 0f AIR...8217—■ ■- ^"’"’""ÜIBMÜMIÜlffifattllll i^iuiimb&m<miiM& *J W \\j- \\j PEKIQOI (DVER-4LLI 1961-1974 OCTUBE« TABLE U (CONTI «Kt» 0016 HtST CUA$T ««^CHJTK» S4.1N

  11. Timely resolved measurements on CdSe nanoparticles; Zeitaufgeloeste Messungen an CdSe Nanopartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Holt, B.E. von

    2006-06-06

    By means of infrared spectroscopy the influence of the organic cover on structure and dynamics of CdSe nanoparticles was studied. First a procedure was developed, which allows to get from the static infrared spectrum informations on the quality of the organic cover and the binding behaviour of the ligands. On qualitatively high-grade and well characterized samples thereafter the dynamics of the lowest-energy electron level 1S{sub e} was time-resolvedly meausred in thew visible range. As reference served CdSe TOPO, which was supplemented by samples with the ligands octanthiole, octanic acid, octylamine, naphthoquinone, benzoquinone, and pyridine. The studied nanoparticles had a diameter of 4.86 nm. By means of the excitation-scanning or pump=probe procedure first measurements in the picosecond range were performed. The excitation wavelengths were thereby spectrally confined and so chosen that selectively the transitions 1S{sub 3/2}-1S-e and 1P{sub 3/2}-1P{sub e} but not the intermediately lyingt transition 2S{sub 3/2}-1S{sub e} were excited. The excitation energies were kept so low that the excitation of several excitons in one crystal could be avoided. The scanning wavelength in the infrared corresponded to the energy difference between the electron levels 1S{sub e} and 1P{sub e}. The transients in the picosecond range are marked by a steep increasement of the signal, on which a multi-exponential decay follows. The increasement, which reproduces the popiulation of the excited state, isa inependent on the choice of the ligands. The influence of the organic cover is first visible in the different decay times of the excited electron levels. the decay of the measurement signal of CdSe TOPO can be approximatively described by three time constants: a decay constant in the early picosecond region, a time constant around hundert picoseconds, and a time constant of some nanoseconds. At increasing scanning wavelength the decay constants become longer. By directed excitation

  12. Negative ion photoelectron spectroscopy of SeO-

    International Nuclear Information System (INIS)

    Coe, J.V.; Snodgrass, J.T.; Freidhoff, C.B.; McHugh, K.M.; Bowen, K.H.

    1985-01-01

    Negative ion photoelectron spectroscopy (NIPES) involves a kinetic energy analysis of electrons which are photodetached when a mass selected beam of negative ions is crossed with a fixed frequency laser beam. The photodetachment spectra of SeO - displays transitions from the X 2 PI state of SeO - to both the X 3 Σ - and a 1 Δ states of SeO. The singlet-triplet splitting of SeO is readily observable since selection rules regarding spin do not apply in the bound to free state process of photodetachment. The electron affinity of SeO and the negative ion potential parameters of SeO - have been determined

  13. PySE: Software for extracting sources from radio images

    Science.gov (United States)

    Carbone, D.; Garsden, H.; Spreeuw, H.; Swinbank, J. D.; van der Horst, A. J.; Rowlinson, A.; Broderick, J. W.; Rol, E.; Law, C.; Molenaar, G.; Wijers, R. A. M. J.

    2018-04-01

    PySE is a Python software package for finding and measuring sources in radio telescope images. The software was designed to detect sources in the LOFAR telescope images, but can be used with images from other radio telescopes as well. We introduce the LOFAR Telescope, the context within which PySE was developed, the design of PySE, and describe how it is used. Detailed experiments on the validation and testing of PySE are then presented, along with results of performance testing. We discuss some of the current issues with the algorithms implemented in PySE and their interaction with LOFAR images, concluding with the current status of PySE and its future development.

  14. Atomic Defects and Doping of Monolayer NbSe2.

    Science.gov (United States)

    Nguyen, Lan; Komsa, Hannu-Pekka; Khestanova, Ekaterina; Kashtiban, Reza J; Peters, Jonathan J P; Lawlor, Sean; Sanchez, Ana M; Sloan, Jeremy; Gorbachev, Roman V; Grigorieva, Irina V; Krasheninnikov, Arkady V; Haigh, Sarah J

    2017-03-28

    We have investigated the structure of atomic defects within monolayer NbSe 2 encapsulated in graphene by combining atomic resolution transmission electron microscope imaging, density functional theory (DFT) calculations, and strain mapping using geometric phase analysis. We demonstrate the presence of stable Nb and Se monovacancies in monolayer material and reveal that Se monovacancies are the most frequently observed defects, consistent with DFT calculations of their formation energy. We reveal that adventitious impurities of C, N, and O can substitute into the NbSe 2 lattice stabilizing Se divacancies. We further observe evidence of Pt substitution into both Se and Nb vacancy sites. This knowledge of the character and relative frequency of different atomic defects provides the potential to better understand and control the unusual electronic and magnetic properties of this exciting two-dimensional material.

  15. Symmetry and optical anisotropy in CdSe/ZnSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kiessling, Tobias

    2009-10-29

    The material system of choice for the investigations performed in the frame of this Thesis were self-assembled CdSe/ZnSe QDs. The reason for this choice is twofold. First, CdSe/ZnSe QDs can be grown with excellent optical quality, which is a prerequiste for optical studies. Second, due to the polar nature of II-VI compound semiconductors, optical anisotropies induced by various asymmetries are more pronounced than in their IIIV or element IV counterparts. Unlike in the III-V materials, where the self-organization of QDs is well described by the Stranski-Krastanow growth mode, the peculiarities of the QD formation are not entirely clear in II-VI alloys. For the purposes of the current work QDs emerging from two variants of Molecular Beam Epitaxy (MBE) growth were studied. In order to establish a clear connection between the optically observed anisotropies and the growth induced asymmetries in the QDs we start out by summarizing all available structural and morphological studies that were performed on the resultant QDs, including x-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy and resonant Raman scattering. Extensive investigations by Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectroscopy hence detail the resultant electronic structure of excitons confined to the above QDs as well as their energy relaxation across the latter. We find that for these small-sized strongly confining QDs k-vector conservation is entirely relaxed, which enables interaction of the excitons with a continuum of phonons and explains fast and efficient exciton capture by the QDs, even for excitation conditions far above the ground state. We demonstrate how this provides an alternative fast relaxation channel to Auger-like electron-hole scattering, that may also explain fast hole relaxation and adds to the understanding of the absence of a phonon bottleneck in the energy relaxation in these type of QDs. With the above analysis as a

  16. Symmetry and optical anisotropy in CdSe/ZnSe quantum dots

    International Nuclear Information System (INIS)

    Kiessling, Tobias

    2009-01-01

    The material system of choice for the investigations performed in the frame of this Thesis were self-assembled CdSe/ZnSe QDs. The reason for this choice is twofold. First, CdSe/ZnSe QDs can be grown with excellent optical quality, which is a prerequiste for optical studies. Second, due to the polar nature of II-VI compound semiconductors, optical anisotropies induced by various asymmetries are more pronounced than in their IIIV or element IV counterparts. Unlike in the III-V materials, where the self-organization of QDs is well described by the Stranski-Krastanow growth mode, the peculiarities of the QD formation are not entirely clear in II-VI alloys. For the purposes of the current work QDs emerging from two variants of Molecular Beam Epitaxy (MBE) growth were studied. In order to establish a clear connection between the optically observed anisotropies and the growth induced asymmetries in the QDs we start out by summarizing all available structural and morphological studies that were performed on the resultant QDs, including x-ray diffraction, atomic force microscopy, high resolution transmission electron microscopy and resonant Raman scattering. Extensive investigations by Photoluminescence (PL) and Photoluminescence Excitation (PLE) spectroscopy hence detail the resultant electronic structure of excitons confined to the above QDs as well as their energy relaxation across the latter. We find that for these small-sized strongly confining QDs k-vector conservation is entirely relaxed, which enables interaction of the excitons with a continuum of phonons and explains fast and efficient exciton capture by the QDs, even for excitation conditions far above the ground state. We demonstrate how this provides an alternative fast relaxation channel to Auger-like electron-hole scattering, that may also explain fast hole relaxation and adds to the understanding of the absence of a phonon bottleneck in the energy relaxation in these type of QDs. With the above analysis as a

  17. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-05-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  18. Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

    Science.gov (United States)

    Zhang, Min; Wei, Zhan-Tao

    2018-03-01

    Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

  19. SeRLoc: Robust Localization for Wireless Sensor Networks

    National Research Council Canada - National Science Library

    Lazos, Loukas; Poovendran, Radha

    2005-01-01

    .... We show that SeRLoc is robust against known attacks on WSNs such as the wormhole attack, the Sybil attack, and compromise of network entities and analytically compute the probability of success for each attack. We also compare the performance of SeRLoc with state-of-the-art range-independent localization schemes and show that SeRLoc has better performance.

  20. Atomic defects and doping of monolayer NbSe2

    OpenAIRE

    Nguyen, Lan; Komsa, Hannu-Pekka; Khestanova, Ekaterina; Kashtiban, Reza J; Peters, Jonathan J.P.; Lawlor, Sean; Sanchez, Ana M.; Sloan, Jeremy; Gorbachev, Roman; Grigorieva, Irina; Krasheninnikov, Arkady V.; Haigh, Sarah

    2017-01-01

    We have investigated the structure of atomic defects within monolayer NbSe2 encapsulated in graphene by combining atomic resolution transmission electron microscope imaging, density functional theory (DFT) calculations, and strain mapping using geometric phase analysis. We demonstrate the presence of stable Nb and Se monovacancies in monolayer material and reveal that Se monovacancies are the most frequently observed defects, consistent with DFT calculations of their formation energy. We reve...

  1. Enhanced thermoelectric properties of N-type polycrystalline In4Se3-x compounds via thermally induced Se deficiency

    Science.gov (United States)

    Zhao, Ran; Shu, Yu-Tian; Guo, Fu

    2014-03-01

    In4Se3-x compound is considered as a potential thermoelectric material due to its comparably low thermal conductivity among all existing ones. While most studies investigated In4Se3-x thermoelectric properties by controlling selennium or other dopants concentrations, in the current study, it was found that even for a fixed initial In/Se ratio, the resulting In/Se ratio varied significantly with different thermal processing histories (i.e., melting and annealing), which also resulted in varied thermoelectric properties as well as fracture surface morphologies of In4Se3-x polycrystalline specimens. Single phase polycrystalline In4Se3-x compounds were synthesized by combining a sequence of melting, annealing, pulverizing, and spark plasma sintering. The extension of previous thermal history was observed to significantly improve the electrical conductivity (about 121%) and figure of merit (about 53%) of In4Se3-x polycrystalline compounds. The extended thermal history resulted in the increase of Se deficiency (x) from 0.39 to 0.53. This thermally induced Se deficiency was observed to associate with increasing carrier mobility but decreasing concentration, which differs from the general trend observed for the initially adjusted Se deficiency at room temperature. Unusually large dispersed grains with nanosize layers were observed in specimens with the longest thermal history. The mechanism(s) by which previous thermal processing enhances carrier mobility and affect microstructural evolution are briefly discussed.

  2. Structural and optical properties of nanocrystalline CdSe and Al:CdSe thin films for photoelectrochemical application

    Energy Technology Data Exchange (ETDEWEB)

    Gawali, Sanjay A. [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004 (India); Bhosale, C.H., E-mail: bhosale_ch@yahoo.com [Electrochemical Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004 (India)

    2011-10-03

    Highlights: {yields} The CdSe and Al:CdSe thin films have been successfully deposited by SPT. {yields} Hexagonal cubic structured CdSe and Al: CdSe thin films are observed. {yields} Large number of fine grains, Uniform and compact growth morphology. {yields} Hydrophilic surface nature. {yields} Al:CdSe have better PEC performance than CdSe. - Abstract: Nanocrystalline CdSe and Al:CdSe semiconductor thin films have been successfully synthesized onto amorphous and FTO glass substrates by spray pyrolysis technique. Aqueous solutions containing precursors of Cd and Se have been used to obtain good quality films. The optimized films have been characterized for their structural, morphological, wettability and optical properties. X-ray diffraction (XRD) studies show that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy (SEM) studies show that the film surface is smooth, uniform and compact in nature. Water wettability study reveals that the films are hydrophilic behavior. The formation of CdSe and Al:CdSe thin film were confirmed with the help of FTIR spectroscopy. UV-vis spectrophotometric measurement showed a direct allowed band gap lying in the range 1.673-1.87 eV. Output characteristics were studied by using cell configuration n- CdSe/Al:CdSe |1 M (NaOH + Na{sub 2} + S)|C. An efficient solar cell having a power conversion efficiency of 0.38% at illumination 25 mW cm{sup -2} was fabricated.

  3. 13.7%-efficient Zn(Se,OH){sub x}/Cu(In,Ga)(S,Se){sub 2} thin-film solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Ennaoui, A. [Hahn-Meitner-Institut, Bereich Physikalische Chemie, Berlin (Germany); Blieske, U.; Lux-Steiner, M.Ch. [Hahn-Meitner-Institut, Bereich Festkoerperphysik, Berlin (Germany)

    1998-12-01

    Cu(In,Ga)Se{sub 2} (CIGS) and related semiconducting compounds have demonstrated their high potential for high-efficiency thin-film solar cells. The highest efficiency for CIGS based thin-film solar cells has been achieved with CdS buffer layers prepared by a solution growth method known as chemical based deposition (CBD). With the aim of developing Cd-free chalcopyrite-based thin-film solar cells, Zn(Se,OH){sub x} buffer layers were deposited by CBD on polycrystalline Cu(In,Ga)(S,Se){sub 2} (CIGSS). A total-area conversion efficiency of 13.7% was certified by the Fraunhofer Institute for Solar Energy Systems. The CIGSS absorber was fabricated by Siemens Solar Industries (California). For device optimisation, the thickness and good surface coverage were controlled by XPS-UPS photoemission spectroscopy. A Zn(Se,OH){sub x} thickness below 7 nm has been found to be optimum for achieving a homogeneous and compact buffer film on CIGSS, with open-circuit photovoltage V{sub oc} = 535 mV, fill factor FF = 70.76% and a high short-circuit photocurrent density J{sub sc} 36.1 mA cm{sup -2}. (Author)

  4. Cultivation and characterization of GaInSe2 crystals

    International Nuclear Information System (INIS)

    Panakhov, T.M.; Kafarova, D.M.

    2013-01-01

    This work is the first systematic study devoted to the growth of GaInSe 2 crystals and their characterization by experimental methods such as X-ray diffraction, electron microscopy transmission with high resolution, sample electron diffraction. By the method of photoelectron roentgen spectroscopy it was studied the chemical structure of the GaInSe 2 crystals and the microprobe analysis indicated that the individual crystals have an excess of gallium. GaInSe 2 crystals were grown by the Bridgman method. Samples were prepared as single crystals by the Bridgman method. Studies showed that the GaInSe 2 crystals are hexagonal ones

  5. Epitaxial CdSe-Au nanocrystal heterostructures by thermal annealing.

    Science.gov (United States)

    Figuerola, Albert; van Huis, Marijn; Zanella, Marco; Genovese, Alessandro; Marras, Sergio; Falqui, Andrea; Zandbergen, Henny W; Cingolani, Roberto; Manna, Liberato

    2010-08-11

    The thermal evolution of a collection of heterogeneous CdSe-Au nanosystems (Au-decorated CdSe nanorods, networks, vertical assemblies) prepared by wet-chemical approaches was monitored in situ in the transmission electron microscope. In contrast to interfaces that are formed during kinetically controlled wet chemical synthesis, heating under vacuum conditions results in distinct and well-defined CdSe/Au interfaces, located at the CdSe polar surfaces. The high quality of these interfaces should make the heterostructures more suitable for use in nanoscale electronic devices.

  6. ¿Como se hace publicidad por internet?

    Directory of Open Access Journals (Sweden)

    Franz Del Pozo

    2015-01-01

    Full Text Available Internet es el medio de comunicación y venta con el mayor potencial de crecimiento y efectividad al más bajo precio. Para vender se usan tarjetas de crédito, depósitos bancarios, franqueo, comercio electrónico. Explica qué y cómo se hace publicidad por Internet. La Red se usa para difundir y para vender y hay la posibilidad de hacer algo diferente a más de llegar directamente al público objetivo se interactúa con él.

  7. Determination of K shell fluorescence cross-section and Kβ/Kα intensity ratios for Fe, Se, Te, FeSe, FeTe and TeSe

    International Nuclear Information System (INIS)

    Saydam, M.; Aksoy, C.; Cengiz, E.; Alaşalvar, C.; Tıraşoğlu, E.; Apaydın, G.

    2012-01-01

    The fluorescence cross-sections (σ Ki ) and the intensity ratios K β /K α for pure Fe, Se, Te elements and FeSe, FeTe, TeSe complexes have been investigated. The samples were excited by 59.5 keV γ-rays from 241 Am annular radioactive source and emitted X-rays. They were counted by an Ultra-LEGe detector with resolution of 150 eV at 5.9 keV. For pure elements results have been compared with the theoretical calculated values. According to our results band length and mutual interaction of atoms affected the results. We claimed that these effects would help researchers who study on superconductors, especially determining which compound can be show the superconductor properties. - Highlights: ► TeSe, FeSe and FeTe complexes have affected each other in terms of charge transfer. ► Fe excitement and enhancement have been made by Se and Te. ► Attractive interactions between electrons can help to becoming superconductivity.

  8. Hot exciton relaxation in multiple layers CdSe/ZnSe self-assembled quantum dots separated by thick ZnSe barriers

    International Nuclear Information System (INIS)

    Eremenko, M; Budkin, G; Reznitsky, A

    2015-01-01

    We have studied PL and PLE spectra of two samples (A and B) of MBE grown CdSe/ZnSe asymmetric double quantum wells with different amount of deposited CdSe layers separated by 14 nm ZnSe barrier. It has been found that PLE spectra of the states forming short wavelength side of the PL spectra of both deep and shallow QWs of the sample A as well as that of deep QW of the sample B demonstrate oscillating structure in the spectral ranges corresponding to exciton states of self-assembled quantum dots only. Meanwhile PLE spectra of the short wavelength states of shallow QW the sample B revealed pronounced oscillating structure with energy period of ZnSe LO phonon under excitation with photons in a wide energy range both in the regions of quantum-dot states and in that of free states in the ZnSe barrier. In these spectra creating of excitons with kinetic energies more than 0.3 eV was observed which considerably exceed the exciton binding energy as well as LO phonon energy (both appr. 0.03 eV). It has been concluded that oscillating structure of the PLE spectra arises due to cascade relaxation of hot excitons. We discuss the model which explains these experimental findings. (paper)

  9. Hot exciton relaxation in multiple layers CdSe/ZnSe self-assembled quantum dots separated by thick ZnSe barriers

    Science.gov (United States)

    Eremenko, M.; Budkin, G.; Reznitsky, A.

    2015-11-01

    We have studied PL and PLE spectra of two samples (A and B) of MBE grown CdSe/ZnSe asymmetric double quantum wells with different amount of deposited CdSe layers separated by 14 nm ZnSe barrier. It has been found that PLE spectra of the states forming short wavelength side of the PL spectra of both deep and shallow QWs of the sample A as well as that of deep QW of the sample B demonstrate oscillating structure in the spectral ranges corresponding to exciton states of self-assembled quantum dots only. Meanwhile PLE spectra of the short wavelength states of shallow QW the sample B revealed pronounced oscillating structure with energy period of ZnSe LO phonon under excitation with photons in a wide energy range both in the regions of quantum-dot states and in that of free states in the ZnSe barrier. In these spectra creating of excitons with kinetic energies more than 0.3 eV was observed which considerably exceed the exciton binding energy as well as LO phonon energy (both appr. 0.03 eV). It has been concluded that oscillating structure of the PLE spectra arises due to cascade relaxation of hot excitons. We discuss the model which explains these experimental findings.

  10. Rainfall erosivity in the Upper Llobregat Basin, SE Pyrenees

    Directory of Open Access Journals (Sweden)

    Gallart, F.

    2010-12-01

    Full Text Available The aim of this study was to determine the spatial distribution of rainfall erosivity in a 504 km2 river basin in Eastern Pyrenees and assess its uncertainties. The study area is topographically complex and is dominated by Mediterranean climate with intense rains during summer. Available rainfall dataset includes 14 years spanning from 1991 to 2004 at daily resolution from seven weather stations and sub-hourly from one station. Daily R values were calculated from sub-hourly data, and then by using the relationship between daily R values and precipitation, the R values for weather stations having only daily rainfall resolution were calculated. The error propagation by using such upscaling approach was analyzed. The studied sources of uncertainty of R factor at annual scale were: the use of the relationship between daily R values and precipitation, the temporal averaging of R values and spatial variation. Results have shown that at annual scale the temporal averaging was the largest contributor of uncertainty (70%; however this contribution decreased significantly (14% when R was estimated for the long term.

    El objetivo de este estudio fue determinar la distribución espacial de la erosividad de precipitación en una cuenca de 504 km2 en el Este de los Pirineos y evaluar sus incertidumbres. El área de estudio presenta una topografía compleja y está dominada por un clima Mediterráneo con lluvias intensas durante el verano. Los datos de precipitación utilizados abarcan 14 años, desde 1991 hasta 2004, a una resolución diaria en siete estaciones meteorológicas y minutal en una estación. Los valores diarios de R se calcularon a partir de datos con resolución minutal, y luego se estableció una relación entre valores diarios de R y precipitación, con el fin de calcular los valores de R para las estaciones meteorológicas que sólo presentan resolución diaria. Las fuentes de incertidumbre considerados para el

  11. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    International Nuclear Information System (INIS)

    Risberg, Jan

    2002-12-01

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  12. Holocene sediment accumulation in the Aespoe area. A study of a sediment core

    Energy Technology Data Exchange (ETDEWEB)

    Risberg, Jan [Stockholm Univ. (Sweden). Dept. of Quaternary Research

    2002-12-01

    A sediment core was collected in 1993 in the archipelago above the tunnel between the Aespoe Island and Simpevarp nuclear power plant. The sediment sequence consists of four types of accumulations: brownish clay, bluish clay, sand mixed with gravel and gyttja. The sequence was studied according to its content of siliceous microfossils (mainly diatoms), mineral magnetic characteristics, clay mineralogy and it was dated by the AMS technique on bulk sediment samples. According to the diatom content, both types of clay were probably deposited during the brackish water Yoldia Sea stage. The clay is relatively uniform, except an abrupt increase in the mineral magnetic parameters HIRM and S-ratio at around 810 cm depth, which probably is the result from a change in the material source. The clay mineralogy, with enhanced chlorite values, indicates a relatively uniform material. A major change occurs at the transition from the bluish to brownish clay, where all magnetic concentrations drop dramatically as the result from a major shift in material source and/or sedimentation environment. The thin layer of sand and gravel is indicative of a major hiatus in the stratigraphy. Mineral magnetic concentrations increase slightly as the result from mixing with single domain ground surface generated particles. Based on a Yoldia Sea age for the underlying clay and deposition in the Litorina Sea 3000 years BP for the superimposed gyttja, it is suggested that the length of the hiatus is about 7000 years. It is not until the studied site became protected enough by rising land areas, that organic rich gyttja started to accumulate.It is likely that this scenario was established when sea level was situated at around 10 m above present day. Since then it seems, as determined from the mineral magnetic graphs, that the sedimentary conditions have been relatively uniform. More pronounced fluctuations in mineral magnetic concentrations (especially ARM/SIRM ratios)in the upper 2 m of the core

  13. Stable and metastable equilibria in PbSe + SnI2=SnSe + PbI2

    International Nuclear Information System (INIS)

    Odin, I.N.; Grin'ko, V.V.; Kozlovskij, V.F.; Demidova, E.D.

    2003-01-01

    T-x-y phase diagrams of the PbSe + SnI 2 =SnSe + PbI 2 mutual system (stable states) are plotted for the first time. It is shown that melt, solid solutions on the base of components of the mutual system and phase on the base of Sn 2 SeI 4 take part in phase equilibria. Transformations in the PbSe + SnI 2 =SnSe + PbI 2 mutual system leading to crystallization of metastable polytype modifications of lead iodides and metastable ternary compound forming in PbSe-PbI 2 system are investigated for the first time [ru

  14. Electronic structure and superconductivity of FeSe-related superconductors.

    Science.gov (United States)

    Liu, Xu; Zhao, Lin; He, Shaolong; He, Junfeng; Liu, Defa; Mou, Daixiang; Shen, Bing; Hu, Yong; Huang, Jianwei; Zhou, X J

    2015-05-13

    FeSe superconductors and their related systems have attracted much attention in the study of iron-based superconductors owing to their simple crystal structure and peculiar electronic and physical properties. The bulk FeSe superconductor has a superconducting transition temperature (Tc) of ~8 K and it can be dramatically enhanced to 37 K at high pressure. On the other hand, its cousin system, FeTe, possesses a unique antiferromagnetic ground state but is non-superconducting. Substitution of Se with Te in the FeSe superconductor results in an enhancement of Tc up to 14.5 K and superconductivity can persist over a large composition range in the Fe(Se,Te) system. Intercalation of the FeSe superconductor leads to the discovery of the AxFe2-ySe2 (A = K, Cs and Tl) system that exhibits a Tc higher than 30 K and a unique electronic structure of the superconducting phase. A recent report of possible high temperature superconductivity in single-layer FeSe/SrTiO3 films with a Tc above 65 K has generated much excitement in the community. This pioneering work opens a door for interface superconductivity to explore for high Tc superconductors. The distinct electronic structure and superconducting gap, layer-dependent behavior and insulator-superconductor transition of the FeSe/SrTiO3 films provide critical information in understanding the superconductivity mechanism of iron-based superconductors. In this paper, we present a brief review of the investigation of the electronic structure and superconductivity of the FeSe superconductor and related systems, with a particular focus on the FeSe films.

  15. Transport Properties of ZnSe- ITO Hetero Junction

    Science.gov (United States)

    Ichibakase, Tsuyoshi

    In this report, ITO(Indium Tin Oxide) was used on the glass substrates as the transparent electrode, and ZnSe layer was prepared by the vacuum deposition on this ITO. Then, the electrical characteristics of this sample were investigated by mans of the electric current transport analysis. The sample that ZnSe was prepared as 3.4 μm in case of ITO-ZnSe sample, has high density level at the junction surface. The ITO-ZnSe junction has two type of diffusion current. However, the ITO-ZnSe sample that ZnSe layer was prepared as 0.1 μm can be assumed as the ohmic contact, and ITO-ZnSe(0.1μm) -CdTe sample shows the avalanche breakdown, and it is considered that the avalanche breakdown occurs in CdTe layer. It is difficult to occur the avalanche breakdown, if ZnSe-CdTe junction has high-density level and CdTe layer has high-density defect. Hence, the ZnSe-CdTe sample that CdTe layer was prepared on ITO-ZnSe(0.1μm) substrate has not high-density level at the junction surface, and the CdTe layer with little lattice imperfection can be prepared. It found that ITO-ZnSe(0.1μm) substrate is available for the II-VI compounds semiconductor device through above analysis result.

  16. 79Se: geochemical and crystallo-chemical retardation mechanisms

    International Nuclear Information System (INIS)

    Chen, F.; Ewing, R.C.

    1999-01-01

    79 Se is a long-lived (1.1 x 10 6 yrs) fission product which is chemically and radiologically toxic. Under Eh-pH conditions typical of oxidative alteration of spent nuclear fuel, selenite, SeO 3 2- or HSeO 3 - or selenate, SeO 4 2- , are the dominant aqueous species of selenium. Because of the high solubility of metal-selenites and metal-selenates and the low adsorption of selenite and selenate aqueous species by geological materials under alkaline conditions, selenium may be highly mobile. However, 79 Se released from altered fuel may become immobilized by incorporation into secondary uranyl phases as low concentration impurities, and this may significantly reduce the mobility of selenium. Analysis and comparison of the known structures of uranyl phases indicate that (SeO 3 ) may substitute for (SiO 3 OH) in structures of α-uranophane and boltwoodite that are expected to be the dominant alteration products of UO 2 in Si-rich groundwater. The substitutions (SeO 3 ) (SiO 3 OH) in sklodowskite, Mg[(UO 2 )(SiO 3 OH)] 2 (H 2 O) 6 and (SeO 3 ) (PO 4 ) in phurcalite, Ca 2 [(UO 2 ) 3 (PO 4 ) 2 O 2 ](H 2 O) 7 , may occur with the eliminated apical anion being substituted for by an H 2 O group, but experimental investigation is required. The close similarity between the sheets in the structures of rutherfordine, [(UO 2 )(CO 3 )] and [(UO 2 )(SeO 3 )] implies that the substitution (SeO 3 ) (CO 3 ) can occur in rutherfordine, and possibly other uranyl carbonates. However, the substitutions: (SeO 3 ) (SiO 4 ) in soddyite and (SeO 3 ) (PO 4 ) in phosphuranylite may disrupt their structural connectivity and are, therefore, unlikely. (orig.)

  17. The MgSeO4-UO2SeO4-H2O system at 25 deg C

    International Nuclear Information System (INIS)

    Serezhkina, L.B.; Serezhkin, V.N.

    1984-01-01

    The method of isothermal solubility at 25 deg C has been used to study MgSeO 4 -UO 2 SeO 4 -H 2 O system. Formation of the new compound Mg 2 (UO 2 ) 3 (SeO 4 ) 5 X32H 2 O, congruently soluble in water is stated. Thermographic and X-ray diffraction investigations of the prepared magnesium selenato-uranylate and products of its dehydration are conducted

  18. XPS, TEM and NRA investigations of Zn(Se,OH)/Zn(OH){sub 2} films on Cu(In,Ga)(S,Se){sub 2} substrates for highly efficient solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Eisele, W.; Ennaoui, A.; Schubert-Bischoff, P.; Giersig, M.; Pettenkofer, C.; Krauser, J.; Lux-Steiner, M. [Hahn-Meitner Inst., Berlin (Germany); Zweigart, S.; Karg, F. [Siemens and Shell Solar, Munich (Germany)

    2003-01-01

    Structural and compositional properties of Zn(Se,OH)/Zn(OH){sub 2} buffer layers deposited by chemical bath deposition(CBD) on Cu(In,Ga)(S,Se){sub 2} (CIGSS) absorbers are investigated. Due to the aqueous nature of the CBD process, oxygen and hydrogen were incorporated into the 'ZnSe' buffer layer mainly in the form of Zn(OH){sub 2} as is shown by X-ray photoelectron spectroscopy and nuclear reaction analysis (NRA) measurements leading to the nomenclature 'Zn(Se,OH)'. Prior to the deposition of Zn(Se,OH), a zinc treatment of the absorber was performed. During that treatment a layer mainly consisting of Zn(OH){sub 2} grew to a thickness of several nanometer. The whole buffer layer therefore consists of a Zn(Se,OH)/Zn(OH){sub 2} structure on CIGSS. Part of the Zn(OH){sub 2} in both layers (i.e. the Zn(Se,OH) and the Zn(OH){sub 2} layer) might be converted into ZnO during measurements or storage. Scanning electron microscopy pictures showed that a complete coverage of the absorber with the buffer layer was achieved. Transmission electron microscopy revealed the different regions of the buffer layer: An amorphous area (possibly Zn(OH){sub 2}) and a partly nanocrystalline area, where lattice planes of ZnSe could be identified. Solar cell efficiencies of ZnO/Zn(Se,OH)/Zn(OH){sub 2}/CIGSS devices exceed 14% (total area).(author)

  19. Dynamical properties and their strain-dependence of ZnSe(ZnSe:N: Zinc-blende and wurtzite

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-06-01

    Full Text Available The lattice dynamical properties of ZnSe and ZnSe with substitutional N incorporation(ZnSe:N are investigated in both the zinc-blend(ZB and wurtzite(WZ structures using first-principles calculations. The optical phonon modes of ZB-ZnSe at the Γ-point locate at 250 cm−1 for LO and 213 cm−1 for TO. The characteristic E2 phonon modes at about 50 cm−1 and the E1 and another E2 phonon modes around 200 cm−1 of WZ-ZnSe are suggested to be the fingerprint for distinguishing the two polytypes of ZnSe. For substitutional N incorporated ZnSe, the N incorporation introduces three new high energy modes above 500 cm−1, and the splitting of them is much larger in the WZ phase than that in ZB phase. The strain dependence of phonon frequency which could be useful for corresponding spectroscopic strain characterization are also studied. The simple linear dependence is determined for ZB-ZnSe, while the situation for WZ-ZnSe looks more complicated.

  20. Formation of ZnSe/Bi2Se3 QDs by surface cation exchange and high photothermal conversion

    Directory of Open Access Journals (Sweden)

    Guozhi Jia

    2015-08-01

    Full Text Available Water-dispersed core/shell structure ZnSe/Bi2Se3 quantum dots were synthesized by ultrasonicwave-assisted cation exchange reaction. Only surface Zn ion can be replaced by Bi ion in ZnSe quantum dots, which lead to the ultrathin Bi2Se3 shell layer formed. It is significance to find to change the crystal of QDs due to the acting of ultrasonicwave. Cation exchange mechanism and excellent photothermal conversion properties are discussed in detail.

  1. Heterojunctions formed by annealing of GaSe and InSe layered crystals in zinc vapor

    Directory of Open Access Journals (Sweden)

    Kudrynskyi Z. R.

    2012-12-01

    Full Text Available The article presents a method of creating heterojunc¬tions based on semiconductors with different lattice types. Substrates manufactured from GaSe and InSe layered crystals were annealed in Zn vapor. This way, n-ZnSe–p-GaSe and n-ZnSe–p-InSe heterojunctions were obtained. The obtained heterojunctions are photo¬sensitive in near and infrared spectral regions. This method opens up greate possibilities of producing heterostructures with a desired sensitivity band.

  2. Flexible one-dimensional carbon-selenium composite nanofibers with superior electrochemical performance for Li-Se/Na-Se batteries

    Science.gov (United States)

    Zeng, Linchao; Wei, Xiang; Wang, Jiaqing; Jiang, Yu; Li, Weihan; Yu, Yan

    2015-05-01

    A facile strategy is developed to synthesis selenium/carbon composites (Se@CNFs-CNT) by co-heating Se powder and electrospun Polyacrylonitrile (PAN)-CNT nanofibers at 600°Cin a sealed vessel. The Se molecules are chemically bonded and physical encapsulated by carbonized PAN-CNT composite (CNFs-CNT), which leads to prevent the dissolution of polyselenide intermediates in carbonate based electrolyte. When directly used as flexible free-standing cathode material for Li-Se batteries in low cost carbonate-based electrolyte, the Se@CNFs-CNT electrode exhibits improved cyclability (517 mAh g-1 after 500 cycles at 0.5 A g-1) and rate capability (485 mAh g-1 at 1 A g-1). Moreover, when tested as sodium batteries, it maintains a reversible capacity of 410 mAh g-1 after 240 cycles at 0.5 A g-1. The superior electrochemical performance (especially at high rates) of Se@CNFs-CNT is attributed to synergistic effect of the additive of CNT, the well confine of Se in the CNFs-CNT matrix through chemical bonding and the 3D interconnected carbon nanofibers (CNFs). This simple yet efficient process thus provides a promising route towards fabrication of a variety of high performance flexible Li-Se and Na-Se batteries.

  3. Third-order nonlinear optical properties of GeSe2-Ga2Se3-PbI2 glasses

    International Nuclear Information System (INIS)

    Tang Gao; Liu Cunming; Luo Lan; Chen Wei

    2010-01-01

    The third-order nonlinear optical (NLO) properties of new selenium-based GeSe 2 -Ga 2 Se 3 -PbI 2 glasses have been measured using the optical Kerr effect (OKE) technique, with picosecond and femtosecond laser pulses. The 0.70GeSe 2 -0.15Ga 2 Se 3 -0.15PbI 2 glass has the largest third-order optical nonlinear susceptibility in GeSe 2 -Ga 2 Se 3 -PbI 2 glass system with χ (3) of 5.28x10 12 esu. In addition, the response time of glasses is sub-picosecond, which is predominantly associated with electron cloud. Local structure of the glasses has been identified by using Raman studies, while the origins of the observed nonlinear optical response are discussed. The [Ge(Ga)Se 4 ] tetrahedral and lone-pair electrons from highly polarizable Pb atom in glasses play an important role in enhanced NLO response. These results as well as their good chemical stability indicate that GeSe 2 -Ga 2 Se 3 -PbI 2 glasses are promising materials for photonic applications of third-order nonlinear optical signal processing.

  4. On the reversibility window in binary As-Se glasses

    International Nuclear Information System (INIS)

    Golovchak, R.; Shpotyuk, O.; Kozdras, A.

    2007-01-01

    Physical ageing effects caused by prolonged natural storage are recorded for binary As x Se 1-x glasses with 0.2≤x 2 Se 3 composition, which network is formed by a so-called self-organized phase, possesses the ideal non-ageing ability

  5. Photoelectrochemical (PEC) studies on CdSe thin films ...

    Indian Academy of Sciences (India)

    TECS

    Thin films of CdSe were deposited by potentiostatic mode on different substrates such as ... trodeposited from aqueous acidic baths, but very few ... washed with liquid detergent (labolene) followed by ul- .... increases the ionic mobilities and hence the conductivity ... A PEC cell of configuration, CdSe/1 M polysulphide/.

  6. Preparation of PbSe nanoparticles by electron beam irradiation

    Indian Academy of Sciences (India)

    A novel method has been developed by electron beam irradiation to prepare PbSe nanoparticles. 2 MeV 10mA GJ-2-II electronic accelerator was used as radiation source. Nanocrystalline PbSe was prepared rapidly at room temperature under atmospheric pressure without any kind of toxic reagents. The structure and ...

  7. Origin of low thermal conductivity in SnSe

    Science.gov (United States)

    Xiao, Yu; Chang, Cheng; Pei, Yanling; Wu, Di; Peng, Kunling; Zhou, Xiaoyuan; Gong, Shengkai; He, Jiaqing; Zhang, Yongsheng; Zeng, Zhi; Zhao, Li-Dong

    2016-09-01

    We provide direct evidence to understand the origin of low thermal conductivity of SnSe using elastic measurements. Compared to state-of-the-art lead chalcogenides Pb Q (Q =Te , Se, S), SnSe exhibits low values of sound velocity (˜1420 m /s ) , Young's modulus (E ˜27.7 GPa ) , and shear modulus (G ˜9.6 GPa ) , which are ascribed to the extremely weak Sn-Se atomic interactions (or bonds between layers); meanwhile, the deduced average Grüneisen parameter γ of SnSe is as large as ˜3.13, originating from the strong anharmonicity of the bonding arrangement. The calculated phonon mean free path (l ˜ 0.84 nm) at 300 K is comparable to the lattice parameters of SnSe, indicating little room is left for further reduction of the thermal conductivity through introducing nanoscale microstructures and microscale grain boundaries. The low elastic properties indicate that the weak chemical bonding stiffness of SnSe generally causes phonon modes softening which eventually slows down phonon propagation. This work provides insightful data to understand the low lattice thermal conductivity of SnSe.

  8. Low temperature magnetic structure of MnSe

    Indian Academy of Sciences (India)

    Abstract. In this paper we report low temperature neutron diffraction studies on MnSe in order to understand the anomalous behaviour of their magnetic and transport prop- erties. Our study indicates that at low temperatures MnSe has two coexisting crystal structures, high temperature NaCl and hexagonal NiAs. NiAs phase ...

  9. Thermoelectric Performance of Na-Doped GeSe

    NARCIS (Netherlands)

    Shaabani, Laaya; Aminorroaya-Yamini, Sima; Byrnes, Jacob; Akbar Nezhad, Ali; Blake, Graeme R

    2017-01-01

    Recently, hole-doped GeSe materials have been predicted to exhibit extraordinary thermoelectric performance owing largely to extremely low thermal conductivity. However, experimental research on the thermoelectric properties of GeSe has received less attention. Here, we have synthesized

  10. Wittgenstein og respekten for det religiøse

    DEFF Research Database (Denmark)

    Albinus, Lars

    2006-01-01

    Fremstilling af den tidlige og den sene Wittgensteins forhold til det religiøse med særligt henblik på tabet af umiddelbarhed.......Fremstilling af den tidlige og den sene Wittgensteins forhold til det religiøse med særligt henblik på tabet af umiddelbarhed....

  11. SE-ENRICHMENT OF CARROT AND ONION VIA FOLIAR APPLICATION

    OpenAIRE

    Kapolna, Emese; Laursen, Kristian H.; Hillestrøm, Peter; Husted, Søren; Larsen, Erik H.

    2008-01-01

    The aim of this work was to study the selenium accumulation in carrot and onion plants using foliar application by sodium selenite and sodium selenate. Furthermore, we aimed at identifying the Se species biosynthesised by onion and carrot plants. The results were used to prepare for production of 77Se enriched plants for an ongoing human absorption study.

  12. Structural characterization of vacuum evaporated ZnSe thin films

    Indian Academy of Sciences (India)

    The lattice parameter, grain size, average internal stress, microstrain, dislocation density and degree of pre- ferred orientation in the film are calculated and correlated with Ts. Keywords. ZnSe thin films; X-ray diffraction; average internal stress; microstrain; dislocation density. 1. Introduction. Thin films of ZnSe has attracted ...

  13. Electrochemical preparation and characterization of CuInSe2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Guillen Arqueros, C.

    1992-01-01

    The objective of this work has been to investigate the electrodeposition as a low-cost, large-area fabrication process to obtain CuInSe 2 this films for efficient photovoltaic devices. this objective entails the elucidation of thin film deposition mechanism, the study of the fundamental properties of electrodeposited material, and also the modification of their physical and chemical parameters for photovoltaic applications. CuInSe 2 thin films have been successfully electrodeposited from a citric was characterized by compositional, structural, electrical, optical and electrochemical measurements, relating their properties with the preparation parameters and also studying the effect of various thermal and chemical treatments. The results showed post-deposition treatment are needed for optimizing these films for solar cells fabrication: first, an annealing in inert atmosphere at temperatures above 400 degrees celsius to obtain a high recrystallization in the chalcopyrite structure, and after a chemical etching in KCN solution to remove secondary phases of Cu x Se and Se which are frequently electrodeposited with the CuInSe 2 . The treated samples showed appropriate photovoltaic activity in a semiconductor-electrolite liquid junction. (author) 193 ref

  14. Scintigraphic evaluation of enterogastric reflux using 75Se-HCAT: Methodology and first clinical observations

    International Nuclear Information System (INIS)

    Furno, A.; Sciarretta, G.; Malaguti, P.; Fagioli, G.; Pozzato, R.

    1987-01-01

    The aim of this study was to assess the possibility of detecting enterogastric reflux (EGR) by 75 Se-HCAT cholescintigraphy. The lowest detectable activity in the gastric area at different concentrations of the radiotracer in the gallbladder was preliminary measured both in a plastic phantom and in an in vivo model. Ten patients were studied after a single oral administration of 1480 KBq 75 Se-HCAT. Gamma camera imaging was carried out for five consecutive days during both fasting and after meal ingestion. In our in vivo model an EGR corresponding to 1% of gallbladder content on day one and 8% on day five was detected. In three out of five patients in whom bile was present in the stomach at endoscopy, 75 Se-HCAT cholescintigraphy demonstrated an EGR, while in three out of five patients in whom endoscopy was negative, 75 Se-HCAT cholescintigrahy detected EGR either during fasting or after meal ingestion. As EGR is not constant, Se-HCAT may be a useful tracer of bile to detect EGR over a prolonged period of time and in different physiological conditions. (orig.)

  15. Scintigraphic evaluation of enterogastric reflux using /sup 75/Se-HCAT: Methodology and first clinical observations

    Energy Technology Data Exchange (ETDEWEB)

    Furno, A; Sciarretta, G; Malaguti, P; Fagioli, G; Pozzato, R

    1987-08-01

    The aim of this study was to assess the possibility of detecting enterogastric reflux (EGR) by /sup 75/Se-HCAT cholescintigraphy. The lowest detectable activity in the gastric area at different concentrations of the radiotracer in the gallbladder was preliminary measured both in a plastic phantom and in an in vivo model. Ten patients were studied after a single oral administration of 1480 KBq /sup 75/Se-HCAT. Gamma camera imaging was carried out for five consecutive days during both fasting and after meal ingestion. In our in vivo model an EGR corresponding to 1% of gallbladder content on day one and 8% on day five was detected. In three out of five patients in whom bile was present in the stomach at endoscopy, /sup 75/Se-HCAT cholescintigraphy demonstrated an EGR, while in three out of five patients in whom endoscopy was negative, /sup 75/Se-HCAT cholescintigrahy detected EGR either during fasting or after meal ingestion. As EGR is not constant, Se-HCAT may be a useful tracer of bile to detect EGR over a prolonged period of time and in different physiological conditions.

  16. A Review of SnSe: Growth and Thermoelectric Properties

    Science.gov (United States)

    Nguyen, Van Quang; Kim, Jungdae; Cho, Sunglae

    2018-04-01

    SnSe is a 2D semiconductor with an indirect energy gap of 0.86 - 1 eV; it is widely used in solar cell, optoelectronics, and electronic device applications. Recently, SnSe has been considered as a robust candidate for energy conversion applications due to its high thermoelectric performance ( ZT = 2.6 in p-type and 2.2 in n-type), which is assigned mainly to its anhamornic bonding leading to an ultralow thermal conductivity. In this review, we first discuss the crystalline and electronic structures of SnSe and the source of its p-type characteristic. Then, some typical single crystal and polycrystal growth techniques, as well as an epitaxial thin film growth technique, are outlined. The reported thermoelectric properties of SnSe grown by using each technique are also reviewed. Finally, we will describe some remaining issues concerning the use of SnSe for thermoelectric applications.

  17. Immobilization of Se and U by iron sulfides

    International Nuclear Information System (INIS)

    Kang Mingliang; Ma Bin; Yang Zhuanwei; Liu Chunli; Chen Fanrong

    2014-01-01

    Both uranium and selenium are redox-sensitive, and can occur in several oxidation states. In reducing environments, they exist as insoluble forms. Therefore, reductive precipitation is the most effective way to immobilize U and Se. The interaction of aqueous Se (IV) and uranylwithiron sulfidesweresystematically investigated in light of thermodynamic calculations, X-ray Absorption Spectroscopy (XAS), and X-ray Photoelectron Spectroscopy (XPS). The results from the speciation study revealed that the reduction product was Se (O) when natural pyrite and pyrrhotitereacted with Se (IV), although FeSe 2 is the thermodynamically predicted product from nearly neural to alkaline conditions. This discrepancy is attributed to the oxidizing ability of Se (IV) towards FeSe 2 , of which produce the insoluble Se (0) as the stable product in short-term experiments. In contrast to the thermodynamic calculations, with a reaction product of mixed U (IV) and U (VI) (e.g., U 3 O 8 ), redox reaction was observed only at pH ∼ 8.5 and ∼ 4.5 for U (VI) reduction by nanosized pyrite and natural pyrite, respectively. We proposed that oxidation of pyrite needs an intermediate (e.g., Fe 2+ ), and the reaction between the uranyl and the intermediate is thermodynamically or kinetically limited. Moreover, trace elements generally held within pyrite structure can also greatly influence its reactivity. This study demonstrated that reaction kinetics play a significant role on the reaction product. From a geological time scale, Se and U are likely to be immobilized by iron sulfides via the form of FeSe 2 and UO 2 . (authors)

  18. AgSbSe2 and AgSb(S,Se)2 thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Garza, J.G.; Shaji, S.; Rodriguez, A.C.; Das Roy, T.K.; Krishnan, B.

    2011-01-01

    Silver antimony selenide (AgSbSe 2 ) thin films were prepared by heating sequentially deposited multilayers of antimony sulphide (Sb 2 S 3 ), silver selenide (Ag 2 Se), selenium (Se) and silver (Ag). Sb 2 S 3 thin film was prepared from a chemical bath containing SbCl 3 and Na 2 S 2 O 3 , Ag 2 Se from a solution containing AgNO 3 and Na 2 SeSO 3 and Se thin films from an acidified solution of Na 2 SeSO 3 , at room temperature on glass substrates. Ag thin film was deposited by thermal evaporation. The annealing temperature was 350 deg. C in vacuum (10 -3 Torr) for 1 h. X-ray diffraction analysis showed that the thin films formed were polycrystalline AgSbSe 2 or AgSb(S,Se) 2 depending on selenium content in the precursor films. Morphology and elemental analysis of these films were done using scanning electron microscopy and energy dispersive X-ray spectroscopy. Optical band gap was evaluated from the UV-visible absorption spectra of these films. Electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: glass/ITO/CdS/AgSbSe 2 /Al was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this structure showed V oc = 435 mV and J sc = 0.08 mA/cm 2 under illumination using a tungsten halogen lamp. Preparation of a photovoltaic structure using AgSbSe 2 as an absorber material by a non-toxic selenization process is achieved.

  19. Short and medium range structures of 80GeSe2–20Ga2Se3 chalcogenide glasses

    Science.gov (United States)

    Petracovschi, Elena; Calvez, Laurent; Cormier, Laurent; Le Coq, David; Du, Jincheng

    2018-05-01

    The short and medium range structures of 80GeSe2–20Ga2Se3 (or Ge23.5Ga11.8Se64.7) chalcogenide glasses have been studied by combining ab initio molecular dynamics (AIMD) simulations and experimental neutron diffraction studies. The structure factor and total correlation function were calculated from glass structures generated from AIMD simulations and compared with neutron diffraction experiments showing reasonable agreement. The atomic structures of ternary chalcogenide glasses were analyzed in detail, and it was found that gallium atoms are four-fold coordinated by selenium (Se) and form [GaSe4] tetrahedra. Germanium atoms on average also have four-fold coordination, among which Se is 3.5 with the remaining being Ge–Ge homo-nuclear bonds. Ga and Ge tetrahedra link together mainly through corner-sharing and some edge-sharing of Se. No homo-nuclear bonds were observed among Ga atoms or between Ge and Ga. In addition, Se–Se homo-nuclear bonds and Se chains with various lengths were observed. A small fraction of Se atom triclusters that bond to three cations of Ge and Ga were also observed, confirming earlier proposals from 77Se solid state nuclear magnetic resonance studies. Furthermore, the electronic structures of ternary chalcogenide glasses were studied in terms of atomic charge and electronic density of states in order to gain insights into the chemical bonding and electronic properties, as well as to provide an explanation of the observed atomic structures in these ternary chalcogenide glasses.

  20. AgSbSe{sub 2} and AgSb(S,Se){sub 2} thin films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Garza, J.G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Shaji, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Facultad de Ingenieria Mecanica y Electrica, CIIDIT - Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Rodriguez, A.C.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Krishnan, B., E-mail: kbindu_k@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon (Mexico); Facultad de Ingenieria Mecanica y Electrica, CIIDIT - Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-10-01

    Silver antimony selenide (AgSbSe{sub 2}) thin films were prepared by heating sequentially deposited multilayers of antimony sulphide (Sb{sub 2}S{sub 3}), silver selenide (Ag{sub 2}Se), selenium (Se) and silver (Ag). Sb{sub 2}S{sub 3} thin film was prepared from a chemical bath containing SbCl{sub 3} and Na{sub 2}S{sub 2}O{sub 3}, Ag{sub 2}Se from a solution containing AgNO{sub 3} and Na{sub 2}SeSO{sub 3} and Se thin films from an acidified solution of Na{sub 2}SeSO{sub 3}, at room temperature on glass substrates. Ag thin film was deposited by thermal evaporation. The annealing temperature was 350 deg. C in vacuum (10{sup -3} Torr) for 1 h. X-ray diffraction analysis showed that the thin films formed were polycrystalline AgSbSe{sub 2} or AgSb(S,Se){sub 2} depending on selenium content in the precursor films. Morphology and elemental analysis of these films were done using scanning electron microscopy and energy dispersive X-ray spectroscopy. Optical band gap was evaluated from the UV-visible absorption spectra of these films. Electrical characterizations were done using Hall effect and photocurrent measurements. A photovoltaic structure: glass/ITO/CdS/AgSbSe{sub 2}/Al was formed, in which CdS was deposited by chemical bath deposition. J-V characteristics of this structure showed V{sub oc} = 435 mV and J{sub sc} = 0.08 mA/cm{sup 2} under illumination using a tungsten halogen lamp. Preparation of a photovoltaic structure using AgSbSe{sub 2} as an absorber material by a non-toxic selenization process is achieved.

  1. Charge separation in contact systems with CdSe quantum dot layers

    International Nuclear Information System (INIS)

    Zillner, Elisabeth Franziska

    2013-01-01

    Quantum dot (QD) solar cells are a fast developing area in the field of solution processed photovoltaics. Central aspects for the application of QDs in solar cells are separation and transport of charge carriers in the QD layers and the formation of charge selective contacts. Even though efficiencies of up to 7% were reached in QD solar cells, these processes are not yet fully understood. In this thesis the mechanisms of charge separation, transport and recombination in CdSe QD layers and layer systems were studied. Charge separation was measured via surface photovoltage (SPV) at CdSe QD layers with thicknesses in the range of monolayers. To determine the influence of interparticle distance of QDs and trap states on the surface of QDs on charge separation, QDs with four different surfactant layers were studied. Layers of CdSe QDs were prepared on ITO, Si, SiO 2 and CdS by dip coating under inert atmosphere. The layers were characterized by Rutherford backscattering spectrometry, UV-vis spectroscopy, step profilometry and scanning electron microscopy to determine the areal density, the absorption and thickness of CdSe QD monolayers. SPV measurements show that initial charge separation from the CdSe QDs on ITO only happened from the fi rst monolayer of QDs. Electrons, photo-excited in the fi rst monolayer of CdSe QDs, were trapped on the ITO surface. The remaining free holes were trapped in surface states and/or diffused into the neighboring QD layers. The thick surfactant layer (∼ 1.6 nm) of pristine QDs had to be reduced by washing and/or ligand exchange for separation of photo-excited charge carriers. Both, interparticle distance and trap density, influenced the processes of charge separation and recombination. SPV transients of CdSe monolayers could be described by a single QD approximation model, based on Miller-Abrahams hopping of holes between the delocalized excitonic state, traps on the surface of the QD and the filled trap on the ITO surface

  2. Charge separation in contact systems with CdSe quantum dot layers

    Energy Technology Data Exchange (ETDEWEB)

    Zillner, Elisabeth Franziska

    2013-03-06

    Quantum dot (QD) solar cells are a fast developing area in the field of solution processed photovoltaics. Central aspects for the application of QDs in solar cells are separation and transport of charge carriers in the QD layers and the formation of charge selective contacts. Even though efficiencies of up to 7% were reached in QD solar cells, these processes are not yet fully understood. In this thesis the mechanisms of charge separation, transport and recombination in CdSe QD layers and layer systems were studied. Charge separation was measured via surface photovoltage (SPV) at CdSe QD layers with thicknesses in the range of monolayers. To determine the influence of interparticle distance of QDs and trap states on the surface of QDs on charge separation, QDs with four different surfactant layers were studied. Layers of CdSe QDs were prepared on ITO, Si, SiO{sub 2} and CdS by dip coating under inert atmosphere. The layers were characterized by Rutherford backscattering spectrometry, UV-vis spectroscopy, step profilometry and scanning electron microscopy to determine the areal density, the absorption and thickness of CdSe QD monolayers. SPV measurements show that initial charge separation from the CdSe QDs on ITO only happened from the fi rst monolayer of QDs. Electrons, photo-excited in the fi rst monolayer of CdSe QDs, were trapped on the ITO surface. The remaining free holes were trapped in surface states and/or diffused into the neighboring QD layers. The thick surfactant layer ({approx} 1.6 nm) of pristine QDs had to be reduced by washing and/or ligand exchange for separation of photo-excited charge carriers. Both, interparticle distance and trap density, influenced the processes of charge separation and recombination. SPV transients of CdSe monolayers could be described by a single QD approximation model, based on Miller-Abrahams hopping of holes between the delocalized excitonic state, traps on the surface of the QD and the filled trap on the ITO surface

  3. Photoacoustic spectroscopy of thin films of As2S3, As2Se3 and GeSe2

    Indian Academy of Sciences (India)

    Photoacoustic spectroscopy (PAS) is one of the important branches of spectroscopy, which enables one to detect light-induced heat production following the absorption of pulsed radiation by the sample. As2S3, As2Se3 and GeSe2 exhibit a wide variety of photo-induced phenomena that enable them to be used as optical ...

  4. Fundamental absorption edge in CuIn5Se8 and CuGa3Se5 single crystals

    International Nuclear Information System (INIS)

    Leon, M.; Merino, J.M.; Levcenko, S.; Nateprov, A.; Tezlevan, V.; Arushanov, E.; Syrbu, N.N.

    2006-01-01

    Optical absorption spectra of CuIn 5 Se 8 and CuGa 3 Se 5 single crystals have been investigated. The energy gap E g for CuIn 5 Se 8 (CuGa 3 Se 5 ) was found to be varied from 1.27(1.79) to 1.21(1.71) eV in the temperature range between 10 and 300 K. The temperature dependence of E g was studied by means of the Einstein model and the Paessler model. The Einstein temperature {222(267)K}, the Debye temperature {310(380)K}, a dimensionless constant related to the electron-phonon coupling {1.62(2.65)} as well as an effective energy {20 (24) meV} and a cut-off phonon energy {35(39) meV} have been estimated for CuIn 5 Se 8 (CuGa 3 Se 5 ). It was also found that the major contribution of phonons to the shift of E g versus temperature in CuIn 5 Se 8 (CuGa 3 Se 5 ) is mainly from optical phonons. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  5. Cs2SeO4-UO2SeO4-H2O system at 25 deg C

    International Nuclear Information System (INIS)

    Serezhkina, L.B.; Serezhkin, V.N.

    1987-01-01

    Using the method of isothermal solubility at 25 deg C the interaction of cesium and uranyl selenates in aqueous solution is studied. Formation of congruently soluble Cs 2 UO 2 (SeO 4 ) 2 x2H 2 O and Cs 2 (UO 2 ) 2 x(SeO 4 ) 3 is ascertained, their crystallographic characteristics being determined

  6. Detrital zircon study along the Tsangpo River, SE Tibet

    Science.gov (United States)

    Liang, Y.; Chung, S.; Liu, D.; O'Reilly, S. Y.; Chu, M.; Ji, J.; Song, B.; Pearson, N. J.

    2004-12-01

    The interactions among tectonic uplift, river erosion and alluvial deposition are fundamental processes that shape the landscape of the Himalayan-Tibetan orogen since its creation from early Cenozoic time. To better understand these processes around the eastern Himalayan Syntaxis, we conducted a study by systematic sampling riverbank sediments along the Tsangpo River, SE Tibet. Detrital zircons separated from the sediments were subjected to U-Pb dating by the SHRIMP II at the Beijing SHRIMP Center and then in-situ measurements of Hf isotope ratios using LA-MC-ICPMS at GEMOC. These results, together with U-Pb ages and Hf isotope data that we recently obtained for the Transhimalayan plutonic and surrounding basement rocks, allow a more quantitative examination of the provenance or protosource areas for the river sediments. Consequently, the percentage inputs from these source areas can be estimated. Our study indicates that, before the Tsangpo River flows into the Namche Barwa Syntaxis of the eastern Himalayas where the River forms a 180° Big Bend gorge and crosscuts the Himalayan sequences, the Gangdese batholith that crops out just north of the River appear to be an overwhelming source accounting for ˜50 % of the bank sediments. The Tethyan Himalayan sequences south of the River are the second important source, with an input of ˜25 %. The proportion of sediment supply changes after the River enters the Big Bend gorge and turns to south: ˜25 % of detrital zircons are derived from the Greater Himalayas so that the input from the Tethyan Himalayas decreases (< 10 %) despite those from the Gangdese batholith remains high ( ˜40 %). Comparing with the sediment budget of the Brahmaputra River in the downstream based on literature Sr, Nd and Os isotope information, which suggests dominant ( ˜90-60 %) but subordinate ( ˜10-40 %) contributions by the (Greater and Lesser) Himalayan and Tibetan (including Tethyan Himalayan) rocks, respectively, the change is interpreted

  7. Electrochemical synthesis of nanostructured Se-doped SnS: Effect of Se-dopant on surface characterizations

    International Nuclear Information System (INIS)

    Kafashan, Hosein; Azizieh, Mahdi; Balak, Zohre

    2017-01-01

    Highlights: • Nanostructured SnS_1_-_xSe_x thin films were prepared by using electrodeposition method. • The XRD patterns obviously showed that the synthesized films were polycrystalline. • The PL spectra of SnS_1_-_xSe_x thin films showed four emission peaks. • The UV–vis spectra shows a variation in the optical band gap energy of SnS_1_-_xSe_x thin films from 1.22 to 1.65 eV. • SnS_1_-_xSe_x thin films would be suitable for use as absorber layers. - Abstract: SnS_1_-_xSe_x nanostructures with different Se-dopant concentrations were deposited on fluorine doped tin oxide (FTO) substrate through cathodic electrodeposition technique. The pH, temperature, applied potential (E), and deposition time remained were 2.1, 60 °C, −1 V, and 30 min, respectively. SnS_1_-_xSe_x nanostructures were characterized using X-ray diffraction (XRD), field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), room temperature photoluminescence (PL), and UV–vis spectroscopy. The XRD patterns revealed that the SnS_1_-_xSe_x nanostructures were polycrystalline with orthorhombic structure. FESEM showed various kinds of morphologies in SnS_1_-_xSe_x nanostructures due to Se-doping. PL and UV–vis spectroscopy were used to evaluate the optical properties of SnS_1_-_xSe_x thin films. The PL spectra of SnS_1_-_xSe_x nanostructures displayed four emission peaks, those are a blue, a green, an orange, and a red emission. UV–vis spectra showed that the optical band gap energy (E_g) of SnS_1_-_xSe_x nanostructures varied between 1.22–1.65 eV, due to Se-doping.

  8. Electrochemical synthesis of nanostructured Se-doped SnS: Effect of Se-dopant on surface characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Kafashan, Hosein, E-mail: hosein840521@gmail.com; Azizieh, Mahdi; Balak, Zohre

    2017-07-15

    Highlights: • Nanostructured SnS{sub 1-x}Se{sub x} thin films were prepared by using electrodeposition method. • The XRD patterns obviously showed that the synthesized films were polycrystalline. • The PL spectra of SnS{sub 1-x}Se{sub x} thin films showed four emission peaks. • The UV–vis spectra shows a variation in the optical band gap energy of SnS{sub 1-x}Se{sub x} thin films from 1.22 to 1.65 eV. • SnS{sub 1-x}Se{sub x} thin films would be suitable for use as absorber layers. - Abstract: SnS{sub 1-x}Se{sub x} nanostructures with different Se-dopant concentrations were deposited on fluorine doped tin oxide (FTO) substrate through cathodic electrodeposition technique. The pH, temperature, applied potential (E), and deposition time remained were 2.1, 60 °C, −1 V, and 30 min, respectively. SnS{sub 1-x}Se{sub x} nanostructures were characterized using X-ray diffraction (XRD), field emission scanning electron microcopy (FESEM), energy dispersive X-ray spectroscopy (EDX), room temperature photoluminescence (PL), and UV–vis spectroscopy. The XRD patterns revealed that the SnS{sub 1-x}Se{sub x} nanostructures were polycrystalline with orthorhombic structure. FESEM showed various kinds of morphologies in SnS{sub 1-x}Se{sub x} nanostructures due to Se-doping. PL and UV–vis spectroscopy were used to evaluate the optical properties of SnS{sub 1-x}Se{sub x} thin films. The PL spectra of SnS{sub 1-x}Se{sub x} nanostructures displayed four emission peaks, those are a blue, a green, an orange, and a red emission. UV–vis spectra showed that the optical band gap energy (E{sub g}) of SnS{sub 1-x}Se{sub x} nanostructures varied between 1.22–1.65 eV, due to Se-doping.

  9. SeLeCT: a lexical cohesion based news story segmentation system

    OpenAIRE

    Stokes, Nicola; Carthy, Joe; Smeaton, Alan F.

    2004-01-01

    In this paper we compare the performance of three distinct approaches to lexical cohesion based text segmentation. Most work in this area has focused on the discovery of textual units that discuss subtopic structure within documents. In contrast our segmentation task requires the discovery of topical units of text i.e., distinct news stories from broadcast news programmes. Our approach to news story segmentation (the SeLeCT system) is based on an analysis of lexical cohesive strength between ...

  10. Inkjet?Printed Cu2ZnSn(S, Se)4 Solar Cells

    OpenAIRE

    Lin, Xianzhong; Kavalakkatt, Jaison; Lux?Steiner, Martha Ch.; Ennaoui, Ahmed

    2015-01-01

    Cu2ZnSn(S, Se)4?based solar cells with total area (0.5 cm2) power conversion efficiency of 6.4% are demonstrated from thin film absorbers processed by inkjet printing technology of Cu?Zn?Sn?S precursor ink followed by selenization. The device performance is limited by the low fill factor, which is due to the high series resistance.

  11. Inkjet-Printed Cu2ZnSn(S, Se)4 Solar Cells.

    Science.gov (United States)

    Lin, Xianzhong; Kavalakkatt, Jaison; Lux-Steiner, Martha Ch; Ennaoui, Ahmed

    2015-06-01

    Cu 2 ZnSn(S, Se) 4 -based solar cells with total area (0.5 cm 2 ) power conversion efficiency of 6.4% are demonstrated from thin film absorbers processed by inkjet printing technology of Cu-Zn-Sn-S precursor ink followed by selenization. The device performance is limited by the low fill factor, which is due to the high series resistance.

  12. Investigation of short and ballistic coupling in vertical NbSe2 - graphene - NbSe2 Josephson junctions

    Science.gov (United States)

    Kim, Minsoo; Park, Geon-Hyoung; Yi, Jongyoon; Lee, Jae Hyeong; Park, Jinho; Lee, Hu-Jong

    2H-NbSe2 is a layered two-dimensional superconducting material, which can be constructed into a van der Waals heterostructure with versatile functionality. Here we fabricated a vertically stacked NbSe2 - graphene - NbSe2 heterostructure by the dry transfer technique, where defect-free contact via van der Waals force provides the high interfacial transparency. Insertion of an atomically thin graphene layer between two NbSe2 flakes ensures the formation of highly coherent proximity Josephson coupling. Observed temperature dependence of the junction critical current (Ic) and large value of IcRn product (as large as 2.3ΔNbSe 2) reveal the short and ballistic Josephson coupling characteristics. Large junction critical current density of 104 A/cm2, multiple Andreev reflection in the subgap structure of the differential conductance, and magnetic field modulation of Ic also suggest the strong Josephson coupling via the graphene layer.

  13. ¿Qué se juega al jugar un juego?

    Directory of Open Access Journals (Sweden)

    Kalejman, Cecilia

    2012-06-01

    Full Text Available En el presente artículo se considera el juego en relación a la niñez. Se indaga acerca del papel que juega el juego en la niñez intentando responder a diversas preguntas, entre ellas la más importante: ¿Qué significa jugar? A lo largo de esta etapa del desarrollo en que comienza a constituirse la subjetividad del individuo el juego constituye, sin dudas, un factor central, una herramienta fundamental en el desarrollo. Juego no es sólo el juego dramático, también consideramos para nuestro análisis aquellas modalidades de juego que se transmiten de generación en generación, juegos de construcción, los dibujos, teniendo en cuenta asimismo los objetos utilizados en los juegos, los contenidos de los mismos, los espacios en los que se desarrollan. Se piensa y se interpreta al juego, como un derecho y como un modo de expresión del niño, se finaliza este desarrollo con una conclusión acera del juego y el espacio que ocupa en la vida cotidiana.

  14. Synthesis of ZnSe and ZnSe:Cu quantum dots by a room temperature photochemical (UV-assisted) approach using Na2 SeO3 as Se source and investigating optical properties.

    Science.gov (United States)

    Khafajeh, R; Molaei, M; Karimipour, M

    2017-06-01

    In this study, ZnSe and ZnSe:Cu quantum dots (QDs) were synthesized using Na 2 SeO 3 as the Se source by a rapid and room temperature photochemical (UV-assisted) approach. Thioglycolic acid (TGA) was employed as the capping agent and UV illumination activated the chemical reactions. Synthesized QDs were successfully characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) and UV-visible (UV-vis) spectroscopy, Fourier transform-infrared (FT-IR), and energy dispersive X-ray spectroscopy (EDX). XRD analysis demonstrated the cubic zinc blend phase QDs. TEM images indicated that round-shaped particles were formed, most of which had a diameter of about 4 nm. The band gap of the ZnSe QDs was higher than that for ZnSe in bulk. PL spectra indicated an emission with three peaks related to the excitonic, surface trap states and deep level (DL) states. The band gap and QD emission were tunable only by UV illumination time during synthesis. ZnSe:Cu showed green emission due to transition of electrons from the Conduction band (CB) or surface trap states to the 2 T 2 acceptor levels of Cu 2 + . The emission was increased by increasing the Cu 2 + ion concentration, such that the optimal value of PL intensity was obtained for the nominal mole ratio of Cu:Zn 1.5%. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Novel mechanical behaviors of wurtzite CdSe nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Bing [Shanghai Normal University, Department of Physics (China); Chen, Li [MCPHS University, School of Arts and Sciences (United States); Xie, Yiqun; Feng, Jie; Ye, Xiang, E-mail: yexiang@shnu.edu.cn [Shanghai Normal University, Department of Physics (China)

    2015-09-15

    As an important semiconducting nanomaterial, CdSe nanowires have attracted much attention. Although many studies have been conducted in the electronic and optical properties of CdSe NWs, the mechanical properties of Wurtzite (WZ) CdSe nanowires remain unclear. Using molecular dynamics simulations, we have studied the tensile mechanical properties and behaviors of [0001]-oriented Wurtzite CdSe nanowires. By monitoring the stretching processes of CdSe nanowires, three distinct structures are found: the WZ wire, a body-centered tetragonal structure with four-atom rings (denoted as BCT-4), and a structure that consists of ten-atom rings with two four-atom rings (denoted as TAR-4) which is observed for the first time. Not only the elastic tensile characteristics are highly reversible under unloading, but a reverse transition between TAR-4 and BCT-4 is also observed. The stretching processes also have a strong dependence on temperature. A tubular structure similar to carbon nanotubes is observed at 150 K, a single-atom chain is formed at 300, 350 and 450 K, and a double-atom chain is found at 600 K. Our findings on tensile mechanical properties of WZ CdSe nanowires does not only provide inspiration to future study on other properties of CdSe nanomaterials but also help design and build efficient nanoscale devices.

  16. CdSe/ZnSe quantum dot structures grown by molecular beam epitaxy with a CdTe submonolayer stressor

    International Nuclear Information System (INIS)

    Sedova, I. V.; Lyublinskaya, O. G.; Sorokin, S. V.; Sitnikova, A. A.; Toropov, A. A.; Donatini, F.; Dang, Si Le; Ivanov, S. V.

    2007-01-01

    A procedure for formation of CdSe quantum dots (QDs) in a ZnSe matrix is suggested. The procedure is based on the introduction of a CdTe submonolayer stressor deposited on the matrix surface just before deposition of the material of the QDs. (For CdTe/ZnSe structure, the relative lattice mismatch is Δa/a ∼ 14%.) The stressor forms small strained islands at the ZnSe surface, thus producing local fields of high elastic stresses controlling the process of the self-assembling of the QDs. According to the data of transmission electron microscopy, this procedure allows a considerable increase in the surface density of QDs, with a certain decrease in their lateral dimensions (down to 4.5 ± 1.5 nm). In the photoluminescence spectra, a noticeable (∼150 meV) shift of the peak to longer wavelengths from the position of the reference CdSe/ZnSe QD structure is observed. The shift is due to some transformation of the morphology of the QDs and an increase in the Cd content in the QDs. Comprehensive studies of the nanostructures by recording and analyzing the excitation spectra of photoluminescence, the time-resolved photoluminescence spectra, and the cathodoluminescence spectra show that the emission spectra involve two types of optical transitions, namely, the type-I transitions in the CdSeTe/ZnSe QDs and the type-II transitions caused mainly by the low cadmium content (Zn,Cd)(Se,Te)/ZnSe layer formed between the QDs

  17. Copper Selenidophosphates Cu4P2Se6, Cu4P3Se4, Cu4P4Se3, and CuP2Se, Featuring Zero-, One-, and Two-Dimensional Anions.

    Science.gov (United States)

    Kuhn, Alexander; Schoop, Leslie M; Eger, Roland; Moudrakovski, Igor; Schwarzmüller, Stefan; Duppel, Viola; Kremer, Reinhard K; Oeckler, Oliver; Lotsch, Bettina V

    2016-08-15

    Five new compounds in the Cu/P/Se phase diagram have been synthesized, and their crystal structures have been determined. The crystal structures of these compounds comprise four previously unreported zero-, one-, and two-dimensional selenidophosphate anions containing low-valent phosphorus. In addition to two new modifications of Cu4P2Se6 featuring the well-known hexaselenidohypodiphosphate(IV) ion, there are three copper selenidophosphates with low-valent P: Cu4P3Se4 contains two different new anions, (i) a monomeric (zero-dimensional) selenidophosphate anion [P2Se4](4-) and (ii) a one-dimensional selenidophosphate anion [Formula: see text], which is related to the well-known gray-Se-like [Formula: see text] Zintl anion. Cu4P4Se3 contains one-dimensional [Formula: see text] polyanions, whereas CuP2Se contains the 2D selenidophosphate [Formula: see text] polyanion. It consists of charge-neutral CuP2Se layers separated by a van der Waals gap which is very rare for a Zintl-type phase. Hence, besides black P, CuP2Se constitutes a new possible source of 2D oxidized phosphorus containing layers for intercalation or exfoliation experiments. Additionally, the electronic structures and some fundamental physical properties of the new compounds are reported. All compounds are semiconducting with indirect band gaps of the orders of around 1 eV. The phases reported here add to the structural diversity of chalcogenido phosphates. The structural variety of this family of compounds may translate into a variety of tunable physical properties.

  18. Social Set Visualizer (SoSeVi) II

    DEFF Research Database (Denmark)

    Flesch, Benjamin; Vatrapu, Ravi

    2016-01-01

    This paper reports the second iteration of the Social Set Visualizer (SoSeVi), a set theoretical visual analytics dashboard of big social data. In order to further demonstrate its usefulness in large-scale visual analytics tasks of individual and collective behavior of actors in social networks......, the current iteration of the Social Set Visualizer (SoSeVi) in version II builds on recent advancements in visualizing set intersections. The development of the SoSeVi dashboard involved cutting-edge open source visual analytics libraries (D3.js) and creation of new visualizations such as of actor mobility...

  19. Se interlayer in CIGS absorption layer for solar cell devices

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung-Kyu; Sim, Jae-Kwan [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Kissinger, N.J. Suthan [Department of General Studies, Physics Group, Jubail University College, Royal Commission for Jubail, Jubail 10074 (Saudi Arabia); Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of); Lee, Cheul-Ro, E-mail: crlee7@jbnu.ac.kr [Semiconductor Materials Process Laboratory, School of Advanced Materials Engineering, Research Center for Advanced Materials Development, Chonbuk National University, Deokjin-Dong 664-14, Jeonju 561-756 (Korea, Republic of)

    2015-06-05

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V{sub oc}. Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance.

  20. Reversible ultrafast melting in bulk CdSe

    International Nuclear Information System (INIS)

    Wu, Wenzhi; He, Feng; Wang, Yaguo

    2016-01-01

    In this work, transient reflectivity changes in bulk CdSe have been measured with two-color femtosecond pump-probe spectroscopy under a wide range of pump fluences. Three regions of reflectivity change with pump fluences have been consistently revealed for excited carrier density, coherent phonon amplitude, and lattice temperature. For laser fluences from 13 to 19.3 mJ/cm 2 , ultrafast melting happens in first several picoseconds. This melting process is purely thermal and reversible. A complete phase transformation in bulk CdSe may be reached when the absorbed laser energy is localized long enough, as observed in nanocrystalline CdSe

  1. Development of conductive nanotemplates on ZnSe

    International Nuclear Information System (INIS)

    Monaico, Eduard; Tiginyanu, Ion; Colibaba, Gleb; Nedeoglo, D.D.; Cojocaru, Ala; Foell, Helmut

    2011-01-01

    We demonstrate the possibility to fabricate arrays of pores oriented perpendicular and parallel to the top surface of the ZnSe nanotemplate. The control of material conductivity allows one to produce porous ZnSe samples with the mean pore diameter and characteristic skeleton wall thickness from several hundreds of nanometers to about 15 nm. In addition, electrochemical treatment of ZnSe single crystals using photoresist masks allows one to prepare buried porous structures with pores directed parallel to the top template surface, which is especially important for photonic applications.

  2. Magnetic study of Fe-doped CdSe nanomaterials

    International Nuclear Information System (INIS)

    Das, Sayantani; Banerjee, Sourish; Sinha, T. P.

    2016-01-01

    Nanoparticles of pure and iron (50 %) doped cadmium selenide (CdSe) have been synthesized by soft chemical route. EDAX analysis supports the inclusion of Fe into CdSe nanoparticles. The average particle size of pure and doped CdSe is found to be ∼50 nm from scanning electron microscopy (SEM). Magnetization of the samples are measured under the field cooled (FC) and zero field cooled (ZFC) modes in the temperature range from 5K to 300K applying a magnetic field of 500Oe. Field dependent magnetization (M-H) measurement indicates presence of room temperature (RT) paramagnetism and low temperature (5K) ferromagnetism of the sample.

  3. Polybutylcyanoacrylate nanoparticles for the delivery of [75Se]norcholestenol

    International Nuclear Information System (INIS)

    Kreuter, J.; Wilson, C.G.

    1983-01-01

    Polybutylcyanoacrylate nanoparticles have been used for the intravenous and intramuscular administration of a steroidal material ([ 75 Se]norcholestenol) to the rabbit. Whole body profiles of 75 Se, obtained using a gamma camera over a period of 30 days, show that the [ 75 Se]norcholestenol is retained for a longer period of time with the nanoparticle system than for the control system where the drug was dissolved in a micellar system. In vitro dialysis experiments indicate that the thermodynamic activity of the drug can be increased by its incorporation within nanoparticles. This increased activity may affect the distribution of the drug into body tissues. (Auth.)

  4. Se interlayer in CIGS absorption layer for solar cell devices

    International Nuclear Information System (INIS)

    Lee, Seung-Kyu; Sim, Jae-Kwan; Kissinger, N.J. Suthan; Song, Il-Seok; Kim, Jin-Soo; Baek, Byung-Joon; Lee, Cheul-Ro

    2015-01-01

    Highlights: • Se interlayer is deposited between the CuGa and CuIn/In/Mo/STS stacked layer. • Both CIG precursor layers were selenized at 500 °C for 1 h. • SIMS depth profile shows that Ga distribution is uniform by Se interlayer. • The efficiency was improved for the CIGS solar cell by Se interlayer. - Abstract: A CIGS absorber layer with high gallium contents in the space-charge region can reduce the carrier recombination and improve the open circuit voltage V oc . Therefore, controlling Ga grading on top of CIGS thin film solar cells is the main objective of this experiment. To reduce Selenium (Se) vacancy, it is important that the diffusion of Ga elements into Se vacancy between Mo back contact and CIGS absorption layer would be controlled. In order to reduce Se vacancy and confirm Ga inter-diffusion, two CIGS solar cells were fabricated by converting CIG precursor with and without Se interlayer. The copper-indium metallic precursors were fabricated corresponding to the sequence CuIn/In/Mo/STS on stainless steel (STS) substrates by sequential direct current magnetron sputtering while Se layer was evaporated by rapid thermal annealing (RTA) system to obtain a Se/CuIn/In/Mo/STS stack. CuGa precursor layer was also fabricated on the Se/CuIn/In/Mo/STS stack. Finally, both CuGa/Se/CuIn/In/Mo/STS and CuGa/CuIn/In/Mo/STS stacks were selenized at 500 °C for 1 h. It was clearly observed from the secondary ion mass spectroscopy (SIMS) and X-ray diffraction (XRD) that there was a change between the fabricated CIGS absorption layers and the amount of Ga elements. Furthermore, the Ga elements gradually decreased from the top to the bottom layer of the CIGS absorption layer. We also discussed the effect of Se interlayer in the CIGS absorption layer and its influence on the solar cell’s performance

  5. The RiSE climbing robot: body and leg design

    Science.gov (United States)

    Saunders, A.; Goldman, D. I.; Full, R. J.; Buehler, M.

    2006-05-01

    The RiSE robot is a biologically inspired, six legged climbing robot, designed for general mobility in scansorial (vertical walls, horizontal ledges, ground level) environments. It exhibits ground reaction forces that are similar to animal climbers and does not rely on suction, magnets or other surface-dependent specializations to achieve adhesion and shear force. We describe RiSE's body and leg design as well as its electromechanical, communications and computational infrastructure. We review design iterations that enable RiSE to climb 90° carpeted, cork covered and (a growing range of) stucco surfaces in the quasi-static regime.

  6. Colegio Nuestra Señora del Carmen-Ikastetxea

    OpenAIRE

    García Sedano, Esther

    2012-01-01

    Este trabajo se centra en la atención a la diversidad, enfocado en aquellos alumnos con necesidades educativas especiales por dificultades de aprendizaje, por trastorno de déficit de atención, dislexia, inteligencia límite (bordeline) y síndrome de triple X. Con él también se pretende la adaptación de niños de nacionalidad china a nuestros hábitos y se les ilustra en el método silábico para que aprendan el idioma del castellano con prontitud para evitar la dislexia, entre otros problemas. ...

  7. Narrativas sobre conjugalidade de mulheres que se relacionam com crossdressers

    OpenAIRE

    Vencato, Anna Paula

    2017-01-01

    Resumo: Este texto discute dados coletados em pesquisa com mulheres que se identificam como “esposas” ou “S/O’s” de homens que “praticam crossdressing”. É, também, um desdobramento de minha tese de Doutorado, sobre como homens que se identificam como crossdressers negociam esta prática em suas vidas cotidianas. A pesquisa parte de uma etnografia e é complementada por entrevistas semiestruturadas com estas mulheres. Busca-se compreender como elas lidam com as tensões relativas às convenções so...

  8. Atomic imaging of an InSe single-crystal surface with atomic force microscope

    OpenAIRE

    Uosaki, Kohei; Koinuma, Michio

    1993-01-01

    The atomic force microscope was employed to observed in air the surface atomic structure of InSe, one of III-VI compound semiconductors with layered structures. Atomic arrangements were observed in both n-type and p-type materials. The observed structures are in good agreement with those expected from bulk crystal structures. The atomic images became less clear by repeating the imaging process. Wide area imaging after the imaging of small area clearly showed that a mound was created at the sp...

  9. ¿Con humor se explica y se aprende una lengua mejor?

    Directory of Open Access Journals (Sweden)

    Ricard Morant

    2010-11-01

    Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} En el siguiente artículo nos proponemos reflexionar sobre la importancia del humor como estrategia didáctica. Para plantear si “el enseñar contento y el aprender con alegría” pueden aumentar la eficacia en el proceso de enseñanza-aprendizaje presentaremos en el primer apartado las ideas de partida, mostraremos cómo a pesar de las múltiples ventajas que puede aportar el humor a las aulas, se omite su empleo por la existencia de ciertos prejuicios y temores. Seguidamente, y a modo de ejemplo, expondremos, un tema, el tabú lingüístico, en clave de humor con el propósito de acabar planteando si el género humorístico beneficia o perjudica la práctica docente al hablar sobre una lengua o al tratar de enseñarla.

  10. Influence of CdSe layer air-baking on physical properties of CdSe-As2Se3 heterostructures

    International Nuclear Information System (INIS)

    Schauer, F.; Heza, S.; Kosek, F.; Cimpl, Z.

    1980-01-01

    An investigation is made of the influence of the air-baking time on the physical properties of a CdSe layer, which is a part of the heterogeneous structure CdSe-As 2 Se 3 used as a camera tube target. The I-U characteristics, C-U characteristics, the dependence of both the real and imaginary part admittance on frequency, and the photoconductance characteristics are measured. All measurements are carried out on heterostructures prepared with variable air-baking time of the CdSe layer: t =0, 5, 15, 40, and 120 min. The results of measurements contribute to the finding of the optimal production procedure with a minimum baking time of tsub(min) = 15 min. The heterostructures exhibit satisfactory properties. The dark current Isub(d)(U =1 V, T = 300 K) = 10 -10 Acm -2 with a rectification factor g(U = 10 V) = 10 6 and a capacitance C (2 kHz) = 2900 pFcm -2 . (author)

  11. Dipole strength in 80Se below the neutron-separation energy for the nuclear transmutation of 79Se

    Directory of Open Access Journals (Sweden)

    Makinaga Ayano

    2017-01-01

    Full Text Available The γ-ray strength function (γSF in 80Se is an important parameter to estimate the neutron-capture cross section of 79Se which is one of the long-lived fission products (LLFPs. Until now, the γSF method was applied for 80Se only above the neutron-separation energy (Sn and the evaluated 79Se(n,γ cross section has an instability caused by the GSF below Sn. We studied the dipole-strength distribution of 80Se in a photon-scattering experiment using bremsstrahlung produced by an electron beam of an energy of 11.5 MeV at the linear accelerator ELBE at HZDR. The present photoabsorption cross section of 80Se was combined with results of (γ,n experiments and are compared with predictions usinmg the TALYS code. We also estimated the 79Se(n,γ cross sections and compare them with TALYS predictionms and earlier work by other groups.

  12. Dipole strength in 80Se below the neutron-separation energy for the nuclear transmutation of 79Se

    Science.gov (United States)

    Makinaga, Ayano; Massarczyk, Ralph; Beard, Mary; Schwengner, Ronald; Otsu, Hideaki; Müller, Stefan; Röder, Marko; Schmidt, Konrad; Wagner, Andreas

    2017-09-01

    The γ-ray strength function (γSF) in 80Se is an important parameter to estimate the neutron-capture cross section of 79Se which is one of the long-lived fission products (LLFPs). Until now, the γSF method was applied for 80Se only above the neutron-separation energy (Sn) and the evaluated 79Se(n,γ) cross section has an instability caused by the GSF below Sn. We studied the dipole-strength distribution of 80Se in a photon-scattering experiment using bremsstrahlung produced by an electron beam of an energy of 11.5 MeV at the linear accelerator ELBE at HZDR. The present photoabsorption cross section of 80Se was combined with results of (γ,n) experiments and are compared with predictions usinmg the TALYS code. We also estimated the 79Se(n,γ) cross sections and compare them with TALYS predictionms and earlier work by other groups.

  13. Radiation stability of methionine-35S and selenomethionine-75Se

    International Nuclear Information System (INIS)

    Galateanu, I.; Lungu, V.V.; Viorel, D.

    1976-01-01

    The radiation stability of methionine- 35 S and selenomethionine 75 Se was investigated using the methods of thin-layer chromatography, gas chromatography and ESR. Radiation decomposition of methionine- 35 S mainly consists in an oxidation process and in the release of volatile products. The ESR-spectra of irradiated DL-methionine indicated a strong localization of the unpaired electrons on sulfur atoms. Radiation damage to selenomethionine- 75 Se as a function of radiation dose proved an increased stability of this compound and its radiation decomposition consists in the formation of oxidized products and by direct rupture of the selenium bounds accompanied by the formation of volatile compounds like CH 3 SEH and SeH 2 . The self-radiolysis of the aqueous solution of selenomethionine- 75 Se during its storage in air leads, however, to a lower decomposition rate which consists in the release of inorganic selenium and in an oxidation process. (author)

  14. Deelnemende bestuur as funksie van bestuurders se selfkonsep en mensbeskouing

    Directory of Open Access Journals (Sweden)

    W. P. Visser

    1997-06-01

    Opsomming Die literatuur toon 'n leemte aan navorsing betreffende individuele attribute wat 'n persoon tot deelnemende bestuur mag predisponeer. Met hierdie studie is ondersoek ingestel na die verband tussen twee suike attribute, naamlik selfkonsep en mensbeskouing enersyds, en gewilligheid tot deelnemende bestuur andersyds. 'n Instrument gebaseer op McGregor se teorie, is ontwikkel om mensbeskouing binne werkkonteks te meet. Met behulp van faktorontleding is twee faktore onttrek wat onderskeidelik intrinsieke en ekstrinsieke aspekte van 'n persoon se beskouing van ander se houding teenoor werk meet. 'n Gelykkansige steekproef uit 233 toesighouers van 'n openbare versorgingsonderneming het 196 bruikbare vraelyste opgelewer. 'n Beduidende verband tussen selfkonsep en mensbeskouing enersyds, en gewilligheid tot deelnemende bestuur andersyds, is met behulp van kanoniese korrelasie gevind (r =0,601; p < 0,01. Die bevinding bied steun vir McGregor se teorie dat 'n gunstige mensbeskouing tot 'n deelnemende bestuurstyl lei.

  15. Electronic Properties of Graphene-PtSe2 Contacts.

    Science.gov (United States)

    Sattar, Shahid; Schwingenschlögl, Udo

    2017-05-10

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe 2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe 2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe 2 and a p-type Schottky contact with bilayer PtSe 2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  16. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid

    2017-04-26

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  17. Preparation of PbSe nanoparticles by electron beam irradiation ...

    Indian Academy of Sciences (India)

    Wintec

    Recently, the synthesis of binary metal selenides of group. IV has been investigated ... Pb(Ac)2 and Se powder reacted ... hol (PVA), potassium hydroxide (KOH), and isopropyl. *Author for ... 40 ml distilled water and reacted adequately. Subse-.

  18. Thermal characterization of Se-Te thin films

    Czech Academy of Sciences Publication Activity Database

    Svoboda, R.; Kincl, Miloslav; Málek, J.

    2015-01-01

    Roč. 644, 25 September (2015), s. 40-46 ISSN 0925-8388 Institutional support: RVO:61389013 Keywords : krystallization kinetics * DSC * Se-Te glass Subject RIV: CA - Inorganic Chemistry Impact factor: 3.014, year: 2015

  19. ZnSe thin films by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Patil, P.S.; Tributsch, H. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CS, Glienicker Strasse-100, D-14109 Berlin (Germany); Ennaoui, A. [Hahn-Meitner-Institute, Bereich Physikalische Chemie, Abt. CG, Glienicker Strasse-100, D-14109 Berlin (Germany)

    1998-09-04

    The ZnSe thin films have been deposited onto glass substrates by the simple chemical bath deposition method using selenourea as a selenide ion source from an aqueous alkaline medium. The effect of Zn ion concentration, bath temperature and deposition time period on the quality and thickness of ZnSe films has been studied. The ZnSe films have been characterized by XRD, TEM, EDAX, TRMC (time-resolved microwave conductivity), optical absorbance and RBS techniques for their structural, compositional, electronic and optical properties. The as-deposited ZnSe films are found to be amorphous, Zn rich with optical band gap, Eg, equal to 2.9 eV

  20. Chemical bath ZnSe thin films: deposition and characterisation

    Science.gov (United States)

    Lokhande, C. D.; Patil, P. S.; Ennaoui, A.; Tributsch, H.

    1998-01-01

    The zinc selenide (ZnSe) thin films have been deposited by a simple and inexpensive chemical bath deposition (CBD) method. The selenourea was used as a selenide ion source. The ZnSe films have been characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDAX), Rutherford back scattering (RBS), and optical absorption. The as-deposited ZnSe films on various substrates are found to be amorphous and contain O2 and N2 in addition to Zn and Se. The optical band gap of the film is estimated to be 2.9 eV. The films are photoactive as evidenced by time resolved microwave conductivity (TRMC).

  1. Electronic Properties of Graphene–PtSe2 Contacts

    KAUST Repository

    Sattar, Shahid; Schwingenschlö gl, Udo

    2017-01-01

    In this article, we study the electronic properties of graphene in contact with monolayer and bilayer PtSe2 using first-principles calculations. It turns out that there is no charge transfer between the components because of the weak van der Waals interaction. We calculate the work functions of monolayer and bilayer PtSe2 and analyze the band bending at the contact with graphene. The formation of an n-type Schottky contact with monolayer PtSe2 and a p-type Schottky contact with bilayer PtSe2 is demonstrated. The Schottky barrier height is very low in the bilayer case and can be reduced to zero by 0.8% biaxial tensile strain.

  2. Optical Properties of Multilayer CdSe/POLYMER Structures

    Science.gov (United States)

    Red'Ko, V. P.; Voitenkov, A. I.; Kovalenko, O. E.

    The effects of preparation condition, concentration and size of particles upon optical and photoelectrical characteristics of multilayer structures CdSe/polyethylene terephthalate obtained by electron-beam evaporation were investigated.

  3. Processing and characterization of bulk FeSe

    Czech Academy of Sciences Publication Activity Database

    Muralidhar, M.; Hanai, T.; Furutani, K.; Diko, P.; Jirsa, Miloš; Murakami, M.

    2016-01-01

    Roč. 4, č. 3 (2016), s. 109-115 ISSN 2328-2231 Institutional support: RVO:68378271 Keywords : FeSe * x-ray diffraction * magnetization measurements * SEM * EDX analysis Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Fabrication and Photocatalytic Properties of ZnSe Nanorod Films

    Directory of Open Access Journals (Sweden)

    Jiajia Yin

    2016-01-01

    Full Text Available ZnSe nanorod films grown on fused quartz glass substrates via a simple two-step synthesis protocol were demonstrated to be environmentally safe and effective recyclable photocatalysts. These films showed greatly enhanced photocatalytic activity compared to pulsed laser deposition ZnSe films in the degradation of methyl orange dye solutions. The well-crystalized ZnSe nanorods had a length of 15 µm and a diameter of 200 nm and were densely grown on the substrate. The morphology, crystal structure, crystal phase, and photophysical properties of the ZnSe nanorod films were investigated using field-emission scanning electron microscopy (FE-SEM, UV-Vis spectroscopy, X-ray diffraction (XRD, transmission electron microscopy (TEM, and high resolution transmission electron microscopy (HRTEM.

  5. Petrus Abelardus se Megariaanse argument in Theologia 'Scholarium'

    African Journals Online (AJOL)

    Test

    7 Jun 2011 ... Martin Heidegger se beroemde opmerking (1958:37; 'Die wêreld word donker . .... Luther en die Wes-Europese Kerkhervorming}]). 7. ...... King, P., 2004, 'Peter Abelard', Stanford Encyclopedia of Philosophy, viewed February.

  6. Nematicity, magnetism and superconductivity in FeSe.

    Science.gov (United States)

    Böhmer, Anna E; Kreisel, Andreas

    2018-01-17

    Iron-based superconductors are well known for their complex interplay between structure, magnetism and superconductivity. FeSe offers a particularly fascinating example. This material has been intensely discussed because of its extended nematic phase, whose relationship with magnetism is not obvious. Superconductivity in FeSe is highly tunable, with the superconducting transition temperature, T c , ranging from 8 K in bulk single crystals at ambient pressure to almost 40 K under pressure or in intercalated systems, and to even higher temperatures in thin films. In this topical review, we present an overview of nematicity, magnetism and superconductivity, and discuss the interplay of these phases in FeSe. We focus on bulk FeSe and the effects of physical pressure and chemical substitutions as tuning parameters. The experimental results are discussed in the context of the well-studied iron-pnictide superconductors and interpretations from theoretical approaches are presented.

  7. Hjemløse borgeres sygdom og brug af sundhedsydelser

    DEFF Research Database (Denmark)

    Benjaminsen, Lars; Birkelund, Jesper Fels; Enemark, Morten Holm

    sygdom er meget udbredt blandt hjemløse borgere. Men også når man korrigerer for misbrug og psykisk sygdom, har de hjemløse borgere forøget risiko for en række sygdomme som fx infektionssygdomme, lungebetændelse og KOL. Undersøgelsen identificerer også et merforbrug af sundhedsydelser blandt de hjemløse...... tandlæge og speciallæge. Den stærke oversygelighed i gruppen af hjemløse borgere peger generelt på et behov for at medtænke en sundhedsmæssig dimension i den sociale støtte til disse borgere. Undersøgelsen er finansieret af Helsefonden....

  8. Sample (S): SE57_S08 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available SE57_S08 Lotus japonicus (accessions B129 gifu and MG20 miyakojima) Lotus japonicus... NCBI taxonomy:34305 Lotus japonicus accessions were a gift from Dr. Toshio Aoki (Nihon University, Japan). ...

  9. Enhancement of hole mobility in InSe monolayer via an InSe and black phosphorus heterostructure.

    Science.gov (United States)

    Ding, Yi-Min; Shi, Jun-Jie; Xia, Congxin; Zhang, Min; Du, Juan; Huang, Pu; Wu, Meng; Wang, Hui; Cen, Yu-Lang; Pan, Shu-Hang

    2017-10-05

    To enhance the low hole mobility (∼40 cm 2 V -1 s -1 ) of InSe monolayer, a novel two-dimensional (2D) van der Waals heterostructure made of InSe and black phosphorus (BP) monolayers with high hole mobility (∼10 3 cm 2 V -1 s -1 ) has been constructed and its structural and electronic properties are investigated using first-principles calculations. We find that the InSe/BP heterostructure exhibits a direct band gap of 1.39 eV and type-II band alignment with electrons (holes) located in the InSe (BP) layer. The band offsets of InSe and BP are 0.78 eV for the conduction band minimum and 0.86 eV for the valence band maximum, respectively. Surprisingly, the hole mobility in the InSe/BP heterostructure exceeds 10 4 cm 2 V -1 s -1 , which is one order of magnitude larger than the hole mobility of BP and three orders larger than that of the InSe monolayer. The electron mobility is also increased to 3 × 10 3 cm 2 V -1 s -1 . The physical reason has been analyzed deeply, and a universal method is proposed to improve the carrier mobility of 2D materials by forming heterostructures with them and other 2D materials with complementary properties. The InSe/BP heterostructure can thus be widely used in nanoscale InSe-based field-effect transistors, photodetectors and photovoltaic devices due to its type-II band alignment and high carrier mobility.

  10. Antiphase Boundaries in the Turbostratically Disordered Misfit Compound (BiSe)(1+δ)NbSe2.

    Science.gov (United States)

    Mitchson, Gavin; Falmbigl, Matthias; Ditto, Jeffrey; Johnson, David C

    2015-11-02

    (BiSe)(1+δ)NbSe2 ferecrystals were synthesized in order to determine whether structural modulation in BiSe layers, characterized by periodic antiphase boundaries and Bi-Bi bonding, occurs. Specular X-ray diffraction revealed the formation of the desired compound with a c-axis lattice parameter of 1.21 nm from precursors with a range of initial compositions and initial periodicities. In-plane X-ray diffraction scans could be indexed as hk0 reflections of the constituents, with a rectangular basal BiSe lattice and a trigonal basal NbSe2 lattice. Electron micrographs showed extensive turbostratic disorder in the samples and the presence of periodic antiphase boundaries (approximately 1.5 nm periodicity) in BiSe layers oriented with the [110] direction parallel to the zone axis of the microscope. This indicates that the structural modulation in the BiSe layers is not due to coherency strain resulting from commensurate in-plane lattices. Electrical transport measurements indicate that holes are the dominant charge carrying species, that there is a weak decrease in resistivity as temperature decreases, and that minimal charge transfer occurs from the BiSe to NbSe2 layers. This is consistent with the lack of charge transfer from the BiX to the TX2 layers reported in misfit layer compounds where antiphase boundaries were observed. This suggests that electronic considerations, i.e., localization of electrons in the Bi-Bi pairs at the antiphase boundaries, play a dominant role in stabilizing the structural modulation.

  11. Synthesis and properties of new CdSe-AgI-As{sub 2}Se{sub 3} chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kassem, M. [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France); Le Coq, D., E-mail: david.lecoq@univ-littoral.fr [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France); Fourmentin, M.; Hindle, F.; Bokova, M.; Cuisset, A.; Masselin, P.; Bychkov, E. [Univ Lille Nord de France, F-59000 Lille (France); ULCO, LPCA, EAC CNRS 4493 F-59140 Dunkerque (France)

    2011-02-15

    Research highlights: {yields} Determination of the glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system. {yields} Characterization of macroscopic properties of the new CdSe-AgI-As{sub 2}Se{sub 3} glasses. {yields} Far infrared transmission of chalcogenide glasses. {yields} Characterization of the total conductivity of CdSe-AgI-As{sub 2}Se{sub 3} glasses. -- Abstract: The glass-forming region in the pseudo-ternary CdSe-AgI-As{sub 2}Se{sub 3} system was determined. Measurements including differential scanning calorimetry (DSC), density, and X-ray diffraction were performed. The effect resulting from the addition of CdSe or AgI has been highlighted by examining three series of different base glasses. The characteristic temperatures of the glass samples, including glass transition (T{sub g}), crystallisation (T{sub x}), and melting (T{sub m}) temperatures are reported and used to calculate their {Delta}T = T{sub x} - T{sub g} and their Hruby, H{sub r} = (T{sub x} - T{sub g})/(T{sub m} - T{sub x}), criteria. Evolution of the total electrical conductivity {sigma} and the room temperature conductivity {sigma}{sub 298} was also studied. The terahertz transparency domain in the 50-600 cm{sup -1} region was pointed for different chalcogenide glasses (ChGs) and the potential of the THz spectroscopy was suggested to obtain structural information on ChGs.

  12. Insights into the microstructural and physical properties of colloidal Fe:ZnSe nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Ruishi, E-mail: rxie@foxmail.com [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Yuanli [Department of Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Jiang, Linhai; Zhang, Xingquan [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China)

    2014-10-30

    Highlights: • We present a facile and environmentally friendly protocol to fabricate Fe:ZnSe nanocrystals. • The microstructural and physical properties of Fe:ZnSe nanocrystals were systematically investigated. • The current synthesis is dramatically simple and highly reproducible, it will facilitate the commercial scale synthesis of highly luminescent water-soluble nanocrystals with surface functionality in the near future. - Abstract: Here, we present a facile and environmentally friendly synthetic protocol to fabricate highly luminescent and water-soluble Fe:ZnSe nanocrystals in aqueous solution at low temperature. The microstructure and various physical properties (e.g., crystal structure, interplanar spacing, lattice parameter, crystalline size, lattice microstrain, intrinsic stress, X-ray density, specific surface area, dislocation density, porosity, agglomeration number) of the Fe:ZnSe nanocrystals were systematically investigated using X-ray diffraction. The particle size and morphology of the Fe:ZnSe nanocrystals were determined by transmission electron microscopy. The optical properties (e.g., absorption and photoluminescence) of the fabricated nanocrystals were explored using ultraviolet–visible absorption and photoluminescence spectroscopies, respectively. The surface functionalization of the Fe:ZnSe nanocrystals by mercaptoacetic acid ligand was evidenced by Fourier transform infrared spectroscopy. To confirm the elementary composition of the obtained nanocrystals, Energy dispersive X-ray spectroscopy was performed. To further shed light upon elemental distribution of the resulting nanocrystals, elemental mapping measurements were conducted. Moreover, the underlying mechanisms were also elucidated. As a consequence, the current investigation not only provides a deep insight into exploring the physical properties of doped nanocrystals, but also demonstrates a useful synthetic strategy for producing water-soluble and highly fluorescent doped

  13. Annotation Method (AM): SE7_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE7_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  14. On the reversibility window in binary As-Se glasses

    Energy Technology Data Exchange (ETDEWEB)

    Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv UA-79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa PL-42201 (Poland); Faculty of Physics of Opole University of Technology, 75 Ozimska str., Opole PL-45370 (Poland); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv UA-79031 (Ukraine); Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa PL-42201 (Poland)], E-mail: shpotyuk@novas.lviv.ua; Kozdras, A. [Faculty of Physics of Opole University of Technology, 75 Ozimska str., Opole PL-45370 (Poland)

    2007-10-29

    Physical ageing effects caused by prolonged natural storage are recorded for binary As{sub x}Se{sub 1-x} glasses with 0.2{<=}x<0.4. Their origin is associated with pure 'shrinkage' of under-constrained glass networks. It is shown that only stoichiometric As{sub 2}Se{sub 3} composition, which network is formed by a so-called self-organized phase, possesses the ideal non-ageing ability.

  15. Se aprende poco : ¿Qué podemos hacer?

    OpenAIRE

    Quinquer, Dolors

    2006-01-01

    La situación en las aulas es más compleja, heterogénea y pluricultural que antes; las competencias que se han de desarrollar se han diversificado, ahora son cognitivas, éticas y sociales, mientras que los marcos organizativos siguen tan rígidos como siempre. En este contexto, comparando España con otros países, parece que los alumnos aprenden poco.¿Qué podemos hacer? 

  16. Annotation Method (AM): SE2_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE2_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  17. Annotation Method (AM): SE4_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE4_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  18. Annotation Method (AM): SE9_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE9_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  19. Annotation Method (AM): SE3_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE3_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  20. Annotation Method (AM): SE6_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE6_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  1. Annotation Method (AM): SE1_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE1_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  2. Annotation Method (AM): SE8_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE8_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  3. Annotation Method (AM): SE5_AM1 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available base search. Peaks with no hit to these databases are then selected to secondary se...arch using exactMassDB and Pep1000 databases. After the database search processes, each database hits are ma...SE5_AM1 PowerGet annotation A1 In annotation process, KEGG, KNApSAcK and LipidMAPS are used for primary data

  4. Det monstrøse i Ezekiels vision

    DEFF Research Database (Denmark)

    Nielsen, Kirsten

    2011-01-01

    Artiklen viser, hvordan det monstrøse introduceres i Ezekiels Bog kap. 1 i form af nogle sammensatte levende væsener, der har træk hentet fra både menneske- og dyreverdenen. Det monstrøse består i denne overskridelse af de gængse grænser og problematiserer dermed de velkendte klassifikationer. Og...

  5. 75Se-labelled cortisol in analysis by competition

    International Nuclear Information System (INIS)

    Glover, J.S.; Chambers, V.E.M.

    1975-01-01

    Selenium 75 has nuclear properties very suitable for the labelling of steroids used as tracers in competition analysis. A method of preparing a selenium-labelled cortisol derivative, 75 Se methylselenoprednisolone, is described. A system based on bonding competition between plasma cortisol and 75 Se methylselenoprednisolone on transcortine was studied, the separation taking place on a Sephadex adsorbant. An early analysis with highly stable reagents was achieved [fr

  6. de drogas que se consumen en su medio

    Directory of Open Access Journals (Sweden)

    José F. Enríquez Bielma

    2006-01-01

    Full Text Available Las adicciones son un problema de salud pública. Se estima que en México 3.5 millones de personas entre 12 a los 65 años han consumido algún tipo de drogas. A pesar de los avances en los estudios, se ha dejado de lado el carácter cultural que tiene la adicción. Con este estudio, se deseba conocer qué saben los estudiantes de segundo de secundaria sobre cuáles son las drogas que se consumen en su medio. Se llevó a cabo un estudio observacional con un muestreo aleatorio, con múltiples etapas y proporcional al tamaño en escuelas públicas y privadas. En total se estudiaron 42 escuelas del municipio de León, Gto., México de las cuales el 76.2% lo conformaron las escuelas públicas y el resto las escuelas privadas. Refirieron que conocen que se consumen, en su medio, 11 tipos de drogas. El 88% mencionó a la cocaína en primer lugar, en segundo lugar con un 85% la marihuana, siguiendo las tachas en un 62% y el pegamento en un 49%. En cuanto a los nombres que los estudiantes le dan a las drogas, estos van desde 23 hasta los 4 nombres, siendo la marihuana a la que se le da el mayor número de nombres, seguidos de la cocaína y el éxtasis.

  7. Synthesis and biodistribution of 75Se-dinonyl-diselenide

    International Nuclear Information System (INIS)

    Liu, Y.F.; Qian, H.Q.; Zhang, Q.X.; Wang, X.Y.; Sun, J.G.; Li, B.Z.; Zhang, W.J.

    1985-01-01

    Selenium-75-labelled dinonyl-diselenide, C 9 H 19 75 SeSeC 9 H 19 , was synthesized and identified. It was injected into white rats in order to observe the selenium distribution in the tissues using inorganic 75 SeO 2 as the control agent. The sequence order of the 75 Se-dinonyl-diselenide uptake by tissues was: pancreas, muscles, stomach, liver, kidneys, spleen, blood, lungs, heart, brain, eyes. A very high accumulation of 75 Se-dinonyl-diselenide in the pancreas was observed, similar to that of the pancreatic imaging agent 75 Se-methionine. Furthermore, the enzymatic activity of glutathione peroxidase in the case of organic diselenide injection was higher than that measured for selenite. Selenium of dinonyl-diselenide was more effective and retainable in the process of converting itself to selenium-containing enzyme via the metabolic reactions. It may be advisable to replace inorganic sodium selenite by organic selenium compounds. Sodium selenite has been widely used in the prevention of the Keshan disease in China. (author)

  8. Identification QTLs Controlling Genes for Se Uptake in Lentil Seeds.

    Directory of Open Access Journals (Sweden)

    Duygu Ates

    Full Text Available Lentil (Lens culinaris Medik. is an excellent source of protein and carbohydrates and is also rich in essential trace elements for the human diet. Selenium (Se is an essential micronutrient for human health and nutrition, providing protection against several diseases and regulating important biological systems. Dietary intake of 55 μg of Se per day is recommended for adults, with inadequate Se intake causing significant health problems. The objective of this study was to identify and map quantitative trait loci (QTL of genes controlling Se accumulation in lentil seeds using a population of 96 recombinant inbred lines (RILs developed from the cross "PI 320937" × "Eston" grown in three different environments for two years (2012 and 2013. Se concentration in seed varied between 119 and 883 μg/kg. A linkage map consisting of 1,784 markers (4 SSRs, and 1,780 SNPs was developed. The map spanned a total length of 4,060.6 cM, consisting of 7 linkage groups (LGs with an average distance of 2.3 cM between adjacent markers. Four QTL regions and 36 putative QTL markers, with LOD scores ranging from 3.00 to 4.97, distributed across two linkage groups (LG2 and LG5 were associated with seed Se concentration, explaining 6.3-16.9% of the phenotypic variation.

  9. Preparation and characterization of polycrystalline n-CdSe photoelectrode

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, T. K.

    1979-01-01

    Thin layers of polycrystalline p-CdSe were prepared by the simultaneous eletrodeposition of cadmium and selenium from cadmium sulfate and selenious acid in a sulfuric acid solution at pH 0-1 on a titanium substrate. The adherence of the layers to the substrate, stoichiometric ratio of Cd:Se and photovoltaic property of the film depend upon the molar ratio of CdSO/sub 4/ and H/sub 2/SeO/sub 3/ and current density as well as on the pH and temperature of the electrolysis bath. On increasing the current density or the ratio of CdSO/sub 4/:H/sub 2/SeO/sub 3/ in the electrolysis bath, the Cd:Se of the electrodeposit increased. The semiconductor films so prepared were annealed at 550/sup 0/C in a nitrogen atmosphere, followed by etching in an acid solution and then used to construct the photo-electrochemical cell, Ti/CdSe/Na/sub 2/S-Na/sub 2/S/sub x/(aq.)/Pt, and the current-voltage curves have been studied. 11 references.

  10. Structural manifestations of aging in Se-rich glasses

    Science.gov (United States)

    Dash, S.; Ravindren, S.; Chen, P.; Boolchand, P.

    2015-03-01

    We examine weakly cross-linked GexSe100-x (0%modulated DSC and Raman scattering experiments. Homogeneity of melts was carefully verified using FT-Raman line profiling. Upon aging at RT for 4 months, we find the width of the glass transition W(x) steadily decreasing from 10C at 7% Ge to 2C for pure Se. The 5-fold reduction of W(x) with a decrease of Ge content is accompanied by a 2-fold increase in the non-reversing enthalpy. Rejuvenation of the aged glasses changes W(x) from 15C at 7% Ge to 7C for pure Se. Tg is found to decrease upon rejuvenation with the difference (Tg(aged)-Tg(rejuv)) showing a maximum near 3% Ge and vanishing for pure Se and 6% of Ge, which are topological thresholds. These results in Se-rich glasses are consistent with aging induced decoupling of Se8 crowns and growth of extended range structural correlations between polymeric Sen chains due to lone pair interactions. At higher x, near 8-10% of Ge, eutectic effects are manifested. Work supported by NSF Grant DMR 08-53957.

  11. Agentive reflexive clitics and transitive 'se' constructions in Spanish

    Directory of Open Access Journals (Sweden)

    Grant Armstrong

    2013-11-01

    Full Text Available This paper investigates the structure of transitive sentences that contain a non-doubling reflexive clitic such as Juan se lavó todos los platos and María se leyó un libro. Though these are traditionally labelled unselected (non-core agreeing datives or aspectual datives, I argue that this label obscures a relevant difference between two classes of constructions. agentive reflexive clitic (= ARC constructions are characterized by a uniform set of effects on the external argument (= it must be an agent and the aspectual interpretation of the VP (= it must be an accomplishment. On the other hand, transitive se clitic (= TSC constructions do not impose any type of uniform restrictions on the kind of external argument they take or on the aspectual interpretation of the VP. I propose that the difference between these two constructions may be captured by treating se in the ARC construction as the realization of a special vDO head, based on an idea in Folli & Harley (2005, while se in the TSC construction is generated in the complement position of the verb and incorporates into V, forming a complex predicate, following work by De Cuyper (2006, MacDonald (2004, 2008 and MacDonald & Huidobro (2010. It is shown that many of the empirical and theoretical disagreements that plague the literature on the role of non-doubling se in transitive sentences have a simple solution given the new division established here

  12. Benefits of raising crops and animals naturally enriched with selenium in areas with selenium deficiency

    International Nuclear Information System (INIS)

    Dzhudich, I.S.

    2008-01-01

    Selenium (Se) is implicated in the protection of body tissues against oxidative stress, maintenance of defences against infection, and modulation of growth and development. The natural environment has a profound influence on its contents in the food chain and the development and distribution of Se responsive diseases. To overcome the Se deficiency problem and assure safe and adequate Se intakes, different methods were developed. Its efficiency depends on Se compounds absorption, its nutritional availability, long-term retention, convertibility of tissue Se stores into biologically active forms and the history of Se nutrition, influencing the proportion of absorbed retained, or excreted Se from diet. Since the dominant metabolically active Se forms are found in proteins as seleno analogues of sulphur amino acids, rather than selenotrisulphides and other acid labile Se compounds, we developed our own procedure for foliar enrichment of crops with Se, enabling the production of crops and animals with adequate Se content in low Se areas. By foliar application of Se salts, we optimize Se contents of many parameters important for plants quality, thus contributing to the better status of many essential, in diet often deficient nutrients. The utilization of these crops in animal nutrition, contributes to the nutritive value of animal products not only due to adequate Se content, but also higher values of other quality parameters. Consumption of such produced crops and animal products by humans in areas with low dietary Se intake has shown to have significant overall health benefits

  13. NaviSE: superenhancer navigator integrating epigenomics signal algebra.

    Science.gov (United States)

    Ascensión, Alex M; Arrospide-Elgarresta, Mikel; Izeta, Ander; Araúzo-Bravo, Marcos J

    2017-06-06

    Superenhancers are crucial structural genomic elements determining cell fate, and they are also involved in the determination of several diseases, such as cancer or neurodegeneration. Although there are pipelines which use independent pieces of software to predict the presence of superenhancers from genome-wide chromatin marks or DNA-interaction protein binding sites, there is not yet an integrated software tool that processes automatically algebra combinations of raw data sequencing into a comprehensive final annotated report of predicted superenhancers. We have developed NaviSE, a user-friendly streamlined tool which performs a fully-automated parallel processing of genome-wide epigenomics data from sequencing files into a final report, built with a comprehensive set of annotated files that are navigated through a graphic user interface dynamically generated by NaviSE. NaviSE also implements an 'epigenomics signal algebra' that allows the combination of multiple activation and repression epigenomics signals. NaviSE provides an interactive chromosomal landscaping of the locations of superenhancers, which can be navigated to obtain annotated information about superenhancer signal profile, associated genes, gene ontology enrichment analysis, motifs of transcription factor binding sites enriched in superenhancers, graphs of the metrics evaluating the superenhancers quality, protein-protein interaction networks and enriched metabolic pathways among other features. We have parallelised the most time-consuming tasks achieving a reduction up to 30% for a 15 CPUs machine. We have optimized the default parameters of NaviSE to facilitate its use. NaviSE allows different entry levels of data processing, from sra-fastq files to bed files; and unifies the processing of multiple replicates. NaviSE outperforms the more time-consuming processes required in a non-integrated pipeline. Alongside its high performance, NaviSE is able to provide biological insights, predicting cell

  14. Achieving tunable doping of MoSe2 based devices using GO@MoSe2 heterostructure

    Science.gov (United States)

    Maji, Tuhin Kumar; Tiwary, Krishna Kanhaiya; Karmakar, Debjani

    2017-05-01

    Doping nature of MoSe2, one of the promising Graphene analogous device material, can be tuned by controlling the concentration of functional groups in Graphene oxide (GO)@MoSe2 heterostructure. In this study, by first-principles simulation, we have observed that GO can be used as a carrier injection layer for MoSe2, where n or p type carriers are introduced within MoSe2 layer depending on the type and concentration of functional moieties in it. Both n and p-type Schottky barrier height modulations are investigated for different modeled configurations of the heterostructure. This combinatorial heterostructure can be a promising material for future electronic device application.

  15. Hydrogeochemical evaluation. Preliminary site description Forsmark area - version 1.2

    International Nuclear Information System (INIS)

    Laaksoharju, Marcus

    2005-03-01

    Siting studies for SKB's programme of deep geological disposal of nuclear fuel waste currently involves the investigation of two locations, Forsmark and Laxemar-Simpevarp, on the eastern coast of Sweden to determine their geological, hydrogeochemical and hydrogeological characteristics. Present work completed has resulted in Model version 1.2 which represents the second evaluation of the available Forsmark groundwater analytical data collected up to June, 2004. The Hydrochemical Analytical Group (HAG) had access to data where a total of 1,131 water samples had been collected from the surface and sub-surface environment; 252 samples were collected from drilled boreholes. The deepest fracture groundwater samples with sufficient analytical data reflected depths down to 1 km. Most of the waters sampled (66%) lacked crucial analytical information that restricted the evaluation. Model version 1.2 focuses on geochemical and mixing processes affecting the groundwater composition in the uppermost part of the bedrock, down to repository levels, and eventually extending to 1,000 m depth. The complex groundwater evolution and patterns at Forsmark are a result of many factors such as: a) the present-day topography and proximity to the Baltic Sea, b) past changes in hydrogeology related to glaciation/deglaciation, land uplift and repeated marine/lake water regressions/ transgressions, and c) organic or inorganic alteration of the groundwater composition caused by microbial processes or water/rock interactions. The sampled groundwaters reflect to various degrees processes relating to modern or ancient water/rock interactions and mixing. The groundwater flow regimes at Forsmark are considered local and extend down to depths of around 600 m depending on hydraulic conditions. Close to the Baltic Sea coastline where topographical variation is even less, groundwater flow penetration to depth will subsequently be less marked and such areas will tend to be characterised by groundwater

  16. Hydrogeochemical evaluation. Preliminary site description Forsmark area - version 1.2

    Energy Technology Data Exchange (ETDEWEB)

    Laaksoharju, Marcus (ed.) [Geopoint AB, Stockholm (Sweden)

    2005-03-15

    Siting studies for SKB's programme of deep geological disposal of nuclear fuel waste currently involves the investigation of two locations, Forsmark and Laxemar-Simpevarp, on the eastern coast of Sweden to determine their geological, hydrogeochemical and hydrogeological characteristics. Present work completed has resulted in Model version 1.2 which represents the second evaluation of the available Forsmark groundwater analytical data collected up to June, 2004. The Hydrochemical Analytical Group (HAG) had access to data where a total of 1,131 water samples had been collected from the surface and sub-surface environment; 252 samples were collected from drilled boreholes. The deepest fracture groundwater samples with sufficient analytical data reflected depths down to 1 km. Most of the waters sampled (66%) lacked crucial analytical information that restricted the evaluation. Model version 1.2 focuses on geochemical and mixing processes affecting the groundwater composition in the uppermost part of the bedrock, down to repository levels, and eventually extending to 1,000 m depth. The complex groundwater evolution and patterns at Forsmark are a result of many factors such as: a) the present-day topography and proximity to the Baltic Sea, b) past changes in hydrogeology related to glaciation/deglaciation, land uplift and repeated marine/lake water regressions/ transgressions, and c) organic or inorganic alteration of the groundwater composition caused by microbial processes or water/rock interactions. The sampled groundwaters reflect to various degrees processes relating to modern or ancient water/rock interactions and mixing. The groundwater flow regimes at Forsmark are considered local and extend down to depths of around 600 m depending on hydraulic conditions. Close to the Baltic Sea coastline where topographical variation is even less, groundwater flow penetration to depth will subsequently be less marked and such areas will tend to be characterised by

  17. Optical characterization of CdSe/ZnTe type-II interfaces for photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Richters, Jan-Peter; Bleuse, Joel [CEA-CNRS group ' ' Nanophysique et semiconducteurs' ' , CEA-Grenoble, INAC, SP2M, 17 rue des Martyrs, 38042 Grenoble (France); Gerard, Lionel; Andre, Regis [CEA-CNRS group ' ' Nanophysique et semiconducteurs' ' , Institut Neel, CNRS, BP 166, 38042 Grenoble Cedex 9 (France)

    2012-07-01

    Solar cells based on direct bandgap semiconductors (GaAs,CdTe,CdSe..) show an efficient light absorption compared to silicon solar cells. This is an advantage for material savings due to thinner absorbers, but it also comes with the drawback of higher losses due to efficient radiative electron-hole recombination. Such losses could be prevented through the use of type-II interfaces which separate electrons and holes within the active area, similar to a p-n junction. We report a study of CdSe/ZnTe samples showing such an interface. The CdSe bandgap (1.7 eV) is well adapted to the solar spectrum and its lattice parameter mismatch with ZnTe is exceptionally low. We have grown, by MBE, different kinds of samples like CdSe/ZnTe 2D interfaces and superlattices and present time-resolved spectroscopy results which specify the efficiency of the electron-hole separation in these type-II structures. The measured decay time can be above 100 ns for the interface optical transition, i.e. 3 orders of magnitude slower than the typical PL decay time for the constitutive materials taken separately.

  18. High resistivity ZnSe coated substrates for microstrip gas chambers

    International Nuclear Information System (INIS)

    Sudharsanan, R.; Greenwald, A.C.; Vakerlis, G.; Yoganathan, M.; Cho, H.S.; Kadyk, J.; Dubeau, J.; Dixit, M.

    1998-01-01

    Microstrip gas chambers (MSGCs) require substrates with sheet resistance in the range of 10 13 --10 16 ohms/square to eliminate polarization and surface charging effects between the electrodes. Thin films of II-VI semiconductors deposited on glass or plastic substrates are attractive for this application since bulk resistivity of these semiconductors vary in the range 10 9 --10 12 ohm-cm and films with good uniformity can be deposited over large-areas using inexpensive deposition techniques. In this paper, deposition, characterization, and fabrication of MSGCs using ZnSe thin films are reported for the first time. ZnSe thin films were deposited on glass and plastic substrates by thermal evaporation. Sheet resistance of ZnSe varied in the range of 10 15 to 10 16 ohms/square depending on the deposition conditions. A MSGC detector fabricated using a 0.5 microm thick ZnSe layer on glass substrate exhibited best values; gas gain of 25,000 and an energy resolution of about 16.7% FWHM at a gain of 1,080 for a 55 Fe source

  19. Open hydrological data at hypeweb.smhi.se

    Science.gov (United States)

    Arheimer, Berit; Strömbäck, Lena; Andersson, Jafet; Donnelly, Chantal; Gustafsson, David; Pechlivianidis, Ilias; Strömqvist, Johan

    2016-04-01

    Following the EU open data strategy the Swedish Meteorological and Hydrological Institute (SMHI) is providing large parts of the databases openly available. These data are ranging from historical observations to climate predictions in various areas such as weather, oceanography and hydrology. For the Water Service called Hypeweb (www.hypeweb.smhi.se), we provide data for water management. So far, the data has been used in: (i) Climate change impact assessments on water resources and dynamics; (ii) The European Water Framework Directive (WFD) for characterization and development of measure programs to improve the ecological status of water bodies; (iii) Design variables for infrastructure constructions; (iv) Spatial water-resource mapping; (v) Operational forecasts (1-10 days and seasonal) on floods and droughts; (vi) Input to oceanographic models for operational forecasts and marine status assessments; and (vii) Research. The data of Hypeweb is based on other open data sources that has been merged and re-purposed by using the Hydrological Predictions for the Environment (HYPE) model in world-wide applications with high resolution. HYPE is a dynamic, semi-distributed, process-based, and integrated catchment model. So far, the following regional domains have been modelled with different resolutions (number of subbasins within brackets): Sweden (37 000), Europe (35 000), Arctic basin (30 000), La Plata River (6 000), Niger River (800), Middle-East North-Africa (31 000), and the Indian subcontinent (6 000). The web site provides several interactive applications for exploring results from the models. The user can explore an overview of various water variables for historical and future conditions. Moreover the user can explore and download historical time series of discharge for each basin and explore the performance of the model towards observed river flow. The presentation will give an overview of the functionality of the web site and the available hydrological

  20. Liquidus Projection and Isothermal Section of the Sb-Se-Sn System

    Science.gov (United States)

    Chang, Jui-shen; Chen, Sinn-wen

    2017-12-01

    Sb-Se-Sn ternary alloys are promising chalcogenide materials. The liquidus projection and 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system are determined. Numerous Sb-Se-Sn alloys are prepared, and their primary solidification phases are examined. In addition to the three terminal phases, (Sb), (Se) and (Sn), there are Sb2Sn3, SbSn, SnSe, SnSe2, Sb2Se3, Sn2Sb9Se9, and SnSb2Se4 phases. In addition, there are two miscibility gaps along the Sb-Se and Se-Sn and sides. There are ten invariant reactions in the Sb-Se-Sn ternary system, and seven of them are experimentally determined in this study. The lowest reaction temperature of determined invariant reaction is L + SbSn = (Sn) + SnSe at 515.4 K ± 5 K (242.2 °C ± 5 °C). There are nine tie-triangles, which are Liquid + SbSn + SnSe, SbSn + SnSe + (Sb), SnSe + (Sb) + Sn2Sb9Se9, (Sb) + Sb2Se3 + Sn2Sb9Se9, SnSe + Sn2Sb9Se9 + SnSb2Se4, Sb2Se3 + Sn2Sb9Se9 + SnSb2Se4, SnSe + SnSe2 + SnSb2Se4, SnSe2 + SnSb2Se4 + Sb2Se3, and SnSe2 + Sb2Se3 + Liquid in the 673.2 K (400 °C) isothermal section of the Sb-Se-Sn ternary system.

  1. Banks offer SE more than it asked for

    International Nuclear Information System (INIS)

    Janoska, J.

    2004-01-01

    About a year ago, when new management took over the financial department of Slovenske elektrarne (SE), a.s. the company was in crisis. It faced an acute cash-flow deficit and due loans of over 20 bill. Sk (501.21 mil. Eur). SE could not provide adequate guarantees for the required loans and without state guarantees it was virtually impossible or too expensive to obtain additional loans. But last week the situation changed for the better. Despite the fact that due to the restructuring of SE's loan portfolio, the company will pay the banks 3 bill. Sk (75.18 mil. Eur) less interest over the next three years than under the original arrangements, even the bakers seemed satisfied. A loan portfolio full of non-standard agreements signed with about 30 banks had previously prevented decisions regarding the structure of the company's assets and liabilities.The cabinet refused to admit that SE was in crisis and offered SE for sale, although it could not be privatised due to its debt structure and the fact that it was close to default. Despite this unfavourable situation, company economists decided to make an offensive move -in cooperation with a small group of banks they converted the tens of company loan agreements into a new loan package that will be simpler, cheaper, and with longer maturity periods, which will not require state guarantees. SE managed to restructure debts with a total value of 550 mil. Eur and until these transactions are completed the banks offered SE a bridge loan of 110 mil. Eur. The transaction related to a syndicated loan of 350 mil. Eur which was concluded in April. Eurobonds with a total value of 200 mil. Eur were issued two months later. The banks offered the company more than it requested. Demand for the Eurobond issue exceeded the 200 mil. Eur of bonds on offer. (author)

  2. Distopie voor oë: Eben Venter se duister kuns

    Directory of Open Access Journals (Sweden)

    Harry Sewlall

    2016-08-01

    Full Text Available Sedert die verskyning van Joseph Conrad se novelle, Heart of Darkness, uitgegee as vervolgverhaal in 1899, was daar al verskeie pogings om Conrad se teks te ‘herskryf’, al was die verwantskap met die meesterteks dikwels gering of selfs twyfelagtig. Nog ’n herskrywing van Conrad se teks is Eben Venter se roman Trencherman, aanvanklik in Afrikaans uitgegee as Horrelpoot. Hierdie teks volg die meesterteks baie nougeset na, nie slegs deur aanhalings daaruit as motto’s vooraan elke hoofstuk te gebruik nie, maar ook deur beelde en woorde uit die oorspronklike teks op ooglopende of bedekte wyse in die narratief in te weef. Die vrae waarmee ’n leser soos ek, wat nie vertroud is met Afrikaans nie, gekonfronteer word, is of dit ’n geval van plagiaat is of ’n oefening in intertekstualiteit en ofdie boek eerder ’n poging is om sensasie te wek ten einde meer boeke te verkoop. Hierdie vraevorm die basis vir ’n intertekstuele verkenning van die twee tekste, wat neerkom op ’n stiplees van Conrad se teks langs Trencherman ten einde die intertekstuele skakels tussen die twee tekste te identifiseer. Teoreties is die artikel gebaseer op die werk van Kristeva en Barthes. Die ondersoek het bevestig dat Trencherman inderdaad ’n oefening in intertekstualiteit is, nie slegs as intertekstualiteit nie, maar eerder as ’n in-gesprek-tree met Conrad se meesterteks. Daaruit volg die slotsom dat Trencherman ’n geldige intertekstuele antwoord is op Heart of darkness wat Conrad se beroemde novelle dekonstrueer en die draaiboek daarvan transponeer na ’n distopiese, post-demokratiese Suid-Afrika.

  3. Formation of a Colloidal CdSe and ZnSe Quantum Dots via a Gamma Radiolytic Technique

    Directory of Open Access Journals (Sweden)

    Aeshah Salem

    2016-09-01

    Full Text Available Colloidal cadmium selenide (CdSe and zinc selenide (ZnSe quantum dots with a hexagonal structure were synthesized by irradiating an aqueous solution containing metal precursors, poly (vinyl pyrrolidone, isopropyl alcohol, and organic solvents with 1.25-MeV gamma rays at a dose of 120 kGy. The radiolytic processes occurring in water result in the nucleation of particles, which leads to the growth of the quantum dots. The physical properties of the CdSe and ZnSe nanoparticles were measured by various characterization techniques. X-ray diffraction (XRD was used to confirm the nanocrystalline structure, energy-dispersive X-ray spectroscopy (EDX was used to estimate the material composition of the samples, transmission electron microscopy (TEM was used to determine the morphologies and average particle size distribution, and UV-visible spectroscopy was used to measure the optical absorption spectra, from which the band gap of the CdSe and ZnSe nanoparticles could be deduced.

  4. ¿Qué se hace para no morir de hambre? Dinámicas domésticas y alimentación en la niñez en un área rural de extrema pobreza de México What to do to avoid death by starvation? Domestic dynamics and childhood feeding practices in a rural area of extreme poverty in Mexico

    Directory of Open Access Journals (Sweden)

    Blanca Pelcastre-Villafuerte

    2006-12-01

    Full Text Available OBJETIVO: Caracterizar y comparar, en términos de estructura, creencias y comportamiento en torno a la alimentación, la dinámica doméstica de hogares de niños y niñas menores de cinco años con y sin desnutrición. MATERIAL Y MÉTODOS: Estudio cualitativo con un diseño etnográfico basado en observación participante y entrevistas a profundidad a responsables del cuidado de menores e informantes clave bajo consentimiento informado verbal. El foco de observación fue el conjunto de prácticas relacionadas con el cuidado de los menores, con énfasis en las relacionadas con su alimentación, tanto al interior de los hogares como en la comunidad. Se realizaron dos estancias de campo, durante 2001, en tres comunidades rurales del Río Balsas, en el estado de Guerrero, México. RESULTADOS: Estructuras monoparentales, en etapa temprana del ciclo doméstico, generan condiciones que pueden propiciar la presencia de desnutrición de menores de cinco años. Las familias extensas representan, por su propia estructura, dinámicas domésticas más favorables. CONCLUSIONES: El problema de la desnutrición en ambientes de extrema pobreza resulta decisivamente influido por las estrategias nutricionales y las dinámicas sociales generadas en el interior de las familias.OBJECTIVE: To describe and compare household dynamics in terms of structure, beliefs and nutrition-related behavior in the homes of malnourished and well-nourished children less than five years of age. MATERIAL AND METHODS: The authors carried out a qualitative ethnographic study using participant observation, and in depth interviews. Interviews were conducted with the child's caretaker or key informants, prior oral informed consent. Child care and childhood feeding practices at home and in the community were the focus of observations. The study included two periods of field work conducted in 2001, in three rural municipalities from the Río Balsas region, in Guerrero state, Mexico. The

  5. After four months new privatisation committee in SE

    International Nuclear Information System (INIS)

    Janoska, J.

    2003-01-01

    In spite of a delay the Minister of Economy of the Slovak Republic wants to meet the schedule set by Government. In middle of September 2002 six prospect submitted their tender offers for entering Slovenske elektrarne (SE), a.s, Bratislava. Representative of privatisation advisor of SE, PricewaterhouseCoopers, Peter Mitka told TREND that he was in contact with the investors but they were waiting for a signal from official authorities about the current state of the tender. And they have been waiting for four months. Only last week a new privatisation commission started dealing with the offers. In spite of these facts Minister of Economy, Robert Nemcsics does not consider the process slow and said that the Ministry would use all its efforts to adhere to the original privatisation schedule prepared by the former government. He further added that everything would depend on the offers submitted. Investors are not interest in SE as a whole but only in its parts. Several members of the committee do not agree with the privatisation and restructuring principles set by the government including a split of SE to conventional and nuclear parts. One of the opponents is the former manager of SE Tibor Mikus (HZDS) - representative of the Parliament or Vladimir Mojs representative of Slovak Energeticists Unions. This put a brake on the tender and changes in the management of SE as well. Privatisation Agency FNM still has not decided upon calling a Extraordinary General Meeting of SE that would elect new bodies. Spokeswoman of FNM, Tatjana Lesajova claims that the Fund is still missing a legal analysis that would review the possibility of changing SE's Articles of Association so that the Board of Directors could be assigned based on a tender (proposal of the Ministry). Members of SE Privatisation Committee: Eva Simkova - Secretary of State, Ministry of Economy SR; Laszlo Pomothy - Secretary of State, Ministry of Economy SR; Henrich Herceg - Advisor to the Minister of Economy SR

  6. Gene expression of endoplasmic reticulum resident selenoproteins correlates with apoptosis in various muscles of se-deficient chicks.

    Science.gov (United States)

    Yao, Hai-Dong; Wu, Qiong; Zhang, Zi-Wei; Zhang, Jiu-Li; Li, Shu; Huang, Jia-Qiang; Ren, Fa-Zheng; Xu, Shi-Wen; Wang, Xiao-Long; Lei, Xin Gen

    2013-05-01

    Dietary selenium (Se) deficiency causes muscular dystrophy in various species, but the molecular mechanism remains unclear. Our objectives were to investigate: 1) if dietary Se deficiency induced different amounts of oxidative stress, lipid peroxidation, and cell apoptosis in 3 skeletal muscles; and 2) if the distribution and expression of 4 endoplasmic reticulum (ER) resident selenoprotein genes (Sepn1, Selk, Sels, and Selt) were related to oxidative damages in these muscles. Two groups of day-old layer chicks (n = 60/group) were fed a corn-soy basal diet (33 μg Se/kg; produced in the Se-deficient area of Heilongjiang, China) or the diet supplemented with Se (as sodium selenite) at 0.15 mg/kg for 55 d. Dietary Se deficiency resulted in accelerated (P muscles. All these responses were stronger in the pectoral muscle than in the thigh and wing muscles (P muscles. Expression of Sepn1, Sels, and Selt in these muscles was correlated with (r > 0.72; P muscle demonstrated unique expression patterns of the ER resident selenoprotein genes and GPx activity, along with elevated susceptibility to oxidative cell death, compared with the other skeletal muscles. These features might help explain why it is a primary target of Se deficiency diseases in chicks.

  7. ¿Y, cómo se hacen?

    Directory of Open Access Journals (Sweden)

    Juan Ruiz

    2015-01-01

    Full Text Available El mundo de los dibujos animados es producto de la imaginación, de la fantasía que vuela en los sueños de los hombres de cualquier edad. El artículo relata la forma en cómo estos simpáticos personajes, que vemos a diario en el cine o la televisión, pueden moverse tan libremente y con tanto desenfado. Se parte de la idea o argumento, el guionista narra la historia de lo que será el animado. Luego el director con un dibujante trazan las escenas principales de la historia (storyboard o guión dibujado se discute con los artistas y realizadores del filme; una vez aprobado este se perfila el diseño de los personajes, se realiza la escenografía (maquetas de ser necesario. Se hacen los parlamentos o diálogos de los personajes para que actores(as pongan las voces y sigue el proceso más fino y técnico.

  8. Transition probabilities in neutron-rich Se,8684

    Science.gov (United States)

    Litzinger, J.; Blazhev, A.; Dewald, A.; Didierjean, F.; Duchêne, G.; Fransen, C.; Lozeva, R.; Sieja, K.; Verney, D.; de Angelis, G.; Bazzacco, D.; Birkenbach, B.; Bottoni, S.; Bracco, A.; Braunroth, T.; Cederwall, B.; Corradi, L.; Crespi, F. C. L.; Désesquelles, P.; Eberth, J.; Ellinger, E.; Farnea, E.; Fioretto, E.; Gernhäuser, R.; Goasduff, A.; Görgen, A.; Gottardo, A.; Grebosz, J.; Hackstein, M.; Hess, H.; Ibrahim, F.; Jolie, J.; Jungclaus, A.; Kolos, K.; Korten, W.; Leoni, S.; Lunardi, S.; Maj, A.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatovic, T.; Million, B.; Möller, O.; Modamio, V.; Montagnoli, G.; Montanari, D.; Morales, A. I.; Napoli, D. R.; Niikura, M.; Pollarolo, G.; Pullia, A.; Quintana, B.; Recchia, F.; Reiter, P.; Rosso, D.; Sahin, E.; Salsac, M. D.; Scarlassara, F.; Söderström, P.-A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Theisen, Ch.; Valiente Dobón, J. J.; Vandone, V.; Vogt, A.

    2015-12-01

    Reduced quadrupole transition probabilities for low-lying transitions in neutron-rich Se,8684 are investigated with a recoil distance Doppler shift (RDDS) experiment. The experiment was performed at the Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali di Legnaro using the Cologne Plunger device for the RDDS technique and the AGATA Demonstrator array for the γ -ray detection coupled to the PRISMA magnetic spectrometer for an event-by-event particle identification. In 86Se the level lifetime of the yrast 21+ state and an upper limit for the lifetime of the 41+ state are determined for the first time. The results of 86Se are in agreement with previously reported predictions of large-scale shell-model calculations using Ni78-I and Ni78-II effective interactions. In addition, intrinsic shape parameters of lowest yrast states in 86Se are calculated. In semimagic 84Se level lifetimes of the yrast 41+ and 61+ states are determined for the first time. Large-scale shell-model calculations using effective interactions Ni78-II, JUN45, jj4b, and jj4pna are performed. The calculations describe B (E 2 ;21+→01+) and B (E 2 ;61+→41+) fairly well and point out problems in reproducing the experimental B (E 2 ;41+→21+) .

  9. Electroluminescence of colloidal ZnSe quantum dots

    International Nuclear Information System (INIS)

    Dey, S.C.; Nath, S.S.

    2011-01-01

    The article reports a green chemical synthesis of colloidal ZnSe quantum dots at a moderate temperature. The prepared colloid sample is characterised by UV-vis absorption spectroscopy and transmission electron microscopy. UV-vis spectroscopy reveals as-expected blue-shift with strong absorption edge at 400 nm and micrographs show a non-uniform size distribution of ZnSe quantum dots in the range 1-4 nm. Further, photoluminescence and electroluminescence spectroscopies are carried out to study optical emission. Each of the spectroscopies reveals two emission peaks, indicating band-to-band transition and defect related transition. From the luminescence studies, it can be inferred that the recombination of electrons and holes resulting from interband transition causes violet emission and the recombination of a photon generated hole with a charged state of Zn-vacancy gives blue emission. Meanwhile electroluminescence study suggests the application of ZnSe quantum dots as an efficient light emitting device with the advantage of colour tuning (violet-blue-violet). - Highlights: → Synthesis of ZnSe quantum dots by a green chemical route. → Characterisation: UV-vis absorption spectroscopy and transmission electron microscopy. → Analysis of UV-vis absorption spectrum and transmission electron micrographs. → Study of electro-optical properties by photoluminescence and electroluminescence. → Conclusion: ZnSe quantum dots can be used as LED with dual colour emission.

  10. Optical studies of CdSe/PVA nanocomposite films

    Science.gov (United States)

    Kushwaha, Kamal Kumar; Ramrakhaini, Meera

    2018-05-01

    The nanocomposite films of CdSe nanocrystals in polyvinyl alcohol (PVA) matrix were synthesized by environmental friendly chemical method. These composites were characterized by X-ray diffraction which indicates the hexagonal crystalline structure of CdSe with crystal size up to a few nm. The crystal size is found to decrease by increasing PVA Concentration. The photoluminescence (PL) characteristics of these composite films with varying concentration of PVA as well as Cd2+ content have been investigated. The PL peak of CdSe was observed at 510 nm and higher intensity is observed by increasing PVA concentration without any change in position of PL peak. Due to proper passivation of surface states non-radiative transition are reduced which enhance the PL intensity. By increasing concentration of Cd2+ content in the CdSe/PVA nanocomposite films, smaller CdSe nanocrystals were obtained giving higher intensity and blue shift in the PL peak due to enhanced oscillator strength and quantum confinement effect. The PL peak in green and blue region makes these composite films promising materials for optical display devices. The Refractive index of these composites was also measured at sodium line with the help of Abee's refractometer and was found in the range of 2.20-2.45. It is seen that refractive index varies with polymer concentration. This may be useful for their potential application in anti-reflection coating, display devices and optical sensors.

  11. Diffusion behavior for Se and Zr in sodium-bentonite

    International Nuclear Information System (INIS)

    Sato, Haruo; Yui, Mikazu; Yoshikawa, Hideki

    1995-01-01

    Apparent diffusion coefficients for Se and Zr in bentonite were measured by in-diffusion method at room temperature using water-saturated sodium-bentonite, Kunigel V1 reg-sign containing 50wt% Na-smectite as a major mineral was used as the bentonite material. The experiments were carried out in the dry density range of 400--1,800 kg/m 3 . Bentonite samples were immersed with distilled water and saturated before the experiments. The experiments for Se were carried out under N 2 atmospheric condition (O 2 : 2.5ppm). Those for Zr were carried out under aerobic condition. The apparent diffusion coefficients decrease with increasing density of the bentonite. Since dominant species of Se in the pore water is predicted to be SeO 3 2- , Se may be retarded by anion-exclusion because of negative charge on the surface of the bentonite and little sorption. The dominant species of Zr in the porewater is predicted to be Zr(OH) 5 - or HZrO 3 - . Distribution coefficient measured for Zr on the bentonite was about 1.0 m 3 /kg from batch experiments. Therefore, the retardation may be caused by combination of the sorption and the anion-exclusion. A modeling for the diffusion mechanisms in the bentonite were discussed based on an electric double layer theory. Comparison between the apparent diffusion coefficients predicted by the model and the measured ones shows a good agreement

  12. Study of de-aggregation of mechanochemically synthesized ZnSe nanoparticles by re-milling in the presence of ZnCl2 solution

    Directory of Open Access Journals (Sweden)

    Marcela Achimovičová

    2013-12-01

    Full Text Available Conventional mechanochemical synthesis of zinc selenide, ZnSe nanoparticles was performed in a planetary ball mill by high-energy milling of zinc (Zn and selenium (Se powders. Mechanochemically synthesized ZnSe was subsequently re-milled in circulation mill in ZnCl2 solution in order to study de-aggregation, physical-chemical and optical properties of ZnSe nanoparticles. The mechanochemically synthesized and re-milled samples were characterized by X-ray diffraction analysis (XRD that confirmed the presence of cubic and hexagonal ZnSe phases. Size of crystallites calculated from XRD patterns has decreased from 50 to 19 nm for cubic ZnSe phase and from 145 to 2.5 nm for hexagonal ZnSe phase after re-milling for 110 min in ZnCl2 solution. Size, phase composition, morphology, and crystallinity of ZnSe nanoparticles were studied by transmission electron microscopy (TEM and selected area electron diffraction (SAED. UV-Vis optical spectroscopy has provided an evidence of blue shift of the re-milled nanocrystalline ZnSe particles from the direct band gap of 2.67 eV characteristic of bulk ZnSe crystals. Colloidal stability of ZnSe nanoparticles dispersions was studied by ? �potential measurements.

  13. Quasi-two-dimensional thermoelectricity in SnSe

    Science.gov (United States)

    Tayari, V.; Senkovskiy, B. V.; Rybkovskiy, D.; Ehlen, N.; Fedorov, A.; Chen, C.-Y.; Avila, J.; Asensio, M.; Perucchi, A.; di Pietro, P.; Yashina, L.; Fakih, I.; Hemsworth, N.; Petrescu, M.; Gervais, G.; Grüneis, A.; Szkopek, T.

    2018-01-01

    Stannous selenide is a layered semiconductor that is a polar analog of black phosphorus and of great interest as a thermoelectric material. Unusually, hole doped SnSe supports a large Seebeck coefficient at high conductivity, which has not been explained to date. Angle-resolved photoemission spectroscopy, optical reflection spectroscopy, and magnetotransport measurements reveal a multiple-valley valence-band structure and a quasi-two-dimensional dispersion, realizing a Hicks-Dresselhaus thermoelectric contributing to the high Seebeck coefficient at high carrier density. We further demonstrate that the hole accumulation layer in exfoliated SnSe transistors exhibits a field effect mobility of up to 250 cm2/V s at T =1.3 K . SnSe is thus found to be a high-quality quasi-two-dimensional semiconductor ideal for thermoelectric applications.

  14. Self-Assembled PbSe Nanowire:Perovskite Hybrids

    KAUST Repository

    Yang, Zhenyu

    2015-12-02

    © 2015 American Chemical Society. Inorganic semiconductor nanowires are of interest in nano- and microscale photonic and electronic applications. Here we report the formation of PbSe nanowires based on directional quantum dot alignment and fusion regulated by hybrid organic-inorganic perovskite surface ligands. All material synthesis is carried out at mild temperatures. Passivation of PbSe quantum dots was achieved via a new perovskite ligand exchange. Subsequent in situ ammonium/amine substitution by butylamine enables quantum dots to be capped by butylammonium lead iodide, and this further drives the formation of a PbSe nanowire superlattice in a two-dimensional (2D) perovskite matrix. The average spacing between two adjacent nanowires agrees well with the thickness of single atomic layer of 2D perovskite, consistent with the formation of a new self-assembled semiconductor nanowire:perovskite heterocrystal hybrid.

  15. Some kinetic properties of DySnSe2 combination

    International Nuclear Information System (INIS)

    Murguzov, M.I.; Mammadova, E.R.

    2008-01-01

    Recently, to the acquisition of multi-component alloys and combination in the presence of rare-earth metals (REM) interest has grown considerably. According to preliminary data, in the presence of rare-earth metals you can obtain perspective semiconductor materials which are of practical importance, and can be used in various fields of microelectronics in a complex system of chalcogenides. DySnSe 2 combination is also includes to this system. Physical peculiarities of these combinations have been studied in wide interval. DySnSe 2 combination crystallizes in ortho rhombic crystal system and is an indemnification n-type semiconductor material. The mechanism of electrical conductivity in DySnSe 2 semiconductor combination is complicated and cargo carrier scattering changes at low temperatures. That is why, the mixed type conductivity occurs

  16. Concentrations of Se, Ba, Zn and Mn in Brazil nuts

    Energy Technology Data Exchange (ETDEWEB)

    Armelin, Maria José A.; Maihara, Vera A.; Cardoso, Paulo S.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cozollino, Silvia M.F., E-mail: marmelin@ipen.br, E-mail: vmaihara@ipen.br, E-mail: msaiki@ipen.br, E-mail: pscsilva@ipen.br, E-mail: smfcozzo@usp.br [Universidade de São Paulo (USP), SP (Brazil). Faculdade de Ciências Farmacêuticas

    2017-07-01

    The concentrations of Se, Ba, Zn and Mn were determined in samples of Brazil nuts collected in two ways: a) in a production farm predominantly for export and, b) in various points of sale from different regions of Brazil. Instrumental neutron activation analysis was the analytical technique used in this study. Results indicate that the concentrations of Se and Ba varied greatly among the Brazil nut samples analyzed. This large variability may be related to the soil characteristics from which the nuts were produced. An inverse correlation was observed between the concentrations of Se and Ba. On the other hand, the concentrations of Zn and Mn did not show significant differences among these samples. (author)

  17. PySE: Python Source Extractor for radio astronomical images

    Science.gov (United States)

    Spreeuw, Hanno; Swinbank, John; Molenaar, Gijs; Staley, Tim; Rol, Evert; Sanders, John; Scheers, Bart; Kuiack, Mark

    2018-05-01

    PySE finds and measures sources in radio telescope images. It is run with several options, such as the detection threshold (a multiple of the local noise), grid size, and the forced clean beam fit, followed by a list of input image files in standard FITS or CASA format. From these, PySe provides a list of found sources; information such as the calculated background image, source list in different formats (e.g. text, region files importable in DS9), and other data may be saved. PySe can be integrated into a pipeline; it was originally written as part of the LOFAR Transient Detection Pipeline (TraP, ascl:1412.011).

  18. Linkages between Icelandic Low position and SE Greenland winter precipitation

    Science.gov (United States)

    Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

    2015-12-01

    Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

  19. SE and ENEL - One Year Together One Year after Privatization

    International Nuclear Information System (INIS)

    Anon

    2007-01-01

    In Bratislava, one year ago, exactly in April 28, the privatization deal of a 66% stake in Slovenske elektrarne (SE) was finally closed. The Slovak government and the Italian company ENEL signed final documents and ENEL thus definitely entered into SE. In May 2006, Miroslav Pikus, a former CEO, was replaced by Marco Arcelli, who, as a regional manager for Slovakia, had been preparing the entry of ENEL into SE since March 2005. Not only did he sometimes cook for us, in his 'kitchen' but also there were prepared 160 investment projects, e.g the improvement of nuclear safety and resistance of the Bohunice power plant, electricity sale through the so-called 'virtual power plant', ensuring a non-attended operation in hydro power plants, reconstruction and modernization of the Orava and Dobsina hydro power plants. (author)

  20. Teoria feminista: o desafio de tornar-se um paradigma

    Directory of Open Access Journals (Sweden)

    Mirian Santos Paiva

    1997-12-01

    Full Text Available Partindo da crise do paradigma tradicional e tendo como epicentro a crítica feminista, este trabalho tenta mostrar o desafio que enfrenta a teoria feminista para tornar-se um novo paradigma e para tanto realiza-se uma pesquisa bibliográfica, consubstanciada na literatura pertinente ao tema. Evidencia-se que o desafio de ser um paradigma em ascensão faz com que esta teoria enfrente problemas teóricos, conceituais e metodológicos que precisam de um esforço conjunto para serem aprofundados e resolvidos. Todavia, o desenvolvimento desta teoria não depende apenas do mundo acadêmico, mas está também atrelado a mudanças na estrutura social, pois, de uma sociedade mais igualitária, mais facilmente emergirá um conhecimento sem dominação de gênero.