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Sample records for experiment engineered barriers

  1. Engineered barrier experiment. Power control and data acquisition systems

    International Nuclear Information System (INIS)

    Alberdi, J.; Barcala, J.M.; Gamero, E.; Martin, P.L.; Molinero, A.; Navarrete, J.J.; Yuste, C.

    1997-01-01

    The engineered barrier concept for the storage of radioactive wastes is being tested at almost full scale at CIEMAT facilities. A data acquisition and control is an element of this experiment. This system would be operating for next three years. (Author)

  2. Engineered barriers: current status

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.P.

    1988-01-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  3. Construction and operational experiences of engineered barrier test facility for near surface disposal of LILW

    International Nuclear Information System (INIS)

    Park, Jin Beak; Park, Se Moon; Kim, Chang Lak

    2003-01-01

    Engineered barrier test facility is specially designed to demonstrate the performance of engineered barrier system for the near-surface disposal facility under the domestic environmental conditions. Comprehensive measurement systems are installed within each test cell. Long-and short-term monitoring of the multi-layered cover system can be implemented according to different rainfall scenarios with artificial rainfall system. Monitoring data on the water content, temperature, matric potential, lateral drainage and percolation of cover-layer system can be systematically managed by automatic data acquisition system. The periodic measurement data are collected and will be analyzed by a dedicated database management system, and provide a basis for performance verification of the disposal cover design

  4. Development of engineered barrier

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Kwan Sik; Cho, Won Jin; Lee, Jae Owan; Kim, Seung Soo; Kang, Mu Ja

    1999-03-01

    Engineered barrier development was carried out into the three research fields : waste form, disposal container, and buffer. The waste form field dealt with long-term leaching tests with borosilicate waste glasses surrounded by compacted bentonite. The leach rate decreased with increasing time, and was higher for the waste specimen rich in U and Na. In the container field, preliminary concepts of disposal containers were recommended by conducting structural analysis, thermal analysis, and shielding analysis, and major properties of stainless steel, copper, and titanium as a container material were surveyed. The sensitization degrees of SUS 316 and316L were lower than those of SUS 304 and 304L, respectively. The crevice corrosion of sensitized stainless steel was sensitive to the content of salt. Researches into the buffer included establishment of its performance criteria followed by investigating major properties of buffer using potential material in Korea. Experiments were made for measuring hydraulic conductivities, swelling properties, mechanical properties, thermal conductivities, pore-water chemistry properties, and adsorption properties was also investigated. (author)

  5. Development of engineered barrier

    International Nuclear Information System (INIS)

    Chun, Kwan Sik; Cho, Won Jin; Lee, Jae Owan; Kim, Seung Soo; Kang, Mu Ja

    1999-03-01

    Engineered barrier development was carried out into the three research fields : waste form, disposal container, and buffer. The waste form field dealt with long-term leaching tests with borosilicate waste glasses surrounded by compacted bentonite. The leach rate decreased with increasing time, and was higher for the waste specimen rich in U and Na. In the container field, preliminary concepts of disposal containers were recommended by conducting structural analysis, thermal analysis, and shielding analysis, and major properties of stainless steel, copper, and titanium as a container material were surveyed. The sensitization degrees of SUS 316 and 316L were lower than those of SUS 304 and 304L, respectively. The crevice corrosion of sensitized stainless steel was sensitive to the content of salt. Researches into the buffer included establishment of its performance criteria followed by investigating major properties of buffer using potential material in Korea. Experiments were made for measuring hydraulic conductivities, swelling properties, mechanical properties, thermal conductivities, pore-water chemistry properties, and adsorption properties was also investigated. (author)

  6. Performance of engineered barriers

    International Nuclear Information System (INIS)

    Rajaram, V.; Dean, P.V.; McLellan, S.A.

    1997-01-01

    Engineered barriers, both vertical and horizontal, have been used to isolate hazardous wastes from contact, precipitation, surface water and groundwater. The primary objective of this study was to determine the performance of subsurface barriers installed throughout the U.S. over the past 20 years to contain hazardous wastes. Evaluation of Resource Conservation and Recovery Act (RCRA) Subtitle C or equivalent caps was a secondary objective. A nationwide search was launched to select hazardous waste sites at which vertical barrier walls and/or caps had been used as the containment method. None of the sites selected had an engineered floor. From an initial list of 130 sites, 34 sites were selected on the basis of availability of monitoring data for detailed analysis of actual field performance. This paper will briefly discuss preliminary findings regarding the design, construction quality assurance/construction quality control (CQA/CQC), and monitoring at the 34 sites. In addition, the short-term performance of these sites (less than 5 years) is presented since very little long-term performance data was available

  7. Design studies on the engineered barrier system and on the in-situ experiments under the conditions of geological environment in Horonobe

    International Nuclear Information System (INIS)

    Kurihara, Yuji; Yui, Mikazu; Tanai, Kenji

    2004-04-01

    Following studies have been done in this papers in order to apply the technologies based on H12 report to the actual geological conditions of Horonobe underground research laboratory. 1) Reconsidering the process of repository design, the design process charts of a repository were presented. In the H12 report, the design process of the engineering barrier system was followed by the facility design process. In this paper, the both processes were placed in parallel position. 2) The relation between geological conditions and the performance of engineering barrier systems and the specifications of engineering barrier systems was arranged and the geological information needed for design of engineering barrier were selected. 3) The appropriate form of geological information as input-data for design were showed and the procedure for setting input-data was presented. 4) Based on the state of geological investigations at Horonobe, mechanical input-data were arranged for the design of the in-situ experiments on engineered barrier system at HORONOBE. 5) The stability of the hall for the in-situ experiments was studied by numerical analysis and the results indicated that there are difference in stability between the depth of 500 m and 570 m. (author)

  8. FEBEX: Full-Scale engineered barriers experiment in crystalline host-rock: preoperational phase. Synthesized report

    International Nuclear Information System (INIS)

    1997-01-01

    The FEBEX project is being cofinanced by the EC under contract F 14WCT950006. In addition to the EC, seven partners from three countries of the EU. (France, Germany, and Spain) as well as one from EFTA (Switzerland) are participating in the project. ENRESA is the coordinating partner with NAGRA assisting in coordinating some aspects. The project consists of two large-scale tests and a series of complimentary laboratory tests. The work is being executed by the following organizations: CIEMAT, AITEMIN, UP-DIT (CIMNE), ULC, CSIC-Zaidin, and UPM (SPAIN) ANDRA and G.3S (FRANCE) GRS (GERMANY). This report includes a synthesized description of the experiment from its conception through the installation of the two large-scale tests (from the middle of 1994 to the beginning of 1997, preoperation stage). The experiment is described in detail in a series of specific reports. (Author)

  9. Engineered barriers: current status 1989

    International Nuclear Information System (INIS)

    Atkinson, A.; Marsh, G.B.

    1989-06-01

    This report summarises the current state of research relevant to assessing the performance of engineered barriers made of steel and concrete in radioactive waste repositories. The objective of these barriers is to contain substantially the radionuclides within them by providing both physical and chemical impediment to their release. The physical barriers are of most value for highly soluble isotopes with relatively short half-lives (eg 137 Cs), since they can provide a measure of containment until a large fraction of the activity has decayed. In addition they can facilitate retrievability for some period after disposal. The chemical barriers operate by beneficial conditioning of the near field groundwater and providing sites for sorption of radionuclides. Both of these reduce the aqueous concentration of radionuclides in the near field. (author)

  10. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J.; Alonso, E.; Alheid, H.-J.; Bluemling, P.

    2007-01-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm 3 of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10 -12 m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm 3 ) serve well to demonstrate the achievable densities expected in the real world setting. The artificial

  11. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J. C. [Empresa Nacional de Residuos Radioactivos SA (ENRESA), Madrid (Spain); Garcia-Sineriz, J. [Asociacion para la Investigacion y Desarollo Industrial de los Recursos Naturales (AITEMIN), Madrid (Spain); Alonso, E. [Centre Internacional de Metodos Numerics en Ingenyeria (CIMNE), Barcelona (Spain); Alheid, H.-J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bluemling, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland)

    2007-07-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm{sup 3} of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10{sup -12} m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm{sup 3}) serve well to demonstrate the achievable densities expected in the real world setting. The

  12. Engineered barrier emplacement experiment in Opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  13. Engineered barrier emplacement experiment in opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  14. Mont Terri Project - Heater experiment, engineered barriers emplacement and ventilations tests. No 1 - Swiss Geological Survey, Bern, 2007

    International Nuclear Information System (INIS)

    Bossart, P.; Nussbaum, C.

    2007-01-01

    The international Mont Terri project started in January 1996. Research is carried out in the Mont Terri rock laboratory, an underground facility near the security gallery of the Mont Terri motorway tunnel (vicinity of St-Ursanne, Canton of Jura, Switzerland). The aim of the project is the geological, hydrogeological, geochemical and geotechnical characterisation of a clay formation, specifically of the Opalinus Clay. Twelve Partners from European countries and Japan participate in the project. These are ANDRA, BGR, CRIEPI, ENRESA, GRS, HSK, IRSN, JAEA, NAGRA, OBAYASHI, SCK.CEN and swisstopo. Since 2006, swisstopo acts as operator of the rock laboratory and is responsible for the implementation of the research programme decided by the partners. The three following reports are milestones in the research history of the Mont Terri project. It was the first time that an in-situ heating test with about 20 observation boreholes over a time span of several years was carried out in a clay formation. The engineered barrier emplacement experiment has been extended due to very encouraging measurement results and is still going on. The ventilation test was and is a challenge, especially in the very narrow microtunnel. All three projects were financially supported by the European Commission and the Swiss State Secretariat for Education and Research. The three important scientific and technical reports, which are presented in the following, have been provided by a number of scientists, engineers and technicians from the Partners, but also from national research organisations and private contractors. Many fruitful meetings where held, at the rock laboratory and at other facilities, not to forget the weeks and months of installation and testing work carried out by the technicians and engineers. The corresponding names and organisations are listed in detail in the reports. Special thanks are going to the co-ordinators of the three projects for their motivation of the team during

  15. Collection of measurement data from in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. FY2014

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Nakayama, Mariko; Kobayashi, Masato

    2015-09-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, “Geoscientific Research” and “Research and Development on Geological Disposal Technologies”, and proceeds in three overlapping phases, “Phase I: Surface-based investigations”, “Phase II: Investigations during tunnel excavation” and “Phase III: Investigations in the underground facilities”, over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at G.L.-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal – Hydrological – Mechanical – Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report summarizes the measurement data acquired from the EBS experiment from December, 2014 to March, 2015. The summarized data of the EBS experiment will be published periodically. A CD-ROM is attached as an appendix. (J.P.N)

  16. Collection of measurement data from in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. FY2015

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Nakayama, Mariko; Kobayashi, Masato

    2016-07-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, 'Geoscientific Research' and 'Research and Development on Geological Disposal Technologies', and proceeds in three overlapping phases, 'Phase I: Surface-based investigations', 'Phase II: Investigations during tunnel excavation' and 'Phase III: Investigations in the underground facilities', over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at G.L.-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal - Hydrological - Mechanical - Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report summarizes the measurement data acquired from the EBS experiment from December, 2014 to March, 2016. The summarized data of the EBS experiment will be published periodically. A CD-ROM is attached as an appendix. (J.P.N)

  17. Engineered Barrier Test Facility status report, 1984

    International Nuclear Information System (INIS)

    Phillips, S.J.; Adams, M.R.; Gilbert, T.W.; Meinhardt, C.C.; Mitchell, R.M.; Waugh, W.J.

    1985-02-01

    This report provides a general summary of activities completed to date at the Hanford Engineered Barrier Test Facility. This facility is used to test and compare construction practices and performance of alternative designs of engineered barrier cover systems. These cover systems are being evaluated for potential use for isolation and confinement of buried waste disposal structures

  18. Poro-elasto-plastic behaviour of dry compacted Fo-Ca clay: experiment and modelling. Application to the re-saturation of an engineered clay barrier

    International Nuclear Information System (INIS)

    Lassabatere, Th.; Imbert, Ch.; Etile, M.A.

    1999-01-01

    Many projects of underground repositories for high level radioactive waste involve an engineered clay barrier, placed between the waste canister and the surrounding rock. When hydrated, this barrier seals the gap and provides a good watertightness. The natural clay powder, dried and compacted, exhibits hydro-mechanical couplings during the hydration. Such a coupled behaviour, interesting for the industrial application, has been clearly demonstrated by many studies and laboratory experiments. But the modelling of this behaviour, in order to predict the hydration of the clay barrier, is difficult. A coupled modelling, based, at a macroscopic scale, on the thermodynamics of unsaturated porous media, is proposed. This thermodynamical model founds a general framework for non linear poro-elastic and poro-elasto-plastic coupled behaviours. The symmetries of this coupling, induced by this thermodynamical framework, let us take into account the often neglected influence of the mechanical state on the hydraulic problem of the re-saturation of the clay. The complete resolution of the flow problem, coupled with the mechanical behaviour, leads us to study the influence of the rheological behaviour chosen for the clay (elastic - linear or no linear -, or elastoplastic) on the evaluation of the duration of the re-saturation of the clay barrier). (authors)

  19. Design of engineered sorbent barriers

    International Nuclear Information System (INIS)

    Jones, E.O.; Freeman, H.D.

    1988-08-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper will cover the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier. 8 refs., 6 figs., 1 tab

  20. Design of engineered sorbent barriers

    International Nuclear Information System (INIS)

    Jones, E.O.; Freeman, H.D.

    1988-01-01

    A sorbent barrier uses sorbent material such as activated carbon or natural zeolites to prevent the migration of radionuclides from a low-level waste site to the aquifer. The sorbent barrier retards the movement of radioactive contaminants, thereby providing time for the radionuclides to decay. Sorbent barriers can be a simple, effective, and inexpensive method for reducing the migration of radionuclides to the environment. Designing a sorbent barrier consists of using soil and sorbent material properties and site conditions as input to a model which will determine the necessary sorbent barrier thickness to meet contaminant limits. The paper covers the following areas: techniques for measuring sorption properties of barrier materials and underlying soils, use of a radionuclide transport model to determine the required barrier thickness and performance under a variety of site conditions, and cost estimates for applying the barrier

  1. International Collaboration Activities on Engineered Barrier Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-08-31

    The Used Fuel Disposition Campaign (UFDC) within the DOE Fuel Cycle Technologies (FCT) program has been engaging in international collaborations between repository R&D programs for high-level waste (HLW) disposal to leverage on gathered knowledge and laboratory/field data of near- and far-field processes from experiments at underground research laboratories (URL). Heater test experiments at URLs provide a unique opportunity to mimetically study the thermal effects of heat-generating nuclear waste in subsurface repository environments. Various configurations of these experiments have been carried out at various URLs according to the disposal design concepts of the hosting country repository program. The FEBEX (Full-scale Engineered Barrier Experiment in Crystalline Host Rock) project is a large-scale heater test experiment originated by the Spanish radioactive waste management agency (Empresa Nacional de Residuos Radiactivos S.A. – ENRESA) at the Grimsel Test Site (GTS) URL in Switzerland. The project was subsequently managed by CIEMAT. FEBEX-DP is a concerted effort of various international partners working on the evaluation of sensor data and characterization of samples obtained during the course of this field test and subsequent dismantling. The main purpose of these field-scale experiments is to evaluate feasibility for creation of an engineered barrier system (EBS) with a horizontal configuration according to the Spanish concept of deep geological disposal of high-level radioactive waste in crystalline rock. Another key aspect of this project is to improve the knowledge of coupled processes such as thermal-hydro-mechanical (THM) and thermal-hydro-chemical (THC) operating in the near-field environment. The focus of these is on model development and validation of predictions through model implementation in computational tools to simulate coupled THM and THC processes.

  2. The in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory. Examination of backfill material using muck from URL construction

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Ohno, Hirokazu; Tanai, Kenji; Fujita, Tomoo; Sugita, Yutaka

    2016-06-01

    The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, “Geoscientific Research” and “Research and Development on Geological Disposal Technologies”, and proceeds in three overlapping phases, “Phase I: Surface-based investigations”, “Phase II: Investigations during tunnel excavation” and “Phase III: Investigations in the underground facilities”, over a period of around 20 years. Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) was prepared from 2013 to 2014 fiscal year at G.L.-350m gallery (Niche No.4), and heating by electric heater in simulated overpack started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal – Hydrological – Mechanical – Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. In EBS experiment, the backfill material using mixture of bentonite and muck from Horonobe URL construction was used for backfilling a part of Niche No.4. This report shows the results of properties of the backfill material, confirmation test of compaction method and making backfill material block, and so on. From these results, it was confirmed that the backfill material would satisfy target value of the permeability and the swelling pressure. (author)

  3. Barrier Engineered Quantum Dot Infrared Photodetectors

    Science.gov (United States)

    2015-06-01

    251108. 6. Barve, Ajit V., Saumya Sengupta, Jun Oh Kim, John Montoya , Brianna Klein, Mohammad Ali Shirazi, Marziyeh Zamiri et al., "Barrier selection... H . Kim, Z-B. Tian, and Sanjay Krishna. "Barrier Engineered Infrared Photodetectors Based on Type-II InAs/GaSb Strained Layer Superlattices." (2013

  4. Engineering kinetic barriers in copper metallization

    International Nuclear Information System (INIS)

    Huang Hanchen; Wei, H.L.; Woo, C.H.; Zhang, X.X.

    2002-01-01

    In metallization processes of integrated circuits, it is desirable to deposit the metal lines (aluminum or copper) fast and at low temperatures. However, the lines (films) usually consist of undesirable columns and voids, because of the absence of sufficient diffusion--a direct result of large kinetic barriers. Following the proposal and realization of the three-dimensional Ehrlich-Schwoebel (3D ES) barrier, we present here a method to engineer this kinetic barrier so as to improve quality of deposited copper films. We deposit copper films by magnetron sputtering, characterize the film structure and texture by using the scanning electron microscope and the x-ray diffraction, respectively. Taking indium as surfactant during copper deposition, we have achieved much better density and bottom coverage of copper filled trenches. The characterizations show that the improvement is the result of the 3D ES barrier reduction caused by indium addition. Engineering the 3D ES barrier therefore leads to improved film quality

  5. Barriers to student success in engineering education

    Science.gov (United States)

    Boles, Wageeh; Whelan, Karen

    2017-07-01

    In the UK, the USA and Australia, there have been calls for an increase in the number of engineering graduates to meet the needs of current global challenges. Universities around the world have been grappling with how to both attract more engineering students and to then retain them. Attrition from engineering programmes is disturbingly high. This paper reports on an element of research undertaken through an Australian Learning and Teaching Council-funded Fellowship that investigated the factors leading to student attrition in engineering programmes, by identifying barriers to student success. Here, we contrast a review of the literature related to student barriers and success with student perceptions, gathered through a series of focus groups and interviews at three Australian universities. We also present recommendations for action to try to remove barriers to student success.

  6. Validation of the Performance of Engineered Barriers

    International Nuclear Information System (INIS)

    Choi, Jongwon; Cho, Wonjin; Kwon, Sangki

    2012-04-01

    To study the thermal-hydro-mechanical (THM) and thermal-hydro-mechanical-chemical (THMC) behavior of engineered barrier system (EBS), the engineering scale experiments, KENTEX and KENTEX-C were conducted to investigate THM and THMC behavior in the buffer. The computer modelling and simulation programmes were developed to analyze the distribution of temperature, water content, total pressure and the measured data on the migration behavior of anion and cation. In-situ heater test were performed to investigate the effect of the ventilation, thermal characteristics of EDZ, and effect of the anisotropy of rock mass and joint in addition to the investigation of the thermo-mechanical behavior in rock mass. The geophysics exploration and in-situ field tests were carried out to investigate the range of EDZ and its effects on the mechanical properties of rock. Subsequently, crack propagation characteristics and dynamic material properties of jointed rock mass in KURT were measured. Concurrently, the in-situ experiments were performed in the KURT to investigate the change of hydraulic properties in EDZ. The stainless steel molds are manufactured to fabricate the buffer blocks with various shapes. The experiments are carried out to check the mechanical properties, the workability for installation of the fabricated blocks and to investigate the resaturation processes. The state of the technology on application of cementitious materials to the HLW repository was analysed and the optimized low-pH cement recipe was obtained. And the material properties of low-pH and high-pH cement grouts were evaluated based on the grout recipes of ONKALO in Finland. The KURT was operated, and the various technical supports were provided to the in-situ experiments which were carried at KURT

  7. Thermal barrier coatings application in diesel engines

    Science.gov (United States)

    Fairbanks, J. W.

    1995-01-01

    Commercial use of thermal barrier coatings in diesel engines began in the mid 70's by Dr. Ingard Kvernes at the Central Institute for Industrial Research in Oslo, Norway. Dr. Kvernes attributed attack on diesel engine valves and piston crowns encountered in marine diesel engines in Norwegian ships as hot-corrosion attributed to a reduced quality of residual fuel. His solution was to coat these components to reduce metal temperature below the threshold of aggressive hot-corrosion and also provide protection. Roy Kamo introduced thermal barrier coatings in his 'Adiabatic Diesel Engine' in the late 70's. Kamo's concept was to eliminate the engine block water cooling system and reduce heat losses. Roy reported significant performance improvements in his thermally insulated engine at the SAE Congress in 1982. Kamo's work stimulates major programs with insulated engines, particularly in Europe. Most of the major diesel engine manufacturers conducted some level of test with insulated combustion chamber components. They initially ran into increased fuel consumption. The German engine consortium had Prof. Woschni of the Technical Institute in Munich. Woschni conducted testing with pistons with air gaps to provide the insulation effects. Woschni indicated the hot walls of the insulated engine created a major increase in heat transfer he refers to as 'convection vive.' Woschni's work was a major factor in the abrupt curtailment of insulated diesel engine work in continental Europe. Ricardo in the UK suggested that combustion should be reoptimized for the hot-wall effects of the insulated combustion chamber and showed under a narrow range of conditions fuel economy could be improved. The Department of Energy has supported thermal barrier coating development for diesel engine applications. In the Clean Diesel - 50 Percent Efficient (CD-50) engine for the year 2000, thermal barrier coatings will be used on piston crowns and possibly other components. The primary purpose of the

  8. FEBEX-DP. Dismantling the ''full-scale engineered barrier experiment'' after 18 years of operation at the Grimsel Test Site, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Kober, Florian; Gaus, Irina [Nagra, Wettingen (Switzerland)

    2015-07-01

    The FEBEX experiment at the Grimsel Test Site (GTS) consists of an in-situ full-scale engineered barrier system (EBS) test for the disposal of high-level waste (HLW). It is performed under natural conditions in crystalline rock in which the canisters are placed horizontally in drifts and are surrounded by a clay barrier constructed of highly compacted bentonite blocks. A partial dismantling and sampling of the EBS was carried out during 2002. Heating of the FEBEX started in 1997 and since then a constant temperature of 100 deg C has been maintained, while the bentonite buffer has been slowly hydrating in a natural way. A total of 632 sensors in the bentonite barrier, the rock mass, the heaters and the service zone record temperature, water saturation, humidity, total pressure, displacement, and water pressure. The hydration pattern is relatively symmetric, with no major differences along the axis. Although the host rock is characterized by heterogeneities with zones of higher permeability, the resaturation process is driven by the suction of the bentonite rather than by the availability of water in the rock, especially in the early phase. After 17 years, the water content in the buffer close to the heater still continues to increase slowly. The hydraulic pore pressures in the buffer and the geosphere have practically stabilized. The total pressure in general continues to increase in most points into the buffer, where in some parts pressures of over 6 MPa are registered. The long monitoring phase and the partial dismantling in 2002 indicate that the EBS has largely performed as expected and the major processes and couplings affecting the buffer saturation during the initial thermal period identified prior to the start of the experiment have been confirmed. A comprehensive report documents and reviews the state of the FEBEX (Lanyon and Gaus, 2013). After 18 years of operation the experiment will be excavated and dismantled in 2015. The main objectives of the FEBEX

  9. Engineered Barrier System: Physical and Chemical Environment

    International Nuclear Information System (INIS)

    Dixon, P.

    2004-01-01

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

  10. Systems study on engineered barriers: barrier performance analysis

    International Nuclear Information System (INIS)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed

  11. Systems study on engineered barriers: barrier performance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stula, R.T.; Albert, T.E.; Kirstein, B.E.; Lester, D.H.

    1980-09-01

    A performance assessment model for multiple barrier packages containing unreprocessed spent fuel has been modified and applied to several package designs. The objective of the study was to develop information to be used in programmatic decision making concerning engineered barrier package design and development. The assessment model, BARIER, was developed in previous tasks of the System Study on Engineered Barriers (SSEB). The new version discussed in this report contains a refined and expanded corrosion rate data base which includes pitting, crack growth, and graphitization as well as bulk corrosion. Corrosion rates for oxic and anoxic conditions at each of the two temperature ranges are supplied. Other improvements include a rigorous treatment of radionuclide release after package failure which includes resistance of damaged barriers and backfill, refined temperature calculations that account for convection and radiation, a subroutine to calculate nuclear gamma radiation field at each barrier surface, refined stress calculations with reduced conservatism and various coding improvements to improve running time and core usage. This report also contains discussion of alternative scenarios to the assumed flooded repository as well as the impact of water exclusion backfills. The model was used to assess post repository closure performance for several designs which were all variation of basic designs from the Spent Unreprocessed Fuel (SURF) program. Many designs were found to delay the onset of leaching by at least a few hundreds of years in all geologic media. Long delay times for radionuclide release were found for packages with a few inches of sorption backfill. Release of uranium, plutonium, and americium was assessed.

  12. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock. Final report

    International Nuclear Information System (INIS)

    Alberdi, J.; Barcala, J. M.; Campos, R.; Cuevas, A. M.; Fernandez, E.

    2000-01-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  13. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock

    Energy Technology Data Exchange (ETDEWEB)

    Alberid, J; Barcala, J M; Campos, R; Cuevas, A M; Fernandez, E [Ciemat. Madrid (Spain)

    2000-07-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  14. Engineered barriers for radioactive waste confinement

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2011-09-01

    Full Text Available Nuclear power plants generate long-lived radioactive waste of high toxicity. The security assessment of repositories destined to definitive confinement of radioactive waste has been studied for several decades. Deep geological repositories are technically feasible and begin to be built by some pioneer countries. The scientific evaluation of interactions between the different engineered barriers is studied by laboratory experiments, natural analogues and modeling studies. The three methods are able to represent and validate the main geochemical processes that take place in the near field. This paper reviews the scientific and technical basis of the concept of geological disposal, with particular focus on the methods of study applied to the evaluation of geochemical stability of the bentonite barrier.

    Las centrales nucleares generan residuos radiactivos de elevada peligrosidad y permanencia en el tiempo. La evaluación de la seguridad de repositorios destinados al alojamiento definitivo de estos residuos lleva estudiándose desde hace varias décadas. El almacenamiento geológico es técnicamente factible y empieza ya a desarrollarse en países pioneros. La evaluación científica de las interacciones entre las distintas barreras de ingeniería se estudia mediante ensayos de laboratorio, análisis de análogos naturales y modelos teóricos. Las tres vías de estudio son capaces de representar y validar los principales procesos geoquímicos que tienen lugar en el campo cercano al repositorio. Este artículo revisa los fundamentos científicos y técnicos del concepto de almacenamiento geológico detallando, en particular, los métodos de estudio aplicados a la evaluación de la estabilidad geoquímica de la barrera de bentonita.

  15. Near-Surface Engineered Environmental Barrier Integrity

    International Nuclear Information System (INIS)

    Piet, S.J.; Breckenridge, R.P.

    2002-01-01

    The INEEL Environmental Systems Research and Analysis (ESRA) program has launched a new R and D project on Near-Surface Engineered Environmental Barrier Integrity to increase knowledge and capabilities for using engineering and ecological components to improve the integrity of near-surface barriers used to confine contaminants from the public and the environment. The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions and enable improved solutions for future cleanup decisions. The research is planned to (a) improve the knowledge of degradation mechanisms (weathering, biological, geological, chemical, radiological, and catastrophic) in times shorter than service life, (b) improve modeling of barrier degradation dynamics, (c) develop sensor systems to identify degradation prior to failure, and (d) provide a better basis for developing and testing of new barrier systems to increase reliability and reduce the risk of failure. Our project combine s selected exploratory studies (benchtop and field scale), coupled effects accelerated aging testing and the meso-scale, testing of new monitoring concepts, and modeling of dynamic systems. The performance of evapo-transpiration, capillary, and grout-based barriers will be examined

  16. Prototype Engineered Barrier System Field Tests

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Beatty, J.; Buscheck, T.A.

    1989-01-01

    This paper presents selected preliminary results obtained during the first 54 days of the Prototype Engineered Barrier System Field Tests (PEBSFT) that are being performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT). The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The PEBSFTs are being conducted to evaluate the applicability of measurement techniques, numerical models, and procedures for future investigations that will be conducted in the Exploratory Shaft Facilities of the Yucca Mountain Project (YMP). The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures, gas pressures, and rock mass gas-phase humidity. 10 refs., 12 figs

  17. Engineered Barrier System: Physical and Chemical Environment

    Energy Technology Data Exchange (ETDEWEB)

    P. Dixon

    2004-04-26

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  18. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    R. Jarek

    2004-11-23

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

  19. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    International Nuclear Information System (INIS)

    Jarek, R.

    2004-01-01

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports

  20. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    International Nuclear Information System (INIS)

    G.H. Nieder-Westermann

    2005-01-01

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports

  1. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    G.H. Nieder-Westermann

    2005-04-07

    The purpose of this report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The abstraction model is used in the total system performance assessment for the license application (TSPA LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of these abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2004 [DIRS 171156], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports.

  2. Reliability modeling of an engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.; Flueck, J.A.

    1993-01-01

    The Weibull distribution is widely used in reliability literature as a distribution of time to failure, as it allows for both increasing failure rate (IFR) and decreasing failure rate (DFR) models. It has also been used to develop models for an engineered barrier system (EBS), which is known to be one of the key components in a deep geological repository for high level radioactive waste (HLW). The EBS failure time can more realistically be modelled by an IFR distribution, since the failure rate for the EBS is not expected to decrease with time. In this paper, we use an IFR distribution to develop a reliability model for the EBS

  3. Reliability modeling of an engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.; Flueck, J.A.

    1993-01-01

    The Weibull distribution is widely used in reliability literature as a distribution of time to failure, as it allows for both increasing failure rate (IFR) and decreasing failure rate (DFR) models. It has also been used to develop models for an engineered barrier system (EBS), which is known to be one of the key components in a deep geological repository for high level radioactive waste (HLW). The EBS failure time can more realistically be modelled by an IFR distribution, since the failure rate for the EBS is not expected to decrease with time. In this paper, an IFR distribution is used to develop a reliability model for the EBS

  4. Electrolyte diffusion in compacted montmorillonite engineered barriers

    International Nuclear Information System (INIS)

    Jahnke, F.M.; Radke, C.J.

    1985-09-01

    The bentonite-based engineered barrier or packing is a proposed component of several designs conceived to dispose of high-level nuclear waste in geologic repositories. Once radionuclides escape the waste package, they must first diffuse through the highly impermeable clay-rich barrier before they reach the host repository. To determine the effectiveness of the packing as a sorption barrier in the transient release period and as a mass-transfer barrier in the steady release period over the geologic time scales involved in nuclear waste disposal, a fundamental understanding of the diffusion of electrolytes in compacted clays is required. We present, and compare with laboratory data, a model quantifying the diffusion rates of cationic cesium and uncharged tritium in compacted montmorillonite clay. Neutral tritium characterizes the geometry (i.e., tortuosity) of the particulate gel. After accounting for cation exchange, we find that surface diffusion is the dominant mechanism of cation transport, with an approximate surface diffusion coefficient of 2 x 10 -6 cm 2 /s for cesium. This value increases slightly with increasing background ionic strength. The implications of this work for the packing as a migration barrier are twofold. During the transient release period, K/sub d/ values are of little importance in retarding ion migration. This is because sorption also gives rise to a surface diffusion path, and it is surface diffusion which controls the diffusion rate of highly sorbing cations in compacted montmorillonite. During the steady release period, the presence of surface diffusion leads to a flux through the packing which is greatly enhanced. In either case, if surface diffusion is neglected, the appropriate diffusion coefficient of ions in compacted packing will be in considerable error relative to current design recommendations. 11 refs., 4 figs., 1 tab

  5. Thermal barrier coatings - Technology for diesel engines

    International Nuclear Information System (INIS)

    Harris, D.H.; Lutz, J.

    1988-01-01

    Thermal Barrier Coatings (TBC) are a development of the aerospace industry primarily aimed at hot gas flow paths in turbine engines. TBC consists of zirconia ceramic coatings applied over (M)CrAlY. These coatings can provide three benefits: (1) a reduction of metal surface operating temperatures, (2) a deterrent to hot gas corrosion, and (3) improved thermal efficiencies. TBC brings these same benefits to reciprocal diesel engines but coating longevity must be demonstrated. Diesels require thicker deposits and have challenging geometries for the arc-plasma spray (APS) deposition process. Different approaches to plasma spraying TBC are required for diesels, especially where peripheral edge effects play a major role. Bondcoats and ceramic top coats are modified to provide extended life as determined by burner rig tests, using ferrous and aluminum substrates

  6. The Blood-Brain Barrier: An Engineering Perspective

    Directory of Open Access Journals (Sweden)

    Andrew eWong

    2013-08-01

    Full Text Available It has been more than 100 years since Paul Ehrlich reported that various water-soluble dyes injected into the circulation did not enter the brain. Since Ehrlich’s first experiments, only a small number of molecules, such as alcohol and caffeine have been found to cross the blood-brain barrier, and it remains the major roadblock to treatment of many central nervous system diseases. At the same time, many central nervous system diseases are associated with disruption of the blood-brain barrier that can lead to changes in permeability, modulation of immune cell transport, and trafficking of pathogens into the brain. Therefore advances in our understanding of the structure and function of the blood-brain barrier are key to advances in treatment of a wide range of central nervous system diseases. Over the past 10 years it has become recognized that the blood-brain barrier is a complex dynamic system that involves biomechanical and biochemical signaling between the vascular system and the brain. Here we reconstruct the structure, function, and transport properties of the blood-brain barrier from an engineering perspective. New insight into the physics of the blood-brain barrier could ultimately lead to clinical advances in the treatment of central nervous system diseases.

  7. Experimental Approach of Fault Movement on an Engineered Barrier System

    International Nuclear Information System (INIS)

    Lee, Minsoo; Choi, Heuijoo; Kim, Heuna

    2012-01-01

    Safety evaluation of an engineered barrier system against fault movement at underground disposal region for high level waste (HLW) is tried using a miniature bore-shear apparatus. For the purpose, a miniature bore-shear apparatus simulating an EBS (engineered barrier system) was manufactured in 1/30 scale. And using the developed apparatus, bore-shear tests were performed twice. During the tests, pressure variations were checked at 6 points around buffer zone, and then a rotational angle of the test vessel was checked. The achieved pressure data were compared with those from analytical modeling, which is based on Drucker-Prager model. At initial shearing step, high pressure was recorded at some point but it decreased rapidly. For the better understanding of fault movement, the modification of an analytical model and the accumulation of experimental experience were required

  8. Experimental Approach of Fault Movement on an Engineered Barrier System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minsoo; Choi, Heuijoo; Kim, Heuna [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Safety evaluation of an engineered barrier system against fault movement at underground disposal region for high level waste (HLW) is tried using a miniature bore-shear apparatus. For the purpose, a miniature bore-shear apparatus simulating an EBS (engineered barrier system) was manufactured in 1/30 scale. And using the developed apparatus, bore-shear tests were performed twice. During the tests, pressure variations were checked at 6 points around buffer zone, and then a rotational angle of the test vessel was checked. The achieved pressure data were compared with those from analytical modeling, which is based on Drucker-Prager model. At initial shearing step, high pressure was recorded at some point but it decreased rapidly. For the better understanding of fault movement, the modification of an analytical model and the accumulation of experimental experience were required.

  9. Clays in natural and engineered barriers for radioactive waste confinement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Andra organised an International Symposium on the use of Natural and Engineered Clay-based Barriers for the Containment of Radioactive Waste hold at the Congress Centre of Tours, France, in March 2005. The symposium provided an opportunity to take stock of the potential properties of the clay-based materials present in engineered or natural barriers in order to meet the containment specifications of a deep geological repository for radioactive waste. It was intended for specialists working in the various disciplines involved with clays and clay based minerals, as well as scientists from agencies and organisations dealing with investigations on the disposal of high-level and long-lived radioactive waste. The themes of the Symposium included geology, geochemistry, transfers of materials, alteration processes, geomechanics, as well as the recent developments regarding the characterisation of clays, as well as experiments in surface and underground laboratories. The symposium consisted of plenary sessions, parallel specialized sessions and poster sessions. (author)

  10. Engineered barrier development for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    The BWIP Engineered Barrier Program has been developed to provide an integrated approach to the development of site-specific Engineered Barrier assemblages for a repository located in basalt. The goal of this program is to specify engineered and natural barriers which will ensure that nuclear and non-radioactive hazardous materials emplaced in a repository in basalt do not exceed acceptable rates of release to the biosphere. A wide range of analytical and experimental activities related to the basalt repository environment, waste package environment, waste/barrier/rock interactions, and barrier performance assessment provide the basis for selection of systems capable of meeting licensing requirements. Work has concentrated on specifying and testing natural and man-made materials which can be used to plug boreholes in basalt and which can be used as multiple barriers to surround nuclear waste forms and containers. The Engineered Barriers Program is divided into two major activities: multiple barrier studies and borehole plugging. 8 figures, 4 tables

  11. Preliminary engineering specifications for a test demonstration multilayer protective barrier cover system

    International Nuclear Information System (INIS)

    Phillips, S.J.; Gilbert, T.W.; Adams, M.R.

    1985-03-01

    This report presents preliminary engineering specifications for a test protective barrier cover system and support radiohydrology facility to be constructed at the Hanford Protective Barrier Test Facility (PBTF). Construction of this test barrier and related radiohydrology facility is part of a continuing effort to provide construction experience and performance evaluation of alternative barrier designs used for long-term isolation of disposed radioactive waste materials. Design specifications given in this report are tentative, based on interim engineering and computer simulation design efforts. Final definitive design specifications and engineering prints will be produced in FY 1986. 6 refs., 10 figs., 1 tab

  12. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    Energy Technology Data Exchange (ETDEWEB)

    R. Jarek

    2005-08-29

    The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The resulting seepage evaporation and gas abstraction models are used in the total system performance assessment for the license application (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2005 [DIRS 173782], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports. To be consistent with other project documents that address features, events, and processes (FEPs), Table 6.14.1 of the current report includes updates to FEP numbers and FEP subjects for two FEPs identified in the technical work plan (TWP) governing this report (BSC 2005 [DIRS 173782]). FEP 2.1.09.06.0A (Reduction-oxidation potential in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.06.0B (Reduction-oxidation potential in Drifts; see Table 6.14-1). FEP 2.1.09.07.0A (Reaction kinetics in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.07.0B (Reaction kinetics in Drifts; see Table 6.14-1). These deviations from the TWP are justified because they improve integration with FEPs

  13. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    International Nuclear Information System (INIS)

    R. Jarek

    2005-01-01

    The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. The resulting seepage evaporation and gas abstraction models are used in the total system performance assessment for the license application (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. This report develops and documents a set of abstraction-level models that describe the engineered barrier system physical and chemical environment. Where possible, these models use information directly from other reports as input, which promotes integration among process models used for TSPA-LA. Specific tasks and activities of modeling the physical and chemical environment are included in ''Technical Work Plan for: Near-Field Environment and Transport In-Drift Geochemistry Model Report Integration'' (BSC 2005 [DIRS 173782], Section 1.2.2). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system reports. To be consistent with other project documents that address features, events, and processes (FEPs), Table 6.14.1 of the current report includes updates to FEP numbers and FEP subjects for two FEPs identified in the technical work plan (TWP) governing this report (BSC 2005 [DIRS 173782]). FEP 2.1.09.06.0A (Reduction-oxidation potential in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.06.0B (Reduction-oxidation potential in Drifts; see Table 6.14-1). FEP 2.1.09.07.0A (Reaction kinetics in EBS), as listed in Table 2 of the TWP (BSC 2005 [DIRS 173782]), has been updated in the current report to FEP 2.1.09.07.0B (Reaction kinetics in Drifts; see Table 6.14-1). These deviations from the TWP are justified because they improve integration with FEPs documents. The updates

  14. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  15. Barrier bucket experiment at the AGS

    Directory of Open Access Journals (Sweden)

    M. Fujieda

    1999-12-01

    Full Text Available A barrier bucket experiment with two dedicated barrier cavities was performed at the Brookhaven AGS. One of the barrier cavities was a magnetic alloy (MA–loaded cavity and the other was a ferrite-loaded cavity. They generated a single sine wave with a peak voltage of 40 kV at a repetition rate of 351 kHz. A barrier rf system was established with these cavities and five bunches from the AGS booster were accumulated. A total of 3×10^{13} protons were stored without beam loss, and were successfully rebunched and accelerated. The longitudinal emittance growth was observed during accumulation by the barrier bucket, the blowup factor of which was about 3. The longitudinal mismatch between the rf bucket and the beam bunch was the main reason for the emittance growth. The potential distortions by beam loading of the ferrite cavity and the overshooting voltage of the MA cavity disturbed the smooth debunching.

  16. Safety engineering experiments of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Noboru

    1987-07-24

    The outline of large scale experiments carried out every year since 1969 to obtain fundamental data and then establish the safety engineering standards concerning the manufacturing, storage and transportation, etc. of all explosives was described. Because it becomes recently difficult to ensure the safety distance in powder magazines and powder plants, the sandwich structure with sand is thought to be suitable as the neighboring barrier walls. The special vertical structure for embankments to provide against a emergency explosion is effective to absorb the blast. Explosion behaviors such as initiating sensitivity, detonation, sympathetic detonation, and shock occurence of the ANFO explosives in place of dynamite and the slurry explosives were studied. The safety engineering standards for the manufacturing and application of explosives were studied to establish because accidents by tabacco fire are not still distinguished. Much data concerning early stage fire fighting, a large quantity of flooding and shock occurence from a assumption of ignition during machining in the propellants manufacturing plant, could be obtained. Basic studies were made to prevent pollution in blasting sites. Collected data are utilized for the safety administration after sufficient discussion. (4 figs, 2 tabs, 3 photos, 17 refs)

  17. Subterranean stress engineering experiments

    International Nuclear Information System (INIS)

    Campbell, J.R.; Colgate, S.A.; Wheat, B.M.

    1980-01-01

    The state of stress in a subterranean rock mass has classically been assumed to be constant at best. In soil with a high clay content, preconsolidation and drainage methods can lead to more stable foundation material, but methods for engineering the stresses in large masses of rock are not well known. This paper shows the results from an experiment designed to alter the in situ rock stress field in an oil shale mine. This was done by hydrofracturing the rock by use of a packed-well injection system and then propping the crack open with a thixotropic gel, which slowly hardened to the consistency of cement. Successive hydrofracture and high-pressure grouting resulted in an overstressed region. Well-head injection pressures, surface tilts, injection rates, and subterranean strains were measured and recorded on floppy disk by a Z-80 microprocessor. The results were then transmitted to the large computer system at the Los Alamos Scientific Laboratory (LASL). To put the data in a more useful form, computer-generated movies of the tilts and strains were made by use of computer graphics developed at LASL. The purpose of this paper is to present results from the Single Large Instrumented Test conducted in the Colony Oil Shale Mine near Rifle, Colorado. 13 figures

  18. Prototype Engineered Barrier System Field Tests (PEBSFT)

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Wilder, D.G.

    1991-02-01

    This progress report presents the interpretation of data obtained (up to November 1, 1988) from the Prototype Engineered Barrier System Field Tests (PEBSFT) that are being performed for the Yucca Mountain Project (YMP) in G-Tunnel within the Nevada Test site. The PEBSFTs are being conducted to evaluate the applicability of measurement techniques, numerical models, and procedures developed for the field tests for future investigations that will be conducted in the Exploratory Shaft Facilities, at a potential high-level radioactive waste repository site in Yucca Mountain. The primary objective of the tests is to provide the basis for determining whether tests planned for Yucca Mountain have the potential to be successful. Thirteen chapters discuss the following: mapping the electromagnetic permittivity and attenuation rate of the rock mass; changes in moisture content detected by the neutron logging probe; characterization of the in-situ permeability of the fractured tuff around the heater borehole; electrical resistance heater installed in a 30-cm borehole; relative humidity measurements; the operation, design, construction, calibration, and installation of a microwave circuit that might provide partial pressure information at temperatures in excess of 200 degree C (392 degree F); pressure and temperature measurements in the G-Tunnel; the moisture collection system, which attempts to collect steam that migrates into the heater borehole; The borehole television and borescope surveys that were performed to map the location, orientation, and aperture of the fractures intersecting the boreholes; preliminary scoping calculations of the hydrothermal conditions expected for this prototype test; the Data Acquisition System; and the results of the PEBSFT, preliminary interpretations of these results, and plans for the remainder of the test. Chapters have been indexed separately for inclusion on the data base

  19. Prototype Engineered Barrier System Field Test (PEBSFT)

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Buscheck, T.; Carlson, R.; Daily, W.; Lee, K.; Lin, Wunan; Mao, Nai-hsien; Ueng, Tzou-Shin; Wang, H.; Watwood, D.

    1991-08-01

    This final report represents a summary of data and interpretations obtained from the Prototype Engineered Barrier System Field Test (PEBSFT) performed in G-Tunnel within the Nevada Test Site. The PEBSFT was conducted to evaluate the applicability of measurement techniques, numerical models, and procedures developed for future field tests that will be conducted in the Exploratory Studies Facilities (ESF) at Yucca Mountain. The primary objective of the test was to provide a basis for determining whether tests planned for the ESF have the potential to be successful. Chapter 1 on high frequency electromagnetic tomography discusses the rock mass electromagnetic permittivity and attenuation rate changes that were measured to characterize the water distribution in the near field of a simulated waste container. The data are used to obtain quantitative estimates of how the moisture content in the rock mass changes during heating and to infer properties of the spatial variability of water distribution, leading to conclusions about the role of fractures in the system. Chapter 2 discusses the changes in rock moisture content detected by the neutron logging probe. Chapter 3 permeability tests discusses the characterization of the in-situ permeability of the fractured tuff around the borehole. The air permeability testing apparatus, the testing procedures, and the data analysis are presented. Chapter 4 describes the moisture collection system installed in the heater borehole to trap and measure the moisture volumes. Chapter 5 describes relative humidity measurements made with the thermocouple psychrometer and capacitance sensors. Chapter 6 discusses gas pressure measurements in the G-Tunnel, addressing the calibration and installation of piezoresistive-gaged transducers. Chapter 7 describes the calibration and installation of thermocouples for temperature measurements. Chapter 8 discusses the results of the PEBSFT

  20. Engineered Barrier Testing at the INEEL Engineered Barriers Test Facility: FY-1997 and FY-1998

    International Nuclear Information System (INIS)

    Keck, K. N.; Porro, I.

    1998-01-01

    Engineered barriers of two designs are being tested at the Engineered Barriers Test Facility (EBTF) at the Idaho National Engineering and Environmental Laboratory. This report describes the test facility, barrier designs, and instruments used to monitor the test plots. Wetting tests conducted on the test plots in FY-97 are described and data collected from monitoring the test plots before, during and after the wetting tests are used to evaluate the performance of the covers during FY-97 and FY-98. Replicates of two engineered barrier designs were constructed in the EBTF cells. The first design comprises a thick, vegetated soil cover. The second design incorporates a capillary/biobarrier within the vegtated soil cover. The capillary barrier uses the textural break between an upper, fine textured soil and a lower, coarser-textured gravel layer to inhibit drainage under unsaturated conditions while increasing soil moisture storage in the root zone. Evaporation and transpiration by plants (although the test plots have not yet been vegetated) are used to recycle water stored in the soil back to the atmosphere. A geotextile fabric is used to maintain separation of the soil and gravel layers. A thick layer of cobbles beneath the gravel layer serves as a biobarrier to prevent intrusion of plant roots and burrowing animals into underlying waste (there is no waste in the test plots). Each test plot was instrumented with time domain reflectometry probes and neutron probe access tubes to measure moisture contents, tensiometers, heat dissipation sensors, and thermocouple psychrometers to measure matric potentials, thermocouples to measure soil temperature, and ion-exchange resin beads to monitor tracer movement. Each drainage sump is equipped with a tipping bucket instrument and pressure transducer to measure drainage. Precipitation is measured using a heated rain gauge located at the EBTF. Instrument calibration equation coefficients are presented, and data reduction

  1. Clays in natural and engineered barriers for radioactive waste confinement

    International Nuclear Information System (INIS)

    2007-01-01

    The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO 2 geological sequestration, chemical waste isolation

  2. Clays in natural and engineered barriers for radioactive waste confinement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The meeting covers all topics concerning natural argillaceous geological barriers and the clay material based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties). The works presented deal with: examples of broad research programs (national or international) on the role of natural and artificial clay barriers for radionuclide confinement; clay-based repository concepts: repository designs, including technological and safety issues related to the use of clay for nuclear waste confinement; geology and clay characterisation: mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in rock clay, fracturing, self sealing processes, role of organic matter and microbiological processes; geochemistry: pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry; mass transfer: water status and hydraulic properties in low permeability media, pore space geometry, water, solute and gas transfer processes, colloid mediated transport, large scale movements, long-term diffusion; alteration processes: oxidation effects, hydration-dehydration processes, response to thermal stress, iron-clay interactions, alkaline perturbation; geomechanics: thermo-hydro-mechanical behaviour of clay, rheological models, EDZ characterisation and evolution, coupled behaviour and models (HM, THM, THMC). A particular interest is given to potential contributions coming from fields of activities other than radioactive waste management, which take advantage of the confinement properties of the clay barrier (oil and gas industries, gas geological storage, CO{sub 2} geological sequestration, chemical waste isolation

  3. Improved Barriers to Turbine Engine Fragments: Interim Report II

    National Research Council Canada - National Science Library

    Shockey, Donald

    1999-01-01

    ... the effects of uncontained engine bursts. SRI International is evaluating the ballistic effectiveness of fabric structures made from advanced polymers and developing a computational ability to design fragment barriers...

  4. ENGINEERED BARRIER SYSTEM FEATURES, EVENTS AND PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Jaros, W.

    2005-08-30

    The purpose of this report is to evaluate and document the inclusion or exclusion of engineered barrier system (EBS) features, events, and processes (FEPs) with respect to models and analyses used to support the total system performance assessment for the license application (TSPA-LA). A screening decision, either Included or Excluded, is given for each FEP along with the technical basis for exclusion screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d, e, and f) [DIRS 173273]. The FEPs addressed in this report deal with those features, events, and processes relevant to the EBS focusing mainly on those components and conditions exterior to the waste package and within the rock mass surrounding emplacement drifts. The components of the EBS are the drip shield, waste package, waste form, cladding, emplacement pallet, emplacement drift excavated opening (also referred to as drift opening in this report), and invert. FEPs specific to the waste package, cladding, and drip shield are addressed in separate FEP reports: for example, ''Screening of Features, Events, and Processes in Drip Shield and Waste Package Degradation'' (BSC 2005 [DIRS 174995]), ''Clad Degradation--FEPs Screening Arguments (BSC 2004 [DIRS 170019]), and Waste-Form Features, Events, and Processes'' (BSC 2004 [DIRS 170020]). For included FEPs, this report summarizes the implementation of the FEP in the TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). This report also documents changes to the EBS FEPs list that have occurred since the previous versions of this report. These changes have resulted due to a reevaluation of the FEPs for TSPA-LA as identified in Section 1.2 of this report and described in more detail in Section 6.1.1. This revision addresses updates in Yucca Mountain Project

  5. ENGINEERED BARRIER SYSTEM FEATURES, EVENTS AND PROCESSES

    International Nuclear Information System (INIS)

    Jaros, W.

    2005-01-01

    The purpose of this report is to evaluate and document the inclusion or exclusion of engineered barrier system (EBS) features, events, and processes (FEPs) with respect to models and analyses used to support the total system performance assessment for the license application (TSPA-LA). A screening decision, either Included or Excluded, is given for each FEP along with the technical basis for exclusion screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d, e, and f) [DIRS 173273]. The FEPs addressed in this report deal with those features, events, and processes relevant to the EBS focusing mainly on those components and conditions exterior to the waste package and within the rock mass surrounding emplacement drifts. The components of the EBS are the drip shield, waste package, waste form, cladding, emplacement pallet, emplacement drift excavated opening (also referred to as drift opening in this report), and invert. FEPs specific to the waste package, cladding, and drip shield are addressed in separate FEP reports: for example, ''Screening of Features, Events, and Processes in Drip Shield and Waste Package Degradation'' (BSC 2005 [DIRS 174995]), ''Clad Degradation--FEPs Screening Arguments (BSC 2004 [DIRS 170019]), and Waste-Form Features, Events, and Processes'' (BSC 2004 [DIRS 170020]). For included FEPs, this report summarizes the implementation of the FEP in the TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). This report also documents changes to the EBS FEPs list that have occurred since the previous versions of this report. These changes have resulted due to a reevaluation of the FEPs for TSPA-LA as identified in Section 1.2 of this report and described in more detail in Section 6.1.1. This revision addresses updates in Yucca Mountain Project (YMP) administrative procedures as they

  6. Collaborative engineering experiences

    NARCIS (Netherlands)

    Ir. Peter van Kollenburg; Dr. Ir. P. Mulders; Ir. Dick van Schenk Brill; Dr. Ir. G. Schouten; Dr. J. Ochs

    2000-01-01

    In the fall of 1999, an international integrated product development pilot project based on collaborative engineering was started with team members in two international teams from the United States, The Netherlands and Germany. Team members interacted using various Internet capabilities, including,

  7. Study on vibration behaviors of engineered barrier system

    International Nuclear Information System (INIS)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Minowa, Chikahiro

    1998-01-01

    High-level radioactive wastes have been buried underground by packing into a strong sealed container made from carbon steel (over-pack) with buffer material (bentonite). The engineered barrier system constructed with an overpack and buffer materials must be resistant to earthquakes as well as invasion of groundwater for a long period. Therefore, seismic evaluation of barrier system for earthquakes is indispensable especially in Japan to keep its structural safety. Here, the effects of earthquake vibration on the engineered barrier systems were investigated experimentally. Random-wave vibration and practical seismic wave one were loaded for the systems and fundamental data were obtained. For the former vibration the response characteristics of both engineered barrier models constructed with overpack and bentonite were non-linear. For the latter one, the stress in bentonite was increased in proportion to the vibration level. (M.N.)

  8. University Experiences and Women Engineering Student Persistence

    Science.gov (United States)

    Ayers, LoAnn Debra Gienger

    Riverside University (a pseudonym), like many universities, has not significantly increased the number of women who graduate with bachelor's degrees in engineering. The purpose of the study is to understand how the university experiences of women students influence the decision to persist in an undergraduate engineering degree and to understand the role of self-perception in how the students perceive experiences as supporting or hindering their persistence in the major. Archival data, documents and artifacts, observations, individual interviews, and a focus group with women engineering students provide insights into students' perceived barriers and supports of student success. Analysis of the data results in two major themes. First, students' self-confidence and self-efficacy influence how women assimilate university experiences as either supportive or diminishing of academic success. Second, university policies and practices shape the campus environment within which student experiences are formed and influence a student's level of institutional, academic, and social integration. The results of the study indicate opportunities for university leadership to enhance strategies that positively shape students' institutional, academic and social integration as precursors toward increasing the number of women students who successfully complete undergraduate engineering degrees at Riverside University. Future research is indicated to better understand how gender and gender identity intersects with other demographic factors, such as socio-economic status, immigration status, and life stage (e.g., traditional versus non-traditional students), to support or deter the persistence of engineering students to degree completion.

  9. Engineered barrier systems (EBS): design requirements and constraints

    International Nuclear Information System (INIS)

    2004-01-01

    A joint NEA-EC workshop entitled 'Engineered Barrier Systems: Design Requirements and Constraints' was organised in Turku, Finland on 26-29 August 2003 and hosted by Posiva Oy. The main objectives of the workshop were to promote interaction and collaboration among experts responsible for engineering design and safety assessment in order to develop a greater understanding of how to achieve the integration needed for the successful design of engineered barrier systems, and to clarify the role that an EBS can play in the overall safety case for a repository. These proceedings present the outcomes of this workshop. (author)

  10. Teaching Knowledge Engineering: Experiences

    DEFF Research Database (Denmark)

    Andersen, Tom; Hartvig, Susanne C

    1998-01-01

    Includes description of experiences gained by teaching KE in construction domains. It outlines good starting points and overall guidance to education in applied AI.......Includes description of experiences gained by teaching KE in construction domains. It outlines good starting points and overall guidance to education in applied AI....

  11. Evaluation of synthetic zeolite as engineering passive permeable reactive barrier

    International Nuclear Information System (INIS)

    Ibrahim, O.A.A.

    2011-01-01

    The presence of toxic pollutants in groundwater brings about significant changes in the properties of water resources and has to be avoided in order to preserve the environmental quality. Heavy metals are among the most dangerous inorganic water pollutants, that related to many anthropogenic sources and their compounds are extremely toxic. The treatment of contaminated groundwater is among the most difficult and expensive environmental problems. Over the past years, permeable reactive barriers have provided an increasingly important role in the passive insitu treatment of contaminated groundwater. There are a large number of materials that are able to immobilize contaminants by sorption, including granulated active carbon, zeolite, montmorillonite, peat, compost, sawdust, etc. Zeolite X is a synthetic counterpart of the naturally occurring mineral Faujasite. It has one of the largest cavities and cavity entrances of any known zeolites. The main aim of this work is to examine the possibility of using synthetic zeolite X as an engineering permeable reactive barrier to remove heavy metals from a contaminated groundwater. Within this context, the following investigations were carried out: 1. Review on the materials most commonly used as engineered permeable reactive barriers to identify the important features to be considered in the examination of the proposed permeable reactive barrier material (zeolite X). 2. Synthesis of zeolite X and characterization of the synthesized material using different techniques. 3. Batch tests were carried out to characterize the equilibrium and kinetic sorption properties of the synthesized zeolite X towards the concerned heavy metals; zinc and cadmium ions. 4. Column tests were also performed to determine the design factors for permeable reactive barrier against zinc and cadmium ions solutions.Breakthrough curves measured in such experiments used to determine the hydrodynamic dispersion coefficients for both metal ions. 5. Analytical

  12. CHARACTERIZATION OF BENTONITE FOR ENGINEERED BARRIER SYSTEMS IN RADIOACTIVE WASTE DISPOSAL SITES

    Directory of Open Access Journals (Sweden)

    Dubravko Domitrović

    2012-07-01

    Full Text Available Engineered barrier systems are used in radioactive waste disposal sites in order to provide better protection of humans and the environment from the potential hazards associated with the radioactive waste disposal. The engineered barrier systems usually contain cement or clay (bentonite because of their isolation properties and long term performance. Quality control tests of clays are the same for all engineering barrier systems. Differences may arise in the required criteria to be met due for different application. Prescribed clay properties depend also on the type of host rocks. This article presents radioactive waste management based on best international practice. Standard quality control procedures for bentonite used as a sealing barrier in radioactive waste disposal sites are described as some personal experiences and results of the index tests (free swelling index, water adsorption capacity, plasticity limits and hydraulic permeability of bentonite (the paper is published in Croatian.

  13. TMX-U thermal-barrier experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Barter, J.D.

    1988-01-01

    This review of thermal-barrier experiments in the Tandem Mirror Experiment Upgrade (TMX-U) describes our progress at Lawrence Livermore National Laboratory in plasma confinement and central-cell heating. Thermal barriers in TMX-U improved axial confinement by two orders of magnitude over a limited range of densities, compared with confinement in single-cell mirrors at the same ion temperature. Our study shows that central-cell radial nonambipolar confinement scales as neoclassical theory and can be eliminated by floating the end walls. Radial ambipolar losses can also be measured and reduced. The electron energy balance is improved in tandem mirrors to near classical, resulting in T/sub e/ up to 0.28 keV. Electron cyclotron heating (ECH) efficiencies up to 42 percent, with low levels of electron microinstability, were achieved when hot electrons in the thermal barrier were heated to average betas as large as 15 percent. The hot-electron distribution is measured from X rays and is modeled by a Fokker-Planck code that includes heating from cavity radio-frequency (RF) fields. Neutral-beam injection in the central cell created average ion betas up to 5 percent with radial profiles of hot ions that are modeled accurately by a radial Fokker-Planck code. Gas fueling between two fundamental ion cyclotron heating (ICH) resonances resulted in symmetrical heating of passing ions toward both ends

  14. PVD TBC experience on GE aircraft engines

    Science.gov (United States)

    Maricocchi, Antonio; Bartz, Andi; Wortman, David

    1995-01-01

    The higher performance levels of modern gas turbine engines present significant challenges in the reliability of materials in the turbine. The increased engine temperatures required to achieve the higher performance levels reduce the strength of the materials used in the turbine sections of the engine. Various forms of thermal barrier coatings (TBC's) have been used for many years to increase the reliability of gas turbine engine components. Recent experience with the physical vapor deposition (PVD) process using ceramic material has demonstrated success in extending the service life of turbine blades and nozzles. Engine test results of turbine components with a 125 micron (0.005 in) PVD TBC have demonstrated component operating temperatures of 56-83 C (100-150 F) lower than non-PVD TBC components. Engine testing has also revealed the TBC is susceptible to high angle particle impact damage. Sand particles and other engine debris impact the TBC surface at the leading edge of airfoils and fracture the PVD columns. As the impacting continues, the TBC erodes away in local areas. Analysis of the eroded areas has shown a slight increase in temperature over a fully coated area, however a significant temperature reduction was realized over an airfoil without TBC.

  15. FACTORS AFFECTING PERFORMANCE OF ENGINEERED BARRIERS

    International Nuclear Information System (INIS)

    J.A. BLINK, R.W. ANDREWS, J.N. BAILEY, T.W. DOERING J.H. LEE, J.K. MCCOY, D.G. MCKENZIE, D. SEVOUGIAN AND V. VALLIKAT

    1998-01-01

    For the Yucca Mountain Viability Assessment (VA), a reference design was tentatively selected in September 1997, and a series of model abstractions are being prepared for the performance assessment (PA) of that design. To determine the sensitivity of peak dose rate at the accessible environment to engineered components, several design options were subjected to the PA models available late in FY97

  16. Aerospace engineering training: universities experience

    Directory of Open Access Journals (Sweden)

    Mertins Kseniya

    2016-01-01

    Full Text Available Contemporary professional working in aerospace engineering must have a set of soft and hard skills. The experience gained in universities shows that training of a competent professional is impossible without an employer involved in this process. The paper provides an analysis of missions, tasks and experience of aerospace professionals and identifies the present and future roles, missions and required skills of a highly qualified specialist in aerospace engineering. This analysis can be used to design a master’s program aiming at providing students with the required knowledge, know-how and attitudes needed to succeed as professionals in industrial companies.

  17. Alternative approaches to reliability modeling of a multiple engineered barrier system

    International Nuclear Information System (INIS)

    Ananda, M.M.A.; Singh, A.K.

    1994-01-01

    The lifetime of the engineered barrier system used for containment of high-level radioactive waste will significantly impact the total performance of a geological repository facility. Currently two types of designs are under consideration for an engineered barrier system, single engineered barrier system and multiple engineered barrier system. Multiple engineered barrier system consists of several metal barriers and the waste form (cladding). Some recent work show that a significant improvement of performance can be achieved by utilizing multiple engineered barrier systems. Considering sequential failures for each barrier, we model the reliability of the multiple engineered barrier system. Weibull and exponential lifetime distributions are used through out the analysis. Furthermore, the number of failed engineered barrier systems in a repository at a given time is modeled using a poisson approximation

  18. Performance of engineered barriers for low-level waste

    International Nuclear Information System (INIS)

    Taplin, D.; Claridge, F.B.

    1987-09-01

    Geotechnical Resources Ltd., in association with Komex Consultants Ltd., was retained to collect, synthesize and evaluate the available information on the long term performance of engineered barriers for low-level radioactive wastes disposed in Canada. Literature was researched from Canadian, United States and European sources. A variety of barrier materials were assessed in the study and included natural clays, concrete and cement, metals, bentonite-sand admixes, bitumen and bituminous admixes, soil cement and polymeric membranes. The generalized geological and geotechnical conditions encountered within the soil and rock host media currently under consideration for disposal sites in southern Ontario were also summarized. Both internal barriers, or buffers, to immobilize the waste material and reduce radionuclide mobility, as well as external barriers to limit the migration of contaminants were examined. Microbial activities within the waste forms were analyzed, including cellulose degradation, methanogenesis and bicarbonate and organic reactions. Microbial interactions with the various engineered barrier materials under consideration were also assessed. Finally, the anticipated long term performances of the respective barrier materials under consideration were evaluated, along with the general suitability of the geological host media being proposed for disposal sites

  19. The role of engineered barriers in spent fuel disposal

    International Nuclear Information System (INIS)

    Vokal, A.

    1997-01-01

    Engineered, i.e. man-made, barriers in underground spent fuel disposal include the waste form itself, the fuel cladding, the storage container, and the isolating system made of buffering, filling, and sealing materials. The parameters of and requirements for each of the components are highlighted, and the methodology of materials selection is discussed. (P.A.)

  20. Engineered Barrier System: Physical and Chemical Environment Model

    International Nuclear Information System (INIS)

    Jolley, D. M.; Jarek, R.; Mariner, P.

    2004-01-01

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

  1. Natural analogue study on engineered barriers for underground disposal of radioactive wastes

    International Nuclear Information System (INIS)

    Araki, K.; Motegi, M.; Emoto, Y.; Kaji, Y.; Ikari, S.; Nada, T.; Watanabe, T.

    1989-01-01

    This is a report to develop the natural analogue methodology for the assessment of the life of the engineered barriers beyond the time period of normal experiments, 1000 years, for the disposal of low-level radioactive wastes with activity levels greater than those of wastes acceptable for shallow land burial in Japan. Geological and archeological events and objects available for the assessment of the possible life of each engineered barrier are surveyed. Taking heavy precipitation into account in Japan, a long-term, zero-release engineered barrier system using long-term durable materials based on the natural analogue events and objects is proposed along with the conventional type of water permeable engineered barrier system. The combination of the material quality and the environment that could be achieved within the repository is important for the long-term durability of the engineered barrier material. It is proposed that for the natural analogue study a physico-chemical methodology, which may be referred to as the physico-chemical natural history, is necessary to get parameters from the natural analogue events for the long-term assessment of the disposal system

  2. Removing bridge barriers stimulates suicides: an unfortunate natural experiment.

    Science.gov (United States)

    Beautrais, Annette L; Gibb, Sheree J; Fergusson, David M; Horwood, L John; Larkin, Gregory Luke

    2009-06-01

    Safety barriers to prevent suicide by jumping were removed from Grafton Bridge in Auckland, New Zealand, in 1996 after having been in place for 60 years. This study compared the number of suicides due to jumping from the bridge after the reinstallation of safety barriers in 2003. National mortality data for suicide deaths were compared for three time periods: 1991-1995 (old barrier in place); 1997-2002 (no barriers in place); 2003-2006 (after barriers were reinstated). Removal of barriers was followed by a fivefold increase in the number and rate of suicides from the bridge. These increases led to a decision to reinstall safety barriers. Since the reinstallation of barriers, of an improved design, in 2003, there have been no suicides from the bridge. This natural experiment, using a powerful a-b-a (reversal) design, shows that safety barriers are effective in preventing suicide: their removal increases suicides; their reinstatement prevents suicides.

  3. Review of durability of cementitious engineered barriers in repository environments

    International Nuclear Information System (INIS)

    Parrott, L.J.; Lawrence, C.D.

    1992-01-01

    This report is concerned with the durability of cementitious engineered barriers in a repository for low and intermediate level nuclear waste. Following the introduction the second section of the review identifies the environmental conditions associated with a deep, hard rock repository for ILW and LLW that are relevant to the durability of cementitious barriers. Section three examines the microstructure and macrostructure of cementitious materials and considers the physical and chemical processes of radionuclide immobilization. Potential repository applications and compositions of cementitious materials are reviewed in Section four. The main analysis of durability is dealt with in Section five. The different types of cementitious barrier are considered separately and their most probable modes of degradation are analysed. Concluding remarks that highlight critical technical matters are given in Section six. (author)

  4. Integrated modelling of near field and engineered barrier system processes

    International Nuclear Information System (INIS)

    Lamont, A.; Gansemer, J.

    1994-01-01

    The Yucca Mountain Integrating Model (YMIM) is an integrated model of the Engineered barrier System has been developed to assist project managers at LLNL in identifying areas where research emphasis should be placed. The model was designed to be highly modular so that a model of an individual process could be easily modified or replaced without interfering with the models of other processes. The modules modelling container failure and the dissolution of nuclides include particularly detailed, temperature dependent models of their corresponding processes

  5. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    Energy Technology Data Exchange (ETDEWEB)

    E.L. Hardin

    2000-07-17

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II).

  6. Engineered Barrier System: Physical and Chemical Environment Model

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Jolley; R. Jarek; P. Mariner

    2004-02-09

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  7. Engineered Barrier System Degradation, Flow, and Transport Process Model Report

    International Nuclear Information System (INIS)

    E.L. Hardin

    2000-01-01

    The Engineered Barrier System Degradation, Flow, and Transport Process Model Report (EBS PMR) is one of nine PMRs supporting the Total System Performance Assessment (TSPA) being developed by the Yucca Mountain Project for the Site Recommendation Report (SRR). The EBS PMR summarizes the development and abstraction of models for processes that govern the evolution of conditions within the emplacement drifts of a potential high-level nuclear waste repository at Yucca Mountain, Nye County, Nevada. Details of these individual models are documented in 23 supporting Analysis/Model Reports (AMRs). Nineteen of these AMRs are for process models, and the remaining 4 describe the abstraction of results for application in TSPA. The process models themselves cluster around four major topics: ''Water Distribution and Removal Model, Physical and Chemical Environment Model, Radionuclide Transport Model, and Multiscale Thermohydrologic Model''. One AMR (Engineered Barrier System-Features, Events, and Processes/Degradation Modes Analysis) summarizes the formal screening analysis used to select the Features, Events, and Processes (FEPs) included in TSPA and those excluded from further consideration. Performance of a potential Yucca Mountain high-level radioactive waste repository depends on both the natural barrier system (NBS) and the engineered barrier system (EBS) and on their interactions. Although the waste packages are generally considered as components of the EBS, the EBS as defined in the EBS PMR includes all engineered components outside the waste packages. The principal function of the EBS is to complement the geologic system in limiting the amount of water contacting nuclear waste. A number of alternatives were considered by the Project for different EBS designs that could provide better performance than the design analyzed for the Viability Assessment. The design concept selected was Enhanced Design Alternative II (EDA II)

  8. JET internal transport barriers: experiment vs theory

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, B [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Crisanti, F [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Parail, V [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Maget, P [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Baranov, Y [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Becoulet, A [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Castaldo, C [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Challis, C D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Angelis, R De [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Garbet, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Giroud, C [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Hawkes, N [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Joffrin, E [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Litaudon, X [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Mazon, D [Association Euratom - CEA pour la Fusion, CEA Cadarache, F-13108 Saint Paul-lez-Durance Cedex (France); Riva, M [Associazione Euratom - ENEA sulla Fusione, C.R. Frascati, CP 65, I-00040, Frascati, Rome (Italy); Zastrow, K D [Euratom/UKAEA Fusion Association, Cuhlam Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2003-06-01

    A large variety of JET discharges with internal transport barriers (ITBs) has been analysed in order to determine the main features which characterize turbulence stabilization at the barrier. It is found that the location of barriers is well correlated with regions where the ExB flow shearing rate exceeds the linear growth rate of the ion temperature gradient mode instability ({gamma}{sub {eta}{sub i}}). A key point is the dependence of {gamma}{sub {eta}{sub i}} on the magnetic shear: in the discharges of this database the reduction of {gamma}{sub {eta}{sub i}} associated to very low or null magnetic shear favours the formation of an ITB. After the ITB formation a positive feedback occurs in which the ExB flow shear mechanism has the leading role and the position of the barrier may be no longer linked to the low shear region.

  9. Chemical interaction of tetravalent actinides simulators and the engineering barrier

    International Nuclear Information System (INIS)

    Chain, Pablo; Alba, Maria D.; Castro, Miguel A.; Pavon, Esperanza; Mar Orta, M.

    2010-01-01

    Document available in extended abstract form only. The Deep Geological Repository (DGR) is the most internationally accepted option for the storage of high radioactive wastes. This confinement is based on the Multi-barrier Concept where the engineered barrier is a crucial safety wise. Nowadays, bentonite is accepted as the best argillaceous material in the engineered barrier of DGR. Additionally to its well-known physical role, a chemical interaction between lutetium, as actinide simulator, and the smectite has been demonstrated. The existence of a reaction mechanism, which was not previously described, based on the chemical interaction between the lanthanide cations and the orthosilicate anions of the lamellar structure has been identified. This finding has aroused the interest of the scientific community because lanthanides are used as simulators of high activity radionuclide (HAR) in agreement with the guidelines established in the bibliography. It has been observed that in conditions of moderate temperature and pressure a chemical interaction exists between smectites and rare earth elements (RE) and phases of insoluble di-silicate, RE 2 Si 2 O 7 , which would immobilize RE, are generated. It is remarkable that the reaction extends to all the set of the smectites, although they do not display the same reactivity, the saponite being the most reactive. The main isotopes present in the HLW belong to the actinide elements Np, Pu, Am and Cm, in addition to uranium generated by neutron capture during the fuel combustion process. The study of the mobilization of actinide (IV) thorough the bentonite barrier is limited because of their radioactivity. However, U(IV), Np(IV), Pu(IV) and Th(IV) can be simulated by the stable isotopes of the Zr(IV) and Hf(IV), because they exhibit ionic radius and physicochemical properties very similar to those of the actinide elements. It is the main objective of this research to investigate the chemical interaction of Zr(IV) as actinide

  10. Engineered sorbent barriers for low-level waste disposal

    International Nuclear Information System (INIS)

    Mitchell, S.J.; Freeman, H.D.; Buelt, J.L.

    1987-01-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is developing sorbent materials to prevent the migration of radionuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Screening studies identified promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite of clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent, adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 2 references, 6 figures, 3 tables

  11. Engineered sorbent barriers for low-level waste disposal.

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Mitchell, S.J.; Buelt, J.L.

    1986-12-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is investigating sorbent materials to prevent the migration of soluble radio nuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Laboratory studies identifield promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent and was adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and local soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow-land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 7 refs., 14 figs., 12 tabs.

  12. Engineered sorbent barriers for low-level waste disposal

    International Nuclear Information System (INIS)

    Freeman, H.D.; Mitchell, S.J.; Buelt, J.L.

    1986-12-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is investigating sorbent materials to prevent the migration of soluble radio nuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Laboratory studies identifield promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent and was adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and local soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow-land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 7 refs., 14 figs., 12 tabs

  13. PILOT-SCALE EVALUATION OF ENGINEERED BARRIER SYSTEMS FOR THE YUCCA MOUNTAIN PROJECT

    International Nuclear Information System (INIS)

    Webb, S.W.; George, J.T.; Finley, R.E.

    2001-01-01

    This paper describes two quarter-scale experiments (1.4 m diameter) and associated numerical analyses on granular backfill engineered barrier systems in support of the Yucca Mountain Project for the potential repository. The two configurations include a sloped capillary barrier and a plain backfill. The tests involve application of dyed water as a constant line infiltration source along the top of the test set-up, monitoring water movement through the test, and measuring water exiting the experiments. A complete water balance estimate is made for each test, and observed water movement is compared with (1) detailed numerical analyses conducted using the TOUGH2 code for unsaturated flow in porous media and (2) posttest observations. The results of the testing and analyses show that for the injection rates and configuration applied, the capillary barrier design diverts a significant amount of all injected water and the TOUGH2 pretest predictions show qualitative and quantitative agreement with the experimental data

  14. Engineering Sustainable Engineers through the Undergraduate Experience

    Science.gov (United States)

    Weatherton, Yvette Pearson; Sattler, Melanie; Mattingly, Stephen; Chen, Victoria; Rogers, Jamie; Dennis, Brian

    2012-01-01

    In order to meet the challenges of sustainable development, our approach to education must be modified to equip students to evaluate alternatives and devise solutions that meet multi-faceted requirements. In 2009, faculty in the Departments of Civil, Industrial and Mechanical Engineering at the University of Texas at Arlington began implementation…

  15. Materials characterization center workshop on corrosion of engineered barriers

    Energy Technology Data Exchange (ETDEWEB)

    Merz, M.D.; Zima, G.E.; Jones, R.H.; Westerman, R.E.

    1981-03-01

    A workshop on corrosion test procedures for materials to be used as barriers in nuclear waste repositories was conducted August 19 and 20, 1980, at the Battelle Seattle Research Center. The purpose of the meeting was to obtain guidance for the Materials Characterization Center in preparing test procedures to be approved by the Materials Review Board. The workshop identified test procedures that address failure modes of uniform corrosion, pitting and crevice corrosion, stress corrosion, and hydrogen effects that can cause delayed failures. The principal areas that will require further consideration beyond current engineering practices involve the analyses of pitting, crevice corrosion, and stress corrosion, especially with respect to quantitative predictions of the lifetime of barriers. Special techniques involving accelerated corrosion testing for uniform attack will require development.

  16. Yucca Mountain engineered barrier system corrosion model (EBSCOM)

    International Nuclear Information System (INIS)

    King, F.; Kolar, M.; Kessler, J.H.; Apted, M.

    2008-01-01

    A revised engineered barrier system model has been developed by the Electric Power Research Institute to predict the time dependence of the failure of the drip shields and waste packages in the proposed Yucca Mountain repository. The revised model is based on new information on various corrosion processes developed by the US Department of Energy and others and for a 20-mm-thick waste package design with a double closure lid system. As with earlier versions of the corrosion model, the new EBSCOM code produces a best-estimate of the failure times of the various barriers. The model predicts that only 15% of waste packages will fail within a period of 1 million years. The times for the first corrosion failures are 40,000 years, 336,000 years, and 375,000 years for the drip shield, waste package, and combination of drip shield and the associated waste package, respectively

  17. Materials characterization center workshop on corrosion of engineered barriers

    International Nuclear Information System (INIS)

    Merz, M.D.; Zima, G.E.; Jones, R.H.; Westerman, R.E.

    1981-03-01

    A workshop on corrosion test procedures for materials to be used as barriers in nuclear waste repositories was conducted August 19 and 20, 1980, at the Battelle Seattle Research Center. The purpose of the meeting was to obtain guidance for the Materials Characterization Center in preparing test procedures to be approved by the Materials Review Board. The workshop identified test procedures that address failure modes of uniform corrosion, pitting and crevice corrosion, stress corrosion, and hydrogen effects that can cause delayed failures. The principal areas that will require further consideration beyond current engineering practices involve the analyses of pitting, crevice corrosion, and stress corrosion, especially with respect to quantitative predictions of the lifetime of barriers. Special techniques involving accelerated corrosion testing for uniform attack will require development

  18. Study on vibration behaviors of engineered barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Mikoshiba, Tadashi; Ogawa, Nobuyuki; Minowa, Chikahiro [National Research Inst. for Earth Science and Disaster Prevention, Tsukuba, Ibaraki (Japan)

    1999-02-01

    Small engineered barrier model was mode and tested by vibrating with the random wave and the real earthquake wave. The wave observed at Kamaishi (N-S, N-W), Iwate Prefecture, in September 6, 1993, and Kobe (N-S) etc. were used as the real earthquake waves. The trial overpack showed non-linear characteristics (soft spring) by vibrating with the random wave. The pressure and acceleration of trial overpack and constraint container increased with increasing the vibration level of the real earthquake wave. The trial overpack moved the maximum 1.7 mm of displacement and 16 mm subsidence. The results showed both waves rocked the trialpack. (S.Y.)

  19. Scientific investigation plan for initial engineered barrier system field tests

    International Nuclear Information System (INIS)

    Wunan Lin.

    1993-02-01

    The purpose of this Scientific Investigation Plan (SIP) is to describe tests known as Initial Engineered Barrier System Field Tests (IEBSFT) and identified by Work Breakdown Structure as WBS 1.2.2.2.4. The IEBSFT are precursors to the Engineered Barrier System Field Test (EBSFT), WBS 1.2.2.2.4, to be conducted in the Exploratory Study Facility (ESF) at Yucca Mountain. The EBSFT and IEBSFT are designed to provide information on the interaction between waste packages (simulated by heated containers) and the surrounding rock mass, its vadose water, and infiltrated water. Heater assemblies will be installed in drifts or boreholes openings and heated to measure moisture movement during heat-up and subsequent cool-down of the rock mass. In some of the tests, infiltration of water into the heated rock mass will be studied. Throughout the heating and cooling cycle, instruments installed in the rock will monitor such parameters as temperature, moisture content, concentration of some chemical species, and stress and strain. Rock permeability measurements, rock and fluid (water and gas) sampling, and fracture pattern measurements will also be made before and after the test

  20. The disposal of Canada's nuclear fuel waste: engineered barriers alternatives

    International Nuclear Information System (INIS)

    Johnson, L.H.; Tait, J.C.; Shoesmith, D.W.; Crosthwaite, J.L.; Gray, M.N.

    1994-01-01

    The concept for disposal of Canada's nuclear fuel waste involves emplacing the waste in a vault excavated at a depth of 500 to 1000 m in plutonic rock of the Canadian Shield. The solid waste would be isolated from the biosphere by a multibarrier system consisting of engineered barriers, including long-lived containers and clay and cement-based sealing materials, and the natural barrier provided by the massive geological formation. The technical feasibility of this concept and its impact on the environment and human health are being documented in an Environmental Impact Statement (EIS), which will be submitted for review under the federal Environmental Assessment and Review Process. This report, one of nine EIS primary references, describes the various alternative designs and materials for engineered barriers that have been considered during the development of the Canadian disposal concept and summarizes engineered barrier concepts being evaluated in other countries. The basis for the selection of a reference engineered barrier system for the EIS is presented. This reference system involves placing used CANDU (Canada Deuterium Uranium) fuel bundles in titanium containers, which would then be emplaced in boreholes drilled in the floor of disposal rooms. Clay-based sealing materials would be used to fill both the space between the containers and the rock and the remaining excavations. In the section on waste forms, the properties of both used-fuel bundles and solidified high-level wastes, which would be produced by treating wastes resulting from the reprocessing of used fuel, are discussed. Methods of solidifying the wastes and the chemical durability of the solidified waste under disposal conditions are reviewed. Various alternative container designs are reviewed, ranging from preliminary conceptual designs to designs that have received extensive prototype testing. Results of structural performance, welding and inspection studies are also summarized. The corrosion of

  1. Study on the saturating and swelling behavior of an engineering bentonite barrier using a test model

    International Nuclear Information System (INIS)

    Nakajima, Makoto; Kobayashi, Ichizo; Toida, Masaru; Fujisaki, Katsutoshi

    2007-01-01

    The conceptual design of a disposal facility with additional buffer depth for radioactive waste is mainly constituted from the multi-barrier system that is constructed around the waste form so that it prevents radionuclide transfer to the biosphere. The engineered bentonite barrier is one of the elements of the multi-barrier system and is constructed with homogeneous bentonite-containing material compacted to a high density so that there are no voids. Due to the swelling characteristics of the bentonite material, the self-sealing function which is an important function of the bentonite barrier can work, but at the same time it mechanically affects the neighboring structures. Therefore, an experimental study was implemented in order to evaluate the mechanical effect of the bentonite swelling behavior throughout the construction, emplacement operations and closure re-saturation phase. In this article, the results of swelling tests to obtain the mechanical properties of the bentonite and three types of test model experiments performed for the event observations in the different saturation processes are described. As a result, the effects of a seepage pattern of ground water and a variation in the density produced by construction on the swelling pressure distribution of the bentonite barrier could be reproduced and validated. It is thought that they will be important events when ground water permeates the bentonite layer of a multiple barrier system. (author)

  2. Recent results from TMX-U thermal barrier experiments

    International Nuclear Information System (INIS)

    Molvik, A.W.; Allen, S.; Barter, J.

    1984-01-01

    The Tandem Mirror Experiment-Upgrade (TMX-U) device was designed to study plasma confinement in a tandem mirror with thermal barriers. Previously the author reported improved axial confinement with high end-plug potentials, consistent with thermal barrier operation. Now, the existence of thermal barriers in TMX-U confirmed by measuring the axial potential profile. Specifically, measured the change in energy of a 5-keV deuterium neutral beam that is injected nearly parallel to the axis and is ionized between the barrier and the central cell. The authors found that the barrier potential is lower than the central cell potential, as required for a thermal barrier. The peak potential is at least 2.4 keV, as determined from the minimum energy of end loss ions. In addition, radial transport is reduced by the use of floating and electrodes that map to concentric cylinders in the central cell. Sloshing ions continue to be microstable

  3. Barriers and paths to market for genetically engineered crops.

    Science.gov (United States)

    Rommens, Caius M

    2010-02-01

    Each year, billions of dollars are invested in efforts to improve crops through genetic engineering (GE). These activities have resulted in a surge of publications and patents on technologies and genes: a momentum in basic research that, unfortunately, is not sustained throughout the subsequent phases of product development. After more than two decades of intensive research, the market for transgenic crops is still dominated by applications of just a handful of methods and genes. This discrepancy between research and development reflects difficulties in understanding and overcoming seven main barriers-to-entry: (1) trait efficacy in the field, (2) critical product concepts, (3) freedom-to-operate, (4) industry support, (5) identity preservation and stewardship, (6) regulatory approval and (7) retail and consumer acceptance. In this review, I describe the various roadblocks to market for transgenic crops and also discuss methods and approaches on how to overcome these, especially in the United States.

  4. Barriers to the clinical translation of orthopedic tissue engineering.

    Science.gov (United States)

    Evans, Christopher H

    2011-12-01

    Tissue engineering and regenerative medicine have been the subject of increasingly intensive research for over 20 years, and there is concern in some quarters over the lack of clinically useful products despite the large sums of money invested. This review provides one perspective on orthopedic applications from a biologist working in academia. It is suggested that the delay in clinical application is not atypical of new, biologically based technologies. Some barriers to progress are acknowledged and discussed, but it is also noted that preclinical studies have identified several promising types of cells, scaffolds, and morphogenetic signals, which, although not optimal, are worth advancing toward human trials to establish a bridgehead in the clinic. Although this transitional technology will be replaced by more sophisticated, subsequent systems, it will perform valuable pioneering functions and facilitate the clinical development of the field. Some strategies for achieving this are suggested. © Mary Ann Liebert, Inc.

  5. Clay-based materials for engineered barriers: a review

    International Nuclear Information System (INIS)

    Lajudie, A.; Raynal, J.; Petit, J.C.; Toulhoat, P.

    1994-01-01

    The potential importance of backfilling and plugging in underground radioactive waste repositories has led different research institutions to carry out extensive studies of swelling clay materials for the development of engineered barriers in underground conditions. These materials should combine a variety of hydro-thermo-mechanical and geochemical properties: impermeability, swelling ability in order to fill all void space, heat transfer and retention capacity for the most noxious radionuclides. Smectite clays best exhibit these properties and most of the research effort has been devoted to this type of materials. In this paper, mineralogical composition, sodium or calcium content, thermo-hydro-mechanical properties, swelling pressure, hydraulic and thermal conductivity, and chemical properties of five smectite clays selected by five major nuclear countries are reviewed: Avonseal montmorillonite (Canada), MX 80 montmorillonite (Sweden), Montigel montmorillonite (Switzerland), S-2 montmorillonite (Spain), and Fo-Ca inter stratified kaolinite/beidellite (France). (J.S.). 29 refs., 5 figs., 3 tabs

  6. PEBS. Long-term performance of engineered barrier systems

    Energy Technology Data Exchange (ETDEWEB)

    Wieczorek, Klaus; Czaikowski, Oliver; Miehe, Ruediger

    2014-12-15

    The evolution of the engineered barrier system (EBS) of geological repositories for radioactive waste has been the subject of many national and international research programmes. The emphasis of the research activities was on the elaboration of a detailed understanding of the complex THMC processes, which are expected to evolve in the early post closure period in the near field. From the perspective of radiological long-term safety, an in-depth understanding of these coupled processes is of great significance, because the evolution of the EBS during the early post-closure phase may have a non-negligible impact on the radiological safety functions at the time when the canisters breach. Unexpected process interactions during the resaturation phase could impair the safety-relevant parameters in the EBS (e. g. swelling pressure, hydraulic conductivity, diffusivity).

  7. Bentonite engineered barrier building method for radioactive waste on sub-surface disposal test project

    International Nuclear Information System (INIS)

    Mori, Takuo; Takahashi, Shinichi; Takeuchi, Kunifumi; Namiki, Kazuto

    2008-01-01

    The engineering barriers such as clay and concrete materials are planned to use for covering radioactive waste in cavern-type disposal facility. The requirement to clay barrier is very low permeability, which could be satisfied by high density Bentonite, and such a compaction method will be needed. Two methods, compaction and air shot, were tested in engineering scale for constructing a high-density clay barrier. Two types of compaction equipments, 'Teasel plate' and 'Plate compacter', were developed and engineering scale experiments were performed for compacting Bentonite only and Bentonite-sand-aggregate mixture. As a result, the Teasel plate can reach higher density Bentonite in relatively short time in comparison to other equipments. While, regarding air shot method, an air-shot machine in a tunnel construction site was tested by different water adding methods (wet, dry, and half wet). It is concluded that the dry and half wet constructing methods will achieve reasonable workability. As a result, the best construction option can be chosen according to the locations of radioactive waste facility. (author)

  8. Engineered barrier durability: An issue for disposal near populated areas

    International Nuclear Information System (INIS)

    Porter, C.L.

    1995-01-01

    Under the current national policy for disposal of low-level radioactive waste (LLW) in the United States of America, each State is required to provide disposal capacity for the LLW generated within its borders. The formation of ''Compacts'' of several States is allowed if approved by Congress. Such forced regionalization of disposal facilities based on State boundaries results in some disposal facilities being sited near populated areas at locations with less than optimum site characteristics from a disposal standpoint. To compensate for this engineered barriers are included in the proposed designs. Portland cement based concrete (PCC), which is the dominant material for disposal vault designs, is degraded via many mechanisms, most of which are related to its permeability. The numerous uncertainties associated with the long-term performance of PCC has lead to many unsuccessful attempts to obtain public acceptance of proposed disposal facilities. These unsuccessful efforts have delayed establishing disposal capacity to the point that a crisis is looming on the horizon. This paper investigates the results of on-going research into the viability of commercially available, impermeable, mass-poured construction materials as an alternative to PCC in LLW disposal vaults. The results from testing and research on two such materials, concrete made from sulfur polymer cement (SPC) and ICOM (an epoxy based concrete) are reported. Material properties and test results include strength parameters, chemical resistance, porosity, permeability, deconability, radiation damage resistance, and biodegradation. The data indicates that with these alternative materials the uncertainties in predicting service life of an engineered barrier can be reduced

  9. Development of the Canadian used fuel repository engineered barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Hatton, C., E-mail: chatton@nwmo.ca [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2015-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for the safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. In implementing APM, the NWMO is committed to ensure consistency with international best practices in the development of its repository system, including any advances in technology. In 2012, the NWMO undertook an optimization study to look at both the design and manufacture of its engineered barriers. This study looked at current technologies for the design and manufacture of used fuel containers, placement technologies, repository design, and buffer and sealing systems, while taking into consideration the state of the art worldwide in repository design and acceptance. The result of that study is the current Canadian engineered barrier system, consisting of a 2.7 tonne used fuel container with a carbon-steel core, copper-coated surface and welded spherical heads. The used fuel container is encapsulated in a bentonite buffer box at the surface and then transferred underground. Once underground, the used fuel is placed into a repository room which is cut into the rock using traditional drill-and-blast technologies. This paper explains the logic for the selection of the container and sealing system design and the development of innovative technologies for their manufacture including the use of laser welding, cold spray and pulsed-electrodeposition copper coating for the manufacture of the used fuel container, isostatic presses for the production of the one-piece bentonite blocks, and slip-skid technologies for placement into the repository. (author)

  10. Development of the Canadian used fuel repository engineered barrier system

    International Nuclear Information System (INIS)

    Hatton, C.

    2015-01-01

    The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for the safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. In implementing APM, the NWMO is committed to ensure consistency with international best practices in the development of its repository system, including any advances in technology. In 2012, the NWMO undertook an optimization study to look at both the design and manufacture of its engineered barriers. This study looked at current technologies for the design and manufacture of used fuel containers, placement technologies, repository design, and buffer and sealing systems, while taking into consideration the state of the art worldwide in repository design and acceptance. The result of that study is the current Canadian engineered barrier system, consisting of a 2.7 tonne used fuel container with a carbon-steel core, copper-coated surface and welded spherical heads. The used fuel container is encapsulated in a bentonite buffer box at the surface and then transferred underground. Once underground, the used fuel is placed into a repository room which is cut into the rock using traditional drill-and-blast technologies. This paper explains the logic for the selection of the container and sealing system design and the development of innovative technologies for their manufacture including the use of laser welding, cold spray and pulsed-electrodeposition copper coating for the manufacture of the used fuel container, isostatic presses for the production of the one-piece bentonite blocks, and slip-skid technologies for placement into the repository. (author)

  11. Engineered sorbent barriers for low-level waste disposal

    International Nuclear Information System (INIS)

    Mitchell, S.J.; Freeman, H.D.; Buelt, J.L.

    1986-01-01

    Pacific Northwest Laboratory is developing sorbent materials to prevent the migration of radionuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Screening studies identified promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent, adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt %), activated charcoal (6 wt %), synthetic zeolite (20 wt %), and soil (73 wt %) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 2 refs., 6 figs., 3 tabs

  12. Evaluation of engineered barriers at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Bhatt, R.N.; Porro, I.

    1998-03-01

    Subsurface Disposal (SDA) of the Radioactive Waste Management Complex serves as the low level waste burial ground at the Idaho National Engineering and Environmental Laboratory (INEEL). The low level wastes are buried in trenches, pits, and soil vaults in surficial sediments. A closure/post-closure plan must be written prior to closure of the SDA. The closure plan for the facility must include a design for an engineered barrier closure cover that will meet all applicable regulatory requirements. This paper describes the approach being followed at the INEEL to choose an appropriate cover design for the SDA closure. Regulatory requirements and performance objectives potentially applicable to closure of the SDA were identified. Technical issues related to SDA closure were identified from a literature search of previous arid site engineered barrier studies and from previous SDA closure cover evaluations. Five engineered barrier conceptual design alternatives were identified: (1) a bio/capillary barrier cover, (2) a thin soil cover, (3) a thick soil cover, (4) a Resource Conservation and Recovery Act cover, and (5) a concrete sealed surface cover. Two of these designs were chosen for in situ hydraulic testing, rather than all five, in order to maximize the amount of information generated relative to projected project costs. Testing of these two cover designs provides data to quantify hydrologic model input parameters and for verification of site specific hydrologic models for long term closure cover performance evaluation and detailed analysis of closure cover alternatives. The specific objectives of the field tests are to determine the water balance for the two covers over several years and to determine cover soil physical and hydraulic properties

  13. Infusing Real World Experiences into Engineering Education

    Science.gov (United States)

    National Academies Press, 2012

    2012-01-01

    The aim of this report is to encourage enhanced richness and relevance of the undergraduate engineering education experience, and thus produce better-prepared and more globally competitive graduates, by providing practical guidance for incorporating real world experience in US engineering programs. The report, a collaborative effort of the…

  14. Design of experiments in production engineering

    CERN Document Server

    2016-01-01

    This book covers design of experiments (DoE) applied in production engineering as a combination of manufacturing technology with applied management science. It presents recent research advances and applications of design experiments in production engineering and the chapters cover metal cutting tools, soft computing for modelling and optmization of machining, waterjet machining of high performance ceramics, among others.

  15. Combined Effects of JP-8 Fuel and Ceramic Thermal Barrier Coatings on the Performance and Emissions of a DI Diesel Engine

    National Research Council Canada - National Science Library

    Klett, David

    1999-01-01

    .... The experiments were conducted on a Ricardo Hydra single-cylinder DI diesel engine. Thin ceramic thermal barrier coatings were applied to various combustion chamber surfaces including the piston crown, cylinder head, and cylinder liner...

  16. Engineered Barrier System performance requirements systems study report. Revision 02

    Energy Technology Data Exchange (ETDEWEB)

    Balady, M.A.

    1997-01-14

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken.

  17. Engineered Barrier System performance requirements systems study report. Revision 02

    International Nuclear Information System (INIS)

    Balady, M.A.

    1997-01-01

    This study evaluates the current design concept for the Engineered Barrier System (EBS), in concert with the current understanding of the geologic setting to assess whether enhancements to the required performance of the EBS are necessary. The performance assessment calculations are performed by coupling the EBS with the geologic setting based on the models (some of which were updated for this study) and assumptions used for the 1995 Total System Performance Assessment (TSPA). The need for enhancements is determined by comparing the performance assessment results against the EBS related performance requirements. Subsystem quantitative performance requirements related to the EBS include the requirement to allow no more than 1% of the waste packages (WPs) to fail before 1,000 years after permanent closure of the repository, as well as a requirement to control the release rate of radionuclides from the EBS. The EBS performance enhancements considered included additional engineered components as well as evaluating additional performance available from existing design features but for which no performance credit is currently being taken

  18. Biogeochemical and engineered barriers for preventing spread of contaminants.

    Science.gov (United States)

    Baltrėnaitė, Edita; Lietuvninkas, Arvydas; Baltrėnas, Pranas

    2018-02-01

    The intensive industrial development and urbanization, as well as the negligible return of hazardous components to the deeper layers of the Earth, increases the contamination load on the noosphere (i.e., the new status of the biosphere, the development of which is mainly controlled by the conscious activity of a human being). The need for reducing the spread and mobility of contaminants is growing. The insights into the role of the tree in the reduction of contaminant mobility through its life cycle are presented to show an important function performed by the living matter and its products in reducing contamination. For maintaining the sustainable development, natural materials are often used as the media in the environmental protection technologies. However, due to increasing contamination intensity, the capacity of natural materials is not sufficiently high. Therefore, the popularity of engineered materials, such as biochar which is the thermochemically modified lignocellulosic product, is growing. The new approaches, based on using the contaminant footprint, as well as natural (biogeochemical) and engineered barriers for reducing contaminant migration and their application, are described in the paper.

  19. An RF cavity for barrier bucket experiment in the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Fujieda, M.; Iwashita, Y. [Kyoto Univ. (Japan); Mori, Y. [and others

    1998-11-01

    A barrier bucket experiment in the AGS is planed in 1998. An accumulation of the beam, which intensity of 1.0 x 10{sup 14}ppp is, acceleration after the injection with a barrier bucket scheme and other RF gymnastics experiments will be studied. An isolated RF pulse of 40 kV per cavity is necessary for the experiment. The RF frequency is 2 MHz and the isolated pulse is generated at the repetition rate of the revolution frequency of 357 kHz. We have developed the barrier cavity for this experiment. The cavity is loaded with FINEMET core. It has low Q value but high shunt impedance. It makes the necessary power less than that of ferrite-loaded cavity for an isolated RF pulse. (author)

  20. Reducing barriers to energy efficiency in the German mechanical engineering sector. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Schleich, J.; Boede, U.

    2000-12-01

    This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

  1. Reducing barriers to energy efficiency in the German mechanical engineering sector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Schleich, J.; Boede, U.

    2000-12-01

    This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

  2. Natural analog study of engineered protective barriers at the Hanford Site

    International Nuclear Information System (INIS)

    Bjornstad, B.N.; Teel, S.S.

    1993-09-01

    The purpose of this study is to evaluate surficial sedimentary deposits formed in the Pasco Basin over the geologic past as analogs for engineered protective barriers. Evidence for likely changes to be expected in an engineered barrier are preserved in geologically recent deposits. Although the design life of the engineered bonier is only 1,000 years, soils and sediments of this age are uncommon in the Pasco Basin. The evidence of and probability for the following natural processes that could adversely affect the long-term stability of an engineered protective barrier reviewed in this report are deflation by wind, soil compaction, soil eluviation/illuviation, bioturbation, and cryoturbation

  3. Backfill barriers: the use of engineered barriers based on geologic materials to assure isolation of radioactive wastes in a repository

    International Nuclear Information System (INIS)

    Apps, J.A.; Cook, N.G.W.

    1981-06-01

    A preliminary assessment is made to show that canisters fabricated of nickel-iron alloys, and surrounded by a suitable backfill, may produce an engineered barrier where the canister material is thermodynamically stable with respect to its environment. As similar conditions exist in nature, the performance of such systems as barriers to isolate radionuclides can be predicted over very long periods, of the order of 10 6 years

  4. Performance of engineered barrier materials in near surface disposal facilities for radioactive waste. Results of a co-ordinated research project

    International Nuclear Information System (INIS)

    2001-11-01

    The primary objectives of the CRP were to: promote the sharing of experiences of the Member States in their application of engineered barrier materials for near surface disposal facilities; help enhance their use of engineered barriers by improving techniques and methods for selecting, planning and testing performance of various types of barrier materials for near surface disposal facilities. The objective of this publication is to provide and overview of technical issues related to the engineered barrier systems and a summary of the major findings of each individual research project that was carried out within the framework of the CRP. This publication deals with a general overview of engineered barriers in near surface disposal facilities, key technical information obtained within the CRP and overall conclusions and recommendations for future research and development activities. Appendices presenting individual research accomplishments are also provided. Each of the 13 appendices was indexed separately

  5. Improved Barriers to Turbine Engine Fragments: Final Annual Report

    National Research Council Canada - National Science Library

    Shockey, Donald

    2002-01-01

    .... Previous large-scale fragment impact testing of comer peg-mounted fabric barriers indicated that the failure of the fabric around the pegged hole was a significant factor in the barrier's effectiveness...

  6. Evaluation of Subsurface Engineered Barriers at Waste Sites

    National Research Council Canada - National Science Library

    1998-01-01

    .... Environmental Protection Agency's (EPA) waste programs with a national retrospective analysis of barrier field performance, and information that may be useful in developing guidance on the use and evaluation of barrier systems...

  7. Deep disposal of high activity radioactive wastes: the study of engineered and geological barriers behaviour

    International Nuclear Information System (INIS)

    Yu Jun; Cui; Delage, P.; Laure, E. de; Behrouz, Gatmiri; Sulem, J.; Anh Minh, Tang

    2008-09-01

    One option for the isolation of high activity and long lived radioactive wastes is the disposal of the vitrified waste containers in galleries dug inside impermeable rocks of the deep underground (granite, argillite, salt). The multi-barrier isolation concept is based on the use of successive barriers to avoid the migration of radionuclides towards the biosphere (container envelope, engineered barrier made of compacted swelling clay, and host rock). In parallel to the works carried out in underground laboratories, experiments and simulation works are performed in order to understand the behaviour of storage facilities and barriers under the effects of constraints, water fluxes and temperature changes. In this context, the UR Navier geotechnical team (CERMES), a joint research unit of Ecole des Ponts ParisTech and LCPC, has been working for more than 15 years on this topic for various contractors. These works are based on original experimental devices allowing to identify the thermo-hydro-mechanical phenomena and thereafter to model them. This dossier presents a summary of these works. (J.S.)

  8. Engineered Barrier System Thermal-Hydraulic-Chemical Column Test Report

    International Nuclear Information System (INIS)

    W.E. Lowry

    2001-01-01

    The Engineered Barrier System (EBS) Thermal-Hydraulic-Chemical (THC) Column Tests provide data needed for model validation. The EBS Degradation, Flow, and Transport Process Modeling Report (PMR) will be based on supporting models for in-drift THC coupled processes, and the in-drift physical and chemical environment. These models describe the complex chemical interaction of EBS materials, including granular materials, with the thermal and hydrologic conditions that will be present in the repository emplacement drifts. Of particular interest are the coupled processes that result in mineral and salt dissolution/precipitation in the EBS environment. Test data are needed for thermal, hydrologic, and geochemical model validation and to support selection of introduced materials (CRWMS M and O 1999c). These column tests evaluated granular crushed tuff as potential invert ballast or backfill material, under accelerated thermal and hydrologic environments. The objectives of the THC column testing are to: (1) Characterize THC coupled processes that could affect performance of EBS components, particularly the magnitude of permeability reduction (increases or decreases), the nature of minerals produced, and chemical fractionation (i.e., concentrative separation of salts and minerals due to boiling-point elevation). (2) Generate data for validating THC predictive models that will support the EBS Degradation, Flow, and Transport PMR, Rev. 01

  9. Temperature effect on the behaviour of engineered clay barriers

    International Nuclear Information System (INIS)

    Tang, A.M.

    2005-11-01

    The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

  10. Characterization of cement paste as engineered barrier of borehole repository

    International Nuclear Information System (INIS)

    Ferreira, Eduardo G.A.; Isiki, Vera L. K.; Miyamoto, Hissae; Marumo, Julio T.; Vicente, Roberto

    2009-01-01

    Results of axial rupture by compression of cylindrical cement paste samples are presented. This is part of a research on cement paste behavior aiming at investigating the durability of cementitious materials in the environment of repositories for radioactive waste. Portland cement paste is intended to be used as a backfill in a deep borehole for disposal of sealed radiation sources which concept is under development. The service life of the engineered barrier materials plays an important role in the long term safety of such facilities. Accelerated tests in laboratory are being used to evaluate the performance of cement paste under the temperature expected at some hundred meters below grade, under exposure to the radiation emitted by the sources, and under the attack of aggressive chemicals dissolved in the groundwater, during the millennia necessary for the decay of the most active and long-lived radionuclides present in the waste. The large variability in results of mechanical strength as measured by axial compression of cylindrical samples is the subject of this short communication. (author)

  11. Advancing intercultural competency: Canadian engineering employers' experiences with immigrant engineers

    Science.gov (United States)

    Friesen, Marcia; Ingram, Sandra

    2013-05-01

    This paper explores Canadian engineering employers' perceptions of and experiences with internationally educated engineers (recent immigrants to Canada) employed in their organisations for varying lengths of time. Qualitative data were collected from employers using focus group methodology. Findings reflected employers' observations of culturally different behaviours and characteristics in their internationally educated employees, employers' reactions to cultural differences ranging from negative attributions to tolerance, and the implementation of largely ad hoc intra-organisational strategies for managing cultural differences in employer-employee relationships. Findings exposed the lack of corporate intercultural competency in the Canadian engineering profession. Equity and gatekeeping implications are discussed.

  12. Early wind engineering experiments in Denmark

    DEFF Research Database (Denmark)

    Larose, Guy; Franck, Niels

    1997-01-01

    A review of works by Danish wind engineers is presented to commemorate the 100th year anniversary of the first wind tunnel experiments. Pioneer tests by Irminger and Nøkkentved in "artificial" wind on scaled models are described. The early experiments aimed at measuring the surface pressure......" that governs today´s wind engineering practice and gave birth to the boundary layer wind tunnel....

  13. Remote Experiments in Control Engineering Education Laboratory

    Directory of Open Access Journals (Sweden)

    Milica B Naumović

    2008-05-01

    Full Text Available This paper presents Automatic Control Engineering Laboratory (ACEL - WebLab, an under-developed, internet-based remote laboratory for control engineering education at the Faculty of Electronic Engineering in Niš. Up to now, the remote laboratory integrates two physical systems (velocity servo system and magnetic levitation system and enables some levels of measurement and control. To perform experiments in ACEL-WebLab, the "LabVIEW Run Time Engine"and a standard web browser are needed.

  14. Reviews of the In-situ Demonstration Test of the Engineered Barrier System in Many Countries

    International Nuclear Information System (INIS)

    Lee, Minsoo; Choi, Heui Joo

    2013-01-01

    Many nations considering the deep geologic disposal of HLW are now planning or executing in-situ demonstration experiments on their regional EBS (Engineering barrier system) at their deep underground research facilities. The main purpose of the in-situ EBS test is the experimental confirmation of its performance, and the prediction of its long-term evolution through the modeling of EBS based on the experimental data. Additionally, the engineering feasibility for the construction of an engineering barrier system can also be checked through full scale construction of an in-situ test. KAERI is currently preparing an in-situ test at a large 1/3 scale, called IN-DEBS (In-situ Demonstration of EBS) at KURT (KAERI Underground Research Tunnel) for the generic EBS suggested in A-KRS (Advanced KAERI Reference System), which was developed to treat the HLW from pyroprocessing. As the first step for the design of IN-DEBS, the foreign in-situ demonstrations of EBS were reviewed in this paper. The demonstration projects, which were completed or are still being executed in some countries such as Sweden, France, Finland, Canada, Belgium, Switzerland, Spain, and Japan, were surveyed and summarized. In particular, hardware constitutions such as the heating element or compact bentonite, and the experimental procedures, have focused more on reviews than on experimental results in this survey, since their hardware information is very important for the design of the IN-DEBS

  15. Reviews of the In-situ Demonstration Test of the Engineered Barrier System in Many Countries

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Minsoo; Choi, Heui Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    Many nations considering the deep geologic disposal of HLW are now planning or executing in-situ demonstration experiments on their regional EBS (Engineering barrier system) at their deep underground research facilities. The main purpose of the in-situ EBS test is the experimental confirmation of its performance, and the prediction of its long-term evolution through the modeling of EBS based on the experimental data. Additionally, the engineering feasibility for the construction of an engineering barrier system can also be checked through full scale construction of an in-situ test. KAERI is currently preparing an in-situ test at a large 1/3 scale, called IN-DEBS (In-situ Demonstration of EBS) at KURT (KAERI Underground Research Tunnel) for the generic EBS suggested in A-KRS (Advanced KAERI Reference System), which was developed to treat the HLW from pyroprocessing. As the first step for the design of IN-DEBS, the foreign in-situ demonstrations of EBS were reviewed in this paper. The demonstration projects, which were completed or are still being executed in some countries such as Sweden, France, Finland, Canada, Belgium, Switzerland, Spain, and Japan, were surveyed and summarized. In particular, hardware constitutions such as the heating element or compact bentonite, and the experimental procedures, have focused more on reviews than on experimental results in this survey, since their hardware information is very important for the design of the IN-DEBS.

  16. Using a systems engineering process to develop engineered barrier system design concepts

    International Nuclear Information System (INIS)

    Jardine, L.J.; Short, D.W.

    1991-05-01

    The methodology used to develop conceptual designs of the engineered barrier system and waste packages for a geologic repository is based on an iterative systems engineering process. The process establishes a set of general mission requirements and then conducts detailed requirements analyses using functional analyses, system concept syntheses, and trade studies identifications to develop preliminary system concept descriptions. The feasible concept descriptions are ranked based on selection factors and criteria and a set of preferred concept descriptions is then selected for further development. For each of the selected concept descriptions, a specific set of requirements, including constraints, is written to provide design guidance for the next and more detailed phase of design. The process documents all relevant waste management system requirements so that the basis and source for the specific design requirements are traceable and clearly established. Successive iterations performed during design development help to insure that workable concepts are generated to satisfy the requirements. 4 refs., 2 figs

  17. H, HM, and THM-C processes in engineered barriers

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Y.J.; Tang, A.M.; Loiseau, C.; Delage, P.; Polak, M.; Souli, H.; Fleureau, J.M.; Wu, P.L.; Tien, Y.M.; Romero, E.; LI, Xiang Ling; Tanaka, Y.; Hasegawa, T.; Nakamura, K.; Sahara, F.; Murakami, T.; Kobayashi, I.; Mihara, M.; Ohi, T.; Lu, J.D.; Huang, W.H.; Lee, W.Y.; Sui, I.H.; Villar, M.V.; Sanchez, M.; Gens, A.; Samper, J.; Lu, C.; Montenegro, L.; Birgersson, M.; Karnland, O.; Nilsson, U.; Akesson, M.; Kristensson, O.; Gatabin, C.; Yang, C.R.; Huang, W.H.; Hsiao, T.H.; Dueck, A.; Lonnqvist, M.; Goudarzi, R.; Borgesson, L.; Fernandez, A.M.; Rivas, P.; Melon, A.M.; Villar, M.V.; Ferrow, E.; Bender Koch, Ch.; Suzuki, S.; Sazarashi, M.; Takegahara, T.; Takao, H.; Tanai, K.; Matsumoto, K.; Gatabin, C.; Touze, G.; Imbert, C.; Guillot, W.; Billaud, P

    2007-07-01

    This session gathers 24 articles (posters) dealing with: determining water permeability of a compacted bentonite sand mixture under confined and free-swell conditions; the model prediction of engineered barrier system effectiveness in the fracture at laboratory scale; the changes in the hydraulic properties of a smectite in presence of chromium; the wall friction and ejection behaviour of bentonite-base buffer material; the thermo-hydro-mechanical behaviour of a large scale mock-up test 'Ophelie' in Belgium: laboratory characterization and numerical modelling; modeling swelling characteristics and permeability of several compacted bentonite affected by saline water; modelling for the long-term Mechanical and Hydraulic behaviour of bentonite-based materials considering chemical transitions; the coupled thermal-hydro analysis on partially saturated bentonite; the behaviour of a bentonite barrier in the laboratory: experimental results up to 8 years and numerical simulation; a coupled hydrogeochemical calculations of the interactions of corrosion products and bentonite; the freezing in saturated bentonite: a thermodynamic approach; the mechanical modeling of MX-80: Development of constitutive laws; the mechanical modeling of MX-80 - Quick tools for BBM parameter analysis; TBT{sub 3} Mock-up test-experimental and model results; the suction characteristics of two compacted bentonite; the retention curves and volume change properties of unsaturated MX-80 bentonite: a laboratory study; humidity induced swelling and water absorption rate of highly compacted bentonite; unconfined compression tests on bentonite samples exposed to high temperature during long time in the field test lot; the thermophysical properties of bentonite; the geochemistry and mineralogy of a bentonite subjected to heating and hydration in an in-situ test after five years operation; the LOT project, long term test of buffer material at Aespoe: a Moessbauer spectroscopic study; the self

  18. Evaluation of Thermal Barrier and PS-200 Self-Lubricating Coatings in an Air-Cooled Rotary Engine

    Science.gov (United States)

    Moller, Paul S.

    1995-01-01

    This project provides an evaluation of the feasibility and desirability of applying a thermal barrier coating overlaid with a wear coating on the internal surfaces of the combustion area of rotary engines. Many experiments were conducted with different combinations of coatings applied to engine components of aluminum, iron and titanium, and the engines were run on a well-instrumented test stand. Significant improvements in specific fuel consumption were achieved and the wear coating, PS-200, which was invented at NASA's Lewis Research Center, held up well under severe test conditions.

  19. Performance Confirmation for the Engineered Barrier System. Report of a Workshop

    International Nuclear Information System (INIS)

    Bennett, David G.

    2004-08-01

    As part of preparations for review of future license applications, the Swedish Nuclear Power Inspectorate (SKI) organised a workshop on the engineered barrier system for the KBS-3 concept, focused on Performance Confirmation (PC). The workshop was held during 12 - 14 May, 2004 at Oskarshamn. The main purpose of the workshop was to identify key issues relating to the demonstration of long-term safety using a system of engineered barriers. The workshop began with introductory presentations on Performance Confirmation, on monitoring, and on long-term experiments in underground research laboratories. Working groups were then convened to discuss these topics and identify questions to put to the Swedish Nuclear Fuel and Waste Management Company (SKB) the following day. On the second day, SKB made several presentations, mainly on long-term experiments conducted at the Aespoe underground research laboratory. These presentations were followed by an informal session during which the questions identified by the working groups on the first day were discussed with SKB and its representatives. This report includes the questions identified by the working groups and a summary of the workshop discussions. Extended abstracts for the introductory presentations are included in an appendix. The conclusions and viewpoints presented in this report are those of one or several workshop participants. They do not necessarily coincide with those of SKI

  20. Surmounting the Barriers: Ethnic Diversity in Engineering Education: Summary of a Workshop

    Science.gov (United States)

    National Academies Press, 2014

    2014-01-01

    "Surmounting the Barriers: Ethnic Diversity in Engineering Education" is the summary of a workshop held in September 2013 to take a fresh look at the impediments to greater diversification in engineering education. The workshop brought together educators in engineering from two- and four-year colleges and staff members from the three…

  1. Clays in natural and engineered barriers for radioactive waste confinement - 4. International meeting. Book of abstracts

    International Nuclear Information System (INIS)

    2010-01-01

    proposed within the Strategic Research Agenda, elaborated through the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP). The conference offers a particular opportunity to present the more recent developments and main outputs of research carried out within the framework of national and international cooperative experiments and dedicated European projects. Contributions coming from fields other than radioactive waste disposal; like geological storage of natural gas, sequestration of CO 2 , energy storage in underground, chemical waste isolation, etc., also taking advantage of the properties of the clay material, were encouraged. This conference covers all topics concerning the natural argillaceous geological barriers and the clay-based engineered barrier systems, investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations, natural analogues, as well as numerical modelling and global integration approaches (including up-scaling processes and treatment of uncertainties) and monitoring. General strategy for clay based repository concepts Examples of research programmes (national or international) concerning the role of natural and engineered clay barriers for radioactive waste confinement including repository designs, safety assessment, full-scale demonstrations and implementations (e.g. heater tests). Geology and clay characterisation Clay mineralogy, sedimentology, paleo-environment, diagenesis, dating techniques, discontinuities in clay rock, fracturing, self-sealing processes, role of organic matters and microbiological processes, micro and nano characterisation of clay minerals and argillaceous rocks. Geochemistry Pore water geochemistry, clay thermodynamics, chemical retention, geochemical modelling, advanced isotopic geochemistry. Mass transfer Water status and hydraulic properties in low permeability media, pore space

  2. Centrifugal Pump Experiment for Chemical Engineering Undergraduates

    Science.gov (United States)

    Vanderslice, Nicholas; Oberto, Richard; Marrero, Thomas R.

    2012-01-01

    The purpose of this paper is to describe a Centrifugal Pump Experiment that provided an experiential learning experience to chemical engineering undergraduates at the University of Missouri in the spring of 2010 in the Unit Operations Laboratory course. Lab equipment was used by senior students with computer-based data and control technology. In…

  3. Performance of high level waste forms and engineered barriers under repository conditions

    International Nuclear Information System (INIS)

    1991-02-01

    The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

  4. Computational Experiments for Science and Engineering Education

    Science.gov (United States)

    Xie, Charles

    2011-01-01

    How to integrate simulation-based engineering and science (SBES) into the science curriculum smoothly is a challenging question. For the importance of SBES to be appreciated, the core value of simulations-that they help people understand natural phenomena and solve engineering problems-must be taught. A strategy to achieve this goal is to introduce computational experiments to the science curriculum to replace or supplement textbook illustrations and exercises and to complement or frame hands-on or wet lab experiments. In this way, students will have an opportunity to learn about SBES without compromising other learning goals required by the standards and teachers will welcome these tools as they strengthen what they are already teaching. This paper demonstrates this idea using a number of examples in physics, chemistry, and engineering. These exemplary computational experiments show that it is possible to create a curriculum that is both deeper and wider.

  5. Magnetic Materials: Novel Monitors of Long-Term Evolution of Engineered Barrier Systems

    Directory of Open Access Journals (Sweden)

    Simon L. Harley

    2016-12-01

    Full Text Available Most safety cases for the deep geological disposal of radioactive waste are reliant on the swelling of bentonite in the engineered barrier system as it saturates with groundwater. Assurance of safety therefore requires effective monitoring of bentonite saturation. The time- and fluid-dependent corrosion of synthetic magnets embedded in bentonite is demonstrated here to provide a novel and passive means of monitoring saturation. Experiments have been conducted at 70 °C in which neo magnets, AlNiCo magnets, and ferrite magnets have been reacted with saline (NaCl, KCl, CaCl2 solutions and alkaline fluids (NaOH, KOH, Ca(OH2 solutions; pH = 12 in the presence of bentonite. Nd-Fe-B magnets undergo extensive corrosion that results in a dramatic change from ferromagnetic to superparamagnetic behaviour concomitant with bentonite saturation. AlNiCo magnets in saline solutions show corrosion but only limited decreases in their magnetic intensities, and ferrite magnets are essentially unreactive on the experimental timescales, retaining their initial magnetic properties. For all magnets the impact of their corrosion on bentonite swelling is negligible; alteration of bentonite is essentially governed by the applied fluid composition. In principle, synthetic magnet arrays can, with further development, be designed and embedded in bentonite to monitor its fluid saturation without compromising the integrity of the engineered barrier system itself.

  6. IPR Barriers in Collaboration between University and Engineering Industry in Sweden

    OpenAIRE

    Huang, Wenting

    2011-01-01

    This thesis examines the barriers, especially intellectual property rights concerned that inhibit industry academia collaboration. By analyzing Swedish firms in the engineering industry, I explore the influence of IPR barrier on firms’ benefits, short- and long-term respectively from university-industry interaction. Three hypotheses are suggested to investigate the relationship between IPR barriers, firm categories, short-term benefits and long-term benefits. The results illustrate different ...

  7. TMX-U [Tandem Mirror Experiment-Upgrade] tandem-mirror thermal-barrier experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Baldwin, D.E.

    1986-01-01

    Thermal-barrier experiments have been carried out in the Tandem Mirror Experiment-Upgrade (TMX-U). Measurements of nonambipolar and ambipolar radial transport show that these transport processes, as well as end losses, can be controlled at modest densities and durations. Central-cell heating methods using ion-cyclotron heating (ICH) and neutral-beam injection have been demonstrated. Potential mesurements with recently developed methods indicate that deep thermal barriers can be established

  8. Improved Barriers to Turbine Engine Fragments: Final Annual Report

    National Research Council Canada - National Science Library

    Shockey, Donald

    2002-01-01

    This final annual technical report describes the progress rnade during year 4 of the SPI International Phase II effort to develop a computational capability for designing lightweight fragment barriers...

  9. Improved Barriers to Turbine Engine Fragments: Interim Report II

    National Research Council Canada - National Science Library

    Shockey, Donald

    1999-01-01

    Because fragments from in-flight engine failures can damage critical aircraft components and produce catastrophic consequences, the Federal Aviation Administration is sponsoring research to mitigate...

  10. Engineered surface barriers for waste disposal sites: lysimeter facility design and construction

    International Nuclear Information System (INIS)

    Phillips, S.J.; Ruben, M.S.; Kirkham, R.R.

    1988-01-01

    A facility to evaluate performance of engineered surface carriers for confinement of buried wastes has been designed, constructed, and operations initiated. The Field Lysimeter Test Facility is located at the US Department of Energy's Hanford Site in Richland, Washington. The facility consists of 18 one-dimensional drainage and weighing lysimeters used to evaluate 7 replicated barrier treatments. Distinct layers of natural earth materials were used to construct layered soil and rock barriers in each lysimeter. These barrier designs are capable in principal of significantly reducing or precluding infiltration of meteoric water through barriers into underlying contaminated zones. This paper summarizes salient facility design and construction features used in testing of the Hanford Site's engineered surface barriers

  11. Self-healing thermal barrier coatings; with application to gas turbine engines

    NARCIS (Netherlands)

    Ponnusami, S.A.

    2013-01-01

    Thermal Barrier Coating (TBC) systems have been applied in turbine engines for aerospace and power plants since the beginning of the 1980s to increase the energy efficiency of the engine, by allowing for higher operation temperatures. TBC systems on average need to be replaced about four times

  12. Remote Communication Engineering Experiments Through Internet

    Directory of Open Access Journals (Sweden)

    A. K. Gogoi

    2006-02-01

    Full Text Available In technical education, laboratory components comprise an essential and integral part without which engineering education remains incomplete. Experiments conducted on laboratory equipments lend a practical touch to the theoretical knowledge acquired by the students. However, setting up a specialized laboratory consisting of sophisticated and expensive equipments such as Digital Storage Oscilloscope, Signal Generator, Spectrum Analyzer and Network Analyzer is an expensive and unaffordable proposition for many universities and engineering colleges. Sophisticated technologies incorporated in recent models of such high-end equipments enable remote access through Internet to the instruments. This concept of accessing these expensive instruments over the Internet can be exploited by setting up a Remote Laboratory. This remote laboratory system aims at not only providing an opportunity to students from distant places to conduct hardware experiments but also to take the corresponding measurements. In this work, real-time hardware experiments have been designed and implemented. These are based on modulation techniques widely employed in Communication Engineering. An interactive Graphical User Interface (GUI environment has also been developed using Microsoft Visual Basic. This GUI is provided at the user end to facilitate the remote control and access of various instruments and experiment setups. It has been specifically designed and optimized for a low-bandwidth remote access link. The above mentioned system, as a whole, uses real-time capture of images and data from the instruments to perform experiment-related measurements.

  13. Natural analogue studies of engineered barrier materials at PNC Tokai, Japan

    International Nuclear Information System (INIS)

    Kamei, G.; Yusa, Y.; Yamagata, J.; Inoue, K.

    1991-01-01

    Long-term extrapolations concerning the safety of a nuclear waste repository cannot be satisfactorily made on the sole basis of short-term laboratory tests. Natural analogues, which are the only means by which very slow mechanisms can be identified and by which long-term predictions of models can be tested for pertinence. Our natural analogue studies for the assessment of long-term durability of engineered barrier materials are outlined. Materials of young age and with simple history are the most suitable for the studies as: 1) properties of the materials tend to deteriorate over the longer term; and 2) detailed quantitative data on the term and on the environmental conditions can be obtained. The framework of our studies includes: 1) clarification of alteration phenomena, 2) examination of the environmental conditions, and 3) support experiments. (author)

  14. Engineered Barrier System - Manufacturing, Testing and Quality Assurance. Report from a Workshop

    International Nuclear Information System (INIS)

    2004-06-01

    As part of preparations for review of future license applications, the Swedish Nuclear Power Inspectorate (SKI) organised a workshop on the engineered barrier system for the KBS-3 concept, with the focus on manufacturing, testing and quality assurance. The main purpose of the workshop was to identify critical issues in the demonstration of how long-term safety requirements could be fulfilled for the engineered barriers. The workshop included presentations related to engineered barrier manufacturing and testing held by external experts, and working group sessions to prepare questions to the Swedish Nuclear Fuel and Waste Management Co. (SKB). SKB presentations were followed by an informal questioning and discussion with SKB representatives. This report includes a presentation of the questions posed by the working groups, SKB's replies to these questions as well as a summary of the working group discussions. The conclusions and viewpoints presented in this report are those of one or several workshop participants. During the workshop many issues regarding manufacturing, testing and quality assurance of the engineered barriers were discussed. The central themes in the questions and discussions are summarised as follows: There is a need to specify how the functional requirements for the buffer and backfill will be achieved in practise. Issues of particular interest are material selection, compaction density, initial water content and manufacturing methods for bentonite blocks. A major problem that must be addressed is the long period required to obtain relevant results from large-scale testing. The uncertainties relating to the wetting and subsequent swelling processes of the bentonite buffer have implications for analysis of the canister. It is necessary to know now non-uniform the bentonite swelling pressure could be in a worst case pressure differential, in order to evaluate the sufficiency of 'as tested' canister performance. Regarding the copper shell of the

  15. Engineered passive bioreactive barriers: risk-managing the legacy of industrial soil and groundwater pollution.

    Science.gov (United States)

    Kalin, Robert M

    2004-06-01

    Permeable reactive barriers are a technology that is one decade old, with most full-scale applications based on abiotic mechanisms. Though there is extensive literature on engineered bioreactors, natural biodegradation potential, and in situ remediation, it is only recently that engineered passive bioreactive barrier technology is being considered at the commercial scale to manage contaminated soil and groundwater risks. Recent full-scale studies are providing the scientific confidence in our understanding of coupled microbial (and genetic), hydrogeologic, and geochemical processes in this approach and have highlighted the need to further integrate engineering and science tools.

  16. Industrial characterization and validation of clay materials like engineering barrier

    International Nuclear Information System (INIS)

    Rivas, P.; Villar, M.V.; Martin, P.L.; Perez del Villar, L.; Cruz, B. de la; Cozar, J.S.; Dardaine, M.; Lajudie, A.

    1993-01-01

    This report analyzes the bentonites in Madrid and Almeria in order to select the material to built the barrier between the containers and granitic LOCK. The main objective was focussed to test radioactive waste storage in granitic LOCK. The institutions involved in this project are, CIEMAT (Spain), CEA (France), UAM (Spain) and CSIC (Spain)

  17. Progress in waste package and engineered barrier system performance assessment and design

    International Nuclear Information System (INIS)

    Van Luik, A.; Stahl, D.; Harrison, D.

    1993-01-01

    As part of the U.S. Department of Energy's evaluation of site suitability for a potential high-level radioactive waste repository, long-term interactions between the engineered barrier system and the site must be determined. This requires a waste-package/engineered-system design, a description of the environment around the emplacement zone, and models that simulate operative processes describing these engineered/natural systems interactions. Candidate designs are being evaluated, including a more robust, multi-barrier waste package, and a drift emplacement mode. Tools for evaluating designs, and emplacement mode are the currently available waste-package/engineered-system performance assessment codes development for the project. For assessments that support site suitability, environmental impact, or licensing decisions, more capable codes are needed. Code capability requirements are being written, and existing codes are to be evaluated against those requirements. Recommendations are being made to focus waste-packaging/engineered-system code-development

  18. Environmental Barrier Coatings for Turbine Engines: A Design and Performance Perspective

    Science.gov (United States)

    Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis; Smialek, James L.; Miller, Robert A.

    2009-01-01

    Ceramic thermal and environmental barrier coatings (TEBC) for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating long-term durability remains a major concern with the ever-increasing temperature, strength and stability requirements in engine high heat-flux combustion environments, especially for highly-loaded rotating turbine components. Advanced TEBC systems, including nano-composite based HfO2-aluminosilicate and rare earth silicate coatings are being developed and tested for higher temperature capable SiC/SiC ceramic matrix composite (CMC) turbine blade applications. This paper will emphasize coating composite and multilayer design approach and the resulting performance and durability in simulated engine high heat-flux, high stress and high pressure combustion environments. The advances in the environmental barrier coating development showed promise for future rotating CMC blade applications.

  19. Engineering-scale dust control experiments

    International Nuclear Information System (INIS)

    Winberg, M.R.; Pawelko, R.J.; Jacobs, N.C.; Thompson, D.N.

    1990-12-01

    This report presents the results of engineering scale dust-control experiments relating to contamination control during handling of transuranic waste. These experiments focused on controlling dust during retrieval operations of buried waste where waste and soil are intimately mixed. Sources of dust generation during retrieval operations include digging, dumping, and vehicle traffic. Because contaminants are expected to attach to soil particles and move with the generated dust, control of the dust spread may be the key to contamination control. Dust control techniques examined in these experiments include the use of misting systems, soil fixatives, and dust suppression agents. The Dryfog Ultrasonic Misting Head, manufactured by Sonics, Incorporated, and ENTAC, an organic resin derived from tree sap manufactured by ENTAC Corporation, were tested. The results of the experiments include product performance and recommended application methods. 19 figs., 7 refs., 6 tabs

  20. Small scale model and underground laboratory study of engineered barrier thermal behaviour

    International Nuclear Information System (INIS)

    Dardaine, M.; Beziat, A.; Gatabin, C.; Lefevre, I.; Plas, F.; Fontan, N.; Moyne, C.

    1991-01-01

    This is the final report of the contract CCE FI1W/0061, which had the objective of studying the thermal behaviour of the engineered barrier having the selected French clay Fo-Ca (natural calcic smectite) as its major constituent. After being installed this barrier was subjected simultaneously to the heat flux dissipated by the container and to a possible rehydration by contact with the host medium. It consists of three parts. The first part is devoted to R and D studies concerning detectors suitable for the point measurement of the water concentration. Among the techniques that can be envisaged, capacitor methods, which are very temperature sensitive, would require a great deal of effort to be satisfactory. On the other hand, the water concentration can, in principle, be derived from the measurement of the thermal conductivity in the transient regime. Although the carrying out of this measurement is somewhat critical, it can give good results under certain conditions. The second part reports experiments carried out in the laboratory concerning both the study of heat transfer during the so-called dry phase of the disposal (without any water being supplied externally) and the study of the phenomenon of fissuration. Finally, the third part describes the in situ experiment BACCHUS, carried out in the underground test facility at Mol (Belgium), in collaboration with the CEN/SCK. In the course of the five months of the thermal phase of this experiment a large variation in the amplitude of the temperature gradients was recorded, which may be explained, on one hand, by the convergence of the medium and, on the other hand, by a much more rapid rehydration than that predicted

  1. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed

  2. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  3. Influences of engineered barrier systems on low-level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, L. P.

    1987-09-15

    There are major differences between the current practices of shallow land burial and alternative concepts for the disposal of low-level radioactive wastes. Additional protection provided with engineered barrier systems can overcome major concerns the public has with shallow land burial: subsidence; percolating ground waters; radionuclide migration; and the vulnerability of shallow trenches to intrusion. The presence of a variety of engineered barriers to restrict water movement, retain radionuclides and to prevent plant animal or human intrusion leads to significant changes to input data for performance assessment models. Several programs which are underway to more accurately predict the long-term performance of engineered barriers for low-level waste will be described.

  4. Influences of engineered barrier systems on low-level radioactive waste disposal

    International Nuclear Information System (INIS)

    Buckley, L.P.

    1987-09-01

    There are major differences between the current practices of shallow land burial and alternative concepts for the disposal of low-level radioactive wastes. Additional protection provided with engineered barrier systems can overcome major concerns the public has with shallow land burial: subsidence; percolating ground waters; radionuclide migration; and the vulnerability of shallow trenches to intrusion. The presence of a variety of engineered barriers to restrict water movement, retain radionuclides and to prevent plant animal or human intrusion leads to significant changes to input data for performance assessment models. Several programs which are underway to more accurately predict the long-term performance of engineered barriers for low-level waste will be described

  5. Functions of an engineered barrier system for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Coons, W.E.; Moore, E.L.; Smith, M.J.; Kaser, J.D.

    1980-01-01

    Defined in this document are the functions of components selected for an engineered barrier system for a nuclear waste repository in basalt. The definitions provide a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five-component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed in terms of effective operation throughout the course of repository history, recognizing that the emplacement environment changes with time. While components of the system are mutually supporting, redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The operating philosophy of the conceptual engineered barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed. A method for system validation and qualification is also included which considers performance criteria proposed by external agencies in conjunction with site-specific models and risk assessment to define acceptable levels of system performance

  6. Sustainable Hydraulic Barrier Design Technologies for Effective Infrastructure Engineering

    Directory of Open Access Journals (Sweden)

    Chitral Wijeyesekera Devapriya

    2017-01-01

    Full Text Available Migration of liquids lead to embarrassing post construction scenarios such as that of leaks from roofs, potable water leaking from water tanks/ reservoirs, rising damp in walls with groundwater seeping into basement structures, leakage of water from ornamental lakes and ponds or leachate leakage into the environment from MSW landfill sites. Such failures demand immediate and expensive maintenance. A stringent control on structural and waterproof stability is deemed necessary for long term service life of structures and in particular underground and near surface structures. On a micro scale and over a longer time scale, the phenomenon of rising dampness occurs in older buildings with the groundwater rising up through walls, floors and masonry via capillary action. Even slower rates of contaminant fluid migration occur through landfill base liners. In this paper a variety of hydraulic barrier technologies is critically discussed against a backdrop of relevant case studies. The choice of an appropriate hydraulic barrier technology for a given scenario will depend also on the sustainability, financial affordability and subjective aesthetics.

  7. Thermal analysis of the effect of thick thermal barrier coatings on diesel engine performance

    International Nuclear Information System (INIS)

    Hoag, K.L.; Frisch, S.R.; Yonushonis, T.M.

    1986-01-01

    The reduction of heat rejection from the diesel engine combustion chamber has been the subject of a great deal of focus in recent years. In the pursuit of this goal, Cummins Engine Company has received a contract from the Department of Energy for the development of thick thermal barrier coatings for combustion chamber surfaces. This contract involves the analysis of the impact of coatings on diesel engine performance, bench test evaluation of various coating designs, and single cylinder engine tests. The efforts reported in this paper center on the analysis of the effects of coatings on engine performance and heat rejection. For this analysis the conventional water cooled engine was compared with an engine having limited oil cooling, and utilizing zirocnia coated cylinder had firedecks and piston crowns. The analysis showed little or no benefits of similarly coating the valves or cylinder liner

  8. Engineered barrier systems (EBS) in the context of the entire safety case

    International Nuclear Information System (INIS)

    2003-01-01

    A joint NEA-EC workshop entitled 'Engineered Barrier Systems (EBS) in the Context of the Entire Safety Case' was organised in Oxford on 25-27 September 2002 and hosted by United Kingdom Nirex Limited. The main objectives of the workshop were to provide a status report on engineered barrier systems in various national radioactive waste management programmes considering deep geological disposal; to establish the value to member countries of a project on EBS; and to define such a project's scope, timetable and modus operandi. This report presents the outcomes of this workshop. (author)

  9. Engineered Barrier Systems (EBS) in the Context of the Entire Safety Case

    International Nuclear Information System (INIS)

    2005-01-01

    A joint NEA-EC workshop entitled ''Engineered Barrier Systems (EBS) in the Context of the Entire Safety Case'' was organised in Oxford on 25-27 September 2002 and hosted by United Kingdom Nirex Limited. The main objectives of the workshop were to provide a status report on engineered barrier systems in various national radioactive waste management programmes considering deep geological disposal; to establish the value to member countries of a project on EBS; and to define such a project scope, timetable and modus operandi. This report presents the outcomes of this workshop. (author)

  10. Teaching Ethics to Engineers: A Socratic Experience.

    Science.gov (United States)

    Génova, Gonzalo; González, M Rosario

    2016-04-01

    In this paper we present the authors' experience of teaching a course in Ethics for Engineers, which has been delivered four times in three different universities in Spain and Chile. We begin by presenting the material context of the course (its place within the university program, the number of students attending, its duration, etc.), and especially the intellectual background of the participating students, in terms of their previous understanding of philosophy in general, and of ethics in particular. Next we set out the objectives of the course and the main topics addressed, as well as the methodology and teaching resources employed to have students achieve a genuine philosophical reflection on the ethical aspects of the profession, starting from their own mindset as engineers. Finally we offer some results based on opinion surveys of the students, as well as a more personal assessment by the authors, recapitulating the most significant achievements of the course and indicating its underlying Socratic structure.

  11. Design of Experiments for Food Engineering

    DEFF Research Database (Denmark)

    Pedersen, Søren Juhl; Geoffrey Vining, G.

    This work looks at the application of Design of Experiments (DoE) to Food Engineering (FE) problems in relation to quality. The field of Quality Engineering (QE) is a natural partnering field for FE due to the extensive developments that QE has had in using DoE for quality improvement especially...... in manufacturing industries. In the thesis the concepts concerning food quality is addressed and in addition how QE proposes to define quality. There is seen a merger in how QE’s definition of quality has been translated for food. At the same time within FE a divergence has been proposed in the literature...... that the fundamental principles of DoE have as much importance and relevance as ever for both the food industry and FE research....

  12. Technical problems and future underground engineering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, G H [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1969-07-01

    The technical problems to be solved in future underground engineering experiments are of two kinds. One concerns adequate description of the variation of nuclear explosion effects with physical nd chemical properties of the explosion site. The other concerns engineering of the explosive detonation system to provide adequate safety and security, concurrently with minimum total costs per explosion. The semiempirical equations for explosion effects can be trusted only in the range of explosive energy, depth of burst, and rock type for which there is prior experience. Effects calculations based on the principles of continuum mechanics and measurable geophysical properties appear to work in the few test cases, such as Gasbuggy, to which they have been applied. These calculational methods must be tested in a variety of situations. The relevance of dynamic and static measurements on Dragon Trail, Bronco, Rulison, Stoop, Ketch, and Pinedale to proving the methods are discussed in this paper. The traditional methods of assembling and fielding nuclear explosives have evolved from practice at the Nevada Test Site. These provide great flexibility and assure maximum recovery of all data from each test, thus minimizing the time required to achieve desired results. Timing and firing, radiation monitoring, explosives assembly and emplacement, explosive performance, weather monitoring, and dynamic measurements of earth and building motion have all been handled traditionally as independent functions. To achieve lower costs in underground engineering experiments and projects, one prototype system combining all electronic, measurement, and communication functions is being built. Much further work will be required to complete this effort, including, especially, an examination of safety criteria and means for assuring operational and public safety at reduced costs. (author)

  13. Technical problems and future underground engineering experiments

    International Nuclear Information System (INIS)

    Higgins, G.H.

    1969-01-01

    The technical problems to be solved in future underground engineering experiments are of two kinds. One concerns adequate description of the variation of nuclear explosion effects with physical nd chemical properties of the explosion site. The other concerns engineering of the explosive detonation system to provide adequate safety and security, concurrently with minimum total costs per explosion. The semiempirical equations for explosion effects can be trusted only in the range of explosive energy, depth of burst, and rock type for which there is prior experience. Effects calculations based on the principles of continuum mechanics and measurable geophysical properties appear to work in the few test cases, such as Gasbuggy, to which they have been applied. These calculational methods must be tested in a variety of situations. The relevance of dynamic and static measurements on Dragon Trail, Bronco, Rulison, Stoop, Ketch, and Pinedale to proving the methods are discussed in this paper. The traditional methods of assembling and fielding nuclear explosives have evolved from practice at the Nevada Test Site. These provide great flexibility and assure maximum recovery of all data from each test, thus minimizing the time required to achieve desired results. Timing and firing, radiation monitoring, explosives assembly and emplacement, explosive performance, weather monitoring, and dynamic measurements of earth and building motion have all been handled traditionally as independent functions. To achieve lower costs in underground engineering experiments and projects, one prototype system combining all electronic, measurement, and communication functions is being built. Much further work will be required to complete this effort, including, especially, an examination of safety criteria and means for assuring operational and public safety at reduced costs. (author)

  14. First Experiences with Google Earth Engine

    OpenAIRE

    Navarro, José A.

    2017-01-01

    This paper presents the first experiences of the author with GEE (Google Earth Engine). A C++ image processing algorithm, still under development, was migrated to this new environment using GEE’s web interface and the JavaScript language. The idea is to discover the problems that might arise when migrating to this environment as well as to assess the presumable performance boost that should be achieved. A reduced—more didactic—version of the aforementioned algorithm is presented in a step-by-...

  15. Exploring Barriers to Medication Safety in an Ethiopian Hospital Emergency Department: A Human Factors Engineering Approach

    Directory of Open Access Journals (Sweden)

    Ephrem Abebe

    2018-02-01

    Full Text Available Objective: To describe challenges associated with the medication use process and potential medication safety hazards in an Ethiopian hospital emergency department using a human factors approach. Methods: We conducted a qualitative study employing observations and semi-structured interviews guided by the Systems Engineering Initiative for Patient Safety model of work system as an analytical framework. The study was conducted in the emergency department of a teaching hospital in Ethiopia. Study participants included resident doctors, nurses, and pharmacists. We performed content analysis of the qualitative data using accepted procedures. Results: Organizational barriers included communication failures, limited supervision and support for junior staff contributing to role ambiguity and conflict. Compliance with documentation policy was minimal. Task related barriers included frequent interruptions and work-related stress resulting from job requirements to continuously prioritize the needs of large numbers of patients and family members. Person related barriers included limited training and work experience. Work-related fatigue due to long working hours interfered with staff’s ability to document and review medication orders. Equipment breakdowns were common as were non-calibrated or poorly maintained medical devices contributing to erroneous readings. Key environment related barriers included overcrowding and frequent interruption of staff’s work. Cluttering of the work space compounded the problem by impeding efforts to locate medications, medical supplies or medical charts. Conclusions: Applying a systems based approach allows a context specific understanding of medication safety hazards in EDs from low-income countries. When developing interventions to improve medication and overall patient safety, health leaders should consider the interactions of the different factors. Conflict of Interest We declare no conflicts of interest or

  16. FEBEX: Full-Scale engineered barriers experiment in crystalline host-rock: preoperational phase. Synthesized report; FEBEX: experimento de barreras de ingenieria a gran escala en rocas cristalinas: etapa preoperacional. Informe de sintesis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The FEBEX project is being cofinanced by the EC under contract F 14WCT950006. In addition to the EC, seven partners from three countries of the EU. (France, Germany, and Spain) as well as one from EFTA (Switzerland) are participating in the project. ENRESA is the coordinating partner with NAGRA assisting in coordinating some aspects. The project consists of two large-scale tests and a series of complimentary laboratory tests. The work is being executed by the following organizations: CIEMAT, AITEMIN, UP-DIT (CIMNE), ULC, CSIC-Zaidin, and UPM (SPAIN) ANDRA and G.3S (FRANCE) GRS (GERMANY). This report includes a synthesized description of the experiment from its conception through the installation of the two large-scale tests (from the middle of 1994 to the beginning of 1997, preoperation stage). The experiment is described in detail in a series of specific reports. (Author)

  17. Value engineering study for seletion of verticle barrier technology at a Superfund site

    International Nuclear Information System (INIS)

    Bryan, E.E.; Guglielmetti, J.L.; Butler, P.B.; Brill, M.P.

    1997-01-01

    A value engineering (VE) study was conducted to identify and evaluate vertical barrier technologies and alignments for a Superfund project in New Castle County, Delaware. The objective was to select and recommend the most appropriate vertical barrier(s) for two separate landfills and a portion of the manufacturing plant on the site. A VE team was assembled to identify and evaluate site specific issues related to effectiveness, constructability and cost for numerous vertical barrier technologies. Several cost-effective alternatives were identified that met project objectives. The VE study concluded that a composite vertical barrier system consisting of a soil-bentonite slurry trench and steel sheet piles would provide effective containment of the North Landfill. Additionally, the geologic confining unit specified in the Record of Decision (ROD) was found to be unsuitable as a vertical barrier key and a more suitable, shallow confining unit was discovered. This paper describes the value engineering process and results of the VE study for one of the landfills

  18. Durability of Dukovany shallow land repository engineered barriers. Appendix 7: Czech Republic

    International Nuclear Information System (INIS)

    Vokal, A.; Nachmilner, L.; Wasserbauer, R.; Dohnalek, J.

    2001-01-01

    The main aim of this project was to explore the durability of engineering barriers used at Dukovany shallow land repository as a support of safety assessments. This appendix summarises the principal results focused on durability of asphaltopropyleneconcrete (APC) hydroisolation and steel reinforced concrete construction

  19. Employees' Perceptions of Barriers to Participation in Training and Development in Small Engineering Businesses

    Science.gov (United States)

    Susomrith, Pattanee; Coetzer, Alan

    2015-01-01

    Purpose: This paper aims to investigate barriers to employee participation in voluntary formal training and development opportunities from the perspective of employees in small engineering businesses. Design/methodology/approach: An exploratory qualitative methodology involving data collection via site visits and in-depth semi-structured…

  20. Loadings in thermal barrier coatings of jet engine turbine blades an experimental research and numerical modeling

    CERN Document Server

    Sadowski, Tomasz

    2016-01-01

    This book discusses complex loadings of turbine blades and protective layer Thermal Barrier Coating (TBC), under real working airplane jet conditions. They obey both multi-axial mechanical loading and sudden temperature variation during starting and landing of the airplanes. In particular, two types of blades are analyzed: stationary and rotating, which are widely applied in turbine engines produced by airplane factories.

  1. Engineering education for youth: Diverse elementary school students' experiences with engineering design

    Science.gov (United States)

    Hegedus, Theresa

    Lingering concerns over the persistent achievement gap amidst the trend of an increasingly diverse society have been compounded by calls from the Oval Office, the National Science Board, and nationwide media to also address our current creativity crisis. Now, more than ever, we have a responsibility to produce a STEM-capable (science, technology, engineering, and mathematics) workforce to meet the demands of our rapidly changing local and global economic landscape. Barriers exist in our traditional educational system, which has historically limited underrepresented groups' affiliation and membership in the disciplines of science and engineering. The recent incorporation of engineering into the latest science education reform efforts presents an opportunity to expose students as early as elementary school to engineering practices and habits of mind, which have the potential to stimulate creative thinking skills through engineering design. This qualitative study was designed to examine the ways in which engineering education has the potential to promote creativity and academic competence in elementary science classrooms. As a part of my study, a diverse group of students from two fifth-grade classrooms took part in a 10-12 hour, engineering-based curriculum unit (Engineering is Elementary) during their regular science instructional time. Using a sociocultural lens, to include cultural production and identities in practice as part of my framework, I analyzed group and individual performances through classroom observations, student interviews, and teacher reflections to better understand the meaning students made of their experiences with engineering. Findings from the study included the ways in which creativity was culturally produced in the classroom to include: 1) idea generation; 2) design and innovation; 3) gumption/resourcefulness; and 4) social value. Opportunities for collaboration increased through each stage of the unit culminating with the design challenge

  2. The EC/NEA engineered barrier systems project

    International Nuclear Information System (INIS)

    Umeki, Hiroyuki; Forinash, Elizabeth K.; Davies, Christophe; Bennett, David; Hooper, Alan; Van Luik, Abe; Voinis, Sylvie

    2008-01-01

    This paper presents examples from various disposal programmes and discusses lessons that may be drawn relating to disposal system design and the use of underground tests. Many useful large-scale experiments have been conducted in underground laboratories that have allowed an assessment of the feasibility of methods for tunnel construction, waste package emplacement, buffer and backfill emplacement, tunnel seal construction, etc. In general, these tests have been successful and have shown that the necessary techniques for manufacturing and installing EBS components are feasible and available. In some cases, tests have shown that designs or techniques need to be adjusted, or have enabled identification of the factors to be taken into account in future optimisation studies. Further trials of some methods are still required, particularly at the repository or industrial scale. Further experiments are also likely to be required to increase understanding of the long-term behaviour of the EBS after installation. (author)

  3. International conference on the performance of engineered barriers. Physical and chemical properties, behaviour and evolution. Short abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Schaefers, Annika; Fahland, Sandra (eds.)

    2014-08-01

    The volume includes the abstracts of the papers presented at the international conference on the performance of engineered barrier systems, their physical and chemical properties, behavior and evolution. The papers cover the topics bentonite buffers, radioactive waste repository safety, geophysical and geochemical property monitoring, repository sealing materials, thermo-hydro-mechanical characterization, gas injection tests, hydration and heating tests, clay-iron interaction experiments, water retention behavior, thermal stability of materials, numerical modeling studies, long-term simulations, thermo-hydrologic phenomena, uncertainty and sensitivity studies, probabilistic assessments, preliminary safety analyses of Gorleben.

  4. Engineered clay-shredded tyre mixtures as barrier materials

    International Nuclear Information System (INIS)

    Al-Tabbaa, A.; Aravinthan, T.

    1997-01-01

    An engineered clay consisting of kaolin and bentonite was mixed with shredded tyre in various weight percentages and examined for use as a constituent in a landfill liner. The clay-tyre mixtures properties in terms of compaction, unconfined compressive strength, permeability to water and paraffin, leachability, stress-strain behaviour, free swell behaviour and swelling pressure were investigated. The results show that the dry density and strength reduced with the addition of tyre and also with increased tyre content but that good interaction was developed between the clay and tyre. The strain at failure increased showing reinforcing effect of the tyre. The permeability to paraffin was considerably reduced compared to that to water due to the presence of the tyre which caused high swelling pressures to develop. The leachability results indicate initial high concentrations leaching out of the soil-tyre mixtures which will be subjected to dilution in the environment. This work adds evidence to the potential advantages of using soil-tyre mixtures as a landfill liner material

  5. Physicochemical and Geotechnical Alterations to MX-80 Bentonite at the Waste Canister Interface in an Engineered Barrier System

    Directory of Open Access Journals (Sweden)

    Christopher W. Davies

    2017-08-01

    Full Text Available The study investigated the basic geomechanical and mineralogical evolution of the bentonite barrier under various experimental boundary conditions which replicated the near-field Thermo-Hydro-Chemico (THC conditions in a repository. The relationships between the physicochemical alterations and changes in the geotechnical properties have seldom been studied, especially on a consistent dataset. This paper attempts to link the physicochemical properties of Na-bentonite (MX-80 to the macro-scale engineering functionality of the bentonite post THC exposure. Experiments investigated the impact of THC variables on the engineering and physicochemical functionality of the bentonite with respect to its application within a High-Level Waste (HLW engineered barrier system. Intrinsic alterations to the MX-80 bentonite under relatively short-term exposure to hydrothermal and chemical conditions were measured. Additionally, two long-term tests were conducted under ambient conditions to consider the impact of exposure duration. The intrinsic measurements were then related to the overall performance of the bentonite as a candidate barrier material for application in a UK geological disposal facility. Findings indicate that exposure to thermo-saline-corrosion conditions (i.e., corrosion products derived from structural grade 275 carbon steel inhibits the free swell capacity and plasticity of the bentonite. However, the measured values remained above the design limits set out for the Swedish multi-barrier concept, from which the UK concept may take a lead. Corrosion alone does not appear to significantly affect the geotechnical measurements compared with the influence of thermal loading and high saline pore water after relatively short-term exposure. Thermal and corrosion exposure displayed no impact on the intrinsic swelling of the smectite component, indicating that no significant structural alteration had occurred. However, when exploring more complex saline

  6. An assessment of gas impact on geological repository. Methodology and material property of gas migration analysis in engineered barrier system

    International Nuclear Information System (INIS)

    Yamamoto, Mikihiko; Mihara, Morihiro; Ooi, Takao

    2004-01-01

    Gas production in a geological repository has potential hazard, as overpressurisation and enhanced release of radionuclides. Amongst data needed for assessment of gas impact, gas migration properties of engineered barriers, focused on clayey and cementitious material, was evaluated in this report. Gas injection experiments of saturated bentonite sand mixture, mortar and cement paste were carried out. In the experiments, gas entry phenomenon and gas outflow rate were observed for these materials. Based on the experimental results, two-phase flow parameters were evaluated quantitatively. A conventional continuum two-phase flow model, which is only practically used multidimensional multi-phase flow model, was applied to fit the experimental results. The simulation results have been in good agreement with the gas entry time and the outflow flux of gas and water observed in the experiments. It was confirmed that application of the continuum two-phase flow model to gas migration in cementitious materials provides sufficient degree of accuracy for assessment of repository performance. But, for sand bentonite mixture, further extension of basic two-phase flow model is needed especially for effect of stress field. Furthermore, gas migration property of other barrier materials, including rocks, but long-term gas injection test, clarification of influence of chemicals environment and large-scale gas injection test is needed for multi-barrier assessment tool development and their verification. (author)

  7. Investigation of metallic, ceramic, and polymeric materials for engineered barrier applications in nuclear-waste packages

    International Nuclear Information System (INIS)

    Westerman, R.E.

    1980-10-01

    An effort to develop licensable engineered barrier systems for the long-term (about 1000 yr) containment of nuclear wastes under conditions of deep continental geologic disposal has been underway at Pacific Northwest Laboratory since January 1979, under the auspices of the High-Level Waste Immobilization Program. In the present work, the barrier system comprises the hard or structural elements of the package: the canister, the overpack(s), and the hole sleeve. A number of candidate metallic, ceramic, and polymeric materials were put through mechanical, corrosion, and leaching screening tests to determine their potential usefulness in barrier-system applications. Materials demonstrating adequate properties in the screening tests will be subjected to more detailed property tests, and, eventually, cost/benefit analyses, to determine their ultimate applicability to barrier-system design concepts. The following materials were investigated: two titanium alloys of Grade 2 and Grade 12; 300 and 400 series stainless steels, Inconels, Hastelloy C-276, titanium, Zircoloy, copper-nickel alloys and cast irons; total of 14 ceramic materials, including two grades of alumina, plus graphite and basalt; and polymers such as polyamide-imide, polyarylene, polyimide, polyolefin, polyphenylene sulfide, polysulfone, fluoropolymer, epoxy, furan, silicone, and ethylene-propylene terpolymer (EPDM) rubber. The most promising candidates for further study and potential use in engineered barrier systems were found to be rubber, filled polyphenylene sulfide, fluoropolymer, and furan derivatives

  8. Clays in natural and engineered barriers for radioactive waste confinement - 5. International meeting. Book of abstracts

    International Nuclear Information System (INIS)

    2012-10-01

    The purpose of this fifth international meeting is to bring again together specialists in the different disciplines related to clays and clay minerals, with scientists from organizations engaged in disposal of radioactive waste in order to evaluate the progress of the research conducted in that field. Multidisciplinary approaches including geology, mineralogy, geochemistry, rheology, physics and chemistry of clay minerals and assemblages are required in order to provide a detailed characterization of the geological host formations considered for the disposal of radioactive waste and to assess the behaviour of engineered and natural barriers when submitted to various types of perturbations induced by such facilities. The evaluation of the performances of the natural barrier as well as of the impact of repository-induced disturbances upon the confinement properties of clay-rich geological formations constitute major objectives for the experimental programs being and/or to be conducted in underground research laboratories, for interpreting the subsequent scientific results, for modelling the long-term behaviour of radioactive waste repositories and carrying out safety assessment exercises. The meeting covers all the aspects of clay characterization and behaviour considered at various times and space scales relevant to confinement of radionuclides in clay from basic phenomenological processes description, to the global understanding of the performance and safety at repository and geological scales. Special emphasis will be put on the modelling of processes occurring at the mineralogical level within the clay barriers. The topics covered by the program of the meeting are also supposed to be coherent with the general objectives proposed within the Strategic Research Agenda elaborated through the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP). In this context, the meeting will also offer a particular opportunity to present the more

  9. Lessons Learned from Missing Flooding Barriers Operating Experience

    International Nuclear Information System (INIS)

    Simic, Z.; Veira, M. P.

    2016-01-01

    Flooding hazard is highly significant for nuclear power plant safety because of its potential for common cause impact on safety related systems, and because operating experience reviews regularly identify flooding as a cause of concern. Source of the flooding could be external (location) or internal (plant design). The amount of flooding water could vary but even small amount might suffice to affect redundant trains of safety related systems for power supply and cooling. The protection from the flooding is related to the design-basis flood level (DBFL) and it consists of three elements: structural, organizational and accessibility. Determination of the DBFL is critical, as Fukushima Daiichi accident terribly proved. However, as the topic of flooding is very broad, the scope of this paper is focused only on the issues related to the missing flood barriers. Structural measures are physically preventing flooding water to reach or damage safety related system, and they could be permanent or temporary. For temporary measures it is important to have necessary material, equipment and organizational capacity for the timely implementation. Maintenance is important for permanent protection and periodical review is important for assuring readiness and feasibility of temporary flooding protection. Final flooding protection element is assured accessibility to safety related systems during the flooding. Appropriate flooding protection is based on the right implementation of design requirements, proper maintenance and periodic reviews. Operating experience is constantly proving how numerous water sources and systems interactions make flooding protection challenging. This paper is presenting recent related operating experience feedback involving equipment, procedures and analysis. Most frequent deficiencies are: inadequate, degraded or missing seals that would allow floodwaters into safety related spaces. Procedures are inadequate typically because they underestimate necessary

  10. Experience Engineering: An Engineering Course for Non-Majors

    Science.gov (United States)

    Hargrove-Leak, Sirena

    2012-01-01

    The engineering profession continues to struggle to attract new talent, in part because it is not well understood by the general public and often viewed in a negative light. Therefore, engineering professionals have called for new approaches promote better understanding and change negative perceptions. One suggested approach is for engineering…

  11. Field tests on migration of TRU-nuclide, (2). Migration test for engineered barrier materials in aerated soil

    International Nuclear Information System (INIS)

    Maeda, Toshikatsu; Tanaka, Tadao; Mukai, Masayuki

    2003-01-01

    Field tests on migration of radionuclides for engineered barrier materials such as bentonite and cementitious materials were performed. The tests were run under both wet conditions with artificial rainfall and dry conditions with natural rainfall. Laboratory experiments such as batch adsorption tests were also conducted to analyze the result of field test. The results of field tests agreed with the predicted moisture conditions and the migration behaviors observed at the laboratory experiment that is reported so far. For bentonite material, the movements of the tracer were calculated using known information such as the results of batch sorption tests and migration mechanism. Comparing the result of field test and calculations, it is suggested that tracer migration behavior in bentonite material in field can be evaluated quantitatively by the known migration mechanism and the results of laboratory experiments such as batch sorption test. (author)

  12. Field studies of engineered barriers for closure of low level radioactive waste landfills at Los Alamos, New Mexico, USA

    International Nuclear Information System (INIS)

    Nyhan, J.W.; Langhorst, G.J.; Martin, C.E.; Martinez, J.L.; Schofield, T.G.

    1993-01-01

    The Los Alamos National Laboratory examined water balance relationships for four different landfill cover designs containing engineered barriers. These field experiments were performed at Los Alamos, New Mexico, USA, in 1.0- by 10.0-m plots with downhill slopes of 5, 10, 15, and 25%. Field measurements of seepage, precipitation, interflow, runoff, and soil water content were collected in each of the 16 plots representing four slopes each with four cover designs: Conventional, EPA, Loam Capillary Barrier and Clay Loam Capillary Barrier. A seepage collection system was installed beneath each cover design to evaluate the influence of slope length on seepage using a series of four metal pans filled with medium gravel that were placed end-to-end in the bottom of each field plot. An automated water flow data logging system was used to collect hourly seepage, interflow and runoff data and consisted of 100 100-liter tanks, each of which was equipped with an ultrasonic liquid-level sensor and a motor-operated ball valve used to drain the tank. Soil water content was routinely monitored every six hours at each of 212 locations throughout the 16 plots with time domain reflectrometry (TDR) techniques using an automated and multiplexed measurement system. Field data is presented to show the effects of slope and slope length on the performance of each landfill cover design for the first 15 months of this field experiment

  13. Summary report of research on evaluation of coupled thermo-hydro-mechanical behavior in the engineered barrier

    International Nuclear Information System (INIS)

    Chijimatsu, Masakazu; Amemiya, Kiyoshi; Yamashita, Ryo

    2002-02-01

    After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanisms, infiltration of groundwater from the surrounding rock in to the engineered barrier system, stress imposed by the overburden pressure and generation of swelling pressure in the buffer due to water infiltration. In order to recognize and evaluate these coupled thermo-hydro-mechanical (THM) phenomena, it is necessary to make a confidence of the mathematical models and computer codes. Evaluating these coupled THM phenomena is important in order to clarify the initial transient behavior of the EBS within the near field. DECOVALEX project is an international co-operative project for the DEvelopment of COupled models and their VALidation against EXperiments in nuclear waste isolation and it is significance to participate this project and to apply the code for the validation. Therefore, we tried to apply the developed numerical code against the subjects of DECOVALEX. In the above numerical code, swelling phenomenon is modeled as the function of water potential. However it dose no evaluate the experiment results enough. Then, we try to apply the new model. (author)

  14. First polarization-engineered compressively strained AlInGaN barrier enhancement-mode MISHFET

    International Nuclear Information System (INIS)

    Hahn, Herwig; Reuters, Ben; Wille, Ada; Ketteniss, Nico; Kalisch, Holger; Vescan, Andrei; Benkhelifa, Fouad; Ambacher, Oliver

    2012-01-01

    One current focus of research is the realization of GaN-based enhancement-mode devices. A novel approach for the realization of enhancement-mode behaviour is the utilization of polarization matching between the barrier and the GaN buffer. Yet, the utilization of a quaternary barrier combining polarization engineering together with a large conduction band offset has not been demonstrated so far. Here, epitaxially grown, compressively strained AlInGaN is applied as a nearly polarization-matched barrier layer on GaN resulting in enhancement-mode operation. The insulated-gate devices are fabricated gate-first with Al 2 O 3 as gate dielectric. Passivated metal insulator semiconductor heterostructure field effect transistors yielded threshold voltages (V th ) of up to +1 V. The devices withstand negative and positive gate-biased stress and a positive V th is maintained even after long-time negative bias stress. (paper)

  15. Investigation of the long term stability and corrosion resistance of engineering barriers

    International Nuclear Information System (INIS)

    Aoyama, Eri; Tachikawa, Hirokazu; Shimizu, Akihiko

    2005-03-01

    The Japan Nuclear Cycle Development Institute submitted 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' to the Japanese government. This report contains investigations of the long term behavior of alteration of bentonite, and of the corrosion life time of overpack on the basis of experimental data and past research, assuming the ranging geological environment of Japan. However some subjects, such as the behavior of the bentonite and overpack under high pH conditions and the behavior of the engineering barrier with change of near-field environmental condition with time for promoting reliability have still been left. To take into account these conditions, expert committees composed of clay science and metal corrosion science experts were established in the Nuclear Safety Research Association and past research outcomes and the theory of safety assessment were investigated from the view points of long term stability and corrosion resistance of engineering barrier. (author)

  16. Nonmetallic engineered barriers, their properties and role in a geologic repository for high level radioactive waste

    International Nuclear Information System (INIS)

    Lisy, F.

    1994-01-01

    The efficiency of engineered barrier systems depends to a great extent on the properties of the materials used. Backfill and sealing materials must fulfill certain requirements and criteria. They must feature low hydraulic conductivity, high retardation capacity, extremely good sorption properties for a wide range of radionuclides potentially leachable from the deposited waste, low permeability, good compatibility with engineered and natural barriers, good workability, and availability in the necessary quantity and at a reasonable price. Some basic properties are presented of materials which fulfill, to a considerable degree, these requirements and which are thus suggested as suitable backfills, sealings of buffers, namely clay- and cement-based materials (concretes, mortars, etc.). A brief information is also given on some other materials like bitumen, asphalt, etc. (Z.S.) 4 refs

  17. Assessment of Environmental Factors of Geology on Waste and Engineering Barriers for Waste Storage Near Surface

    International Nuclear Information System (INIS)

    Arimuladi SP

    2007-01-01

    Geological environment factors include features and processes occurring within that spatial and temporal (post-closure) domain whose principal effect is to determine the evolution of the physical, chemical, biological and human conditions of the domain that are relevant to estimating the release and migration of radionuclide and consequent exposure to man. Hardness of radioactive waste and engineer barrier can be decrease by environmental factors. Disposal system domain geological environment factors is a category in the International FEP list and is divided into sub-categories. There are 13 sub-factors of geological environment, 12 sub-factors influence hardness of radioactive waste and engineer barrier, thermal processes and conditions in geosphere can be excluded. (author)

  18. Experimental Studies of Engineered Barrier Systems Conducted at Los Alamos National Laboratory (FY16)

    Energy Technology Data Exchange (ETDEWEB)

    Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maner, James [Univ. of Oklahoma, Norman, OK (United States). School of Geology and Geophysics; Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Univ. of California, Los Angeles, CA (United States). Dept. of Earth, Planetary, and Space Sciences; Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-04

    Over the past five years the Used Fuel Campaign has investigated Engineered Barrier Systems (EBS) at higher heat loads (up to 300°C) and pressure (150 bar). This past year experimental work was hindered due to a revamping of the hydrothermal lab. Regardless, two experiments were run this past year, EBS-18 and EBS-19. EBS-18 was run using Low Carbon Steel (LCS) and opalinus clay in addition to the bentonite and opalinus brine. Many of the past results were confirmed in EBS-18, such as the restriction of illite formation due to the bulk chemistry, pyrite degradation, and zeolite formation dependent on the bentonite and opalinus clay. The LCS show vast amounts of pit corrosion (over 100μm of corrosion in six weeks), leading a corrosion rate of 1083 μm/year. In addition, a mineral goethite, an iron-bearing hydroxide, formed in the pits of the LCS. Preliminary results from EBS-19 water chemistry are included but SEM imaging, micro probe and XRD are still needed for further results. Copper corrosion was investigated further and over 850 measurements were taken. It was concluded that pitting and pyrite degradation drastically increase the corrosion rate from 0.12 to 0.39 μm/day. However, the growth of a layer of the mineral chalcocite is thought to subdue the corrosion rate to 0.024 μm/day as observed in the EBS-13, a sixth month experiment. This document presents the findings of this past year.

  19. Engineered barrier system and waste package design concepts for a potential geologic repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Short, D.W.; Ruffner, D.J.; Jardine, L.J.

    1991-10-01

    We are using an iterative process to develop preliminary concept descriptions for the Engineered Barrier System and waste-package components for the potential geologic repository at Yucca Mountain. The process allows multiple design concepts to be developed subject to major constraints, requirements, and assumptions. Involved in the highly interactive and interdependent steps of the process are technical specialists in engineering, metallic and nonmetallic materials, chemistry, geomechanics, hydrology, and geochemistry. We have developed preliminary design concepts that satisfy both technical and nontechnical (e.g., programmatic or policy) requirements

  20. Barriers to the Uptake of Concurrent Engineering in the Nigerian Construction Industry

    Directory of Open Access Journals (Sweden)

    Nathaniel Anny Aniekwu

    2012-12-01

    engineering and also to compute the Kendall’s coefficient of concordance, which assess the levels of agreement among the judges on the consistency of the rankings. A Kendall’s coefficient of concordance of W=0.57365 was recorded. A lack of awareness emerged as the most important barrier against the integration of this concept into the Nigerian construction industry. The top five variables are all human factors that can be ameliorated by proper education.

  1. Choice of french clays as engineered barrier components for waste disposal

    International Nuclear Information System (INIS)

    Coulon, H.; Lajudie, A.; Debrabant, P.; Atabek, R.; Jorda, M.; Andre-Jehan, R.

    1987-01-01

    Results are presented of physical measurements on candidate buffer materials for use in nuclear fuel waste disposal. The materials being considered as constituent elements of engineered barriers are essentially calcium smectite clays, in other terms swelling clays, coming from fourteen french deposits. The criteria for good candidates are mainly: smectite content in the clay materials, carbonate and organic material content and bulk density of the material, compacted under a pressure of 100 MPa. 14 references, 4 figures, 6 tables

  2. Assessment on mechanical effect of engineering barrier system to fault movement. Research document

    International Nuclear Information System (INIS)

    Hirai, Takashi; Tanai, Kenji; Takaji, Kazuhiko; Ohnuma, Satoshi

    2003-03-01

    The objective of this report is to clarify mechanical effect of engineering barrier system to the unavoidable fault movement. From the basic policy of the second progress report by JNC, natural phenomenon which affect strongly to the geological disposal system should be avoided. However, small faults as sliprate ''C'' far from principal fault zone, are difficult to be found out completely. Therefore, it is important to evaluate the influence of these fault movements and to clarify stability and safety of the engineered barrier system. Accordingly, the effect of a rock displacement across a deposition holl was considered and the midium scale test was carried out. Then midium scale test was simulated by Finit Element Method in which the constitutive model of Tresca was adopted to analyze elastoplastic behavior of buffer material. From the result of the midium scale test and the analysis, it was realized that the buffer material diminish shear stress acting on the overpack. Further analytical study was conducted to evaluate the real scale engineered barrier system designed in the second progress report by JNC. From the study, it was appeared that stress in buffer corresponded to the stress calculated for the midium scale test model. Consequently, it was obvious that rock displacement, 80% of buffer didn't affect overpack if velocity of fault movement was under 10 cm/sec. (author)

  3. The biofiltration permeable reactive barrier: Practical experience from Synthesia

    Energy Technology Data Exchange (ETDEWEB)

    Vesela, L.; Nemecek, J.; Siglova, M.; Kubal, M. [DEKONTA, Prague (Czech Republic)

    2006-10-15

    The paper refers to utilization of biological elements within permeable reactive barriers. The concept of a biofiltration permeable barrier has been tested in the laboratory and in pilot-scale. Oxyhumolite (oxidized young lignite) was examined as an absorption material and a biofilm carrier. Laboratory tests performed before the pilot verification confirmed that oxyhumolite adsorbs organic pollutants at a minimum value, but that it can be used for biofilm attachment. An experimental barrier was built on premises of a chemical factory contaminated mainly by various organic pollutants (benzene, toluene, ethylbenzene, and xylenes (BTEX), chlorobenzenes, naphthalene, nitro-derivatives, phenols, trichloroethylene (TCE), and total petroleum hydrocarbon (TPH)). Before the barrier was installed, a preliminary survey of the unsaturated zone, hydrogeological investigation, and a microbiological survey had been performed. The barrier was designed as a trench-and-gate system with an in situ bioreactor. During the year 2004, measurements of groundwater flux and retention time under current hydrological conditions, together with chemical and microbiological monitoring, were carried out on the site. The results showed high effectiveness of organic contamination removal. Average elimination varied from 57.3% (naphthalene) to 99.9% (nitro-derivatives, BTEX); microbial density in the bioreactor was approx. 10{sup 5} CFU mL{sup -1}.

  4. Backfill barriers: the use of engineered barriers based on geologic materials to assure isolation of radioactive wastes in a repository. [Nickel-iron alloys

    Energy Technology Data Exchange (ETDEWEB)

    Apps, J.A.; Cook, N.G.W.

    1981-06-01

    A preliminary assessment is made to show that canisters fabricated of nickel-iron alloys, and surrounded by a suitable backfill, may produce an engineered barrier where the canister material is thermodynamically stable with respect to its environment. As similar conditions exist in nature, the performance of such systems as barriers to isolate radionuclides can be predicted over very long periods, of the order of 10/sup 6/ years.

  5. Investigation of students' experiences of gendered cultures in engineering workplaces

    Science.gov (United States)

    Male, Sally A.; Gardner, Anne; Figueroa, Eugenia; Bennett, Dawn

    2018-05-01

    Women remain severely under-represented in engineering in Australia as in all Western countries. This limits the pool of talent, standpoints and approaches within the profession. Furthermore, this under-representation equates to restriction of the benefits of being an engineer mainly to men. Gendered workplace experiences have been found to contribute to women leaving the profession. In this study we explore students' experiences of gendered cultures in engineering workplaces, using interviews with a purposive sample of 13 students (4 male) recruited following a previous survey. Although the overall experience of workplace learning is positive for many students, male and female engineering students reported experiences consistent with masculine cultures. Educators and employers must proactively lead improvements to the culture in engineering workplaces, prepare students for gendered workplaces and support students to reflect during and after workplace experiences. The experiences presented here could be adapted to enhance inclusivity training.

  6. Engineered barrier construction in salt rock. Final report of project phase 2. Period covered: 1 July 1989 - 31 December 1992

    International Nuclear Information System (INIS)

    Stockmann, N.; Beinlich, A.; Droste, J.; Flach, D.; Glaess, F.; Jockwer, N.; Krogmann, P.; Miehe, R.; Moeller, J.; Schwaegermann, F.; Wallmueller, R.; Walter, F.; Yaramanci, U.

    1994-01-01

    The project report presents and explains data obtained by a specific measuring programme, giving evidence of the sealing efficiency of an engineered barrier comprising abutment, long-term barrier, and hydraulic short-term barrier, the sealing performance having been verified for shorter and longer periods of time ( up to approx. 500 years). Specific computer codes have been applied for computing and verifying the long-term efficiency of the complex engineered barrier system (artificial structures and surrounding rock). The technical feasibility and the performance of an engineered barrier for reliable sealing of a radwaste repository is thus demonstrated at a scale of 1:1 at the site of the Asse mine [de

  7. Demonstration Experiments with a Stirling Engine.

    Science.gov (United States)

    Deacon, Christopher G.; And Others

    1994-01-01

    Describes an investigation with the primary purpose of allowing students to generate and interpret a pressure/volume diagram of a Stirling engine. Explains how the Stirling engine can be used to demonstrate the principles of operation of a refrigerator and a heat pump. (DDR)

  8. FAILURE MECHANISMS OF THERMAL BARRIER COATINGS INTERNAL COMBUSTION ENGINES AND llMPROVEMENTS

    Directory of Open Access Journals (Sweden)

    ADNAN PARLAK

    2003-04-01

    Full Text Available MechanicaJ properties of high performance ceramics have been improved to the point where their use in heat engines is possible. The high temperature strength and low thermal expansion properties of bigh performance ceramics offer an advantage over metals in the development of non-water cooling engine. However, because bard environment in diesel engine combustion chamber, solving the problem of durabiUty of TBC is important. DurabiUty of thermal barrier coatings(TBC is liınited by two main failure mechanisms: Therınal expansion nlİsmatch betwcen bond coat and top coat and bond coat oxidation. Both of these can cause failure of the ceramic top coat. Developments of recent years sholv that bond coats \\Vith higher oxidation resistance tend to have better coating system cyclic lives

  9. Dissolution characteristics of chalcedony under alkaline condition. Study for changes in mineral composition of engineered barrier composed by bentonite

    International Nuclear Information System (INIS)

    Watanabe, Yasutaka; Yokoyama, Shingo

    2016-01-01

    In the engineered barrier of radioactive waste disposal facilities, it is expected that bentonite is exposed to alkaline groundwater which arise from leaching of cementations materials. Minerals contained in the bentonite will be dissolved by reactions of the alkaline groundwater. Some bentonite contains silica such as quartz and chalcedony. Chalcedony is categorized in intermediate silica which is microcrystalline. It is known that dissolution of silica influences to the dissolution of smectite by means of solubility. However, dissolution kinetics of chalcedony in the alkaline condition has not been investigated, which is an uncertainty in geochemical simulations to evaluate a long-term stability of the engineered barrier. Therefore, this study performed flow-through experiments in alkaline conditions using chalcedony in order to obtain the dissolution rate of the chalcedony. The flow-through experiments was performed using NaOH-NaCl solution adjusted to 0.3 mol/L of ionic strength. Initial pH of the solution was from 8.9 to 13.5. As a result, higher pH and higher temperature showed higher Si ion concentrations of reacted solutions. The dissolution rate of the samples was calculated using Si ion concentrations at steady state of the experiment. Note that, the dissolution rate of the chalcedony was almost same as that of quartz at same temperature. After the experiments, SEM observation showed that rough surface of the chalcedony partly changed to smooth surface like quartz. It is supposed that rough surface of chalcedony was rapidly dissolved because of low degree of crystallization. The dissolution rate obtained is supposedly applicable to highly crystalline SiO 2 of chalcedony. (author)

  10. Study of waterproof capabilities of the engineered barrier containing bentonite in near surface radioactive waste repositories

    International Nuclear Information System (INIS)

    Luu Cao Nguyen; Nguyen Ba Tien; Doan Thi Thu Hien; Nguyen Van Chinh; Vuong Huu Anh

    2017-01-01

    In Vietnam, the study of nuclear fuel cycle is in first steps, such as the exploitation and uranium processing. These processes generated large amounts of radioactive waste over-timing. The naturally occurring radioactive material and technologically enhanced radioactive material (NORM/TENORM) waste, which would be large, needs to be managed and disposed reasonably by effective methods. These wastes were used to be disposal in the near surface. It was therefore very important to study the model of radioactive waste repository, where bentonite waterproofing layer would be applied for the engineered barrier. The aim of this study was to obtain the preliminary parameters for low-level radioactive waste disposal site being suitable with the conditions of Vietnam. The investigation of the ratio between soil and bentonite was taken part. The experiments with some layers of waterproofing material with the ratio of soil and bentonite as 75/25, 50/50 and 25/75 were carried out to test the moving of uranium nuclide through these waterproofing material layers. Analyzing the uranium content in each layer (0.1 cm) of pressed soil - bentonite mixture (as a block) to determine the uranium nuclide adsorption from solution into the materials in the different ratios at the different times: 1, 2 and 3 months was carried out. The results showed that the calculated average rate of uranium nuclide migration into the soil - bentonite layer was 5.4x10 -10 , 5.4x10 -10 and 3.85x10 -10 m/s corresponding to the waterproofing layer thickness (for 300 years) 4.86 m, 4.86 m and 3.63 m respectively, which was due on the ratio of soil and bentonite 75/25, 50/50, 25/75 to keep the safety for the repository. (author)

  11. Renewable Energy Permitting Barriers in Hawaii: Experience from the Field

    Energy Technology Data Exchange (ETDEWEB)

    Busche, S.; Donnelly, C.; Atkins, D.; Fields, R.; Black, C.

    2013-03-01

    This white paper presents a summary of the solicited input from permitting agencies and renewable energy developers on the permitting process in Hawaii to provide stakeholders in Hawaii, particularly those involved in permitting, with information on current permitting barriers that renewable energy developers are experiencing.

  12. Studies on an advanced repository system with enhanced engineered barriers (a framework)

    International Nuclear Information System (INIS)

    Fujiwara, A.; Tashiro, S.; Ikari, S.; Suzuki, A.

    1993-01-01

    In order to propose advanced designs of repositories with enhanced engineered barriers of relatively high radioactive wastes such as burnable poisons, channel boxes, control rods and highly irradiated metals, studies started in 1987 and completed the first phase in 1992. This paper presents the framework and brief results of the first phase. The studies set preliminary design concepts of the repositories with various combinations with engineered barriers and natural barriers for different models and locations such as a silo type in shallow land or a tunnel type in intermediate depth. Through the designs, four component technics were picked up and studied for (1) construction of the components in repository; (2) performance evaluation to realize repository design; (3) improvement of circumstances inside or around repository; and (4) surveillance of repository performance to realize the repository designs. Finally, some repository systems were provided using obtained results, and then the applicability and the economy were evaluated. The studies will continue to the second phase focusing on the long-term performance of the repositories

  13. Monitoring long-term evolution of engineered barrier systems using magnets: Magnetic response.

    Science.gov (United States)

    Rigonat, N; Isnard, O; Harley, S L; Butler, I B

    2018-01-05

    Remote and non-destructive monitoring of the stability and performance of Engineered Barrier Systems for Geological Disposal Facility of is gaining considerable importance in establishing the safety cases for Higher Activity Wastes disposal. This study offers an innovative use of mineral magnetism for monitoring groundwater saturation of the barrier. Four mixtures of permanent magnets (Nd-Fe-B, coated and uncoated; SmCo and AlNiCo) and bentonite were reacted for 4, 8 and 12 months with mildly-saline, high-pH leachates, representing the fluids saturating a time-evolved engineered barrier. Coupled hysteresis and thermomagnetic analyses demonstrate how Nd-Fe-B feature a time-dependent transition from square-like ferromagnetic to superparamagnetic loop via pot-bellied and wasp-waist loops, whereas SmCo and AlNiCo do not show so extensive corrosion-related variations of the intrinsic and extrinsic magnetic properties. This study allowed to identify magnetic materials suitable for shorter- (Nd-Fe-B) and longer-term (SmCo and AlNiCo) monitoring purposes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Temperature effect on the behaviour of engineered clay barriers; Effet de la temperature sur le comportement des barrieres de confinement

    Energy Technology Data Exchange (ETDEWEB)

    Tang, A.M

    2005-11-15

    The present work deals with the thermo-hydro-mechanical behaviour of compacted swelling clay used for engineered barriers in high-level radioactive repositories. The MX80 bentonite was chosen for this work. Firstly, an experimental work on the thermal conductivity of the compacted bentonite was performed. The results evidenced the effects of dry density, water content, volumetric fraction of soil components, microstructure, and mineralogy. This experimental work gave rise to the proposition of a theoretical model for estimate the thermal conductivity of compacted bentonites. Secondly, after a calibration of suction generated by saturated saline solution in function of temperature, water retention curves were determined at different temperatures. The experimental results showed a decrease of the water retention capacity of soil after heating. A simple model based on the interfacial tension air-water was formulated to simulate this effect. Thirdly, a new isotropic cell enabling a simultaneous control of suction, temperature and mechanical stress was developed. With this new cell, an experimental work on the thermo-mechanical behaviour of the unsaturated compacted bentonite was performed. Finally, a constitutive model was developed for simulate the thermo-hydro-mechanical behaviours obtained experimentally. (author)

  15. Investigating the Potential Barrier Function of Nanostructured Materials Formed in Engineered Barrier Systems (EBS) Designed for Nuclear Waste Isolation.

    Science.gov (United States)

    Cuevas, Jaime; Ruiz, Ana Isabel; Fernández, Raúl

    2018-02-21

    Clay and cement are known nano-colloids originating from natural processes or traditional materials technology. Currently, they are used together as part of the engineered barrier system (EBS) to isolate high-level nuclear waste (HLW) metallic containers in deep geological repositories (DGR). The EBS should prevent radionuclide (RN) migration into the biosphere until the canisters fail, which is not expected for approximately 10 3  years. The interactions of cementitious materials with bentonite swelling clay have been the scope of our research team at the Autonomous University of Madrid (UAM) with participation in several European Union (EU) projects from 1998 up to now. Here, we describe the mineral and chemical nature and microstructure of the alteration rim generated by the contact between concrete and bentonite. Its ability to buffer the surrounding chemical environment may have potential for further protection against RN migration. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Application of engineered sorbent barriers Summary of Laboratory Data for FY 1988

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Jones, E.O.

    1989-09-01

    Laboratory studies were conducted in FY 1988 Pacific Northwest Laboratory to determine the effect of contact time, pH, solution to solid ratio, and particle size on the performance of a number of materials in adsorbing radioactive cobalt, strontium, and cesium. The laboratory studies were conducted to provide background information useful in designing an engineered sorbent barrier, which restricts the migration of radionuclides from low-level waste sites. Understanding how the variables affect the adsorption of ions on the sorbent materials is the key to estimating the performance of sorbent barriers under a variety of conditions. The scope of the studies was limited to three radionuclides and four sorbent materials, but the general approach can be used to evaluate other radionuclides and conditions. The sorbent materials evaluated in this study included clinoptilolite, activated carbon, bentonite clay, and Savannah River soil. The clinoptilolite and activated carbon were identified in previous studies as the most cost-effective materials for sorption of the three radionuclides under consideration. The bentonite clay was evaluated as a component of the barrier that could be used to modify the permeability of the barrier system. The Savannah River soil was used to represent soil from a humid site. 3 refs., 14 figs., 1 tab.

  17. Engineering an in vitro air-blood barrier by 3D bioprinting

    Science.gov (United States)

    Horváth, Lenke; Umehara, Yuki; Jud, Corinne; Blank, Fabian; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2015-01-01

    Intensive efforts in recent years to develop and commercialize in vitro alternatives in the field of risk assessment have yielded new promising two- and three dimensional (3D) cell culture models. Nevertheless, a realistic 3D in vitro alveolar model is not available yet. Here we report on the biofabrication of the human air-blood tissue barrier analogue composed of an endothelial cell, basement membrane and epithelial cell layer by using a bioprinting technology. In contrary to the manual method, we demonstrate that this technique enables automatized and reproducible creation of thinner and more homogeneous cell layers, which is required for an optimal air-blood tissue barrier. This bioprinting platform will offer an excellent tool to engineer an advanced 3D lung model for high-throughput screening for safety assessment and drug efficacy testing. PMID:25609567

  18. Permeable barrier materials for strontium immobilization: Unsaturated flow apparatus determination of hydraulic conductivity -- Column sorption experiments

    International Nuclear Information System (INIS)

    Moody, T.E.; Conca, J.

    1996-09-01

    Selected materials were tested to emulate a permeable barrier and to examine the (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium (Cr 6+ ) in Hanford Site groundwater; and (2) hydraulic conductivity of the barrier material relative to the surrounding area. The emplacement method investigated was a permeable reactive barrier to treat contaminated groundwater as it passes through the barrier. The hydraulic conductivity function was measured for each material, and retardation column experiments were performed for each material. Measurements determining the hydraulic conductivity at unsaturated through saturated water content were executed using the Unsaturated Flow Apparatus

  19. DTR, Taut Wire System: An alarm barrier with experience

    International Nuclear Information System (INIS)

    Kraft, A.J.

    1986-01-01

    The Taut Wire Fence Alarm System concept was developed and introduced more that fifteen years ago in Israel. A sudden expansion of the nations's border lines, the difficulty to monitor intrusions along those elongated lines and the need for timely as well as accurate armed response to an intrusion attempt dictated the need for an alarming barrier. Traditionally, protection of perimeters was accomplished by the installation of a fence or other type obstacles (man made or natural) and surveillance by manned patrols, fixed observation posts, and/or electronic devices. Defense planners recognized therefore the need for an alarming barrier. A concentrated effort by scientists solved the problem by developing the first Taut Wire Fence Alarm System in a configuration of an alarm barrier. The system was specified to have an extremely low false alarm rate (FAR/NAR), high probability of detection, the capability to follow various terrains, operability in a wide range of environmental conditions, a capability to delay an intruder, ease of installation by unskilled labor, and low maintenance requirements. The authors try here to explain the various constraints and considerations given during the design stages of the Taut Wire Alarm System so as to bring the present magnitude of users to a better understanding of the system's operation

  20. Assessment of the Effectiveness of Clay Soil Covers as Engineered Barriers in Waste Disposal Facilities with Emphasis on Modeling Cracking Behavior

    Science.gov (United States)

    2008-06-01

    standard proctor hammer (ASTM D698), which was dropped a sufficient number of times to achieve the desired dry density ERDC TR-08-7 34 Figure...using a standard proctor hammer to an equivalent dry density as was found in Experiment 1. ERDC TR-08-7 45 Figure 25. Sample container for...ER D C TR -0 8- 7 Assessment of the Effectiveness of Clay Soil Covers as Engineered Barriers in Waste Disposal Facilities with Emphasis

  1. Test Plan to Assess Fire Effects on the Function of an Engineered Surface Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Anderson L.; Berlin, Gregory T.; Cammann, Jerry W.; Leary, Kevin D.; Link, Steven O.

    2008-09-29

    Wildfire is a frequent perturbation in shrub steppe ecosystems, altering the flora, fauna, atmosphere, and soil of these systems. Research on the fire effects has focused mostly on natural ecosystems with essentially no attention on engineered systems like surface barriers. The scope of the project is to use a simulated wildfire to induce changes in an engineered surface barrier and document the effects on barrier performance. The main objective is to quantify the effects of burning and the resulting post-fire conditions on alterations in soil physical properties; hydrologic response, particularly the water balance; geochemical properties; and biological properties. A secondary objective is to use the lessons learned to maximize fire protection in the design of long-term monitoring systems based on electronic sensors. A simulated wildfire will be initiated, controlled and monitored at the 200-BP-1 barrier in collaboration with the Hanford Fire Department during the fall of 2008. The north half of the barrier will be divided into nine 12 x 12 m plots, each of which will be randomly assigned a fuel load of 2 kg m-2 or 4 kg m-2. Each plot will be ignited around the perimeter and flames allowed to carry to the centre. Any remaining unburned vegetation will be manually burned off using a drip torch. Progress of the fire and its effects will be monitored using point measurements of thermal, hydrologic, and biotic variables. Three measures of fire intensity will be used to characterize fire behavior: (1) flame height, (2) the maximum temperature at three vertical profile levels, and (3) total duration of elevated temperature at these levels. Pre-burn plant information, including species diversity, plant height, and canopy diameter will be measured on shrubs from the plots to be burned and from control plots at the McGee ranch. General assessments of shrub survival, recovery, and recruitment will be made after the fire. Near-surface soil samples will be collected pre- and

  2. Test Plan to Assess Fire Effects on the Function of an Engineered Surface Barrier

    International Nuclear Information System (INIS)

    Ward, Anderson L.; Berlin, Gregory T.; Cammann, Jerry W.; Leary, Kevin D.; Link, Steven O.

    2008-01-01

    Wildfire is a frequent perturbation in shrub steppe ecosystems, altering the flora, fauna, atmosphere, and soil of these systems. Research on the fire effects has focused mostly on natural ecosystems with essentially no attention on engineered systems like surface barriers. The scope of the project is to use a simulated wildfire to induce changes in an engineered surface barrier and document the effects on barrier performance. The main objective is to quantify the effects of burning and the resulting post-fire conditions on alterations in soil physical properties; hydrologic response, particularly the water balance; geochemical properties; and biological properties. A secondary objective is to use the lessons learned to maximize fire protection in the design of long-term monitoring systems based on electronic sensors. A simulated wildfire will be initiated, controlled and monitored at the 200-BP-1 barrier in collaboration with the Hanford Fire Department during the fall of 2008. The north half of the barrier will be divided into nine 12 x 12 m plots, each of which will be randomly assigned a fuel load of 2 kg m-2 or 4 kg m-2. Each plot will be ignited around the perimeter and flames allowed to carry to the centre. Any remaining unburned vegetation will be manually burned off using a drip torch. Progress of the fire and its effects will be monitored using point measurements of thermal, hydrologic, and biotic variables. Three measures of fire intensity will be used to characterize fire behavior: (1) flame height, (2) the maximum temperature at three vertical profile levels, and (3) total duration of elevated temperature at these levels. Pre-burn plant information, including species diversity, plant height, and canopy diameter will be measured on shrubs from the plots to be burned and from control plots at the McGee ranch. General assessments of shrub survival, recovery, and recruitment will be made after the fire. Near-surface soil samples will be collected pre- and

  3. Quantification of Cation Sorption to Engineered Barrier Materials Under Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Powell, Brian [Clemson Univ., SC (United States); Schlautman, Mark [Clemson Univ., SC (United States); Rao, Linfeng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nitsche, Heino [Univ. of California, Berkeley, CA (United States); Gregorich, Kenneth [Univ. of California, Berkeley, CA (United States)

    2016-02-02

    The objective of this research is to examine mechanisms and thermodynamics of actinide sorption to engineered barrier materials (iron (oxyhydr)oxides and bentonite clay) for nuclear waste repositories under high temperature and high ionic strength conditions using a suite of macroscopic and microscopic techniques which will be coupled with interfacial reaction models. Gaining a mechanistic understanding of interfacial processes governing the sorption/sequestration of actinides at mineral-water interfaces is fundamental for the accurate prediction of actinide behavior in waste repositories. Although macroscale sorption data and various spectroscopic techniques have provided valuable information regarding speciation of actinides at solid-water interfaces, significant knowledge gaps still exist with respect to sorption mechanisms and the ability to quantify sorption, particularly at high temperatures and ionic strengths. This objective is addressed through three major tasks: (1) influence of oxidation state on actinide sorption to iron oxides and clay minerals at elevated temperatures and ionic strengths; (2) calorimetric titrations of actinide-mineral suspensions; (3) evaluation of bentonite performance under repository conditions. The results of the work will include a qualitative conceptual model and a quantitative thermodynamic speciation model describing actinide partitioning to minerals and sediments, which is based upon a mechanistic understanding of specific sorption processes as determined from both micro-scale and macroscale experimental techniques. The speciation model will be a thermodynamic aqueous and surface complexation model of actinide interactions with mineral surfaces that is self-consistent with macroscopic batch sorption data, calorimetric and potentiometric titrations, X-ray absorption Spectroscopy (XAS, mainly Extended X-ray Absorption Fine Structure (EXAFS)), and electron microscopy analyses. The novelty of the proposed work lies largely in

  4. Quantification of Cation Sorption to Engineered Barrier Materials Under Extreme Conditions

    International Nuclear Information System (INIS)

    Powell, Brian; Schlautman, Mark; Rao, Linfeng; Nitsche, Heino; Gregorich, Kenneth

    2016-01-01

    The objective of this research is to examine mechanisms and thermodynamics of actinide sorption to engineered barrier materials (iron (oxyhydr)oxides and bentonite clay) for nuclear waste repositories under high temperature and high ionic strength conditions using a suite of macroscopic and microscopic techniques which will be coupled with interfacial reaction models. Gaining a mechanistic understanding of interfacial processes governing the sorption/sequestration of actinides at mineral-water interfaces is fundamental for the accurate prediction of actinide behavior in waste repositories. Although macroscale sorption data and various spectroscopic techniques have provided valuable information regarding speciation of actinides at solid-water interfaces, significant knowledge gaps still exist with respect to sorption mechanisms and the ability to quantify sorption, particularly at high temperatures and ionic strengths. This objective is addressed through three major tasks: (1) influence of oxidation state on actinide sorption to iron oxides and clay minerals at elevated temperatures and ionic strengths; (2) calorimetric titrations of actinide-mineral suspensions; (3) evaluation of bentonite performance under repository conditions. The results of the work will include a qualitative conceptual model and a quantitative thermodynamic speciation model describing actinide partitioning to minerals and sediments, which is based upon a mechanistic understanding of specific sorption processes as determined from both micro-scale and macroscale experimental techniques. The speciation model will be a thermodynamic aqueous and surface complexation model of actinide interactions with mineral surfaces that is self-consistent with macroscopic batch sorption data, calorimetric and potentiometric titrations, X-ray absorption Spectroscopy (XAS, mainly Extended X-ray Absorption Fine Structure (EXAFS)), and electron microscopy analyses. The novelty of the proposed work lies largely in

  5. Engineered barrier systems and canister orientation studies for the Yucca Mountain Project, Nevada

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1990-07-01

    Emplacement borehole orientation directly impacts many aspects of the Engineered Barrier System (EBS) and interactions with the near field environment. This paper considers the impacts of orientation on the hydrologic portion of the environment and its interactions with the EBS. The hydrologic environments is considered from a conceptual standpoint, the numerical analyses are left for subsequent work. As reported in this paper, several aspects of the hydrological environment are more favorable for long term performance of vertically oriented rather than horizontally oriented Waste Packages. 19 refs., 15 figs

  6. Waste form performance assessment in the YUCCA Mountain engineered barrier system, American Nuclear Society

    International Nuclear Information System (INIS)

    Morris, E. E.; Fanning, T. H.; Wigeland, R. A.

    2000-01-01

    This work demonstrates a technique for comparing the performance of waste forms in a repository environment when one or more of the waste forms constitute a small part of the total amount of waste planned for the repository. In applying the technique, it is important to identify radionuclides that are highly soluble in the transport fluid since it is only for these that the release is controlled by the dissolution rate of the waste form matrix. The techniques presented here have been applied to an evaluation of the performance of waste forms from the electrometallurgical treatment of spent fuel in the proposed Yucca Mountain Repository Engineered Barrier System (EBS)

  7. Examining E-Learning Barriers as Perceived by Faculty Members of Engineering Colleges in the Jordanian Universities

    Science.gov (United States)

    Al-Alawneh, Muhammad K.

    2014-01-01

    Employing computer's technology that includes e-learning system in the field of Engineering is a vital issue which needs to be discussed. Therefore, this study purposed to examine e-learning barriers as perceived by faculty members of engineering in three major universities in Jordan (Yarmouk University, Jordan University of Science and…

  8. Identifying the Barriers upon Development of Virtual Education in Engineering Majors (Case Study: The University of Isfahan)

    Science.gov (United States)

    Nikoonezhad, Sepideh; Nili, Mohammadreza; Esfahani, Ahmadreza Nasr

    2015-01-01

    The present study aims at investigating barriers upon development of virtual education in engineering majors at the University of Isfahan. The study has applied a mixed method (qualitative and quantitative) and its population consists all of the department members of the technical and engineering majors at the University of Isfahan including 125…

  9. Investigation and technical reviews of the long term stability and corrosion resistance of engineering barriers

    International Nuclear Information System (INIS)

    Tachikawa, Hirokazu

    2004-03-01

    The Japan Nuclear Fuel Cycle Development Institute submitted 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' to the Japanese government. This report contains investigations of the long term behavior of alteration of bentonite, and of the corrosion life time of overpack on the basis of experimental data and past research, assuming the ranging geological environment of Japan. However some subjects, such as the behavior of the bentonite and overpack under high pH conditions and the behavior of the engineering barrier with change of near-field environmental condition with time for promoting reliability have still been left. To take into account these conditions, expert committees composed of clay science and metal corrosion science experts were established in the Nuclear Safety Research Association and past research outcomes and the theory of safety assessment were investigated and technically reviewed from the view points of long term stability and corrosion resistance of engineering buffer materials. (author)

  10. Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture.

    Science.gov (United States)

    Karthikeya Sharma, T

    2015-11-01

    Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE). This paper investigates the effects of using argon (Ar) gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine's performance within the range studied.

  11. Experiment-Based Teaching in Advanced Control Engineering

    Science.gov (United States)

    Precup, R.-E.; Preitl, S.; Radac, M.-B.; Petriu, E. M.; Dragos, C.-A.; Tar, J. K.

    2011-01-01

    This paper discusses an experiment-based approach to teaching an advanced control engineering syllabus involving controlled plant analysis and modeling, control structures and algorithms, real-time laboratory experiments, and their assessment. These experiments are structured around the representative case of the longitudinal slip control of an…

  12. Barriers and strategies for the clinical translation of advanced orthopaedic tissue engineering protocols.

    Science.gov (United States)

    Madry, H; Alini, M; Stoddart, M J; Evans, C; Miclau, T; Steiner, S

    2014-05-06

    Research in orthopaedic tissue engineering has intensified over the last decade and new protocols continue to emerge. The clinical translation of these new applications, however, remains associated with a number of obstacles. This report highlights the major issues that impede the clinical translation of advanced tissue engineering concepts, discusses strategies to overcome these barriers, and examines the need to increase incentives for translational strategies. The statements are based on presentations and discussions held at the AO Foundation-sponsored symposium "Where Science meets Clinics 2013" held at the Congress Center in Davos, Switzerland, in September, 2013. The event organisers convened a diverse group of over one hundred stakeholders involved in clinical translation of orthopaedic tissue engineering, including scientists, clinicians, healthcare industry professionals and regulatory agency representatives. A major point that emerged from the discussions was that there continues to be a critical need for early trans-disciplinary communication and collaboration in the development and execution of research approaches. Equally importantly was the need to address the shortage of sustained funding programs for multidisciplinary teams conducting translational research. Such detailed discussions between experts contribute towards the development of a roadmap to more successfully advance the clinical translation of novel tissue engineering concepts and ultimately improve patient care in orthopaedic and trauma surgery.

  13. Barriers and strategies for the clinical translation of advanced orthopaedic tissue engineering protocols

    Directory of Open Access Journals (Sweden)

    H Madry

    2014-05-01

    Full Text Available Research in orthopaedic tissue engineering has intensified over the last decade and new protocols continue to emerge. The clinical translation of these new applications, however, remains associated with a number of obstacles. This report highlights the major issues that impede the clinical translation of advanced tissue engineering concepts, discusses strategies to overcome these barriers, and examines the need to increase incentives for translational strategies. The statements are based on presentations and discussions held at the AO Foundation-sponsored symposium "Where Science meets Clinics 2013" held at the Congress Center in Davos, Switzerland, in September, 2013. The event organisers convened a diverse group of over one hundred stakeholders involved in clinical translation of orthopaedic tissue engineering, including scientists, clinicians, healthcare industry professionals and regulatory agency representatives. A major point that emerged from the discussions was that there continues to be a critical need for early trans-disciplinary communication and collaboration in the development and execution of research approaches. Equally importantly was the need to address the shortage of sustained funding programs for multidisciplinary teams conducting translational research. Such detailed discussions between experts contribute towards the development of a roadmap to more successfully advance the clinical translation of novel tissue engineering concepts and ultimately improve patient care in orthopaedic and trauma surgery.

  14. Clinical Engineering: Experiences of assisted professional practices

    International Nuclear Information System (INIS)

    Langone, Luis; Vanetta, Marcos; Vazquez, Marcelo; Rotger, Viviana I; Olivera, Juan Manuel

    2007-01-01

    In the curricula of the Biomedical Engineering career of the Facultad de Ciencias Exactas y TecnologIa of the Universidad Nacional de Tucuman, Argenitna, there are the Assisted Professional Practices. Within this framework, the students have the possibility of performing practices in the clinic Sanatorio 9 de Julio. One of the objectives of these practices is to apply the concepts, methods and procedures studied along the career in the field work under real work conditions. From the point of view of the host institution, the objective is to improve the performance of the different services and areas applying the tools of Biomedical Engineering. The present work shows an example of such practices where an equipment preliminary analysis was made, its use and maintenance corresponding to the surgical unit of the clinic

  15. Sustainability in Design Engineering Education; Experiences in Northern Europe

    NARCIS (Netherlands)

    Dewulf, K.; Wever, R.; Boks, C.; Bakker, C.; D'hulster, F.

    2009-01-01

    In recent years, the implementation of sustainability into the curricula of engineering has become increasingly important. This paper focuses on the experiences of integrating sustainability in Design Engineering education in the academic bachelor programs at Delft University of Technology in The

  16. Women Engineering Transfer Students: The Community College Experience

    Science.gov (United States)

    Patterson, Susan J.

    2011-01-01

    An interpretative philosophical framework was applied to a case study to document the particular experiences and perspectives of ten women engineering transfer students who once attended a community college and are currently enrolled in one of two university professional engineering programs. This study is important because women still do not earn…

  17. Building a Framework for Engineering Design Experiences in High School

    Science.gov (United States)

    Denson, Cameron D.; Lammi, Matthew

    2014-01-01

    In this article, Denson and Lammi put forth a conceptual framework that will help promote the successful infusion of engineering design experiences into high school settings. When considering a conceptual framework of engineering design in high school settings, it is important to consider the complex issue at hand. For the purposes of this…

  18. Bacterial Diversity in Bentonites, Engineered Barrier for Deep Geological Disposal of Radioactive Wastes.

    Science.gov (United States)

    Lopez-Fernandez, Margarita; Cherkouk, Andrea; Vilchez-Vargas, Ramiro; Jauregui, Ruy; Pieper, Dietmar; Boon, Nico; Sanchez-Castro, Ivan; Merroun, Mohamed L

    2015-11-01

    The long-term disposal of radioactive wastes in a deep geological repository is the accepted international solution for the treatment and management of these special residues. The microbial community of the selected host rocks and engineered barriers for the deep geological repository may affect the performance and the safety of the radioactive waste disposal. In this work, the bacterial population of bentonite formations of Almeria (Spain), selected as a reference material for bentonite-engineered barriers in the disposal of radioactive wastes, was studied. 16S ribosomal RNA (rRNA) gene-based approaches were used to study the bacterial community of the bentonite samples by traditional clone libraries and Illumina sequencing. Using both techniques, the bacterial diversity analysis revealed similar results, with phylotypes belonging to 14 different bacterial phyla: Acidobacteria, Actinobacteria, Armatimonadetes, Bacteroidetes, Chloroflexi, Cyanobacteria, Deinococcus-Thermus, Firmicutes, Gemmatimonadetes, Planctomycetes, Proteobacteria, Nitrospirae, Verrucomicrobia and an unknown phylum. The dominant groups of the community were represented by Proteobacteria and Bacteroidetes. A high diversity was found in three of the studied samples. However, two samples were less diverse and dominated by Betaproteobacteria.

  19. Execution techniques for high level radioactive waste disposal. 4. Design and manufacturing procedure of engineered barriers

    International Nuclear Information System (INIS)

    Ogata, Nobuhide; Kosaki, Akio; Ueda, Hiroyoshi; Asano, Hidekazu; Takao, Hajime

    1999-01-01

    Ensuring the physical integrity of engineered barriers for an extremely long time period is necessary for geological disposal of high-level radioactive wastes. This report describes the design process and the designed configurations of both overpack and buffer as engineered barriers. Manufacturing procedure, quality control and inspection methods are also summarized. Carbon steel was selected as a structural material of the overpack and the specification of the overpack was determined assuming disposal in the depths of 1000 m below surface of crystalline rock site. The mixture of bentonite and sand (80% sodium bentonite and 20% silica sand by mass) was selected as material for a buffer from mainly its permeability and characteristics of self-sealing of a gap occurred in construction work. Welding method of a lid onto the main body of the overpack, uniting method of a corrosion-resistance layer and the structural component in the case of a composite overpack and manufacturing procedures of both blocks-type and monolithic-type buffers are also investigated. (author)

  20. Croatian Experience in Road Traffic Noise Management - Concrete Noise Barriers

    Directory of Open Access Journals (Sweden)

    Ahac Saša

    2014-07-01

    Full Text Available The paper gives an overview of concrete noise barrier application in several EU countries and in Croatia. It describes a process of introducing different noise protection solutions on Croatian market in the phase of intensive motorway construction in recent years. Namely, an extensive motorway network has been constructed in Croatia in the last 10 years. Following the process of motorway construction, noise protection walls have also been erected. Usage of different building materials and installation processes as well as variations in building expenditures has led to a comparative analysis of several types of noise protection solutions (expanded clay, wood fibre including a new eco-innovative product RUCONBAR, which incorporates rubber granules from recycled waste tyres to form a porous noise absorptive layer.

  1. Virtual parameter-estimation experiments in Bioprocess-Engineering education

    NARCIS (Netherlands)

    Sessink, O.D.T.; Beeftink, H.H.; Hartog, R.J.M.; Tramper, J.

    2006-01-01

    Cell growth kinetics and reactor concepts constitute essential knowledge for Bioprocess-Engineering students. Traditional learning of these concepts is supported by lectures, tutorials, and practicals: ICT offers opportunities for improvement. A virtual-experiment environment was developed that

  2. State of R and D of radioactive waste disposal (5). R and D of low level radioactive waste disposal. Engineered barrier: evaluation of barrier materials

    International Nuclear Information System (INIS)

    Hironaga, Michihiko

    2008-01-01

    The Central Research Institute of Electric Power Industry (CRIEPI) has researched and developed the long-term durability evaluation of engineered barrier materials for the facility of sub-surface disposal at intermediate depth. The important functions of engineered barrier are mechanical stability of construction, low hydraulic conductivity and diffusivity, and absorption of nuclide. A natural barrier plays an important part in nuclide transfer. Some examples of researches on the engineered barrier with cement and bentonite are reported. They contained the leaching test of hardened cement paste using X-ray microanalysis, relation between the dissociation rate of montmorillonite and pH from 15 to 70 deg C, and the mechanism of gas permeability of dense bentonite. The results of leaching test showed that the modified underground water leached smaller amount of ions than the ion exchanged water. The sediment was found on the surface of hardened paste. The dissociation rate of smectite under alkaline conditions showed almost the same values as neutral conditions at 15 deg C. (S.Y.)

  3. Assessment and Measurements of Degradation Processes in the Engineering Barriers of LILW Repository

    International Nuclear Information System (INIS)

    Zeleznik, N.; Sajna, A.; Petkovsek, B.

    2013-01-01

    In 2009 the Slovenian national agency for radwaste management (ARAO) adopted the national spatial plan for the low and intermediate level waste (LILW) repository to be located in Krsko municipality near NPP Krsko. The selected option for disposal was based on a silo type structure for the near surface disposal facility that will be situated close to a saturated aquifer. The soil in the region can be described as silt that extends a few hundred meters deep. The silt also contains sections of sand or clay. As the possibility exists that the natural geological barrier system will not be able to contain radionuclide migration it is a pre requisite that the proposed LILW repository must install engineered barriers. Research on different cementation materials are currently underway in order to find sustainable materials for the manufacturing of engineered barriers for the repository (silo, backfilling, concrete containers). The research also includes the assessment of possible site specific degradation processes in order to provide a methodology for the selection of appropriate locally available materials that will minimize the degradation processes. The research methodology was based on studying the characteristics (workability, compressive strength), durability (resistance to penetration of water, freeze/thaw resistance, resistance to groundwater), rheology (heat of hydration, autogenous and concrete shrinkage) and reinforcement corrosion of different concrete compositions. The characterization results were used to develop a numerical model for degradation processes to be found in the current concrete compositions. Although initial results indicated that the current concrete compositions are satisfactory, the research must be extended to the addition of binder materials to improve the characteristics of the manufactures concrete before degradation processes can be studied. (author)

  4. Software engineering experience from the LEP experiment OPAL

    International Nuclear Information System (INIS)

    Schaile, O.

    1990-01-01

    This contribution describes some of the activities within the OPAL collaboration at LEP to apply Software Engineering Techniques for program development and data documentation. It concentrates on two aspects: Structured Analysis Techniques and a data documentation system developed within OPAL. As far as evaluations are given they are the authors view and opinion

  5. Development of backfill material as an engineered barrier in the waste package system. Interim topical report

    International Nuclear Information System (INIS)

    Wheelwright, E.J.; Hodges, F.N.; Bray, L.A.; Westsik, J.H. Jr.; Lester, D.H.; Nakai, T.L.; Spaeth, M.E.; Stula, R.T.

    1981-09-01

    A backfill barrier, emplaced between the containerized waste and the host rock, can both protect the other engineered barriers and act as a primary barrier to the release of radionuclides from the waste package. Attributes that a backfill should provide in order to carry out its required function have been identified. Primary attributes are those that have a direct effect upon the release and transport of radionuclides from the waste package. Supportive attributes do not directly affect radionuclide release but are necessary to support the primary attributes. The primary attributes, in order of importance, are: minimize (retard or exclude) the migration of ground water between the host rock and the waste canister system; retard the migration of selected chemical species (corrosive species and radionuclides) in the ground water; control the Eh and pH of the ground water within the waste-package environment. The supportive attributes are: self-seal any cracks or discontinuities in the backfill or interfacing host geology; retain performance properties at all repository temperatures; retain peformance properties during and after receiving repository levels of gamma radiation; conduct heat from the canister system to the host geology; retain mechanical properties and provide resistance to applied mechanical forces; retain morphological stability and compatibility with structural barriers and with the host geology for required period of time. Screening and selection of candidate backfill materials has resulted in a preliminary list of materials for testing. Primary emphasis has been placed on sodium and calcium bentonites and zeolites used in conjunction with quartz sand or crushed host rock. Preliminary laboratory studies have concentrated on permeability, sorption, swelling pressure, and compaction properties of candidate backfill materials

  6. Educational experiments of radiochemistry in the nuclear engineering school

    International Nuclear Information System (INIS)

    Akatsu, Eiko

    1995-06-01

    Educational experiments of radiochemistry are described. They were an improvement of educational experiment of burn-up measurement as well as experiments on a solvent extraction, a cation exchange behavior of 60 Co, liquid scintillation spectrometry and half-life determination of 87 Rb, and determination of 137 Cs in sea water. Two or one of the experiments were ordinarily studied, depending the occasional situations, by the students of the general course or of the nuclear engineering course in the Nuclear Engineering School, Nuclear Education Center, JAERI from 1976 to 1994. (author)

  7. Integrated programme of research into the behaviour of the clay engineered barrier: an example from Nagra's Grimsel test site

    International Nuclear Information System (INIS)

    Biggin, C.; Alexander, R.; Kickmaier, W.; McKinley, I.G.

    2003-01-01

    Many designs for the disposal of higher activity radioactive wastes include bentonite clay as part of the engineered barrier system (EBS). Generally, the EBS is characterised by the use of large quantities of rather simple, well-understood materials, leading to increased confidence in the predicted long-term behaviour of the EBS (see, for example, Alexander and McKinley, 1999). Despite this, several open questions remain and some of these are being examined at Nagra's Grimsel Test Site (GTS) in the central Swiss Alps as part of an integrated, international study programme (GTS Phase V: see www.grimsel.com for details). Three specific projects within GTS Phase V are currently investigating the performance assessment (PA) implications of the behaviour of bentonite in the EBS. In the first, demonstration of the overall practicability of the Spanish reference disposal concept (where canisters are placed horizontally in bentonite backfilled tunnels) for high level waste (HLW) is amongst the goals of ENRESA's Full-scale Engineered Barrier EXperiment (FEBEX). In the second, RWMC are examining the potential effects of gas migration through a bentonite-sand mixture surrounding a concrete silo in the Japanese concept for intermediate level waste (ILW) in a large-scale EBS experiment (GMT, Gas Migration Test). Finally, Nagra, in the CRR (Colloid and Radionuclide Retardation) project, is investigating the effects of bentonite colloids on migration of radionuclides at the EBS / geosphere boundary, where bentonite colloids could be produced by erosion of the bentonite backfill. Although all three projects have produced significant advances in the understanding of the behaviour of the clay EBS under in situ conditions, they are based on first generation conceptual designs and so, in the planned Phase VI of the GTS, it is proposed to move on and consider more optimised EBS designs and emplacement techniques. To facilitate integration, the focus of Phase VI will be narrowed to

  8. A Phenomenographic Investigation of the Ways Engineering Students Experience Innovation

    Science.gov (United States)

    Fila, Nicholas David

    Innovation has become an important phenomenon in engineering and engineering education. By developing novel, feasible, viable, and valued solutions to complex technical and human problems, engineers support the economic competitiveness of organizations, make a difference in the lives of users and other stakeholders, drive societal and scientific progress, and obtain key personal benefits. Innovation is also a complex phenomenon. It occurs across a variety of contexts and domains, encompasses numerous phases and activities, and requires unique competency profiles. Despite this complexity, many studies in engineering education focus on specific aspects (e.g., engineering students' abilities to generate original concepts during idea generation), and we still know little about the variety of ways engineering students approach and understand innovation. This study addresses that gap by asking: 1. What are the qualitatively different ways engineering students experience innovation during their engineering projects? 2. What are the structural relationships between the ways engineering students experience innovation? This study utilized phenomenography, a qualitative research method, to explore the above research questions. Thirty-three engineering students were recruited to ensure thorough coverage along four factors suggested by the literature to support differences related to innovation: engineering project experience, academic major, year in school, and gender. Each participant completed a 1-2 hour, semi-structured interview that focused on experiences with and conceptions of innovation. Whole transcripts were analyzed using an eight-stage, iterative, and comparative approach meant to identify a limited number of categories of description (composite ways of experiencing innovation comprised of the experiences of several participants), and the structural relationships between these categories. Phenomenographic analysis revealed eight categories of description that were

  9. The Effects of Fire on the Function of the 200-BP-1 Engineered Surface Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Anderson L.; Link, Steven O.; Hasan, Nazmul; Draper, Kathryn E.

    2009-09-01

    A critical unknown in use of barrier technology for long-term waste isolation is performance after a major disturbance especially when institutional controls are intact, but there are no resources to implement corrective actions. The objective of this study was to quantify the effects of wild fire on alterations the function of an engineered barrier. A controlled burn September 26, 2008 was used to remove all the vegetation from the north side of the barrier. Flame heights exceeded 9 m and temperatures ranged from 250 oC at 1.5 cm below the surface to over 700 oC at 1 m above the surface. Post-fire analysis of soil properties show significant decreases in wettability, hydraulic conductivity, air entry pressure, organic matter, and porosity relative to pre-fire conditions whereas dry bulk density increased. Decreases in hydraulic conductivity and wettabilty immediately after the fire are implicated in a surface runoff event that occurred in January 2009, the first in 13 years. There was a significant increase in macro-nutrients, pH, and electrical conductivity. After one year, hydrophobicity has returned to pre-burn levels with only 16% of samples still showing signs of decreased wettability. Over the same period, hydraulic conductivity and air entry pressure returned to pre-burn levels at one third of the locations but remained identical to values recorded immediately after the fire at the other two thirds. Soil nutrients, pH, and electrical conductivity remain elevated after 1 year. Species composition on the burned surface changed markedly from prior years and relative to the unburned surface and two analog sites. An increase in the proportion of annuals and biennials is characteristic of burned surfaces that have become dominated by ruderal species. Greenhouse seedling emergence tests conducted to assess the seed bank of pre- and post-burn soils and of two analog sites at the McGee Ranch show no difference in the number of species emerging from soils collected

  10. Homogeneous Reactor Experiment (HRE) Pond cryogenic barrier technology demonstration: Pre-barrier subsurface hydrology and contaminant transport investigation

    International Nuclear Information System (INIS)

    Moline, G.R.

    1998-03-01

    The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes that has since been drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by a tributary that empties into Melton Branch Creek and that contains significant concentrations of radioactive contaminants, primarily 90 Sr. Because of the proximity of the tributary to the HRE disposal site and the probable flow of groundwater from the site to the tributary, it is hypothesized that the HRE Pond is a source of contamination to he creek. As a means for temporary containment of contaminants within the impoundment, a cryogenic barrier technology demonstration was initiated in FY96 with a background hydrologic investigation that continued through FY97. Cryogenic equipment installation was completed in FY97, and freezing was initiated in September of 1997. This report documents the results of a hydrologic and geologic investigation of the HRE Pond/cryogenic barrier site. The purpose of this investigation is to evaluate the hydrologic conditions within and around the impoundment in order to meet the following objectives: (1) to provide a pre-barrier subsurface hydrologic baseline for post-barrier performance assessment; (2) to confirm that the impoundment is hydraulically connected to the surrounding sediments; and (3) to determine the likely contaminant exit pathways from the impoundment. The methods of investigation included water level and temperature monitoring in a network of wells and standpipes in and surrounding the impoundment, a helium tracer test conducted under ambient flow conditions, and geologic logging during the drilling of boreholes for installation of cryogenic probes and temperature monitoring wells

  11. Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

    International Nuclear Information System (INIS)

    Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-01-01

    Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities to simulate) impacts of coupled processes on radionuclide transport in different components of EBS, as well as the interaction between near-field host rock (e.g., clay) and EBS and how they effect radionuclide release. This final report documents the progress that LBNL has made in its focus areas. Specifically, Section 2 summarizes progress on literature review for THMC processes and reactive-diffusive radionuclide transport in bentonite. The literature review provides a picture of the state-of-the-art of the relevant research areas

  12. Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

    Energy Technology Data Exchange (ETDEWEB)

    Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities to simulate) impacts of coupled processes on radionuclide transport in different components of EBS, as well as the interaction between near-field host rock (e.g., clay) and EBS and how they effect radionuclide release. This final report documents the progress that LBNL has made in its focus areas. Specifically, Section 2 summarizes progress on literature review for THMC processes and reactive-diffusive radionuclide transport in bentonite. The literature review provides a picture of the state-of-the-art of the relevant research areas

  13. Plasma diagnostic techniques in thermal-barrier tandem-mirror fusion experiments

    International Nuclear Information System (INIS)

    Silver, E.H.; Clauser, J.F.; Carter, M.R.; Failor, B.H.; Foote, J.H.; Hornady, R.S.; James, R.A.; Lasnier, C.J.; Perkins, D.E.

    1986-01-01

    We review two classes of plasma diagnostic techniques used in thermal-barrier tandem-mirror fusion experiments. The emphasis of the first class is to study mirror-trapped electrons at the thermal-barrier location. The focus of the second class is to measure the spatial and temporal behavior of the plasma space potential at various axial locations. The design and operation of the instruments in these two categories are discussed and data that are representative of their performance is presented

  14. Experiences of psychosocial and programme-related barriers to ...

    African Journals Online (AJOL)

    Kathryn van Boom

    recovery in lifestyle interventions for noncommunicable diseases. P Skowno, PhD1 ... 3Department of Psychiatry and MRC Unit on Anxiety and Stress Disorders, ... key risk factors such as unhealthy diet, physical inactivity ... work to enhance the sharing of experiences[7]. .... caused, and the other is completely self-induced.

  15. Disposal systems evaluations and tool development: Engineered Barrier System (EBS) evaluation

    International Nuclear Information System (INIS)

    Rutqvist, Jonny; Liu, Hui-Hai; Steefel, Carl I.; Serrano de Caro, M.A.; Caporuscio, Florie Andre; Birkholzer, Jens T.; Blink, James A.; Sutton, Mark A.; Xu, Hongwu; Buscheck, Thomas A.; Levy, Schon S.; Tsang, Chin-Fu; Sonnenthal, Eric; Halsey, William G.; Jove-Colon, Carlos F.; Wolery, Thomas J.

    2011-01-01

    Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems

  16. Disposal systems evaluations and tool development : Engineered Barrier System (EBS) evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny (LBNL); Liu, Hui-Hai (LBNL); Steefel, Carl I. (LBNL); Serrano de Caro, M. A. (LLNL); Caporuscio, Florie Andre (LANL); Birkholzer, Jens T. (LBNL); Blink, James A. (LLNL); Sutton, Mark A. (LLNL); Xu, Hongwu (LANL); Buscheck, Thomas A. (LLNL); Levy, Schon S. (LANL); Tsang, Chin-Fu (LBNL); Sonnenthal, Eric (LBNL); Halsey, William G. (LLNL); Jove-Colon, Carlos F.; Wolery, Thomas J. (LLNL)

    2011-01-01

    Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems

  17. Engineering teacher training models and experiences

    Science.gov (United States)

    González-Tirados, R. M.

    2009-04-01

    Institutions and Organisations that take training seriously and devote time, effort and resources, etc, to their own teams are more likely to succeed, since both initial teacher training and continuous improvement, studies, hours of group discussion, works on innovation and educational research, talks and permanent meetings, etc, will all serve to enhance teaching and its quality. Teachers will be able to introduce new components from previously taught classes into their university teaching which will contribute to improving their work and developing a suitable academic environment to include shared objectives, teachers and students. Moreover, this training will serve to enhance pedagogic innovation, new teaching-learning methodologies and contribute to getting teaching staff involved in respect of the guidelines set out by the EHEA. Bearing in mind that training and motivation can be key factors in any teacher's "performance", their productivity and the quality of their teaching, Teacher Training for a specific post inside the University Organisation is standard practice of so-called Human Resources management and an integral part of a teacher's work; it is a way of professionalising the teaching of the different branches of Engineering. At Madrid Polytechnic University, in the Institute of Educational Sciences (ICE), since it was founded in 1972, we have been working hard with university teaching staff. But it was not until 1992 after carrying out various studies on training needs that we planned and programmed different training actions, offering a wide range of possibilities. Thus, we designed and taught an "Initial Teacher Training Course", as it was first called in 1992, a programme basically aimed to train young Engineering teachers just setting out on their teaching career. In 2006, the name was changed to "Advanced University Teacher Training Course". Subsequently, with the appearance of the Bologna Declaration and the creation of the European Higher

  18. Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

    2012-01-01

    Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

  19. Hybrid rocket engine, theoretical model and experiment

    Science.gov (United States)

    Chelaru, Teodor-Viorel; Mingireanu, Florin

    2011-06-01

    The purpose of this paper is to build a theoretical model for the hybrid rocket engine/motor and to validate it using experimental results. The work approaches the main problems of the hybrid motor: the scalability, the stability/controllability of the operating parameters and the increasing of the solid fuel regression rate. At first, we focus on theoretical models for hybrid rocket motor and compare the results with already available experimental data from various research groups. A primary computation model is presented together with results from a numerical algorithm based on a computational model. We present theoretical predictions for several commercial hybrid rocket motors, having different scales and compare them with experimental measurements of those hybrid rocket motors. Next the paper focuses on tribrid rocket motor concept, which by supplementary liquid fuel injection can improve the thrust controllability. A complementary computation model is also presented to estimate regression rate increase of solid fuel doped with oxidizer. Finally, the stability of the hybrid rocket motor is investigated using Liapunov theory. Stability coefficients obtained are dependent on burning parameters while the stability and command matrixes are identified. The paper presents thoroughly the input data of the model, which ensures the reproducibility of the numerical results by independent researchers.

  20. Optical engineering: understanding optical system by experiments

    Science.gov (United States)

    Scharf, Toralf

    2017-08-01

    Students have to be educated in theoretical and practical matters. Only one of them does not allow attacking complex problems in research, development, and management. After their study, students should be able to design, construct and analyze technical problems at highest levels of complexity. Who never experienced the difficulty of setting up measurements will not be able to understand, plan and manage such complex tasks in her/his future career. At EPFL a course was developed for bachelor education and is based on three pillars: concrete actions (enactive) to be done by the students, a synthesis of their work by writing a report (considered as the iconic part) and inputs from the teacher to generalize the findings and link it to a possible complete abstract description (symbolic). Intensive tutoring allowed an intermodal transfer between these categories. This EIS method originally introduced by Jerome Bruner for small children is particular well adapted for engineer education for which theoretical understanding often is not enough. The symbiosis of ex-cathedra lecture and practical work in a classroom-like situation presents an innovative step towards integrated learning that complements perfectly more abstract course principles like online courses.

  1. Sensitivity of performance assessment of the engineered barriers to nuances of release rate criteria

    International Nuclear Information System (INIS)

    Oliver, D.L.R.

    1987-01-01

    The United States Nuclear Regulatory Commission (NRC) has established criteria for the long-term performance of proposed high-level waste repositories. As with any regulation, the criteria may be interpreted in several ways. Due to the high capital costs and the emotional political climate associated with any high-level radioactive waste repository, it is important that there be an early consensus regarding interpretations of the criteria, and what assumptions may be used to demonstrate compliance with them. This work uses analytic solutions of mass transport theory to demonstrate how sensitive performance analyses are to various nuances of the NRC release rate criterion for the engineered barriers. The analysis is directed at the proposed repository in basalt at the Hanford site in Washington State

  2. Biomimetic thermal barrier coating in jet engine to resist volcanic ash deposition

    Science.gov (United States)

    Song, Wenjia; Major, Zsuzsanna; Schulz, Uwe; Muth, Tobias; Lavallée, Yan; Hess, Kai-Uwe; Dingwell, Donald B.

    2017-04-01

    The threat of volcanic ash to aviation safety is attracting extensive attention when several commercial jet aircraft were damaged after flying through volcanic ash clouds from the May 1980 eruptions of Mount St. Helen in Washington, U.S. and especially after the air traffic disruption in 2010 Eyjafjallajökull eruption. A major hazard presented by volcanic ash to aircraft is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Due to the fact ash has a lower melting point, around 1100 °C, than the gas temperature in the hot section (between 1400 to 2000 °C), this cause the ash to melt and potentially stick to the internal components (e.g., combustor and turbine blades), this cause the ash to melt and potentially stick to the internal components of the engine creating, substantial damage or even engine failure after ingestion. Here, inspiring form the natural surface of lotus leaf (exhibiting extreme water repellency, known as 'lotus effect'), we firstly create the multifunctional surface thermal barrier coatings (TBCs) by producing a hierarchical structure with femtosecond laser pulses. In detail, we investigate the effect of one of primary femtosecond laser irradiation process parameter (scanning speed) on the hydrophobicity of water droplets onto the two kinds of TBCs fabricated by electron-beam physical vapor deposition (EB-PVD) and air plasma spray (APS), respectively as well as their corresponding to morphology. It is found that, comparison with the original surface (without femtosecond laser ablation), all of the irradiated samples demonstrate more significant hydrophobic properties due to nanostructuring. On the basis of these preliminary room-temperature results, the wettability of volcanic ash droplets will be analysed at the high temperature to constrain the potential impact of volcanic ash on the jet engines.

  3. Parallax barrier engineering for image quality improvement in an autostereoscopic 3D display.

    Science.gov (United States)

    Kim, Sung-Kyu; Yoon, Ki-Hyuk; Yoon, Seon Kyu; Ju, Heongkyu

    2015-05-18

    We present a image quality improvement in a parallax barrier (PB)-based multiview autostereoscopic 3D display system under a real-time tracking of positions of a viewer's eyes. The system presented exploits a parallax barrier engineered to offer significantly improved quality of three-dimensional images for a moving viewer without an eyewear under the dynamic eye tracking. The improved image quality includes enhanced uniformity of image brightness, reduced point crosstalk, and no pseudoscopic effects. We control the relative ratio between two parameters i.e., a pixel size and the aperture of a parallax barrier slit to improve uniformity of image brightness at a viewing zone. The eye tracking that monitors positions of a viewer's eyes enables pixel data control software to turn on only pixels for view images near the viewer's eyes (the other pixels turned off), thus reducing point crosstalk. The eye tracking combined software provides right images for the respective eyes, therefore producing no pseudoscopic effects at its zone boundaries. The viewing zone can be spanned over area larger than the central viewing zone offered by a conventional PB-based multiview autostereoscopic 3D display (no eye tracking). Our 3D display system also provides multiviews for motion parallax under eye tracking. More importantly, we demonstrate substantial reduction of point crosstalk of images at the viewing zone, its level being comparable to that of a commercialized eyewear-assisted 3D display system. The multiview autostereoscopic 3D display presented can greatly resolve the point crosstalk problem, which is one of the critical factors that make it difficult for previous technologies for a multiview autostereoscopic 3D display to replace an eyewear-assisted counterpart.

  4. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    Science.gov (United States)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  5. Summary of results of underground engineering experience

    Energy Technology Data Exchange (ETDEWEB)

    Holzer, F [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1969-07-01

    Results pertinent to the use of nuclear explosives in underground engineering applications have been accumulating for the past 10 years from the Plowshare and Weapons tests of the AEC. Thus, predictive and measurement techniques of shock effects and chimney formation were developed in the course of analyzing explosions in granite, salt, and dolomite. The ability to predict effects related specifically to safety has resulted from many measurements on detonations at the Nevada Test Site, where also many of the techniques for handling, emplacing, and firing the explosive have been developed. This gestation period culminated in the execution of Project Gasbuggy, jointly sponsored by industry and government, and the first nuclear explosion in a gasbearing formation. The Gasbuggy explosive had a nominal yield of 25 kt and was detonated 4240 ft below the surface in the San Juan Basin in northwestern New Mexico on December 10, 1967. The shot point was 40 ft below the lower boundary of a 285-ft-thick gas-bearing sandstone formation of very low permeability. No radioactive venting occurred, and no damage to surrounding gas wells or structures resulted. Post-shot geophysical exploration and gas production tests have revealed that the nuclear explosion created a subsurface chimney approximately 160 ft in diameter and 335 ft high. Fractures appear to extend to about 400 ft symmetrically from the detonation point, with shifts or offsets along geological weaknesses extending out to perhaps 750 ft. Presently, radioactive constituents in the gas consist of tritium and krypton-85, with concentrations of approximately 10 {mu}Ci/ft{sup 3} and 1.5 {mu}Ci/ft{sup 3} respectively. These concentrations are decreasing a gas withdrawn from the chimney is replaced by formation gas. Tests to evaluate the increase in productivity and ultimate recovery are currently in progress. (author)

  6. Summary of results of underground engineering experience

    International Nuclear Information System (INIS)

    Holzer, F.

    1969-01-01

    Results pertinent to the use of nuclear explosives in underground engineering applications have been accumulating for the past 10 years from the Plowshare and Weapons tests of the AEC. Thus, predictive and measurement techniques of shock effects and chimney formation were developed in the course of analyzing explosions in granite, salt, and dolomite. The ability to predict effects related specifically to safety has resulted from many measurements on detonations at the Nevada Test Site, where also many of the techniques for handling, emplacing, and firing the explosive have been developed. This gestation period culminated in the execution of Project Gasbuggy, jointly sponsored by industry and government, and the first nuclear explosion in a gasbearing formation. The Gasbuggy explosive had a nominal yield of 25 kt and was detonated 4240 ft below the surface in the San Juan Basin in northwestern New Mexico on December 10, 1967. The shot point was 40 ft below the lower boundary of a 285-ft-thick gas-bearing sandstone formation of very low permeability. No radioactive venting occurred, and no damage to surrounding gas wells or structures resulted. Post-shot geophysical exploration and gas production tests have revealed that the nuclear explosion created a subsurface chimney approximately 160 ft in diameter and 335 ft high. Fractures appear to extend to about 400 ft symmetrically from the detonation point, with shifts or offsets along geological weaknesses extending out to perhaps 750 ft. Presently, radioactive constituents in the gas consist of tritium and krypton-85, with concentrations of approximately 10 μCi/ft 3 and 1.5 μCi/ft 3 respectively. These concentrations are decreasing a gas withdrawn from the chimney is replaced by formation gas. Tests to evaluate the increase in productivity and ultimate recovery are currently in progress. (author)

  7. NASA GSFC Science Communication Working Group: Addressing Barriers to Scientist and Engineer Participation in Education and Public Outreach Activities

    Science.gov (United States)

    Bleacher, L.; Hsu, B. C.; Campbell, B. A.; Hess, M.

    2011-12-01

    The Science Communication Working Group (SCWG) at NASA Goddard Space Flight Center (GSFC) has been in existence since late 2007. The SCWG is comprised of education and public outreach (E/PO) professionals, public affairs specialists, scientists, and engineers. The goals of the SCWG are to identify barriers to scientist and engineer engagement in E/PO activities and to enable those scientists and engineers who wish to contribute to E/PO to be able to do so. SCWG members have held meetings with scientists and engineers across GSFC to determine barriers to their involvement in E/PO. During these meetings, SCWG members presented examples of successful, ongoing E/PO projects, encouraged active research scientists and engineers to talk about their own E/PO efforts and what worked for them, discussed the E/PO working environment, discussed opportunities for getting involved in E/PO (particularly in high-impact efforts that do not take much time), handed out booklets on effective E/PO, and asked scientists and engineers what they need to engage in E/PO. The identified barriers were consistent among scientists in GSFC's four science divisions (Earth science, planetary science, heliophysics, and astrophysics). Common barriers included 1) lack of time, 2) lack of funding support, 3) lack of value placed on doing E/PO by supervisors, 4) lack of training on doing appropriate/effective E/PO for different audiences, 5) lack of awareness and information about opportunities, 6) lack of understanding of what E/PO really is, and 7) level of effort required to do E/PO. Engineers reported similar issues, but the issues of time and funding support were more pronounced due to their highly structured work day and environment. Since the barriers were identified, the SCWG has taken a number of steps to address and rectify them. Steps have included holding various events to introduce scientists and engineers to E/PO staff and opportunities including an E/PO Open House, brown bag seminars on

  8. Research on the NPP human factors engineering operating experience review

    International Nuclear Information System (INIS)

    Ren Xiangchen; Miao Hongxing; Ning Zhonghe

    2006-01-01

    This paper addresses the importance of the human factors engineering (HFE) for the design of nuclear power plant (NPP), especially for the design of human-machine interface in the NPP. It also summarizes the scope and content of the NPP HFE. The function, scope, content and process of the NPP human factors engineering operating experience review (OER) are mainly focused on, and significantly discussed. Finally, it briefly introduces the situation of the studies on the OER in China. (authors)

  9. The ward round--patient experiences and barriers to participation.

    Science.gov (United States)

    Swenne, Christine Leo; Skytt, Bernice

    2014-06-01

    Patients' participation is essential to their well-being and sense of coherence, as well as to their understanding of and adherence to prescribed treatments. Ward rounds serve as a forum for sharing information between patient and caregiver. The purpose of the ward round is to obtain information and plan medical and nursing care through staff-patient communication. The aim and objective of this study was to investigate patients' experiences during the ward round and their ability to participate in their care. The study was qualitative and descriptive in design. Fourteen inpatients at a cardiovascular ward were interviewed. Qualitative content analysis was used for the analysis. The ethics of scientific work were adhered to. Each study participant gave his/her informed consent based on verbal and written information. The study was approved by the Research Ethics Committee at Uppsala University. The analysis revealed one theme and three subthemes related to patients' experiences of ward rounds. The main theme was handling of information from the daily ward round while waiting for private consultation. The subthemes were making the best of the short time spent on ward rounds; encountering traditional roles and taking comfort in staff competency; and being able to choose the degree to which one participates in the decision-making process. Several aspects of traditional ward round routines could be improved in regard to the two-way information exchange process between caregivers and patient. Patients' and caregivers' ability to communicate their goals and the environment in which the communication occurs are of great importance. The information provided by nurses is easier to understand than that provided by physicians. The atmosphere must be open; the patient should be treated with empathy by staff; and patients' right to participate must be acknowledged by all healthcare professionals involved. © 2013 Nordic College of Caring Science.

  10. Educational laboratory experiments on chemistry in a nuclear engineering school

    International Nuclear Information System (INIS)

    Akatsu, E.

    1982-01-01

    An educational laboratory experiment on radiochemistry was investigated by students in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. Most of them are not chemical engineers, but electrical and mechanical engineers. Therefore, the educational experiment was designed for them by introducing a ''word experiment'' in the initial stage and by reducing the chemical procedure as far as possible. It began with calculations on a simple solvent extraction process-the ''word experiment''--followed by the chemical separation of 144 Pr from 144 Ce with tri-n-butyl phosphate in a nitric acid system and then measurement of the radioactive decay and growth of the separated 144 Pr and 144 Ce, respectively. The chemical procedure was explained by the phenomenon but not by the mechanism of chelation. Most students thought the experiment was an exercise in solvent extraction or radiochemical separation rather than a radioactive equilibrium experiment. However, a pure chemist considered it as a sort of physical experiment, where the chemical procedure was used only for preparation of measuring samples. Another experiment, where 137 Cs was measured after isolation with ammonium phosphomolybdate, was also investigated. The experiment eliminated the need for students who were not chemists to know how to use radioactive tracers. These students appreciated the realization that they could understand the radioactivity in the environmental samples in a chemical frame of reference even though they were not chemists

  11. Examining E-Learning Barriers As Perceived By Faculty 
Members Of Engineering Colleges In The Jordanian Universities

    OpenAIRE

    Muhammad K. AL-ALAWNEH,

    2014-01-01

    Employing computer's technology that includes e-learning system in the field of Engineering is a vital issue which needs to be discussed. Therefore, this study purposed to examine e-learning barriers as perceived by faculty members of engineering in three major universities in Jordan (Yarmouk University, Jordan University of Science and Technology, and Al-Balqaa Applied University) in the second semester of 2012. The study's instrument was distributed to collect the data from a sam...

  12. Technology assessment guide for application of engineered sorbent barriers to low-level radioactive waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Jones, E.O.; Depner, J.P.

    1989-06-01

    An engineered sorbent barrier (ESB) uses sorbent materials (such as activated carbon or natural zeolites) to restrict migration of radionuclides from low-level waste sites. The permeability of the ESB allows moisture to pass while the sorbent material traps or absorbs contaminants. In contrast, waste sites with impermeable barriers could fill with water, especially those waste sites in humid climates. A sorbent barrier can be a simple, effective, and inexpensive method for restricting radionuclide migration. This report provides information and references to be used in assessing the sorbent barrier technology for low-level waste disposal. The ESB assessment is based on sorbent material and soil properties, site conditions, and waste properties and inventories. These data are used to estimate the thickness of the barrier needed to meet all performance requirements for the waste site. This document addresses the following areas: (1) site information required to assess the need and overall performance of a sorbent barrier; (2) selection and testing of sorbent materials and underlying soils; (3) use of radionuclide transport models to estimate the required barrier thickness and long-term performance under a variety of site conditions; (4) general considerations for construction and quality assurance; and (5) cost estimates for applying the barrier. 37 refs., 6 figs., 2 tabs.

  13. Experience in education and training of gas engineers in Russia

    International Nuclear Information System (INIS)

    Basniev, K.; Vladimirov, A.

    1997-01-01

    Experience gained in training and retraining of engineers for gas industry is considered in the report. The report contains the material on modern state of higher technical education in Russia in view of the reforms taking place in this country. The report deals with questions concerning the experience gained in a specialized training of gas engineers at higher educational establishments of Russia including training of specialists for foreign countries. Conditions under which retraining of engineers involved in gas industry takes place are presented in the report. The report is based mainly on the experience gained by the Russian leading higher educational establishment of oil and gas profile, that is the State Gubkin Oil and Gas Academy. (au)

  14. Plasma engineering assessments of compact ignition experiments

    International Nuclear Information System (INIS)

    Houlberg, W.A.

    1985-01-01

    Confinement, startup sequences, and fast-alpha particle effects are assessed for a class of compact tokamak ignition experiments having high toroidal magnetic fields (8 to 12 T) and high toroidal currents (7 to 10 MA). The uncertainties in confinement scaling are spanned through examples of performance with an optimistic model based on ohmically heated plasmas and a pessimistic model that includes confinement degradation by both auxiliary and alpha heating. The roles of neoclassical resistivity enhancement and sawtooth behavior are also evaluated. Copper toroidal field coils place restrictions on pulse lengths due to resistive heating, so a simultaneous rampup of the toroidal field and plasma current is proposed as a means of compressing the startup phase and lengthening the burn phase. If the ignition window is small, fast-alpha particle physics is restricted to the high-density regime where a short slowing-down time leads to low fast-particle density and pressure contributions. Under more optimistic confinement, a larger ignition margin broadens the range of alpha particle physics that can be addressed. These issues are illustrated through examples of transport simulations for a set of machine parameters called BRAND-X, which typify the designs under study

  15. Plasma engineering assessments of compact ignition experiments

    International Nuclear Information System (INIS)

    Houlberg, W.A.

    1986-01-01

    Confinement, startup sequences, and fast-alpha particle effects are assessed for a class of compact tokamak ignition experiments having high toroidal magnetic fields (8-12 T) and high toroidal currents (7-10 MA). The uncertainties in confinement scaling are spanned through examples of performance with an optimistic model based on ohmically heated plasmas and a pessimistic model that includes confinement degradation by both auxiliary and alpha heating. The roles of neoclassical resistivity enhancement and sawtooth behavior are also evaluated. Copper toroidal field coils place restrictions on pulse lengths due to resistive heating, so a simultaneous rampup of the toroidal field and plasma current is proposed as a means of compressing the startup phase and lengthening the burn phase. If the ignition window is small, fast-alpha particle physics is restricted to the high-density regime where a short slowing-down time leads to low fast-particle density and pressure contributions. Under more optimistic confinement, a larger ignition margin broadens the range of alpha particle physics that can be addressed. These issues are illustrated through examples of transport simulations for a set of machine parameters called BRAND-X, which typify the designs under study

  16. Barriers to Conducting Supervised Agricultural Experiences as Perceived by Preservice Agricultural Education Teachers

    Directory of Open Access Journals (Sweden)

    J. Joey Blackburn

    2014-10-01

    Full Text Available The purpose of this descriptive study was to assess preservice agriculture teachers’ perceptions of the importance of Supervised Agricultural Experience (SAE and their views on barriers to conducting SAE. A census of the sophomore-level agricultural education course at Oklahoma State University was conducted to measure perceptions at the beginning and end of the course. This study was framed upon Ajzen’s Theory of Planned Behavior. Results indicated that preservice teachers perceived SAE was an important component of agricultural education and important at the secondary school they attended. The greatest barrier to conducting SAE was their lack of familiarity with newer SAE categories. This was true at both the beginning and end of the course. It is recommended that preservice teachers receive instruction on and experiences in all types of SAE. This would increase the likelihood of preservice teachers perceiving they have control over this barrier regarding SAE implementation. This cohort of preservice teachers should be surveyed over time to determine change in their perceptions of barriers to SAE implementation as they progress in the agricultural education program and through their careers. Further, the views of in-service teachers should also be assessed to determine if perceived barriers differ with professional experience.

  17. Beyond Bias and Barriers: Fulfilling the Potential of Women in Academic Science and Engineering

    Science.gov (United States)

    Agogino, Alice

    2007-04-01

    Review of the report by the National Academies, with a focus on action strategies in the physical sciences. Women face barriers to hiring and promotion in research universities in many fields of science and engineering; a situation that deprives the United States of an important source of talent as the country faces increasingly stiff global competition in higher education, science and technology, and the marketplace. Eliminating gender bias in universities requires immediate, overarching reform and decisive action by university administrators, professional societies, government agencies, and Congress. Forty years ago, women made up only 3 percent of America's scientific and technical workers, but by 2003 they accounted for nearly one-fifth. In addition, women have earned more than half of the bachelor's degrees awarded in science and engineering since 2000. However, their representation on university and college faculties fails to reflect these gains. Among science and engineering Ph.D.s, four times more men than women hold full-time faculty positions. And minority women with doctorates are less likely than white women or men of any racial or ethnic group to be in tenure positions. The report urges higher education organizations and professional societies to form collaborative, self-monitoring body that would recommend standards for faculty recruitment, retention, and promotion; collect data; and track compliance across institutions. A ``report card'' template is provided in the report. To read the report online, add a comment, or purchase hard copy, go to: http://www.engineeringpathway.com/ep/learningresource/summary/index.jhtml?id=94A4929D-F1B2-432E-8167-63335569CB4E.

  18. Managing reality shock: Expectations versus experiences of graduate engineers

    Directory of Open Access Journals (Sweden)

    Sarah Riordan

    2007-10-01

    Full Text Available The objective of the study is an analysis of the relationship between the work expectations and experiences of graduate engineers during their early career period. It reports on discrepancies in graduates’ expectations of the world of work and the reality of the early career stage. Conclusions include recommendations of how "reality shock" can be managed better by both organisations and individuals. Qualitative data were obtained through in-depth interviews with sixteen participants with less than five years work experience, employed in a large utility organisation in the Western Cape. Results indicate that participants experience significant incongruence between their expectations of work and work experiences.

  19. Academics' Perceptions of the Challenges and Barriers to Implementing Research-Based Experiences for Undergraduates

    Science.gov (United States)

    Brew, Angela; Mantai, Lilia

    2017-01-01

    How can universities ensure that strategic aims to integrate research and teaching through engaging students in research-based experiences be effectively realised within institutions? This paper reports on the findings of a qualitative study exploring academics' perceptions of the challenges and barriers to implementing undergraduate research.…

  20. African American Women Aspiring to the Superintendency: Lived Experiences and Barriers

    Science.gov (United States)

    Angel, Roma B.; Killacky, Jim; Johnson, Patricia R.

    2013-01-01

    Focused on the absence of a viable population of African American women in the superintendency, this study addressed barriers described by 10 credentialed, district-level Southern women who hold advanced education degrees coupled with years of leadership experience. This phenomenological study used interview methodology to uncover the lived…

  1. Technology CAD of silicided Schottky barrier MOSFET for elevated source-drain engineering

    International Nuclear Information System (INIS)

    Saha, A.R.; Chattopadhyay, S.; Bose, C.; Maiti, C.K.

    2005-01-01

    Technology CAD has been used to study the performance of a silicided Schottky barrier (SB) MOSFET with gate, source and drain contacts realized with nickel-silicide. Elevated source-drain structures have been used towards the S/D engineering of CMOS devices. A full process-to-device simulation has been employed to predict the performance of sub-micron SB n-MOSFETs for the first time. A model for the diffusion and alloy growth kinetics has been incorporated in SILVACO-ATLAS and ATHENA to explore the processing and design parameter space for the Ni-silicided MOSFETs. The temperature and concentration dependent diffusion model for NiSi have been developed and necessary material parameters for nickel-silicide and epitaxial-Si have been incorporated through the C-interpreter function. Two-dimensional (2D) process-to-device simulations have also been used to study the dc and ac (RF) performance of silicided Schottky barrier (SB) n-MOSFETs. The extracted sheet resistivity, as a function of annealing temperature of the silicided S/D contacts, is found to be lower than the conventional contacts currently in use. It is also shown that the Technology CAD has the full capability to predict the possible dc and ac performance enhancement of a MOSFET with elevated S/D structures. While the simulated dc performance shows a clear enhancement, the RF analyses show no performance degradation in the cut-off frequency/propagation delay and also improve the ac performance due to the incorporation of silicide contacts in the S/D region

  2. Technology CAD of silicided Schottky barrier MOSFET for elevated source-drain engineering

    Energy Technology Data Exchange (ETDEWEB)

    Saha, A.R. [Department of Electronics and ECE, IIT, Kharagpur 721302 (India)]. E-mail: ars.iitkgp@gmail.com; Chattopadhyay, S. [Department of Electronics and ECE, IIT, Kharagpur 721302 (India); School of Electrical, Electronics and Computer Engineering, University of Newcastle, Newcastle upon Tyne (United Kingdom); Bose, C. [Department of Electronics and Telecommunication Engineering, Jadavpur University, Calcutta 700032 (India); Maiti, C.K. [Department of Electronics and ECE, IIT, Kharagpur 721302 (India)

    2005-12-05

    Technology CAD has been used to study the performance of a silicided Schottky barrier (SB) MOSFET with gate, source and drain contacts realized with nickel-silicide. Elevated source-drain structures have been used towards the S/D engineering of CMOS devices. A full process-to-device simulation has been employed to predict the performance of sub-micron SB n-MOSFETs for the first time. A model for the diffusion and alloy growth kinetics has been incorporated in SILVACO-ATLAS and ATHENA to explore the processing and design parameter space for the Ni-silicided MOSFETs. The temperature and concentration dependent diffusion model for NiSi have been developed and necessary material parameters for nickel-silicide and epitaxial-Si have been incorporated through the C-interpreter function. Two-dimensional (2D) process-to-device simulations have also been used to study the dc and ac (RF) performance of silicided Schottky barrier (SB) n-MOSFETs. The extracted sheet resistivity, as a function of annealing temperature of the silicided S/D contacts, is found to be lower than the conventional contacts currently in use. It is also shown that the Technology CAD has the full capability to predict the possible dc and ac performance enhancement of a MOSFET with elevated S/D structures. While the simulated dc performance shows a clear enhancement, the RF analyses show no performance degradation in the cut-off frequency/propagation delay and also improve the ac performance due to the incorporation of silicide contacts in the S/D region.

  3. Project-Based Laboratory Experiences in Mechanical Engineering

    Directory of Open Access Journals (Sweden)

    Narendra Sharma

    2011-12-01

    Full Text Available In this paper we describe project-based laboratories in Mechanical Engineering designed to provide semester-long team experiences which mimic the real life industrial processes of design, development, testing and optimization. The labs are focused on courses at the sophomore level and thus require special attention to constraints of student backgrounds and experience. This paper describes laboratory projects in Dynamics and Fluid Mechanics.

  4. The field migration tests of 237Np, 238Pu, 241Am and 90Sr in aerated loess, aquifer and engineering barrier materials

    International Nuclear Information System (INIS)

    Li Shushen; Wang Zhiming; Zhao Yingjie; Fan Zhiwen; Liu Chunli; An Yongfeng; Yang Yue'e; Wu Qinghua

    2003-01-01

    This paper introduces the field migration tests of 237 Np, 238 Pu, 241 Am and 90 Sr in aerated loess, aquifer and engineering barrier materials. The tests in the aerated loess and engineering barrier materials were carried out under both natural and artificial sprinkling (15 mm/d) conditions. The tests in aquifer were carried out in both assemblies packed with undisturbed aquifer media and a definite undisturbed area. The results indicate that after 3 years tests no significant migrations were seen for all nuclides in engineering barrier materials under two kinds of conditions and in aerated loess under natural conditions. For the aerated loess under artificial sprinkling conditions, 2.7 cm (center of mass) migration in the area directly below the sand tracer layer (named as area 1) and 13 cm (peak) migration in the area outside the area 1 for 90 Sr were observed; There was no migration for 237 Np, 238 Pu and 241 Am. It was discovered that the sand layer used as carrier of nuclide tracer has barrier effect on unsaturated water and an influence on nuclide migration. This has been demonstrated by the inter comparison experiment with both sand and loess as tracer carrier. In the tracer tests of undisturbed aquifer area there was no significant migration of 237 Np, 238 Pu, 241 Am and 90 Sr after 1023 days. In the assembly 8 there was no significant migration for 238 Pu and 241 Am and a small backward migration 0.95 cm for 237 Np and 4.7 cm migration (center of mass) for 90 Sr were observed. The tests also indicate that there is no significant difference of nuclide migration in ordinary and degraded cement

  5. Women's Experiences in the Engineering Laboratory in Japan

    Science.gov (United States)

    Hosaka, Masako

    2014-01-01

    This qualitative study aims to examine Japanese women undergraduate engineering students' experiences of interacting with departmental peers of the same year in the laboratory setting by using interview data of 32 final-year students at two modestly selective national universities in Japan. Expectation state theory that explains unequal…

  6. Learning English: Experiences and Needs of Saudi Engineering Students

    Science.gov (United States)

    Unruh, Susan; Obeidat, Fayiz

    2015-01-01

    In this qualitative study, Saudi engineering students talk openly of their experiences learning English in the Kingdom of Saudi Arabia (KSA) and as university students in the United States (US). These students reported that they learned only the basics of vocabulary and grammar in KSA. Consequently, they came to the US with few English skills. In…

  7. Creating meaningful learning experiences: Understanding students' perspectives of engineering design

    Science.gov (United States)

    Aleong, Richard James Chung Mun

    , relevance, and transfer. With this framework of student learning, engineering educators can enhance learning experiences by engaging all three levels of students' understanding. The curriculum studies orientation applied the three holistic elements of curriculum---subject matter, society, and the individual---to conceptualize design considerations for engineering curriculum and teaching practice. This research supports the characterization of students' learning experiences to help educators and students optimize their teaching and learning of design education.

  8. Hanford Site protective isolation surface barrier: Taking research and development to engineered application

    International Nuclear Information System (INIS)

    Myers, D.R.; Wing, N.R.

    1994-01-01

    The development of the Protective Isolation Surface Barrier has been an ongoing program since 1985. This development effort has focused on several technical areas. These technical areas include water infiltration, biointrusion, human intrusion, erosion/deposition, physical stability, barrier materials, computer modeling, long-term climate effects, natural analogs, and barrier design. This paper briefly reviews the results of the research and development in the technical areas and then explains how the results of this work have influenced the design features of the prototype barrier. A good example of this is to explain how the type and depth of the soil layer used in the barrier is related to water infiltration, biointrusion, modeling, climate, analogs, and barrier materials. Another good example is to explain the relationship of the barrier sideslopes (basalt riprap and native soil) with human intrusion, biointrusion, barrier materials, and barrier design. In general, the design features of the prototype barrier will be explained in terms of the results of the testing and development program. After the basis for prototype barrier design has been established, the paper will close by reviewing the construction of the prototype barrier, sharing the lessons learned during construction, and explaining the ongoing testing and monitoring program which will determine the success or failure of this barrier concept and the need for additional design modifications

  9. A practitioner’s experiences operationalizing Resilience Engineering

    International Nuclear Information System (INIS)

    Lay, E.; Branlat, M.; Woods, Z.

    2015-01-01

    Resilience Engineering (RE) is a reframed perspective. This begs the question, “How to operationalize a shift in perspective?” We share strategies, tactics, experiences, and observations from implementing Resilience Engineering in power generation equipment maintenance. Use of Resilience Engineering principles shifts focus to the future, to systems, and to how people really work (not the idealized version of work). We more effectively shape outcomes as we pay attention to what’s coming, looking for signs we’re outside normal work or running out of margins that enable us to adapt and respond. Use of these principles opens new possibilities grounded in theoretical fields of biology, cognitive and system sciences (understand Cartesian views of the world work well for machines but not for people) and underlain by core principles (e.g., people fundamentally want to do a good job, actions taken make sense at the time, and system factors are tremendously influential on outcomes). This paper presents a practitioner’s account of a Resilience Engineering approach in the context of power plant maintenance. The paper will describe how the introduction of RE principles was made possible through supporting/fostering shifts in perspective and gaining buy-in at various levels of the organization. - Highlights: • Resilience Engineering is a shifted perspective as compared to a new program. • RE is grounded in fields of biology, cognitive and system sciences. • We share strategies, tactics, experiences, and observations for implementing RE. • We used a middle out approach

  10. Experimental methodology to study radionuclide sorption and migration in geological formations and engineered barriers of waste repositories

    International Nuclear Information System (INIS)

    Rojo Sanz, H.

    2010-01-01

    In Spain, the waste management options include either the possibility of a final storage in a deep geological repository (DGR) or the centralized temporal surface disposal (CTS). DGRs are based in a multi-barrier concept with the geological barrier and including the vitrified waste, the metal containers and engineered barriers such as compacted bentonite and cement-based materials. On the other hand, CTS mainly considers concrete and cement to confine the metal canisters containing the waste. Radionuclide migration will mainly take place by the existence of chemical concentration gradients being thus diffusion the main transport mechanism or by the existence of hydraulic gradients due to the existence of water-conductive fractures. Radionuclide sorption/retention on the materials composing the natural and engineered barriers is the fundamental process controlling contaminant migration. The evaluation of sorption parameters and the understanding of the different mechanisms leading to radionuclide retention are very important issues. The study of diffusion processes is very relevant as well. This paper describes the main experimental methodologies applied to analyse radionuclide transport in the different barriers of radioactive repositories. Particularly we focused on obtaining of retention parameters as distribution coefficients, kd, or retardation factors, Rf, and diffusion coefficients of radionuclides. (Author) 6 refs.

  11. First experiments results about the engineering model of Rapsodie

    International Nuclear Information System (INIS)

    Chalot, A.; Ginier, R.; Sauvage, M.

    1964-01-01

    This report deals with the first series of experiments carried out on the engineering model of Rapsodie and on an associated sodium facility set in a laboratory hall of Cadarache. It conveys more precisely: 1/ - The difficulties encountered during the erection and assembly of the engineering model and a compilation of the results of the first series of experiments and tests carried out on this installation (loading of the subassemblies preheating, thermal chocks...). 2/ - The experiments and tests carried out on the two prototypes control rod drive mechanisms which brought to the choice for the design of the definitive drive mechanism. As a whole, the results proved the validity of the general design principles adopted for Rapsodie. (authors) [fr

  12. Efficacy of backfilling and other engineered barriers in a radioactive waste repository in salt

    International Nuclear Information System (INIS)

    Claiborne, H.C.

    1982-09-01

    In the United States, investigation of potential host geologic formations was expanded in 1975 to include hard rocks. Potential groundwater intrusion is leading to very conservative and expensive waste package designs. Recent studies have concluded that incentives for engineered barriers and 1000-year canisters probably do not exist for reasonable breach scenarios. The assumption that multibarriers will significantly increase the safety margin is also questioned. Use of a bentonite backfill for surrounding a canister of exotic materials was developed in Sweden and is being considered in the US. The expectation that bentonite will remain essentially unchanged for hundreds of years for US repository designs may be unrealistic. In addition, thick bentonite backfills will increase the canister surface temperature and add much more water around the canister. The use of desiccant materials, such as CaO or MgO, for backfilling seems to be a better method of protecting the canister. An argument can also be made for not using backfill material in salt repositories since the 30-cm-thick space will provide for hole closure for many years and will promote heat transfer via natural convection. It is concluded that expensive safety systems are being considered for repository designs that do not necessarily increase the safety margin. It is recommended that the safety systems for waste repositories in different geologic media be addressed individually and that cost-benefit analyses be performed

  13. Technical basis and programmatic requirements for Engineered Barrier System Field Tests

    International Nuclear Information System (INIS)

    Lin, Wunan.

    1992-11-01

    The purpose of this study plant is to describe tests known as Engineered Barrier System Field Tests (EBSFT), which are to be conducted in the Exploratory Study Facility (ESF) at Yucca Mountain, Nevada. The EBSFT is designed to provide information on the interaction between waste packages (simulated by heated containers), the surrounding rock mass, and its vadose water. The Yucca Mountain site is being characterized to determine its suitability as a potential deep geological repository for high-level nuclear waste. Water is the main medium by which radioactive nuclides travel to the accessible environment. Therefore, the movement of water over the approximate 10,000--year lifetime required for radioactive nuclide decay must be understood. Development of a repository and emplacement of nuclear wastes impose stress loadings on the repository rock mass. The stress loadings include (1) thermal energy and irradiation from the waste packages, and (2) mechanical stress due to the mining of openings, and the transporting of waste canisters. The influence f the thermal stress may extend to all lithological units, including the saturated zone under the ground water table, in Yucca Mountain. In general, the purpose of this study is to investigate the movement of water in the rock mass under the influence of the thermal loading of the waste packages. Specifically, the study will investigate heat flow mechanism, relationship between boiling and dry-out, and the rewetting of the dry-out region when the repository is cooled down

  14. Deformation stresses and mechanical behaviour of engineered barriers in the repository environment

    International Nuclear Information System (INIS)

    Ipatti, A.; Majamaeki, O.

    1991-12-01

    The report surveys functioning of the engineered barriers in the Loviisa repository under deformation stresses of the solidification product and the concrete filling material. The survey is based on the latest estimates of the waste amounts and the corresponding repository plans, and on solidification product compositions and properties. The IVOFEM and NASTRAN software was used in the structural analyses. The materials were supposed to be homogeneous and linearly elastic and dislocations small. Accordingly, the design loads were chosen conservatively so that the impacts of deformation stresses are sufficiently overestimated. A reinforced concrete container lined with cellular plastic remains a watertight structure, meeting the requirements set in view of expansion of a solidification product. In view of the stresses, the decisive time is the intermediate storage stage. The greatest stresses are found in junctions between the container wall and the bottom and cover. The concrete filling between the waste packages cannot resist the drying shrinkage and wetting expansion stresses without cracking. Concrete walls of the repository can withstand the stress caused by wetting expansion of the waste packages only when strongly reinforced. However, the forces against the walls are so big that if cracks in the concrete walls are desired to be restricted, due to reinforcement steel corrosion or wall tightness, the present type of filling material between the waste packages is not necessarily technically the best alternative

  15. Barriers to implementing the World Health Organization's Trauma Care Checklist: A Canadian single-center experience.

    Science.gov (United States)

    Nolan, Brodie; Zakirova, Rimma; Bridge, Jennifer; Nathens, Avery B

    2014-11-01

    Management of trauma patients is difficult because of their complexity and acuity. In an effort to improve patient care and reduce morbidity and mortality, the World Health Organization developed a trauma care checklist. Local stakeholder input led to a modified 16-item version that was subsequently piloted. Our study highlights the barriers and challenges associated with implementing this checklist at our hospital. The checklist was piloted over a 6-month period at St. Michael's Hospital, a Level 1 trauma center in Toronto, Canada. At the end of the pilot phase, individual, semistructured interviews were held with trauma team leaders and nursing staff regarding their experiences with the checklist. Axial coding was used to create a typology of attitudes and barriers toward the checklist, and then, vertical coding was used to further explore each identified barrier. Checklist compliance was assessed for the first 7 months. Checklist compliance throughout the pilot phase was 78%. Eight key barriers to implementing the checklist were identified as follows: perceived lack of time for the use of the checklist in critically ill patients, unclear roles, no memory trigger, no one to enforce completion, not understanding its importance or purpose, difficulty finding physicians at the end of resuscitation, staff/trainee changes, and professional hierarchy. The World Health Organization Trauma Care Checklist was a well-received tool; however, consideration of barriers to the implementation and staff adoption must be done for successful integration, with special attention to its use in critically ill patients. Therapeutic/care management, level V.

  16. Experiments in Creative Engineering at the Department of Mechanical Engineering in Kurume National College of Technology

    Science.gov (United States)

    Tanaka, Hiroshi; Hashimura, Shinji; Hiroo, Yasuaki

    We present a program to learn ability to solve problems on engineering. This program is called “Experiments in creative engineering” in the department of mechanical engineering in Kurume National College of Technology advanced engineering school. In the program, students have to determine own theme and manufacture experimental devices or some machines by themselves. The students must also perform experiments to valid the function and performance of their devices by themselves. The restriction of the theme is to manufacture a device which function dose not basically exist in the world with limited cost (up to 20,000Yen) . As the results of questionnaire of students, the program would be very effective to the creative education for the students.

  17. Business oriented educational experiments enhance active learning by engineering students

    DEFF Research Database (Denmark)

    Christiansen, Nynne Mia; Schjær-Jacobsen, Hans; Simon, Jens

    2012-01-01

    It is generally agreed that one of the keys to recreating industrial growth after the financial crisis is to mobilize universities and engineering schools to be more actively involved in innovation and entrepreneurship activities in cooperation with industrial companies. This active learning...... exploration symposium on bridging the gap between engineering education and business is proposed on the basis of the Copenhagen University College of Engineering (IHK) being involved in a DKK 50m ongoing project “Business Oriented Educational Experiments” financed by the Capital Region of Denmark...... and the European Social Fund. The project is carried out with other major educational institutions in the Copenhagen area and organized in five themes: 1) world class competences, 2) new interactions between education and business, 3) the experimenting organization, 4) education on demand, and 5) new career paths...

  18. Apollo experience report: Guidance and control systems. Engineering simulation program

    Science.gov (United States)

    Gilbert, D. W.

    1973-01-01

    The Apollo Program experience from early 1962 to July 1969 with respect to the engineering-simulation support and the problems encountered is summarized in this report. Engineering simulation in support of the Apollo guidance and control system is discussed in terms of design analysis and verification, certification of hardware in closed-loop operation, verification of hardware/software compatibility, and verification of both software and procedures for each mission. The magnitude, time, and cost of the engineering simulations are described with respect to hardware availability, NASA and contractor facilities (for verification of the command module, the lunar module, and the primary guidance, navigation, and control system), and scheduling and planning considerations. Recommendations are made regarding implementation of similar, large-scale simulations for future programs.

  19. High temperature engineering research facilities and experiments in China

    International Nuclear Information System (INIS)

    Xu, Yuanhui; Liu, Meisheng; Yao, Huizhong; Ju, Huaiming

    1998-01-01

    June 14, 1995, the construction of a pebble bed type high temperature gas-cooled reactor (HTGR) started in China. It is a test reactor with 10 MW thermal power output (termed HTR- 10). The test reactor is located on the site of Institute of Nuclear Energy Technology (INET) of Tsinghua University in the northwest suburb of Beijing, about 40 km away from the city. Design of the HTR-10 test reactor represents the features of HTR-Modular design: 'side-by-side' arrangement, spherical fuel elements with 'multi-pass' loading scheme, completely passive decay heat removal, reactor shutdown systems in the side reflector, etc. However, in the HTR-10 design some modifications from the HTR-Module were made to satisfy Chinese conditions. For example, the steam generator is composed of a number of modular helical tubes with small diameter, pulse pneumatic discharging apparatus are used in the fuel handling system and step motor driving control rods are designed. These modifications would cause some uncertainty in our design. It is necessary to do engineering experiments to prove these new or modified ideas. Therefore, a program of engineering experiments for HTR-10 key technologies is being conducted at INET. The main aims of these engineering experiments are to verify the designed characteristics and performance of the components and systems, to feedback on design and to obtain operational experiences. Those engineering experiments are depressurization test of the hot gas duct at room temperature and operating pressure, performance test of the hot gas duct at operating helium temperature and pressure, performance test of the pulse pneumatic fuel handling system, test of the control rods driving apparatus, two phase flow stability test for the once through steam generator and cross mixture test at the bottom of the reactor core

  20. Focused feasibility study of engineered barriers for waste management units in the 200 areas

    International Nuclear Information System (INIS)

    1996-08-01

    This Focused Feasibility Study (FFS) evaluates a total of four conceptual barrier designs for different types of waste sites. The Hanford Barrier, the Modified RCRA Subtitle C Barrier, and the Modified RCRA Subtitle D Barrier are being considered as the baseline design for the purpose of the FFS evaluation. A fourth barrier design, the Standard RCRA Subtitle C Barrier, is also evaluated in this FFS; it is commonly applied at other waste sites across the country. These four designs provide a range of cover options to minimize health and environmental risks associated with a site and specific waste categories for active design life periods of 30, 100, 500, and 1,000 years. Design criteria for the 500 and 1,000-year design life barriers include design performance to extend beyond active institutional control and monitoring periods

  1. Experience with performance based training of nuclear criticality safety engineers

    International Nuclear Information System (INIS)

    Taylor, R.G.

    1993-01-01

    Historically, new entrants to the practice of nuclear criticality safety have learned their job primarily by on-the-job training (OJT) often by association with an experienced nuclear criticality safety engineer who probably also learned their job by OJT. Typically, the new entrant learned what he/she needed to know to solve a particular problem and accumulated experience as more problems were solved. It is likely that more formalism will be required in the future. Current US Department of Energy requirements for those positions which have to demonstrate qualification indicate that it should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis i's incompletely developed in some areas. Details of this analysis are provided in this report

  2. AN ANALYSIS OF THE THERMAL AND MECHANICAL BEHAVIOR OF ENGINEERED BARRIERS IN A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY

    Directory of Open Access Journals (Sweden)

    S. KWON

    2013-02-01

    Full Text Available Adequate design of engineered barriers, including canister, buffer and backfill, is important for the safe disposal of high-level radioactive waste. Three-dimensional computer simulations were carried out under different condition to examine the thermal and mechanical behavior of engineered barriers and rock mass. The research looked at five areas of importance, the effect of the swelling pressure, water content of buffer, density of compacted bentonite, emplacement type and the selection of failure criteria. The results highlighted the need to consider tensile stress in the outer shell of a canister due to thermal expansion of the canister and the swelling pressure from the buffer for a more reliable design of an underground repository system. In addition, an adequate failure criterion should be used for the buffer and backfill.

  3. An analysis of the thermal and mechanical behavior of engineered barriers in a high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Kwon, S.; Cho, W. J.; Lee, J. O.

    2013-01-01

    Adequate design of engineered barriers, including canister, buffer and backfill, is important for the safe disposal of high level radioactive waste. Three-dimensional computer simulations were carried out under different condition to examine the thermal and mechanical behavior of engineered barriers and rock mass. The research looked at five areas of importance, the effect of the swelling pressure, water content of buffer, density of compacted bentonite, emplacement type and the selection of failure criteria. The results highlighted the need to consider tensile stress in the outer shell of a canister due to thermal expansion of the canister and the swelling pressure from the buffer for a more reliable design of an underground repository system. In addition, an adequate failure criterion should be used for the buffer and backfill.

  4. Effect of thermal barrier coating with various blends of pumpkin seed oil methyl ester in DI diesel engine

    Science.gov (United States)

    Karthickeyan, V.; Balamurugan, P.

    2017-10-01

    The rise in oil prices, dependency on fossil fuels, degradation of non-renewable energy resources and global warming strives to find a low-carbon content alternative fuel to the conventional fuel. In the present work, Partially Stabilized Zirconia (PSZ) was used as a thermal barrier coating in piston head, cylinder head and intake and exhaust valves using plasma spray technique, which provided a rise in combustion chamber temperature. With the present study, the effects of thermal barrier coating on the blends of Pumpkin Seed Oil Methyl Ester (PSOME) were observed in both the coated and uncoated engine. Performance and emission characteristics of the PSOME in coated and uncoated engines were observed and compared. Increased thermal efficiency and reduced fuel consumption were observed for B25 and diesel in coated and uncoated engine. On comparing with the other biodiesel samples, B25 exhibited lower HC, NOx and smoke emissions in thermally coated engine than uncoated engine. After 100 h of operation, no anamolies were found in the thermally coated components except minor cracks were identified in the edges of the piston head.

  5. Performance and emission characteristics of the thermal barrier coated SI engine by adding argon inert gas to intake mixture

    Directory of Open Access Journals (Sweden)

    T. Karthikeya Sharma

    2015-11-01

    Full Text Available Dilution of the intake air of the SI engine with the inert gases is one of the emission control techniques like exhaust gas recirculation, water injection into combustion chamber and cyclic variability, without scarifying power output and/or thermal efficiency (TE. This paper investigates the effects of using argon (Ar gas to mitigate the spark ignition engine intake air to enhance the performance and cut down the emissions mainly nitrogen oxides. The input variables of this study include the compression ratio, stroke length, and engine speed and argon concentration. Output parameters like TE, volumetric efficiency, heat release rates, brake power, exhaust gas temperature and emissions of NOx, CO2 and CO were studied in a thermal barrier coated SI engine, under variable argon concentrations. Results of this study showed that the inclusion of Argon to the input air of the thermal barrier coated SI engine has significantly improved the emission characteristics and engine’s performance within the range studied.

  6. Technical Work Plan for: Near Field Environment: Engineered Barrier System: Radionuclide Transport Abstraction Model Report

    International Nuclear Information System (INIS)

    J.D. Schreiber

    2006-01-01

    This technical work plan (TWP) describes work activities to be performed by the Near-Field Environment Team. The objective of the work scope covered by this TWP is to generate Revision 03 of EBS Radionuclide Transport Abstraction, referred to herein as the radionuclide transport abstraction (RTA) report. The RTA report is being revised primarily to address condition reports (CRs), to address issues identified by the Independent Validation Review Team (IVRT), to address the potential impact of transport, aging, and disposal (TAD) canister design on transport models, and to ensure integration with other models that are closely associated with the RTA report and being developed or revised in other analysis/model reports in response to IVRT comments. The RTA report will be developed in accordance with the most current version of LP-SIII.10Q-BSC and will reflect current administrative procedures (LP-3.15Q-BSC, ''Managing Technical Product Inputs''; LP-SIII.2Q-BSC, ''Qualification of Unqualified Data''; etc.), and will develop related Document Input Reference System (DIRS) reports and data qualifications as applicable in accordance with prevailing procedures. The RTA report consists of three models: the engineered barrier system (EBS) flow model, the EBS transport model, and the EBS-unsaturated zone (UZ) interface model. The flux-splitting submodel in the EBS flow model will change, so the EBS flow model will be validated again. The EBS transport model and validation of the model will be substantially revised in Revision 03 of the RTA report, which is the main subject of this TWP. The EBS-UZ interface model may be changed in Revision 03 of the RTA report due to changes in the conceptualization of the UZ transport abstraction model (a particle tracker transport model based on the discrete fracture transfer function will be used instead of the dual-continuum transport model previously used). Validation of the EBS-UZ interface model will be revised to be consistent with

  7. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Apted, Mick; Arthur, Randy [Monitor Scientific LLC, Denver, CO (United States); Savage, Dave [Quintessa Ltd., Nottingham (GB)] (eds.)

    2005-09-15

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations.

  8. Diffusive Transport of Sulphide through an Engineering Barrier System in a Deep Geological Repository

    Science.gov (United States)

    Briggs, S. A.; Sleep, B. E.; McKelvie, J. R. M.; Krol, M.

    2015-12-01

    Bentonite is a naturally occurring clay-rich sediment containing montmorillonite, a smectitic clay mineral that has a high cation exchange capacity and swells upon contact with water. Owing to these characteristics, highly compacted bentonite (HCB) is an often included component of engineered barrier systems (EBS) designed to protect used fuel containers (UFCs) in deep geological repositories (DGR) for high-level nuclear waste. The low water activity and high swelling pressure of HCB suppresses microbial activity and the related production of sulphide that could cause microbiologically influenced corrosion (MIC) of UFCs The Canadian Nuclear Waste Management Organization (NWMO) has chosen a UFC that consists of an inner steel core and outer copper coating which is resistant to corrosion. However, under anaerobic conditions, MIC can still contribute to UFC corrosion if sulphides are present in the groundwater. Therefore the EBS consisting of bentonite blocks and pellets has been designed to impede the movement of sulphides to the UFC. In order to examine the effectiveness of the EBS, a 3D numerical model was developed capable of simulating the diffusive transport of sulphide within the NWMO EBS. The model was developed using COMSOL Multiphysics, a finite element software package and is parametric which allows the impact of different repository layouts to be assessed. The developed model was of the entire NWMO placement room, as well as, a stand-alone UFC and included conservative assumptions such as a fully saturated system and a constant concentration boundary condition. The results showed that the highest sulphide flux occurred at the semi-spherical end caps of the UFC. Further studies examined the effect of sulphide hotspots and fractures, representing possible EBS failure mechanisms. The model results highlight that even with conservative assumptions the chosen EBS will effectively protect the UFC from microbiologically influenced corrosion.

  9. Engineered Barrier System - Long-term Stability of Buffer and Backfill. Synthesis and extended abstracts

    International Nuclear Information System (INIS)

    Apted, Mick; Arthur, Randy; Savage, Dave

    2005-09-01

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for an encapsulation plant and a deep repository for the geological disposal of spent nuclear fuel. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS) of the repository. This workshop concerns the longterm stability of the buffer and the backfill. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS and the performance confirmation for the EBS. The goal of this work is to achieve a comprehensive overview of all aspects of SKB's EBS work prior to the handling of forthcoming license applications. The reports from the EBS workshops will be used as one important basis in future review work. The workshops involve the gathering of a sufficient number of independent experts in different subjects of relevance to the particular aspect of EBS. A workshop starts with presentations and discussions among these experts. Following this, SKB presents recent results and responds to questions as part of an informal hearing. Finally, the independent experts and the SKI staff examine the SKB responses from different viewpoints. This report aims to summarise the issues discussed at the buffer and backfill workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of the discussions and individual statements made by workshop participants should be regarded as opinions rather than proven facts. This reports includes apart from the workshop synthesis, questions to SKB identified prior or during the workshop, and extended abstracts for introductory presentations

  10. A multi-purpose unit concept to integrate storage, transportation, and the engineered barrier system

    International Nuclear Information System (INIS)

    Hollaway, W.R.; Rozier, R.; Nitti, D.A.; Williams, J.R.

    1993-01-01

    The Multi-Purpose Unit (MPU) is a new concept for standardizing and integrating the waste management functions of spent fuel storage, transportation, and geologic disposal. The MPU concept would use one unit, composed of a relatively thick-walled inner canister with a multi-purpose overpack, to meet the requirements for storage in 10 CFR 72, transportation in 10 CFR 71, and the engineered barrier system in 10 CFR 60. The MPU concept differs from the recently proposed Multi-Purpose Canister (MPC) concept in that the MPU concept uses a single multi-purpose overpack for storage, transportation, and geologic disposal, while the MPC concept uses separate and unique overpacks for each of these system functions. A design concept for the MPU is presented along with an estimate of unit costs. An initial evaluation of overall system cost showed that the MPU concept could be economically competitive with the current reference system. The MPU concept provides the potential for significant reduction, simplification, and standardization of Civilian Radioactive Waste Management (CRWMS) facilities and operations, including those at the utilities, during waste acceptance and transportation, and at the Monitored Retrievable Storage (MRS) facility and the repository. The primary issues for the MPU concept relate to uncertainties with respect to licensing, and the programmatic risks associated with implementing the MPU concept before the repository design is finalized. The strong potential exhibited by the MPU concept demonstrates that this option merits additional development and should be considered in the next phase of work on multi-purpose concepts for the CRWMS

  11. Engineering Physics Division integral experiments and their analyses

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Integral experiments are performed as part of the Engineering Physics Division's on-going research in the development and application of radiation shielding methods. Integral experiments performed at the Oak Ridge Electron Linear Accelerator (ORELA) under the Division's Magnetic Fusion program are designed to provide data against which ORNL and all other organizations involved in shielding calculations for fusion devices can test their calculational methods and interaction data. The Tower Shielding Facility (TSF) continues to be the primary source of integral data for fission reactor shielding design. The experiments performed at the TSF during the last few years have been sponsored by the Gas Cooled Fast Reactor (GCFR) program. During this report period final documentation was also prepared for the remaining LMFBR shielding experiments, including an examination of streaming through annular slits and measurement of secondary gamma-ray production in reinforced concrete

  12. Technical note. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

    Energy Technology Data Exchange (ETDEWEB)

    Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex [Quintessa Ltd, Henley on Thames (United Kingdom)

    2012-11-01

    This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible

  13. Experiments on Plume Spreading by Engineered Injection and Extraction

    Science.gov (United States)

    Mays, D. C.; Jones, M.; Tigera, R. G.; Neupauer, R.

    2014-12-01

    The notion that groundwater remediation is transport-limited emphasizes the coupling between physical (i.e., hydrodynamic), geochemical, and microbiological processes in the subsurface. Here we leverage this coupling to promote groundwater remediation using the approach of engineered injection and extraction. In this approach, inspired by the literature on chaotic advection, uncontaminated groundwater is injected and extracted through a manifold of wells surrounding the contaminated plume. The potential of this approach lies in its ability to actively manipulate the velocity field near the contaminated plume, generating plume spreading above and beyond that resulting from aquifer heterogeneity. Plume spreading, in turn, promotes mixing and reaction by chemical and biological processes. Simulations have predicted that engineered injection and extraction generates (1) chaotic advection whose characteristics depend on aquifer heterogeneity, and (2) faster rates and increased extent of groundwater remediation. This presentation focuses on a complimentary effort to experimentally demonstrate these predictions experimentally. In preparation for future work using refractive index matched (RIM) porous media, the experiments reported here use a Hele-Shaw apparatus containing silicone oil. Engineered injection and extraction is used to manipulate the geometry of an initially circular plume of black pigment, and photographs record the plume geometry after each step of injection of extraction. Image analysis, using complimentary Eulerian and Lagrangian approaches, reveals the thickness and variability of the dispersion zone surrounding the deformed plume of black pigment. The size, shape, and evolution of this dispersion zone provides insight into the interplay between engineered injection and extraction, which generates plume structure, and dispersion (here Taylor dispersion), which destroys plume structure. These experiments lay the groundwork for application of engineered

  14. Women withdrawers in engineering studies : identity formation and learning culture as gendered barriers for persistence?

    OpenAIRE

    Wolffram, Andrea; Derboven, Wibke; Winker, Gabriele

    2009-01-01

    Scholarship on women in engineering education mainly focuses on the question of how to attract more women to this subject. The topic concerning women in engineering education is here guided by the question of why women leave engineering studies. The paper aims to examine the main conflicts women encounter in engineering education and to derive implications for interventions suited for strengthening institutional bonding forces.

  15. Recent experimental progress in the TMX-U thermal barrier tandem mirror experiment

    International Nuclear Information System (INIS)

    Turner, W.C.; Allen, S.L.; Casper, T.A.

    1984-01-01

    Recent experiments on the TMX-U thermal barrier device at LLNL have achieved the end plugging of axial ion losses up to a central cell density of n/sub c/ = 2 x 10 12 cm. During these tests, the axial potential profile characteristic of a thermal barrier has been measured experimentally, indicating an ion-confining potential greater than 1.5 kV and a potential depression of 0.45 kV in the barrier region. The average beta of hot electrons in the thermal barrier has been increased to 15% and appears limited only by classical scattering and ECRH pulse duration. Furthermore, deuterium ions in the central cell have been heated with ICRF to an average energy of 1.5 keV, with a heating efficiency of 40%. During strong end plugging, the axial ion confinement time reached 50 to 100 ms while the nonambipolar radial ion confinement time was 5 to 15 ms - independent of end plugging. Radial ion confinement time exceeding 100 ms has been attained on shots without end plugging. Plates, floated electrically on the end walls, have increased the radial ion confinement time by a factor of 1.8. Further improvement in the central cell density during end plugging can be expected by increasing the ICRF, improving the central cell vacuum conditions and beam heating efficiency, and increasing the radial extent of the potential control plates on the end walls

  16. TMX tandem-mirror experiments and thermal-barrier theoretical studies

    International Nuclear Information System (INIS)

    Simonen, T.C.; Baldwin, D.E.; Allen, S.L.

    1982-01-01

    This paper describes recent analysis of energy confinement in the Tandem Mirror Experiment (TMX). TMX data also indicates that warm plasma limits the amplitude of the anisotropy driven Alfven ion cyclotron (AIC) mode. Theoretical calculations show strong AIC stabilization with off-normal beam injection as planned in TMX-U and MFTF-B. This paper reports results of theoretical analysis of hot electrons in thermal barriers including electron heating calculations by Monte Carlo and Fokker-Planck codes and analysis of hot electron MHD and microinstability. Initial results from the TMX-U experiment are presented which show the presence of sloshing ions

  17. Current status of gas migration and swelling experiments using engineering scale model for immediate depth disposal in Japan

    International Nuclear Information System (INIS)

    Higashihara, Tomohiro; Ono, Makoto; Kawaragi, Chie; Saito, Shigeyuki

    2010-01-01

    In intermediate depth disposal facility of radioactive waste in Japan, waste is surrounded with bentonite layer to retard interaction of the waste and groundwater, because the bentonite layer saturated with the groundwater has very low hydraulic conductivity. On the other hand, it is important to confirm stability of barrier system for stress generated together with swelling of the bentonite and to understand effect of increase of gas pressure because of generation of hydrogen gas by corrosion of metallic waste. To understand and evaluate the swelling behavior of the bentonite layer, JNES carries out the experiment. In the experiments, we carry out the swelling experiment to examine the swelling behavior of the bentonite layer and the gas migration experiment to understand the gas migration behavior in the bentonite layer, using engineering scale model of the disposal facility. The swelling experiment has been in operation since June 2010. After this experiment, the gas migration experiment will start in July 2011. (orig.)

  18. The influence of interfacial barrier engineering on the resistance switching of In2O3:SnO2/TiO2/In2O3:SnO2 device

    International Nuclear Information System (INIS)

    Liu Zi-Yu; Zhang Pei-Jian; Meng Yang; Li Dong; Meng Qing-Yu; Li Jian-Qi; Zhao Hong-Wu

    2012-01-01

    The I—V characteristics of In 2 O 3 :SnO 2 /TiO 2 /In 2 O 3 :SnO 2 junctions with different interfacial barriers are investigated by comparing experiments. A two-step resistance switching process is found for samples with two interfacial barriers produced by specific thermal treatment on the interfaces. The nonsynchronous occurrence of conducting filament formation through the oxide bulk and the reduction in the interfacial barrier due to the migration of oxygen vacancies under the electric field is supposed to explain the two-step resistive switching process. The unique switching properties of the device, based on interfacial barrier engineering, could be exploited for novel applications in nonvolatile memory devices. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  19. Collaboration for cooperative work experience programs in biomedical engineering education.

    Science.gov (United States)

    Krishnan, Shankar

    2010-01-01

    Incorporating cooperative education modules as a segment of the undergraduate educational program is aimed to assist students in gaining real-life experience in the field of their choice. The cooperative work modules facilitate the students in exploring different realistic aspects of work processes in the field. The track records for cooperative learning modules are very positive. However, it is indeed a challenge for the faculty developing Biomedical Engineering (BME) curriculum to include cooperative work experience or internship requirements coupled with a heavy course load through the entire program. The objective of the present work is to develop a scheme for collaborative co-op work experience for the undergraduate training in the fast-growing BME programs. A few co-op/internship models are developed for the students pursuing undergraduate BME degree. The salient features of one co-op model are described. The results obtained support the proposed scheme. In conclusion, the cooperative work experience will be an invaluable segment in biomedical engineering education and an appropriate model has to be selected to blend with the overall training program.

  20. Evaluation of Subsurface Engineered Barriers at Waste Sites Volumes 1 and 2

    Science.gov (United States)

    This report provides the U.S. Environmental Protection Agency’s (EPA) waste programs with a national retrospective analysis of barrier field performance, as well as information that useful in developing guidance on the use and evaluation of barrier systems

  1. Thermal barrier confinement experiments in TMX-U tandem mirror. Revision 1

    International Nuclear Information System (INIS)

    Simonen, T.C.; Allen, S.L.; Baldwin, D.E.

    1984-01-01

    In our recent experiments on the TMX-U thermal-barrier device, we achieved the end plugging of axial ion losses up to a central cell density of n/sub c/ = 6 x 10 12 cm -3 . During lower density experiments, we measured the axial potential profile characteristic of a thermal barrier and found an ion-confining potential greater than 1.5 kV and a potential depression of 0.45 kV in the barrier region. The average beta of hot end plug electrons has reached 15% and of hot central cell ions has reached 6%. In addition, we heated deuterium ions in the central cell with ICRF to an average perpendicular energy of 2 keV. During strong end plugging at low density (7 x 10 11 cm -3 ), the axial ion confinement time tau/sub parallel to/ reached 50 to 100 ms while the nonambiopolar radial ion confinement time tau/sub perpendicular to/ was 14 ms - independent of end plugging. Electrically floating end walls doubled the radial ion confinement time. At higher densities and lower potentials, tau/sub parallel to/ was 6 to 12 ms and tau/sub perpendicular to/ exceeded 100 ms

  2. Engineering aspects of the Stanford relativity gyro experiment

    Science.gov (United States)

    Everitt, C. W. F.; Debra, D. B.

    1981-01-01

    According to certain theoretical predictions, the Newtonian laws of motion must be corrected for the effect of a gravitational field. Schiff (1960) proposed an experiment which would demonstrate the effect predicted by Einstein's Theory of General Relativity on a gyroscope. The experiment has been under development at Stanford University since 1961. The requirements involved make it necessary that the test be performed in a satellite to take advantage of weightlessness in space. In a discussion of engineering developments related to the experiment, attention is given to the development of proportional helium thrusters, the simulation of the attitude control system, aspects of inner loop control, the mechanization of the two-loop attitude control system, the effects of helium slosh on spacecraft pointing, and the data instrumentation system.

  3. Modeling the Hydrogeochemical Transport of Radionuclides through Engineered Barriers System in the Proposed LLW Disposal Site of Taiwan - 12082

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taipei, Taiwan (China); Liu, Chen-Wuing; Tsao, Jui-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Jhongli, Taiwan (China)

    2012-07-01

    A proposed site for final disposal of low-level radioactive waste located in Daren Township of Taitung County along the southeastern coast has been on the selected list in Taiwan. The geology of the Daren site consists of argillite and meta-sedimentary rocks. A mined cavern design with a tunnel system of 500 m below the surface is proposed. Concrete is used as the main confinement material for the engineered barrier. To investigate the hydrogeochemical transport of radionuclides through engineered barriers system, HYDROGEOCHEM5.0 model was applied to simulate the complex chemical interactions among radionuclides, the cement minerals of the concrete, groundwater flow, and transport in the proposed site. The simulation results showed that the engineered barriers system with the side ditch efficiently drained the ground water and lowered the concentration of the concrete degradation induced species (e.g., hydrogen ion, sulfate, and chloride). The velocity of groundwater observed at side ditch gradually decreased with time due to the fouling of pore space by the mineral formation of ettringite and thaumasite. The short half-life of Co-60, Sr-90 and Cs-137 significantly reduced the concentrations, whereas the long half-life of I-129(1.57x10{sup 7} years) and Am-241(432 years) remain stable concentrations at the interface of waste canister and concrete barrier after 300 years. The mineral saturation index (SI) was much less than zero due to the low aqueous concentration of radionuclide, so that the precipitation formation of Co-60, Sr-90, I-129, Cs-137 and Am-241 related minerals were not found. The effect of adsorption/desorption (i.e., surface complexation model) could be a crucial geochemical mechanism for the modeling of liquid-solid phase behavior of radionuclide in geochemically dynamic environments. Moreover, the development of advanced numerical models that are coupled with hydrogeochemical transport and dose assessment of radionuclide is required in the future

  4. Servant leadership: a phenomenological study of practices, Experiences, organizational effectiveness and barriers

    Directory of Open Access Journals (Sweden)

    Amy R. Savage-Austin, PhD

    2013-07-01

    Full Text Available The subject of leadership is complex, and one of the main issues facing organizational leaders today is how to motivate employees to actively participate in the efforts that lead to accomplishing organizational goals. This study gathered lived experiences of 15 organizational leaders who practice the servant leadership philosophy, and explored how business leaders link their servant leadership practices to their organization’s effectiveness. The qualitative responses obtained during this study indicated that the perceived organizational barriers that prevent the servant leadership practices are the organization’s culture, the fear of change, and the lack of knowledge regarding the servant leadership philosophy. This study also gained insight into the impact that these organizational barriers have on one’s ability to practice servant leadership

  5. Use of radial basis functions for meshless numerical solutions applied to financial engineering barrier options

    Directory of Open Access Journals (Sweden)

    Gisele Tessari Santos

    2009-08-01

    Full Text Available A large number of financial engineering problems involve non-linear equations with non-linear or time-dependent boundary conditions. Despite available analytical solutions, many classical and modified forms of the well-known Black-Scholes (BS equation require fast and accurate numerical solutions. This work introduces the radial basis function (RBF method as applied to the solution of the BS equation with non-linear boundary conditions, related to path-dependent barrier options. Furthermore, the diffusional method for solving advective-diffusive equations is explored as to its effectiveness to solve BS equations. Cubic and Thin-Plate Spline (TPS radial basis functions were employed and evaluated as to their effectiveness to solve barrier option problems. The numerical results, when compared against analytical solutions, allow affirming that the RBF method is very accurate and easy to be implemented. When the RBF method is applied, the diffusional method leads to the same results as those obtained from the classical formulation of Black-Scholes equation.Muitos problemas de engenharia financeira envolvem equações não-lineares com condições de contorno não-lineares ou dependentes do tempo. Apesar de soluções analíticas disponíveis, várias formas clássicas e modificadas da conhecida equação de Black-Scholes (BS requerem soluções numéricas rápidas e acuradas. Este trabalho introduz o método de função de base radial (RBF aplicado à solução da equação BS com condições de contorno não-lineares relacionadas a opções de barreira dependentes da trajetória. Além disso, explora-se o método difusional para solucionar equações advectivo-difusivas quanto à sua efetividade para solucionar equações BS. Utilizam-se funções de base radial Cúbica e Thin-Plate Spline (TPS, aplicadas à solução de problemas de opções de barreiras. Os resultados numéricos, quando comparados com as soluções analíticas, permitem afirmar

  6. Thermal barrier coatings: Coating methods, performance, and heat engine applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning conference proceedings on coating methods, performance evaluations, and applications of thermal barrier coatings as protective coatings for heat engine components against high temperature corrosions and chemical erosions. The developments of thermal barrier coating techniques for high performance and reliable gas turbines, diesel engines, jet engines, and internal combustion engines are presented. Topics include plasma sprayed coating methods, yttria stabilized zirconia coatings, coating life models, coating failure and durability, thermal shock and cycling, and acoustic emission analysis of coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  7. Thermal barrier coatings: Coating methods, performance, and heat engine applications. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The bibliography contains citations concerning conference proceedings on coating methods, performance evaluations, and applications of thermal barrier coatings as protective coatings for heat engine components against high temperature corrosions and chemical erosions. The developments of thermal barrier coating techniques for high performance and reliable gas turbines, diesel engines, jet engines, and internal combustion engines are presented. Topics include plasma sprayed coating methods, yttria stabilized zirconia coatings, coating life models, coating failure and durability, thermal shock and cycling, and acoustic emission analysis of coatings. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  8. Undergraduate engineering student experiences: Comparing sex, gender and switcher status

    Science.gov (United States)

    Fergen, Brenda Sue

    This dissertation explores undergraduate engineering experiences, comparing men with women and switchers with non-switchers. Factors related to a chilly academic climate and gender-role socialization are hypothesized to contribute to variations in men's and women's academic experiences and persistence rates. Both quantitative and qualitative data are utilized in an effort to triangulate the findings. Secondary survey data, acquired as result of a 1992 Academic Environment Survey, were utilized to test the hypothesis that sex is the most important predictor (i.e., demographic variable) of perceptions of academic climate. Regression analyses show that sex by itself is not always a significant determinant. However, when sex and college (engineering vs. other) are combined into dummy variables, they are statistically significant in models where sex was not significant alone. This finding indicates that looking at sex differences alone may be too simplistic. Thirty personal interviews were conducted with a random stratified sample of undergraduate students from the 1993 engineering cohort. The interview data indicate that differences in childhood socialization are important. With regard to persistence, differences in socialization are greater for switchers vs. non-switchers than men vs. women. Thus, gender-role socialization does not appear to play as prominent a role in women's persistence as past literature would indicate. This may be due to the self-selection process that occurs among women who choose to pursue engineering. Other aspects of childhood socialization such as parents' level of educational and occupation, students' high school academic preparation and knowledge of what to expect of college classes appear to be more important. In addition, there is evidence that, for women, male siblings play an important role in socialization. There is also evidence that women engineering students at Midwestern University face a chilly academic climate. The factors which

  9. Experiences of high school Hispanic girls in pursuit of science, technology, engineering, and mathematics-related coursework and careers

    Science.gov (United States)

    Vijil, Veronica G.

    2011-12-01

    An overall increased awareness of the importance of science, technology, engineering, and mathematics (STEM) has prompted attention toward the continued underrepresentation of Hispanic women in this field. The purpose of this collective case study was to explore the support systems, perceived barriers, and prior experiences influencing high school Hispanic girls' decisions to pursue advanced coursework and related careers through a career pathway in science, technology, engineering, and mathematics (STEM) areas. Specifically, participants were interviewed regarding their mathematics and science experiences in elementary and middle schools, as well as perceived supports and barriers to their choices to pursue STEM careers and advanced coursework. Results indicated that the participants linked their elementary and middle school experiences with their teachers rather than specific activities. Accolades such as certificates and good grades for academic achievement contributed to the girls' strong self-efficacy at an early age. The participants possessed self-discipline and self-confidence, using intrinsic motivation to pursue their goals. Support systems included families and a few teachers. Barriers were revealed in different forms including derogatory comments by boys in class, difficult curricula with limited tutors available for higher level courses, and receipt of financial assistance to attend a university of their choice.

  10. Coupled heat transfer model and experiment study of semitransparent barrier materials in aerothermal environment

    Science.gov (United States)

    Wang, Da-Lin; Qi, Hong

    Semi-transparent materials (such as IR optical windows) are widely used for heat protection or transfer, temperature and image measurement, and safety in energy , space, military, and information technology applications. They are used, for instance, ceramic coatings for thermal barriers of spacecrafts or gas turbine blades, and thermal image observation under extreme or some dangerous environments. In this paper, the coupled conduction and radiation heat transfer model is established to describe temperature distribution of semitransparent thermal barrier medium within the aerothermal environment. In order to investigate this numerical model, one semi-transparent sample with black coating was considered, and photothermal properties were measured. At last, Finite Volume Method (FVM) was used to solve the coupled model, and the temperature responses from the sample surfaces were obtained. In addition, experiment study was also taken into account. In the present experiment, aerodynamic heat flux was simulated by one electrical heater, and two experiment cases were designed in terms of the duration of aerodynamic heating. One case is that the heater irradiates one surface of the sample continually until the other surface temperature up to constant, and the other case is that the heater works only 130 s. The surface temperature responses of these two cases were recorded. Finally, FVM model of the coupling conduction-radiation heat transfer was validated based on the experiment study with relative error less than 5%.

  11. PERFORMANCE ANALYSIS OF 1,4 DIOXANE-ETHANOL-DIESEL BLENDS ON DIESEL ENGINES WITH AND WITHOUT THERMAL BARRIER COATING

    Directory of Open Access Journals (Sweden)

    Chockalingam Sundar Raj

    2010-01-01

    Full Text Available 1,4 dioxane, a new additive allows the splash blending of ethanol in diesel in a clear solution. The objective of this investigation is to first create a stable ethanol-diesel blended fuel with 10% 1,4 dioxane additive, and then to generate performance, combustion and emissions data for evaluation of different ethanol content on a single cylinder diesel engine with and without thermal barrier coating. Results show improved performance with blends compared to neat fuel for all conditions of the engine. Drastic reduction in smoke density is found with the blends as compared to neat diesel and the reduction is still better for coated engine. NOx emissions were found to be high for coated engines than the normal engine for the blends. The oxygen enriched fuel increases the peak pressure and rate of pressure rise with increase in ethanol ratio and is still superior for coated engine. Heat release pattern shows higher premixed combustion rate with the blends. Longer ignition delay and shorter combustion duration are found with all blends than neat diesel fuel.

  12. Modelling Coupled Processes in the Evolution of Repository Engineered Barrier Systems using QPAC-EBS

    Energy Technology Data Exchange (ETDEWEB)

    Maul, Philip; Benbow, Steven; Bond, Alex; Robinson, Peter (Quintessa Limited, Henley-on-Thames (United Kingdom))

    2010-08-15

    A satisfactory understanding of the evolution of repository engineered barrier systems (EBS) is an essential part of the safety case for the repository. This involves consideration of coupled Thermal (T), Hydro (H), Mechanical (M) and Chemical (C) processes. Quintessa's general-purpose modelling code QPAC is capable of representing strongly coupled non-linear processes and has been used in a wide range of applications. This code is the basis for software used by Quintessa in studies of the evolution of the EBS in a deep repository for spent nuclear fuel undertaken for SKI and then SSM since 2007. The collection of software components employed has been referred to collectively as QPAC-EBS, consisting of the core QPAC code together with relevant modules for T, H, M and C processes. QPAC-EBS employs a fundamentally different approach from dedicated codes that model such processes (although few codes can represent each type of process), enabling the specification of new processes and the associated governing equations in code input. Studies undertaken to date have demonstrated that QPAC-EBS can be used effectively to investigate both the early evolution of the EBS and important scenarios for the later evolution of the system when buffer erosion and canister corrosion may occur. A key issue for modelling EBS evolution is the satisfactory modelling of the behaviour of the bentonite buffer. Bentonite is a difficult material to model, partly because of the complex coupled mechanical, hydro and chemical processes involved in swelling during resaturation. Models employed to date have generally taken an empirical approach, but a new model developed during the EU THERESA project could be further developed to provide a better representation of these processes. QPAC-EBS could play an important role in supporting SSM.s review of the forthcoming SR-Site assessment by SKB if used by Quintessa in independent supporting calculations. To date radionuclide transport calculations

  13. Evaluating Admission Practices as Potential Barriers to Creating Equitable Access to Undergraduate Engineering Education

    Science.gov (United States)

    Myers, Beth Ann

    2016-01-01

    To create a more competitive and creative engineering workforce, breakthroughs in how we attract and educate more diverse engineers are mandated. Despite a programmatic focus on increasing the representation of women and minorities in engineering during the last few decades, no single solution has been identified and is probably not realistic. But…

  14. The experiences of women engineers who have completed one to five years of professional engineering employment: A phenomenological study

    Science.gov (United States)

    White, Susan M.

    Women engineers remain underrepresented in employment in engineering fields in the United States. Feminist theory views this gender disparity beyond equity in numbers for women engineers and looks at structural issues of women's access, opportunities, and quality of experience in the workplace. Research on women's success and persistence in engineering education is diverse; however, there are few studies that focus on the early years of women's careers in engineering and less using a phenomenological research design. Experiences of women engineers who have completed one to five years of professional engineering employment are presented using a phenomenological research design. Research questions explored the individual and composite experiences for the co-researchers of the study as well as challenges and advantages of the phenomenon of having completed one to five years of professional engineering employment. Themes that emanated from the data were a feeling that engineering is a positive profession, liking math and science from an early age, having experiences of attending math and science camps or learning and practicing engineering interests with their fathers for some co-researchers. Other themes included a feeling of being different as a woman in the engineering workplace, taking advantage of opportunities for training, education, and advancement to further their careers, and the role of informal and formal mentoring in developing workplace networks and engineering expertise. Co-researchers negotiated issues of management quality and support, experiences of gender discrimination in the workplace, and having to make decisions balancing their careers and family responsibilities. Finally, the women engineers for this research study expressed intentions to persist in their careers while pursuing expertise and experience in their individual engineering fields.

  15. Identity physics experiment on internal transport barriers in JT-60U and JET

    Energy Technology Data Exchange (ETDEWEB)

    De Vries, P C; Beurskens, M N A; Brix, M; Giroud, C; Hawkes, N C; Parail, V [EURATOM/UKAEA Association, Culham Science Centre, OX14 3DB, Abingdon (United Kingdom); Sakamoto, Y; Fujita, T; Hayashi, N; Matsunaga, G; Oyama, N; Shinohara, K; Suzuki, T; Takechi, M [Japan Atomic Energy Agency, Naka, Ibaraki-ken 311-0193 (Japan); Litaudon, X; Joffrin, E [CEA, IRFM, F-13108 St-Paul-Lez-Durance (France); Crombe, K [Department of Applied Physics, Ghent University, Rozier 44, 9000 Gent (Belgium); Mantica, P [Istituto di Fisica del Plasma, EURATOM/ENEA-CNR Association, Milano (Italy); Salmi, A [Association Euratom-Tekes, Helsinki University of Technology, PO Box 4100 (Finland); Strintzi, D, E-mail: Peter.de.Vries@jet.u [National Technical University of Athens, EURATOM Association, GR-15773, Athens (Greece)

    2009-12-15

    A series of experiments have been carried out in 2008 at JT-60U and JET to find common characteristics and explain differences between internal transport barriers (ITBs). The identity experiments succeeded in matching the profiles of most dimensionless parameters at the time ITBs were triggered. Thereafter the q-profile development deviated due to differences in non-inductive current density profile, affecting the ITB. Furthermore, the ITBs in JET were more strongly influenced by the H-mode pedestal or edge localized modes. It was found to be difficult to match the plasma rotation characteristics in both devices. However, the wide range of Mach numbers obtained in these experiments shows that the rotation has little effect on the triggering of ITBs in plasmas with reversed magnetic shear. On the other hand the toroidal rotation and more specifically the rotational shear had an impact on the subsequent growth and allowed the formation of strong ITBs.

  16. EXPERIENCE OF BARRIERS TO HYPERTENSION MANAGEMENT IN MINANGKABAU ETHNIC GROUP IN PAYAKUMBUH INDONESIA: A PHENOMENOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Vera Kurnia

    2018-05-01

    Full Text Available Background: Understanding barriers to hypertension managements remains important to reduce the hypertension rate in community. Minangkabau is one of the ethnic groups in West Sumatra Indonesia that has a high proportion of people with hypertension although its management has been implemented. Objective: This study aims to explore the experiences of barriers to hypertension management in Minangkabau ethnic group in Payakumbuh, Indonesia. Methods: This was a phenomenological study with twelve respondents selected using purposive sampling. Data were collected using in-depth interview. Colaizzi’s content analysis method was used for data analysis. Results: Five themes were emerged from the data, namely: (i lack of self-motivation in the management of hypertension, (ii disobedience in the management of hypertension, (iii culture pattern of food intake, (iv lack of social support, and (v excessive stress and anxiety. Conclusions: The barriers to hypertension management in Minangkabau ethnic group are closely related to its culture both in lifestyle and in food intake of the family members and the community. Nurses are expected toalways give health education about hypertension and finding the way to control it.

  17. Violence Against Widows in Nepal: Experiences, Coping Behaviors, and Barriers in Seeking Help.

    Science.gov (United States)

    Sabri, Bushra; Sabarwal, Shrutika; Decker, Michele R; Shrestha, Abina; Sharma, Kunda; Thapa, Lily; Surkan, Pamela J

    2016-05-01

    Widows are a vulnerable population in Nepal. This study examined Nepalese widows' experiences of violence, their coping strategies, and barriers faced in seeking help. Study participants were recruited from Women for Human Rights, an NGO in Nepal. A stratified purposive sampling approach was used to select 51 widows and 5 staff members for in-depth interviews. Twenty-seven women who experienced violence were included in this analysis. Data were analyzed and synthesized using a thematic analysis procedure. Widows reported a range of violent experiences perpetrated by family and community members that spanned psychological, physical, and sexual abuse. Women dealt with abusive experiences using both adaptive (e.g., attempting to move ahead, seeking social support, using verbal confrontation) and maladaptive coping strategies (e.g., suicidal thoughts or self-medication). However, they faced barriers to seeking help such as insensitivity of the police, perceived discrimination, and general lack of awareness of widows' problems and needs. Findings highlight the need for interventions across the individual, family, community, and policy levels. Avenues for intervention include creating awareness about widows' issues and addressing cultural beliefs affecting widows' lives. Furthermore, efforts should focus on empowering widows, promoting healthy coping, and addressing their individual needs. © The Author(s) 2015.

  18. Aerospace Ceramic Materials: Thermal, Environmental Barrier Coatings and SiC/SiC Ceramic Matrix Composites for Turbine Engine Applications

    Science.gov (United States)

    Zhu, Dongming

    2018-01-01

    Ceramic materials play increasingly important roles in aerospace applications because ceramics have unique properties, including high temperature capability, high stiffness and strengths, excellent oxidation and corrosion resistance. Ceramic materials also generally have lower densities as compared to metallic materials, making them excellent candidates for light-weight hot-section components of aircraft turbine engines, rocket exhaust nozzles, and thermal protection systems for space vehicles when they are being used for high-temperature and ultra-high temperature ceramics applications. Ceramic matrix composites (CMCs), including non-oxide and oxide CMCs, are also recently being incorporated in gas turbine engines for high pressure and high temperature section components and exhaust nozzles. However, the complexity and variability of aerospace ceramic processing methods, compositions and microstructures, the relatively low fracture toughness of the ceramic materials, still remain the challenging factors for ceramic component design, validation, life prediction, and thus broader applications. This ceramic material section paper presents an overview of aerospace ceramic materials and their characteristics. A particular emphasis has been placed on high technology level (TRL) enabling ceramic systems, that is, turbine engine thermal and environmental barrier coating systems and non-oxide type SiC/SiC CMCs. The current status and future trend of thermal and environmental barrier coatings and SiC/SiC CMC development and applications are described.

  19. Tissue engineering of heart valves: in vitro experiences.

    Science.gov (United States)

    Sodian, R; Hoerstrup, S P; Sperling, J S; Daebritz, S H; Martin, D P; Schoen, F J; Vacanti, J P; Mayer, J E

    2000-07-01

    Tissue engineering is a new approach, whereby techniques are being developed to transplant autologous cells onto biodegradable scaffolds to ultimately form new functional tissue in vitro and in vivo. Our laboratory has focused on the tissue engineering of heart valves, and we have fabricated a trileaflet heart valve scaffold from a biodegradable polymer, a polyhydroxyalkanoate. In this experiment we evaluated the suitability of this scaffold material as well as in vitro conditioning to create viable tissue for tissue engineering of a trileaflet heart valve. We constructed a biodegradable and biocompatible trileaflet heart valve scaffold from a porous polyhydroxyalkanoate (Meatabolix Inc, Cambridge, MA). The scaffold consisted of a cylindrical stent (1 x 15 x 20 mm inner diameter) and leaflets (0.3 mm thick), which were attached to the stent by thermal processing techniques. The porous heart valve scaffold (pore size 100 to 240 microm) was seeded with vascular cells grown and expanded from an ovine carotid artery and placed into a pulsatile flow bioreactor for 1, 4, and 8 days. Analysis of the engineered tissue included biochemical examination, enviromental scanning electron microscopy, and histology. It was possible to create a trileaflet heart valve scaffold from polyhydroxyalkanoate, which opened and closed synchronously in a pulsatile flow bioreactor. The cells grew into the pores and formed a confluent layer after incubation and pulsatile flow exposure. The cells were mostly viable and formed connective tissue between the inside and the outside of the porous heart valve scaffold. Additionally, we demonstrated cell proliferation (DNA assay) and the capacity to generate collagen as measured by hydroxyproline assay and movat-stained glycosaminoglycans under in vitro pulsatile flow conditions. Polyhydroxyalkanoates can be used to fabricate a porous, biodegradable heart valve scaffold. The cells appear to be viable and extracellular matrix formation was induced

  20. Assessment of Barriers to Providing Introductory Pharmacy Practice Experiences (IPPEs in the Hospital Setting

    Directory of Open Access Journals (Sweden)

    Matthew J Gibson

    2016-07-01

    Full Text Available Objectives: The primary objective of the study is to identify the barriers to providing Introductory Pharmacy Practice Experiences (IPPEs in the hospital setting. Methods: Potential barriers to IPPEs were identified via literature review and interviews with current IPPE preceptors from various institutions. Based on this information, an electronic survey was developed and distributed to IPPE preceptors in order to assess student, preceptor, logistical and college or school of pharmacy related barriers that potentially exist for providing IPPE in the hospital setting. Results: Sixty-eight of the 287 eligible survey respondents (24% completed the electronic survey. Seventy-six percent of respondents agreed or strongly agreed that available time was a barrier to precepting IPPE students even though a majority of respondents reported spending a third or more of their day with an IPPE student when on rotation. Seventy-three percent of respondents disagreed or strongly disagreed that all preceptors have consistent performance expectations for students, while just 46% agreed or strongly agreed that they had adequate training to precept IPPEs. Sixty-five percent of respondents agreed that IPPE students have the ability to be a participant in patient care and 70% of preceptors believe that IPPE students should be involved in patient care. Conclusions: Conducting IPPEs in the institutional setting comes with challenges. Based on the results of this study, experiential directors and colleges/schools of pharmacy could make a positive impact on the quality and consistency of IPPEs by setting student expectations and training preceptors on appropriate and consistent expectations for students.   Type: Original Research

  1. Three integrated photovoltaic/sound barrier power plants. Construction and operational experience

    International Nuclear Information System (INIS)

    Nordmann, T.; Froelich, A.; Clavadetscher, L.

    2002-01-01

    After an international ideas competition by TNC Switzerland and Germany in 1996, six companies where given the opportunity to construct a prototype of their newly developed integrated PV-sound barrier concepts. The main goal was to develop highly integrated concepts, allowing the reduction of PV sound barrier systems costs, as well as the demonstration of specific concepts for different noise situations. This project is strongly correlated with a German project. Three of the concepts of the competition are demonstrated along a highway near Munich, constructed in 1997. The three Swiss installations had to be constructed at different locations, reflecting three typical situations for sound barriers. The first Swiss installation was the world first Bi-facial PV-sound barrier. It was built on a highway bridge at Wallisellen-Aubrugg in 1997. The operational experience of the installation is positive. But due to the different efficiencies of the two cell sides, its specific yield lies somewhat behind a conventional PV installation. The second Swiss plant was finished in autumn 1998. The 'zig-zag' construction is situated along the railway line at Wallisellen in a densely inhabited area with some local shadowing. Its performance and its specific yield is comparatively low due to a combination of several reasons (geometry of the concept, inverter, high module temperature, local shadows). The third installation was constructed along the motor way A1 at Bruettisellen in 1999. Its vertical panels are equipped with amorphous modules. The report show, that the performance of the system is reasonable, but the mechanical construction has to be improved. A small trial field with cells directly laminated onto the steel panel, also installed at Bruettisellen, could be the key development for this concept. This final report includes the evaluation and comparison of the monitored data in the past 24 months of operation. (author)

  2. Application of thermal barrier coating for improving the suitability of Annona biodiesel in a diesel engine

    Directory of Open Access Journals (Sweden)

    Ramalingam Senthil

    2016-01-01

    Full Text Available The Annona biodiesel was produced from Annona oil through transesterification process. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using a annona methyl ester as a fuel. They are blended together with the Neat diesel fuel such as 20%, 40%, 60%, 80%, and Neat biodiesel. The performance, emission and combustion characteristics are evaluated by operating the engine at different loads. The performance parameters such as brake thermal efficiency, brake specific fuel consumption. The emission constituents such as carbon monoxide, unburned hydrocarbons, oxides of nitrogen, and smoke were recorded. Then the piston and both exhaust and intake valves of the test engine were coated with 100 µm of NiCrAl as lining layer. Later the same parts were coated with 400 µm material of coating that was the mixture of 88% of ZrO2, 4% of MgO, and 8% of Al2O3. After the engine coating process, the same fuels is tested in the engine at the same engine operation. The same performance and emission parameters were evaluated. Finally, these parameters are compared with uncoated engine in order to find out the changes in the performance and emission parameters of the coated engine. It is concluded that the coating engine resulting in better performance, especially in considerably lower brake specific fuel consumption values. The engine emissions are lowered both through coating and annona methyl ester biodiesel expect the nitrogen oxides emission.

  3. Globalization and Organizational Change: Engineers' Experiences and Their Implications for Engineering Education

    Science.gov (United States)

    Lucena, Juan C.

    2006-01-01

    The demand for flexible engineers presents significant challenges to engineering education. Among these is the need for engineers to be prepared to understand and deal with organizational change. Yet engineering education and research on engineers have overlooked the impact of organizational change on engineering work. After outlining the impact…

  4. The evaluation of the effects of buffer thickness and dry density on radionuclides migration in engineered barrier system

    International Nuclear Information System (INIS)

    Kato, Fujitaka; Ishihara, Yoshinao; Makino, Hitoshi; Ishiguro, Katsuhiko

    2000-01-01

    The evaluation of the effects of buffer thickness and dry density, one of the buffer design, on radionuclides migration behavior is important from the viewpoint of performance assessment since they have relation to radionuclides migration retardation. It is also considered to help investigation of buffer design that satisfy both safety and economy to condition of the disposal site, which may be required with development of disposal project in the future. Therefore we have performed a sensitivity analysis used buffer thickness and dry density as parameter and considered their combination in this report. Based on this, we have evaluated the effects of buffer thickness and dry density on radionuclides migration in engineered barrier system. And, we have considered about radionuclides migration retardation quality of the buffer which is based on the design (relationship between thickness and dry density) set in the second progress report on research and development for the geological disposal of HLW in Japan. In results, the maximum release rates from the engineered barrier system for the nuclides which have high distribution coefficients and short half lives are sensitive to changes in buffer thickness and dry density. And, using dose converted from the nuclide release rates from the engineered barrier system as a convenient index, it is almost shown that the maximum of total dose is less than 10 μ Sv/y in the cases which buffer thickness and dry density are based on the buffer design set in the second progress report on research and development for the geological disposal of HLW in Japan. These can be used as an information when design of buffer thickness and dry density is set by synthetically judgement of balance of safety and economy. (author)

  5. PERFORMANCE ANALYSIS OF 1,4 DIOXANE-ETHANOL-DIESEL BLENDS ON DIESEL ENGINES WITH AND WITHOUT THERMAL BARRIER COATING

    OpenAIRE

    Chockalingam Sundar Raj; Sambandam Arul; Subramanian Sendilvelan; Ganapathy Saravanan

    2010-01-01

    1,4 dioxane, a new additive allows the splash blending of ethanol in diesel in a clear solution. The objective of this investigation is to first create a stable ethanol-diesel blended fuel with 10% 1,4 dioxane additive, and then to generate performance, combustion and emissions data for evaluation of different ethanol content on a single cylinder diesel engine with and without thermal barrier coating. Results show improved performance with blends compared to neat fuel for all conditions of th...

  6. Reference analysis on the use of engineered barriers for isolation of spent nuclear fuel in granite and basalt

    International Nuclear Information System (INIS)

    Cloninger, M.O.; Cole, C.R.

    1981-08-01

    This report evaluates the effectiveness of engineered barriers in delaying or reducing the rate of release of radionuclides from spent fuel in geologic respositories in granite and basalt. It was assumed that the major exposure pathway from the respository to humans would be the ground-water system overlying or underlying a site. Hence, this report focuses on ground-water pathways. A geosphere transport model, GETOUT, and the biosphere transport/dose models, ALLDOS and PABLM, were integrated and used to calculate the potential radiological dose that might be received by humans at various times after repository closure

  7. Implementation of geomechanical models for engineered clay barriers in multi-physic partial differential equation solvers

    International Nuclear Information System (INIS)

    Navarro, V.; Alonso, J.; Asensio, L.; Yustres, A.; Pintado, X.

    2012-01-01

    when using the mixed method. The constitutive formulation is implemented as a balance equation. This way, the user can freely implement models involving implicit relationships between variables. To illustrate the application of this method, we have analysed the implementation of a modified formulation of the Barcelona Expansive Model, a critical state model (CSM) of reference for expansive clays, as it is the case for bentonite clays for engineered barriers for radioactive nuclear spent fuel confinement. The tool developed was used to satisfactorily model the coupled hydro-mechanical problem of the free-swelling of a MX-80 bentonite disc. The bentonite sample had an initial dry density of 1600 kg/m 3 and a water content of 10% in mass. The initial dimensions of the disk were a height of 15.85 mm and a diameter of 100 mm. The hydration with deionised water applied on the top face of the sample was modelled with a saturation boundary condition. Figure 1 illustrates the case modelled and results obtained on pore water pressure and swelling of the sample at an intermediate time in the simulation. In addition, the modelling results have been compared with the experimental results obtained in the laboratory test carried out by B+TECH, as shown in Figure 2. In conclusion, the present proposal means a useful approach for the introduction of advanced Soil Mechanics models to the modelling of bentonite clays in multi-physics partial differential solvers. The use of it enables to overcome the limitations of some MPDES to integrate state functions defined implicitly. This makes it possible to combine the versatility of MPDES with powerful constitutive grounds. (authors)

  8. Malaysian government dentists' experience, willingness and barriers in providing domiciliary care for elderly people.

    Science.gov (United States)

    Othman, Akmal Aida; Yusof, Zamros; Saub, Roslan

    2014-06-01

    To assess Malaysian government dentists' experience, willingness and barriers in providing domiciliary care for elderly people. A descriptive cross-sectional study was conducted using a self-administered postal questionnaire targeting government dentists working in the Ministry of Health in Peninsular Malaysia. Seven hundred and eleven out of 962 dentists responded with a response rate of 74.0%. Only 36.1% of the dentists had experience in providing domiciliary care for elderly people in the past 2 years with mean number of visit per year of 1. Younger dentists below the age of 30 and those with confidence in providing the service were the most willing to undertake domiciliary care for elderly patients (OR=13.5, pworking condition (64.4%). The majority of Malaysian government dentists had not been involved in providing domiciliary care for elderly patients. Apart from overcoming the barriers, other recommendations include improving undergraduate dental education, education for elderly people and carers, improving dentist's working condition, and introducing domiciliary financial incentive for dentist. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  9. Commercially sexually exploited youths' health care experiences, barriers, and recommendations: A qualitative analysis.

    Science.gov (United States)

    Ijadi-Maghsoodi, Roya; Bath, Eraka; Cook, Mekeila; Textor, Lauren; Barnert, Elizabeth

    2018-02-01

    The current study sought to understand commercially sexually exploited (CSE) youths' health care experiences, barriers to care, and recommendations for improving health care services. We conducted focus groups (N=5) with 18 CSE youth from February 2015 through May 2016 at two group homes serving CSE youth in Southern California. We performed thematic content analysis to identify emergent themes about CSE youths' perspectives on health care. Youth described facilitators to care, including availability of services such as screening for sexually transmitted infections, knowledge about sexual health, and a strong motivation to stay healthy. Barriers included feeling judged, concerns about confidentiality, fear, perceived low quality of services, and self-reliance. Overall, youth emphasized self-reliance and "street smarts" for survival and de-emphasized "victimhood," which shaped their interactions with health care, and recommended that health providers develop increased understanding of CSE youth. Our findings suggest that providers and community agencies can play an essential role in raising awareness of the needs of CSE youth and meet their health needs through creating a non-judgmental environment in health care settings that validates the experiences of these youth. Published by Elsevier Ltd.

  10. Some Danish experience with product-service systems and their potentials and barriers to sustainable development

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2003-01-01

    This paper is one of the first attempts to scan the Danish experience with product-service systems and analyse the experiences with respect to potentials and barriers to sustainable development, i.e. reduced resource consumption and reduced environmental impact. The scan shows a variety of product-service-systems......: some have been around for many years and have not be set up for sustainability purposes, while others are rather new and are attempts to contribute to a more sustainable development. Some of the systems identified are so to say born as product-service-systems (like food catering), while others have...... been developed from being a product system into being a product-service-systems in order to support the marketing of more environmental friendly products....

  11. Barriers to Medical Compassion as a Function of Experience and Specialization: Psychiatry, Pediatrics, Internal Medicine, Surgery, and General Practice.

    Science.gov (United States)

    Fernando, Antonio T; Consedine, Nathan S

    2017-06-01

    Compassion is an expectation of patients, regulatory bodies, and physicians themselves. Most research has, however, studied compassion fatigue rather than compassion itself and has concentrated on the role of the physician. The Transactional Model of Physician Compassion suggests that physician, patient, external environment, and clinical factors are all relevant. Because these factors vary both across different specialities and among physicians with differing degrees of experience, barriers to compassion are also likely to vary. We describe barriers to physician compassion as a function of specialization (psychiatry, general practice, surgery, internal medicine, and pediatrics) and physician experience. We used a cross-sectional study using demographic data, specialization, practice parameters, and the Barriers to Physician Compassion Questionnaire. Nonrandom convenience sampling was used to recruit 580 doctors, of whom 444 belonged to the targeted speciality groups. The sample was characterized before conducting a factorial Multivariate Analysis of Covariance and further post hoc analyses. A 5 (speciality grouping) × 2 (more vs. less physician experience) Multivariate Analysis of Covariance showed that the barriers varied as a function of both speciality and experience. In general, psychiatrists reported lower barriers, whereas general practitioners and internal medicine specialists generally reported greater barriers. Barriers were generally greater among less experienced doctors. Documenting and investigating barriers to compassion in different speciality groups have the potential to broaden current foci beyond the physician and inform interventions aimed at enhancing medical compassion. In addition, certain aspects of the training or practice of psychiatry that enhance compassion may mitigate barriers to compassion in other specialities. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

  12. Combined effects of thermal barrier coating and blending with diesel fuel on usability of vegetable oils in diesel engines

    International Nuclear Information System (INIS)

    Aydin, Hüseyin

    2013-01-01

    The possibility of using pure vegetable oils in a thermally insulated diesel engine has been experimentally investigated. Initially, the standard diesel fuel was tested in the engine, as base experiment for comparison. Then the engine was thermally insulated by coating some parts of it, such as piston, exhaust and intake valves surfaces with zirconium oxide (ZrO 2 ). The main purpose of engine coating was to reduce heat rejection from the walls of combustion chamber and to increase thermal efficiency and thus to increase performance of the engine that using vegetable oil blends. Another aim of the study was to improve the usability of pure vegetable oils in diesel engines without performing any fuel treatments such as pyrolysis, emulsification and transesterification. Pure inedible cottonseed oil and sunflower oil were blended with diesel fuel. Blends and diesel fuel were then tested in the coated diesel engine. Experimental results proved that the main purpose of this study was achieved as the engine performance parameters such as power and torque were increased with simultaneous decrease in fuel consumption (bsfc). Furthermore, exhaust emission parameters such as CO, HC, and Smoke opacity were decreased. Also, sunflower oil blends presented better performance and emission parameters than cottonseed oil blends. -- Highlights: ► Usability of two different vegetable oils in a coated diesel engine was experimentally investigated. ► A diesel engine was coated with ZrO 2 layer to make the combustion chamber insulated. ► Test results showed significant improvements in performance parameters. ► While only minor reductions were observed in emissions with coated engine operation

  13. Physicians’ experience adopting the electronic transfer of care communication tool: barriers and opportunities

    Directory of Open Access Journals (Sweden)

    de Grood C

    2015-01-01

    Full Text Available Chloe de Grood, Katherine Eso, Maria Jose Santana Department of Community Health Sciences, W21C Research and Innovation Centre, Institute of Public Health, University of Calgary, Calgary, AB, Canada Purpose: The purpose of this study was to assess physicians' perceptions on a newly developed electronic transfer of care (e-TOC communication tool and identify barriers and opportunities toward its adoption. Participants and methods: The study was conducted in a tertiary care teaching center as part of a randomized controlled trial assessing the efficacy of an e-TOC communication tool. The e-TOC technology was developed through iterative consultation with stakeholders. This e-TOC summary was populated by acute care physicians (AcPs and communicated electronically to community care physicians (CcPs. The AcPs consisted of attending physicians, resident trainees, and medical students rotating through the Medical Teaching Unit. The CcPs were health care providers caring for patients discharged from hospital to the community. AcPs and CcPs completed validated surveys assessing their experience with the newly developed e-TOC tool. Free text questions were added to gather general comments from both groups of physicians. Units of analysis were individual physicians. Data from the surveys were analyzed using mixed methods. Results: AcPs completed 138 linked pre- and post-rotation surveys. At post-rotation, each AcP completed an average of six e-TOC summaries, taking an average of 37 minutes per e-TOC summary. Over 100 CcPs assessed the quality of the TOC summaries, with an overall rating of 8.3 (standard deviation: 1.48; on a scale of 1–10. Thematic analyses revealed barriers and opportunities encountered by physicians toward the adoption of the e-TOC tool. While the AcPs highlighted issues with timeliness, usability, and presentation, the CcPs identified barriers accessing the web-based TOC summaries, emphasizing that the summaries were timely and the

  14. Aboriginal Health Workers experience multilevel barriers to quitting smoking: a qualitative study

    Directory of Open Access Journals (Sweden)

    Dawson Anna P

    2012-05-01

    Full Text Available Abstract Introduction Long-term measures to reduce tobacco consumption in Australia have had differential effects in the population. The prevalence of smoking in Aboriginal peoples is currently more than double that of the non-Aboriginal population. Aboriginal Health Workers are responsible for providing primary health care to Aboriginal clients including smoking cessation programs. However, Aboriginal Health Workers are frequently smokers themselves, and their smoking undermines the smoking cessation services they deliver to Aboriginal clients. An understanding of the barriers to quitting smoking experienced by Aboriginal Health Workers is needed to design culturally relevant smoking cessation programs. Once smoking is reduced in Aboriginal Health Workers, they may then be able to support Aboriginal clients to quit smoking. Methods We undertook a fundamental qualitative description study underpinned by social ecological theory. The research was participatory, and academic researchers worked in partnership with personnel from the local Aboriginal health council. The barriers Aboriginal Health Workers experience in relation to quitting smoking were explored in 34 semi-structured interviews (with 23 Aboriginal Health Workers and 11 other health staff and 3 focus groups (n = 17 participants with key informants. Content analysis was performed on transcribed text and interview notes. Results Aboriginal Health Workers spoke of burdensome stress and grief which made them unable to prioritise quitting smoking. They lacked knowledge about quitting and access to culturally relevant quitting resources. Interpersonal obstacles included a social pressure to smoke, social exclusion when quitting, and few role models. In many workplaces, smoking was part of organisational culture and there were challenges to implementation of Smokefree policy. Respondents identified inadequate funding of tobacco programs and a lack of Smokefree public spaces as policy

  15. Aboriginal health workers experience multilevel barriers to quitting smoking: a qualitative study.

    Science.gov (United States)

    Dawson, Anna P; Cargo, Margaret; Stewart, Harold; Chong, Alwin; Daniel, Mark

    2012-05-23

    Long-term measures to reduce tobacco consumption in Australia have had differential effects in the population. The prevalence of smoking in Aboriginal peoples is currently more than double that of the non-Aboriginal population. Aboriginal Health Workers are responsible for providing primary health care to Aboriginal clients including smoking cessation programs. However, Aboriginal Health Workers are frequently smokers themselves, and their smoking undermines the smoking cessation services they deliver to Aboriginal clients. An understanding of the barriers to quitting smoking experienced by Aboriginal Health Workers is needed to design culturally relevant smoking cessation programs. Once smoking is reduced in Aboriginal Health Workers, they may then be able to support Aboriginal clients to quit smoking. We undertook a fundamental qualitative description study underpinned by social ecological theory. The research was participatory, and academic researchers worked in partnership with personnel from the local Aboriginal health council. The barriers Aboriginal Health Workers experience in relation to quitting smoking were explored in 34 semi-structured interviews (with 23 Aboriginal Health Workers and 11 other health staff) and 3 focus groups (n = 17 participants) with key informants. Content analysis was performed on transcribed text and interview notes. Aboriginal Health Workers spoke of burdensome stress and grief which made them unable to prioritise quitting smoking. They lacked knowledge about quitting and access to culturally relevant quitting resources. Interpersonal obstacles included a social pressure to smoke, social exclusion when quitting, and few role models. In many workplaces, smoking was part of organisational culture and there were challenges to implementation of Smokefree policy. Respondents identified inadequate funding of tobacco programs and a lack of Smokefree public spaces as policy level barriers. The normalisation of smoking in Aboriginal

  16. Optimising child outcomes from parenting interventions: fathers' experiences, preferences and barriers to participation.

    Science.gov (United States)

    Tully, Lucy A; Piotrowska, Patrycja J; Collins, Daniel A J; Mairet, Kathleen S; Black, Nicola; Kimonis, Eva R; Hawes, David J; Moul, Caroline; Lenroot, Rhoshel K; Frick, Paul J; Anderson, Vicki; Dadds, Mark R

    2017-06-07

    Early childhood interventions can have both immediate and long-term positive effects on cognitive, behavioural, health and education outcomes. Fathers are underrepresented in interventions focusing on the well-being of children. However, father participation may be critical for intervention effectiveness, especially for parenting interventions for child externalising problems. To date, there has been very little research conducted to understand the low rates of father participation and to facilitate the development of interventions to meet the needs of fathers. This study examined fathers' experiences of, and preferences for, parenting interventions as well as perceptions of barriers to participation. It also examined how these factors were associated with child externalising behaviour problems, and explored the predictors of participation in parenting interventions. A community sample of 1001 fathers of children aged 2-16 years completed an online survey about experiences with parenting interventions, perceived barriers to participation, the importance of different factors in their decision to attend, and preferred content and delivery methods. They also completed ratings of their child's behaviour using the Strengths and Difficulties Questionnaire. Overall, 15% of fathers had participated in a parenting intervention or treatment for child behaviour, with significantly higher rates of participation for fathers of children with high versus low levels of externalising problems. Fathers rated understanding what is involved in the program and knowing that the facilitator is trained as the two most important factors in their decision to participate. There were several barriers to participation that fathers of children with high-level externalising problems were more likely to endorse, across practical barriers and help-seeking attitudes, compared to fathers of children with low-level externalising problems. Almost two-thirds of fathers of children with high

  17. Optimising child outcomes from parenting interventions: fathers’ experiences, preferences and barriers to participation

    Directory of Open Access Journals (Sweden)

    Lucy A. Tully

    2017-06-01

    Full Text Available Abstract Background Early childhood interventions can have both immediate and long-term positive effects on cognitive, behavioural, health and education outcomes. Fathers are underrepresented in interventions focusing on the well-being of children. However, father participation may be critical for intervention effectiveness, especially for parenting interventions for child externalising problems. To date, there has been very little research conducted to understand the low rates of father participation and to facilitate the development of interventions to meet the needs of fathers. This study examined fathers’ experiences of, and preferences for, parenting interventions as well as perceptions of barriers to participation. It also examined how these factors were associated with child externalising behaviour problems, and explored the predictors of participation in parenting interventions. Methods A community sample of 1001 fathers of children aged 2–16 years completed an online survey about experiences with parenting interventions, perceived barriers to participation, the importance of different factors in their decision to attend, and preferred content and delivery methods. They also completed ratings of their child’s behaviour using the Strengths and Difficulties Questionnaire. Results Overall, 15% of fathers had participated in a parenting intervention or treatment for child behaviour, with significantly higher rates of participation for fathers of children with high versus low levels of externalising problems. Fathers rated understanding what is involved in the program and knowing that the facilitator is trained as the two most important factors in their decision to participate. There were several barriers to participation that fathers of children with high-level externalising problems were more likely to endorse, across practical barriers and help-seeking attitudes, compared to fathers of children with low-level externalising problems

  18. ABB.-Combustion Engineering's Experience in Nuclear Power Plant Engineering and Construction in Korea

    International Nuclear Information System (INIS)

    Veris, James W.

    1992-01-01

    The Yonggwang Nuclear Project is a milestone project for the Korean Nuclear Industry. The Project has the two objectives of obtaining self-reliance in all aspects of nuclear technology and of constructing two modern nuclear power plants under the leadership of Korean companies acting as prime contractors. ABB.-Combustion Engineering 1000 MW System 80+ TM was chosen in 1987 as the NSLS design to meet these two objectives. This paper summarizers the significant experiences and lessons learned through the first four years of the Project as well as identifying implications for such future projects. The unique challenges of the project are identified and an evaluation of the experiences in the technology, self-reliance program and in the design and manufacturing processes will be made

  19. FROM GEOMETRY TO DIAGNOSIS: EXPERIENCES OF GEOMATICS IN STRUCTURAL ENGINEERING

    Directory of Open Access Journals (Sweden)

    B. Riveiro

    2012-07-01

    Full Text Available Terrestrial photogrammetry and laser scanning are technologies that have been successfully used for metric surveying and 3D modelling in many different fields (archaeological and architectural documentation, industrial retrofitting, mining, structural monitoring, road surveying, etc.. In the case of structural applications, these techniques have been successfully applied to 3D modelling and sometimes monitoring; but they have not been sufficiently implemented to date, as routine tools in infrastructure management systems, in terms of automation of data processing and integration in the condition assessment procedures. In this context, this paper presents a series of experiences in the usage of terrestrial photogrammetry and laser scanning in the context of dimensional and structural evaluation of structures. These experiences are particularly focused on historical masonry structures, but modern prestressed concrete bridges are also investigated. The development of methodological procedures for data collection, and data integration in some cases, is tackled for each particular structure (with access limitations, geometrical configuration, range of measurement, etc.. The accurate geometrical information provided by both terrestrial techniques motivates the implementation of such results in the complex, and sometimes slightly approximated, geometric scene that is frequently used in structural analysis. In this sense, quantitative evaluating of the influence of real and accurate geometry in structural analysis results must be carried out. As main result in this paper, a series of experiences based on the usage of photogrammetric and laser scanning to structural engineering are presented.

  20. Gender and Satisfaction with the Cooperative Education Experience in Engineering

    Science.gov (United States)

    Wilkinson, Karen R.; Sullivan, Laura L.

    This study investigated gender differences in job satisfaction following the first term of a cooperative education program in engineering. Using data from a survey of freshmen, this study tested hypotheses about gender differences in the co-op job experience and the correlates of co-op job satisfaction. Gender-based predictive models of job satisfaction are presented. In general, the correlates of co-op job satisfaction are the same as those identified in past studies of job satisfaction. The level of co-op job satisfaction is the same for men and women, even though women do face some disadvantages. Social influences are important to both men and women, but there are gender differences in the specific predictors.

  1. Experiment with expert system guidance of an engineering analysis task

    International Nuclear Information System (INIS)

    Ransom, V.H.; Fink, R.K.; Callow, R.A.

    1986-01-01

    An experiment is being conducted in which expert systems are used to guide the performance of an engineering analysis task. The task chosen for experimentation is the application of a large thermal hydraulic transient simulation computer code. The expectation from this work is that the expert system will result in an improved analytical result with a reduction in the amount of human labor and expertise required. The code associated functions of model formulation, data input, code execution, and analysis of the computed output have all been identified as candidate tasks that could benefit from the use of expert systems. Expert system modules have been built for the model building and data input task. Initial results include the observation that human expectations of an intelligent environment rapidly escalate and structured or stylized tasks that are tolerated in the unaided system are frustrating within the intelligent environment

  2. First Year Experiences in School of Mechanical Engineering Kanazawa University

    Science.gov (United States)

    Kinari, Toshiyasu; Kanjin, Yuichi; Furuhata, Toru; Tada, Yukio

    This paper reports two lectures of the first year experience, ‧Lecture on Life in Campus and Society‧ and ‧Freshman Seminar‧ and discusses their effects. Both lectures have been given freshmen of the school of mechanical engineering, Kanazawa University in H20 spring term. The former lecture is aimed at freshmen to keep on a proper way in both social and college life. It consists of normal class and e-learning system lectures. E-learning system examination requires students to review the whole text book and that seems to have brought better results in the survey. The latter seminar is aimed at freshmen to get active and self-disciplined learning way through their investigation, discussion, presentation, writing work, and so on.

  3. Re-engineering therapeutic antibodies for Alzheimer's disease as blood-brain barrier penetrating bi-specific antibodies.

    Science.gov (United States)

    Pardridge, William M

    2016-12-01

    Therapeutic antibodies are large molecule drugs that do not cross the blood-brain barrier (BBB). Therefore, drug development of therapeutic antibodies for Alzheimer's disease (AD) requires that these molecules be re-engineered to enable BBB delivery. This is possible by joining the therapeutic antibody with a transporter antibody, resulting in the engineering of a BBB-penetrating bispecific antibody (BSA). Areas covered: The manuscript covers transporter antibodies that cross the BBB via receptor-mediated transport systems on the BBB, such as the insulin receptor or transferrin receptor. Furthermore, it highlights therapeutic antibodies for AD that target the Abeta amyloid peptide, beta secretase-1, or the metabotropic glutamate receptor-1. BSAs are comprised of both the transporter antibody and the therapeutic antibody, as well as IgG constant region, which can induce immune tolerance or trigger transport via Fc receptors. Expert opinion: Multiple types of BSA molecular designs have been used to engineer BBB-penetrating BSAs, which differ in valency and spatial orientation of the transporter and therapeutic domains of the BSA. The plasma pharmacokinetics and dosing regimens of BSAs differ from that of conventional therapeutic antibodies. BBB-penetrating BSAs may be engineered in the future as new treatments of AD, as well as other neural disorders.

  4. A phenomenographic study of students' experiences with transition from pre-college engineering programs to first-year engineering

    Science.gov (United States)

    Salzman, Noah

    Recent national dialogues on the importance of preparing more students for careers in Science, Technology, Engineering, and Mathematics has driven the development of formal and informal learning opportunities for children and adolescents to explore engineering. Despite the growth of these programs, relatively little research exists on how participation in these programs affects students who choose to pursue further study in engineering. The present study addressed this gap through an exploration of the different ways that First-Year Engineering students experience the transition from pre-college engineering to undergraduate engineering studies. Given the focus of this research on students' experiences, phenomenography was chosen to explore the phenomenon of transition from pre-college to first-year engineering at a large, public Midwestern university. This facilitated understanding the range of variation in the ways that students experienced this transition. Twenty-two students with different amounts of participation in a variety of different engineering programs were selected to be interviewed using a purposeful maximum variation sampling strategy. The interviews were guided by a semi-structured interview protocol that encouraged the participants to reflect on their pre-college engineering experiences, their experiences in First-Year Engineering, and the transition between the two domains. The interviews were analyzed using phenomenographic methods to develop an outcome space consisting of five qualitatively different but related ways of experiencing the transition from pre-college to First-Year Engineering. These categories of description included Foreclosure, Frustration, Tedium, Connection, and Engaging Others. With the exception of the first category which was characterized by a lack of passion and commitment to engineering, the remaining four categories formed a hierarchical relationship representing increasing integration in First-Year Engineering. The

  5. Interface Engineering of Organic Schottky Barrier Solar Cells and Its Application in Enhancing Performances of Planar Heterojunction Solar Cells

    Science.gov (United States)

    Jin, Fangming; Su, Zisheng; Chu, Bei; Cheng, Pengfei; Wang, Junbo; Zhao, Haifeng; Gao, Yuan; Yan, Xingwu; Li, Wenlian

    2016-05-01

    In this work, we describe the performance of organic Schottky barrier solar cells with the structure of ITO/molybdenum oxide (MoOx)/boron subphthalocyanine chloride (SubPc)/bathophenanthroline (BPhen)/Al. The SubPc-based Schottky barrier solar cells exhibited a short-circuit current density (Jsc) of 2.59 mA/cm2, an open-circuit voltage (Voc) of 1.06 V, and a power conversion efficiency (PCE) of 0.82% under simulated AM1.5 G solar illumination at 100 mW/cm2. Device performance was substantially enhanced by simply inserting thin organic hole transport material into the interface of MoOx and SubPc. The optimized devices realized a 180% increase in PCE of 2.30% and a peak Voc as high as 1.45 V was observed. We found that the improvement is due to the exciton and electron blocking effect of the interlayer and its thickness plays a vital role in balancing charge separation and suppressing quenching effect. Moreover, applying such interface engineering into MoOx/SubPc/C60 based planar heterojunction cells substantially enhanced the PCE of the device by 44%, from 3.48% to 5.03%. Finally, we also investigated the requirements of the interface material for Schottky barrier modification.

  6. Analysis on the use of engineered barriers for geologic isolation of spent fuel in a reference salt site repository

    International Nuclear Information System (INIS)

    Cloninger, M.O.; Cole, C.R.; Washburn, J.F.

    1980-12-01

    A perspective on the potential durability and effectiveness requirements for the waste form, container and other engineered barriers for geologic disposal of spent nuclear fuel has been developed. This perspective is based on calculated potential doses to individuals who may be exposed to radioactivity released from a repository via a groundwater transport pathway. These potential dose commitments were calculated with an integrated geosphere transport and bioshpere transport model. A sensitivity analysis was accomplished by varying four important system parameters, namely the waste radionuclide release rate from the repository, the delay prior to groundwater contact with the waste (leach initiation), aquifer flow velocity and flow path length. The nuclide retarding capacity of the geologic media, a major determinant of the isolation effectiveness, was not varied as a parameter but was held constant for a particular reference site. This analysis is limited to looking only at engineered barriers whose net effect is either to delay groundwater contact with the waste form or to limit the rate of release of radionuclides into the groundwater once contact has occurred. The analysis considers only leach incident scenarios, including a water well intrusion into the groundwater near a repository, but does not consider other human intrusion events or catastrophic events. The analysis has so far been applied to a reference salt site repository system and conclusions are presented.Basically, in nearly all cases, the regional geology is the most effective barrier to release of radionuclides to the biosphere; however, for long-lived isotopes of carbon, technetium and iodine, which were poorly sorbed on the geologic media, the geology is not very effective once a leach incident is initiated

  7. Evaluation of Monolithic Ceramics and Ceramic Thermal Barrier Coatings for Diesel Engine Applications

    National Research Council Canada - National Science Library

    Swab, Jeffrey J

    2001-01-01

    The Metals and Ceramics Research Branch (MCRB) of the Weapons and Materials Research Directorate is providing ceramic material characterization and evaluation to the Tank Automotive Research, Development, and Engineering Center (TARDEC...

  8. The research on teaching reformation of photoelectric information science and engineering specialty experiments

    Science.gov (United States)

    Zhu, Zheng; Yang, Fan; Zhang, Yang; Geng, Tao; Li, Yuxiang

    2017-08-01

    This paper introduced the idea of teaching reformation of photoelectric information science and engineering specialty experiments. The teaching reformation of specialty experiments was analyzed from many aspects, such as construction of specialized laboratory, experimental methods, experiment content, experiment assessing mechanism, and so on. The teaching of specialty experiments was composed of four levels experiments: basic experiments, comprehensive and designing experiments, innovative research experiments and engineering experiments which are aiming at enterprise production. Scientific research achievements and advanced technology on photoelectric technology were brought into the teaching of specialty experiments, which will develop the students' scientific research ability and make them to be the talent suitable for photoelectric industry.

  9. Managing childhood eczema: qualitative study exploring carers' experiences of barriers and facilitators to treatment adherence.

    Science.gov (United States)

    Santer, Miriam; Burgess, Hana; Yardley, Lucy; Ersser, Steven J; Lewis-Jones, Sue; Muller, Ingrid; Hugh, Catherine; Little, Paul

    2013-11-01

    To explore parents and carers' experiences of barriers and facilitators to treatment adherence in childhood eczema Childhood eczema is common and causes significant impact on quality of life for children and their families, particularly due to sleep disturbance and itch. Non-adherence to application of topical treatments is the main cause of treatment failure. Qualitative interview study. Qualitative interviews were carried out with 31 carers from 28 families of children with eczema. Participants were recruited through primary care and included if they had a child aged 5 or less with a diagnosis of eczema. Interviews were carried out between December 2010-May 2011. Data were analysed using a constant comparative approach. Barriers to treatment adherence included carer beliefs around eczema treatment, the time consuming nature of applying topical treatments, and child resistance to treatment. Families employed a range of strategies in an attempt to work around children's resistance to treatment with varying success. Strategies included involving the child in treatment, distracting the child during treatment, or making a game of it, using rewards, applying treatment to a sleeping child or, in a few cases, physically restraining the child. Some carers reduced frequency of applications in an attempt to reduce child resistance. Regular application of topical treatments to children is an onerous task, particularly in families where child resistance develops. Early recognition and discussion of resistance and better awareness of the strategies to overcome this may help carers to respond positively and avoid establishing habitual confrontation. © 2013 Blackwell Publishing Ltd.

  10. Investigating the complementary value of discrete choice experiments for the evaluation of barriers and facilitators in implementation research: A questionnaire survey

    NARCIS (Netherlands)

    D. van Helvoort-Postulart (Debby); T. van der Weijden (Trudy); B.G.C. Dellaert (Benedict); M. de Kok (Mascha); M.F. von Meyenfeldt (Maarten); C.D. Dirksen (Carmen)

    2009-01-01

    textabstractBackground. The potential barriers and facilitators to change should guide the choice of implementation strategy. Implementation researchers believe that existing methods for the evaluation of potential barriers and facilitators are not satisfactory. Discrete choice experiments (DCE) are

  11. Investigating the complementary value of discrete choice experiments for the evaluation of barriers and facilitators in implementation research: a questionnaire survey.

    NARCIS (Netherlands)

    Helvoort-Postulart, D. van; Weijden, G.D.E.M. van der; Dellaert, B.G.; Kok, M. de; Meyenfeldt, M.F. von; Dirksen, C.D.

    2009-01-01

    ABSTRACT: BACKGROUND: The potential barriers and facilitators to change should guide the choice of implementation strategy. Implementation researchers believe that existing methods for the evaluation of potential barriers and facilitators are not satisfactory. Discrete choice experiments (DCE) are

  12. Chemical buffering in natural and engineered barrier systems: Thermodynamic constraints and performance assessment consequences

    International Nuclear Information System (INIS)

    Arthur, R.C.; Wei Zhou

    2000-12-01

    Thermodynamic and kinetic constraints on the chemical buffering properties of natural and engineered-barrier systems are derived in this study from theoretical descriptions, incorporated in the reaction-path model, of reversible and irreversible mass transfer in multicomponent, multiphase systems. The buffering properties of such systems are conditional properties because they refer to a specific aqueous species in a system that is open with respect to a specific reactant. The solution to a mathematical statement of this concept requires evaluation of the dependence of the activity of the buffered species on incremental changes in the overall reaction-progress variable. This dependence can be represented by a truncated Taylor's series expansion, where the values of associated derivatives are calculated using finite-difference techniques and mass-balance, charge-balance and mass-action constraints. Kinetic constraints on buffering behavior can also be described if the relation between reactant flux and reaction rate is well defined. This relation is explicit for the important case of advective groundwater flow and water-rock interaction. We apply the theoretical basis of the chemical buffering concept to processes that could affect the performance of a deep geologic repository for nuclear waste. Specifically, we focus on the likelihood that an inverse relation must exist between the buffer intensity and the migration velocity of reaction fronts in systems involving advective or diffusive mass transport. A quantitative understanding of this relation would provide the basis for evaluating the potential role of chemical buffering in achieving the isolation and retardation functions, of the EBS and geosphere in a KBS-3 repository. Our preliminary evaluation of this role considers the effects of chemical buffering on the propagation velocity of a pH front in both the near- and far field. We use a geochemical modeling technique compatible with the reaction-path model to

  13. Chemical buffering in natural and engineered barrier systems: Thermodynamic constraints and performance assessment consequences

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C.; Wei Zhou [Monitor Scientific, LLC, Denver, CO (United States)

    2000-12-01

    Thermodynamic and kinetic constraints on the chemical buffering properties of natural and engineered-barrier systems are derived in this study from theoretical descriptions, incorporated in the reaction-path model, of reversible and irreversible mass transfer in multicomponent, multiphase systems. The buffering properties of such systems are conditional properties because they refer to a specific aqueous species in a system that is open with respect to a specific reactant. The solution to a mathematical statement of this concept requires evaluation of the dependence of the activity of the buffered species on incremental changes in the overall reaction-progress variable. This dependence can be represented by a truncated Taylor's series expansion, where the values of associated derivatives are calculated using finite-difference techniques and mass-balance, charge-balance and mass-action constraints. Kinetic constraints on buffering behavior can also be described if the relation between reactant flux and reaction rate is well defined. This relation is explicit for the important case of advective groundwater flow and water-rock interaction. We apply the theoretical basis of the chemical buffering concept to processes that could affect the performance of a deep geologic repository for nuclear waste. Specifically, we focus on the likelihood that an inverse relation must exist between the buffer intensity and the migration velocity of reaction fronts in systems involving advective or diffusive mass transport. A quantitative understanding of this relation would provide the basis for evaluating the potential role of chemical buffering in achieving the isolation and retardation functions, of the EBS and geosphere in a KBS-3 repository. Our preliminary evaluation of this role considers the effects of chemical buffering on the propagation velocity of a pH front in both the near- and far field. We use a geochemical modeling technique compatible with the reaction-path model

  14. Engineering of the divertor injection tokamak experiment (DITE)

    International Nuclear Information System (INIS)

    Plummer, K.M.; Bayes, D.V.; Bell, D.; Burt, J.; Galloway, F.; Sanders, B.C.; Skelton, D.E.; Varley, G.L.

    1976-01-01

    The DITE assembly has been constructed to study the effect of powerful neutral injection and the use of magnetic divertors in Tokamak systems. In addition, the plasma is stabilized by a position controlled feed-back vertical field system developed from results on the CLEO experiment, and added to DITE later in the design stage. The machine is designed for an ultimate plasma current of 340 kA, having a minor radius of 23 cm at q = 2, on a major radius of 113 cm. The 28 kG Bphi field, from 16 liquid nitrogen cooled coils has a 2% ripple at the edge of the plasma. The divertor is a ''bundle'' type, the present design of which is limited to operating in a Bphi field of 18 kG. Neutral Injection, initially by two, and ultimately by four injectors, is intended to supply about 1,500 kW of beam power. The engineering is now complete and the machine commissioned; this paper describes the up-to-date design of the machine and includes some of our experiences during design, construction and commissioning

  15. Novel Active Learning Experiences for Students to Identify Barriers to Independent Living for People with Disabilities.

    Science.gov (United States)

    McArthur, Polly; Burch, Lillian; Moore, Katherine; Hodges, Mary Sue

    2016-07-01

    This article describes interactive learning about independent living for people with disabilities and features the partnership of the College of Nursing and a Center for Independent Living (CIL). Using qualitative descriptive approach, students' written reflections were analyzed. Through "Xtreme Challenge," 82 undergraduate nursing students participated in aspects of independent living as well as identifying barriers. Students were engaged and learned to consider the person before the disability. Moreover, students valued the activity leaders' openness, which facilitated understanding the point of view of a person with disability. The value of partnership was evident as it allowed students to participate in active learning, which led to growth in the affective domain. Students became aware of potential education resources through the CIL. This article will guide educators in designing experiences that teach nursing care at the individual, family, and community level for people living with disabilities. © 2015 Association of Rehabilitation Nurses.

  16. Addressing barriers to health: Experiences of breastfeeding mothers after returning to work.

    Science.gov (United States)

    Valizadeh, Sousan; Hosseinzadeh, Mina; Mohammadi, Eesa; Hassankhani, Hadi; M Fooladi, Marjaneh; Schmied, Virginia

    2017-03-01

    Breastfeeding mothers returning to work often feel exhausted as they must feed on demand and attend to family and employment responsibilities, leading to concerns for their personal health. This study was prompted by a desire to understand and identify barriers to mothers' health. We describe the experiences of 12 Iranian breastfeeding and employed mothers through in-depth and semi-structured interviews and thematic analysis. Two main themes emerged: (i) working and mothering alone and (ii) facing concerns about health. The findings highlight the need for a support system for breastfeeding mothers within the family and in the workplace. Family-friendly policies targeting mothers' and employers' views are needed to support working mothers and promote breastfeeding. © 2017 John Wiley & Sons Australia, Ltd.

  17. Borders as barriers to tourism: tourists experiences at the Beitbridge Border Post (Zimbabwean side

    Directory of Open Access Journals (Sweden)

    Getrude Kwanisai

    2014-01-01

    Full Text Available International borders greatly influence tourism development. In 2012 and 2013, a decline in tourists to Zimbabwe from South Africa was partially attributed to tourist border facilitation issues. It is against this background that this study sought to establish the nature of challenges faced by tourists when using the Beitbridge border post (Zimbabwean side. Questionnaire responses were thematically analysed and the study concluded that border administrative management related issues are a major barrier to tourism. Key among the study's recommendations is that the depressed tourists' border experiences obtaining at Beitbridge border post among other constraints have to be addressed as a matter of urgency. This will enhance Zimbabwe's accessibility, tourist satisfaction and the image of the country as a destination. The paper further identifies several destination managerial implications and future research priorities.

  18. Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2010-09-01

    Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an "effective" barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e

  19. Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2010-01-01

    Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an “effective” barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e

  20. Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels: Next Generation Hydroccarbon Biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2008-03-01

    This roadmap to “Next Generation Hydrocarbon Biorefineries” outlines a number of novel process pathways for biofuels production based on sound scientific and engineering proofs of concept demonstrated in laboratories around the world. This report was based on the workshop of the same name held June 25-26, 2007 in Washington, DC.

  1. Women's Leadership in Science, Technology, Engineering and Mathematics: Barriers to Participation

    Science.gov (United States)

    McCullough, Laura

    2011-01-01

    Despite gains overall, women are still under-represented in leadership positions in science, technology, engineering, and mathematics (STEM) fields. Data in the US suggest around one-quarter of deans and department heads are women; in science this drops to nearly 1 in 20. Part of this problem of under-representation stems from the population pool:…

  2. Safety evaluation methodology of engineering barriers at repository for low and intermediate level radioactive waste

    International Nuclear Information System (INIS)

    Zarnic, R.; Bokan Bosiljkov, V.; Giacomelli, M.

    2007-01-01

    Analyses of the roles of cement-based barriers in radioactive waste isolation show that models used to estimate their characteristics during the lifetime of the repository must consider the alteration of material properties with time due to degradation processes. Reinforced concrete barriers at repositories shall be designed in such manner that they fulfil besides isolative capabilities also the required functions of mechanical resistance and stability. Key elements of safety evaluation are mainly the correct selection of materials for mineral composites with cement binder (cements, aggregates, mineral additives and chemical admixtures) and their design, execution of construction works and production of precast concrete containers (continuous casting of concrete - no cold joints, limited number of construction joints, proper placing and consolidation, finishing and curing), strict control of used materials and inspection of works, as well as investigation after the construction (visual inspection, non-destructive testing, monitoring, ageing assessment on test containers). According to the methodology presented in this paper the lifetime of the repository can be estimated and, if shorter than 300 years or shorter than the period resulting from safety analysis, appropriate corrective measures shall be taken. (author)

  3. Identifying barriers to Science, Technology, Society and environment (STSE) educational goals and pedagogy in science education: A case study of UMASS Lowell undergraduate engineering

    Science.gov (United States)

    Phaneuf, Tiffany

    The implementation of sustainable development in higher education is a global trend. Engineers, as gatekeepers of technological innovation, confront increasingly complex world issues ranging from economic and social to political and environmental. Recently, a multitude of government reports have argued that solving such complex problems requires changes in the pedagogy of engineering education, such as that prescribed by the Science, Technology, Society, and education (STS) movement that grew out of the environmental movement in the 70s. In STS students are engaged in the community by understanding that scientific progress is innately a sociopolitical process that involves dimensions of power, wealth and responsibility. United States accreditation criteria now demand "the broad education necessary to understand the impact of engineering solutions in a global, economic, environmental, and societal context" (ABET Engineering Accreditation Commission 2005). With such emphasis on STS education as necessary to address complex world issues, it is vital to assess the barriers in the traditional engineering curriculum that may inhibit the success of such educational reform. This study identifies barriers to STS goals and pedagogy in post secondary science education by using the Francis College of Engineering at UMASS Lowell as a single case study. The study draws on existing literature to develop a theoretical framework for assessing four hypothesized barriers to STS education in undergraduate engineering. Identification of barriers to STS education in engineering generates a critical reflection of post secondary science education and its role in preparing engineers to be active citizens in shaping a rapidly globalizing world. The study offers policy recommendations for enabling post secondary science education to incorporate STS education into its curriculum.

  4. EDF's Engineering Experience and Contribution to the Nuclear Development

    International Nuclear Information System (INIS)

    Salha, Bernard; Fourest, Bernard; Arpino, Jean-Marc

    2002-01-01

    Electricite de France (EDF) is now operating 58 nuclear power units which produce 76% of the electricity generated in France. This EDF's industrial success is the result of its capacity to master and optimize its production tool, from design through operation. EDF's integrated engineering is in the heart of this process of technical expertise and economic optimization. It allows to be in interface between the needs of operators and industrials suppliers, while accumulating a significant feedback of operating experience. The will of achieving the process of frenchifying PWR technology and to implement new industrial innovations have ended up in the new NPP of 100 % french design, the N4 series and its significant innovations. EDF energy policy is to keep the nuclear option open for the future. This strategy results from the need to improve the availability and the life extension of the units in operation and to prepare the replacement of the operating reactors around 2015. This is the objective of the European Pressurized Reactor (EPR), a French-German joint project. EDF is also applying this industrial process in its international projects. For example China, which desires to implement a standardized nuclear program and to move forward the complete autonomy of its nuclear industry, has decided to adopt a similar approach to EDF's one. (authors)

  5. PReSaFe: A model of barriers and facilitators to patients providing feedback on experiences of safety.

    Science.gov (United States)

    De Brún, Aoife; Heavey, Emily; Waring, Justin; Dawson, Pamela; Scott, Jason

    2017-08-01

    The importance of involving patients in reporting on safety is increasingly recognized. Whilst studies have identified barriers to clinician incident reporting, few have explored barriers and facilitators to patient reporting of safety experiences. This paper explores patient perspectives on providing feedback on safety experiences. Patients (n=28) were invited to take part in semi-structured interviews when given a survey about their experiences of safety following hospital discharge. Transcripts were thematically analysed using NVivo10. Patients were recruited from four hospitals in the UK. Three themes were identified as barriers and facilitators to patient involvement in providing feedback on their safety experiences. The first, cognitive-cultural, found that whilst safety was a priority for most, some felt the term was not relevant to them because safety was the "default" position, and/or because safety could not be disentangled from the overall experience of care. The structural-procedural theme indicated that reporting was facilitated when patients saw the process as straightforward, but that disinclination or perceived inability to provide feedback was a barrier. Finally, learning and change illustrated that perception of the impact of feedback could facilitate or inhibit reporting. When collecting patient feedback on experiences of safety, it is important to consider what may help or hinder this process, beyond the process alone. We present a staged model of prerequisite barriers and facilitators and hypothesize that each stage needs to be achieved for patients to provide feedback on safety experiences. Implications for collecting meaningful data on patients' safety experiences are considered. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

  6. Barriers to and Facilitators of Help-Seeking Behavior Among Men Who Experience Sexual Violence.

    Science.gov (United States)

    Donne, Martina Delle; DeLuca, Joseph; Pleskach, Pavel; Bromson, Christopher; Mosley, Marcus P; Perez, Edward T; Mathews, Shibin G; Stephenson, Rob; Frye, Victoria

    2018-03-01

    Research on sexual violence and related support services access has mainly focused on female victims; there is still a remarkable lack of research on men who experience sexual violence. Research demonstrates that people who both self-identify as men and are members of sexual-orientation minority populations are at higher risk of sexual violence. They are also less likely to either report or seek support services related to such experiences. The present study is an exploratory one aimed at filling the gap in the literature and better understanding how men, both straight and gay as well as cisgender and transgender, conceptualize, understand, and seek help related to sexual violence. A sample of 32 men was recruited on-line and participated in either a one-on-one in-depth interview ( N = 19) or one of two focus group discussions ( N = 13). All interviews and groups were audiotaped, professionally transcribed and coded using NVivo 9 qualitative software. The present analysis focused on barriers to and facilitators of support service access. Emergent and cross-cutting themes were identified and presented, with an emphasis on understanding what factors may prevent disclosure of a sexual violence experience and facilitate seeking support services and/or professional help. Through this analysis, the research team aims to add knowledge to inform the development of tools to increase service access and receipt, for use by both researchers and service professionals. Although this study contributes to the understanding of the issue of men's experiences of sexual violence, more research with diverse populations is needed.

  7. Contribution on the study of microbial effects on the leaching of radionuclides embedded in nuclear waste engineered barriers

    International Nuclear Information System (INIS)

    Spor, H.

    1994-05-01

    The aim of this work is to study the different interactions mechanisms between microorganisms and radioelements in conditions similar to those of a radioactive waste disposal site and to determine all the mechanisms due to microbial effects on the leaching of radionuclides embedded in nuclear waste engineered barriers. In this work are presented the different following points: - a bibliographic study on the microorganisms-radioelements interactions; - the conditions of metabolites production during the microbial growth (influence of the nature of the carbonated source, pH effects, aerobiosis conditions...); the mechanisms of a direct effect for determining the importance of the bio-sorption mechanism by microorganisms; the fact that the microbial biomass can strongly interact with actinides, heavy metals and radioelements; the effects of microorganisms on storage materials (cement and clay) containing radioelements (uranium, cesium); the complexation capacities of the organic and mineral acids produced during the microbial growth. (O.M.)

  8. Reported barriers to evaluation in chronic care: experiences in six European countries.

    Science.gov (United States)

    Knai, Cécile; Nolte, Ellen; Brunn, Matthias; Elissen, Arianne; Conklin, Annalijn; Pedersen, Janice Pedersen; Brereton, Laura; Erler, Antje; Frølich, Anne; Flamm, Maria; Fullerton, Birgitte; Jacobsen, Ramune; Krohn, Robert; Saz-Parkinson, Zuleika; Vrijhoef, Bert; Chevreul, Karine; Durand-Zaleski, Isabelle; Farsi, Fadila; Sarría-Santamera, Antonio; Soennichsen, Andreas

    2013-05-01

    The growing movement of innovative approaches to chronic disease management in Europe has not been matched by a corresponding effort to evaluate them. This paper discusses challenges to evaluation of chronic disease management as reported by experts in six European countries. We conducted 42 semi-structured interviews with key informants from Austria, Denmark, France, Germany, The Netherlands and Spain involved in decision-making and implementation of chronic disease management approaches. Interviews were complemented by a survey on approaches to chronic disease management in each country. Finally two project teams (France and the Netherlands) conducted in-depth case studies on various aspects of chronic care evaluation. We identified three common challenges to evaluation of chronic disease management approaches: (1) a lack of evaluation culture and related shortage of capacity; (2) reluctance of payers or providers to engage in evaluation and (3) practical challenges around data and the heterogeity of IT infrastructure. The ability to evaluate chronic disease management interventions is influenced by contextual and cultural factors. This study contributes to our understanding of some of the most common underlying barriers to chronic care evaluation by highlighting the views and experiences of stakeholders and experts in six European countries. Overcoming the cultural, political and structural barriers to evaluation should be driven by payers and providers, for example by building in incentives such as feedback on performance, aligning financial incentives with programme objectives, collectively participating in designing an appropriate framework for evaluation, and making data use and accessibility consistent with data protection policies. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Summary of activities at the Engineered Barriers Test Facility, October 1, 1995 to January 31, 1997, and initial data

    International Nuclear Information System (INIS)

    Porro, I.; Keck, K.N.

    1997-03-01

    Replicates of two engineered barrier designs (a thick soil barrier and a bio/capillary barrier) were constructed in the test plots of the facility. Prior to placement of any soil in the test plots, instruments were calibrated and attached to plot instrument towers, which were then installed in the test plots. Soil from Spreading Area B was installed in the test plots in lifts and compacted. Instruments attached to the instrument tower were placed in shallow trenches dug in the lifts and buried. Each instrument was checked to make sure it functioned prior to installation of the next lift. Soil samples were collected from each lift in one plot during construction for later determination of physical and hydraulic properties. After completion of the test plots, the data acquisition system was finalized, and data collection began. Appropriate instrument calibration equations and equation coefficients are presented, and data reduction techniques are described. Initial data show test plot soils drying throughout the summer and early fall. This corresponds to low rainfall during this period. Infiltration of water into the test plots was first detected around mid-November with several subsequent episodes in December. Infiltration was verified by corresponding measurements from several different instruments ime domain reflectometry (TDR), neutron probe, thermocouple psychrometers, and heat dissipation sensors Tensiometer data does not appear to corroborate data from the other instruments. Test plots were warmer on the side closest to the access trench indicating a temperature effect from the trench. This resulted in greater soil moisture freezing with less and shallower infiltration on the far side of the plots than on the side closest to the trench. At the end of this monitoring period, infiltration in all but two of the test plots has reached the 155-cm depth. Infiltration in test plots B2 and S3 has reached only the 140-cm depth. The monitored infiltration events have not

  10. Analysis and modelling of power modulation experiments in JET plasmas with internal transport barriers

    Energy Technology Data Exchange (ETDEWEB)

    Marinoni, A [Politecnico di Milano, dipartimento di Ingegneria Nucleare, Milano (Italy); Mantica, P [Istituto di Fisica del Plasma, Euratom-ENEA-CNR Association, Milan (Italy); Eester, D Van [LPP-ERM/KMS, Association EURATOM-Belgian State, TEC, B-1000 Brussels (Belgium); Imbeaux, F [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, 13108 Saint Paul lez Durance (France); Mantsinen, M [Helsinki University of Technology, Association Euratom-Tekes, PO Box 2200 (Finland); Hawkes, N [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Joffrin, E [Association EURATOM-CEA, CEA/DSM/DRFC, CEA Cadarache, 13108 Saint Paul lez Durance (France); Kiptily, V [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Pinches, S D [Max Plank Institut fur Plasmaphysik, Euratom Association, Garching (Germany); Salmi, A [Helsinki University of Technology, Association Euratom-Tekes, PO Box 2200 (Finland); Sharapov, S [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Voitsekhovitch, I [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom); Vries, P de [FOM Institut voor Plasmafysica, Association Euratom-FOM, Nieuwegein, The (Netherlands); Zastrow, K D [Euratom-UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon (United Kingdom)

    2006-10-15

    Understanding the physics of internal transport barriers (ITBs) is a crucial issue in developing ITER relevant advanced tokamak scenarios. To gain new information on ITBs, RF power modulation experiments, mainly devoted to the study of electron heat transport through ITBs, have been performed on the JET tokamak. The main physics results have been reported in [1]. The present paper describes in detail the data analysis and numerical modelling work carried out for the interpretation of the experiments. ITBs located in the negative shear region behave as localized insulating layers able to stop the heat wave propagation, thus implying that the ITB is a region of low diffusivity characterized by a loss of stiffness. Various sources of spurious effects affecting the interpretation of the results are analysed and discussed. First principle based models have so far failed to predict the temperature profile in the first place, which prevented their application to modulation results, while empirical transport models have been set up and reproduce the major part of the data.

  11. Low-voltage high-speed programming gate-all-around floating gate memory cell with tunnel barrier engineering

    Science.gov (United States)

    Hamzah, Afiq; Ezaila Alias, N.; Ismail, Razali

    2018-06-01

    The aim of this study is to investigate the memory performances of gate-all-around floating gate (GAA-FG) memory cell implementing engineered tunnel barrier concept of variable oxide thickness (VARIOT) of low-k/high-k for several high-k (i.e., Si3N4, Al2O3, HfO2, and ZrO2) with low-k SiO2 using three-dimensional (3D) simulator Silvaco ATLAS. The simulation work is conducted by initially determining the optimized thickness of low-k/high-k barrier-stacked and extracting their Fowler–Nordheim (FN) coefficients. Based on the optimized parameters the device performances of GAA-FG for fast program operation and data retention are assessed using benchmark set by 6 and 8 nm SiO2 tunnel layer respectively. The programming speed has been improved and wide memory window with 30% increment from conventional SiO2 has been obtained using SiO2/Al2O3 tunnel layer due to its thin low-k dielectric thickness. Furthermore, given its high band edges only 1% of charge-loss is expected after 10 years of ‑3.6/3.6 V gate stress.

  12. Barriers to the Uptake of Concurrent Engineering in the Nigerian Construction Industry

    OpenAIRE

    Aniekwu, Nathaniel Anny; Igboanugo, Anthony C.

    2012-01-01

    It is the consensus of scholars that the productivity of the construction industry is very low when compared with other industries. Concurrent Engineering (CE), which has a primary goal of reducing the total time from designing a product to releasing it into the market, while creating better designs as well, has been identified as one of the concepts that has yielded effective adaptation in the construction industry. An exploratory survey was used to identify 63 variables with the capacity to...

  13. Experience of Developing a Meta-Semantic Search Engine

    OpenAIRE

    Mukhopadhyay, Debajyoti; Sharma, Manoj; Joshi, Gajanan; Pagare, Trupti; Palwe, Adarsha

    2013-01-01

    Thinking of todays web search scenario which is mainly keyword based, leads to the need of effective and meaningful search provided by Semantic Web. Existing search engines are vulnerable to provide relevant answers to users query due to their dependency on simple data available in web pages. On other hand, semantic search engines provide efficient and relevant results as the semantic web manages information with well defined meaning using ontology. A Meta-Search engine is a search tool that ...

  14. War experiences, general functioning and barriers to care among former child soldiers in Northern Uganda: the WAYS study.

    Science.gov (United States)

    Amone-P'Olak, Kennedy; Jones, Peter; Meiser-Stedman, Richard; Abbott, Rosemary; Ayella-Ataro, Paul Stephen; Amone, Jackson; Ovuga, Emilio

    2014-12-01

    Exposure to war is associated with considerable risks for long-term mental health problems (MHP) and poor functioning. Yet little is known about functioning and mental health service (MHS) use among former child soldiers (FCS). We assessed whether different categories of war experiences predict functioning and perceived need for, sources of and barriers to MHS among FCS. Data were drawn from an on-going War-affected Youths (WAYS) cohort study of FCS in Uganda. Participants completed questionnaires about war experiences, functioning and perceived need for, sources of and barriers to MHS. Regression analyses and parametric tests were used to assess between-group differences. Deaths, material losses, threat to loved ones and sexual abuse significantly predicted poor functioning. FCS who received MHS function better than those who did not. Females reported more emotional and behavioural problems and needed MHS more than males. FCS who function poorly indicated more barriers to MHS than those who function well. Stigma, fear of family break-up and lack of health workers were identified as barriers to MHS. Various war experiences affect functioning differently. A significant need for MHS exists amidst barriers to MHS. Nevertheless, FCS are interested in receiving MHS and believe it would benefit them. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Shape Memory Polymers: A Joint Chemical and Materials Engineering Hands-On Experience

    Science.gov (United States)

    Seif, Mujan; Beck, Matthew

    2018-01-01

    Hands-on experiences are excellent tools for increasing retention of first year engineering students. They also encourage interdisciplinary collaboration, a critical skill for modern engineers. In this paper, we describe and evaluate a joint Chemical and Materials Engineering hands-on lab that explores cross-linking and glass transition in…

  16. Field plate engineering for GaN-based Schottky barrier diodes

    International Nuclear Information System (INIS)

    Lei Yong; Shi Hongbiao; Lu Hai; Chen Dunjun; Zhang Rong; Zheng Youdou

    2013-01-01

    The practical design of GaN-based Schottky barrier diodes (SBDs) incorporating a field plate (FP) structure necessitates an understanding of their working mechanism and optimization criteria. In this work, the influences of the parameters of FPs upon breakdown of the diode are investigated in detail and the design rules of FP structures for GaN-based SBDs are presented for a wide scale of material and device parameters. By comparing three representative dielectric materials (SiO 2 , Si 3 N 4 and Al 2 O 3 ) selected for fabricating FPs, it is found that the product of dielectric permittivity and critical field strength of a dielectric material could be used as an index to predict its potential performance for FP applications. (semiconductor devices)

  17. Feasibility of using a high-level waste canister as an engineered barrier in disposal

    International Nuclear Information System (INIS)

    Slate, S.C.; Pitman, S.G.; Nesbitt, J.F.; Partain, W.L.

    1982-08-01

    The objective of this report is to evaluate the feasibility of designing a process canister that could also serve as a barrier canister. To do this a general set of performance criteria is assumed and several metal alloys having a high probability of demonstrating high corrosion resistance under repository conditions are evaluated in a qualitative design assessment. This assessment encompasses canister manufacture, the glass-filling process, interim storage, transportation, and to a limited extent, disposal in a repository. A series of scoping tests were carried out on two titanium alloys and Inconel 625 to determine if the high temperature inherent in the glass-fill processing would seriously affect either the strength or corrosion resistance of these metals. This is a process-related concern unique to the barrier canister concept. The material properties were affected by the heat treatments which simulated both the joule-heated glass melter process (titanium alloys and Inconel 625) and the in-can melter (ICM) process (Inconel 625). However, changes in the material properties were generally within 20% of the original specimens. Accelerated corrosion testing of the heat treated coupons in a highly oxygenated brine showed basic corrosion resistance of titanium grade 12 and Inconel 625 to compare favorably with that of the untreated coupons. The titanium grade 2 coupons experienced severe corrosion pitting. These corrosion tests were of a scoping nature and suitable primarily for the detection of gross sensitivity to the heat treatment inherent in the glass-fill process. They are only suggstive of repository performance since the tests do not adequately model the wide range of repository conditions that could conceivably occur

  18. National Educators' Workshop. Update 92: Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler); Craig, Douglas F. (Compiler)

    1993-01-01

    This document contains a collection of experiments presented and demonstrated at the workshop. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  19. Experiences with Integrating Simulation into a Software Engineering Curriculum

    Science.gov (United States)

    Bollin, Andreas; Hochmuller, Elke; Mittermeir, Roland; Samuelis, Ladislav

    2012-01-01

    Software Engineering education must account for a broad spectrum of knowledge and skills software engineers will be required to apply throughout their professional life. Covering all the topics in depth within a university setting is infeasible due to curricular constraints as well as due to the inherent differences between educational…

  20. 3D engineered models for highway construction : the Iowa experience.

    Science.gov (United States)

    2015-06-01

    3D engineered modeling is a relatively new and developing technology that can provide numerous bene ts to owners, engineers, : contractors, and the general public. This manual is for highway agencies that are considering or are in the process of s...

  1. Experiences on dynamic simulation software in chemical engineering education

    DEFF Research Database (Denmark)

    Komulainen, Tiina M.; Enemark-rasmussen, Rasmus; Sin, Gürkan

    2012-01-01

    Commercial process simulators are increasing interest in the chemical engineer education. In this paper, the use of commercial dynamic simulation software, D-SPICE® and K-Spice®, for three different chemical engineering courses is described and discussed. The courses cover the following topics...

  2. Turkish Students' Career Choices in Engineering: Experiences from Turkey

    Science.gov (United States)

    Cavas, Bulent; Cakiroglu, Jale; Cavas, Pinar; Ertepinar, Hamide

    2011-01-01

    The shortfall of young people, particularly women, in the field of Science, Mathematics and Engineering (SME) has been shown in many national studies. Schreiner and Sjoberg (2007) indicated that boys outnumber girls in physics and engineering studies, while the gender balance is shifted towards the girls in studies including medicine, veterinary…

  3. Experience with performance based training of nuclear criticality safety engineers

    International Nuclear Information System (INIS)

    Taylor, R.G.

    1993-01-01

    For non-reactor nuclear facilities, the U.S. Department of Energy (DOE) does not require that nuclear criticality safety engineers demonstrate qualification for their job. It is likely, however, that more formalism will be required in the future. Current DOE requirements for those positions which do have to demonstrate qualification indicate that qualification should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis is incompletely developed in some areas

  4. Hydraulic interaction of engineered and natural barriers. Task 8b-8d and 8f of SKB

    Energy Technology Data Exchange (ETDEWEB)

    Kroehn, Klaus-Peter

    2017-04-15

    The Task Force on Groundwater Flow and Transport of Solutes (TF GWFTS) and the Task Force on Engineered Barrier Systems (TF EBS) both established by the Svensk Kaernbraenslehantering AB (SKB) have defined the so-called Task 8 to investigate the hydraulic interaction of the granitic host rock at the Hard Rock Laboratory at Aespoeand the bentonite clay buffer in a deep geological repository. Task 8 a-d ran parallel to the related BRIE-project (Bentonite Rock Interaction Experiment) at the AespoeHard Rock Laboratory (HRL). The BRIE-project was concerned with an in-situ test where two boreholes were drilled from a tunnel floor and filled with compacted bentonite. Task 8 encompassed obviously characterizing the groundwater flow field as well as simulating bentonite re-saturation. Described here is an approach to solve the problem by decoupling both aspects. Groundwater flow was simplified to a steady-state single-phase flow model including discretely described large fractures. Modelling was performed with the code d{sup 3}f. Outflow data from the rock was then assigned to the inflow boundary of the alternative re-saturation model realized in the experimental code VIPER. With increasing knowledge about the site the upcoming data and the accompanying flow modelling indicated an inherent problem with predictions for the site and borehole characterization. Specific (deterministic) answers were sought from a flow domain that contains a relevant water-bearing fracture network which is only known in terms of geostatistics. While the overall flow regime could be represented in the final model the results were therefore not detailed below the scale of the boreholes. Early data from the flow model had indicated that water uptake of the bentonite at the bentonite-matrix contact would occur under restricted access to water. This had not been considered in laboratory tests up to then and also not in VIPER. A new appropriate boundary condition was developed and implemented. The time

  5. "It was an education in portion size". Experience of eating a healthy diet and barriers to long term dietary change.

    Science.gov (United States)

    Macdiarmid, J I; Loe, J; Kyle, J; McNeill, G

    2013-12-01

    The aim of the study was to explore the expectations and experience of actually eating a healthy diet and using this experience to identify barriers to healthy eating and sustainable dietary change. Fifty participants (19-63 yrs) were provided with a healthy diet (i.e. complied with dietary recommendations) for three consecutive days. Afterwards a semi-structured interview was carried out to explore expectations, experience and barriers to healthy eating. Using a thematic analysis approach eight dominant themes emerged from the interviews. Four related to expectations and experience of healthy eating; realisation of what are appropriate portion sizes, an expectation to feel hungry, surprise that healthy diets comprised normal food, the desire for sweet snacks (e.g. chocolate). This demonstrated there are some misconception about healthy eating and distorted views of portion size. Four more themes emerged relating to barriers to healthy eating; competing priorities, social, peer and time pressure, importance of value for money, a lack of desire to cook. Poor knowledge of healthy eating or a lack of cooking skills were the least common barrier, suggesting that future interventions and policy to improve dietary intakes need to focus on social, cultural and economic issues rather than on lack of knowledge or skills. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Enhancing the Programming Experience for First-Year Engineering Students through Hands-On Integrated Computer Experiences

    Science.gov (United States)

    Canfield, Stephen L.; Ghafoor, Sheikh; Abdelrahman, Mohamed

    2012-01-01

    This paper describes the redesign and implementation of the course, "Introduction to Programming for Engineers" using microcontroller (MCU) hardware as the programming target. The objective of this effort is to improve the programming competency for engineering students by more closely relating the initial programming experience to the student's…

  7. Full-scale test on coupled thermo-hydro-mechanical processes in engineered barrier system

    International Nuclear Information System (INIS)

    Moro, Yoshiji; Fujita, Tomoo; Kanno, Takeshi; Kobayashi, Akira.

    1994-01-01

    On dynamic behavior within artificial barrier in ground layer disposal of high level radioactive wastes, some phenomena such as exotherm from the wastes, penetration of groundwater from surrounding base rock, swelling pressure formation of buffer material due to penetration of groundwater, ground pressure change of the surrounding base rock, and so forth are supposed to affect each other. It is one of important problems from a viewpoint of elucidation of near field environment in the property evaluation study to evaluate such thermo-hydro-mechanical coupled phenomena. As results of the investigation from such reason and its application to actual test in accompany with execution of heating and water inserting test in the Big-Ben (Big-Bentonite facility), the following informations were obtained: (1) In heating and water inserting test, data on temperature distribution, water content ratio distribution and swelling pressure of each portion for 5 months could be obtained. (2) water migration due to water slope was divided to migrations due to steam and liquid water, of which models were made according to Fick and Darcy laws, respectively. (3) As a simulation of water migration, water diffusion coefficient due to temperature slope could be expressed almost by a model with nonlinearity to temperature. (G.K.)

  8. A qualitative, interprofessional analysis of barriers to and facilitators of implementation of the Department of Veterans Affairs' Clostridium difficile prevention bundle using a human factors engineering approach.

    Science.gov (United States)

    Yanke, Eric; Moriarty, Helene; Carayon, Pascale; Safdar, Nasia

    2018-03-01

    Clostridium difficile infection (CDI) is increasingly prevalent, severe, and costly. Adherence to infection prevention practices remains suboptimal. More effective strategies to implement guidelines and evidence are needed. Interprofessional focus groups consisting of physicians, resident physicians, nurses, and health technicians were conducted for a quality improvement project evaluating adherence to the Department of Veterans Affairs' (VA) nationally mandated C difficile prevention bundle. Qualitative analysis with a visual matrix display identified barrier and facilitator themes guided by the Systems Engineering Initiative for Patient Safety model, a human factors engineering approach. Several themes, encompassing both barriers and facilitators to bundle adherence, emerged. Rapid turnaround time of C difficile polymerase chain reaction testing was a facilitator of timely diagnosis. Too few, poorly located, and cluttered sinks were barriers to appropriate hand hygiene. Patient care workload and the time-consuming process of contact isolation precautions were also barriers to adherence. Multiple work system components serve as barriers to and facilitators of adherence to the VA CDI prevention bundle among an interprofessional group of health care workers. Organizational factors appear to significantly influence bundle adherence. Interprofessional perspectives are needed to identify barriers to and facilitators of bundle implementation, which is a necessary first step to address adherence to bundled infection prevention practices. Published by Elsevier Inc.

  9. Supervisor's experiments on radiation safety trainings in school of engineering

    International Nuclear Information System (INIS)

    Nomura, Kiyoshi

    2005-01-01

    Radiation safety training courses in School of Engineering, The University of Tokyo, were introduced. The number of radiation workers and the usage of radiation and radioisotopes have been surveyed for past 14 years. The number of radiation workers in School of Engineering has increased due to the treatment of X-ray analysis of materials, recently. It is important for workers to understand the present situation of School of Engineering before the treatment of radiation and radioisotopes. What the supervisor should tell to radiation workers were presented herewith. The basic questionnaires after the lecture are effective for radiation safety trainings. (author)

  10. Internal electron transport barrier due to neoclassical ambipolarity in the Helically Symmetric Experiment

    International Nuclear Information System (INIS)

    Lore, J.; Briesemeister, A.; Anderson, D. T.; Anderson, F. S. B.; Likin, K. M.; Talmadge, J. N.; Zhai, K.; Guttenfelder, W.; Deng, C. B.; Spong, D. A.

    2010-01-01

    Electron cyclotron heated plasmas in the Helically Symmetric Experiment (HSX) feature strongly peaked electron temperature profiles; central temperatures are 2.5 keV with 100 kW injected power. These measurements, coupled with neoclassical predictions of large 'electron root' radial electric fields with strong radial shear, are evidence of a neoclassically driven thermal transport barrier. Neoclassical transport quantities are calculated using the PENTA code [D. A. Spong, Phys. Plasmas 12, 056114 (2005)], in which momentum is conserved and parallel flow is included. Unlike a conventional stellarator, which exhibits strong flow damping in all directions on a flux surface, quasisymmetric stellarators are free to rotate in the direction of symmetry, and the effect of momentum conservation in neoclassical calculations may therefore be significant. Momentum conservation is shown to modify the neoclassical ion flux and ambipolar ion root radial electric fields in the quasisymmetric configuration. The effect is much smaller in a HSX configuration where the symmetry is spoiled. In addition to neoclassical transport, a model of trapped electron mode turbulence is used to calculate the turbulent-driven electron thermal diffusivity. Turbulent transport quenching due to the neoclassically predicted radial electric field profile is needed in predictive transport simulations to reproduce the peaking of the measured electron temperature profile [Guttenfelder et al., Phys. Rev. Lett. 101, 215002 (2008)].

  11. Barriers to contraceptive access after health care reform: experiences of young adults in Massachusetts.

    Science.gov (United States)

    Bessett, Danielle; Prager, Joanna; Havard, Julia; Murphy, Danielle J; Agénor, Madina; Foster, Angel M

    2015-01-01

    To explore how Massachusetts' 2006 health insurance reforms affected access to sexual and reproductive health (SRH) services for young adults. We conducted 11 focus group discussions across Massachusetts with 89 women and men aged 18 to 26 in 2009. Most young adults' primary interaction with the health system was for contraceptive and other SRH services, although they knew little about these services. Overall, health insurance literacy was low. Parents were primary decision makers in health insurance choices or assisted their adult children in choosing a plan. Ten percent of our sample was uninsured at the time of the discussion; a lack of knowledge about provisions in Chapter 58 rather than calculated risk analysis characterized periods of uninsurance. The dynamics of being transitionally uninsured, moving between health plans, and moving from a location defined by insurance companies as the coverage area limited consistent access to contraception. Notably, staying on parents' insurance through extended dependency, a provision unique to the post-reform context, had implications for confidentiality and access. Young adults' access to and utilization of contraceptive services in the post-reform period were challenged by unanticipated barriers related to information and privacy. The experience in Massachusetts offers instructive lessons for the implementation of national health care reform. Young adult-targeted efforts should address the challenges of health service utilization unique to this population. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

  12. Barriers and facilitators for vaginal breech births in Australia: Clinician's experiences.

    Science.gov (United States)

    Catling, C; Petrovska, K; Watts, N; Bisits, A; Homer, C S E

    2016-04-01

    Since the Term Breech Trial in 2000, few Australian clinicians have been able to maintain their skills to facilitate vaginal breech births. The overwhelming majority of women with a breech presentation have been given one birth option, that is, caesarean section. The aim of this study was to explore clinician's experiences of caring for women when facilitating a vaginal breech birth. A descriptive exploratory design was undertaken. Nine clinicians (obstetricians and midwives) from two tertiary hospitals in Australia who regularly facilitate vaginal breech birth were interviewed. The interviews were analysed thematically. Participants were five obstetricians and four midwives. There were two overarching themes that arose from the data: Facilitation of and Barriers to vaginal breech birth. A number of sub-themes are described in the paper. In order to facilitate vaginal breech birth and ensure it is given as an option to women, it is necessary to educate, upskill and support colleagues to increase their confidence and abilities, carefully counsel and select suitable women, and approach the option in a calm, collaborative way. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  13. Information barriers and social stratification in higher education: evidence from a field experiment.

    Science.gov (United States)

    Abbiati, Giovanni; Argentin, Gianluca; Barone, Carlo; Schizzerotto, Antonio

    2017-11-29

    Our contribution assesses the role of information barriers for patterns of participation in Higher Education (HE) and the related social inequalities. For this purpose, we developed a large-scale clustered randomised experiment involving over 9,000 high school seniors from 62 Italian schools. We designed a counseling intervention to correct student misperceptions of the profitability of HE, that is, the costs, economic returns and chances of success of investments in different tertiary programs. We employed a longitudinal survey to test whether treated students' educational trajectories evolved differently relative to a control group. We find that, overall, treated students enrolled less often in less remunerative fields of study in favour of postsecondary vocational programmes. Most importantly, this effect varied substantially by parental social class and level of education. The shift towards vocational programmes was mainly due to the offspring of low-educated parents; in contrast, children of tertiary graduates increased their participation in more rewarding university fields. Similarly, the redistribution from weak fields to vocational programmes mainly involved the children of the petty bourgeoisie and the working class, while upper class students invested in more rewarding university fields. We argue that the status-maintenance model proposed by Breen and Goldthorpe can explain these socially differentiated treatment effects. Overall, our results challenge the claim that student misperceptions contribute to horizontal inequalities in access to HE. © London School of Economics and Political Science 2017.

  14. Developing confidence in a coupled TH model based on the results of experiment by using engineering scale test facility, 'COUPLE'

    International Nuclear Information System (INIS)

    Fujisaki, Kiyoshi; Suzuki, Hideaki; Fujita, Tomoo

    2008-03-01

    It is necessary to understand quantitative changes of near-field conditions and processes over time and space for modeling the near-field evolution after emplacement of engineered barriers. However, the coupled phenomena in near-field are complicated because thermo-, hydro-, mechanical, chemical processes will interact each other. The question is, therefore, whether the applied model will represent the coupled behavior adequately or not. In order to develop confidence in the modeling, it is necessary to compare with results of coupled behavior experiments in laboratory or in site. In this report, we evaluated the applicability of a coupled T-H model under the conditions of simulated near-field for the results of coupled T-H experiment in laboratory. As a result, it has been shown that the fitting by the modeling with the measured data is reasonable under this condition. (author)

  15. Interface Schottky barrier engineering via strain in metal-semiconductor composites

    Science.gov (United States)

    Ma, Xiangchao; Dai, Ying; Yu, Lin; Huang, Baibiao

    2016-01-01

    The interfacial carrier transfer property, which is dominated by the interface Schottky barrier height (SBH), plays a crucial role in determining the performance of metal-semiconductor heterostructures in a variety of applications. Therefore, artificially controlling the interface SBH is of great importance for their industrial applications. As a model system, the Au/TiO2 (001) heterostructure is studied using first-principles calculations and the tight-binding method in the present study. Our investigation demonstrates that strain can be an effective way to decrease the interface SBH and that the n-type SBH can be more effectively decreased than the p-type SBH. Astonishingly, strain affects the interface SBH mainly by changing the intrinsic properties of Au and TiO2, whereas the interfacial potential alignment is almost independent of strain due to two opposite effects, which are induced by strain at the interfacial region. These observed trends can be understood on the basis of the general free-electron gas model of typical metals, the tight-binding theory and the crystal-field theory, which suggest that similar trends may be generalized for many other metal-semiconductor heterostructures. Given the commonness and tunability of strain in typical heterostructures, we anticipate that the tunability of the interface SBH with strain described here can provide an alternative effective way for realizing more efficient applications of relevant heterostructures.The interfacial carrier transfer property, which is dominated by the interface Schottky barrier height (SBH), plays a crucial role in determining the performance of metal-semiconductor heterostructures in a variety of applications. Therefore, artificially controlling the interface SBH is of great importance for their industrial applications. As a model system, the Au/TiO2 (001) heterostructure is studied using first-principles calculations and the tight-binding method in the present study. Our investigation

  16. Corrosion of high purity copper as engineering barrier in deep geological repositories

    International Nuclear Information System (INIS)

    Ochoa, Maité; Rodríguez Martín, A.; Farina Silvia, B.

    2013-01-01

    Pure copper with oxygen content below 5 ppm (to minimize segregation at grain boundaries) and doped with phosphorus (to increase creep resistance) is the chosen material for the corrosion-resistant barrier of the High Level Radioactive 2 Wastecontainers in the Swedish and Finnish repository models. These models include the construction of the repository below the water table, which is a reducing environment in which copper has excellent resistance to general and localized corrosion in aqueous electrolytes. The aim of this work is contribute to determine the durability of the material, given that deep geological repositories of HLW are designed to ensure the protection of the environment for periods of hundreds of thousands years. As a first step in a more general analysis the effects of chloride, one of the main aggressive species of corrosion, are evaluated. To this purpose corrosion potential was determined and anodic polarization curves were performed in deaerated solutions varying the chloride concentration between 0.01 and 1M and the temperature between 30 and 90°C. Several electrochemical techniques were used: the evolution of corrosion potential was measured, anodic polarization curves were obtained and electrochemical impedance tests were performed. The analysis was complemented with microscopic observations of the type of corrosive attack, as well as determinations of the eventual corrosion products formed using Energy-Dispersive X-ray Analysis (EDS). Results show that the corrosion potential decreases with the increase of temperature and with the increase of chloride concentration. A correlation of the corrosion potential as a function of temperature and chloride concentration was obtained, with the purpose of making predictions in variable conditions.The current density increases both with temperature and with chloride concentration. A pitting potential is observed in certain conditions. (author)

  17. Extracurricular research activities among senior medical students in Kuwait: experiences, attitudes, and barriers

    Directory of Open Access Journals (Sweden)

    Al-Halabi B

    2014-04-01

    Full Text Available Becher Al-Halabi,1 Yousef Marwan,2 Mohammad Hasan,3 Sulaiman Alkhadhari41Department of Surgery, Mubarak Al-Kabeer Hospital, Ministry of Health, Kuwait; 2Department of Orthopaedic Surgery, Al-Razi Hospital, Al-Sabah Medical Area, Ministry of Health, Kuwait; 3Department of Radiation Oncology, Kuwait Cancer Control Center, Al-Sabah Medical Area, Ministry of Health, Kuwait; 4Department of Psychiatry, Faculty of Medicine, Health Sciences Center, Kuwait University, KuwaitBackground: Research is the foundation of scientific advancement and improvement in quality of health care, which ensures the good health of the community. The aim of this study is to explore experiences, attitudes, and barriers of medical students in Kuwait University (KU in regards to extracurricular research.Methods: A questionnaire about extracurricular research activities (ie, any research activity that is not part of the required undergraduate curriculum, such as publishing a paper, research elective, etc was distributed to 175 senior medical students (years 6 and 7. Descriptive and chi-square analyses were used to analyze the responses, considering a P-value of <0.05 as the cut-off level for significance. The main outcome was defined as taking part in any of the extracurricular research activities.Results: Of the 150 participants (response rate = 85.7%, 26 (17.3%, 68 (45.3%, 52 (34.7%, and 17 (11.3% had published their required medical school research, presented abstracts in conferences, conducted extracurricular research, and completed a research elective/course, respectively; 99 (66.0% took part in any of these activities. Participants who read medical journals regularly (81; 54% reported higher participation in extracurricular research activities than those who did not read journals (P=0.003. Improving the availability of mentors for students' extracurricular research was ranked by the participants as the most important factor to improve their participation in

  18. LEARNING CURVES OF LAPAROSCOPY – BARRIERS TO ADOPTION: A MNJIO EXPERIENCE!

    Directory of Open Access Journals (Sweden)

    Ramesh Maturi

    2016-06-01

    Full Text Available BACKGROUND Laparoscopy has been a new entry in the field of surgery with an active history of around just two decades. Today, it is in a position to challenge the conventional surgery which is in use since ages. It is making rapid inroads into various disciplines of surgery. Rapid improvements in optics, along with improvements in energy devices and mechanical stapling devices gave a fillip to acceptance of laparoscopy by the majority of surgeons. Also accumulating data and evidence has started influencing the sceptical, mobilising them to jump into the bandwagon. Barriers to adoption of new techniques, resistance to learning are common to human nature and it is necessary to have a systematic overview of the issues that might crop, so as to be prepared to overcome the problems of accepting laparoscopy into established centres of surgery. AIMS This publication is a reflection of our experience, our trials and tribulations in taking forward the laparoscopy program at our institution. This publication will give an overview of the steps involved in initiation of laparoscopy and aspires to be a source of answers, for day-to-day issues that crop during the process of learning laparoscopy. METHODS AND MATERIALS Just the way, executing laparoscopic surgery is a team effort, incorporating laparoscopy program in an institution is also a team effort where the members of team extend beyond the operating room. Involvement and co-operation of individuals across departments is a must along with benevolent seniors and a proactive administration. So we collated data by interviewing all the stakeholders of laparoscopy program, analysed observations of the faculty from the operating room and reviewed literature on the world wide web. Opinions of the administrators about their perceptions and the issues faced by the junior staff of the department were taken into consideration. Patients were interviewed before and after laparoscopic surgery. CONCLUSIONS Success at

  19. Malaria programme personnel's experiences, perceived barriers and facilitators to implementing malaria elimination strategy in South Africa.

    Science.gov (United States)

    Hlongwana, Khumbulani Welcome; Sartorius, Benn; Tsoka-Gwegweni, Joyce

    2018-01-10

    South Africa has set an ambitious goal targeting to eliminate malaria by 2018, which is consistent with the United Nations Sustainable Development Goals' call to end the epidemic of malaria by 2030 across the globe. There are conflicting views regarding the feasibility of malaria elimination, and furthermore studies investigating malaria programme personnel's perspectives on strategy implementation are lacking. The study was a cross-sectional survey conducted in 2014 through a face-to-face investigator-administered semi-structured questionnaire to all eligible and consenting malaria programme personnel (team leader to senior manager levels) in three malaria endemic provinces (KwaZulu-Natal, Mpumalanga, and Limpopo) of South Africa. The overall response rate was 88.6% (148/167) among all eligible malaria personnel. The mean age of participants was 47 years (SD 9.7, range 27-70), and the mean work experience of 19.4 years (SD 11.1, range 0-42). The majority were male (78.4%), and 66.9% had secondary level education. Awareness of the malaria elimination policy was high (99.3%), but 89% contended that they were never consulted when the policy was formulated and few had either seen (29.9%) or read (23%) the policy, either in full or in part. Having read the policy was positively associated with professional job designations (managers, EHPs and entomologists) (p = 0.010) and tertiary level education (p = 0.042). There was a sentiment that the policy was neither sufficiently disseminated to all key healthcare workers (76.4%) nor properly adapted (68.9%) for the local operational context in the elimination strategy. Most (89.1%) participants were not optimistic about eliminating malaria by 2018, as they viewed the elimination strategy in South Africa as too theoretical with unrealistic targets. Other identified barriers included inadequate resources (53.5%) and high cross-border movements (19.8%). Most participants were not positive that South Africa could achieve

  20. Alvar engine. An engine with variable compression ratio. Experiments and tests

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Olof

    1998-09-01

    This report is focused on tests with Variable Compression Ratio (VCR) engines, according to the Alvar engine principle. Variable compression ratio means an engine design where it is possible to change the nominal compression ratio. The purpose is to increase the fuel efficiency at part load by increasing the compression ratio. At maximum load, and maybe supercharging with for example turbocharger, it is not possible to keep a high compression ratio because of the knock phenomena. Knock is a shock wave caused by self-ignition of the fuel-air mix. If knock occurs, the engine will be exposed to a destructive load. Because of the reasons mentioned it would be an advantage if it would be possible to change the compression ratio continuously when the load changes. The Alvar engine provides a solution for variable compression ratio based on well-known engine components. This paper provides information about efficiency and emission characteristics from tests with two Alvar engines. Results from tests with a phase shift mechanism (for automatic compression ratio control) for the Alvar engine are also reviewed Examination paper. 5 refs, 23 figs, 2 tabs, 5 appendices

  1. Introducing systems engineering to industrial design engineering students with hands-on experience

    NARCIS (Netherlands)

    Bonnema, Gerrit Maarten; Lutters-Weustink, Ilanit F.; van Houten, Frederikus J.A.M.; Selvaraj, H.; Muthukumar, V.

    2005-01-01

    The article presents an innovative educational project to introduce systems engineering to third year students in industrial design engineering at the University of Twente. In a short period the students are confronted with new technology, namely sensors and actuators. They have to apply this

  2. An Experiment in Integrating an Engineering Communication Toolkit into the Industrial Engineering Curriculum

    Science.gov (United States)

    2011-01-31

    A recent survey on the working habits of professional engineers found that nearly 2/3 of their day is spent communicating with others, while only 1/3 is spent on tasks commonly associated with engineering (Sageev & Romanowski, 2001). Whether it is fa...

  3. Barriers to implementing infection prevention and control guidelines during crises: experiences of health care professionals.

    Science.gov (United States)

    Timen, Aura; Hulscher, Marlies E J L; Rust, Laura; van Steenbergen, Jim E; Akkermans, Reinier P; Grol, Richard P T M; van der Meer, Jos W M

    2010-11-01

    Communicable disease crises can endanger the health care system and often require special guidelines. Understanding reasons for nonadherence to crisis guidelines is needed to improve crisis management. We identified and measured barriers and conditions for optimal adherence as perceived by 4 categories of health care professionals. In-depth interviews were performed (n = 26) to develop a questionnaire for a cross-sectional survey of microbiologists (100% response), infection preventionists (74% response), public health physicians (96% response), and public health nurses (82% response). The groups were asked to appraise barriers encountered during 4 outbreaks (severe acute respiratory syndrome [SARS], Clostridium difficile ribotype 027, rubella, and avian influenza) according to a 5-point Likert scale. When at least 33% of the participants responded "strongly agree," "agree," or "rather agree than disagree," a barrier was defined as "often experienced." The common ("generic") barriers were included in a univariate and multivariate model. Barriers specific to the various groups were studied as well. Crisis guidelines were found to have 4 generic barriers to adherence: (1) lack of imperative or precise wording, (2) lack of easily identifiable instructions specific to each profession, (3) lack of concrete performance targets, and (4) lack of timely and adequate guidance on personal protective equipment and other safety measures. The cross-sectional study also yielded profession-specific sets of often-experienced barriers. To improve adherence to crisis guidelines, the generic barriers should be addressed when developing guidelines, irrespective of the infectious agent. Profession-specific barriers require profession-specific strategies to change attitudes, ensure organizational facilities, and provide an adequate setting for crisis management. Copyright © 2010 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights

  4. Multiple Intimate Partner Violence Experiences: Knowledge, Access, Utilization and Barriers to Utilization of Resources by Women of the African Diaspora.

    Science.gov (United States)

    Sabri, Bushra; Huerta, Julia; Alexander, Kamila A; St Vil, Noelle M; Campbell, Jacquelyn C; Callwood, Gloria B

    2015-11-01

    This study examined knowledge, access, utilization, and barriers to use of resources among Black women exposed to multiple types of intimate partner violence in Baltimore, Maryland and the U.S. Virgin Islands (USVI). We analyzed quantitative survey data collected by 163 women recruited from primary care, prenatal or family planning clinics in Baltimore and the USVI. In addition we analyzed qualitative data from in-depth interviews with 11 women. Quantitative data were analyzed using descriptive statistics and qualitative data were analyzed using thematic analysis. A substantial proportion of Black women with multiple types of violence experiences lacked knowledge of, did not have access to, and did not use resources. Barriers to resource use were identified at the individual, relationship, and community levels. There is need for programs to develop awareness, promote access and utilization of resources, and eliminate barriers to resource use among abused Black women.

  5. Suppressing electron turbulence and triggering internal transport barriers with reversed magnetic shear in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, J. L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Bell, R.; Guttenfelder, W.; Hammett, G. W.; Kaye, S. M.; LeBlanc, B.; Mikkelsen, D. R. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Candy, J. [General Atomics, San Diego, California 92186 (United States); Smith, D. R. [Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. Y. [Nova Photonics Inc., Princeton, New Jersey 08540 (United States)

    2012-05-15

    The National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)] can achieve high electron plasma confinement regimes that are super-critically unstable to the electron temperature gradient driven (ETG) instability. These plasmas, dubbed electron internal transport barriers (e-ITBs), occur when the magnetic shear becomes strongly negative. Using the gyrokinetic code GYRO [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], the first nonlinear ETG simulations of NSTX e-ITB plasmas reinforce this observation. Local simulations identify a strongly upshifted nonlinear critical gradient for thermal transport that depends on magnetic shear. Global simulations show e-ITB formation can occur when the magnetic shear becomes strongly negative. While the ETG-driven thermal flux at the outer edge of the barrier is large enough to be experimentally relevant, the turbulence cannot propagate past the barrier into the plasma interior.

  6. Software Engineering Researchers' Attitudes on Case Studies and Experiments: an Exploratory Survey

    OpenAIRE

    Tofan, Dan; Galster, Matthias; Avgeriou, Paris; Weyns, Danny

    2011-01-01

    Background: Case studies and experiments are research methods frequently applied in empirical software engineering. Experiments are well-­understood and their value as an empirical method is recognized. On the other hand, there seem to be different opinions on what constitutes a case study, and about the value of case studies as a thorough research method. Aim: We aim at exploring the attitudes of software engineering researchers on case studies and experiments. Furthermore, we investigate ho...

  7. Modeling of irradiated graphite {sup 14}C transfer through engineered barriers of a generic geological repository in crystalline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Poskas, Povilas; Grigaliuniene, Dalia, E-mail: Dalia.Grigaliuniene@lei.lt; Narkuniene, Asta; Kilda, Raimondas; Justinavicius, Darius

    2016-11-01

    There are two RBMK-1500 type graphite moderated reactors at the Ignalina nuclear power plant in Lithuania, and they are under decommissioning now. The graphite cannot be disposed of in a near surface repository, because of large amounts of {sup 14}C. Therefore, disposal of the graphite in a geological repository is a reasonable solution. This study presents evaluation of the {sup 14}C transfer by the groundwater pathway into the geosphere from the irradiated graphite in a generic geological repository in crystalline rocks and demonstration of the role of the different components of the engineered barrier system by performing local sensitivity analysis. The speciation of the released {sup 14}C into organic and inorganic compounds as well as the most recent information on {sup 14}C source term was taken into account. Two alternatives were considered in the analysis: disposal of graphite in containers with encapsulant and without it. It was evaluated that the maximal fractional flux of inorganic {sup 14}C into the geosphere can vary from 10{sup −} {sup 11} y{sup −} {sup 1} (for non-encapsulated graphite) to 10{sup −} {sup 12} y{sup −} {sup 1} (for encapsulated graphite) while of organic {sup 14}C it was about 10{sup −} {sup 3} y{sup −} {sup 1} of its inventory. Such difference demonstrates that investigations on the {sup 14}C inventory and chemical form in which it is released are especially important. The parameter with the highest influence on the maximal flux into the geosphere for inorganic {sup 14}C transfer was the sorption coefficient in the backfill and for organic {sup 14}C transfer – the backfill hydraulic conductivity. - Highlights: • Graphite moderated nuclear reactors are being decommissioned. • We studied interaction of disposed material with surrounding environment. • Specifically {sup 14}C transfer through engineered barriers of a geological repository. • Organic {sup 14}C flux to geosphere is considerably higher than inorganic

  8. Permeable Barrier Materials for Strontium Immobilization: - UFA Determination of Hydraulic Conductivity. - Column Sorption Experiments

    National Research Council Canada - National Science Library

    Moody, T

    1996-01-01

    Selected materials were tested to emulate a permeable barrier and to examine the: (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium in Hanford groundwater...

  9. Female peer mentors early in college increase women's positive academic experiences and retention in engineering.

    Science.gov (United States)

    Dennehy, Tara C; Dasgupta, Nilanjana

    2017-06-06

    Scientific and engineering innovation is vital for American competitiveness, quality of life, and national security. However, too few American students, especially women, pursue these fields. Although this problem has attracted enormous attention, rigorously tested interventions outside artificial laboratory settings are quite rare. To address this gap, we conducted a longitudinal field experiment investigating the effect of peer mentoring on women's experiences and retention in engineering during college transition, assessing its impact for 1 y while mentoring was active, and an additional 1 y after mentoring had ended. Incoming women engineering students ( n = 150) were randomly assigned to female or male peer mentors or no mentors for 1 y. Their experiences were assessed multiple times during the intervention year and 1-y postintervention. Female (but not male) mentors protected women's belonging in engineering, self-efficacy, motivation, retention in engineering majors, and postcollege engineering aspirations. Counter to common assumptions, better engineering grades were not associated with more retention or career aspirations in engineering in the first year of college. Notably, increased belonging and self-efficacy were significantly associated with more retention and career aspirations. The benefits of peer mentoring endured long after the intervention had ended, inoculating women for the first 2 y of college-the window of greatest attrition from science, technology, engineering, and mathematics (STEM) majors. Thus, same-gender peer mentoring for a short period during developmental transition points promotes women's success and retention in engineering, yielding dividends over time.

  10. Examining barrier distributions and, in extension, energy derivative of probabilities for surrogate experiments

    International Nuclear Information System (INIS)

    Romain, P.; Duarte, H.; Morillon, B.

    2012-01-01

    The energy derivatives of probabilities are functions suited to a best understanding of certain mechanisms. Applied to compound nuclear reactions, they can bring information on fusion barrier distributions as originally introduced, and also, as presented here, on fission barrier distributions and heights. Extendedly, they permit to access the compound nucleus spin-parity states preferentially populated according to an entrance channel, at a given energy. (authors)

  11. Simulation of the long term alteration of clay minerals in engineered bentonite barriers: nucleation and growth of secondary clay particles

    International Nuclear Information System (INIS)

    Fritz, B.; Clement, A.; Zwingmann, H.; Noguera, C.

    2010-01-01

    Document available in extended abstract form only. The long term stability of clay rich rocks used as barriers to the migration of radionuclides in the environment of nuclear wastes has been intensively studied, looking at the geochemical interactions between clay minerals and aqueous solutions. These studies combine experimental approaches for the short term and numerical modellings for the long term extrapolations, in the frame of the research supported by ANDRA in the French design for High Level Waste (HLW) repository. The main objective of the geochemical numerical tools devoted to clay-solutions interaction processes was to predict the feed-back effects of mineralogical and chemical transformations of clay mineral, in repository conditions as defined by Andra, on their physical and transport properties (porosity, molecular diffusion, permeability). The 1D transport-reaction coupled simulation was done using the code KIRMAT, at 100 deg. C for 100000 years. The fluid considered is that of the Callovo-Oxfordian geological formation (COX) and assumed to diffuse into the clay barrier from one side. On the other side, ferrous iron, is provided by the steel overpack corrosion. Under these conditions, montmorillonite of the clay barrier is only partially transformed into illite, chlorite, and saponite. The simulation shows that only outer parts of the clay barrier is significantly modified, mainly at the interface with the geological environment. These modifications correspond to a closure of the porosity, followed by a decrease of mass transport by molecular diffusion. Near the COX, the swelling pressure of the clays from the barrier is predicted to decrease, but in its major part, the engineered barrier seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure). In this modelling approach, the very important role of secondary clay minerals has to be taken into account with relevant kinetic rate laws; particularly

  12. Results from transient transport experiments in Rijnhuizen tokamak project: Heat convection, transport barriers and 'non-local' effects

    International Nuclear Information System (INIS)

    Mantica, P.; Gorini, G.; Hogeweij, G.M.D.; Kloe, J. de; Lopez Cardozo, N.J.; Schilham, A.M.R.

    2001-01-01

    An overview of experimental transport studies performed on the Rijnhuizen Tokamak Project (RTP) using transient transport techniques in both Ohmic and ECH dominated plasmas is presented. Modulated Electron Cyclotron Heating (ECH) and oblique pellet injection (OPI) have been used to induce electron temperature (T e ) perturbations at different radial locations. These were used to probe the electron transport barriers observed near low order rational magnetic surfaces in ECH dominated steady-state RTP plasmas. Layers of inward electron heat convection in off-axis ECH plasmas were detected with modulated ECH. This suggests that RTP electron transport barriers consist of heat pinch layers rather than layers of low thermal diffusivity. In a different set of experiments, OPI triggered a transient rise of the core T e due to an increase of the T e gradient in the 1< q<2 region. These transient transport barriers were probed with modulated ECH and found to be due to a transient drop of the electron heat diffusivity, except for off-axis ECH plasmas, where a transient inward pinch is also observed. Transient transport studies in RTP could not solve this puzzling interplay between heat diffusion and convection in determining an electron transport barrier. They nevertheless provided challenging experimental evidence both for theoretical modelling and for future experiments. (author)

  13. MANAGING CONFLICT IN ENGINEERING PROJECTS: NEW ZEALAND EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Nicola Naismith

    2016-07-01

    Full Text Available There is a wealth of knowledge concerning conflict management and its resolution in the workplace, however there is a dearth of information relating to conflict management and its resolution in engineering project management. This paper set out to examine the reality of conflict management in engineering project management in New Zealand. This was achieved through a review of credible literature sources and the completion of a pilot study to gain subject matter expert perspectives. The research suggests that conflicts can be destructive, resulting in anxiety and strong emotional responses leading to reflexive reactions including avoidance, aggression, fight, hostility and a breakdown in communications and relationships. Findings indicate that managing a project structure is synonymous with handling conflict and these disagreements can be detrimental to the success of a project. The initial results suggest that a number of factors act as drivers of conflict in engineering projects in New Zealand. These drivers are: power, personality, group dynamics and organisation culture. The conflict resolution tools cited as being widely used for engineering projects are collaboration and negotiation. The paper also offers recommendations for future research.

  14. Cell Formation in Industrial Engineering : Theory, Algorithms and Experiments

    NARCIS (Netherlands)

    Goldengorin, B.; Krushynskyi, D.; Pardalos, P.M.

    2013-01-01

    This book focuses on a development of optimal, flexible, and efficient models and algorithms for cell formation in group technology. Its main aim is to provide a reliable tool that can be used by managers and engineers to design manufacturing cells based on their own preferences and constraints

  15. Recent Efforts and Experiments in the Construction of Aviation Engines

    Science.gov (United States)

    SCHWAGER

    1920-01-01

    It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use. Discussed here are specific efforts to increase flying efficiency, such as reduction of the number of revolutions of the propeller from 1400 to about 900 r.p.m. through the use of a reduction gear, increasing piston velocity, locating two crankshafts in one gear box, and using the two-cycle stroke. Also discussed are improvements in the transformation of fuel energy into engine power, the raising of compression ratios, the use of super-compression with carburetors constructed for high altitudes, the use of turbo-compressors, rotary engines, and the use of variable pitch propellers.

  16. Contracting for engineering services: Experience with innovative fee arrangements

    International Nuclear Information System (INIS)

    Criner, D.E.; Schenk, J.L.

    1995-01-01

    The relationship between an engineering firm and a client can be favorably influenced by a clearly defined incentive plan. This paper addresses several approaches and the advantages and disadvantages of each. It also summarizes the lessons learned to date in using incentive fee arrangements

  17. ATS-6 engineering performance report. Volume 4: Television experiments

    Science.gov (United States)

    Wales, R. O. (Editor)

    1981-01-01

    Experiments sponsored by the US Department of Health Education and Welfare are discussed, including telecommunications, Alaskan health service, Appalachian education satellite project, and the University of the West Indies. The Satellite Instructional Television Experiment in India is reviewed. Independent television experiments are addressed, including AIDSAT and Project Look Up.

  18. First-Hand Experience with Engineering Design and Career Interest in Engineering: An Informal STEM Education Case Study

    Science.gov (United States)

    Ayar, Mehmet C.

    2015-01-01

    The purpose of this study is to present students' experiences, interest in engineering, and personal narratives while participating in a robotics summer camp in a metropolitan city in Turkey. In this study, I used qualitative data collection methods such as interviews, field notes, and observations. I used the four principles of Engle and Conant…

  19. Software engineering knowledge at your fingertips: Experiences with a software engineering-portal

    OpenAIRE

    Punter, T.; Kalmar, R.

    2003-01-01

    In order to keep up the pace with technology development, knowledge on Software Engineering (SE) methods, techniques, and tools is required. For an effective and efficient knowledge transfer, especially Small and Medium-sized Enterprises (SMEs) might benefit from Software Engineering Portals (SE-Portals). This paper provides an analysis of SE-Portals by distinguishing two types: 1) the Knowledge Portal and 2) the Knowledge & Community Portal. On behalf of the analysis we conclude that most SE...

  20. Intended long term performances of cementitious engineered barriers for future storage and disposal facilities for radioactive wastes in Romania

    Directory of Open Access Journals (Sweden)

    Sociu F.

    2013-07-01

    Full Text Available Considering the EU statements, Romania is engaged to endorse in the near future the IAEA relevant publications on geological repository (CNCANa, to update the Medium and Long Term National Strategy for Safe Management of Radioactive Waste and to approve the Road Map for Geological Repository Development. Currently, for example, spent fuel is wet stored for 6 years and after this period it is transported to dry storage in MACSTOR-200 (a concrete monolithic module where it is intended to remain at least 50 years. The present situation for radioactive waste management in Romania is reviewed in the present paper. Focus will be done on existent disposal facilities but, also, on future facilities planned for storage / disposal of radioactive wastes. Considering specific data for Romanian radioactive waste inventory, authors are reviewing the advance in the radioactive waste management in Romania considering its particularities. The team tries to highlight the expected limitations and unknown data related with cementitious engineered barriers that has to be faced in the near future incase of interim storage or for the upcoming long periods of disposal.

  1. A consistent approach for the development of a comprehensive data base of time-dependent parameters for concrete engineered barriers

    Energy Technology Data Exchange (ETDEWEB)

    Seetharam, Suresh C; Perko, Janez; Jacques, Diederik [Belgian Nuclear Research Centre SCK-CEN, Mol (Belgium); Mallants, Dirk [CSIRO Land and Water, Urrbrae (Australia)

    2013-07-01

    This paper presents a consistent approach for the development of a comprehensive data base of time-dependent hydraulic and transport parameters for concrete engineered barriers of the future Dessel near surface repository for low level waste. The parameter derivation is based on integration of selected data obtained through an extensive literature review, data from experimental studies on cementitious materials specific for the Dessel repository and numerical modelling using physically-based models of water and mass transport. Best estimate parameter values for assessment calculations are derived, together with source and expert range and their probability density function wherever the data was sufficient. We further discuss a numerical method for up-scaling laboratory derived parameter values to the repository scale; the resulting large-scale effective parameters are commensurate with numerical grids used in models for radionuclide migration. To accommodate different levels of conservatism in the various assessment calculations defined by ONDRAF/NIRAS, several sets of parameter values have been derived based on assumptions that introduce different degrees of conservatism. For pertinent parameters, the time evolution of such properties due to the long-term concrete degradation is also addressed. The implementation of the consistent approach is demonstrated by considering the pore water diffusion coefficient as an example. (authors)

  2. Influence of Cracks in Cementitious Engineered Barriers in a Near-Surface Disposal System: Assessment Analysis of the Belgian Case

    International Nuclear Information System (INIS)

    Perko, Janez; Seetharam, Suresh C.; Jacques, Diederik; Mallants, Dirk; Cool, Wim; Vermarien, Elise

    2013-01-01

    In large cement-based structures such as a near surface disposal facility for radioactive waste voids and cracks are inevitable. However, the pattern and nature of cracks are very difficult to predict reliably. Cracks facilitate preferential water flow through the facility because their saturated hydraulic conductivity is generally higher than the conductivity of the cementitious matrix. Moreover, sorption within the crack is expected to be lower than in the matrix and hence cracks in engineered barriers can act as a bypass for radionuclides. Consequently, understanding the effects of crack characteristics on contaminant fluxes from the facility is of utmost importance in a safety assessment. In this paper we numerically studied radionuclide leaching from a crack-containing cementitious containment system. First, the effect of cracks on radionuclide fluxes is assessed for a single repository component which contains a radionuclide source (i.e. conditioned radwaste). These analyses reveal the influence of cracks on radionuclide release from the source. The second set of calculations deals with the safety assessment results for the planned near-surface disposal facility for low-level radioactive waste in Dessel (Belgium); our focus is on the analysis of total system behaviour in regards to release of radionuclide fluxes from the facility. Simulation results are interpreted through a complementary safety indicator (radiotoxicity flux). We discuss the possible consequences from different scenarios of cracks and voids. (authors)

  3. Corrosion of similar and dissimilar metal crevices in the engineered barrier system of a potential nuclear waste repository

    International Nuclear Information System (INIS)

    He, X.; Dunn, D.S.; Csontos, A.A.

    2007-01-01

    Crevice corrosion is considered possible if the corrosion potential (E corr ) exceeds the repassivation potential for crevice corrosion (E rcrev ). In this study, potentiodynamic polarization and potentiostatic hold were used to determine the E rcrev of similar and dissimilar metal crevices in the engineered barrier system of the potential Yucca Mountain repository in 0.5 M NaCl, 4 M NaCl, and 4 M MgCl 2 solutions at 95 deg. C. The results were compared with data previously obtained using crevices formed between Alloy 22 and polytetrafluoroethylene. It was observed that, except for Type 316L stainless steel, all other metal-to-metal crevices were less susceptible to crevice corrosion than the corresponding metal-to-polytetrafluoroethylene crevices. Measurements of galvanic coupling were used to evaluate the crevice corrosion propagation behavior in 5 M NaCl solution at 95 deg. C. The crevice specimens were coupled to either an Alloy 22 or a Titanium Grade 7 plate using metal or polytetrafluoroethylene crevice washers. Crevice corrosion of Type 316L stainless steel propagated without repassivation. For all the tests using a polytetrafluoroethylene crevice washer, crevice corrosion of Alloy 22 was initiated at open circuit potential by the addition of CuCl 2 as an oxidant, whereas no crevice corrosion of Alloy 22 was initiated for all the tests using Alloy 22 or Titanium Grade 7 metals as crevice washer. However, crevice corrosion propagation was found to be very limited under such test conditions

  4. Study on mechanical stability of engineered barrier system for deep geological isolation of high-level radioactive waste

    International Nuclear Information System (INIS)

    Saotome, A.; Hara, K.; Fujita, T.; Sasaki, N.

    1991-01-01

    The evaluation of mechanical and hydraulic behavior of buffer material of engineered barrier system under water uptake was carried out by applying swelling-elasto-plastic model to the buffer material, of which swelling pressure was described by swelling coefficient. The result is that displacement of overpack and deformation of buffer material are negligibly small. The analysis on overpack sinking behavior within buffer material was carried out as the creep deformation of the buffer material. The analysis shows that creep sinking of overpack within buffer material is negligibly small if the density of buffer material is taken to some extent. The effects of dilatation of corrosion products by hydrogen-generating corrosion of carbon steel overpack was studied, because the dilatation is not negligible in a long-term period of time. As the results of elasto-plastic analysis, stress generated by the dilatation is absorbed within buffer material and dose not affect the host rock if the buffer material is packed to some extent in thickness. It is important to assess the migration of hydrogen within the buffer material. Based on the results of thermal calculations in the near-field maximum temperature acceptable to the buffer material can be controlled by the spacing of the waste package. The temperature in the near-field in case of avoiding the illitization of the buffer material is not so high as to affect the waste glass and the host rock. (author)

  5. Nuclear engineering experiments at experimental facilities of JNC in graduate course of Tokyo Institute of Technology

    International Nuclear Information System (INIS)

    Hayashizaki, Noriyosu; Takahashi, Minoru; Aoyama, Takafumi; Onose, Shoji

    2005-01-01

    Nuclear engineering experiments using outside facilities of the campus have been offered for graduate students in the nuclear engineering course in Tokyo Institute of Technology (Tokyo Tech.). The experiments are managed with the collaboration of Japan Nuclear Cycle Development Institute (JNC), Japan Atomic Energy Research Institute (JAERI) and Research Reactor Institute, Kyoto University (KUR). This report presents the new curriculum of the nuclear engineering experiments at JNC since 2002. The change is due to the shutdown of Deuterium Criticality Assembly Facility (DCA) that was used as an experimental facility until 2001. Reactor physics experiment using the training simulator of the experimental fast reactor JOYO is continued from the previous curriculum with the addition of the criticality approach experiment and control rods calibration. A new experimental subject is an irradiated material experiment at the Material Monitoring Facility (MMF). As a result, both are acceptable as the student experiments on the fast reactor. (author)

  6. Gaming, texting, learning? Teaching engineering ethics through students' lived experiences with technology.

    Science.gov (United States)

    Voss, Georgina

    2013-09-01

    This paper examines how young peoples' lived experiences with personal technologies can be used to teach engineering ethics in a way which facilitates greater engagement with the subject. Engineering ethics can be challenging to teach: as a form of practical ethics, it is framed around future workplace experience in a professional setting which students are assumed to have no prior experience of. Yet the current generations of engineering students, who have been described as 'digital natives', do however have immersive personal experience with digital technologies; and experiential learning theory describes how students learn ethics more successfully when they can draw on personal experience which give context and meaning to abstract theories. This paper reviews current teaching practices in engineering ethics; and examines young people's engagement with technologies including cell phones, social networking sites, digital music and computer games to identify social and ethical elements of these practices which have relevance for the engineering ethics curricula. From this analysis three case studies are developed to illustrate how facets of the use of these technologies can be drawn on to teach topics including group work and communication; risk and safety; and engineering as social experimentation. Means for bridging personal experience and professional ethics when teaching these cases are discussed. The paper contributes to research and curriculum development in engineering ethics education, and to wider education research about methods of teaching 'the net generation'.

  7. Quality of Design, Analysis and Reporting of Software Engineering Experiments:A Systematic Review

    OpenAIRE

    By Kampenes, Vigdis

    2007-01-01

    Background: Like any research discipline, software engineering research must be of a certain quality to be valuable. High quality research in software engineering ensures that knowledge is accumulated and helpful advice is given to the industry. One way of assessing research quality is to conduct systematic reviews of the published research literature. Objective: The purpose of this work was to assess the quality of published experiments in software engineering with respect to the validit...

  8. International Co-Operation in Control Engineering Education Using Online Experiments

    Science.gov (United States)

    Henry, Jim; Schaedel, Herbert M.

    2005-01-01

    This paper describes the international co-operation experience in teaching control engineering with laboratories being conducted remotely by students via the Internet. This paper describes how the students ran the experiments and their personal experiences with the laboratory. A tool for process identification and controller tuning based on…

  9. Two Brief Interventions to Mitigate a "Chilly Climate" Transform Women's Experience, Relationships, and Achievement in Engineering

    Science.gov (United States)

    Walton, Gregory M.; Logel, Christine; Peach, Jennifer M.; Spencer, Steven J.; Zanna, Mark P.

    2015-01-01

    In a randomized-controlled trial, we tested 2 brief interventions designed to mitigate the effects of a "chilly climate" women may experience in engineering, especially in male-dominated fields. Participants were students entering a selective university engineering program. The "social-belonging intervention" aimed to protect…

  10. Understanding the Experience of Women in Undergraduate Engineering Programs at Public Universities

    Science.gov (United States)

    Perez, Jessica Ohanian

    2017-01-01

    Women earn bachelor's degrees in engineering at a rate of less than 17% at public universities in California. The purpose of this study was to understand how women experience undergraduate engineering programs at public universities. To understand this lack of attainment, a qualitative methodology and Feminist Poststructuralist perspective were…

  11. U.S. Adults with Agricultural Experience Report More Genetic Engineering Familiarity than Those Without

    Science.gov (United States)

    Stofer, Kathryn A.; Schiebel, Tracee M.

    2017-01-01

    Researchers and pollsters still debate the acceptance of genetic engineering technology among U.S. adults, and continue to assess their knowledge as part of this research. While decision-making may not rely entirely on knowledge, querying opinions and perceptions rely on public understanding of genetic engineering terms. Experience with…

  12. Foreign Experience in Training Future Engineering Educators for Modeling Technological Processes

    Science.gov (United States)

    Bokhonko, Yevhen

    2017-01-01

    The article deals with the study of foreign experience in training engineering educators for modeling technological processes. It has been stated that engineering education is a field that is being dramatically developed taking into account the occurring changes in educational paradigms, global higher education space, national higher education…

  13. Moral Responsibility, Technology and Experiences of the Tragic: From Kierkegaard to Offshore Engineering.

    NARCIS (Netherlands)

    Coeckelbergh, Mark

    2010-01-01

    The standard response to engineering disasters like the Deepwater Horizon case is to ascribe full moral responsibility to individuals and to collectives treated as individuals. However, this approach is inappropriate since concrete action and experience in engineering contexts seldom meets the

  14. Progreen Online Engineering Diploma in the Middle East: Assessment of the Educational Experience

    Science.gov (United States)

    Baytiyeh, Hoda

    2018-01-01

    Little is known about the status of online learning in the Middle East. This study investigates educational experiences of engineers enrolled in the new joint online ProGreen diploma programme offered by three universities, two in Lebanon and one in Egypt. Forty-eight working engineers responded to an online survey based on the three components of…

  15. Successful Latina Scientists and Engineers: Their Lived Mentoring Experiences and Career Development

    Science.gov (United States)

    San Miguel, Anitza M.; Kim, Mikyong Minsun

    2015-01-01

    Utilizing a phenomenological perspective and method, this study aimed to reveal the lived career mentoring experiences of Latinas in science and engineering and to understand how selected Latina scientists and engineers achieved high-level positions. Our in-depth interviews revealed that (a) it is important to have multiple mentors for Latinas'…

  16. Investigation of Students' Experiences of Gendered Cultures in Engineering Workplaces

    Science.gov (United States)

    Male, Sally A.; Gardner, Anne; Figueroa, Eugenia; Bennett, Dawn

    2018-01-01

    Women remain severely under-represented in engineering in Australia as in all Western countries. This limits the pool of talent, standpoints and approaches within the profession. Furthermore, this under-representation equates to restriction of the benefits of being an engineer mainly to men. Gendered workplace experiences have been found to…

  17. BC Hydro experiences the power of engineering document management software

    International Nuclear Information System (INIS)

    Wilkins, A.

    2000-01-01

    The recent popularity of electronic document management software (EDMS), specifically designed for engineering CAD/CAM drawings that holds the promise of reducing paper-pushing and freeing up organizational resources for more productive purposes, is discussed. To illustrate how such systems function, a document management system installed at BC Hydro, with over 2,500 users in two main engineering groups is described. The new system - FileNET - replaces several older systems that have been used as stand-alone systems in various divisions of BC Hydro for some time. Instead of integrating the entire file of some 750,000 documents, the new system has complete records of some 70,000 of the most recent CAD drawings and an on-line index to the older file that is used less frequently. Access to the entire storehouse of drawings is said to be fast, efficient and secure. Automated document control procedures during work-in-progress, viewing, redlining capabilities, seamless integration with CAD tools and Web access to drawings from anywhere within the two engineering divisions, are some of the most noteworthy characteristics of the new system. It does not completely replace paper, but it does promise significant streamlining of the paper handling function. It also ensures that BC Hydro's central computer is the prime repository of all documents and drawings, and that this valuable record of environmental. legal, regulatory and other public policy importance is instantly available, without the need to handle paper

  18. Foundations for value education in engineering: the Indian experience.

    Science.gov (United States)

    Gupta, Amitabha

    2015-04-01

    The objective of this paper is to discuss some of the foundational issues centering around the question of integrating education in human values with professional engineering education: its necessity and justification. The paper looks at the efforts in 'tuning' the technical education system in India to the national goals in the various phases of curriculum development. The contribution of the engineering profession in national development and India's self-sufficiency is crucially linked with the institutionalization of expertise and the role of morality and responsibility. This linkage can be created through a proper understanding of the social role of the profession-what motivates the professionals and what makes professional life meaningful. Value education facilitates the process of moral maturity and the development of a 'holistic' mindset. This paper deals with the need to create such a mindset, the human values associated with it and gives examples of efforts to impart such education through 'action-oriented' programmes introduced in some institutes of engineering in India.

  19. Deep repository - Engineered barrier system. Erosion and sealing processes in tunnel backfill materials investigated in laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sanden, Torbjoern; Boergesson, Lennart; Dueck, Ann; Goudarzi, Reza; Loennqvist, Margareta (Clay Technology AB, Lund (Sweden))

    2008-12-15

    SKB in Sweden and Posiva in Finland are developing and plan to implement similar disposal concepts for the final disposal of spent nuclear fuel. Co-operation and joint development work between Posiva and SKB with the overall objective to develop backfill concepts and techniques for sealing and closure of the repository have been going on for several years. The investigation described in this report is intended to acquire more knowledge regarding the behavior of some of the candidate backfilling materials. Blocks made of three different materials (Friedland clay, Asha 230 or a bentonite/ballast 30/70 mixture) as well as different bentonite pellets have been examined. The backfill materials will be exposed to an environment simulating that in a tunnel, with high relative humidity and water inflow from the rock. The processes and properties investigated are: 1. Erosion properties of blocks and pellets (Friedland blocks, MX-80 pellets, Cebogel QSE pellets, Minelco and Friedland granules). 2. Displacements of blocks after emplacement in a deposition drift (Blocks of Friedland, Asha 230 and Mixture 30/70). 3. The ability of these materials to seal a leaking in-situ cast plug cement/rock but also other fractures in the rock (MX-80 pellets). 4. The self healing ability after a piping scenario (Blocks of Friedland, Asha 230 Mixture 30/70 and also MX-80 pellets). 5. Swelling and cracking of the compacted backfill blocks caused by relative humidity. The erosion properties of Friedland blocks were also investigated in Phase 2 of the joint SKBPosiva project 'Backfilling and Closure of the Deep Repository, BACLO, which included laboratory scale experiments. In this phase of the project (3) some completing tests were performed with new blocks produced for different field tests. These blocks had a lower density than intended and this has an influence on the erosion properties measured. The erosion properties of MX-80 pellets were also investigated earlier in the project but

  20. A Modular Artificial Intelligence Inference Engine System (MAIS) for support of on orbit experiments

    Science.gov (United States)

    Hancock, Thomas M., III

    1994-01-01

    This paper describes a Modular Artificial Intelligence Inference Engine System (MAIS) support tool that would provide health and status monitoring, cognitive replanning, analysis and support of on-orbit Space Station, Spacelab experiments and systems.

  1. What Barriers and Facilitators Do School Nurses Experience When Implementing an Obesity Intervention?

    Science.gov (United States)

    Schroeder, Krista; Smaldone, Arlene

    2017-12-01

    A recent evaluation of a school nurse-led obesity intervention demonstrated a 5% implementation rate. The purpose of this study was to explore school nurses' perceived barriers to and facilitators of the intervention in order to understand reasons for the low implementation rate. Methods included semi-structured individual interviews with school nurses. Data were analyzed using content analysis and heat mapping. Nineteen nurses participated and eight themes were identified. Parental and administrative gatekeeping, heavy nurse workload, obesogenic environments, and concerns about obesity stigma were barriers to implementation. Teamwork with parents and school staff was a key facilitator of implementation. Nurses also noted the importance of cultural considerations and highlighted the need to tailor the intervention to the unique needs of their school environment and student population. These findings suggest that for school nurses to play a key role in school-based obesity interventions, barriers must be identified and addressed prior to program implementation.

  2. A study experiment of auto idle application in the excavator engine performance

    Energy Technology Data Exchange (ETDEWEB)

    Purwanto, Wawan, E-mail: wawan5527@gmail.com; Maksum, Hasan; Putra, Dwi Sudarno, E-mail: dwisudarnoputra@ft.unp.ac.id; Wahyudi, Retno [State University of Padang, West Sumatera (Indonesia); Azmi, Meri, E-mail: meriazmi@gmail.com [State Polytechnic of Padang, West Sumatera (Indonesia)

    2016-03-29

    The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

  3. Experiences of girls in a fabrication engineering environment

    CSIR Research Space (South Africa)

    Dlodlo, N

    2009-01-01

    Full Text Available % Mathematical and statistical sciences 6,903 9,505 42 % Biological sciences 11,951 11,831 50 % Physical and chemical sciences 4,575 10,050 31 % Engineering 1,467 30,897 5 % Source: Department of Science and Technology, 2009b. NOT FOR COMMERCIAL US E 130... that the introductory phase of the activities which consisted of explaining to the students was diffi cult to understand. Their eyes were opened when they started implementing the practical aspects. In the Fab Kids lab, the learners are introduced to theory...

  4. What Barriers and Facilitators Do School Nurses Experience When Implementing an Obesity Intervention?

    Science.gov (United States)

    Schroeder, Krista; Smaldone, Arlene

    2017-01-01

    A recent evaluation of a school nurse-led obesity intervention demonstrated a 5% implementation rate. The purpose of this study was to explore school nurses' perceived barriers to and facilitators of the intervention in order to understand reasons for the low implementation rate. Methods included semi-structured individual interviews with school…

  5. Barriers and solutions for expansion of electricity grids—the German experience

    International Nuclear Information System (INIS)

    Steinbach, Armin

    2013-01-01

    There is a lack of synchronization in the expansion of renewable energies and the modernization of the electricity grid infrastructure. Main barriers to grid development are the insufficient regulatory framework, an inefficient allocation of planning and authorization competences and a lack of public acceptance of new grids. As response to these barriers, Germany has implemented a fundamental reform of the planning and authorization of high voltage power lines. We analyze the new regime as to what extent it is able to eliminate existing barriers to grid expansion and thus can serve as model for other countries. We find that the establishment of a single authority competent for planning, authorization and regulation may abolish existing lack of coordination. Also, the implementation of early participation on basis of various consultations phases has been proved to be very successful in the establishment of the first grid development plan. Stricter administrative time-limits and sanctions are likely to have an accelerating effect. And an increased openness to new technologies on basis of pilot project gives grid operators more flexibility in grid development. Recently, the European Commission adopted the German approach in its policy guidelines for other EU members. - Highlights: • Assessment of barriers to electricity grid infrastructure. • Needs for better, simplified and uniform regulatory framework. • German reform of planning and authorization procedure

  6. Barriers to contraceptive careseeking: the experience of Eritrean asylum-seeking women in Israel.

    Science.gov (United States)

    Gebreyesus, Tsega; Gottlieb, Nora; Sultan, Zebib; Ghebrezghiabher, Habtom Mehari; Tol, Wietse; Winch, Peter J; Davidovitch, Nadav; Surkan, Pamela J

    2017-12-28

    In recent years, there has been a mass migration of Eritreans (many seeking political asylum) into Israel after precarious irregular movement across international borders. This study qualitatively explores the structural barriers to family planning (i.e. contraceptive services) for Eritrean women in Israel that are rooted in their temporary legal status and the patchwork of family planning services. From December 2012 to September 2013, we interviewed 25 key informants (NGO workers, researchers, Eritrean community activists, International NGO representatives and Ministry of Health officials) and 12 Eritrean asylum seekers. We also conducted 8 focus groups with Eritrean asylum seekers. Data were analyzed using both inductive and deductive coding. We identified 7 main barriers to accessing family planning services: (1) distance to health facilities; (2) limited healthcare resources; (3) fragmentation of the healthcare system; (4) cost of contraceptive services; (5) low standard of care in private clinics; (6) discrimination; and (7) language barriers. The political, economic and social marginalization of Eritrean asylum-seeking women in Israel creates structural barriers to family planning services. Their marginalization complicates providers' efforts (NGO and governmental) to provide them with comprehensive healthcare, and hinders their ability to control their sexual and reproductive health. Failure to act on this evidence may perpetuate the pattern of unwanted pregnancies and social and economic disparities in this population.

  7. Engineered Barrier System - Mechanical Integrity of KBS-3 Spent Fuel Canisters. Report from a Workshop. Synthesis and extended abstracts

    Energy Technology Data Exchange (ETDEWEB)

    2007-09-15

    SKI is preparing to review the license applications being developed by the Swedish Nuclear Fuel and Waste Management Company (SKB) for a final repository for the geological disposal of spent nuclear fuel in the year 2009. As part of its preparation, SKI is conducting a series of technical workshops on key aspects of the Engineered Barrier System (EBS). The workshop reported here mainly dealt with the mechanical integrity of KBS-3 spent fuel canisters. This included assessment and review of various loading conditions, structural integrity models and mechanical properties of the copper shell and the cast iron insert. Degradation mechanisms such as stress corrosion cracking and brittle creep fracture were also briefly addressed. Previous workshops have addressed the overall concept for long-term integrity of the EBS, the manufacturing, testing and QA of the EBS, the performance confirmation for the EBS, long-term stability of the buffer and the backfill, corrosion properties of copper canisters and the spent fuel dissolution and source term modelling. The goal of ongoing review work in connection of the workshop series is to achieve a comprehensive overview of all aspects of SKB's EBS and spent fuel work prior to the handling of the forthcoming license application. This report aims to summarise the issues discussed at the workshop and to extract the essential viewpoints that have been expressed. The report is not a comprehensive record of all the discussions at the workshop, and individual statements made by workshop participants should be regarded as personal opinions rather than SKI viewpoints. Results from the EBS workshops series will be used as one important basis in future review work. This reports includes in addition to the workshop synthesis, questions to SKB identified prior to the workshop, and extended abstracts for introductory presentations

  8. Closing the loop on improvement: Packaging experience in the Software Engineering Laboratory

    Science.gov (United States)

    Waligora, Sharon R.; Landis, Linda C.; Doland, Jerry T.

    1994-01-01

    As part of its award-winning software process improvement program, the Software Engineering Laboratory (SEL) has developed an effective method for packaging organizational best practices based on real project experience into useful handbooks and training courses. This paper shares the SEL's experience over the past 12 years creating and updating software process handbooks and training courses. It provides cost models and guidelines for successful experience packaging derived from SEL experience.

  9. Migrant Sexual Health Help-Seeking and Experiences of Stigmatization and Discrimination in Perth, Western Australia: Exploring Barriers and Enablers.

    Science.gov (United States)

    Agu, Josephine; Lobo, Roanna; Crawford, Gemma; Chigwada, Bethwyn

    2016-05-11

    Increasing HIV notifications amongst migrant and mobile populations to Australia is a significant public health issue. Generalizations about migrant health needs and delayed or deterred help-seeking behaviors can result from disregarding the variation between and within cultures including factors, such as drivers for migration and country of birth. This study explored barriers and enablers to accessing sexual health services, including experiences of stigma and discrimination, within a purposive sample of sub-Saharan African, Southeast Asian, and East Asian migrants. A qualitative design was employed using key informant interviews and focus group discussions. A total of 45 people with ages ranging from 18 to 50 years, participated in focus group discussions. Common barriers and enablers to help seeking behaviors were sociocultural and religious influence, financial constraints, and knowledge dissemination to reduce stigma. Additionally, common experiences of stigma and discrimination were related to employment and the social and self-isolation of people living with HIV. Overcoming barriers to accessing sexual health services, imparting sexual health knowledge, recognizing variations within cultures, and a reduction in stigma and discrimination will simultaneously accelerate help-seeking and result in better sexual health outcomes in migrant populations.

  10. Migrant Sexual Health Help-Seeking and Experiences of Stigmatization and Discrimination in Perth, Western Australia: Exploring Barriers and Enablers

    Directory of Open Access Journals (Sweden)

    Josephine Agu

    2016-05-01

    Full Text Available Increasing HIV notifications amongst migrant and mobile populations to Australia is a significant public health issue. Generalizations about migrant health needs and delayed or deterred help-seeking behaviors can result from disregarding the variation between and within cultures including factors, such as drivers for migration and country of birth. This study explored barriers and enablers to accessing sexual health services, including experiences of stigma and discrimination, within a purposive sample of sub-Saharan African, Southeast Asian, and East Asian migrants. A qualitative design was employed using key informant interviews and focus group discussions. A total of 45 people with ages ranging from 18 to 50 years, participated in focus group discussions. Common barriers and enablers to help seeking behaviors were sociocultural and religious influence, financial constraints, and knowledge dissemination to reduce stigma. Additionally, common experiences of stigma and discrimination were related to employment and the social and self-isolation of people living with HIV. Overcoming barriers to accessing sexual health services, imparting sexual health knowledge, recognizing variations within cultures, and a reduction in stigma and discrimination will simultaneously accelerate help-seeking and result in better sexual health outcomes in migrant populations.

  11. Technical note 5. SR-Site Independent Modelling of Engineered Barrier Evolution and Coupled THMC. Contribution to the Initial Review Phase

    International Nuclear Information System (INIS)

    Benbow, Steven; Metcalfe, Richard; Watson, Claire; Bond, Alex

    2012-06-01

    This review has focussed mainly on the modelling of the Engineered Barrier System (EBS) evolution, which includes coupled thermal, hydraulic, mechanical and chemical (THMC) processes. Additionally, the role of the EBS in the wider safety case was reviewed, including its treatment in scenarios and its representation in conceptual models since this provided the motivation for the modelling work that was undertaken by SKB. The scope of the work described here was to: 1. Review relevant documents concerning SKB's modelling; and 2. Check one particular modelling area that was judged to be important, based on this review, with a limited set of independent modelling/calculations. The review covers the early resaturation and swelling / homogenisation of the buffer; the longer-term chemical evolution of the buffer and backfill, corrosion of the copper canister and the chemical and hydrogeological boundary conditions provided by the surrounding host rock. The reviewers consider that SKB's modelling of engineered barrier performance generally supports their conclusion that the barriers will perform as required. However, there remain issues that are not addressed and uncertainties that are not explored adequately by SKB's modelling. The thermo-hydro-mechanical modelling of buffer resaturation that is performed by SKB is based on demonstrating a fit to measurements from the in-situ Canister Retrieval Test (CRT) experiment. The modelling reproduces some of the experimental observations very well, but some key experimental measurements are not considered. In particular, investigation of the fit to the measured rates of water inflow, which are a critical factor controlling the rate at which the buffer will resaturate, is not given, Furthermore, the water supply boundary conditions imposed on the CRT are not considered to be representative of those that might be expected in repository conditions. From the information that it is presented it is therefore not possible to be confident

  12. Engineering Status of the Fusion Ignition Research Experiment (FIRE)

    International Nuclear Information System (INIS)

    Heitzenroeder, Philip J.; Meade, Dale; Thome, Richard J.

    2000-01-01

    FIRE is a compact, high field tokamak being studied as an option for the next step in the US magnetic fusion energy program. FIRE's programmatic mission is to attain, explore, understand, and optimize alpha-dominated plasmas to provide the knowledge necessary for the design of attractive magnetic fusion energy systems. This study began in 1999 with broad participation of the US fusion community, including several industrial participants. The design under development has a major radius of 2 m, a minor radius of 0.525 m, a field on axis of 10T and capability to operate at 12T with upgrades to power supplies. Toroidal and poloidal field magnets are inertially cooled with liquid nitrogen. An important goal for FIRE is a total project cost in the $1B range. This paper presents an overview of the engineering details which were developed during the FIRE preconceptual design study in FY99 and 00

  13. Engineering test station for TFTR blanket module experiments

    International Nuclear Information System (INIS)

    Jassby, D.L.; Leinoff, S.

    1979-12-01

    A conceptual design has been carried out for an Engineering Test Station (ETS) which will provide structural support and utilities/instrumentation services for blanket modules positioned adjacent to the vacuum vessel of the TFTR (Tokamak Fusion Test Reactor). The ETS is supported independently from the Test Cell floor. The ETS module support platform is constructed of fiberglass to eliminate electromagnetic interaction with the pulsed tokamak fields. The ETS can hold blanket modules with dimensions up to 78 cm in width, 85 cm in height, and 105 cm in depth, and with a weight up to 4000 kg. Interfaces for all utility and instrumentation requirements are made via a shield plug in the TFTR igloo shielding. The modules are readily installed or removed by means of TFTR remote handling equipment

  14. Chemical engineering in fuel reprocessing. The French experience

    International Nuclear Information System (INIS)

    Viala, M.; Sombret, C.; Bernard, C.; Miquel, P.; Moulin, J.P.

    1992-01-01

    Reprocessing is the back-end of the nuclear fuel cycle, designed to recover valuable fissile materials, especially plutonium, and to condition safely all the wastes ready for disposal. For its new commercial reprocessing plants (UP 3 and UP 2 800) COGEMA decided to include many engineering innovations as well as new processes and key-components developed by CEA. UP 3 is a complete new plant with a capacity of 800 t/y which was put in operation in August 1990. UP 2 800 is an extension of the existing UP 2 facility, designed to achieve the same annual capacity of 800 t/y, to be put in operation at the end of 1993 by the commissioning of a new head-end and highly active chemical process facilities

  15. Software engineering and data management for automated payload experiment tool

    Science.gov (United States)

    Maddux, Gary A.; Provancha, Anna; Chattam, David

    1994-01-01

    The Microgravity Projects Office identified a need to develop a software package that will lead experiment developers through the development planning process, obtain necessary information, establish an electronic data exchange avenue, and allow easier manipulation/reformatting of the collected information. An MS-DOS compatible software package called the Automated Payload Experiment Tool (APET) has been developed and delivered. The objective of this task is to expand on the results of the APET work previously performed by University of Alabama in Huntsville (UAH) and provide versions of the software in a Macintosh and Windows compatible format. Appendix 1 science requirements document (SRD) Users Manual is attached.

  16. CURRENT DRIVE AND PRESSURE PROFILE MODIFICATION WITH ELECTRON CYCLOTRON POWER IN DIII-D QUIESCENT DOUBLE BARRIER EXPERIMENTS

    International Nuclear Information System (INIS)

    CASPER, TA; BURRELL, KH; DOYLE, EJ; GOHIL, P; GREENFIELD, CM; GROEBNER, RJ; JAYAKUMAR, RJ; MAKOWSKI, MA; RHODES, TL; WEST, WP

    2003-01-01

    OAK-B135 High confinement mode (H-mode) operation is a leading scenario for burning plasma devices due to its inherently high energy-confinement characteristics. The quiescent H-mode (QH-mode) offers these same advantages with the additional attraction of more steady edge conditions where the highly transient power loads due to edge localized mode (ELM) activity is replaced by the steadier power and particle losses associated with an edge harmonic oscillation (EHO). With the addition of an internal transport barrier (ITB), the capability is introduced for independent control of both the edge conditions and the core confinement region giving potential control of fusion power production for an advanced tokamak configuration. The quiescent double barrier (QDB) conditions explored in DIII-D experiments exhibit these characteristics and have resulted in steady plasma conditions for several confinement times (∼ 26 τ E ) with moderately high stored energy, β N H 89 ∼ 7 for 10 τ E

  17. Effects of thermal barrier coating on gas emissions and performance of a LHR engine with different injection timings and valve adjustments

    International Nuclear Information System (INIS)

    Bueyuekkaya, Ekrem; Engin, Tahsin; Cerit, Muhammet

    2006-01-01

    Tests were performed on a six cylinder, direct injection, turbocharged Diesel engine whose pistons were coated with a 350 μm thickness of MgZrO 3 over a 150 μm thickness of NiCrAl bond coat. CaZrO 3 was employed as the coating material for the cylinder head and valves. The working conditions for the standard engine (uncovered) and low heat rejection (LHR) engine were kept exactly the same to ensure a realistic comparison between the two configurations of the engine. Comparisons between the standard engine and its LHR version were made based on engine performance, exhaust gas emissions, injection timing and valve adjustment. The results showed that 1-8% reduction in brake specific fuel consumption could be achieved by the combined effect of the thermal barrier coating (TBC) and injection timing. On the other hand, NO x emissions were obtained below those of the base engine by 11% for 18 o BTDC injection timing

  18. Multiple case study analysis of young women's experiences in high school engineering

    Science.gov (United States)

    Pollock, Meagan C.

    At a time when engineers are in critical demand, women continue to be significantly underrepresented in engineering fields (11.7%) and degree programs (21.3%) in the United States. As a result, there is a national demand for improved K-12 STEM education and targeted efforts to improve equity and access to engineering and science careers for every underrepresented group. High school engineering has become a nascent and growing market for developers and an emergent opportunity for students across the United States to learn introductory engineering skills through strategic career pathways; however there is a disparity in participation at this level as well. Much useful research has been used to examine the problematization of underrepresentation (K Beddoes, 2011), but there is a dearth of literature that helps us to understand the experiences of young women in high school engineering. By examining the experiences of young women in high school engineering, we can learn ways to improve the curriculum, pedagogy, and environment for underrepresented groups such as females to ensure they have equitable access to these programs and are subsequently motivated to persist in engineering. Understanding the needs of marginalized groups is complex, and intersectional feminism seeks to understand gender in relation to other identities such as race, class, ethnicity, sexuality, and nationality. This theory asserts that gender alone is neither a total identity nor a universal experience, and it is thus advantageous to consider each of the intersecting layers of identity so as to not privilege a dominate group as representative of all women. Thus, to understand how female students engage with and experience engineering in grade school, it is useful to examine through the lens of gender, class, race, and sexuality, because this intersection frames much of the human experience. The purpose of this study is to examine high school females' experiences in engineering, with a goal to

  19. Attitudes, experiences, and barriers to research and publishing among dental postgraduate students of Bengaluru City: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Aditi Hegde

    2017-01-01

    Full Text Available Background: Research experience not only enhances understanding but also instills evidence-based practice and improves skills. A natural successor to research is academic publishing. Unfortunately, student research itself is plagued by a number of barriers. Aim: To identify the attitudes, experiences, and barriers to research and publishing among dental postgraduate students of Bangalore city. Materials and Methods: A cross-sectional survey using purposive sampling technique was conducted among the dental postgraduate students of all specialties in Bengaluru city in the months of July–August 2015. A prevalidated, close-ended, self-administered questionnaire consisting of 26 questions was used. Data from 638 completed questionnaires were entered into and analyzed using Microsoft Excel 2013 and SPSS software version 14. Results: The majority of the students displayed a positive attitude towards research and stated that they would like more opportunities to take part in research (89%. Most students were positive toward publishing research; 94% agreed that it is important to publish, although only 43.7% had submitted an article for publication. The single most often stated barrier to conducting research was a lack of funding from the institution (15.7%, followed by workload and time constraints (15.0%. Lack of training and good mentorship was the most often (23.3% faced barrier to publishing, along with high publication fee for indexed journals (17.9%. Conclusion: Dental postgraduate students show an urge to conduct research and publish their results. Research-related workshops for teachers and students are suggestions for improving the status of research in dental colleges.

  20. Enhancing the Student Learning Experience in Software Engineering Project Courses

    Science.gov (United States)

    Marques, Maira; Ochoa, Sergio F.; Bastarrica, Maria Cecilia; Gutierrez, Francisco J.

    2018-01-01

    Carrying out real-world software projects in their academic studies helps students to understand what they will face in industry, and to experience first-hand the challenges involved when working collaboratively. Most of the instructional strategies used to help students take advantage of these activities focus on supporting agile programming,…

  1. On Design Experiment Teaching in Engineering Quality Cultivation

    Science.gov (United States)

    Chen, Xiao

    2008-01-01

    Design experiment refers to that designed and conducted by students independently and is surely an important method to cultivate students' comprehensive quality. According to the development and requirements of experimental teaching, this article carries out a study and analysis on the purpose, significance, denotation, connotation and…

  2. A Gamification Experience to Improve Engineering Students' Performance through Motivation

    Science.gov (United States)

    Sánchez-Carmona, Adrián; Robles, Sergi; Pons, Jordi

    2017-01-01

    The students' lack of motivation is a usual problem. The students value more the obtention of the degree than the developing of competences and skills. In order to fight this, we developed a gamification's experience based on merits and leaderboards. The merits are linked to the attainment of skills and competences that students usually do not…

  3. High temperature engineering research facilities and experiments in Russia

    International Nuclear Information System (INIS)

    Kodochigov, N.G.; Kuzavkov, N.G.; Sukharev, Y.P.; Chudin, A.G.

    1998-01-01

    An overview is given of the characteristics of the experimental facilities and experiments in the Russian Federation: the HTGR neutron-physical investigation facilities ASTRA and GROG; facilities for fuel, graphite and other elements irradiation; and thermal hydraulics experimental facilities. The overview is presented in the form of copies of overhead sheets

  4. Kuwaiti engineers' perspectives of the engineering senior design (Capstone) course as related to their professional experiences

    Science.gov (United States)

    Alsagheer, Abdullah

    This study looks into transfer of learning and its application in the actual employment of engineering students after graduation. At Kuwait University, a capstone course is being offered that aims to ensure that students amalgamate all kinds of engineering skills to apply to their work. Within a basic interpretive, qualitative study-design methodology, I interviewed 12 engineers who have recently experienced the senior design course at Kuwait University and are presently working in industry. From the analysis, four basic themes emerged that further delineate the focus of the entire study. The themes are 1) need for the capstone course, 2) applicability of and problems with the capstone course, 3) industry problems with training, and 4) students' attitudes toward the capstone course. The study concludes that participants are not transferring engineering skills; rather, they are transferring all types of instructions they have been given during their course of study at the university. A frequent statement is that the capstone course should be improved and specifically that it is necessary to improve upon the timing, schedule, teachers' behavior, contents, and format. The study concludes that Kuwaiti engineers on the whole face problems with time management and management support. The study includes some implications for Kuwait University and recommendations that can provide significant support for the development of the Senior Design (Capstone) Course. For examples: the project must be divided into phases to ensure timely completion of deliverables. In order to motivate students for hard work and to achieve true transfer of learning, Kuwait University is required to communicate with certain organizations to place its students at their research centers for capstone projects. All universities, including Kuwait University, should hire faculty specifically to run the capstone course. In conclusion, the study includes some suggestions for further research studies focused

  5. Experiences and Perceptions of Barriers to Health Services for Elderly in Rural Namibia

    Directory of Open Access Journals (Sweden)

    Gert Van Rooy

    2015-07-01

    Full Text Available We investigate barriers to accessing health facilities (e.g., transportation and cost of services and health service delivery barriers (e.g., timeliness of services scheduling of appointments, language that the literature suggest are operative. Semistructured interviews were utilized with respondents in three purposefully selected regional research sites in Namibia. All questions were translated into local languages. It is found that although many senior citizens appreciate the use of modern health care and are exempted from paying health care consultation fees, they still prefer to use traditional health medicine because of the long distance to health care facilities, which when they decide to travel translates into high transportation costs. Referrals to hospitals become very expensive. There is a need to consider the unique issues (extended family system affecting access to health care for elderly people in Namibia to achieve equitable access to health care services.

  6. The Lattice and Thermal Radiation Conductivity of Thermal Barrier Coatings: Models and Experiments

    Science.gov (United States)

    Zhu, Dongming; Spuckler, Charles M.

    2010-01-01

    The lattice and radiation conductivity of ZrO2-Y2O3 thermal barrier coatings was evaluated using a laser heat flux approach. A diffusion model has been established to correlate the coating apparent thermal conductivity to the lattice and radiation conductivity. The radiation conductivity component can be expressed as a function of temperature, coating material scattering, and absorption properties. High temperature scattering and absorption of the coating systems can be also derived based on the testing results using the modeling approach. A comparison has been made for the gray and nongray coating models in the plasma-sprayed thermal barrier coatings. The model prediction is found to have a good agreement with experimental observations.

  7. Culture as a barrier to rural women's entrepreneurship: experience from Zimbabwe.

    Science.gov (United States)

    Chitsike, C

    2000-03-01

    This article identifies the important issues addressed by programs and projects that are aimed at promoting women's equality through entrepreneurship and suggests several actions for future focus of gender programs and training. Culture was seen as a barrier to the self-confident and autonomous economic activities of women in Zimbabwe. Likewise, structural barriers such as lack of marketable skills, time and ability to travel, land and assets, education, and position as primary family providers all compounded to the problem of entrepreneurship among women. Establishment of policy approaches for women like vocational skills training augmented by training in business skills and marketing, however, are insufficient since it failed to discuss and transfer behavioral skills necessary to make one an entrepreneur. To conclude, programs must be designed to empower personal skills and self-awareness, as well as address the constraints to entrepreneurship, and macroeconomic policy change.

  8. National Educators' Workshop: Update 1991. Standard Experiments in Engineering Materials Science and Technology

    International Nuclear Information System (INIS)

    Gardner, J.E.; Jacobs, J.A.; Stiegler, J.O.

    1992-06-01

    Given here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 91, held at the Oak Ridge National Laboratory on November 12-14, 1991. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community

  9. Software Engineering Researchers' Attitudes on Case Studies and Experiments : an Exploratory Survey

    NARCIS (Netherlands)

    Tofan, Dan; Galster, Matthias; Avgeriou, Paris; Weyns, Danny

    2011-01-01

    Background: Case studies and experiments are research methods frequently applied in empirical software engineering. Experiments are well-­understood and their value as an empirical method is recognized. On the other hand, there seem to be different opinions on what constitutes a case study, and

  10. Optimal Design of Experiments for Parametric Identification of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    Optimal Systems of experiments for parametric identification of civil engineering structures is investigated. Design of experiments for parametric identification of dynamic systems is usually done by minimizing a scalar measure, e.g the determinant, the trace ect., of an estimated parameter...

  11. A business process modeling experience in a complex information system re-engineering.

    Science.gov (United States)

    Bernonville, Stéphanie; Vantourout, Corinne; Fendeler, Geneviève; Beuscart, Régis

    2013-01-01

    This article aims to share a business process modeling experience in a re-engineering project of a medical records department in a 2,965-bed hospital. It presents the modeling strategy, an extract of the results and the feedback experience.

  12. National Educators' Workshop: Update 1988. Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1990-01-01

    Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 88, held May 10 to 12, 1988 at the National Institute of Standards and Technology (NIST), Gaithersberg, Maryland. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  13. National Educators' Workshop: Update 1989 Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1990-01-01

    Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 89, held October 17 to 19, 1989 at the National Aeronautics and Space Administration, Hampton, Virginia. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  14. National Educators' Workshop: Update 95. Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A.; Karnitz, Michael A.

    1996-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 95. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  15. National Educators' Workshop: Update 1993. Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1994-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 93 held at the NASA Langley Research Center in Hampton, Virginia, on November 3-5, 1993. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  16. National Educators' Workshop: Update 1991. Standard Experiments in Engineering Materials Science and Technology

    Science.gov (United States)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler); Stiegler, James O. (Compiler)

    1992-01-01

    Given here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 91, held at the Oak Ridge National Laboratory on November 12-14, 1991. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  17. The Characteristics and Experiences of Successful Undergraduate Latina Students Who Persist in Engineering

    Science.gov (United States)

    Robinson, Carrie

    Females and underrepresented ethnic minorities earn a small percentage of engineering and computer science bachelor's degrees awarded in the United States, earn an even smaller proportion of master's and doctoral degrees, and are underrepresented in the engineering workforce (Engineering Workforce Commission, [2006], as cited in National Science Foundation, 2012; United States Department of Education, [2006], as cited in National Science Foundation, 2009a; United States Department of Education, [2006], as cited in National Science Foundation, 2009b). Considerable research has examined the perceptions, culture, curriculum, and pedagogy in engineering that inhibits the achievement of women and underrepresented ethnic minorities. This action research study used a qualitative approach to examine the characteristics and experiences of Latina students who pursued a bachelor's degree in the Ira A. Fulton Schools of Engineering at Arizona State University (ASU) as part of the 2008 first-time full-time freshman cohort. The researcher conducted two semi-structured individual interviews with seven undergraduate Latina students who successfully persisted to their fourth (senior) year in engineering. The researcher aimed to understand what characteristics made these students successful and how their experiences affected their persistence in an engineering major. The data collected showed that the Latina participants were motivated to persist in their engineering degree program due to their parents' expectations for success and high academic achievement; their desire to overcome the discrimination, stereotyping, and naysayers that they encountered; and their aspiration to become a role model for their family and other students interested in pursuing engineering. From the data collected, the researcher provided suggestions to implement and adapt educational activities and support systems within the Ira A. Fulton Schools of Engineering to improve the retention and graduation rates

  18. Rocket Engine Turbine Blade Surface Pressure Distributions Experiment and Computations

    Science.gov (United States)

    Hudson, Susan T.; Zoladz, Thomas F.; Dorney, Daniel J.; Turner, James (Technical Monitor)

    2002-01-01

    Understanding the unsteady aspects of turbine rotor flow fields is critical to successful future turbine designs. A technology program was conducted at NASA's Marshall Space Flight Center to increase the understanding of unsteady environments for rocket engine turbines. The experimental program involved instrumenting turbine rotor blades with miniature surface mounted high frequency response pressure transducers. The turbine model was then tested to measure the unsteady pressures on the rotor blades. The data obtained from the experimental program is unique in two respects. First, much more unsteady data was obtained (several minutes per set point) than has been possible in the past. Also, an extensive steady performance database existed for the turbine model. This allowed an evaluation of the effect of the on-blade instrumentation on the turbine's performance. A three-dimensional unsteady Navier-Stokes analysis was also used to blindly predict the unsteady flow field in the turbine at the design operating conditions and at +15 degrees relative incidence to the first-stage rotor. The predicted time-averaged and unsteady pressure distributions show good agreement with the experimental data. This unique data set, the lessons learned for acquiring this type of data, and the improvements made to the data analysis and prediction tools are contributing significantly to current Space Launch Initiative turbine airflow test and blade surface pressure prediction efforts.

  19. SGN's Dismantling and Decommissioning engineering, projects experience and capabilities

    International Nuclear Information System (INIS)

    Destrait, L.

    <