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)

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.

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.

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.

La nouvelle-tableau (2

Directory of Open Access Journals (Sweden)

Géraldine Jenvrin

2012-06-01

Full Text Available La nouvelle « Frémissante, la feuille se flétrit » met en scène le trouble d'un détenu qui par les seuls objets dont il dispose, lutte pour s'échapper intérieurement. L'usage du regard cinématographique porté sur les détails infimes de la matérialité carcérale, leur exposition sous forme de tableaux se faisant échos, les techniques de l’anonymat et du brouillage des repères objectifs, portent à son comble les dimensions énigmatiques et l'esthétique de la  brièveté propre à la nouvelle tout en permettant de  représenter la résistance de l'homme à l'enfermement et à la persécution.

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

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

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

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

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

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

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.

Nouvelles et activités | Page 6 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Consultez les nouvelles et les activités. Utilisez cet outil de recherche pour trouver des nouvelles ou des activités précis dans le site Web du CRDI. Content type. Tout. Activités. Avis aux médias. Bulletins. Communiqués. Nouvelle ...

Nouvelles et activités | Page 2 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Consultez les nouvelles et les activités. Utilisez cet outil de recherche pour trouver des nouvelles ou des activités précis dans le site Web du CRDI. Content type. Tout. Activités. Avis aux médias. Bulletins. Communiqués. Nouvelle ...

Nouvelles et activités | Page 7 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Consultez les nouvelles et les activités. Utilisez cet outil de recherche pour trouver des nouvelles ou des activités précis dans le site Web du CRDI. Content type. Tout. Activités. Avis aux médias. Bulletins. Communiqués. Nouvelle ...

Nouvelles et activités | Page 5 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Consultez les nouvelles et les activités. Utilisez cet outil de recherche pour trouver des nouvelles ou des activités précis dans le site Web du CRDI. Content type. Tout. Activités. Avis aux médias. Bulletins. Communiqués. Nouvelle ...

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

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.

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

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.)

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.)

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

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

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

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.

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

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.

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.

EDF Energies Nouvelles. Consolidated financial statements at 31 December 2008 Prepared in accordance with IFRSs

International Nuclear Information System (INIS)

2009-01-01

EDF Energies Nouvelles is a world leader in renewable energy electricity. The company develops, builds and operates clean energy power plants both for its own account and for third parties. Historically, EDF Energies Nouvelles primarily developed its business in two geographical areas, Europe and North America (U.S., Canada and Mexico). EDF Energies Nouvelles is a subsidiary of EDF, helping the Group to achieve its renewable energy goals. The EDF Group generates low-carbon electricity around the world and actively participates in the energy transition. EDF Energies Nouvelles prioritizes development of wind and photovoltaic solar capacity. As an integrated operator with global reach, EDF Energies Nouvelles covers the entire renewable energy chain, from development to operation and maintenance, and manages all project phases in-house. This document is EDF Energies Nouvelles's registration document for the year 2008. It contains information about Group profile, governance, business, investments, property, plant and equipment, management, financial position, employees, shareholders, etc. The document includes the group's consolidated financial statements at 31 December 2008

EDF Energies Nouvelles. Consolidated financial statements at 31 December 2007 Prepared in accordance with IFRSs

International Nuclear Information System (INIS)

2008-01-01

EDF Energies Nouvelles is a world leader in renewable energy electricity. The company develops, builds and operates clean energy power plants both for its own account and for third parties. Historically, EDF Energies Nouvelles primarily developed its business in two geographical areas, Europe and North America (U.S., Canada and Mexico). EDF Energies Nouvelles is a subsidiary of EDF, helping the Group to achieve its renewable energy goals. The EDF Group generates low-carbon electricity around the world and actively participates in the energy transition. EDF Energies Nouvelles prioritizes development of wind and photovoltaic solar capacity. As an integrated operator with global reach, EDF Energies Nouvelles covers the entire renewable energy chain, from development to operation and maintenance, and manages all project phases in-house. This document is EDF Energies Nouvelles's registration document for the year 2007. It contains information about Group profile, governance, business, investments, property, plant and equipment, management, financial position, employees, shareholders, etc. The document includes the group's consolidated financial statements at 31 December 2007

EDF Energies Nouvelles. Consolidated financial statements at 31 December 2006 Prepared in accordance with IFRSs

International Nuclear Information System (INIS)

2007-01-01

EDF Energies Nouvelles is a world leader in renewable energy electricity. The company develops, builds and operates clean energy power plants both for its own account and for third parties. Historically, EDF Energies Nouvelles primarily developed its business in two geographical areas, Europe and North America (U.S., Canada and Mexico). EDF Energies Nouvelles is a subsidiary of EDF, helping the Group to achieve its renewable energy goals. The EDF Group generates low-carbon electricity around the world and actively participates in the energy transition. EDF Energies Nouvelles prioritizes development of wind and photovoltaic solar capacity. As an integrated operator with global reach, EDF Energies Nouvelles covers the entire renewable energy chain, from development to operation and maintenance, and manages all project phases in-house. This document is EDF Energies Nouvelles's registration document for the year 2006. It contains information about Group profile, governance, business, investments, property, plant and equipment, management, financial position, employees, shareholders, etc. The document includes the group's Consolidated financial statements at 31 December 2006

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...

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

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 ...

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.

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).

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)

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

Jean Gadrey, Nouvelle économie, nouveau mythe ?

Directory of Open Access Journals (Sweden)

Diane-Gabrielle Tremblay

2002-10-01

Full Text Available La « nouvelle économie » est partout dans les médias nord-américains, comme européens. L’ouvrage de Jean Gadrey est rafraîchissant, car il présente une critique et une analyse minutieuse du concept, de son apparition, des développements qui y sont associés, des thèses et idées défendues au nom de la « nouvelle économie ».Comme il le note bien « les mythes mobilisateurs fleurissent, mais la réflexion sur les contours de cet âge et sur les risques sociaux à prévenir est inexistante : les formul...

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

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

L’Observatoire numérique Nouvelle-Calédonie

Directory of Open Access Journals (Sweden)

Charlotte Ullmann

2013-06-01

Full Text Available Ses missions consistent à observer le développement numérique et favoriser l’animation territoriale des acteurs en Nouvelle-Calédonie. Parrainée par l’association calédonienne pour les technologies de l’information et de la communication (ACTIC et le ministère en charge de l’économie numérique du Gouvernement de Nouvelle-Calédonie nommé depuis mai 2009, une mission d’étude a été menée depuis juin 2010 pour définir les contours d’un Observatoire numérique. A travers cette étude, il s’agissai...

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…

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)

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

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

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)

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)

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.

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

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

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.

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

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

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.)

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.)

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

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)

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

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)

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

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

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)

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)

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)

Access. Challenge for Change/Societe Nouvelle Number Eleven.

Science.gov (United States)

Prinn, Elizabeth, Ed.

Access is a journal published three or four times a year by Challenge for Change/Societe Nouvelle (CCSN). CCSN is an experimental program established by the Government of Canada as a cooperative effort between the National Film Board of Canada and certain of the Government's departments. Its purposes are to improve communications, create greater…

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

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.

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.

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

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

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

Access. Challenge for Change/Societe Nouvelle Number Twelve.

Science.gov (United States)

Prinn, Elizabeth, Ed.; Henaut, Dorothy Todd, Ed.

This issue of Access, the journal issued periodically by Challenge for Change/Societe Nouvelle, contains two groups of articles. The first focuses upon the Skyriver Project, relating how a project was developed which used film and video tape as a means of helping Alaskan communities to assess their own needs and to advocate for themselves the…

Un littoral sableux en progradation : le lido entre Leucate et Port-la-Nouvelle (Aude, Golfe du Lion, France

Directory of Open Access Journals (Sweden)

Jean-Pierre Larue

2009-11-01

Full Text Available L'étude multichronique de photographies aériennes révèle que le lido entre Leucate et Port-la-Nouvelle (Aude a progradé d'environ 15 % en largeur, entre 1952 et 2008. L'analyse sédimentologique permet de montrer que cette progradation exceptionnelle en période d'élévation du niveau marin est due à la présence de barres pré-littorales volumineuses et bien alimentées par la dérive littorale et le transport éolien effectué par les vents de terre. Cependant, du fait de la montée actuelle du niveau marin (2,5 à 3 mm/an et malgré la poursuite de l'accrétion, le lido subit des inondations de plus en plus fréquentes entre le cordon actuel et l'ancien cordon romain.A kinematic study of vertical aerial photos taken between 1952 and 2008 reveals that the Leucate-Port-la-Nouvelle lido (Aude has prograded of about 15 % in width. A sedimentological analysis allows us to explain this accretion caused by drift and wind which supply abundant nearshore bars. In spite of this progradation, frequent floodings, favoured by sea level rise (2.5 to 3 mm-1.year, occur between the present coastal bar and the Roman barrier.

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

Nouvelle espèce des Syntomides (Lepidoptera Heterocera)

NARCIS (Netherlands)

Snellen, P.C.T.

1886-01-01

Quatre mâles frais et bien conservés de 58—64 millim. d’envergure. Cette nouvelle espèce, gigantesque pour une Syntomide, appartient au genre Automolis, tel qu’il a été défini par Herrich-Schäffer, dans son ouvrage »Sammlung aussereuropäischer Schmetterlinge” (p. 21); le nom est emprunté au bien

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

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

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

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

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

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

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)

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.

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

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

Performances d'une nouvelle approche dans l'estimation au champ

African Journals Online (AJOL)

ACSS

Elle possède cependant des limitations, dues à l'organisation temporaire d'une .... Performances d'une nouvelle approche dans l'estimation au champ utilisant le principe de la ... différents types de résidus (soja, luzerne, haricot et maïs) et ...

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)

Toxoplasmose : une nouvelle approche vaccinale à base de nanoparticules d’amidon donne des résultats prometteurs

OpenAIRE

Le Rouzic, Jacques

2015-01-01

Pour lutter contre la toxoplasmose chez les ovins, des chercheurs de l’INRA, de l’Université de Tours et de la Faculté de Médecine de Lille ont développé une nouvelle approche vaccinale, utilisant des nanoparticules d’amidon et une administration par voie muqueuse. Cette approche ouvre de nouvelles perspectives vers des vaccins plus sûrs et plus efficaces.

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)

La viticulture bio, une nouvelle modernité

OpenAIRE

Raphaël Schirmer

2004-01-01

Les difficultés d'expansion de la viticulture biologique en France proviennent avant tout de la rupture conséquente qu'elle introduit en ce qui concerne notre rapport à l'espace. La place de l'agriculteur dans la société est refondée, les paysages tels que nous les entendions sont bouleversés. Il semble bien qu'une nouvelle modernité soit en train de se développer, à côté de tant d'autres il est vrai.

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

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.

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

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.)

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

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)

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)

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

Une nouvelle vision pour AfricaAdapt – Entrevue avec Moussa Na ...

International Development Research Centre (IDRC) Digital Library (Canada)

24 févr. 2011 ... Réseau panafricain lancé en mai 2009, AfricaAdapt vient de recevoir le feu vert pour l'exécution d'une nouvelle phase d'activités de deux ans, qu'appuie le programme Adaptation aux changements climatiques en Afrique.

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

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…

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

IFP Energies nouvelles - 2013 Activity Report. 2013 financial report. Innovating for energy

International Nuclear Information System (INIS)

2014-01-01

IFP Energies nouvelles (IFPEN) is a public research and training player. It has an international scope, covering the fields of energy, transport and the environment. From research to industry, technological innovation is central to all its activities. As part of the public-interest mission with which it has been tasked by the public authorities, IFPEN focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the emergence of a sustainable energy mix; - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. IFPEN has proven expertise across the entire value chain, from fundamental research to industrial research and innovation. It is funded both by a state budget and by resources provided by French and foreign international partners. The aim of IFPEN's R and D programs is to overcome existing scientific and technological barriers in order to develop innovations that can be used by industry. Through its research and resulting innovations, IFPEN fosters the economic development of fields related to the energy, transport and eco-industry sectors. In so doing, it also contributes to creating wealth and jobs. IFPEN's innovations are developed industrially through close partnerships with industrial players and IFP Group subsidiaries. In both emerging and mature markets, IFPEN creates companies or acquires stakeholdings in companies of significant potential, either directly or via capital funds. In addition, IFPEN supports the development of SMEs and SMIs as part of collaboration agreements, contributing its technical and legal expertise. Representing over 50 professions, from geological engineers to power-train engineers, IFPEN's employees form a unique body of globally recognized scientific specialists and an unparalleled network of expertise. In order to carry out their research work at the cutting edge of innovation, they have

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

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)

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

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.

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.

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

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…

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.

Discours rationnel vs discours passionnel. Analyse sémiotique d’un fragment de la Nouvelle Héloïse

Directory of Open Access Journals (Sweden)

Alexandrina Mustăţea

2007-05-01

Full Text Available Roman sentimental, La Nouvelle Héloïse double son parcours narratif d’un parcours émotionnel et sensoriel qui dessine ce que l’on pourrait nommer la configuration passionnelle de l’ensemble textuel. Roman épistolaire, La Nouvelle Héloïse situe le foyer de la passion dans le corps même du scripteur de la lettre, à la fois être du monde sensible et instance discursive.

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

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

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.

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.

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…

Régler les conflits locaux en Amérique latine : de nouvelles ...

International Development Research Centre (IDRC) Digital Library (Canada)

Au cours de la dernière décennie, les conflits locaux se sont répandus dans toute ... conjuguées à de nouvelles façons de concevoir la nature des conflits locaux. ... En partenariat avec l'Organization for Women in Science for the Developing ...

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

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.

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.

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)

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.

Nouvelles de l'Italie sur la linguistique et l'education

Directory of Open Access Journals (Sweden)

Raffaele Simone

1984-12-01

Full Text Available L'auteur donne. des informations sur l'état actuel des débats concernant le développement du langage dans l'école italienne d'aujourd'hui, et prop6se U:ne "nouvelle" notion de linguistique appliquée, considérée en tant que confrontation de systèmes de sens, plutôt de systèmes de formes.

La hernie ombilicale africaine : nouvelle classification et revue de 30 ...

African Journals Online (AJOL)

L'objectif de ce travail était de proposer une nouvelle classification de la hernie ombilicale de l'enfant africain et d'évaluer les résultats du traitement chirurgical.Il s'agit d'une étude prospective portant sur 30 patients porteurs de hernie ombilicale, qui s'est déroulée sur une période de un an et demi dans les services de ...

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).

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.

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

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

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

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

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.

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.

Synthèse, étude toxicologique et activité psychotrope de nouvelles ...

African Journals Online (AJOL)

Hilaire

Pharmacology. Synthèse, étude toxicologique et activité psychotrope de nouvelles arylidènpyridazin-. 3-ones N-substituées. Adnane BENMOUSSA1*, Pascal Manuele KANYONGA2,3, M'Hammed ANSAR1, Amina ZELLOU2, J EL. HARTI1, Jamal LAMSAOURI1, My Abbes FAOUZI2 , Ahmed ZAHIDI1, Hamid BENZIANE1, ...

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

Une nouvelle vision de la transition en Syrie | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Une nouvelle vision de la transition en Syrie. 07 juin 2016. Bénéficiaire : Syrian Center for Political and Strategic Studies (SCPSS) Période visée : de juillet 2012 à août 2013. État : en cours de clôture. Financement accordé : 441 000 CAD. La Coalition nationale syrienne a officiellement donné son aval à une feuille de route ...

Nouvelles et activités | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Restez informé. Soyez au courant des toutes dernières nouvelles au sujet des programmes et des activités du CRDI, de ses réalisations et de celles des chercheurs que nous subventionnons. Apprenez-en plus sur les événements à venir au Canada et dans nos régions ou obtenez des renseignements sur les conférences, ...

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)

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)

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.

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.

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

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

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.

Une Cyathura cavernicole nouvelle de Sarawak – Kalimantan du Nord (Isopoda, Anthuridae)

NARCIS (Netherlands)

Andreev, Stoitze

1982-01-01

A l’occasion d’une expédition spéléologique effectuée en 1978 à Sarawak et organisée par la Royal Geographical Society, le biospéléologue anglais Dr. Ph. Chapman a recueilli quelques exemplaires d’un Isopode des eaux douces souterraines, appartenant à une nouvelle espèce du genre Cyathura. La

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

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.

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)

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

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...

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.)

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

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)

Nouvelles et activités | Page 6 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Jean Lebel, président du CRDI, et Andrew Campbell, premier dirigeant de l'. CRDI. NOUVELLES ACTIVITÉS. Le CDRI renouvelle son partenariat avec ACIAR en matière de sécurité alimentaire. Le CRDI et le Australian Centre for International Agricultural Research, ont conclu un accord en... Vous voulez en savoir plus Le ...

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

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

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

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.

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.

La « nouvelle modernité » urbaine.

Directory of Open Access Journals (Sweden)

Alexis Salanson

2003-01-01

Full Text Available Président du conseil scientifique de l'Institut « Pour la ville en mouvement » et professeur à l'Institut français d'urbanisme (Paris 8, François Ascher résume dans cet ouvrage les thèses qu'il a défendues tout au long de ses précédentes publications 1  : la société dans laquelle nous vivons s'éloigne irrémédiablement de ce qu'elle fut pendant la révolution industrielle pour basculer dans une « nouvelle modernité ». Celle-ci conduit à repenser ...

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.

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

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.

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.

NOUVELLES PERSPECTIVES EN ONCOLOGIE MEDICALE MEDECINE MOLECULAIRE ET SES PERSPECTIVES

Directory of Open Access Journals (Sweden)

Jean-Yves BLAY

2017-05-01

Full Text Available La médecine  moléculaire du cancer  s’appuie sur l’identification d’anomalies génomique de  l’ADN des cellules tumorales, permettant de guider le traitement des patients, en choisissant des inhibiteurs agissant sur les protéines mutées codées par les gènes mutés. Cependant, on assiste depuis 10 ans à l’émergence très rapide d’un nouveau corpus de connaissance décrivant les anomalies génomiques des cellules cancéreuses au sein des programmes internationaux  comme ICGC ou TCGA, permettant de déboucher sur de nouvelles classifications nosologiques mais démontrant aussi l’extrème  complexité et variabilité clonale des cellules cancéreuses  chez le patient humain. Il s’agit désormais d’utiliser ces données  nouvelles de manière  efficace. Ceci requiert la constitution de plateformes de diagnostic  explorant progressivement avec  une plus grande profondeur  les anomalies moléculaire de chaque patient individuel, et l’organisation de réunions de concertation pluridisciplinaires moléculaire permettant d’intégrer ces données au contexte  clinique et global du patient, et requérant la  contribution  croissante des bio-informaticiens. Ce  court article  fait le point  sur l’évolution de cette médecine moléculaire.

DESIGNOR: une méthode nouvelle d'aide à la conception des produits industriels

OpenAIRE

Choffray, Jean-Marie

1980-01-01

Cet article présente une méthode nouvelle, appelée DESIGNOR, d'aide à la décision marketing. Son objectif est d'accroître la créativité au cours du processus de développement d'un nouveau produit industriel et de réduire les risques d'échec commercial.

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)

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.

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.

Geophysical characterization of subsurface barriers

International Nuclear Information System (INIS)

Borns, D.J.

1995-08-01

An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

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

Women Engineers: Factors and Obstacles Related to the Pursuit of a Degree in Engineering

Science.gov (United States)

Wentling, Rose Mary; Camacho, Cristina

Research on women in engineering confirms the presence of gender barriers that affect the recruitment and retention of women in engineering. These barriers stop some women from choosing engineering as a field of study, and impede some women from completing a degree in engineering. However, there are some young female students who complete their engineering education despite the presence of obstacles throughout their college years. This study addressed the factors that have hindered, motivated, and assisted women who graduated with a degree in engineering. By studying and understanding the barriers that hinder women in deciding to pursue and in completing a degree in engineering, as well as the factors that assist and encourage them, we can learn how to break down the barriers and how to facilitate the educational journey of female engineering students. This study provides valuable insights and created a framework from which high schools, universities, researchers, and female students can directly benefit.

Description d’une espèce nouvelle du genre Ectatorhinus (Coleoptera: fam. Curculionidae)

NARCIS (Netherlands)

Roelofs, W.

1890-01-01

Monsieur Neervoort van de Poll ayant reçu récemment avec d’autres insectes une nouvelle espèce d’ Ectatorhinus, capturée dans l’intérieur de Bedagei (Deli, Sumatra orient.) par M. J. Z. Kannegieter, m’a invité de la décrire, ce que je fais avec d’autant plus de plaisir que j’avais décrit dans le

LE SENTIMENT DE LA NATURE DANS LA NOUVELLE HELOISE DE ROUSSEAU

OpenAIRE

YÖNTEN, Yrd.Doç.Dr.Uğur

2002-01-01

Yrd.Doç.Dr.Uğur YÖNTEN D.Ü.Eğitim Fakültesi Fransız Dili Eğitimi A.B.D Bu çalışmamızda Jean-Jacques Rousseau'nun Julie ou La Nouvelle Héloïse (Julie Ya da Yeni Héloïse) adlı romanında "doğa tutkusunu" incelemeye çalıştık. Romandaki doğa yansımalarını ele almadan önce yazardaki bu duygunun nasıl ve ne zam...

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.

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

International Nuclear Information System (INIS)

2010-01-01

The 4. edition of the International Meeting 'Clays in Natural and Engineered Barriers for Radioactive Waste Confinement' took place at the 'Cite Internationale des Congres' of Nantes (France). Approximately 500 participants (from about 20 different countries) attended the meeting. All the abstracts (oral and poster sessions) are included in these proceedings. The purpose of this 4. international conference is to gather specialists in the different disciplines related to clays and clay minerals, with scientists from organisations engaged in radioactive waste disposal, in order to evaluate the progress of the research conducted in that field. Multidisciplinary approaches including geology, mineralogy, geochemistry, rheology, geomechanics of clays are required in order to provide a detailed characterisation 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 disposal facilities. The major objectives for the experimental programs are constituted by the performance evaluation for the natural barrier as well as the impact of repository-induced disturbances upon the confinement properties of clay-rich geological formations. This is being or will be conducted in underground research laboratories, for interpreting the subsequent scientific results, for modelling the long-term behaviour of radioactive waste repositories and for carrying out safety assessment exercises. This conference covers all the aspects of clay characterisation and behaviour relevant to the confinement of radionuclides in clay, considered at various time scales and locations, from the descriptions of basic phenomenological processes to the global understanding of the performance and safety at repository and geological scales. Most of the topics covered by the programme of the conference are in line with the general objectives

Le méga-fichier TES dans une nouvelle architecture de surveillance

OpenAIRE

Vitalis, André

2017-01-01

La récente création du méga-fichier biométrique TES de tous les Français, répond, même s’il n’est pas mis en avant, à un souci sécuritaire. Si l’on veut véritablement comprendre les raisons et la portée de cette création, il faut la replacer dans la nouvelle architecture de surveillance en cours de construction depuis plus d’une décennie.

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

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)

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

LHC 2008 lectures "Une nouvelle vision du monde"

CERN Multimedia

2008-01-01

The history of the science of the Universe and the science of matter have been marked by a small number of "revolutions" that have turned our understanding of the infinitesimally large and the infinitesimally small on its head. New ways of looking at the world have come about sometimes through conceptual advances and sometimes through innovations in scientific instrumentation. How do things stand at the beginning of the 21st century? Will today’s large-scale machine projects like the LHC and gravitational wave detectors pave the way for a new scientific revolution? Thursday, 15 May 2008 at 8.00 p.m. Une nouvelle vision du monde Jean-Pierre Luminet, Research Director at the CNRS The Globe, first floor No specialist knowledge required. Entrance free. To reserve call + 41 (0) 22 767 76 76 http://www.cern.ch/globe

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...

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)

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...

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

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)

Living on the mall : patterning and place making in the case study of Nouvelle

Energy Technology Data Exchange (ETDEWEB)

Gillies-Smith, S.; Ring, H. [Martha Schwartz, Inc., Cambridge, MA (United States)

2007-07-01

One of the largest habitable green roofs in the New England area was designed by Martha Schwartz Inc. The green roof spans 1.5 acres of mall rooftop that will be accessible by two connected condominium towers. A condominium complex associated with the expansion of the Natick Mall entitled Nouvelle, offers a new type of housing, in which a private, residential apartment complex adjoins a suburban, upscale indoor shopping mall. There are many new opportunities to use the expansive area of the mall complex roof to function as a productive, multi-use, shared private park. As an art-based landscape architectural practice, the office has adapted bold and graphic qualities as a model for its green roof design. The Nouvelle green roof offers dynamic circulation, enjoyable social space and recreation, intersecting a continuous coverage of patterned sedum and river stone that spans an entire roofscape. The green roof demonstrates an innovative combination of intensive and extensive plantings that create a system of legible and visually pleasing patterning from above. This case study addressed these innovations and implementation challenges within the context of mall architecture and green roof technologies. In addition, it also identified the social uses of roof spaces, and the aesthetics and sustainability of patterning in intensive and extensive planting design.

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.

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

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

La nouvelle vague in polarized neutron scattering

International Nuclear Information System (INIS)

Mezei, F.

1986-01-01

Polarized neutron research, like many other subjects in neutron scattering developed in the footsteps of Cliff Shull. The classical polarized neutron technique he pioneered was generalized around 1970 to vectorial beam polarizations and this opened up the way to a ''nouvelle vague'' of neutron scattering experiments. In this paper I will first reexamine the old controversy on the question whether the nature of the neutron magnetic moment is that of a microscopic dipole or of an Amperian current loop. The problem is not only of historical interest, but also of relevance to modern applications. This will be followed by a review of the fundamentals on spin coherence effects in neutron beams and scattering, which are the basis of vectorial beam polarization work. As an example of practical importance, paramagnetic scattering will be discussed. The paper concludes with some examples of applications of the vector polarization techniques, such as study of ferromagnetic domains by neutron beam depolarization and Neutron Spin Echo high resolution inelastic spectroscopy. The sample results presented demonstrate the new opportunities this novel approach opened up in neutrons scattering research. (orig.)

Heterogeneous reactions of dioctahedral smectites in illite-smectite and kaolinite-smectite mixed-layers: applications to clay materials for engineered barriers

International Nuclear Information System (INIS)

Meunier, A.; Proust, D.; Beaufort, D.; Lajudie, A.; Petit, J.-C.

1992-01-01

The clay materials selected for use in the engineered barriers of the French nuclear waste isolation programme are mainly composed of dioctahedral smectite, either bentonite of Wyoming type or kaolinite-smectites most often consist of randomly stacked layers with low and high charges. In the case of the Wyoming-type bentonite, these two differently charged layers do not react in the same way when subjected to hydrothermal alteration. Overall, the low-charge smectite layers react to form high-charge smectite layers + quartz + kaolinite. Then, fixing K ions, the high-charge smectite layers are transformed into illite-smectite mixed-layers (I/S) when the temperature conditions increase. A symmetrical process is observed in natural or experimental hydrothermal conditions when the high-charge smectite layers of I/S minerals react with quartz and/or kaolinite to produce low-charge smectite layers. The chemical properties of the bentonite-engineered barriers clearly depend on the low charge/high charge smectite layer proportion, which is in turn controlled by the temperature-dependent reactions in the vicinity of the waste disposal. Although there are fewer published data on the kaolinite-smectite mixed-layered minerals (K/S), a similar low charge-high charge reaction appears to affect their smectite component. The experimental alteration of K/S leads to the formation of a low-charge beidellite with an increase in the cation-exchange capacity and in the expandability of the clay material. Thus, the properties of the engineered barrier seems to be improved after hydrothermal alteration. (Author)

La banque de la Nouvelle-Calédonie. Existence éphémère, expérience oubliée (1874-1877)

OpenAIRE

Buttet, Catherine

2009-01-01

La Nouvelle-Calédonie, colonie pénale peu peuplée, était en 1870 tributaire des commerçants et du Trésor public pour l'ensemble des opérations bancaires. Née d'une société de colonisation d'initiative privée, la Banque de la Nouvelle-Calédonie fut une expérience distincte des anciennes banques coloniales et dont le nouveau cadre statutaire servit ensuite à la Banque d'Indochine. La banque reçut l'aval du gouvernement sous la forme d'une autorisation puis d'un privilège. Rapidement, la banque ...

Appliance of geochemical engineering in radioactive waste disposal

International Nuclear Information System (INIS)

Li Shuang; Zhang Chengjiang; Ni Shijun; Li Kuanliang

2008-01-01

The basic foundation of applying geochemical engineering to control environment, common engineering models of disposal radioactive waste and the functions of the engineering barriers are introduced in this paper. The authors take the geochemical engineering barrier materiel research of a radioactive waste repository as an example to explain the appliance of geochemical engineering in the disposal of radioactive waste. And the results show that it can enhance the security of the nuclear waste repository if we use geochemical engineering barrier. (authors)

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.

La nouvelle bourgeoisie islamique. Le modèle turc, de Dilek Yankaya

OpenAIRE

Lelandais, Gülçin Erdi

2016-01-01

De nombreux travaux sur la Turquie contemporaine ont été réalisés ces dernières années en France. La plus grande partie d’entre eux se focalise sur le champ politique et ses évolutions, les minorités ethniques — notamment les Kurdes –, et sur des mobilisations sociales, politiques et environnementales comme la mobilisation autour du parc Gezi. Le livre de Dilek Yankaya ouvre un nouveau champ d’analyse avec sa recherche, pionnière en son genre en France, qui étudie l’émergence d’une nouvelle é...

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.

Transcytosis in the blood–cerebrospinal fluid barrier of the mouse brain with an engineered receptor/ligand system

Directory of Open Access Journals (Sweden)

Héctor R Méndez-Gómez

Full Text Available Crossing the blood–brain and the blood–cerebrospinal fluid barriers (BCSFB is one of the fundamental challenges in the development of new therapeutic molecules for brain disorders because these barriers prevent entry of most drugs from the blood into the brain. However, some large molecules, like the protein transferrin, cross these barriers using a specific receptor that transports them into the brain. Based on this mechanism, we engineered a receptor/ligand system to overcome the brain barriers by combining the human transferrin receptor with the cohesin domain from Clostridium thermocellum, and we tested the hybrid receptor in the choroid plexus of the mouse brain with a dockerin ligand. By expressing our receptor in choroidal ependymocytes, which are part of the BCSFB, we found that our systemically administrated ligand was able to bind to the receptor and accumulate in ependymocytes, where some of the ligand was transported from the blood side to the brain side.

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)

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...

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.

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

Diesel and gas engines: evolution following new regulations; Moteurs diesel et gaz: evolution face aux nouvelles reglementations

Energy Technology Data Exchange (ETDEWEB)

Deverat, Ph. [Bergerat Monnoyeur (France). Direction Industrie

1997-12-31

Engine emissions of CO, NMHC and ashes are easily lowered through a low-cost exhaust gas processing, while NOx processing in fumes is rather complex and environmentally hazardous; thus, engine manufacturers have emphasized their researches for NOx decrease on the engine design: lower combustion temperature in diesel engines through water cooling or air/air exchanger, lean mixture with excess air (open chamber or pre-chamber) in spark ignition gas engines. Examples of modifications in Caterpillar engines are given. Exhaust gas processing for CO, NMHC, NOx (3 way catalytic purifier, selective catalytic reduction) and ashes is also discussed

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

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)

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.

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)

Evaluation of Erosion Resistance of Advanced Turbine Thermal Barrier Coatings

Science.gov (United States)

Zhu, Dongming; Kuczmarski, Maria A.; Miller, Robert A.; Cuy, Michael D.

2007-01-01

The erosion resistant turbine thermal barrier coating system is critical to aircraft engine performance and durability. By demonstrating advanced turbine material testing capabilities, we will be able to facilitate the critical turbine coating and subcomponent development and help establish advanced erosion-resistant turbine airfoil thermal barrier coatings design tools. The objective of this work is to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and/or thermal gradient environments, validating advanced turbine airfoil thermal barrier coating systems based on nano-tetragonal phase toughening design approaches.

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

Armored Geomembrane Cover Engineering

Directory of Open Access Journals (Sweden)

Kevin Foye

2011-06-01

Full Text Available Geomembranes are an important component of modern engineered barriers to prevent the infiltration of stormwater and runoff into contaminated soil and rock as well as waste containment facilities—a function generally described as a geomembrane cover. This paper presents a case history involving a novel implementation of a geomembrane cover system. Due to this novelty, the design engineers needed to assemble from disparate sources the design criteria for the engineering of the cover. This paper discusses the design methodologies assembled by the engineering team. This information will aid engineers designing similar cover systems as well as environmental and public health professionals selecting site improvements that involve infiltration barriers.

The Function of the Medieval in Jean-Jacques Rousseau's Nouvelle Heloise : A Rereading of the Abelard and Heloise Motif

NARCIS (Netherlands)

Montoya, Alicia C.

2010-01-01

Jean-Jacques Rousseau's critical rewriting in his Nouvelle H,lo

Qui sera le nouvel Einstein ? Vers une nouvelle theorie de la gravitation

Science.gov (United States)

Bonnet-Bidaud, J. M.

1999-10-01

Un debat de plus d'un siecle a resurgi ces toutes dernieres annees avec une vigueur nouvelle. L'enjeu ? Mettre fin, ni plus ni moins, a l'une des contradictions les plus inouies de la physique fondamentale, en reconciliant mecanique quantique et relativite generale. En effet, a l'heure ou la gravitation semble enfin sur le point de fusionner avec les trois autres forces de la nature. il est certain que la relativite d'Einstein doit etre bientot remplacer par une autre theorie... Reste quye tous les physiciens sont loin de s'accorder sur la marche a suivree. Gravitation quantique, relativite d'echelle, supersymetrie, les candidates ne manquent pas.

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.

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)

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

Adiabatic Wankel type rotary engine

Science.gov (United States)

Kamo, R.; Badgley, P.; Doup, D.

1988-01-01

This SBIR Phase program accomplished the objective of advancing the technology of the Wankel type rotary engine for aircraft applications through the use of adiabatic engine technology. Based on the results of this program, technology is in place to provide a rotor and side and intermediate housings with thermal barrier coatings. A detailed cycle analysis of the NASA 1007R Direct Injection Stratified Charge (DISC) rotary engine was performed which concluded that applying thermal barrier coatings to the rotor should be successful and that it was unlikely that the rotor housing could be successfully run with thermal barrier coatings as the thermal stresses were extensive.

L’hybridation interspécifique chez les champignons phytopathogènes à l’origine de nouvelles maladies

OpenAIRE

Frey, Pascal

2009-01-01

Mécanisme évolutif bien connu chez les plantes, l’hybridation interspécifique a été relativement peu étudiée dans certains groupes taxonomiques, comme les champignons. Chez les champignons phytopathogènes, l’hybridation entre une espèce indigène et une espèce exotique peut pourtant conduire à l’émergence de nouvelles maladies des plantes.

10 CFR 63.115 - Requirements for multiple barriers.

Science.gov (United States)

2010-01-01

... Requirements for multiple barriers. Demonstration of compliance with § 63.113(a) must: (a) Identify those design features of the engineered barrier system, and natural features of the geologic setting, that are... 10 Energy 2 2010-01-01 2010-01-01 false Requirements for multiple barriers. 63.115 Section 63.115...

Women in Engineering: The Impact of the College Internship on Persistence into an Engineering Field

Science.gov (United States)

Brush, Kimberly M.

2013-01-01

The development of a diverse engineering workforce, with a variety of skills and interests is essential to the future of American innovation. Historically, the engineering field has been grounded in a series of standards that often benefit men while creating barriers for women. Thus, strategies for overcoming barriers to women's successful…

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.

Fostering Creative Engineers

DEFF Research Database (Denmark)

Zhou, Chunfang

2012-01-01

. As the literature demonstrates, this paper reveals the understanding of complexity in engineering practice and the roles of creativity in engineering practice. In addition, the barriers to creativity in current engineering education and some implications of pedagogic strategies will be discussed. So this paper...

Near-field geologic environment as an effective barrier against radionuclide transport

International Nuclear Information System (INIS)

Umeki, H.; Sakuma, H.; Ishiguro, K.; Hatanaka, K.; Naito, M.

1993-01-01

A generic performance assessment of the geologic disposal system of HLW in Japan has been carried out by the Power Reactor and Nuclear Fuel Development Corporation (PNC) in accordance with the overall HLW management program defined by the Japanese Atomic Energy Commission. A massive engineered barrier system, consisting of vitrified waste, carbon-steel overpack and thick bentonite buffer, is introduced to ensure a long-term performance of the disposal system considering a wide range of geologic environment. A major part of the total performance of the disposal system is borne by the engineered barrier system given a geologic environment that assures and complements the performance of such engineered barrier system. The performance of the natural barrier system coupled with the strong engineered barrier system was investigated by sensitivity analyses. Two types of conceptual model were considered for the analysis to describe radionuclide transport in geologic media and the range of relevant parameters was given by taking the variation of the geologic environment in Japan into account. The results show that the degree of retardation of radionuclide transport chosen in the geologic media varies significantly depending on the parameter values chosen. However, it is indicated that there are realistic combinations of those geologic parameter values which could provide a sufficient degree of retardation within a range of only a few tens of meters from the engineered barrier system. The relative importance of the near-field geologic environment is also discussed

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

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

The Development of Environmental Barrier Coatings for SiCSiC Ceramic Matrix Composites: Challenges and Opportunities

Science.gov (United States)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned CMC components to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing advanced environmental barrier coating systems, the coating integrations with next generation CMC turbine components having improved environmental stability, cyclic durability and system performance will be described. The development trends for turbine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

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

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

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

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.

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

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.

Investigations of thermal barrier coatings of turbine parts using gas flame heating

Science.gov (United States)

Lepeshkin, A. R.; Bichkov, N. G.; Ilinskaja, O. I.; Nazarov, V. V.

2017-09-01

The development of methods for the calculated and experimental investigations thermal barrier coatings and thermal state of gas-turbine engine parts with a thermal barrier coatings is actual work. The gas flame heating was demonstrated to be effectively used during investigations of a thermal ceramic barrier coatings and thermal state of such gas-turbine engine parts with a TBC as the cooled turbine blades and vanes and combustion liner components. The gas-flame heating is considered to be preferable when investigating the gas-turbine engine parts with a TBC in the special cases when both the convective and radiant components of thermal flow are of great importance. The small-size rig with gas-flame flow made it possible to conduct the comparison investigations with the purpose of evaluating the efficiency of thermal protection of the ceramic deposited thermal barrier coatings on APS and EB techniques. The developed design-experiment method was introduced in bench tests of turbine blades and combustion liner components of gas turbine engines.

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...

Crenicichla tigrina, Une nouvelle espèce de cichlidae (Pisces, Perciformes) du Rio Trombetas, Pará, Brésil

NARCIS (Netherlands)

Ploeg, Alex; Jégu, Michael; Ferreira, Efrem

1991-01-01

Une nouvelle espèce de Cichlidae, Crenicichla tigrina, est décrite et illustrée. La coloration sur le vivant et quelques remarques relatives à l’Pecologie de cette espèce sont présentée. Les relations de C. tigrina avec les autres espèces de Crenicichla à petites écailles et le mode de distribution

Entre Classicisme et Modernité : La Nouvelle Revue Française dans le champ littéraire de la Belle Epoque

NARCIS (Netherlands)

Koffeman-Bijman, M.N.

2003-01-01

The literary review La Nouvelle Revue Française enjoys an enormous prestige in France. In Entre Classicisme et Modernité, Maaike Koffeman explores the origins of this legend of French literary life by means of a historical, literary and sociological analysis of the first years of the review s

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.

Karl Polanyi, la Nouvelle sociologie économique et les forces du marché

Directory of Open Access Journals (Sweden)

Ronan Le Velly

2008-12-01

Full Text Available Cet article montre en quoi plusieurs auteurs de la Nouvelle sociologie économique tendent à adopter un regard incomplet sur les forces du marché. Pour cela, l’auteur distingue deux notions d’encastrement renvoyant pour la première à un cadre méthodologique institutionnaliste et pour la seconde à l’observation du poids variable des forces du marché. Il établit qu’autant des sociologues classiques comme Weber ou Polanyi ont su coupler ces deux approches, autant plusieurs travaux majeurs de la Nouvelle sociologie économique, notamment ceux de Zelizer, de Fligstein et de Biggart, adoptent la première perspective mais ne traitent que de façon partielle de la seconde. L’auteur met particulièrement en cause les objets de recherche retenus par ces derniers auteurs, dès lors que sont systématiquement privilégiées des situations où les forces du marché sont tenues à l’écart.This article shows how many authors of the New Economic Sociology tend to adopt an incomplete view of market forces. The author distinguishes two notions of embeddedness, one related to the institutionalist theories and the second to the observation of the variable weight of market forces. It is established that classical sociologists such as Weber or Polanyi have joined these two approaches, while manyu works of the New sociological economy, for examle those of Zelizer, Fligstein or Biggart adopt the first perspective, but only treat the second partially. The author particularly questions the research objects chosen by these authors, since he considers that they generally refer to situations where market forces are held at bay.

La nouvelle donne de la santé globale : dynamiques et écueils

Directory of Open Access Journals (Sweden)

Marine Buissonnière

2012-04-01

Full Text Available Les quinze dernières années ont été marquées par l’avènement de nouveaux acteurs dans le champ de la santé globale et l’augmentation de l’aide au développement en faveur de la santé. Ces acteurs ont capté une partie importante des ressources privées et publiques supplémentaires disponibles et se sont imposés comme les pièces maîtresses de ce nouvel échiquier, aux dépens des institutions traditionnelles qui ont graduellement perdu leur prépondérance et ont vu leur leadership s’affaiblir. Les choix et politiques de santé ont peu à peu échappé à la seule autorité des institutions qui en avaient jusqu’alors le mandat et en assumaient la charge. Certains pans entiers de la santé sont désormais dominés par des financeurs privés, devenus de facto prescripteurs d’orientations de santé publique. Cette nouvelle donne pose des questions essentielles de gouvernance et de responsabilité. Qui décide des orientations ? Comment les décisions sont-elles prises ? Les pays destinataires de l’aide doivent encore trop souvent subir le manque de coordination des donateurs et l’absence d’alignement des agendas. Dans ce contexte, et en prenant acte de cette nouvelle réalité, quelques pistes mériteraient d’être explorées afin de garantir que les orientations en matière de santé globale reflètent au mieux la réalité des besoins et les aspirations des pays.

Bond strength and stress measurements in thermal barrier coatings

Energy Technology Data Exchange (ETDEWEB)

Gell, M.; Jordan, E. [Univ. of Connecticut, Storrs, CT (United States)

1995-10-01

Thermal barrier coatings have been used extensively in aircraft gas turbines for more than 15 years to insulate combustors and turbine vanes from the hot gas stream. Plasma sprayed thermal barrier coatings (TBCs) provide metal temperature reductions as much as 300{degrees}F, with improvements in durability of two times or more being achieved. The introduction of TBCs deposited by electron beam physical vapor deposition (EB-PVD) processes in the last five years has provided a major improvement in durability and also enabled TBCs to be applied to turbine blades for improved engine performance. To meet the aggressive Advanced Turbine Systems goals for efficiency, durability and the environment, it will be necessary to employ thermal barrier coatings on turbine airfoils and other hot section components. For The successful application of TBCs to ATS engines with 2600{degrees}F turbine inlet temperatures and required component lives 10 times greater than those for aircraft gas turbine engines, it is necessary to develop quantitative assessment techniques for TBC coating integrity with time and cycles in ATS engines. Thermal barrier coatings in production today consist of a metallic bond coat, such as an MCrAlY overlay coating or a platinum aluminide (Pt-Al) diffusion coating. During heat treatment, both these coatings form a thin, tightly adherent alumina (Al{sub 2}O{sub 3}) film. Failure of TBC coatings in engine service occurs by spallation of the ceramic coating at or near the bond coat to alumina or the alumina to zirconia bonds. Thus, it is the initial strength of these bonds and the stresses at the bond plane, and their changes with engine exposure, that determines coating durability. The purpose of this program is to provide, for the first time, a quantitative assessment of TBC bond strength and bond plane stresses as a function of engine time and cycles.

Diesel and gas engines: evolution facing new regulations; Moteurs diesel et gaz: evolution face aux nouvelles reglementations

Energy Technology Data Exchange (ETDEWEB)

Daverat, Ph. [Bergetat Monnoyeur (France)

1997-12-31

This paper analyzes the influence of new pollution regulations on the new design of diesel and gas engines with the example of Caterpillar`s experience, one of the leaders of diesel and gas engines manufacturers worldwide. The technical problems to solve are introduced first (reduction of NO{sub x}, SO{sub 2}, CO, unburned compounds and dusts), and then the evolution of engines and of exhaust gas treatment systems are described (fuel injection systems, combustion and ignition control, sensors, catalytic conversion and filtering systems). (J.S.)

How the Nouvelle Vague Invented the DVD: Cinephilia, new waves and film culture in the age of digital dissemination

Directory of Open Access Journals (Sweden)

Malte Hagener

2014-01-01

Full Text Available Whereas the currently emerging configurations of audiovisualcy in the age of digital networks are often addressed in terms of absolute novelty and innovation, this article wishes to shift the focus slightly, articulating instead the new in terms of the old. This essay proposes the argument that it was within the Nouvelle Vague and the French film culture of the 1960s that the DVD was “invented”. Obviously, this is a contrafactual argument, but if we understand the DVD as a discursive construction articulating a specific perspective on film, then the DVD simulates and emulates some key features of 1960s cinephilia that emerged within the context of the new waves. On the other hand, the Nouvelle Vague is understood as a broad discursive movement encompassing all segments of the institution cinema rather than five auteur-directors — Truffaut, Godard, Chabrol, Rohmer and Rivette — and their respective films. By arguing for the continuing importance of film history and culture, this article wishes to underline the fact that technological as well as aesthetic transformations are central to our understanding of media culture.

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

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

Le programme ARTEMIS : nouvel outil pour la datation radiocarbone AMS (Spectromètre de Masse par Accélérateur et nouvelles problématiques

Directory of Open Access Journals (Sweden)

Cyrille Billard

2012-04-01

Full Text Available La mise en route du nouvel équipement ARTEMIS (Accélérateur pour la Recherche en sciences de la Terre, Environnement, Muséologie, Implanté à Saclay à partir de 2004 ouvre de nouvelles perspectives scientifiques et conduit à de nouvelles procédures de soumission des échantillons destinés à une datation 14C. Le MCC dispose aujourd’hui de droits alloués aux services régionaux de l'archéologie, services du ministère de la Culture, confrontés à ce type de demandes (musées, monuments historiques. Il impose désormais une nouvelle démarche de programmation scientifique des datations, associant une analyse critique des demandes.Since 2004, the availability at Saclay of a new ARTEMIS installation (Accélérateur pour la Recherche en sciences de la Terre, Environnement, Muséologie has opened new scientific perspectives and led to new procedures for submitting samples for carbon-14 dating. The French Ministry of Culture has the possibility of using this tool for radiocarbon dating at the request of its regional archaeological services or other services, such as museums and the historic monuments administration. This use now implies a new approach to the scientific planning for dating problems, associated with a critical analysis of the requests.

Relation de service, rapport social de service : Quelle grille d’analyse ? Analysing service relationships and service-based social relationships. Debate with the editors of the Nouvelle Revue du Travail Relación de servicio, vínculo social de servicio: ¿qué modelo analítico? Debate con la redacción de la Nouvelle Revue du Travail

Directory of Open Access Journals (Sweden)

Guillaume Tiffon

2013-03-01

Full Text Available Dans un échange avec la Nouvelle Revue du Travail, Pascal Ughetto et Philippe Zarifian prolongent la controverse sur les grilles d’analyse des services, en discutant les pré-requis sur lesquels reposent leurs postures respectives. Ce débat fait suite à leurs contributions dans le dossier Controverses de ce numéro « Relation de service, rapport social de service. Quelle grille d’analyse ? »In a conversation with the Nouvelle Revue du Travail, Pascal Ughetto and Philippe Zarifian address the controversy about service-related analytical grids, by focusing on the preconditions underlying each grid’s particular orientation. The debate follows their contributions to the Controverses special section found in a special issue called “Analysing service relationships and service-based social relationships”En una conversación con la Nouvelle Revue du Travail, Pascal Ughetto y Philippe Zarifian prolongan la controversia sobre los modelos analíticos de los servicios, debatiendo sobre los prerrequisitos en los cuales se apoyan sus respectivas posturas. Ese debate ha surgido tras sus contribuciones al número especial Controverses de esta edición “Relación de servicio, vínculo social de servicio. ¿Qué modelo analítico ?

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.

Crack formation in cementitious materials used for an engineering barrier system and their impact on hydraulic conductivity from the viewpoint of performance assessment of a TRU waste disposal system

International Nuclear Information System (INIS)

Hirano, Fumio; Mihara, Morihiro; Honda, Akira; Otani, Yoshiteru; Kyokawa, Hiroyuki; Shimizu, Hiroyuki

2016-01-01

The mechanical analysis code MACBECE2014 has been developed at the Japan Atomic Energy Agency (JAEA) to make realistic simulations of the physical integrity of the near field for performance assessment of the geological disposal of TRU waste in Japan. The MACBECE2014 code can be used to evaluate long-term changes in the mechanical behavior of the near field and any subsequent changes in the permeability of engineering barrier components, including crack formation in cementitious materials caused by expansion due to metal corrosion. Cracks in cementitious materials are likely to channel the flow of groundwater and so the represent preferred flow paths of any released radionuclides. Mechanical analysis was conducted using the MACBECE2014 code to investigate the concept of the TRU waste disposal system described in JAEA's Second Progress TRU Report. Simulated results of a disposal system with a bentonite buffer demonstrated that the low permeability of the engineering barrier system could be maintained for long time periods because the physical integrity of the bentonite buffer remained intact even if cracks in the cementitious components had formed locally. Simulated results of the disposal system with a concrete backfill instead of a bentonite buffer showed that crack formation leads to a significant increase in the permeability of the engineering barrier system. (author)

Une Nouvelle Orientation Psychophysique dans la Pédagogie Théâtrale Contemporaine

Directory of Open Access Journals (Sweden)

Vezio Ruggieri

2015-09-01

Full Text Available Cet article a pour but de présenter comment les apports du modèle psychophysiologique bio-existentialiste élaboré par Vezio Ruggieri et ses collaborateurs peuvent jeter une lumière nouvelle sur les processus sous-jacents le jeu de l’acteur tels que la présence scénique, le processus d’identification avec un personnage et le complexe mécanisme de la prosodie. Cet encadrement théorique, qui voit le rapport corps-esprit dans une relation circulaire, éclairera le lecteur sur les bases physiologiques de la perception et de l’imagination ainsi que sur le rôle fondamental que la structure musculaire joue dans la construction de ces phénomènes.

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.

Prototype Hanford Surface Barrier: Design basis document

International Nuclear Information System (INIS)

Myers, D.R.; Duranceau, D.A.

1994-11-01

The Hanford Site Surface Barrier Development Program (BDP) was organized in 1985 to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site and other arid sites. This document provides the basis of the prototype barrier. Engineers and scientists have momentarily frozen evolving barrier designs and incorporated the latest findings from BDP tasks. The design and construction of the prototype barrier has required that all of the various components of the barrier be brought together into an integrated system. This integration is particularly important because some of the components of the protective barreir have been developed independently of other barreir components. This document serves as the baseline by which future modifications or other barrier designs can be compared. Also, this document contains the minutes of meeting convened during the definitive design process in which critical decisions affecting the prototype barrier's design were made and the construction drawings

Analysis and test of insulated components for rotary engine

Science.gov (United States)

Badgley, Patrick R.; Doup, Douglas; Kamo, Roy

1989-01-01

The direct-injection stratified-charge (DISC) rotary engine, while attractive for aviation applications due to its light weight, multifuel capability, and potentially low fuel consumption, has until now required a bulky and heavy liquid-cooling system. NASA-Lewis has undertaken the development of a cooling system-obviating, thermodynamically superior adiabatic rotary engine employing state-of-the-art thermal barrier coatings to thermally insulate engine components. The thermal barrier coating material for the cast aluminum, stainless steel, and ductile cast iron components was plasma-sprayed zirconia. DISC engine tests indicate effective thermal barrier-based heat loss reduction, but call for superior coefficient-of-thermal-expansion matching of materials and better tribological properties in the coatings used.

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.

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

'Grenelle de l'environnement ' : peut-on se passer d'une nouvelle fiscalité écologique ?

OpenAIRE

Eloi Laurent; Jacques Le Cacheux

2007-01-01

Contrairement à ce qu'a affirmé Al Gore quand il a appris la nouvelle de son Prix Nobel de la paix, la lutte contre le changement climatique n'est pas avant tout une affaire morale, mais bien un enjeu politique, et plus précisément d'économie politique. C'est le problème des moyens, des instruments et des incitations que doit désormais poser et résoudre l'action publique, les travaux des lauréats du " Prix Nobel d'économie " pouvant d'ailleurs se révéler fort utiles dans cette optique pratiqu...

La catalyse d'épuration des gaz d'échappement automobiles. Situation actuelle et nouvelles orientations Catalytic Automotive Exhaust Gas Depollution. Present Status and New Trends

Directory of Open Access Journals (Sweden)

Prigent M.

2006-11-01

Full Text Available Cet article passe en revue les différents systèmes catalytiques de post-traitement utilisés actuellement sur la plupart des automobiles pour limiter leurs rejets de polluants. Les systèmes sont différenciés par leur mode de fonctionnement, le type de moteur à dépolluer (deux-temps, quatre-temps, diesel ou essence ou par leur mode de réalisation. Les nouvelles orientations, prévues pour respecter les futures réglementations antipollution, sont également décrites. On montre que certains véhicules prototypes, équipés de moteurs à combustion interne, sont capables d'avoir des émissions très proches de zéro tout comme les véhicules électriques. A review is made of the various types of exhaust gas aftertreatment systems presently used on most vehicles to reduce pollutant emissions. The systems are differentiated by their mode of action, according to the engine type to be depolluted (two-stroke, four-stroke, diesel or spark-ignition, and by their type of make-up. The major developments foreseen in the future, in view of compliance with the new legislations, are described. It is shown that some prototype vehicles with internal combustion engines are able to emit pollutant quantities really close to zero, such as electric cars.

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

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)

IFP Energies nouvelles. 2016 Activity Report - Innovating for energy

International Nuclear Information System (INIS)

2017-01-01

IFP Energies Nouvelles is a major research and training player in the fields of energy, transport and the environment. From research to industry, technological innovation is central to all its activities, structured around three strategic priorities: sustainable mobility, new energies and responsible oil and gas. As part of the public-interest mission with which it has been tasked by the public authorities, IFPEN focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the transition towards sustainable mobility and the emergence of a more diversified energy mix; - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. An integral part of IFPEN, its graduate engineering school - IFP School - prepares future generations to take up these challenges. IFPEN has proven expertise across the entire value chain, from fundamental research to innovation. It is funded both by a state budget and by its own resources provided by industrial partners. The latter account for over 50% of IFPEN's total budget, a configuration that is quasi unique in France. The aim of IFPEN's R and I programs is to overcome existing scientific and technological challenges in order to develop innovations that can be used by industry. IFPEN's fundamental research program aims to create a bedrock of knowledge essential for the development of innovations. The scientific expertise of IFPEN's researchers is internationally recognized and they are regularly consulted by the public authorities to provide their insight in their specific fields to inform the decision-making process. IFPEN's economic model is based on the transfer to industry of the technologies developed by its researchers. This technology transfer to industry generates jobs and business, fostering the economic development of fields and approaches related to the mobility, energy and eco-industry sectors

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

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...

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)

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)

Finite-element model evaluation of barrier configurations to reduce infiltration into waste-disposal structures: preliminary results and design considerations

International Nuclear Information System (INIS)

Lu, A.H.; Phillips, S.J.; Adams, M.R.

1982-09-01

Barriers to reduce infiltration into waste burial disposal structures (trenches, pits, etc.) may be required to provide adequate waste confinement. The preliminary engineering design of these barriers should consider interrelated barrier performance factors. This paper summarizes preliminary computer simulation activities to further engineering barrier design efforts. Several barrier configurations were conceived and evaluated. Models were simulated for each barrier configuration using a finite element computer code. Results of this preliminary evaluation indicate that barrier configurations, depending on their morphology and materials, may significantly influence infiltration, flux, drainage, and storage of water through and within waste disposal structures. 9 figures

The Development of 2700-3000 F Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites: Challenges and Opportunities

Science.gov (United States)

Zhu, Dongming

2015-01-01

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is a key to enable the applications of the envisioned 2700-3000F EBC - CMC systems to help achieve next generation engine performance and durability goals. This paper will primarily address the performance requirements and design considerations of environmental barrier coatings for turbine engine applications. The emphasis is placed on current NASA candidate environmental barrier coating systems for SiCSiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. The efforts have been also directed to developing prime-reliant, self-healing 2700F EBC bond coat; and high stability, lower thermal conductivity, and durable EBC top coats. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, cyclic durability, erosion-impact resistance, and long-term system performance will be described. The research and development opportunities for turbine engine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be discussed.

Use of engineered soils and other site modifications for low-level radioactive waste disposal

International Nuclear Information System (INIS)

1994-08-01

The U.S. Nuclear Regulatory Commission requires that low-level radioactive waste (LLW) disposal facilities be designed to minimize contact between waste and infiltrating water through the use of site design features. The purpose of this investigation is to identify engineered barriers and evaluate their ability to enhance the long-term performance of an LLW disposal facility. Previously used barriers such as concrete overpacks, vaults, backfill, and engineered soil covers, are evaluated as well as state-of-the-art barriers, including an engineered sorptive soil layer underlying a facility and an advanced design soil cover incorporating a double-capillary layer. The purpose of this investigation is also to provide information in incorporating or excluding specific engineered barriers as part of new disposal facility designs. Evaluations are performed using performance assessment modeling techniques. A generic reference disposal facility design is used as a baseline for comparing the improvements in long-term performance offered by designs incorporating engineered barriers in generic and humid environments. These evaluations simulate water infiltration through the facility, waste leaching, radionuclide transport through the facility, and decay and ingrowth. They also calculate a maximum (peak annual) dose for each disposal system design. A relative dose reduction factor is calculated for each design evaluated. The results of this investigation are presented for concrete overpacks, concrete vaults, sorptive backfill, sorptive engineered soil underlying the facility, and sloped engineered soil covers using a single-capillary barrier and a double-capillary barrier. Designs using combinations of barriers are also evaluated. These designs include a vault plus overpacks, sorptive backfill plus overpacks, and overpack with vault plus sorptive backfill, underlying sorptive soil, and engineered soil cover

COMPASS: A source term code for investigating capillary barrier performance

International Nuclear Information System (INIS)

Zhou, Wei; Apted, J.J.

1996-01-01

A computer code COMPASS based on compartment model approach is developed to calculate the near-field source term of the High-Level-Waste repository under unsaturated conditions. COMPASS is applied to evaluate the expected performance of Richard's (capillary) barriers as backfills to divert infiltrating groundwater at Yucca Mountain. Comparing the release rates of four typical nuclides with and without the Richard's barrier, it is shown that the Richard's barrier significantly decreases the peak release rates from the Engineered-Barrier-System (EBS) into the host rock

Effect of translucence of engineering ceramics on heat transfer in diesel engines

Energy Technology Data Exchange (ETDEWEB)

Wahiduzzaman, S.; Morel, T. (Integral Technologies, Inc., Westmont, IL (United States))

1992-04-01

This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.

O inventário das curiosidades botânicas da Nouvelle France de Pierre-François-Xavier de Charlevoix (1744 The inventory of botanical curiosities in Pierre-François-Xavier de Charlevoix's Nouvelle France (1744

Directory of Open Access Journals (Sweden)

Michel Kobelinski

2013-03-01

Full Text Available Verifica a extensão dos aportes botânicos de Pierre-François-Xavier de Charlevoix em Histoire et description générale de la Nouvelle France em relação a trabalhos de pesquisadores anteriores, suas valorações das representações iconográficas e discursivas e aplicabilidade no projeto de colonização francesa. Investiga-se o que o levou a preterir o modelo taxionômico de Lineu e o que pretendia com seu catálogo de curiosidades botânicas. O desenlace de sua trajetória filosófico-religiosa permite compreender seu posicionamento no quadro de classificação da natureza, os sentidos das informações etnológicas, as formas de apropriação intelectual e os usos da iconografia botânica e do discurso como propaganda político-emotiva para incentivar a ocupação colonial.The article explores the botanical contributions of Pierre-François-Xavier de Charlevoix's book Histoire et description générale de la Nouvelle France vis-à-vis the contributions of previous researchers, his use of iconographic and discursive representations and its relevance to the project of French colonization. It investigates why he refused Linnaeus' taxonomic model and what he intended with his catalogue of botanical curiosities. The unfolding of his philosophical and religious trajectory allows to understand his stance regarding the classification of nature, the meanings of ethnological information, his forms of intellectual appropriation, and his use of discourse and botanical iconography as political and emotional propaganda to encourage colonial settlement.

Nouvelle procédure pour l'augmentation du temps d'usinage simulé en coupe orthogonale

OpenAIRE

Guediche , Mayssa; Mabrouki , Tarek; Donnet , Christophe; Bergheau , Jean-Michel; Hamdi , Hedi

2015-01-01

International audience; Cette étude présente une nouvelle méthodologie visant à augmenter le temps d'usinage simulé en coupe orthogonale .Le but est d'étudier ultérieurement l'évolution de l'usure des outils de coupe dans le cas de l'usinage de l'acier 42CD4. Un modèle lagrangien est donc développé sous le code de calcul ABAQUS simulant la formation du copeau. Une approche baptisée de « modélisation verticale » est développée dans le but d'augmenter le temps de coupe simulé tout en gardant un...

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

Nouvelle méthodologie de synthèse de molécules à potentiel diurétique

OpenAIRE

Ouellet, Simon

2007-01-01

[Synthèse combinatoire ]. Le présent mémoire propose l'élaboration d'une nouvelle méthodologie de synthèse de molécules ayant un potentiel diurétique, et ciblant plus particulièrement les cotransporteurs cations-chlorures, responsables du mouvement couplé des ions sodium et/ou potassium avec celui du chlorure dans plusieurs types de cellules dont celles des néphrons. La première partie est consacrée à une description de la chimie combinatoire, aux travaux antérieurs effectués dans notre la...

Le télé-achat : finalité ou usage par défaut des nouvelles convergences ?

OpenAIRE

Lenoir , Christophe

2000-01-01

HAL : hal-00558853; International audience; Le télé-achat relève-t-il d'une finalité ou d'un usage par défaut des nouvelles convergences ? A partir des questions de détermination technologique et d'indétermination des usages, cet article propose, au vu de l'évolution économique du secteur et de l'information économique véhiculée par ses agents, de s'interroger sur les conditions énonciatives de ces processus de communication et leurs conséquences sur le médium télévisuel.

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

Hanford Site Permanent Isolation Surface Barrier Development Program: Fiscal year 1992 and 1993 highlights

International Nuclear Information System (INIS)

Cadwell, L.L.; Link, S.O.; Gee, G.W.

1993-09-01

The Hanford Site Permanent Isolation Surface Barrier Development Program was jointly developed by the Pacific Northwest Laboratory and Westinghouse Hanford Company to design and test an earthen cover system that can be used to inhibit water infiltration; plant, animal, and human intrusion; and wind and water erosion. Kaiser Engineers Hanford Company provided engineering design support for the program. Work on barrier design has been under way at Hanford for nearly 10 years. The comprehensive development of a long-term barrier, formerly the Hanford Site Protective Barrier Development Program, was initiated in FY 1986, and a general field-tested design is expected to be completed by FY 1998. Highlights of efforts in FY 1992 and FY 1993 included the resumption of field testing, the completion of the prototype barrier design, and the convening of an external peer review panel, which met twice with the barrier development team. The review panel provided helpful guidance on current and future barrier development activities, while commending the program for its significant technical contributions to innovative barrier technology development

Selection of barrier metals for a waste package in tuff

International Nuclear Information System (INIS)

Russell, E.W.; McCright, R.D.; O'Neal, W.C.

1983-09-01

The Nevada Nuclear Waste Storage Investigation (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. LLNL is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. The selection of metal containment barriers is addressed. 13 references

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)

Permeable reactive barriers for pollutant removal from groundwater

International Nuclear Information System (INIS)

Simon, F.G.; Meggyes, T.

2001-01-01

The removal of pollutants from the groundwater using permeable reactive barriers is a novel in-situ groundwater remediation technology. The most relevant decontamination processes used are chemical reduction, oxidation, precipitation and sorption, for which examples are given. Some common organic pollutants are halogenated hydrocarbons, aromatic and nitroaromatic compounds which can be treated in reactive barriers successfully. Lead, chromium and, in particular, uranium are dealt with in great detail among inorganic pollutants because of their occurrence in many European countries. Construction methods for cut-off walls and reactive barriers exhibit similar features. Apart from conventional methods, drilling, deep soil mixing, jet technology, arrays of wells, injected systems and biobarriers are applied to construct permeable reactive barriers. Permeable reactive barriers bear great potential for the future in remediation engineering. (orig.)

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

Tecnologie dell’informazione e nuovi processi di vittimizzazione / Nouvelles technologies et processus de victimisation / Information technologies and new processes of victimisation

Directory of Open Access Journals (Sweden)

Marotta Gemma

2012-08-01

Full Text Available New technologies, on the one hand, have produced undeniable positive effects, from the acceleration of cultural diffusion to the communication between "worlds" previously unknown; on the other hand, they have become now an instrument to commit new crimes and deviants acts.In the article we will discuss the processes of victimization related to specific offenses (digital identity theft, online paedopornography, cyberstalking and to new forms of addiction due to the new media. The aim is to highlight the dangers of the misuse or abuse of new technologies.S'il est vrai que les nouvelles technologies de communication ont produit des effets positifs indéniables, comme l'accélération de la diffusion culturelle et l'échange entre « mondes » jusque-là inconnus, elles n'en sont pas moins devenues un moyen de commettre des actes déviants et criminels nouveaux.Cet article expose les processus de victimisation liés à certains crimes (comme l'usurpation d'identité, la pédopornographie en ligne, le cyber-harcèlement, et de nouvelles formes de dépendance, afin de mettre en évidence les dangers d'un usage pervers ou délictueux des nouveaux médias.

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

Building Open in Engineering

OpenAIRE

Berg, Devin

2018-01-01

A description of ongoing efforts to build a culture for open in engineering. I will overview some of the tools that have been developed to promote open practices in engineering and discuss some of the barriers to adoption within the field.Presented 27 March 2018 at the "E"ffordabilitiy Summit, Menomonie, WI.

Securite, dangerosite, biopolitique: trois versants d'une nouvelle pratique de pouvoir sur les individus

Directory of Open Access Journals (Sweden)

Jean-François Bert

2012-01-01

Full Text Available Le questionnement de Foucault sur la judiciarisation des sociétés contemporaines renvoie à plusieurs controverses qui, entre 1974 et 1976, ont spécifiquement concerné la question du vivant comme de son rapport au champ du droit et des institutions politiques. Ces polémiques se sont cristallisées autour d'affaires judiciaires retentissantes mais également autour d'un discours technique et politique qui donne une place nouvelle aux notions de dangerosité, de sécurité et à la question plus générale de la gestion du vivant. Trois discours qui, pour Foucault, sont révélateur d'un profond changement de société et de mode de gouvernement des individus.

Le décodage biologique. Diffusion d’une nouvelle médecine non-conventionnelle contre le cancer Biodecoding. Dissemination of a New Unconventional Therapy against Cancer

Directory of Open Access Journals (Sweden)

Aline Sarradon-Eck

2011-05-01

Full Text Available De nouvelles médecines alternatives, regroupées sous l’appellation « décodage biologique », reposent sur une conception psychosomatique du cancer. Elles sont apparues en Europe dans les années 1990. Dans une perspective critique, l’article tente de comprendre la diffusion de ces nouvelles thérapies. S’inspirant du travail de D. Fassin sur les réseaux de l’ethnopsychiatrie, il analyse la construction d’une légitimation du décodage biologique et de ses praticiens, en décrivant les réseaux qui diffusent les théories et favorisent l’adoption de la pratique. L’article montre l’enracinement de ces nouvelles thérapies dans des représentations sociales et des modèles culturels de l’étiologie du cancer et du “faire face” à la maladie qui permettent ou renforcent l’adoption et l’appropriation de la pensée psychosomatique alternative.New alternative therapy called « bio-decoding » based on a psychosomatic perception of cancer appeared in the 1990s. Using a critical approach, the article aims to understand the therapy’s growth. Drawing on D. Fassin’s work about ethnopsychiatric networks, this paper analyses the construction of bio-decoding and bio-therapist legitimacy, by unravelling the networks which allow for theory dissemination and enable the practice’s growth. The article shows that these new therapies are deeply rooted in social and cultural models of cancer etiology and coping, which allow or reinforce approval and appropriation of alternative psychosomatic thought.

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)

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)

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

Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

Science.gov (United States)

Zhu, Dongming; Miller, Robert A.

2000-01-01

Thermal barrier coatings have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, the issue of coating durability under high temperature cyclic conditions is still of major concern. The coating failure is closely related to thermal stresses and oxidation in the coating systems. Coating shrinkage cracking resulting from ceramic sintering and creep at high temperatures can further accelerate the coating failure process. The purpose of this paper is to address critical issues such as ceramic sintering and creep, thermal fatigue and their relevance to coating life prediction. Novel test approaches have been established to obtain critical thermophysical and thermomechanical properties of the coating systems under near-realistic temperature and stress gradients encountered in advanced engine systems. Emphasis is placed on the dynamic changes of the coating thermal conductivity and elastic modulus, fatigue and creep interactions, and resulting failure mechanisms during the simulated engine tests. Detailed experimental and modeling results describing processes occurring in the thermal barrier coating systems provide a framework for developing strategies to manage ceramic coating architecture, microstructure and properties.

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)

The Barrier code for predicting long-term concrete performance

International Nuclear Information System (INIS)

Shuman, R.; Rogers, V.C.; Shaw, R.A.

1989-01-01

There are numerous features incorporated into a LLW disposal facility that deal directly with critical safety objectives required by the NRC in 10 CFR 61. Engineered barriers or structures incorporating concrete are commonly being considered for waste disposal facilities. The Barrier computer code calculates the long-term degradation of concrete structures in LLW disposal facilities. It couples this degradation with water infiltration into the facility, nuclide leaching from the waste, contaminated water release from the facility, and associated doses to members of the critical population group. The concrete degradation methodology of Barrier is described

Literaire strategieën: de drie satellieten van La Nouvelle Revue Française (1910-1914

Directory of Open Access Journals (Sweden)

Maaike Koffeman

2000-12-01

Full Text Available La Nouvelle Revue Française, opgericht in 1908 door een groep schrijvers rond André Gide, is het belangrijkste Franse literaire maandblad van het interbellum geweest. In de jaren voorafgaand aan de Eerste Wereldoorlog is de reputatie van het tijdschrift nog relatief bescheiden, maar er is al wel een duidelijke progressie te constateren. Deze is niet alleen toe te schrijven aan de inhoudelijke kwaliteit van de bijdragen, maar vooral ook aan de manier waaorp de redactie het tijdschrift promoot. De oprichters bedienen zich van een 'mutimedia-strategie': zij ontwikkelen rond de NRF verschillende nevenactiviteiten om de naamsbekendheid van het tijdschrift te vergroten en zijn literatuuropvattingen onder een breder publiek te verspreiden. 

Passive Barriers to Inadvertent Human Intrusion for Use at the Nevada Test Site

International Nuclear Information System (INIS)

NSTec Environmental Management

2007-01-01

In July1996, BN transmitted Passive Barriers to Inadvertent Human Intrusion for Use at the Nevada Test Site to the United States Department of Energy, under Contract DE-AC08-91NV10833. The 1996 paper had a limited distribution and was not reviewed for public release. In 2007, National Security Technologies LLC (NSTec) made minor revisions to conform to current editorial standards of the NNSA/NSO and to meet current security requirements for public release. The primary purpose of this study was to identify types of engineered passive barriers that could deter future intrusion into buried low-level radioactive waste, particularly intrusion by drilling water wells. The study considered drilling technology, many natural and man-made materials, and both underground and above-ground barriers. Based on cost and effectiveness, the report recommended underground barriers consisting of a layer of rubble or tires. An aboveground barrier mound might also prove effective, but would cost more, and may become an attractive nuisance (e.g., might, after their purpose has been forgotten, encourage exploration for the sake of satisfying curiosity). Advances in drilling technology could render any engineered barriers ineffective if there is motivation to penetrate the barriers

Development and Life Prediction of Erosion Resistant Turbine Low Conductivity Thermal Barrier Coatings

Science.gov (United States)

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

2010-01-01

Future rotorcraft propulsion systems are required to operate under highly-loaded conditions and in harsh sand erosion environments, thereby imposing significant material design and durability issues. The incorporation of advanced thermal barrier coatings (TBC) in high pressure turbine systems enables engine designs with higher inlet temperatures, thus improving the engine efficiency, power density and reliability. The impact and erosion resistance of turbine thermal barrier coating systems are crucial to the turbine coating technology application, because a robust turbine blade TBC system is a prerequisite for fully utilizing the potential coating technology benefit in the rotorcraft propulsion. This paper describes the turbine blade TBC development in addressing the coating impact and erosion resistance. Advanced thermal barrier coating systems with improved performance have also been validated in laboratory simulated engine erosion and/or thermal gradient environments. A preliminary life prediction modeling approach to emphasize the turbine blade coating erosion is also presented.

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

Selection of barrier metals for a waste package in tuff

International Nuclear Information System (INIS)

Russell, E.W.; McCright, R.D.; O'Neal, W.C.

1983-10-01

The Nevada Nuclear Waste Storage Investigations (NNWSI) project under the Civilian Radioactive Waste Management Program is planning a repository at Yucca Mountain at the Nevada Test Site for isolation of high-level nuclear waste. Lawrence Livermore National Laboratory is developing designs for an engineered barrier system containing several barriers such as the waste form, a canister and/or an overpack, packing, and near field host rock. In this paper we address the selection of metal containment barriers. 13 references, 4 tables

Performance modeling of concrete/metal barriers used in low-level waste disposal

International Nuclear Information System (INIS)

Shuman, R.; Chau, Nam; Icenhour, A.S.; Godbee, H.W.; Tharp, M.L.

1993-01-01

Low-Level radioactive wastes generated in government and commercial operations involving nuclear materials need to be isolated from the environment almost in perpetuity. An increasing number of disposal sites are using concrete/metal barriers (so called ''engineered'' barriers) to isolate these wastes from the environment. Two major concerns hamper the use of engineered barriers; namely, the lack of ability to reliably predict the service life of these barriers and to estimate the confidence level of the service life predicted. Computer codes (SOURCE1 and SOURCE2) for estimating the long-term (centuries to millennia) service life of these barriers are presented. These codes use mathematical models (based on past observations, currently accepted data, and established theories) to predict behavior into the future. Processes modeled for concrete degradation include sulfate attack, calcium hydroxide leaching, and reinforcement corrosion. The loss of structural integrity due to cracking is also modeled. Mechanisms modeled for nuclide leaching include advection and diffusion. The coupled or linked effects of these models are addressed in the codes. Outputs from the codes are presented and analyzed

Durability and CMAS Resistance of Advanced Environmental Barrier Coatings Systems for SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming

2015-01-01

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. This paper will emphasize advanced environmental barrier coating developments for SiCSiC turbine airfoil components, by using advanced coating compositions and processing, in conjunction with mechanical and environment testing and durability validations. The coating-CMC degradations and durability in the laboratory simulated engine fatigue-creep and complex operating environments are being addressed. The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will be discussed. The results help understand the advanced EBC-CMC system performance, aiming at the durability improvements of more robust, prime-reliant environmental barrier coatings for successful applications of the component technologies and lifing methodologies.

Effect of translucence of engineering ceramics on heat transfer in diesel engines. Final report

Energy Technology Data Exchange (ETDEWEB)

Wahiduzzaman, S.; Morel, T. [Integral Technologies, Inc., Westmont, IL (United States)

1992-04-01

This report describes the experimental portion of a broader study undertaken to assess the effects of translucence of ceramic materials used as thermal barrier coatings in diesel engines. In an earlier analytical work a parametric study was performed, varying several radiative properties over ranges typical of engineering ceramics, thereby identifying the most important radiative properties and their impact on in-cylinder heat transfer. In the current study these properties were experimentally determined for several specific zirconia coatings considered for thermal barrier applications in diesel engines. The methodology of this study involved formulation of a model capable of describing radiative transfer through a semitransparent medium as a function of three independent model parameters, ie, absorption coefficient, scattering coefficient and refractive index. For the zirconia-based ceramics investigated in this study, it was concluded that for usual coating thicknesses (1.5--2.5 mm) these ceramics are optically thick and hence, are effective as radiative heat transfer barriers. These ceramics possess high scattering coefficients and low absorption coefficients causing them to be highly reflective (60-80%) in the spectral region where thermal radiation is important. The performance of the investigated ceramics and the mechanism of heat transfer were found to depend on surface condition, specifically on soot deposition. Thus, to insure the optimum thermal barrier operation for either clean or heavily sooted surfaces, a ceramic material with high scattering coefficient provides the best choice.

Hanford Permanent Isolation Barrier Program: Asphalt technology test plan

Energy Technology Data Exchange (ETDEWEB)

Freeman, H.D.; Romine, R.A.

1994-05-01

The Hanford Permanent Isolation Barriers use engineered layers of natural materials to create an integrated structure with backup protective features. The objective of current designs is to develop a maintenance-free permanent barrier that isolates wastes for a minimum of 1000 years by limiting water drainage to near-zero amounts. Asphalt is being used as an impermeable water diversion layer to provide a redundant layer within the overall barrier design. Data on asphalt barrier properties in a buried environment are not available for the required 100-year time frame. The purpose of this test plan is to outline the activities planned to obtain data with which to estimate performance of the asphalt layers.

Hanford Permanent Isolation Barrier Program: Asphalt technology test plan

International Nuclear Information System (INIS)

Freeman, H.D.; Romine, R.A.

1994-05-01

The Hanford Permanent Isolation Barriers use engineered layers of natural materials to create an integrated structure with backup protective features. The objective of current designs is to develop a maintenance-free permanent barrier that isolates wastes for a minimum of 1000 years by limiting water drainage to near-zero amounts. Asphalt is being used as an impermeable water diversion layer to provide a redundant layer within the overall barrier design. Data on asphalt barrier properties in a buried environment are not available for the required 100-year time frame. The purpose of this test plan is to outline the activities planned to obtain data with which to estimate performance of the asphalt layers

La mosquée en Algérie.Figures nouvelles et pratiques reconstituées

Directory of Open Access Journals (Sweden)

Abderrahmane Moussaoui

2012-07-01

Full Text Available La « globalisation » des discours de la mosquée casse les frontières érigées historiquement par les différentes écoles, et tend à réduire la fracture inaugurale entre sunnisme et chiisme. Aujourd’hui il y a un retour à la Salafiya qui ne reconnaît que les fondamentaux. Tout le reste est considéré comme de l’ordre de l’historique et donc non sacré et à ce titre susceptible d’être laissé de côté ou changé. La Salafiya continue cependant à être divisée entre djâmida et djihâdiya.Les pratiques au sein de la mosquée procèdent également par pluralisation où l’individu cherche à la fois à signaler son individualité mais aussi à s’inscrire dans des tendances plus globales. Les récits de vie de différents imams laisse transparaître une sorte de sécularisation interne de la mosquée et une plus grande latitude dans la ré interprétation de l’initial.Les changements sont perceptibles également au niveau des acteurs De nouvelles figures concurrencent celle classique de l’imam. Le prédicateur, sans être une figure tout à fait nouvelle, ni une invention récente, demeure une figure réinventée. Au Maghreb, on connaît l’imam, le mufti, le taleb, mais moins le dâ`îya que les chaînes de télévision à thématique religieuse ont fini par imposer.Ce sont toutes ces transformations qui se déroulent au cœur de l’institution la plus significative de l’Islam que tente d’examiner cette contribution.

Microstructure Evolution and Durability of Advanced Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Evans, Laura J.; McCue, Terry R.; Harder, Bryan

2016-01-01

Environmental barrier coated SiC-SiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. Advanced HfO2 and rare earth silicate environmental barrier coatings (EBCs), along with multicomponent hafnium and rare earth silicide EBC bond coats have been developed. The coating degradation mechanisms in the laboratory simulated engine thermal cycling, and fatigue-creep operating environments are also being investigated. This paper will focus on the microstructural and compositional evolutions of an advanced environmental barrier coating system on a SiC-SiC CMC substrate during the high temperature simulated durability tests, by using a Field Emission Gun Scanning Electron Microscopy, Energy Dispersive Spectroscopy (EDS) and Wavelength Dispersive Spectroscopy (WDS). The effects of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the degradation mechanisms of the environmental barrier coating systems will also be discussed. The detailed analysis results help understand the EBC-CMC system performance, aiming at the durability improvements to achieve more robust, prime-reliant environmental barrier coatings.

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

Experimental methodology to study radionuclide sorption and migration in geological formations and engineered barriers of waste repositories; Metodologia experimental para estudios de sorcion y migracion de radionucleidos en formaciones geologicas y barreras de almacenamientos de residuos

Energy Technology Data Exchange (ETDEWEB)

Rojo Sanz, H.

2010-07-01

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.

Permanent isolation surface barrier development plan

International Nuclear Information System (INIS)

Wing, N.R.

1994-01-01

The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no open-quotes provenclose quotes long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems

Permanent isolation surface barrier development plan

Energy Technology Data Exchange (ETDEWEB)

Wing, N.R.

1994-01-01

The exhumation and treatment of wastes may not always be the preferred alternative in the remediation of a waste site. In-place disposal alternatives, under certain circumstances, may be the most desirable alternatives to use in the protection of human health and the environment. The implementation of an in-place disposal alternative will likely require some type of protective covering that will provide long-term isolation of the wastes from the accessible environment. Even if the wastes are exhumed and treated, a long-term barrier may still be needed to adequately dispose of the treated wastes or any remaining waste residuals. Currently, no {open_quotes}proven{close_quotes} long-term barrier is available. The Hanford Site Permanent Isolation Surface Barrier Development Program (BDP) was organized to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site. The permanent isolation barrier technology also could be used at other sites. Permanent isolation barriers use engineered layers of natural materials to create an integrated structure with redundant protective features. Drawings of conceptual permanent isolation surface barriers are shown. The natural construction materials (e.g., fine soil, sand, gravel, riprap, asphalt) have been selected to optimize barrier performance and longevity. The objective of current designs is to use natural materials to develop a maintenance-free permanent isolation surface barrier that isolates wastes for a minimum of 1,000 years by limiting water drainage to near-zero amounts; reducing the likelihood of plant, animal, and human intrusion; controlling the exhalation of noxious gases; and minimizing erosion-related problems.

SEMINAIRE DE L'ENSEIGNEMENT TECHNIQUE Nouvelles Technologies en Tuyauteries Multicouches - French version only

CERN Multimedia

Davide Vitè

2002-01-01

Mardi 28 mai, mercredi 29 mai 28 mai, 9:30 - 12:00 - Training Centre Auditorium, Room 11, bldg. 593 28 mai, 14:00 - 17:00; 29 mai, 9:00 - 12:00 - Training Centre Rooms 13 and 15, bldg. 593 Nouvelles Technologies en Tuyauteries Multicouches Jacques Dougoud / GEBERIT SA, Lausanne, Suisse Mario Bettini / GEORG FISCHER PFCI S.r.l., Peschiera del Garda, Brescia, Italie Christian Tacco / VALSIR S.P.A., Vestone, Brescia, Italie Depuis quelques années l'apparition de tubes multicouches a changé radicalement la conception des tuyauteries, tant pour les applications industrielles que domestiques. Les utilisations au CERN concernent pratiquement tous les fluides, c'est-à-dire eau sanitaire, eau déminéralisée, air comprimé, fluorocarbones liquides ou gazeux, et tous les gaz, depuis l'hélium jusqu'au xénon. Ce séminaire de l'Enseignement Technique est adressé à toute personne concern&eac...

A Molecular Toolbox to Engineer Site-Specific DNA Replication Perturbation.

Science.gov (United States)

Larsen, Nicolai B; Hickson, Ian D; Mankouri, Hocine W

2018-01-01

Site-specific arrest of DNA replication is a useful tool for analyzing cellular responses to DNA replication perturbation. The E. coli Tus-Ter replication barrier can be reconstituted in eukaryotic cells as a system to engineer an unscheduled collision between a replication fork and an "alien" impediment to DNA replication. To further develop this system as a versatile tool, we describe a set of reagents and a detailed protocol that can be used to engineer Tus-Ter barriers into any locus in the budding yeast genome. Because the Tus-Ter complex is a bipartite system with intrinsic DNA replication-blocking activity, the reagents and protocols developed and validated in yeast could also be optimized to engineer site-specific replication fork barriers into other eukaryotic cell types.

A Molecular Toolbox to Engineer Site-Specific DNA Replication Perturbation

DEFF Research Database (Denmark)

Larsen, Nicolai B; Hickson, Ian D; Mankouri, Hocine W

2018-01-01

" impediment to DNA replication. To further develop this system as a versatile tool, we describe a set of reagents and a detailed protocol that can be used to engineer Tus-Ter barriers into any locus in the budding yeast genome. Because the Tus-Ter complex is a bipartite system with intrinsic DNA replication......Site-specific arrest of DNA replication is a useful tool for analyzing cellular responses to DNA replication perturbation. The E. coli Tus-Ter replication barrier can be reconstituted in eukaryotic cells as a system to engineer an unscheduled collision between a replication fork and an "alien......-blocking activity, the reagents and protocols developed and validated in yeast could also be optimized to engineer site-specific replication fork barriers into other eukaryotic cell types....

Biomaterials for tissue engineering: summary

Science.gov (United States)

Christenson, L.; Mikos, A. G.; Gibbons, D. F.; Picciolo, G. L.; McIntire, L. V. (Principal Investigator)

1997-01-01

This article summarizes presentations and discussion at the workshop "Enabling Biomaterial Technology for Tissue Engineering," which was held during the Fifth World Biomaterials Congress in May 1996. Presentations covered the areas of material substrate architecture, barrier effects, and cellular response, including analysis of biomaterials challenges involved in producing specific tissue-engineered products.

InGaP Heterojunction Barrier Solar Cells

Science.gov (United States)

Welser, Roger E. (Inventor)

2014-01-01

A new solar cell structure called a heterojunction barrier solar cell is described. As with previously reported quantum-well and quantum-dot solar cell structures, a layer of narrow band-gap material, such as GaAs or indium-rich InGaP, is inserted into the depletion region of a wide band-gap PN junction. Rather than being thin, however, the layer of narrow band-gap material is about 400-430 nm wide and forms a single, ultrawide well in the depletion region. Thin (e.g., 20-50 nm), wide band-gap InGaP barrier layers in the depletion region reduce the diode dark current. Engineering the electric field and barrier profile of the absorber layer, barrier layer, and p-type layer of the PN junction maximizes photogenerated carrier escape. This new twist on nanostructured solar cell design allows the separate optimization of current and voltage to maximize conversion efficiency.

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

Energy and greenhouse gas profile of the Nouvelle Aquitaine region. Release 2017

International Nuclear Information System (INIS)

Rousset, Alain; Poitevin, Lionel; Loeb, Amandine; Philippot, Herve; Rebouillat, Lea; Jacquelin, Antoine

2017-06-01

This publication first proposes graphs and comments characterising final energy consumption of the Nouvelle Aquitaine region: regional situation in 2015 (analysis per sector and per energy), primary resources, social-economic analysis (energy bill, level of energy poverty, burden due to old housing and commuting for households), evolution of energy consumption between 2005 and 2015 (per sector, per source of energy, evolution of energy intensity and of the energy bill). The next part addresses greenhouse gas emissions: regional situation in 2015 (distribution in terms of emission type and per gas), evolutions between 1990 and 2015, evolutions per sector. The third part addresses renewable energies: regional situation for the different types of renewable energy, comparison with final energy consumption, comparison with national data, production evolutions, focus per sector (wood and wood by-products, heat pumps in the housing sector, urban waste valorisation units, biogas valorisation, bio-fuels, wind energy, hydroelectricity, solar photovoltaic). The last part recalls national objectives related to energy, to greenhouse gas emissions for France and for the region, in relationship with the law on energy transition and for a green growth

Barrier performance researches for the safety evaluation

International Nuclear Information System (INIS)

Niibori, Yuichi

2004-01-01

So far, many researches were conducted to propose a scientific evidence (a safety case) for the realization of geological disposal in Japan. In order to regulate the geological disposal system of radioactive wastes, on the other hand, we need also a holistic approach to integrate various data related for the performance evaluations of the engineered barrier system and the natural barrier system. However, the scientific bases are not sufficient to establish the safety regulation for such a natural system. For example, we often apply the specific probability density function (PDF) to the uncertainty of barrier system due to the essential heterogeneity. However, the applicability is not clear in the regulation point of view. A viewpoint to understand such an applicability of PDFs has been presented. (author)

Contaminant fluxes through site containment barriers: Performance assessment and illustrative results

International Nuclear Information System (INIS)

Vita, C.L.

1994-01-01

Contaminant mass flux by advective and diffusive transport is predicted for five containment barriers that use one or more clay liners, flexible membrane liners (FMLs), or liquid collection and removal systems (LCRS)s. Barriers are engineered systems intended to contain and isolate site contaminants from the environment. Barriers include liners, caps, and cutoff walls. Barriers may be used in contaminated-site cleanups (including CERCLA and RCRA), RCRA landfills, or other RCRA TSDFs. Concepts are provided for barrier performance assessment, including analysis and optimization, for meeting performance requirements and controlling risk at minimum cost. Concepts and results can help in planning, designing, or evaluating and communicating, the use or effectiveness of proposed or existing barriers for site cleanups or waste containment. 15 refs., 6 figs., 5 tabs

SURFACE-ALTERED ZEOLITES AS PERMEABLE BARRIERS FOR IN SITU TREATMENT OF CONTAMINATED GROUNDWATER

International Nuclear Information System (INIS)

Bowman, Robert S.; Li, Zhaohui; Roy, Stephen J.; Burt, Todd; Johnson, Timothy L.; Johnson, Richard L.

1999-01-01

The overall objective of this effort is to develop and test a zeolite-based permeable barrier system for containing and remediating contaminated groundwater. The projected product is an engineered and tested permeable barrier system that can be adopted by the commercial sector

SURFACE-ALTERED ZEOLITES AS PERMEABLE BARRIERS FOR IN SITU TREATMENT OF CONTAMINATED GROUNDWATER

Energy Technology Data Exchange (ETDEWEB)

Robert S. Bowman; Zhaohui Li; Stephen J. Roy; Todd Burt; Timothy L. Johnson; Richard L. Johnson

1999-08-30

The overall objective of this effort is to develop and test a zeolite-based permeable barrier system for containing and remediating contaminated groundwater. The projected product is an engineered and tested permeable barrier system that can be adopted by the commercial sector.

Air barrier systems: Construction applications

Energy Technology Data Exchange (ETDEWEB)

Perrault, J.C

1989-01-01

An examination is presented of how ordinary building materials can be used in an innovative manner to design, detail, and construct effective air barrier systems for common types of walls. For residential construction, the air drywall approach uses the interior gypsum board as the main component of the wall air barrier system. Joints between the gypsum board and adjacent materials or assemblies are sealed by gaskets. In commercial construction, two different techniques are employed for using gypsum board as air barrier material: the accessible drywall and non-accessible drywall approaches. The former is similar to the air drywall approach except that high performance sealants are used instead of gaskets. In the latter approach, exterior drywall sheathing is the main component of the air barrier system; joints between boards are taped and joints between boards and other components are sealed using elastomeric membrane strips. For various types of commercial and institutional buildings, metal air barrier systems are widely used and include pre-engineered curtain walls or sheet metal walls. Masonry wall systems are regarded as still the most durable, fireproof, and soundproof wall type available but an effective air barrier system has typically been difficult to implement. Factory-made elastomeric membranes offer the potential to provide airtightness to masonry walls. These membranes are applied on the entire masonry wall surface and are used to make airtight connections with other building components. Two types of product are available: thermofusible and peel-and-stick membranes. 5 figs.

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.

Une voix dans un chœur risque de n’être point entendue. André Gide et La Nouvelle Revue française, 1908-1914

NARCIS (Netherlands)

Koffeman, M.N.; Wittmann, Jean-Michel

2017-01-01

Cet article étudie la tension entre l’individualisme gidien et la collectivité littéraire que forme la première Nouvelle revue française. Entreprise commune par excellence, la revue gagne à être considérée dans son ensemble. Une lecture des sommaires de la NRF relativise le rôle de Gide et met en

Test des photomultiplicateurs en silicium couplés à un scintillateur plastique pour la nouvelle Tape Station

CERN Document Server

sekal, Smain

2014-01-01

L’une des parties essentielles de la l’installation ISOLDE est la tape Station (contrôleur de bandes), qui permet la vérification de la qualité du faisceau délivré aux expériences. On prévoit à ISOLDE de remplacer l’ancienne Tape Station, par une nouvelle Tape station; et l’un des paramètres essentiels pour la performance de la tape Station est l’efficacité de détection. Le but de ce travail est de vérifier l’efficacité des détecteurs de particules bêta, composés par l’association des photomultiplicateurs en Silicium à un scintillateur plastique pour differentes distances.

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)

Development of construction methods for high-density bentonite barriers using premixed spraying. Part 1. Laboratory tests on methods of spraying roughly crushed bentonite and investigation of mixing methods

International Nuclear Information System (INIS)

Kobayashi, Ichizo; Tanaka, Toshiyuki; Nakajima, Makoto; Toida, Masaru

2006-01-01

According to the present concept of geological disposal of radioactive waste, a disposal facility should consist of a bentonite-engineered barrier, a cementitious-engineered barrier, and natural barriers. To guarantee the validity of the geological disposal concept, the bentonite-engineered barrier must have high impermeability. However, an effective construction method for high-density bentonite-engineered barriers in narrow spaces such as those in radioactive waste geological disposal sites has not been developed. Therefore, the authors have developed a spraying method that has high workability in narrow spaces as a method of constructing bentonite-engineered barriers in narrow spaces. This paper describes the production method for a spraying material and an examination through spraying tests of the spraying distance, the shapes of the spray nozzles, and the ratio of spraying material to air. The test results confirmed that a bentonite-engineered barrier of dry density 1.6 Mg/m 3 could be constructed using the spraying method developed and that the appropriate spraying conditions for the construction of high-density bentonite barriers were obtained. Moreover, the authors developed a construction quality management method using the silicon oil specific-gravity method that can clearly and promptly indicate the dry density of the sprayed bentonite. (author)

Full-participation of students with physical disabilities in science and engineering laboratories.

Science.gov (United States)

Jeannis, Hervens; Joseph, James; Goldberg, Mary; Seelman, Katherine; Schmeler, Mark; Cooper, Rory A

2018-02-01

To conduct a literature review identifying barriers and facilitators students with physical disabilities (SwD-P) may encounter in science and engineering (S&E) laboratories. Publications were identified from 1991 to 2015 in ERIC, web of science via web of knowledge, CINAHL, SCOPUS, IEEEXplore, engineering village, business source complete and PubMed databases using search terms and synonyms for accommodations, advanced manufacturing, additive manufacturing, assistive technology (AT), barriers, engineering, facilitators, instructor, laboratory, STEM education, science, students with disabilities and technology. Twenty-two of the 233 publications that met the review's inclusion criteria were examined. Barriers and facilitators were grouped based on the international classification of functioning, disability and health framework (ICF). None of the studies directly found barriers or facilitators to SwD-P in science or engineering laboratories within postsecondary environments. The literature is not clear on the issues specifically related to SwD-P. Given these findings, further research (e.g., surveys or interviews) should be conducted to identify more details to obtain more substantial information on the barriers that may prevent SwD-P from fully participating in S&E instructional laboratories. Implications for Rehabilitation Students with disabilities remain underrepresented going into STEM careers. A need exist to help uncover barriers students with disabilities encounter in STEM laboratory. Environments. Accommodations and strategies that facilitate participation in STEM laboratory environments are promising for students with disabilities.

Yankaya Dilek, La nouvelle bourgeoisie islamique. Le modèle turc, Presses universitaires de France, coll. Proche Orient, 2013, 216 p.

OpenAIRE

Özatalay , Cem

2014-01-01

International audience; Paru en mars 2013, le livre de Dilek Yankaya intitulé La nouvelle bourgeoisie islamique. Le modèle turc apporte une contribution remarquable pour comprendre les dynamiques sociales qui sous-tendent la polarisation politique et culturelle qui marque tout autant l’histoire récente de la Turquie que les événements de Gezi. En mettant en lumière les aspirations et la conscience de classe de la bourgeoisie islamique en formation, Yankaya essaie de montrer dans son ouvrage c...

Laboratory Testing of a MEMS Sensor System for In-Situ Monitoring of the Engineered Barrier in a Geological Disposal Facility

Directory of Open Access Journals (Sweden)

Wenbin Yang

2017-05-01

Full Text Available Geological disposal facilities for radioactive waste pose significant challenges for robust monitoring of environmental conditions within the engineered barriers that surround the waste canister. Temperatures are elevated, due to the presence of heat generating waste, relative humidity varies from 20% to 100%, and swelling pressures within the bentonite barrier can typically be 2–10 MPa. Here, we test the robustness of a bespoke design MEMS sensor-based monitoring system, which we encapsulate in polyurethane resin. We place the sensor within an oedometer cell and show that despite a rise in swelling pressure to 2 MPa, our relative humidity (RH measurements are unaffected. We then test the sensing system against a traditional RH sensor, using saturated bentonite with a range of RH values between 50% and 100%. Measurements differ, on average, by 2.87% RH, and are particularly far apart for values of RH greater than 98%. However, bespoke calibration of the MEMS sensing system using saturated solutions of known RH, reduces the measurement difference to an average of 1.97% RH, greatly increasing the accuracy for RH values close to 100%.

Experimental evaluation of optimization method for developing ultraviolet barrier coatings

Science.gov (United States)

Gonome, Hiroki; Okajima, Junnosuke; Komiya, Atsuki; Maruyama, Shigenao

2014-01-01

Ultraviolet (UV) barrier coatings can be used to protect many industrial products from UV attack. This study introduces a method of optimizing UV barrier coatings using pigment particles. The radiative properties of the pigment particles were evaluated theoretically, and the optimum particle size was decided from the absorption efficiency and the back-scattering efficiency. UV barrier coatings were prepared with zinc oxide (ZnO) and titanium dioxide (TiO2). The transmittance of the UV barrier coating was calculated theoretically. The radiative transfer in the UV barrier coating was modeled using the radiation element method by ray emission model (REM2). In order to validate the calculated results, the transmittances of these coatings were measured by a spectrophotometer. A UV barrier coating with a low UV transmittance and high VIS transmittance could be achieved. The calculated transmittance showed a similar spectral tendency with the measured one. The use of appropriate particles with optimum size, coating thickness and volume fraction will result in effective UV barrier coatings. UV barrier coatings can be achieved by the application of optical engineering.

Flutter and galloping of cable-supported bridges with porous wind barriers

Czech Academy of Sciences Publication Activity Database

Buljac, A.; Kozmar, H.; Pospíšil, S.; Macháček, Michael

2017-01-01

Roč. 171, December (2017), s. 304-318 ISSN 0167-6105 R&D Projects: GA ČR(CZ) GA15-01035S; GA MŠk(CZ) LO1219 Keywords : cable-supported bridges * porous wind barriers * aerodynamic forces and moments * flutter * galloping * wind-tunnel experiments Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering , Municipal and structural engineering Impact factor: 2.049, year: 2016 http://www.sciencedirect.com/science/ article /pii/S016761051730435X

Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composites: Recent Advances and Future Directions

Science.gov (United States)

Zhu, Dongming

2016-01-01

This presentation briefly reviews the SiC/SiC major environmental and environment-fatigue degradations encountered in simulated turbine combustion environments, and thus NASA environmental barrier coating system evolution for protecting the SiC/SiC Ceramic Matrix Composites for meeting the engine performance requirements. The presentation will review several generations of NASA EBC materials systems, EBC-CMC component system technologies for SiC/SiC ceramic matrix composite combustors and turbine airfoils, highlighting the temperature capability and durability improvements in simulated engine high heat flux, high pressure, high velocity, and with mechanical creep and fatigue loading conditions. This paper will also focus on the performance requirements and design considerations of environmental barrier coatings for next generation turbine engine applications. The current development emphasis is placed on advanced NASA candidate environmental barrier coating systems for SiC/SiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. The efforts have been also directed to developing prime-reliant, self-healing 2700F EBC bond coat; and high stability, lower thermal conductivity, and durable EBC top coats. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, erosion-impact resistance, and long-term fatigue-environment system durability performance will be described. The research and development opportunities for turbine engine environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling will be briefly discussed.

Awards and Honours

CERN Multimedia

CERN Bulletin

2011-01-01

On 8 December 2010, Phillippe Lebrun was named Engineer of the Year by L’Usine Nouvelle and the Engineers and Scientists of France for his work on the LHC’s superconducting magnets and cryogenic cooling systems.

Optimal design of wind barriers using 3D computational fluid dynamics simulations

Science.gov (United States)

Fang, H.; Wu, X.; Yang, X.

2017-12-01

Desertification is a significant global environmental and ecological problem that requires human-regulated control and management. Wind barriers are commonly used to reduce wind velocity or trap drifting sand in arid or semi-arid areas. Therefore, optimal design of wind barriers becomes critical in Aeolian engineering. In the current study, we perform 3D computational fluid dynamics (CFD) simulations for flow passing through wind barriers with different structural parameters. To validate the simulation results, we first inter-compare the simulated flow field results with those from both wind-tunnel experiments and field measurements. Quantitative analyses of the shelter effect are then conducted based on a series of simulations with different structural parameters (such as wind barrier porosity, row numbers, inter-row spacing and belt schemes). The results show that wind barriers with porosity of 0.35 could provide the longest shelter distance (i.e., where the wind velocity reduction is more than 50%) thus are recommended in engineering designs. To determine the optimal row number and belt scheme, we introduce a cost function that takes both wind-velocity reduction effects and economical expense into account. The calculated cost function show that a 3-row-belt scheme with inter-row spacing of 6h (h as the height of wind barriers) and inter-belt spacing of 12h is the most effective.

MOOCs et mobilités étudiantes : vers une nouvelle circulation des connaissances ? Observations au regard de l&8217;Afrique francophone

OpenAIRE

Meyer, Jean-Baptiste

2017-01-01

Les discours actuels sur l'internationalisation de l'enseignement supérieur font grand cas des cours à distance en diffusion libre et massive. Ils offrent des possibilités nouvelles de transmettre des connaissances élaborées, à un grand nombre de personnes, et sans recours à d'autres supports qu'un ordinateur connecté. Ces modalités en font un outil prometteur de transfert ou de partage international, puisque les frontières des pays sont effacées par la transmission numérique. Elles peuvent d...

Creep Behavior of Hafnia and Ytterbium Silicate Environmental Barrier Coating Systems on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Fox, Dennis S.; Ghosn, Louis J.; Harder, Bryan

2011-01-01

Environmental barrier coatings will play a crucial role in future advanced gas turbine engines because of their ability to significantly extend the temperature capability and stability of SiC/SiC ceramic matrix composite (CMC) engine components, thus improving the engine performance. In order to develop high performance, robust coating systems for engine components, appropriate test approaches simulating operating temperature gradient and stress environments for evaluating the critical coating properties must be established. In this paper, thermal gradient mechanical testing approaches for evaluating creep and fatigue behavior of environmental barrier coated SiC/SiC CMC systems will be described. The creep and fatigue behavior of Hafnia and ytterbium silicate environmental barrier coatings on SiC/SiC CMC systems will be reported in simulated environmental exposure conditions. The coating failure mechanisms will also be discussed under the heat flux and stress conditions.

Tribological and wear behavior of yttria stabilized zirconia thermal barrier coatings on mild steel

International Nuclear Information System (INIS)

Farooq, M.; Pervez, A.

2012-01-01

The perfection of the temperature confrontation of the engine essentials can be obtained by claim of a single ceramic thermal barrier coating (TBC) or several composite layers. Engine elements protected by TBC can work safely in elevated temperature range above 1000 degree C. Continuous endeavor to increase thermal resistance of engine the elements requires, apart from laboratory investigations, also numerical study of the different engine parts. The high temperatures and stress concentrations can act as the local sources of damage initiation and defects propagation in the form of cracks. The current study focuses the development of Yttria stabilized zirconia thermal barrier coating by Thermal spray technique. Mild steel was used as a substrate and the coating was then characterized for tribological analysis followed by the optical analysis of wear tracks and found the TBC behavior more promising then steel. (author)

Spin current and electrical polarization in GaN double-barrier structures

OpenAIRE

Litvinov, V. I.

2007-01-01

Tunnel spin polarization in a piezoelectric AlGaN/GaN double barrier structure is calculated. It is shown that the piezoelectric field and the spontaneous electrical polarization increase an efficiency of the tunnel spin injection. The relation between the electrical polarization and the spin orientation allows engineering a zero magnetic field spin injection manipulating the lattice-mismatch strain with an Al-content in the barriers.

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

Combined Thermomechanical and Environmental Durability of Environmental Barrier Coating Systems on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in next generation turbine engines for hot-section component applications. The development of prime-reliant environmental barrier coatings is essential to the EBC-CMC system durability, ensuring the successful implementations of the high temperature and lightweight engine component technologies for engine applications.This paper will emphasize recent NASA environmental barrier coating and CMC developments for SiC/SiC turbine airfoil components, utilizing advanced coating compositions and processing methods. The emphasis has been particularly placed on thermomechanical and environment durability evaluations of EBC-CMC systems. We have also addressed the integration of the EBCs with advanced SiC/SiC CMCs, and studied the effects of combustion environments and Calcium-Magnesium-Alumino-Silicate (CMAS) deposits on the durability of the EBC-CMC systems under thermal gradient and mechanical loading conditions. Advanced environmental barrier coating systems, including multicomponent rare earth silicate EBCs and HfO2-Si based bond coats, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

Functionally gradient materials for thermal barrier coatings in advanced gas turbine systems

Energy Technology Data Exchange (ETDEWEB)

Banovic, S.W.; Barmak, K.; Chan, H.M. [Lehigh Univ., Bethlehem, PA (United States)] [and others

1995-10-01

New designs for advanced gas turbine engines for power production are required to have higher operating temperatures in order to increase efficiency. However, elevated temperatures will increase the magnitude and severity of environmental degradation of critical turbine components (e.g. combustor parts, turbine blades, etc{hor_ellipsis}). To offset this problem, the usage of thermal barrier coatings (TBCs) has become popular by allowing an increase in maximum inlet temperatures for an operating engine. Although thermal barrier technology is over thirty years old, the principle failure mechanism is the spallation of the ceramic coating at or near the ceramic/bond coat interface. Therefore, it is desirable to develop a coating that combines the thermal barrier qualities of the ceramic layer and the corrosion protection by the metallic bond coat without the detrimental effects associated with the localization of the ceramic/metal interface to a single plane.

Regulatory barriers blocking standardization of interoperability.

Science.gov (United States)

Zhong, Daidi; Kirwan, Michael J; Duan, Xiaolian

2013-07-12

Developing and implementing a set of personal health device interoperability standards is key to cultivating a healthy global industry ecosystem. The standardization organizations, including the Institute of Electrical and Electronics Engineers 11073 Personal Health Device Workgroup (IEEE 11073-PHD WG) and Continua Health Alliance, are striving for this purpose. However, factors like the medial device regulation, health policy, and market reality have placed non-technical barriers over the adoption of technical standards throughout the industry. These barriers have significantly impaired the motivations of consumer device vendors who desire to enter the personal health market and the overall success of personal health industry ecosystem. In this paper, we present the affect that these barriers have placed on the health ecosystem. This requires immediate action from policy makers and other stakeholders. The current regulatory policy needs to be updated to reflect the reality and demand of consumer health industry. Our hope is that this paper will draw wide consensus amongst its readers, policy makers, and other stakeholders.

Reducing barriers to energy efficiency in the German energy service companies sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Koewener, D.; Schleich, J.

2000-12-01

This report describes the empirical research conducted in the German energy service sector to assess to what extent energy service companies (ESCOs) can help overcome the barriers to energy in the higher education, brewing and mechanical engineering sectors. This report complements the sector for Germany within the BARRIERS project (Sorrell et al., 2000; Schleich/Boede 2000a; Schleich/Boede 2000b; Schleich et al., 2000). The report characterises the German energy service sector, contains a description and analysis of four case studies in the energy service sector, identifies the main barriers and chances for ESCOs in the higher education, brewery and mechanical engineering sectors, and concludes with brief recommendations on how these barriers may be overcome. The results of the study are summarised here under the following headings: Characterising the energy service sector in Germany; - Case studies of energy service companies in Germany; - The role of ESCOs in the case-study sectors; - Policy implications. (orig.)

Automation U.S.A.: Overcoming Barriers to Automation.

Science.gov (United States)

Brody, Herb

1985-01-01

Although labor unions and inadequate technology play minor roles, the principal barrier to factory automation is "fear of change." Related problems include long-term benefits, nontechnical executives, and uncertainty of factory cost accounting. Industry support for university programs is helping to educate engineers to design, implement, and…

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

Tradition et innovations esthétiques dans la nouvelle yéménite contemporaine Tradition and aesthetic innovations in contemporary Yemeni short stories

Directory of Open Access Journals (Sweden)

Géraldine Jenvrin

2008-04-01

Full Text Available Le nouveau recueil de Mu/hammad ‘Abd al-Wakîl Jâzim témoigne d’une transformation capitale dans la littérature yéménite contemporaine :  le passage d’une forme expérimentale en rupture avec les règles de la nouvelle traditionnelle et avec la réalité yéménite, à une autre forme plus accomplie dans laquelle les principes traditionnels de la nouvelle sont ici associés sans complexe aux formes renouvelées du genre.  La nouvelle intitulée Le maître des vautours, présente, dans une structure narrative traditionnelle, un conte fantastique moderne qui mêle réalisme, symbolisme et poésie, et dans lequel l’auteur traite à sa manière les thèmes littéraires contemporains de la dualité du rêve et de la réalité, du désenchantement et de l’enfermement perpétuel.  C’est notamment en s’inspirant de la langue, des pratiques orales, des croyances et de l’imaginaire populaire, que l’auteur, soucieux de donner un ancrage au texte dans la réalité yéménite, transfigure cette expérience existentielle moderne.The latest collection of short stories by Mu/hammad 'Abd al-Wakîl signals a major shift in contemporary Yemeni literature: from an experimental form, breaking away from both traditional short story conventions and Yemeni reality, to another, more accomplished form, unabashedly mixing traditional short story principles with renewed genre forms. The short story entitled The Vulture Master presents us, from within a traditional narrative structure, with a modern fantasy tale blending in realism, symbolism and poetry, and where the writer deals in his own way with such contemporary literary themes as disenchantment, perpetual captivity, and the duality of dream and reality. Drawing his inspiration from language itself, oral practices, beliefs and popular imagery, the writer, seeking to set his tale firmly in Yemeni reality, manages to transfigure this modern existential experiment.

OFFICE OF SCIENCE AND TECHNOLOGY AND INTERNATIONAL, NATURAL BARRIERS THRUST OVERVIEW

International Nuclear Information System (INIS)

B. Bodvarsson; Y. Tsang

2006-01-01

The Natural Barriers Thrust supports scientific studies of the natural system at the proposed repository site of Yucca Mountain. It stresses the realistic representation of the natural system with respect to processes and parameters, by means of laboratory, field, and modeling studies. It has the objectives to demonstrate that the natural barriers can make large contributions to repository performance, supporting the multiple-barrier concept for geological disposal of high-level radioactive waste; and to reduce the overall cost of repository development by elimination of unnecessary engineered components, given the demonstrated natural barriers performance. In this overview we enumerate the research projects within the Natural Barriers Thrust grouped under five elements: (1) Drift Seepage, (2) In-drift Environment, (3) Drift Shadow, (4) Unsaturated Zone Flow and Transport, and (5) Saturated Zone Flow and Transport. The long-term strategic plan of the Natural Barriers Thrust and some key results are also briefly described

Acceptance test procedure for the 105-KW isolation barrier leak rate

International Nuclear Information System (INIS)

McCracken, K.J.

1995-01-01

This acceptance test procedure shall be used to: First establish a basin water loss rate prior to installation of the two isolation barriers between the main basin and the discharge chute in K-Basin West. Second, perform an acceptance test to verify an acceptable leakage rate through the barrier seals. This Acceptance Test Procedure (ATP) has been prepared in accordance with CM-6-1 EP 4.2, Standard Engineering Practices

Barrier analogs: Long-term performance issues, preliminary studies, and recommendations

Energy Technology Data Exchange (ETDEWEB)

Waugh, W.J. [Rust Geotech, Inc., Grand Junction, CO (United States). Environmental Sciences Lab.; Chatters, J.C.; Last, G.V.; Bjornstad, B.N.; Link, S.O. [Pacific Northwest Lab., Richland, WA (United States); Hunter, C.R. [Cascade Earth Sciences, La Grande, OR (United States)

1994-02-01

The US Department of Energy`s Hanford Protective Barrier Development Program is funding studies of natural analogs of the long-term performance of waste site covers. Natural-analog studies examine past environments as evidence for projecting the future performance of engineered structures. The information generated by analog studies is needed to (1) evaluate the designs and results of short term experiments and demonstrations, (2) formulate performance-modeling problems that bound expected changes in waste site environments, and (3) understand emergent system attributes that cannot be evaluated with short-term experiments or computer models. Waste site covers will be part of dynamic environmental systems with attributes that transcend the traits of engineered components. This report discusses results of the previously unreported preliminary studies conducted in 1983 and 1984. These results indicate that analogs could play an important role in predicting the long-term behavior of engineered waste covers. Layered exposures of glacial-flood-deposited gravels mantled with silt or sand that resemble contemporary barrier designs were examined. Bergmounds, another anomaly left by cataclysmic glacial floods, were also examined as analogs of surface gravel.

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)

The Transferability and Retraining of Defense Engineers.

Science.gov (United States)

Rittenhouse, Carl H.

This study was undertaken to describe any special barriers to the transfer of engineers from defense to commercial work, and to evaluate retraining and reorientation techniques that might help ease the transfer. Interviews and questionnaires were used to obtain data from about 2,100 engineers and 100 managers in 14 industries. Characteristics,…

Engineering students and their entrepreneurial intentions

Directory of Open Access Journals (Sweden)

Filipa Dionísio Vieira

2014-02-01

Full Text Available Promoting entrepreneurship is a key opportunity in the current environment, and engineering have recognized this criticism by including in their curricula basic financial disciplines. Given the current economic situation, provide the future engineer with concepts and techniques to move from knowledge to action, can improve the value perception of entrepreneurship as an alternative to employability on behalf of others. The aim of this paper is to present the preliminary results of the ENGEmpreende survey developed to measure the perceived attitudes and values of entrepreneurship by engineering students. Our sample involves 387 students of engineering courses from University of Minho. Portuguese engineering students report good levels of thoughts about entrepreneurship. Our study also found that their entrepreneurship predisposition has dependency relationships with gender, thoughts about entrepreneurship and entrepreneurial activities. The results of the perceived image of the entrepreneur suggest that students recognize the positive image of the entrepreneur in society, but have doubts about what is best: entrepreneur or employee in a large company? As perceived barriers, engineering students perceive as difficult to find a business idea or access to bank loans. Students’ perceived skills and competence suggest a perceived high adaptability, perseverance, technical confidence and orientation to results. The results of ENGEmpreende survey give an additional contribution to the theme of engineering entrepreneurship intentions through the identification of entrepreneurship predisposition, attitude to self-employment, entrepreneurial image, barriers to entrepreneurship, risk perception and technical confidence.

Coupled modelling (transport-reaction) of the fluid-clay interactions and their feed back on the physical properties of the bentonite engineered clay barrier system

International Nuclear Information System (INIS)

Marty, N.

2006-11-01

The originality of this work is to process feed back effects of mineralogical and chemical modifications of clays, in storage conditions, on their physical properties and therefore on their transport characteristics (porosity, molecular diffusion, permeability). These feed back effects are modelled using the KIRMAT code (Kinetic of Reaction and MAss Transfer) developed from the kinetic code KINDIS by adding the effect of water renewal in the mineral-solution reactive cells. KIRMAT resolves mass balance equations associated with mass transport together with the geochemical reactions in a 1D approach. After 100 000 years of simulated interaction at 100 C, with the fluid of the Callovo-Oxfordian geological level (COX) and with iron provided by the steel overpack corrosion, the montmorillonite of the clay barrier is only partially transformed (into illite, chlorite, saponite...). Only outer parts of the modelled profile seem to be significantly affected by smectite dissolution processes, mainly at the interface with the geological environment. The modifications of physical properties show a closure of the porosity at the boundaries of the barrier, by creating a decrease of mass transport by molecular diffusion, essentially at the interface with the iron. Permeability laws applied to this system show a decrease of the hydraulic conductivity correlated with the porosity evolution. Near the COX, the swelling pressure of the clays from the barrier decreases. In the major part of the modelled profile, the engineered clay barrier system seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure) and functionalities. (author)

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.)

Coping with the knowledge sharing barriers in Product Service Systems design

OpenAIRE

Bertoni, Marco; Larsson, Andreas

2010-01-01

This paper analyzes the knowledge sharing process that characterizes Product Service Systems (PSS) design, drawing on data from an in-depth study in the Swedish manufacturing industry. It categorizes and describes the most relevant knowledge sharing barriers affecting early PSS development phases, discussing them in terms of capabilities to be included in a knowledge engineering system to fulfil the increasing need for knowledge in product-service design. To cope with these barriers, the auth...

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...

Les théosophes et l’organisation internationale de l’éducation nouvelle (1911-1921

Directory of Open Access Journals (Sweden)

Sylvain Wagnon

2017-01-01

Full Text Available The historic importance of Theosophy within the realm of education is due to their presence in their reflexions and educational endeavours are at the origins of that nebulous movement called the New Education (éducation nouvelle. Their presence at the beginning of the organization of the New Education has been explored by several pioneering papers, but remains the blind spot in this area. In fact Theosophy’s influence has been felt but rarely analysed as the matrix of the nebulous international organization of new education. If the Theosophists’ influence were to be recognised, we think that their role, their persistent work that brought on not only the rise of new education, more specifically, the constitution of the International League of New Education but was also the making of educators of Theosophy teachings such as María Montessori and Rudolf Steiner who were not only the roots of the new education but also its main components.

[Biomedical engineering today : An overview from the viewpoint of the German Biomedical Engineering Society].

Science.gov (United States)

Schlötelburg, C; Becks, T; Stieglitz, T

2010-08-01

Biomedical engineering is characterized by the interdisciplinary co-operation of technology, science, and ways of thinking, probably more than any other technological area. The close interaction of engineering and information sciences with medicine and biology results in innovative products and methods, but also requires high standards for the interdisciplinary transfer of ideas into products for patients' benefits. This article describes the situation of biomedical engineering in Germany. It displays characteristics of the medical device industry and ranks it with respect to the international market. The research landscape is described as well as up-to-date research topics and trends. The national funding situation of research in biomedical engineering is reviewed and existing innovation barriers are discussed.

Calcium-Magnesium-Alumino-Silicates (CMAS) Reaction Mechanisms and Resistance of Advanced Turbine Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Costa, Gustavo; Harder, Bryan J.; Wiesner, Valerie L.; Hurst, Janet B.; Puleo, Bernadette J.

2017-01-01

Environmental barrier coatings (EBCs) and SiC/SiC ceramic matrix composites (CMCs) systems will play a crucial role in future turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is an essential requirement to enable the applications of the 2700-3000 F EBC - CMC systems. This presentation primarily focuses on the reaction mechanisms of advanced NASA environmental barrier coating systems, when in contact with Calcium-Magnesium Alumino-Silicates (CMAS) at high temperatures. Advanced oxide-silicate defect cluster environmental barrier coatings are being designed for ultimate balanced controls of the EBC temperature capability and CMAS reactivity, thus improving the CMAS resistance. Further CMAS mitigation strategies are also discussed.

Durability and Design Issues of Thermal/environmental Barrier Coatings on Sic/sic Ceramic Matrix Composites Under 1650 C Test Conditions

Science.gov (United States)

Zhu, Dong-Ming; Choi, Sung R.; Ghosn, Louis J.; Miller, Robert A.

2004-01-01

Ceramic thermal/environmental barrier coatings 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 durability remains a major concern with the ever-increasing temperature requirements. Currently, advanced T/EBC systems, which typically include a high temperature capable zirconia- (or hahia-) based oxide top coat (thermal barrier) on a less temperature capable mullite/barium-strontium-aluminosilicate (BSAS)/Si inner coat (environmental barrier), are being developed and tested for higher temperature capability Sic combustor applications. In this paper, durability of several thermal/environmental barrier coating systems on SiC/SiC ceramic matrix composites was investigated under laser simulated engine thermal gradient cyclic, and 1650 C (3000 F) test conditions. The coating cracking and delamination processes were monitored and evaluated. The effects of temperature gradients and coating configurations on the ceramic coating crack initiation and propagation were analyzed using finite element analysis (FEA) models based on the observed failure mechanisms, in conjunction with mechanical testing results. The environmental effects on the coating durability will be discussed. The coating design approach will also be presented.

Light Barrier for Non-Foil Packaging

Science.gov (United States)

2010-12-16

foil and all-plastic materials were retorted and a second set of all-plastic packaged entrees were Microwave Sterilized on the Washington State...Copolymers for Retort Applications; SPE Polyolefins and Flexible Packaging Conference: Society of Plastics Engineers. Newtown. CT, 43pp. Thellen C...Final Scientific Report Light Barrier for Non-Foil Packaging Contract No. W911QY-08-C-0132 Final Scientific Report Contract No. W911QY-08-C-0132

Regulatory Barriers Blocking Standardization of Interoperability

OpenAIRE

Zhong, Daidi; Kirwan, Michael J; Duan, Xiaolian

2013-01-01

Developing and implementing a set of personal health device interoperability standards is key to cultivating a healthy global industry ecosystem. The standardization organizations, including the Institute of Electrical and Electronics Engineers 11073 Personal Health Device Workgroup (IEEE 11073-PHD WG) and Continua Health Alliance, are striving for this purpose. However, factors like the medial device regulation, health policy, and market reality have placed non-technical barriers over the ad...

Nouvelle application de control des cavités 200 MHz RF du PS (CERN)

CERN Document Server

Cotte, D

2011-01-01

Le système Radio Fréquence (RF) 200MHz du PS est un outil essentiel pour la préparation des faisceaux haute intensité du PS. Dans l’anneau PS on trouve 6 cavités 200 MHz utilisées pour contrôler : • l’émittance longitudinale des « bunches » • le processus de « Rebunching » du faisceau avant de l’envoyer au SPS. Chaque cavité est pilotée par des événements appelés « timing » et suit une fonction de tension programmée. Cependant, l’électronique utilisée pour piloter les cavités 200 MHz du PS est obsolète et sa fiabilité non garantie pour cause du manque de pièces de rechange. Ce document décrit le fonctionnement du nouveau programme d’application qui fait abstraction de l’ancienne matrice hardware. Elle suit les recommandations décrites dans l’étude d’une nouvelle structure pour le système RF 200MHz du PS. [1

Biointrusion test plan for the Permanent Isolation Surface Barrier Prototype

International Nuclear Information System (INIS)

Link, S.O.; Cadwell, L.L.; Brandt, C.A.; Downs, J.L.; Rossi, R.E.; Gee, G.W.

1994-04-01

This document provides a testing and monitoring plan for the biological component of the prototype barrier slated for construction at the Hanford Site. The prototype barrier is an aboveground structure engineered to demonstrate the basic features of an earthen cover system. It is designed to permanently isolate waste from the biosphere. The features of the barrier include multiple layers of soil and rock materials and a low-permeability asphalt sublayer. The surface of the barrier consists of silt loam soil, covered with plants. The barrier sides are reinforced with rock or coarse earthen-fill to protect against wind and water erosion. The sublayers inhibit plant and animal intrusion and percolation of water. A series of tests will be conducted on the prototype barrier over the next several years to evaluate barrier performance under extreme climatic conditions. Plants and animals will play a significant role in the hydrologic and water and wind erosion characteristics of the prototype barrier. Studies on the biological component of the prototype barrier will include work on the initial revegetation of the surface, continued monitoring of the developing plant community, rooting depth and dispersion in the context of biointrusion potential, the role of plants in the hydrology of the surface and toe regions of the barrier, the role of plants in stabilizing the surface against water and wind erosion, and the role of burrowing animals in the hydrology and water and wind erosion of the barrier

FY2014 Advanced Combustion Engine Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None

2015-03-01

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

FY2016 Advanced Combustion Engine Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-07-01

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

FY2015 Advanced Combustion Engine Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

Singh, Gurpreet [Vehicle Technologies Office, Washington, DC (United States); Gravel, Roland M. [Vehicle Technologies Office, Washington, DC (United States); Howden, Kenneth C. [Vehicle Technologies Office, Washington, DC (United States); Breton, Leo [Vehicle Technologies Office, Washington, DC (United States)

2016-03-25

The Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies under development. Research focuses on addressing critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles.

Advanced Environmental Barrier Coating Development for SiC/SiC Ceramic Matrix Composites: NASA's Perspectives

Science.gov (United States)

Zhu, Dongming

2016-01-01

This presentation reviews NASA environmental barrier coating (EBC) system development programs and the coating materials evolutions for protecting the SiC/SiC Ceramic Matrix Composites in order to meet the next generation engine performance requirements. The presentation focuses on several generations of NASA EBC systems, EBC-CMC component system technologies for SiC/SiC ceramic matrix composite combustors and turbine airfoils, highlighting the temperature capability and durability improvements in simulated engine high heat flux, high pressure, high velocity, and with mechanical creep and fatigue loading conditions. The current EBC development emphasis is placed on advanced NASA 2700F candidate environmental barrier coating systems for SiC/SiC CMCs, their performance benefits and design limitations in long-term operation and combustion environments. Major technical barriers in developing environmental barrier coating systems, the coating integrations with next generation CMCs having the improved environmental stability, erosion-impact resistance, and long-term fatigue-environment system durability performance are described. The research and development opportunities for advanced turbine airfoil environmental barrier coating systems by utilizing improved compositions, state-of-the-art processing methods, and simulated environment testing and durability modeling are discussed.

Les nouvelles formes de la communication autour des projets urbains : modalités, impacts, enjeux pour un débat participatif

Directory of Open Access Journals (Sweden)

Hélène Bailleul

2008-09-01

Full Text Available Dans cet article, nous observons les évolutions que l’usage des nouvelles technologies implique dans la communication autour des projets urbains. Notre analyse des nouvelles modalités qu’Internet a pu importer dans la participation des habitants aux projets urbains (partie 1 nous pousse à observer, plus spécifiquement, les modifications qui ont trait, dans ce contexte, à la nature et au statut de l’information sur l’espace. La démocratisation des techniques de représentation de l’espace par ordinateur (3D, simulation entraîne le recours quasi systématique à des images virtuelles du projet, d’une grande qualité (partie 2, mais dont on ne connaît que très peu les impacts sur la perception et la réception que les habitants font du projet (partie 3.In this article, we observe the evolutions involved by the use of new technology in the communication around urban projects. Our analysis of the new modalities, Internet was able to import in the participation of inhabitants in urban projects (chapter 1 urges us to examine, more specifically, the modifications concerning the nature and the status of the information about space. The democratization of computer-based spatial representation’s tools (3D, simulation entails more and more systematic recourse to virtual images of the project, with high definition (chapter 2. But, nowadays, we still know little about their impacts on the perception and the reception, the inhabitants make of the project (chapter 3.

Waste package/engineered barrier system design concepts for the direct disposal of spent fuel in the potential United States' repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Stahl, D.; Harrison, D.J.

1993-01-01

The goal of the US Department of Energy's (DOE) Yucca Mountain Site Characterization Project (YMP) waste package development program is to design a waste package and associated engineered barrier system (EBS) that meets the applicable regulatory requirements for safe disposal of spent nuclear fuel and solidified high-level waste (HLW) in a geologic repository. Attainment of this goal relies on a multi-barrier approach, the unsaturated nature of the Yucca Mountain site, consideration of technical alternatives, and sufficient resolution of technical and regulatory uncertainties. To accomplish this, an iterative system engineering approach will be used. The NWPA of 1982 limits the content of the first US repository to 70,000 metric tons of heavy metal (MTHM). The DOE Mission Plan describes the implementation of the provisions of the NWPA for the waste management system. The Draft 1988 approach will involve selecting candidate designs, evaluating them against performance requirements, and then selecting one or two preferred designs for further detailed evaluation and final design. The reference design of the waste package described in the YMP Site Characterization Plan is a thin-walled, vertical borehole-emplaced waste package with an air gap between the package and the rock wall. The reference design appeared to meet the design requirement. However, the degree of uncertainty was large. This uncertainty led to considering several more-robust design concepts during the Advanced Conceptual Design phase of the program that include small, drift-emplaced packages and higher capacity, drift-emplaced packages, both partially and totally self-shielded. Metallic as well as ceramic materials are being considered

The development of permanent isolation barriers for buried wastes in cool deserts: Hanford, Washington

International Nuclear Information System (INIS)

Link, S.O.; Gee, G.W.; Wing, N.R.

1993-12-01

The purpose of this report is to present the results of research on surface hydrology and the role of plants and animals on permanent isolation barrier effectiveness at Hanford. These topics are a subset of a larger set of studies on permanent isolation barriers. A complete review of these tasks has been documented. We also discuss current work that tests our integrated scientific and engineering concepts on a large prototype barrier to determine if it can isolate buried wastes from environmental dispersion

NASA's Advanced Environmental Barrier Coatings Development for SiC/SiC Ceramic Matrix Composites: Understanding Calcium Magnesium Alumino-Silicate (CMAS) Degradations and Resistance

Science.gov (United States)

Zhu, Dongming

2014-01-01

Environmental barrier coatings (EBCs) and SiCSiC ceramic matrix composites (CMCs) systems will play a crucial role in next generation turbine engines for hot-section component applications because of their ability to significantly increase engine operating temperatures with improved efficiency, reduce engine weight and cooling requirements. The development of prime-reliant environmental barrier coatings is essential to the viability and reliability of the envisioned CMC engine component applications, ensuring integrated EBC-CMC system durability and designs are achievable for successful applications of the game-changing component technologies and lifing methodologies.This paper will emphasize recent NASA environmental barrier coating developments for SiCSiC turbine airfoil components, utilizing advanced coating compositions, state-of-the-art processing methods, and combined mechanical and environment testing and durability evaluations. The coating-CMC degradations in the engine fatigue-creep and operating environments are particularly complex; one of the important coating development aspects is to better understand engine environmental interactions and coating life debits, and we have particularly addressed the effect of Calcium-Magnesium-Alumino-Silicate (CMAS) from road sand or volcano-ash deposits on the durability of the environmental barrier coating systems, and how the temperature capability, stability and cyclic life of the candidate rare earth oxide and silicate coating systems will be impacted in the presence of the CMAS at high temperatures and under simulated heat flux conditions. Advanced environmental barrier coating systems, including HfO2-Si with rare earth dopant based bond coat systems, will be discussed for the performance improvements to achieve better temperature capability and CMAS resistance for future engine operating conditions.

THERMAL PROPERTIES OF TRANSPARENT BARRIER MODIFIED WITH ORGANIC PCMS

Directory of Open Access Journals (Sweden)

Michał MUSIAŁ

2016-03-01

Full Text Available Renewable energy sources are increasingly often applied in civil engineering as a mean to reduce buildings energy demand for heating. One of the ways to reduce HVAC energy demand is to limit heat transfer and excessive solar gain through building's glazed barriers. Preliminary results of the research conducted on organic PCM-modified transparent barrier are presented in this paper. Multiple publications concerning PCMs application in structural materials have recently appeared. Most of them are focused on modification of structure of non-transparent sections of buildings' envelope. Augmenting a glazed barrier with PCMs increases its heat capacity and thermal resistance. The most important feature of the assembly is the thermal buffer, a product of PCM's considerable value of specific latent heat. Research were conducted on a triple-pane transparent rectangular barrier, that constituted one of the faces of cubic chamber. Internal volume of the chamber was 1m3. The applied PCM was a mixture of saturated and non-saturated hydrocarbons. The described assembly was subjected to temperature and radiation that occur in Poland during winter. Glazing temperature, melted/total PCM ratio were measured, as well as energy demand for keeping internal temperature at constant level. Measurements were made in steady states, for various PCM layer thickness. The influence of the modification on energy demand was determined, along with the most effective and rational thickness of PCM layer to be applied. Conducted research enabled to develop a basis for further investigation of PCMs application in civil engineering.

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

Exhaust purification of DI spark ignition engines by means of barrier discharge. Final report; Abgasreinigung von DI-Ottomotoren durch Barrierenentladungen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Wolters, P.; Lepperhoff, G.; Baumgarten, H.; Scharr, D.; Neff, W.; Trompeter, F.J.; Seiwert, S.; Kamp, J.; Pochner, K.

2000-07-01

Dielectric barrier discharge offers the advantage to excite and dissociate molecules in the exhaust gas stream. Those dissociated and excited species are oxidizing or reducing harmful exhaust gas components. The advantage of a plasma chemical system in comparison to a catalytic converter is the instantaneous activity at ambient temperature from the turn key of the engine. The investigations presented here focus on the plasma chemical oxidation of hydrocarbons in the exhaust gas stream during cold start conditions. The article concerns the design and development of a plasma system in order to decrease the hydrocarbon emissions from engine start till catalyst light off. Vehicle results in the new European driving cycle show a hydrocarbon conversion of more than 43% in the first 11 seconds from engine start. In this period nearly all types of hydrocarbon were reduced. The exhaust back pressure of the sytem is comparable to the conventional muffler. Further system improvement can be achieved by an optimization of the disk electrode design. [German] Um die strengen zukuenftigen Schadstoffemissionsgrenzwerte von Ottomotoren in der EU oder den USA einhalten zu koennen, werden derzeit weltweit auch plasmachemische Methoden zur Abgasnachbehandlung in Betracht gezogen. Insbesondere nichtthermische Atmosphaerendruck-Gasentladungen, wie die Barrierenentladung, zeigen Chancen auf, die Betriebsbedingungen und Grenzen gegenwaertiger katalytischer Techniken zu erweitern. In diesem Vorhaben wurde die Barrierenentladung zur plasmachemischen Umsetzung von Schadstoffen im Abgas eines mager betriebenen Ottomotors im Serienautomobil untersucht, um das Potential zur Abgasreinigung zu bewerten und auszuweiten. (orig.)

A simulation study of moisture movement in proposed barriers for the subsurface disposal area, INEL

International Nuclear Information System (INIS)

Magnuson, S.O.

1993-09-01

This document presents a simulation study that was conducted to investigate moisture movement within two engineered barriers, which are proposed for use in eventual closure of the Subsurface Disposal Area. The results of the study are intended to guide the design and implementation of field test plots that will be constructed to test the barrier designs. Discussed are the sensitivity of barrier performance to changes in the conceptual model, which was used to simulate the barriers, and to changes in hydrologic parameters, which were used to describe the materials composing the barriers. In addition, estimates are presented concerning the time required for the moisture profile within the barriers to come into equilibrium with the meteorological conditions at the surface. In addition, the performance of the barriers under conditions of supplemental precipitation and ponding is presented

Spatially inhomogeneous barrier height in graphene/MoS2 Schottky junctions

Science.gov (United States)

Tomer, Dushyant; Rajput, Shivani; Li, Lian

Graphene interfaced with a semiconductor forms a Schottky junction with rectifying properties. In this study, graphene Schottky junctions are fabricated by transferring CVD monolayer graphene on mechanically exfoliated MoS2 multilayers. The forward bias current-voltage characteristics are measured in the temperature range of 210-300 K. An increase in the zero bias barrier height and decrease in the ideality factor are observed with increasing temperature. Such behavior is attributed to Schottky barrier inhomogeneities possibly due to graphene ripples and ridges at the junction interface as suggested by atomic force microscopy. Assuming a Gaussian distribution of the barrier height, mean barrier of 0.97+/-0.10 eV is found for the graphene MoS2 junction. Our findings provide significant insight on the barrier height inhomogeneities in graphene/two dimensional semiconductor Schottky junctions. U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering Award No. DEFG02-07ER46228.

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

Thermal Conductivity of Ceramic Thermal Barrier and Environmental Barrier Coating Materials

Science.gov (United States)

Zhu, Dong-Ming; Bansal, Narottam P.; Lee, Kang N.; Miller, Robert A.

2001-01-01

Thermal barrier and environmental barrier coatings (TBC's and EBC's) have been developed to protect metallic and Si-based ceramic components in gas turbine engines from high temperature attack. Zirconia-yttria based oxides and (Ba,Sr)Al2Si2O8(BSAS)/mullite based silicates have been used as the coating materials. In this study, thermal conductivity values of zirconia-yttria- and BSAS/mullite-based coating materials were determined at high temperatures using a steady-state laser heat flux technique. During the laser conductivity test, the specimen surface was heated by delivering uniformly distributed heat flux from a high power laser. One-dimensional steady-state heating was achieved by using thin disk specimen configuration (25.4 mm diam and 2 to 4 mm thickness) and the appropriate backside air-cooling. The temperature gradient across the specimen thickness was carefully measured by two surface and backside pyrometers. The thermal conductivity values were thus determined as a function of temperature based on the 1-D heat transfer equation. The radiation heat loss and laser absorption corrections of the materials were considered in the conductivity measurements. The effects of specimen porosity and sintering on measured conductivity values were also evaluated.

Aging and Phase Stability of Waste Package Outer Barrier

Energy Technology Data Exchange (ETDEWEB)

Tammy S. Edgecumble Summers

2001-08-23

This Analysis Model Report (AMR) was prepared in accordance with the Work Direction and Planning Document, ''Aging and Phase Stability of Waste Package Outer Barrier'' (CRWMS M&O 1999a). ICN 01 of this AMR was developed following guidelines provided in TWP-MGR-MD-000004 REV 01, ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001, Addendum B). It takes into consideration the Enhanced Design Alternative II (EDA II), which has been selected as the preferred design for the Engineered Barrier System (EBS) by the License Application Design Selection (LADS) program team (CRWMS M&O 1999b). The salient features of the EDA II design for this model are a waste package (WP) consisting of an outer barrier of Alloy 22 and an inner barrier of Type 316L stainless steel. This report provides information on the phase stability of Alloy 22l, the current waste-package-outer-barrier (WPOB) material. These phase stability studies are currently divided into three general areas: (1) Long-range order reactions; (2) Intermetallic and carbide precipitation in the base metal; and (3) Intermetallic and carbide precipitation in welded samples.

Next-Gen Search Engines

Science.gov (United States)

Gupta, Amardeep

2005-01-01

Current search engines--even the constantly surprising Google--seem unable to leap the next big barrier in search: the trillions of bytes of dynamically generated data created by individual web sites around the world, or what some researchers call the "deep web." The challenge now is not information overload, but information overlook.…

Strengthening engineering research and training in Africa

International Development Research Centre (IDRC) Digital Library (Canada)

Manfred Raffelsieper

2017-08-14

Aug 14, 2017 ... The engineering disciplines, in particular, could benefit from .... graduate education in Africa, with marked differences between ... particular attention to persistent structural barriers related to issues such as gender equality.

Vulnerability of multiple-barrier systems

International Nuclear Information System (INIS)

Lind, N.C.

1996-01-01

'Vulnerability' is defined as the ratio of the probability of failure of a damaged system to the probability of failure of the undamaged system. This definition applies to all engineered systems and can be specialized to particular system types. Some disastrous failures (e.g., Chernobyl) have shown that systems can be highly vulnerable. open-quotes Defense in depthclose quotes is a powerful design principle, reducing vulnerability when the consequences of failure can be catastrophic. In the nuclear industry, defense in depth is widely used in radiation protection, reactor control, and shutdown systems. A multiple-barrier system is a simple example of a system that has defense in depth. The idea is that the system is not vulnerable. It cannot fail if one barrier fails because there is another to take its place. This idea is untenable in waste management, but a quantified vulnerability of a system can help owners, designers, and regulators decide how much defense in depth is desirable or enough. Many multiple-barrier systems can be modeled as systems of components physically in a series, each individually able to prevent failure. Components typically have bimodal distributions of the service time to failure, as illustrated by an example of application to a hypothetical nuclear fuel waste repository

Greatest barrier is retaining young scientists

Science.gov (United States)

Chandler, Mark; Hopper, John

The National Science Foundation's top priorities as listed by director Neal Lane in Eos (November 9) are to strengthen NSF and its support of scientific research and education, to better articulate to the public why it is so important that support of science and engineering be strengthened, and to continue to lower barriers that discourage young people from choosing careers in science.While we firmly support the first two priorities, we are concerned about the underlying assumptions and implications of the third. Barriers discouraging women and minorities from considering careers in math and science do exist within our educational system, and there is now abundant statistical evidence showing these groups are under-represented in most fields of science. However, as stated in the Eos article, solving these problems and leveling the playing field is not the primary goal of the NSF policy.

The English Democrats Party ou l’émergence d’une nouvelle mouvance : le nationalisme autonomiste anglais

Directory of Open Access Journals (Sweden)

Claude BARBANTI

2011-03-01

Full Text Available La réforme dite de dévolution (décentralisation, votée en 1997, a entraîné de multiples conséquences et transformations dans la vie politique britannique. Le système traditionnellement unitaire de Westminster s’en est trouvé profondément bouleversé. Pourtant, tandis que de nombreuses études furent menées sur les divers nouveaux aspects d’une Grande-Bretagne dévolue, peu se sont penchées sur les conséquences de cette nouvelle asymétrie constitutionnelle sur l’Angleterre. Lorsque des députés de circonscriptions « celtiques » (en Écosse ou au pays de Galles arrivent à influencer le résultat de votes sur des affaires exclusivement anglaises, certains députés d’Angleterre, à Westminster, ne peuvent que se sentir désarmés face au manque de dispositions constitutionnelles garantissant un statut particulier pour ce territoire. Dès lors, de cette « question anglaise » (« English Question », naîtra toute une nouvelle mouvance autonomiste entièrement dédiée à l’obtention d’un Parlement anglais.Devolution at the end of the 1990s has led to numerous consequences and transformations in British politics. The traditional and centralised Westminster system has been turned upside down, and many studies have been carried out on the various aspects of this new “devolved Britain”.Yet, few have paid attention to the English case. However, the constitutional asymmetry thus created has indeed also affected England. When Celtic MPs succeed to influence the outcome of votes on exclusively English matters, one can realise that there is no such thing as an English government. Therefore, some English MPs have felt the need to ask for an option of “English Votes on English Laws”. This article tries to demonstrate that a feeling of “resentment” emerges from this situation and leads to the birth of a new “English” nationalism, entirely dedicated to obtaining an English Parliament.

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)

Barriers Against Adoption of Electronic Health Record in Italy

Directory of Open Access Journals (Sweden)

Stefano Bonacina

2011-01-01

Full Text Available This work aims to expose the barriers which work against the satisfactory adoption and utilization of Electronic Health Records (EHRs in Italy. Experts from six operating areas were involved where barriers associated with practical daily use of EHRs might arise. Experts disclosed different barriers in their operating areas: the low interoperability of healthcare system infrastructures in diagnostic services; the lack of systems able to represent complex processes characterized by uncertainties in hospital wards; the unsatisfactory information exchange between heterogeneous healthcare providers in territorial healthcare; the lack of models and guidelines for administration process management; the lack of Health Information engineers who are recognized as professionals in Italian hospitals; the lack of domain vocabularies and ontologies for conceptual integration in clinical communication. Our findings suggest how future solutions must be designed considering the environment of specific areas.

Thermal Gradient Cyclic Behavior of a Thermal/Environmental Barrier Coating System on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

Thermal barrier and environmental barrier coatings (TBCs and EBCs) will play a crucial role in future advanced gas turbine engines because of their ability to significantly extend the temperature capability of the ceramic matrix composite (CMC) engine components in harsh combustion environments. In order to develop high performance, robust coating systems for effective thermal and environmental protection of the engine components, appropriate test approaches for evaluating the critical coating properties must be established. In this paper, a laser high-heat-flux, thermal gradient approach for testing the coatings will be described. Thermal cyclic behavior of plasma-sprayed coating systems, consisting of ZrO2-8wt%Y2O3 thermal barrier and NASA Enabling Propulsion Materials (EPM) Program developed mullite+BSAS/Si type environmental barrier coatings on SiC/SiC ceramic matrix composites, was investigated under thermal gradients using the laser heat-flux rig in conjunction with the furnace thermal cyclic tests in water-vapor environments. The coating sintering and interface damage were assessed by monitoring the real-time thermal conductivity changes during the laser heat-flux tests and by examining the microstructural changes after the tests. The coating failure mechanisms are discussed based on the cyclic test results and are correlated to the sintering, creep, and thermal stress behavior under simulated engine temperature and heat flux conditions.

A Survey of Gender Biases of Freshman Students toward Engineering.

Science.gov (United States)

Schaer, Barbara; And Others

1991-01-01

A survey of 724 freshman engineering orientation students investigated the significance of 5 literature-cited barriers to women's success in engineering--sexual discrimination, financial concerns, academic comfort, career awareness, and locus of control. Significant main effects were found for gender but not ethnic group. The instrument is…

Charge transport through DNA based electronic barriers

Science.gov (United States)

Patil, Sunil R.; Chawda, Vivek; Qi, Jianqing; Anantram, M. P.; Sinha, Niraj

2018-05-01

We report charge transport in electronic 'barriers' constructed by sequence engineering in DNA. Considering the ionization potentials of Thymine-Adenine (AT) and Guanine-Cytosine (GC) base pairs, we treat AT as 'barriers'. The effect of DNA conformation (A and B form) on charge transport is also investigated. Particularly, the effect of width of 'barriers' on hole transport is investigated. Density functional theory (DFT) calculations are performed on energy minimized DNA structures to obtain the electronic Hamiltonian. The quantum transport calculations are performed using the Landauer-Buttiker framework. Our main findings are contrary to previous studies. We find that a longer A-DNA with more AT base pairs can conduct better than shorter A-DNA with a smaller number of AT base pairs. We also find that some sequences of A-DNA can conduct better than a corresponding B-DNA with the same sequence. The counterions mediated charge transport and long range interactions are speculated to be responsible for counter-intuitive length and AT content dependence of conductance of A-DNA.

Practical Application of Sociology in Systems Engineering

Science.gov (United States)

Watson, Michael D.; Andrews, James G.; Eckley, Jeri Cassel; Culver, Michael L.

2017-01-01

Systems engineering involves both the integration of the system and the integration of the disciplines which develop and operate the system. Integrating the disciplines is a sociological effort to bring together different groups, who often have different terminology, to achieve a common goal, the system. The focus for the systems engineer is information flow through the organization, between the disciplines, to ensure the system is developed and operated will all relevant information informing system decisions. The practical application of the sociology in systems engineering brings in various organizational development concepts including the principles of planned renegotiation and the application of principles to address information barriers created by organizational culture. Concepts such as specification of ignorance, consistent terminology, opportunity structures, role-sets, and the reclama (reconsideration) process are all important sociological approaches that help address the organizational social structure (culture). In bringing the disciplines together, the systems engineer must also be wary of social ambivalence, social anomie, social dysfunction, and insider-outsider behavior. Unintended consequences can result when these social issues are present. These issues can occur when localized subcultures shift from the overarching organizational culture, or when the organizational culture prevents achievement of system goals. These sociological principles provide the systems engineer with key approaches to manage the information flow through the organization as the disciplines are integrated and share their information and provides key sociological barriers to information flow through the organization. This paper will discuss the practical application of sociological principles to systems engineering.

The Cementitious Barriers Partnership (CBP) Software Toolbox Capabilities In Assessing The Degradation Of Cementitious Barriers

Energy Technology Data Exchange (ETDEWEB)

Flach, G. P. [Savannah River Site (SRS), Aiken, SC (United States); Burns, H. H. [Savannah River Site (SRS), Aiken, SC (United States); Langton, C. [Savannah River Site (SRS), Aiken, SC (United States); Smith, F. G. III [Savannah River Site (SRS), Aiken, SC (United States); Brown, K. G. [Vanderbilt University, Nashville, TN (United States); Kosson, D. S. [Vanderbilt University, Nashville, TN (United States); Garrabrants, A. C. [Vanderbilt University, Nashville, TN (United States); Sarkar, S. [Vanderbilt University, Nashville, TN (United States); van der Sloot, H. [Hans van der Sloot Consultancy (The Netherlands); Meeussen, J. C.L. [Nuclear Research and Consultancy Group, Petten (The Netherlands); Samson, E. [SIMCO Technologies Inc. , 1400, boul. du Parc - Technologique , Suite 203, Quebec (Canada); Mallick, P. [United States Department of Energy, 1000 Independence Ave. SW , Washington, DC (United States); Suttora, L. [United States Department of Energy, 1000 Independence Ave. SW , Washington, DC (United States); Esh, D. W. [U .S. Nuclear Regulatory Commission , Washington, DC (United States); Fuhrmann, M. J. [U .S. Nuclear Regulatory Commission , Washington, DC (United States); Philip, J. [U .S. Nuclear Regulatory Commission , Washington, DC (United States)

2013-01-11

The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the U.S. Department of Energy (US DOE) Office of Tank Waste and Nuclear Materials Management. The CBP program has developed a set of integrated tools (based on state-of-the-art models and leaching test methods) that help improve understanding and predictions of the long-term structural, hydraulic and chemical performance of cementitious barriers used in nuclear applications. Tools selected for and developed under this program have been used to evaluate and predict the behavior of cementitious barriers used in near-surface engineered waste disposal systems for periods of performance up to 100 years and longer for operating facilities and longer than 1000 years for waste disposal. The CBP Software Toolbox has produced tangible benefits to the DOE Performance Assessment (PA) community. A review of prior DOE PAs has provided a list of potential opportunities for improving cementitious barrier performance predictions through the use of the CBP software tools. These opportunities include: 1) impact of atmospheric exposure to concrete and grout before closure, such as accelerated slag and Tc-99 oxidation, 2) prediction of changes in Kd/mobility as a function of time that result from changing pH and redox conditions, 3) concrete degradation from rebar corrosion due to carbonation, 4) early age cracking from drying and/or thermal shrinkage and 5) degradation due to sulfate attack. The CBP has already had opportunity to provide near-term, tangible support to ongoing DOE-EM PAs such as the Savannah River Saltstone Disposal Facility (SDF) by providing a sulfate attack analysis that predicts the extent and damage that sulfate ingress will have on the concrete vaults over extended time (i.e., > 1000 years). This analysis is one of the many technical opportunities in cementitious barrier performance that can be addressed by the DOE-EM sponsored CBP software

Engineering materials for high level radioactive waste repository

International Nuclear Information System (INIS)

Wen Zhijian

2009-01-01

Radioactive wastes can arise from a wide range of human activities and have different physical and chemical forms with various radioactivity. The high level radioactive wastes (HLW)are characterized by nuclides of very high initial radioactivity, large thermal emissivity and the long life-term. The HLW disposal is highly concerned by the scientists and the public in the world. At present, the deep geological disposal is regarded as the most reasonable and effective way to safely dispose high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineering barrier system(EBS). The engineering materials in EBS include the vitrified HLW, canister, overpack, buffer materials and backfill materials. Referring to progress in the world, this paper presents the function, the requirement for material selection and design, and main scientific projects of R and D of engineering materials in HLW repository. (authors)

Une nouvelle orientation dans l’enseignement supérieur au vietnam: de la mémoire à la résolution de problèmes

Directory of Open Access Journals (Sweden)

TRƯƠNG Quang Dũng

2016-12-01

Full Text Available L’enseignement supérieur traditionnel est essentiellement basé sur la transmission du savoir et occasionnellement sur celle du savoir-faire. Il se réclame donc des disciplines universitaires (mathématiques, physique, chimie, géologie.... dispensées dans les universités et grandes écoles. Or, la réussite professionnelle et sociale dans le monde moderne exige d’autres acquis plus probants que des connaissances pures. Plusieurs recherches récentes ont ainsi montré que la résolution de bien des problèmes requiert des qualités pragmatiques d’efficacité indispensables pour l’accomplissement d’un travail créatif. Résoudre un problème revient alors à apprendre à maitriser une démarche méthodique composée de plusieurs phases, depuis l’identification du problème jusqu’à sa solution finale en passant par l’analyse judicieuse des causes. Il faut également maîtriser l’utilisation d’outils conceptuels et Méthodologiques tels que, entre autres, la « loi de Pareto », le questionnement systématique et le brainstorming . Au Vietnam on peut espérer la mise en application de ces nouvelles orientations dans un enseignement supérieur qui doit absolument se fixer comme objectif d’améliorer la qualité du travail social pour répondre aux nouvelles exigences de développement du pays.

Investigating the Language of Engineering Education

Science.gov (United States)

Variawa, Chirag

A significant part of professional communication development in engineering is the ability to learn and understand technical vocabulary. Mastering such vocabulary is often a desired learning outcome of engineering education. In promoting this goal, this research investigates the development of a tool that creates wordlists of characteristic discipline-specific vocabulary for a given course. These wordlists explicitly highlight requisite vocabulary learning and, when used as a teaching aid, can promote greater accessibility in the learning environment. Literature, including work in higher education, diversity and language learning, suggest that designing accessible learning environments can increase the quality of instruction and learning for all students. Studying the student/instructor interface using the framework of Universal Instructional Design identified vocabulary learning as an invisible barrier in engineering education. A preliminary investigation of this barrier suggested that students have difficulty assessing their understanding of technical vocabulary. Subsequently, computing word frequency on engineering course material was investigated as an approach for characterizing this barrier. However, it was concluded that a more nuanced method was necessary. This research program was built on previous work in the fields of linguistics and computer science, and lead to the design of an algorithm. The developed algorithm is based on a statistical technique called, Term Frequency-Inverse Document Frequency. Comparator sets of documents are used to hierarchically identify characteristic terms on a target document, such as course materials from a previous term of study. The approach draws on a standardized artifact of the engineering learning environment as its dataset; a repository of 2254 engineering final exams from the University of Toronto, to process the target material. After producing wordlists for ten courses, with the goal of highlighting characteristic

L'auteure mise en scène et mise à nu. Sur les fausses confessions de La nouvelle pornographie

Directory of Open Access Journals (Sweden)

Joëlle Papillon

2010-11-01

Full Text Available L'inclusion dans La nouvelle pornographie (2000 du nom propre de l'auteure est perçue comme une implication qui la met en danger. La métalepse est utilisée pour inscrire le roman dans la mouvance des confessions sexuelles et se jouer de leurs codes. Comme le discours publicitaire, Marie Nimier utilise la rhétorique pornographique afin de « vendre » un contenu domestique : la pornographie de surface dissimule un récit qui réinscrit l'amour comme moteur du désir féminin. Nimier joue de la métalepse pour déjouer les scènes pornographiques et séduire le lecteur par l'intelligence de ses manipulations plutôt que par ses dévoilements.

Annotated bibliography of selected references on shoreline barrier island deposits with emphasis on Patrick Draw Field, Sweetwater County, Wyoming

Energy Technology Data Exchange (ETDEWEB)

Rawn-Schatzinger, V.; Schatzinger, R.A.

1993-07-01

This bibliography contains 290 annotated references on barrier island and associated depositional environments and reservoirs. It is not an exhaustive compilation of all references on the subject, but rather selected papers on barrier islands, and the depositional processes of formation. Papers that examine the morphology and internal architecture of barrier island deposits, exploration and development technologies are emphasized. Papers were selected that aid in understanding reservoir architecture and engineering technologies to help maximize recovery efficiency from barrier island oil reservoirs. Barrier islands from Wyoming, Montana and the Rocky Mountains basins are extensively covered.

Calcium-Magnesium-Aluminosilicate (CMAS) Infiltration and Cyclic Degradations of Thermal and Environmental Barrier Coatings in Thermal Gradients

Science.gov (United States)

Zhu, Dongming; Harder, Bryan; Smialek, Jim; Miller, Robert A.

2014-01-01

In a continuing effort to develop higher temperature capable turbine thermal barrier and environmental barrier coating systems, Calcium-Magnesium-Aluminosilicate (CMAS) resistance of the advanced coating systems needs to be evaluated and improved. This paper highlights some of NASA past high heat flux testing approaches for turbine thermal and environmental barrier coatings assessments in CMAS environments. One of our current emphases has been focused on the thermal barrier - environmental barrier coating composition and testing developments. The effort has included the CMAS infiltrations in high temperature and high heat flux turbine engine like conditions using advanced laser high heat flux rigs, and subsequently degradation studies in laser heat flux thermal gradient cyclic and isothermal furnace cyclic testing conditions. These heat flux CMAS infiltration and related coating durability testing are essential where appropriate CMAS melting, infiltration and coating-substrate temperature exposure temperature controls can be achieved, thus helping quantify the CMAS-coating interaction and degradation mechanisms. The CMAS work is also playing a critical role in advanced coating developments, by developing laboratory coating durability assessment methodologies in simulated turbine engine conditions and helping establish CMAS test standards in laboratory environments.

IFP Energies Nouvelles. 2014 Activity report - Innovating for energy

International Nuclear Information System (INIS)

2015-01-01

As part of the public-interest mission with which it has been tasked by the public authorities, IFP Energies Nouvelles (IFPEN) focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the emergence of a sustainable energy mix, - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. Despite the current economic environment, 2014 was a good year for IFPEN. In the field of renewable energies, major milestones were reached in two significant projects dedicated to the production of second generation biofuels in which IFPEN is very actively involved: processes developed in Futurol TM are already in the pre-marketing phase, while the construction of the two pilot units for the BioTfueL project has just been launched. In the field of ocean energies, IFPEN research has led to the first partnership agreements relating to floating wind turbines anchor technologies and command control systems for wind energy and wave energy conversion. In the transport sector, game-changing concepts are beginning to emerge, such as smart battery charging and a Rankine cycle system for an internal combustion engine transforming combustion heat into energy. In addition, IFPEN have joined forces with innovative SMEs to boost their research in the fields of electric power-trains and power electronics. Finally, IFPEN launched an eco-driving application that has proved extremely popular with the public. Turning now to oil and gas, IFPEN continued to expand its range of basin and reservoir simulation, modeling and characterization software, and it signed several contracts in the field of chemical enhanced recovery solutions with its EOR (Enhanced Oil Recovery) Alliance TM partners. IFPEN also developed new generations of high-performance catalysts and improved the conversion rate of its processes to enable refiners to convert increasingly heavy crudes and

Breaking down the barriers to commercialization of fuel cells in transportation through Government - industry R&D programs

Energy Technology Data Exchange (ETDEWEB)

Chalk, S.G. [Dept. of Energy, Washington, DC (United States); Venkateswaran, S.R. [Energetics, Inc., Columbia, MD (United States)

1996-12-31

PEM fuel cell technology is rapidly emerging as a viable propulsion alternative to the internal combustion engine. Fuel cells offer the advantages of low emissions, high efficiency, fuel flexibility, quiet and continuous operation, and modularity. Over the last decade, dramatic advances have been achieved in the performance and cost of PEM fuel cell technologies for automotive applications. However, significant technical barriers remain to making fuel cell propulsion systems viable alternatives to the internal combustion engine. This paper focuses on the progress achieved and remaining technical barriers while highlighting Government-industry R&D efforts that are accelerating fuel cell technology toward commercialization.

Adoption et retombées d'une nouvelle technologie de dépistage des infections à ERV en contexte hospitalier québécois

OpenAIRE

Attieh, Randa

2015-01-01

La « Polymerase Chain Reaction» (PCR) est une technologie moléculaire qui se veut performante pour détecter les entérocoques résistants à la vancomycine (ERV) en contexte hospitalier. La traduction de cette technologie dans les pratiques professionnelles des acteurs est conceptualisée comme un processus d’adaptation et d’ajustements des rôles entre la technologie et le milieu hospitalier. Par souci de mieux comprendre la traduction de la nouvelle technologie de dépistage PCR dans les pratique...

Vision 2020. Reaction Engineering Roadmap

Energy Technology Data Exchange (ETDEWEB)

Klipstein, David H. [Reaction Design, San Diego, CA (United States); Robinson, Sharon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2001-01-01

The Reaction Engineering Roadmap is a part of an industry- wide effort to create a blueprint of the research and technology milestones that are necessary to achieve longterm industry goals. This report documents the results of a workshop focused on the research needs, technology barriers, and priorities of the chemical industry as they relate to reaction engineering viewed first by industrial use (basic chemicals; specialty chemicals; pharmaceuticals; and polymers) and then by technology segment (reactor system selection, design, and scale-up; chemical mechanism development and property estimation; dealing with catalysis; and new, nonstandard reactor types).

The Cementitious Barriers Partnership (CBP) Software Toolbox Capabilities in Assessing the Degradation of Cementitious Barriers - 13487

Energy Technology Data Exchange (ETDEWEB)

Flach, G.P.; Burns, H.H.; Langton, C.; Smith, F.G. III [Savannah River National Laboratory, Savannah River Site, Aiken SC 29808 (United States); Brown, K.G.; Kosson, D.S.; Garrabrants, A.C.; Sarkar, S. [Vanderbilt University, Nashville, TN (United States); Van der Sloot, H. [Hans Van der Sloot Consultancy (Netherlands); Meeussen, J.C.L. [Nuclear Research and Consultancy Group, Petten (Netherlands); Samson, E. [SIMCO Technologies Inc., 1400, boul. du Parc-Technologique, Suite 203, Quebec (Canada); Mallick, P.; Suttora, L. [United States Department of Energy, 1000 Independence Ave. SW, Washington, DC (United States); Esh, D.W.; Fuhrmann, M.J.; Philip, J. [U.S. Nuclear Regulatory Commission, Washington, DC (United States)

2013-07-01

The Cementitious Barriers Partnership (CBP) Project is a multi-disciplinary, multi-institutional collaboration supported by the U.S. Department of Energy (US DOE) Office of Tank Waste and Nuclear Materials Management. The CBP program has developed a set of integrated tools (based on state-of-the-art models and leaching test methods) that help improve understanding and predictions of the long-term structural, hydraulic and chemical performance of cementitious barriers used in nuclear applications. Tools selected for and developed under this program have been used to evaluate and predict the behavior of cementitious barriers used in near-surface engineered waste disposal systems for periods of performance up to 100 years and longer for operating facilities and longer than 1000 years for waste disposal. The CBP Software Toolbox has produced tangible benefits to the DOE Performance Assessment (PA) community. A review of prior DOE PAs has provided a list of potential opportunities for improving cementitious barrier performance predictions through the use of the CBP software tools. These opportunities include: 1) impact of atmospheric exposure to concrete and grout before closure, such as accelerated slag and Tc-99 oxidation, 2) prediction of changes in K{sub d}/mobility as a function of time that result from changing pH and redox conditions, 3) concrete degradation from rebar corrosion due to carbonation, 4) early age cracking from drying and/or thermal shrinkage and 5) degradation due to sulfate attack. The CBP has already had opportunity to provide near-term, tangible support to ongoing DOE-EM PAs such as the Savannah River Saltstone Disposal Facility (SDF) by providing a sulfate attack analysis that predicts the extent and damage that sulfate ingress will have on the concrete vaults over extended time (i.e., > 1000 years). This analysis is one of the many technical opportunities in cementitious barrier performance that can be addressed by the DOE-EM sponsored CBP

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

Opportunities and barriers to straw construction

DEFF Research Database (Denmark)

White, Caroline Meyer; Howard, Thomas J.; Lenau, Torben Anker

2012-01-01

produced to support communication between clients and the consultants and facilitate the straw build design and decision making process. The intended audiences for the design guide are clients of small scale construction projects, architects, engineers, builders of straw construction, homeowner...... construction, and a series of qualitative interviews with a variety of stakeholders from previous straw build housing projects, results were gathered to find the most influential motives, barriers and considerations for straw build housing construction. Based on this empirical data, a design guide has been...

Hanford Site Long-term Surface Barrier Development Program: Fiscal year 1994 highlights

International Nuclear Information System (INIS)

Petersen, K.L.; Link, S.O.; Gee, G.W.

1995-08-01

The Hanford Site Surface Barrier Development Program was organized in 1985 to test the effectiveness of various barrier designs in minimizing the effects of water infiltration; plant, animal and human intrusion; and wind and water erosion on buried wastes, plus preventing or minimizing the emanation of noxious gases. A team of scientists from the Pacific Northwest Laboratory (PNL) and engineers from Westinghouse Hanford Company (WHC) direct the barrier development effort. ICF Kaiser Hanford Company, in conjunction with WHC and PNL, developed design drawings and construction specifications for a 5-acre prototype barrier. The highlight of efforts in FY 1994 was the construction of the prototype barrier. The prototype barrier was constructed on the Hanford Site at the 200 BP-1 Operable Unit of the 200 East Area. Construction was completed in August 1994 and monitoring instruments are being installed so experiments on the prototype barrier can begin in FY 1995. The purpose of the prototype barrier is to provide insights and experience with issues regarding barrier design, construction, and performance that have not been possible with individual tests and experiments conducted to date. Additional knowledge and experience was gained in FY 1994 on erosion control, physical stability, water infiltration control, model testing, Resource Conservation and Recovery Act (RCRA) comparisons, biointrusion control, long-term performance, and technology transfer

Confirmation tests of construction method and initial performance quality for low permeable engineered barrier in side part of radioactive waste disposal facilities

International Nuclear Information System (INIS)

Yamada, Atsuo; Chijimatsu, Masakazu; Akiyama, Yoshihiro; Komine, Hideo; Iizuka, Atsushi

2016-01-01

As for the low permeable layer, important functions are expected as an engineered barrier of radioactive waste disposal for low-level waste with comparatively high radiation levels. On examining the construction methods of this low permeable layer, it is important to confirm the possibility of the construction in the conditions similar to the actual constructed conditions with a true scale size. Therefore, the construction examination for the side part of the low permeable layer by bentonite and the performance check test of the low permeable layer were carried out. The result of the construction examination showed that the possibility of the construction were confirmed, and the result of performance check test showed that it was possible to ensure the required performance of the low permeable layer, such as hydraulic conductivity. (author)

Thermal barrier coatings issues in advanced land-based gas turbines

Science.gov (United States)

Parks, W. P.; Lee, W. Y.; Wright, I. G.

1995-01-01

The Department of Energy's Advanced Turbine System (ATS) program is aimed at forecasting the development of a new generation of land-based gas turbine systems with overall efficiencies significantly beyond those of current state-of-the-art machines, as well as greatly increased times between inspection and refurbishment, improved environmental impact, and decreased cost. The proposed duty cycle of ATS turbines will require the use of different criteria in the design of the materials for the critical hot gas path components. In particular, thermal barrier coatings will be an essential feature of the hot gas path components in these machines. While such coatings are routinely used in high-performance aircraft engines and are becoming established in land-based turbines, the requirements of the ATS turbine application are sufficiently different that significant improvements in thermal barrier coating technology will be necessary. In particular, it appears that thermal barrier coatings will have to function on all airfoil sections of the first stage vanes and blades to provide the significant temperature reduction required. In contrast, such coatings applied to the blades and vances of advanced aircraft engines are intended primarily to reduce air cooling requirements and extend component lifetime; failure of those coatings can be tolerated without jeopardizing mechanical or corrosion performance. A major difference is that in ATS turbines these components will be totally reliant on thermal barrier coatings which will, therefore, need to be highly reliable even over the leading edges of first stage blades. Obviously, the ATS program provides a very challenging opportunity for TBC's, and involves some significant opportunities to extend this technology.

New method of determining the thermal utilization factor of a cell; Nouvelle methode de determination du facteur d'utilisation thermique d'une cellule

Energy Technology Data Exchange (ETDEWEB)

Amouyal, A; Benoist, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

A new formula for the thermal utilization factor is derived, which, while comparable in simplicity to the formula given by elementary diffusion theory, furnishes much more precise results. This is clearly brought out by comparison with the results given by the S{sub n} and spherical harmonics methods. (author) [French] Une nouvelle expression du facteur d'utilisation thermique, d'une simplicite comparable a celle de Ia theorie elementaire, est etablie. La comparaison avec les resultats fournis par la methode S{sub n} et les methodes d'harmoniques spheriques montre que la precision obtenue par cette formule est tres superieure a celle que donne la theorie elementaire. (auteur)

Développement des compétences interprofessionnelles de la nouvelle infirmière diplômée: revue de littérature

OpenAIRE

Meyer, Agnès,; Hauser, Christine,; Bulliard Verville, Danielle

2017-01-01

La pénurie infirmière qui touche actuellement la Suisse sera comblée en grande partie par les nouvelles diplômées infirmières1, d’ici quelques années. Cependant, un taux important de turnover dans les équipes peut mettre en péril leur encadrement. Leur processus d’insertion étant particulièrement éprouvant dans les premiers mois de pratique, il en résulte que nombre d’entre elles quittent précocement la profession. Comme stratégie pour pallier ce problème, la littérature montre les effets pos...

Schottky barriers based on metal nanoparticles deposited on InP epitaxial layers

Czech Academy of Sciences Publication Activity Database

Grym, Jan; Yatskiv, Roman

2013-01-01

Roč. 28, č. 4 (2013) ISSN 0268-1242 R&D Projects: GA MŠk LD12014 Institutional support: RVO:67985882 Keywords : Colloidal graphite * Epitaxial growth * Schottky barrier diodes Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.206, year: 2013

Standard practice for prediction of the long-term behavior of materials, including waste forms, used in engineered barrier systems (EBS) for geological disposal of high-level radioactive waste

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 This practice describes test methods and data analyses used to develop models for the prediction of the long-term behavior of materials, such as engineered barrier system (EBS) materials and waste forms, used in the geologic disposal of spent nuclear fuel (SNF) and other high-level nuclear waste in a geologic repository. The alteration behavior of waste form and EBS materials is important because it affects the retention of radionuclides by the disposal system. The waste form and EBS materials provide a barrier to release either directly (as in the case of waste forms in which the radionuclides are initially immobilized), or indirectly (as in the case of containment materials that restrict the ingress of groundwater or the egress of radionuclides that are released as the waste forms and EBS materials degrade). 1.1.1 Steps involved in making such predictions include problem definition, testing, modeling, and model confirmation. 1.1.2 The predictions are based on models derived from theoretical considerat...

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

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.

The development of surface barriers at the Hanford Site

International Nuclear Information System (INIS)

Wing, N.R.; Gee, G.W.

1994-03-01

Engineered barriers are being developed to isolate wastes disposed of near the earth's surface at the US Department of Energy's (DOE) Hanford Site near Richland, Washington. Much of the waste that would be disposed of by in-place stabilization currently is located in relatively shallow subsurface structures such as solid waste burial grounds, tanks, vaults, and cribs. Unless protected in some way, the wastes could be transported to the accessible environment via the following pathways: plant, animal, and human intrusion; water infiltration; erosion; and the exhalation of noxious gases. Permanent isolation surface barriers have been proposed to protect wastes disposed of ''in place'' from the transport pathways identified previously (Figure 1). The protective barrier consists of a variety of different materials (e.g., fine soil, sand, gravel, riprap, asphalt, etc.) placed in layers to form an above-grade mound directly over the waste zone. Surface markers are being considered for placement around the periphery of the waste sites to inform future generations of the nature and hazards of the buried wastes. In addition, throughout the protective barrier, subsurface markers could be placed to warn any inadvertent human intruders of the dangers of the buried wastes (Figure 2)

On the performance of capillary barriers as landfill cover

Science.gov (United States)

Kämpf, M.; Montenegro, H.

Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m). In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

On the performance of capillary barriers as landfill cover

Directory of Open Access Journals (Sweden)

M. Kämpf

1997-01-01

Full Text Available Landfills and waste heaps require an engineered surface cover upon closure. The capping system can vary from a simple soil cover to multiple layers of earth and geosynthetic materials. Conventional design features a compacted soil layer, which suffers from drying out and cracking, as well as root and animal intrusion. Capillary barriers consisting of inclined fine-over-coarse soil layers are investigated as an alternative cover system. Under unsaturated conditions, the textural contrast delays vertical drainage by capillary forces. The moisture that builds up above the contact will flow downdip along the interface of the layers. Theoretical studies of capillary barriers have identified the hydraulic properties of the layers, the inclination angle, the length of the field and the infiltration rate as the fundamental characteristics of the system. However, it is unclear how these findings can lead to design criteria for capillary barriers. To assess the uncertainty involved in such approaches, experiments have been carried out in a 8 m long flume and on large scale test sites (40 m x 15 m. In addition, the ability of a numerical model to represent the relevant flow processes in capillary barriers has been examined.

USE OF PERFLUOROCARBON TRACER (PFT) TECHNOLOGY FOR SUBSURFACE BARRIER INTEGRITY VERIFICATION AT THE WALDO TEST SITE

Energy Technology Data Exchange (ETDEWEB)

SULLIVAN,T.; HEISER,J.; SENUM,G.; MILLIAN,L.

2000-02-27

Researchers from Brookhaven National Laboratory (BNL) tested perfluorocarbon (PFT) gas tracers on a subsurface barrier with known flaws at the Waldo test facility [operated by Science and Engineering Associates, Inc (SEA)]. The tests involved the use of five unique PFT tracers with a different tracer injected along the interior of each wall of the barrier. A fifth tracer was injected exterior to the barrier to examine the validity of diffusion controlled transport of the PFTs. The PFTs were injected for three days at a nominal flow rate of 15 cm{sup 3}/min and a concentrations in the range of a few hundred ppm. Approximately 65 liters of air laced with tracer was injected for each tracer. The tracers were able to accurately detect the presence of the engineered flaws. Two flaws were detected on the north and east walls and lane flaw was detected on the south and west walls. In addition, one non-engineered flaw at the seam between the north and east walls was also detected. The use of multiple tracers provided independent confirmation of the flaws and permitted a distinction between tracers arriving at a monitoring port after being released from a nearby flaw and non-engineered flaws. The PFTs detected the smallest flaw, 0.5 inches in diameter. Visual inspection of the data showed excellent agreement with the known flaw locations and the relative size of the flaws was accurately estimated.

Neurophysiology and neural engineering: a review.

Science.gov (United States)

Prochazka, Arthur

2017-08-01

Neurophysiology is the branch of physiology concerned with understanding the function of neural systems. Neural engineering (also known as neuroengineering) is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties and functions of neural systems. In most cases neural engineering involves the development of an interface between electronic devices and living neural tissue. This review describes the origins of neural engineering, the explosive development of methods and devices commencing in the late 1950s, and the present-day devices that have resulted. The barriers to interfacing electronic devices with living neural tissues are many and varied, and consequently there have been numerous stops and starts along the way. Representative examples are discussed. None of this could have happened without a basic understanding of the relevant neurophysiology. I also consider examples of how neural engineering is repaying the debt to basic neurophysiology with new knowledge and insight. Copyright © 2017 the American Physiological Society.

Delay time and Hartman effect in strain engineered graphene

International Nuclear Information System (INIS)

Chen, Xi; Deng, Zhi-Yong; Ban, Yue

2014-01-01

Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect

Integrating ergonomic knowledge into engineering design processes

DEFF Research Database (Denmark)

Hall-Andersen, Lene Bjerg

Integrating ergonomic knowledge into engineering design processes has been shown to contribute to healthy and effective designs of workplaces. However, it is also well-recognized that, in practice, ergonomists often have difficulties gaining access to and impacting engineering design processes...... employed in the same company, constituted a supporting factor for the possibilities to integrate ergonomic knowledge into the engineering design processes. However, the integration activities remained discrete and only happened in some of the design projects. A major barrier was related to the business...... to the ergonomic ambitions of the clients. The ergonomists’ ability to navigate, act strategically, and compromise on ergonomic inputs is also important in relation to having an impact in the engineering design processes. Familiarity with the engineering design terminology and the setup of design projects seems...

Aptamer nanomedicine for cancer therapeutics: barriers and potential for translation.

Science.gov (United States)

Lao, Yeh-Hsing; Phua, Kyle K L; Leong, Kam W

2015-03-24

Aptamer nanomedicine, including therapeutic aptamers and aptamer nanocomplexes, is beginning to fulfill its potential in both clinical trials and preclinical studies. Especially in oncology, aptamer nanomedicine may perform better than conventional or antibody-based chemotherapeutics due to specificity compared to the former and stability compared to the latter. Many proof-of-concept studies on applying aptamers to drug delivery, gene therapy, and cancer imaging have shown promising efficacy and impressive safety in vivo toward translation. Yet, there remains ample room for improvement and critical barriers to be addressed. In this review, we will first introduce the recent progress in clinical trials of aptamer nanomedicine, followed by a discussion of the barriers at the design and in vivo application stages. We will then highlight recent advances and engineering strategies proposed to tackle these barriers. Aptamer cancer nanomedicine has the potential to address one of the most important healthcare issues of the society.

Nearfield behaviour of clay barriers and their interaction with concrete Task 3 characterization of radioactive waste forms a series of final reports (1985-89) No 26

International Nuclear Information System (INIS)

Atabek, R.; Beziat, A.; Coulon, H.; Dardaine, M.; Eglem, A.; Farcy, C.; Fontan, N.; Gatabin, C.; Gegout, P.; Lajudie, A.; Landoas, O.; Lechelle, J.; Plas, F.; Raynal, J.; Revertegat, E.; Debrabant, P.; Proust, D.

1991-01-01

In order to guarantee the safety of waste underground disposal, engineered barriers will be implemented as backfill materials in galleries and access shafts and as buffer materials between the host medium and the waste packages. One of the first requirements for engineered barriers is to minimize water and chemical species transfer. The materials being considered are essentially swelling clays, in particular calcium smectite clays coming from french deposits and hydraulic binders, more specially a ternary cement (named C.L.C.). A vitrified waste disposal in granite is taken as the most constraining scenario as far as engineered barrier is concerned. The clay buffer material is placed between the packages and the host rock. The main properties which are determined are directly related to the engineered barrier requirements: thermal conductivity, hydraulic conductivity, swelling pressure and swelling capacity. Moreover results are obtained on temperature effect on clay microstructure and properties in both cases: without and with water intake. The concrete durability with regard to clay pore water attack is evaluated taking into account previous results obtained to ensure low-level radioactive waste disposal safety. 23 refs., 29 figs., 10 tabs

Sprache als Barriere (Language as a Barrier)

Science.gov (United States)

Mattheier, Klaus

1974-01-01

The concept of language barrier has its derivations in the fields of dialectology, sociology and psychology. In contemporary usage however, the concept has two meanings i.e. regional-cultural barrier and socio-cultural barrier. (Text is in German.) (DS)

FY2011 Annual Progress Report for Advanced Combustion Engine Research and Development

Energy Technology Data Exchange (ETDEWEB)

none,

2011-12-01

Annual Progress Report for the Advanced Combustion Engine Research and Development (R&D) subprogram supporting the mission of the Vehicle Technologies Program by removing the critical technical barriers to commercialization of advanced internal combustion engines (ICEs) for passenger and commercial vehicles that meet future federal emissions regulations.

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.

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

The in-situ vitrification of subsurface containment barriers: An overview

International Nuclear Information System (INIS)

Murphy, M.; Stottlemyre, J.A.

1990-11-01

In situ vitrification (ISV) is an environmental engineering process in which soil or soil/waste mixtures are melted through the direct application of electrical current and subsequently cooled to a glassy solid. The technology was developed by Pacific Northwest Laboratory (PNL) in the 1980s and has been tested on transuranic, mixed-hazardous, and PCB/organic waste similar to that found at US Department of Energy (DOE) and other facilities nationwide. PNL is conducting a wide range of field tests, expanding the scientific basis of ISV, and assessing its extension into new applications. One such project is ISV--Selective Barriers, an investigation into the construction and performance of ISV--generated, vertical and/or horizontal subsurface barriers to ground-water flow and biogenic intrusion. In some situations, it may be impractical or unnecessary to either excavate or vitrify an entire waste site. Vitrified barriers could minimize the diffusive or fluid transport of hazardous components with either a ground-water diversion wall or an in situ, ''box-like'' structure. During the first year of this project, engineering-scale tests are being conducted between graphite electrodes within a 1.8-m-diameter, 2.4-m-high test cell. Several methods are being tested, including passive metal electrodes, electrode feeding systems, fluxed soil, and fluxed boreholes. In addition, basic data have been collected on the thermal and material properties of ISV melt and solidified glass. 7 refs., 6 figs

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…

A new approach to performance assessment of barriers in a repository. Executive summary, draft, technical appendices. Final report

International Nuclear Information System (INIS)

Mueller-Hoeppe, N.; Krone, J.; Niehues, N.; Poehler, M.; Raitz von Frentz, R.; Gauglitz, R.

1999-06-01

Multi-barrier systems are accepted as the basic approach for long term environmental safe isolation of radioactive waste in geological repositories. Assessing the performance of natural and engineered barriers is one of the major difficulties in producing evidence of environmental safety for any radioactive waste disposal facility, due to the enormous complexity of scenarios and uncertainties to be considered. This report outlines a new methodological approach originally developed basically for a repository in salt, but that can be transferred with minor modifications to any other host rock formation. The approach is based on the integration of following elements: (1) Implementation of a simple method and efficient criteria to assess and prove the tightness of geological and engineered barriers; (2) Using the method of Partial Safety Factors in order to assess barrier performance at certain reasonable level of confidence; (3) Integration of a diverse geochemical barrier in the near field of waste emplacement limiting systematically the radiological consequences from any radionuclide release in safety investigations and (4) Risk based approach for the assessment of radionuclide releases. Indicative calculations performed with extremely conservative assumptions allow to exclude any radiological health consequences from a HLW repository in salt to a reference person with a safety level of 99,9999% per year. (orig.)

Barrier mechanisms in the Drosophila blood-brain barrier

Directory of Open Access Journals (Sweden)

Samantha Jane Hindle

2014-12-01

Full Text Available The invertebrate blood-brain barrier field is growing at a rapid pace and, in recent years, studies have shown a physiologic and molecular complexity that has begun to rival its vertebrate counterpart. Novel mechanisms of paracellular barrier maintenance through GPCR signaling were the first demonstrations of the complex adaptive mechanisms of barrier physiology. Building upon this work, the integrity of the invertebrate blood-brain barrier has recently been shown to require coordinated function of all layers of the compound barrier structure, analogous to signaling between the layers of the vertebrate neurovascular unit. These findings strengthen the notion that many blood-brain barrier mechanisms are conserved between vertebrates and invertebrates, and suggest that novel findings in invertebrate model organisms will have a significant impact on the understanding of vertebrate BBB functions. In this vein, important roles in coordinating localized and systemic signaling to dictate organism development and growth are beginning to show how the blood-brain barrier can govern whole animal physiologies. This includes novel functions of blood-brain barrier gap junctions in orchestrating synchronized neuroblast proliferation, and of blood-brain barrier secreted antagonists of insulin receptor signaling. These advancements and others are pushing the field forward in exciting new directions. In this review, we provide a synopsis of invertebrate blood-brain barrier anatomy and physiology, with a focus on insights from the past 5 years, and highlight important areas for future study.

Fire barrier evaluation of the wall between spent nuclear fuel storage basins and reactor areas, 105KE and 105KW

International Nuclear Information System (INIS)

Johnson, B.H.

1994-01-01

This evaluation is intended to provide a comprehensive assessment of the risks from fire and fire related perils for the fire barriers between spent nuclear fuel storage basins and reactor areas, 105KE and 105KW. As a result of this fire barrier evaluation the present walls and the components thereof are not a true listed fire rated assembly. However, due to the construction of these barriers and the components thereof, these barriers will provide an equivalent level of protection provided the recommendations in Section 8.0 of this report are completed. These recommended upgrades are based upon sound engineering practice by a Registered Fire Protection Engineer. The construction of the barrier are substantial enough to provide the required 2-hr fire resistance rating. The primary concern is the numerous penetrations in the barrier. There are many penetrations that are adequate and no additional work is required. These penetrations are the ones that were poured-in-place at the time of construction. The penetrations that are of concern are some of the doors, the HVAC ducts, and the unsealed piping and conduit penetrations. There are several metal doors that should be replaced because the existing doors have either a non-approved window or louver that will not limit the spread of fire to one side of the barrier. All unsealed piping and conduit penetrations should be firestopped with an approved firestopping material. The existing non-active ducts that pass through the barrier should be disconnected at the barrier and the opening sealed with an approved firestopping method

Barrier layer engineering: Performance evaluation of E-mode InGaN/AlGaN/GaN HEMT

Science.gov (United States)

Majumdar, Shubhankar; Das, S.; Biswas, D.

2015-08-01

Impact on DC characteristics of InGaN/AlGaN/GaN HEMT due to variation in the hetero-structure parameters i.e. molar fraction of Al and thickness of AlGaN barrier layer is presented in this paper. Gate controllability over the channel is dependent on barrier layer thickness, and molar fraction has an impact on band offset and 2DEG, which further affects the current. HEMT device that is simulated in SILVACO has InGaN cap layer of 2 nm thickness with 15% In molar fraction, variation of Al percentage and thickness of the AlGaN barrier layer are taken as 15-45% and 5-20nm, respectively. A tremendous change in threshold voltage (Vth), maximum transconductance (Gmmax) and subthreshold swing is found due to variation in hetero-structure parameter of barrier layer and the values are typically 1.3-0.1 V, 0.6-0.44 S/mm and 75-135 mV/dec respectively.

IMPROVING THE EFFECTIVENESS AND UTILISATION OF THE INDUSTRIAL ENGINEERING FUNCTION

Directory of Open Access Journals (Sweden)

Gordon Lister

2012-01-01

Full Text Available Research work carried out by the University of Cape Town has examined the following questions:
- are industrial engineering techniques being used in industry?
- what are the reasons for not using the various techniques?
- what factors that can be addressed by industrial engineers, are inhibiting the improvement of manufacturing productivity?
- are industrial engineers being utilised in the most effective t"ay? Investigations in South African and overseas companies have indicated some barriers to acceptance that have to be overcome. This paper identifies key elements which, if implemented or adopted, will improve the effectiveness of both industrial engineers, and the intrOduction of industrial engineering techniques.

Today's Yucca mountain project and a new concept of multi-barrier system

International Nuclear Information System (INIS)

Xu Guoqing

2008-01-01

This paper mainly deals with the current status of Yucca Mountain project and the progress in study on engineering barrier in Belgium and introduces the future plan for Yucca Mountain project, two reports on draft supplemental environmental impact statement, and the view of New York Sen. Hillary Clinton and Illinois Sen. Barack Obama during the 2008 president elections related to the building a nuclear waste repository in Nevada. In order to enhance the security of geological disposal of high-level radioactive waste, a new concept about multi-barrier system is given by Belgium and is concisely described here. (authors)

Hydrothermal alkaline stability of bentonite barrier by concrete interstitial wastes

International Nuclear Information System (INIS)

Leguey Jimenez, S.; Cuevas Rodriguez, J.; Ramirez Martin, S.; Vigil de la villa Mencia, R.; Martin Barca, M.

2002-01-01

At present, the main source of High Level radioactive Waste (HLW) is the electrical energy production during all the steps of developing. In almost all the countries with nuclear programs, the option for the final management of HLW is the Deep Geological Repository (DGR) based on the concept of multi barrier. According to this concept, the waste is isolated from biosphere by the interposition of confinement barriers. Two of the engineering barriers in the Spanish design of DGR in granitic rock are compacted bentonite and concrete. The bentonite barrier is the backfilling and sealing material for the repository gallery, because of its mechanical and physico-chemical properties. The main qualities of concrete as a component of a multi barrier system are its low permeability, mechanical resistance and chemical properties. With regard to chemical composition of concrete, the alkaline nature of cement pore water lowers the solubility of many radioactive elements. However, structural transformation in smectite, dissolution or precipitation of minerals and, consequently, changes in the bentonite properties could occurs in the alkaline conditions generated by the cement degradation. The main objective of the present work is to evaluate the effect of concrete in the stability of Spanish reference bentonite (La Serrata of Nijar, Almeria, Spain) in conditions similar to those estimated in a DGR in granitic rock. Because of the main role of bentonite barrier in the global performance of the repository, the present study is essential to guarantee its security. (Author)

Mapping Remote and Multidisciplinary Learning Barriers: Lessons from "Challenge-Based Innovation" at CERN

Science.gov (United States)

Jensen, Matilde Bisballe; Utriainen, Tuuli Maria; Steinert, Martin

2018-01-01

This paper presents the experienced difficulties of students participating in the multidisciplinary, remote collaborating engineering design course challenge-based innovation at CERN. This is with the aim to identify learning barriers and improve future learning experiences. We statistically analyse the rated differences between distinct design…

Quantitative performance allocation of multi-barrier system for high-level radioactive waste disposal

International Nuclear Information System (INIS)

Ahn, Joon-Hong; Ikeda, Takao; Ohe, Toshiaki

1995-01-01

Performance assessment of each barrier consisting of geologic disposal system for high-level radioactive wastes is carried out quantitatively, and key radionuclides and parameters are pointed out. Chemical compositions and solubilities of radionuclides under repository conditions are determined by PHREEQE code staring from compositions of granitic groundwater observed in Japan. Glass dissolution analysis based on mass transfer theory and precipitation analysis have been done in order to determine the inner boundary condition for radionuclide diffusion through a bentonite-filled buffer region, where multi-member decay chain and isotopic sharing of solubility at the inner boundary are considered. Natural barrier is treated as homogeneous porous rock, or porous rock with infinite planar fractures. Performance of each barrier is evaluated in terms of non-dimensionalized hazard defined as the ratio of annual radioactivity release from each barrier to the annual limit on intake. At the outer edge of the engineered barriers, 239 Pu is the key unclide to the performance, whereas at the exit of the natural barrier, weakly-sorbing fission product nuclides such as 135 Cs, 129 I and 99 Tc dominate the hazard. (author) 50 refs

Performance and Durability of Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

Science.gov (United States)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

This presentation highlights advanced environmental barrier coating (EBC) and SiC-SiC Ceramic Matrix Composites (CMC) systems for next generation turbine engines. The emphasis will be placed on fundamental coating and CMC property evaluations; and the integrated system performance and degradation mechanisms in simulated laboratory turbine engine testing environments. Long term durability tests in laser rig simulated high heat flux the rmomechanical creep and fatigue loading conditions will also be presented. The results can help improve the future EBC-CMC system designs, validating the advanced EBC-CMC technologies for hot section turbine engine applications.

200-BP-1 Prototype Hanford Barrier -- 15 Years of Performance Monitoring

Energy Technology Data Exchange (ETDEWEB)

Ward, Anderson L.; Draper, Kathryn E.; Link, Steven O.; Clayton, Ray E.

2011-09-30

Monitoring is an essential component of engineered barrier system design and operation. A composite capacitive cover, including a capillary break and an evapotranspiration (ET) barrier at the Hanford Site, is generating data that can be used to help resolve these issues. The prototype Hanford barrier was constructed over the 216-B-57 Crib in 1994 to evaluate surface-barrier constructability, construction costs, and physical and hydrologic performance at the field scale. The barrier has been routinely monitored between November 1994 and September 1998 as part of a Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) treatability test of barrier performance for the 200 BP 1 Operable Unit. Since FY 1998, monitoring has focused on a more limited set of key water balance, stability, and biotic parameters. In FY 2009, data collection was focused on: (1) water-balance monitoring, consisting of precipitation, runoff, soil moisture storage, and drainage measurements with evapotranspiration calculated by difference; (2) stability monitoring, consisting of asphalt-layer-settlement, basalt-side-slope-stability, and surface-elevation measurements; (3) vegetation dynamics; and (4) animal use. September 2009 marked 15 years since the start of monitoring and the collection of performance data. This report describes the results of monitoring activities during the period October 1, 2008, through September 30, 2009, and summarizes the 15 years of performance data collected from September 1994 through September 2009.

Coupled modelling (transport-reaction) of the fluid-clay interactions and their feed back on the physical properties of the bentonite engineered clay barrier system; Modelisation couplee (transport - reaction) des interactions fluides - argiles et de leurs effets en retour sur les proprietes physiques de barrieres ouvragees en bentonite

Energy Technology Data Exchange (ETDEWEB)

Marty, N

2006-11-15

The originality of this work is to process feed back effects of mineralogical and chemical modifications of clays, in storage conditions, on their physical properties and therefore on their transport characteristics (porosity, molecular diffusion, permeability). These feed back effects are modelled using the KIRMAT code (Kinetic of Reaction and MAss Transfer) developed from the kinetic code KINDIS by adding the effect of water renewal in the mineral-solution reactive cells. KIRMAT resolves mass balance equations associated with mass transport together with the geochemical reactions in a 1D approach. After 100 000 years of simulated interaction at 100 C, with the fluid of the Callovo-Oxfordian geological level (COX) and with iron provided by the steel overpack corrosion, the montmorillonite of the clay barrier is only partially transformed (into illite, chlorite, saponite...). Only outer parts of the modelled profile seem to be significantly affected by smectite dissolution processes, mainly at the interface with the geological environment. The modifications of physical properties show a closure of the porosity at the boundaries of the barrier, by creating a decrease of mass transport by molecular diffusion, essentially at the interface with the iron. Permeability laws applied to this system show a decrease of the hydraulic conductivity correlated with the porosity evolution. Near the COX, the swelling pressure of the clays from the barrier decreases. In the major part of the modelled profile, the engineered clay barrier system seems to keep its initial physical properties (porosity, molecular diffusion, permeability, swelling pressure) and functionalities. (author)

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

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

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.

Thermal Barrier Coatings Resistant to Glassy Deposits

Science.gov (United States)

Drexler, Julie Marie

Engineering of alloys has for years allowed aircraft turbine engines to become more efficient and operate at higher temperatures. As advancements in these alloy systems have become more difficult, ceramic thermal barrier coatings (TBCs), often yttria (7 wt %) stabilized zirconia (7YSZ), have been utilized for thermal protection. TBCs have allowed for higher engine operating temperatures and better fuel efficiency but have also created new engineering problems. Specifically, silica based particles such as sand and volcanic ash that enter the engine during operation form glassy deposits on the TBCs. These deposits can cause the current industrial 7YSZ thermal barrier coatings to fail since the glass formed penetrates and chemically interacts with the TBC. When this occurs, coating failure may occur due to a loss of strain tolerance, which can lead to fracture, and phase changes of the TBC material. There have been several approaches used to stop calcium-magnesium aluminio-silcate (CMAS) glasses (molten sand) from destroying the entire TBC, but overall there is still limited knowledge. In this thesis, 7YSZ and new TBC materials will be examined for thermochemical and thermomechanical performance in the presence of molten CMAS and volcanic ash. Two air plasma sprayed TBCs will be shown to be resistant to volcanic ash and CMAS. The first type of coating is a modified 7YSZ coating with 20 mol% Al2O3 and 5 mol% TiO2 in solid solution (YSZ+20Al+5Ti). The second TBC is made of gadolinium zirconate. These novel TBCs impede CMAS and ash penetration by interacting with the molten CMAS or ash and drastically changing the chemistry. The chemically modified CMAS or ash will crystallize into an apatite or anorthite phase, blocking the CMAS or ash from further destroying the coating. A presented mechanism study will show these coatings are effective due to the large amount of solute (Gd, Al) in the zirconia structure, which is the key to creating the crystalline apatite or

Aerodynamic and aeroelastic characteristics of typical bridge decks equipped with wind barriers at the windward bridge-deck edge

Czech Academy of Sciences Publication Activity Database

Buljac, Andrija; Kozmar, H.; Pospíšil, Stanislav; Macháček, Michael

2017-01-01

Roč. 137, April (2017), s. 310-322 ISSN 0141-0296 R&D Projects: GA ČR(CZ) GA15-01035S; GA MŠk(CZ) LO1219 Keywords : bridge decks * roadway wind barrier * aerodynamic forces and moments * galloping * flutter * wind-tunnel experiments Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering , Municipal and structural engineering Impact factor: 2.258, year: 2016 http://www.sciencedirect.com/science/ article /pii/S014102961730278X

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

Quantification of Cation Sorption to Engineered Barrier Materials Under Extreme Conditions