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Sample records for barrier emplacement experiment

  1. 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

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

    International Nuclear Information System (INIS)

    Bossart, P.; Nussbaum, C.

    2007-01-01

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

  3. Review of potential subsurface permeable barrier emplacement and monitoring technologies

    Energy Technology Data Exchange (ETDEWEB)

    Riggsbee, W.H.; Treat, R.L.; Stansfield, H.J.; Schwarz, R.M. [Ebasco Environmental, Richland, WA (United States); Cantrell, K.J. [Pacific Northwest Lab., Richland, WA (United States); Phillips, S.J. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-02-01

    This report focuses on subsurface permeable barrier technologies potentially applicable to existing waste disposal sites. This report describes candidate subsurface permeable barriers, methods for emplacing these barriers, and methods used to monitor the barrier performance. Two types of subsurface barrier systems are described: those that apply to contamination.in the unsaturated zone, and those that apply to groundwater and to mobile contamination near the groundwater table. These barriers may be emplaced either horizontally or vertically depending on waste and site characteristics. Materials for creating permeable subsurface barriers are emplaced using one of three basic methods: injection, in situ mechanical mixing, or excavation-insertion. Injection is the emplacement of dissolved reagents or colloidal suspensions into the soil at elevated pressures. In situ mechanical mixing is the physical blending of the soil and the barrier material underground. Excavation-insertion is the removal of a soil volume and adding barrier materials to the space created. Major vertical barrier emplacement technologies include trenching-backfilling; slurry trenching; and vertical drilling and injection, including boring (earth augering), cable tool drilling, rotary drilling, sonic drilling, jetting methods, injection-mixing in drilled holes, and deep soil mixing. Major horizontal barrier emplacement technologies include horizontal drilling, microtunneling, compaction boring, horizontal emplacement, longwall mining, hydraulic fracturing, and jetting methods.

  4. Review of potential subsurface permeable barrier emplacement and monitoring technologies

    International Nuclear Information System (INIS)

    Riggsbee, W.H.; Treat, R.L.; Stansfield, H.J.; Schwarz, R.M.; Cantrell, K.J.; Phillips, S.J.

    1994-02-01

    This report focuses on subsurface permeable barrier technologies potentially applicable to existing waste disposal sites. This report describes candidate subsurface permeable barriers, methods for emplacing these barriers, and methods used to monitor the barrier performance. Two types of subsurface barrier systems are described: those that apply to contamination.in the unsaturated zone, and those that apply to groundwater and to mobile contamination near the groundwater table. These barriers may be emplaced either horizontally or vertically depending on waste and site characteristics. Materials for creating permeable subsurface barriers are emplaced using one of three basic methods: injection, in situ mechanical mixing, or excavation-insertion. Injection is the emplacement of dissolved reagents or colloidal suspensions into the soil at elevated pressures. In situ mechanical mixing is the physical blending of the soil and the barrier material underground. Excavation-insertion is the removal of a soil volume and adding barrier materials to the space created. Major vertical barrier emplacement technologies include trenching-backfilling; slurry trenching; and vertical drilling and injection, including boring (earth augering), cable tool drilling, rotary drilling, sonic drilling, jetting methods, injection-mixing in drilled holes, and deep soil mixing. Major horizontal barrier emplacement technologies include horizontal drilling, microtunneling, compaction boring, horizontal emplacement, longwall mining, hydraulic fracturing, and jetting methods

  5. Engineered barrier experiment Mont Terri underground laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J.C. [Empresa Nacional de Residuos Radiactivos, SA (ENRESA), Madrid (Spain); Alonso, E. [Universitat Polytechnica de Catalunya (UPC-CIMNE), Madrid (Spain); Garcia-Sineriz, J.L. [AITEMIN, Madrid (Spain)

    2005-07-01

    The Engineered Barrier (EB) experiment is being carried out at the Mont Terri underground laboratory (Switzerland). The aim of the EB experiment is the demonstration of a new concept for the buffer construction of HLW repositories in horizontal drifts, in competent clay formations. The principle of this new buffer construction method is based on the combined use of a lower bed made of compacted bentonite blocks, and an upper backfill made with a bentonite pellets based material. The emplacement layout proposed in this project represents an important innovation for repositories in horizontal drifts. The fact of filling the upper part of the gap between the canister and the rock with a pellets-based type of material makes the emplacement operation much simpler, eliminating some of the most critical aspects of such operation. The experiment is carried out in a gallery excavated in the shaly facies of the Opalinus clay of Mont Terri. The geometry of the test site is a horseshoe section, 2,55 m high, 3 m wide and 15 m long. A dummy canister of the same dimensions and weight than the reference one was installed on the top of a compacted bentonite blocks bed, and the gap canister-rock was backfilled with compacted bentonite pellets. The experimental area was isolated by a concrete plug. An artificial hydration system was installed to accelerate the hydration process. In order to monitor the evolution of the system and record the values of different parameters, a data acquisition system was installed. (authors)

  6. Implementation of the full-scale emplacement (FE) experiment at the Mont Terri rock laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Müller, H.R.; Garitte, B.; Vogt, T.; and others

    2017-04-15

    Opalinus Clay is currently being assessed as the host rock for a deep geological repository for high-level and low- and intermediate-level radioactive wastes in Switzerland. Within this framework, the 'Full-Scale Emplacement' (FE) experiment was initiated at the Mont Terri rock laboratory close to the small town of St-Ursanne in Switzerland. The FE experiment simulates, as realistically as possible, the construction, waste emplacement, backfilling and early post-closure evolution of a spent fuel/vitrified high-level waste disposal tunnel according to the Swiss repository concept. The main aim of this multiple heater test is the investigation of repository-induced thermo-hydro-mechanical (THM) coupled effects on the host rock at this scale and the validation of existing coupled THM models. For this, several hundred sensors were installed in the rock, the tunnel lining, the bentonite buffer, the heaters and the plug. This paper is structured according to the implementation timeline of the FE experiment. It documents relevant details about the instrumentation, the tunnel construction, the production of the bentonite blocks and the highly compacted 'granulated bentonite mixture' (GBM), the development and construction of the prototype 'backfilling machine' (BFM) and its testing for horizontal GBM emplacement. Finally, the plug construction and the start of all 3 heaters (with a thermal output of 1350 Watt each) in February 2015 are briefly described. In this paper, measurement results representative of the different experimental steps are also presented. Tunnel construction aspects are discussed on the basis of tunnel wall displacements, permeability testing and relative humidity measurements around the tunnel. GBM densities achieved with the BFM in the different off-site mock-up tests and, finally, in the FE tunnel are presented. Finally, in situ thermal conductivity and temperature measurements recorded during the first heating months

  7. Overwash threshold experiment for gravel barriers

    Science.gov (United States)

    Matias, Ana; Williams, Jon; Bradbury, Andrew; Masselink, Gerhard; Ferreira, Óscar

    2010-05-01

    Field measurements of overwash effects, associated physical forcing, and determination of threshold conditions, are much less common for gravel than for sandy barriers (e.g., field measurements by Lorang, 2002; Bradbury et al., 2005; and laboratory studies by Obhrai et al., 2008). In order to define overwash thresholds for gravel there is a need for measurements under a variety of forcing conditions that include waves, tides and surges. Flume experiments allow the manipulation of physical forcing and can make a valuable contribution to improve the understanding and prediction of overwash. To study gravel barrier overwash processes, BARDEX proto-type scale laboratory experiment was undertaken in the Delta flume (Williams et al., 2009). A 4 m high, 50 m wide gravel barrier composed of sediments with D50 = 10 mm was emplaced in the flume and subjected to a range of water levels, wave heights and wave periods. Barrier morphology was surveyed before and after each run. Two situations were simulated: overwashing and overtopping. Following Orford and Carter (1982) terminology, the distinction between overtopping and overwash was based on the type of morphological change over the barrier crest. Overtopping causes vertical accretion at the crest, whereas overwashing promotes the formation of washover deposits landwards from the crest. Ten overwash experiments were conducted (divided in 63 runs), and overtopping was recorded in 22 runs and overwash in 20 runs. In other runs, only the beach face was reworked by waves. In a systematic series of tests water levels were varied between 3.00 m and 3.75 m (in steps of 0.125 m); wave height was varied between 0.8 m and 1.3 m (in steps of 0.05 or 0.1 m); and wave periods of 4.5, 6, 7 and 8 seconds were used. These hydrodynamic conditions were used to compute wave run-up using several well-known formulae (cf., Powell, 1990; Stockdon et al., 2007). Comparison between run-up estimations and the barrier crest elevation prior to wave

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

    International Nuclear Information System (INIS)

    Moody, T.E.; Conca, J.

    1996-09-01

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

  9. Compositional evolution of the emplaced fuel source in the vadose zone field experiment at airbase Vaerlose, Denmark

    DEFF Research Database (Denmark)

    Broholm, Mette Martina; Christophersen, Mette; Maier, U.

    2005-01-01

    A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to test the nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect of biodegrad......A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to test the nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect......, with the exception that the mole fractions of aromatic compounds in the source NAPL decreased faster than fractions of aliphatic compounds of similar volatility. Calculation of activity coefficients (gamma) using the UNIFAC model implied nonideal conditions, with composition-dependent gamma's different from 1...... volatility is both a result of the nonideality of the mixture and a result of partitioning and biodegradation in the pore-water. Vapor concentrations of the compounds in the source were in reasonable agreement with predictions based on the modified Raoult's Law with the UNIFAC predicted gamma's and the NAPL...

  10. Barrier experiment: Shock initiation under complex loading

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-12

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

  11. Barrier bucket experiment at the AGS

    Directory of Open Access Journals (Sweden)

    M. Fujieda

    1999-12-01

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

  12. Compositional evolution of the emplaced fuel source in the vadose zone field experiment at Airbase Verløse, Denmark.

    Science.gov (United States)

    Broholm, Mette M; Christophersen, Mette; Maier, Uli; Stenby, Erling H; Höhener, Patrick; Kjeldsen, Peter

    2005-11-01

    A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to testthe nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect of biodegradation on source evolution. The diffusive loss to the surrounding vadose zone and the atmosphere created temporary gradients in mole fractions of the individual compounds within the source NAPL. The evolution of the source composition corresponded in general with expectations based on Raoult's Law, with the exception thatthe mole fractions of aromatic compounds in the source NAPL decreased faster than fractions of aliphatic compounds of similar volatility. Calculation of activity coefficients (y) using the UNIFAC model implied nonideal conditions, with composition-dependent gammas different from 1. Positive deviations were calculated for the aromatic compounds. The effect of biodegradation on source depletion, evaluated by numerical modeling, was greater for the aromatic as compared to the aliphatic compounds. Hence, the faster depletion of the aromatic relative to aliphatic compounds of similar volatility is both a result of the nonideality of the mixture and a result of partitioning and biodegradation in the pore-water. Vapor concentrations of the compounds in the source were in reasonable agreement with predictions based on the modified Raoult's Law with the UNIFAC predicted gammas and the NAPL composition for the most volatile compounds. For the less volatile compounds, the measured vapor concentrations were lower than predicted with the largest deviations for the least volatile compounds. This field experiment illustrated that nonideal behavior and bioenhanced source depletion need to be considered at multicomponent NAPL spill sites.

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

    Science.gov (United States)

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

    2009-06-01

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

  14. Effects of Fault Displacement on Emplacement Drifts

    International Nuclear Information System (INIS)

    Duan, F.

    2000-01-01

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10 -5 adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M and O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure

  15. Biodegradation of hydrocarbons vapors: Comparison of laboratory studies and field investigations in the vadose zone at the emplaced fuel source experiment, Airbase Værløse, Denmark

    Science.gov (United States)

    Höhener, Patrick; Dakhel, Nathalie; Christophersen, Mette; Broholm, Mette; Kjeldsen, Peter

    2006-12-01

    The natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone can only be predicted when information about microbial biodegradation rates and kinetics are known. This study aimed at determining first-order rate coefficients for the aerobic biodegradation of 13 volatile petroleum hydrocarbons which were artificially emplaced as a liquid mixture during a field experiment in an unsaturated sandy soil. Apparent first-order biodegradation rate coefficients were estimated by comparing the spatial evolution of the resulting vapor plumes to an analytical reactive transport model. Two independent reactive numerical model approaches have been used to simulate the diffusive migration of VOC vapors and to estimate degradation rate coefficients. Supplementary laboratory column and microcosm experiments were performed with the sandy soil at room temperature under aerobic conditions. First-order kinetics adequately matched the lab column profiles for most of the compounds. Consistent compound-specific apparent first-order rate coefficients were obtained by the three models and the lab column experiment, except for benzene. Laboratory microcosm experiments lacked of sensitivity for slowly degrading compounds and underestimated degradation rates by up to a factor of 5. Addition of NH 3 vapor was shown to increase the degradation rates for some VOCs in the laboratory microcosms. All field models suggested a significantly higher degradation rate for benzene than the rates measured in the lab, suggesting that the field microbial community was superior in developing benzene degrading activity.

  16. Biodegradation of hydrocarbons vapors: Comparison of laboratory studies and field investigations in the vadose zone at the emplaced fuel source experiment, Airbase Vaerløse, Denmark.

    Science.gov (United States)

    Höhener, Patrick; Dakhel, Nathalie; Christophersen, Mette; Broholm, Mette; Kjeldsen, Peter

    2006-12-15

    The natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone can only be predicted when information about microbial biodegradation rates and kinetics are known. This study aimed at determining first-order rate coefficients for the aerobic biodegradation of 13 volatile petroleum hydrocarbons which were artificially emplaced as a liquid mixture during a field experiment in an unsaturated sandy soil. Apparent first-order biodegradation rate coefficients were estimated by comparing the spatial evolution of the resulting vapor plumes to an analytical reactive transport model. Two independent reactive numerical model approaches have been used to simulate the diffusive migration of VOC vapors and to estimate degradation rate coefficients. Supplementary laboratory column and microcosm experiments were performed with the sandy soil at room temperature under aerobic conditions. First-order kinetics adequately matched the lab column profiles for most of the compounds. Consistent compound-specific apparent first-order rate coefficients were obtained by the three models and the lab column experiment, except for benzene. Laboratory microcosm experiments lacked of sensitivity for slowly degrading compounds and underestimated degradation rates by up to a factor of 5. Addition of NH3 vapor was shown to increase the degradation rates for some VOCs in the laboratory microcosms. All field models suggested a significantly higher degradation rate for benzene than the rates measured in the lab, suggesting that the field microbial community was superior in developing benzene degrading activity.

  17. Emplacement ventilation system

    International Nuclear Information System (INIS)

    Vance, Robert W.

    2000-01-01

    This analysis updates design concepts for emplacement ventilation based upon the increased air flow required through the drift in the EDA II design (CRWMS M and O 1999a, Table O-6) and by current thermal modeling results compared to the VA design (DOE 1998, Section 4.2.4). It reviews the air pathway in the emplacement drift, describes three exhaust system options, discusses two air control options, and examines concepts for several system physical components including isolation doors, a portable shadow shield, and a partition in an exhaust main. The air path through the emplacement drift, itself, remains the same as described in the VA and EDA II design; that is, exhaust fans located on the surface pull air through an intake shaft into the subsurface repository. The ventilation air is distributed to the east and west mains by the cross-block drifts. From the mains, the air enters the emplacement drifts and flows to a central exhaust raise. The air then travels down an exhaust raise to the exhaust system

  18. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    International Nuclear Information System (INIS)

    Wilson, T.; Novotny, R.

    1999-01-01

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

  19. Solar energy emplacement developer

    Science.gov (United States)

    Mortensen, Michael; Sauls, Bob

    1991-01-01

    A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

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

    African Journals Online (AJOL)

    Experiences of psychosocial and programme-related barriers to recovery in lifestyle interventions for noncommunicable diseases. ... interventions and sustainable secondary prevention of NCDs. Keywords: chronic diseases of lifestyle; intervention evaluation; psychological risk factors; social support; professional conduct ...

  1. Drip Shield Emplacement Gantry Concept

    International Nuclear Information System (INIS)

    Silva, R.A.; Cron, J.

    2000-01-01

    This design analysis has shown that, on a conceptual level, the emplacement of drip shields is feasible with current technology and equipment. A plan for drip shield emplacement was presented using a Drip Shield Transporter, a Drip Shield Emplacement Gantry, a locomotive, and a Drip Shield Gantry Carrier. The use of a Drip Shield Emplacement Gantry as an emplacement concept results in a system that is simple, reliable, and interfaces with the numerous other exising repository systems. Using the Waste Emplacement/Retrieval System design as a basis for the drip shield emplacement concept proved to simplify the system by using existing equipment, such as the gantry carrier, locomotive, Electrical and Control systems, and many other systems, structures, and components. Restricted working envelopes for the Drip Shield Emplacement System require further consideration and must be addressed to show that the emplacement operations can be performed as the repository design evolves. Section 6.1 describes how the Drip Shield Emplacement System may use existing equipment. Depending on the length of time between the conclusion of waste emplacement and the commencement of drip shield emplacement, this equipment could include the locomotives, the gantry carrier, and the electrical, control, and rail systems. If the exisiting equipment is selected for use in the Drip Shield Emplacement System, then the length of time after the final stages of waste emplacement and start of drip shield emplacement may pose a concern for the life cycle of the system (e.g., reliability, maintainability, availability, etc.). Further investigation should be performed to consider the use of existing equipment for drip shield emplacement operations. Further investigation will also be needed regarding the interfaces and heat transfer and thermal effects aspects. The conceptual design also requires further design development. Although the findings of this analysis are accurate for the assumptions made

  2. Magma emplacement in 3D

    Science.gov (United States)

    Gorczyk, W.; Vogt, K.

    2017-12-01

    Magma intrusion is a major material transfer process in Earth's continental crust. Yet, the mechanical behavior of the intruding magma and its host are a matter of debate. In this study, we present a series of numerical thermo-mechanical experiments on mafic magma emplacement in 3D.In our model, we place the magmatic source region (40 km diameter) at the base of the mantle lithosphere and connect it to the crust by a 3 km wide channel, which may have evolved at early stages of magmatism during rapid ascent of hot magmatic fluids/melts. Our results demonstrate continental crustal response due to magma intrusion. We observe change in intrusion geometries between dikes, cone-sheets, sills, plutons, ponds, funnels, finger-shaped and stock-like intrusions as well as injection time. The rheology and temperature of the host-rock are the main controlling factors in the transition between these different modes of intrusion. Viscous deformation in the warm and deep crust favours host rock displacement and magma pools along the crust-mantle boundary forming deep-seated plutons or magma ponds in the lower to middle-crust. Brittle deformation in the cool and shallow crust induces cone-shaped fractures in the host rock and enables emplacement of finger- or stock-like intrusions at shallow or intermediate depth. A combination of viscous and brittle deformation forms funnel-shaped intrusions in the middle-crust. Low-density source magma results in T-shaped intrusions in cross-section with magma sheets at the surface.

  3. 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)

  4. Performance implications of waste package emplacement orientation

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1991-05-01

    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 environment 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

  5. TRANSPORT AND EMPLACEMENT EQUIPMENT DESCRIPTIONS

    International Nuclear Information System (INIS)

    1997-01-01

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) Transport and Emplacement in the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. The Transport and Emplacement equipment described in this document consists of the following: (1) WP Transporter; (2) Reusable Rail Car; (3) Emplacement Gantry; (4) Gantry Carrier; and (5) Transport Locomotive

  6. The first experiments on dielectric barrier discharge under atmospheric pressure

    International Nuclear Information System (INIS)

    Nob, Harada; Yusuke Watabe; Tsuyoshi Watanabe; Ikuo Oshio

    2002-01-01

    In order to obtain uniform and stable discharge plasma in atmospheric pressure, dielectric barrier discharge experiments were carried out. Main purpose is to examine the applicability of dielectric barrier discharge to production processes of semi-conductors. LSIs and flat display panels. In the experiments, at first, quite stable and uniform discharge was obtained at atmospheric pressure. Effects of applied voltage and frequency on plasma uniformity were studied. Improvement of discharge uniformity by introducing gas flow of helium or nitrogen between the discharge gap was observed. Finally, surface cleaning effect of the present plasma was confirmed by observing contact angle of liquid droplet. At least for cleaning process, possibility of application as process plasma was suggested

  7. Construction, emplacement, and retrievability (preclosure)

    International Nuclear Information System (INIS)

    McClain, W.

    1985-01-01

    Each of the three preclosure subgroups of the Construction, Emplacement, and Retrievability Working Group adopted a six-step approach to identify and assess current needs in geotechnical modeling and characterization. This approach may be summarized as follows: identify phenomena related to emplacement of high-level nuclear wastes, identify types of models which are required to calculate the phenomena, establish the input data needs for the models, assess the current availability of the models, assess the current status of documentation, verification, and validation of the models, and determine the adequacy of instrumentation and measurement techniques to (a) validate the models, where necessary, and (b) obtain input data for design. Systematic application of these six steps leads to the establishment of the research requirements for geotechnical modeling and characterization. A summary of modeling techniques which apply to the three subsequent sections on construction, emplacement, and retrievability is presented. Research needs, which apply to all preclosure activities, are summarized

  8. Elements of transport and emplacement system

    International Nuclear Information System (INIS)

    1981-02-01

    This report, undertaken to review proposals for transport, handling and emplacement of high-level radioactive wastes in an underground repository, appropriate to the U.K. context, falls under the headings: basic design concepts; waste block size and configuration; self-shielded or partially shielded blocks; concept of emplacement in long boreholes; concept of emplacement in short boreholes; concept of emplacement in tunnels; methods of emplacement; stages of disposal; repository access by adit, incline or shaft; handling techniques within repository; conventional and radiological safety; costs; areas for further research and development. (U.K.)

  9. Experiments to determine the migration potential for water and contaminants in shallow land-burial facilities: design, emplacement, and preliminary results

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Abeele, W.V.; Burton, B.W.

    1982-01-01

    Although there have been many laboratory studies on water movement and contaminant transport, there is a need for more large scale field experiments. Large scale field experiments are necessary to (1) measure hydraulic conductivities on a scale typical of actual shallow land burial facilities and hazardous waste disposal facilities, (2) allow comparisons to be made between full scale and laboratory measurements, (3) verify the applicability of calculational methods for determining unsaturated hydraulic conductivities from water retention curves, and (4) for model validation. Experiments that will provide the information to do this are described in this paper. The results of these experiments will have applications for both the shallow land burial of low level radioactive wastes and the disposal of hazardous chemical wastes. These experiments will provide results that can be used in model verification for system performance. This type of data on experiments done at this scale has not been available, and are necessary for validating unsaturated transport models and other models used to predict long term system performance. Even though these experiments are done on crushed Bandelier Tuff, most models use physical properties of the backfill material such as density, porosity, and water retention curves. For this reason, once the models are validated in these experiments, they can be applied with confidence to other materials as long as the material properties are well characterized. In addition, from known water movement rates, calculable from the results of these experiments, requirements for other parts of the system such as liners, water diversion systems, and system cap requirements can be determined. Lastly, the results of these experiments and their use in model verification will provide a sound scientific basis on which to base decisions on system requirements and system design

  10. Lessons Learned from Missing Flooding Barriers Operating Experience

    International Nuclear Information System (INIS)

    Simic, Z.; Veira, M. P.

    2016-01-01

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

  11. Permeability of granular beds emplaced in vertical drill holes

    International Nuclear Information System (INIS)

    Griffiths, S.K.; Morrison, F.A. Jr.

    1979-01-01

    To determine the permeabilities of granular materials emplaced in vertical drill holes used for underground nuclear tests, an experiment at the USDOE Nevada Test Site (NTS) was conducted. As the hole is being filled, falling material increases pressure above and within the granular beds beneath. When the filling operation starts or stops, a transient pressure response occurs within the beds; measurements of this response in beds of various compositions were made. The permeabilities after emplacement were found by matching analytical predictions of the response to these data. This information is useful in assuring the containment of nuclear tests conducted in such drill holes

  12. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report presents conceptual design information for a system to handle and emplace packages containing radioactive waste, in boreholes 16,400 ft deep or possibly deeper. Its intended use is for a design selection study that compares the costs and risks associated with two emplacement methods: drill-string and wireline emplacement. The deep borehole disposal (DBD) concept calls for siting a borehole (or array of boreholes) that penetrate crystalline basement rock to a depth below surface of about 16,400 ft (5 km). Waste packages would be emplaced in the lower 6,560 ft (2 km) of the borehole, with sealing of appropriate portions of the upper 9,840 ft (3 km). A deep borehole field test (DBFT) is planned to test and refine the DBD concept. The DBFT is a scientific and engineering experiment, conducted at full-scale, in-situ, without radioactive waste. Waste handling operations are conceptualized to begin with the onsite receipt of a purpose-built Type B shipping cask, that contains a waste package. Emplacement operations begin when the cask is upended over the borehole, locked to a receiving flange or collar. The scope of emplacement includes activities to lower waste packages to total depth, and to retrieve them back to the surface when necessary for any reason. This report describes three concepts for the handling and emplacement of the waste packages: 1) a concept proposed by Woodward-Clyde Consultants in 1983; 2) an updated version of the 1983 concept developed for the DBFT; and 3) a new concept in which individual waste packages would be lowered to depth using a wireline. The systems described here could be adapted to different waste forms, but for design of waste packaging, handling, and emplacement systems the reference waste forms are DOE-owned high- level waste including Cs/Sr capsules and bulk granular HLW from fuel processing. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design July 23, 2015 iv ACKNOWLEDGEMENTS This report has

  13. Waste Emplacement/Retrieval System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-25

    The Waste Emplacement/Retrieval System transports Waste Packages (WPs) from the Waste Handling Building (WHB) to the subsurface area of emplacement, and emplaces the WPs once there. The Waste Emplacement/Retrieval System also, if necessary, removes some or all of the WPs from the underground and transports them to the surface. Lastly, the system is designed to remediate abnormal events involving the portions of the system supporting emplacement or retrieval. During emplacement operations, the system operates on the surface between the WHB and North Portal, and in the subsurface in the North Ramp, access mains, and emplacement drifts. During retrieval or abnormal conditions, the operations areas may also extend to a surface retrieval storage site and South Portal on the surface, and the South Ramp in the subsurface. A typical transport and emplacement operation involves the following sequence of events. A WP is loaded into a WP transporter at the WHB, and coupled to a pair of transport locomotives. The locomotives transport the WP from the WHB, down the North Ramp, and to the entrance of an emplacement drift. Once docked at the entrance of the emplacement drift, the WP is moved outside of the WP transporter, and engaged by a WP emplacement gantry. The WP emplacement gantry lifts the WP, and transports it to its emplacement location, where the WP is then lowered to its final resting position. The WP emplacement gantry remains in the drift while the WP transporter is returned to the WHB by the locomotives. When the transporter reaches the WHB, the sequence of operations is repeated. Retrieval of all the WPs, or a large group of WPs, under normal conditions is achieved by reversing the emplacement operations. Retrieval of a small set of WPs, under normal or abnormal conditions, is known as recovery. Recovery performed under abnormal conditions will involve a suite of specialized equipment designed to perform a variety of tasks to enable the recovery process. Recovery

  14. Intensity Improvement For AD Experiments Using Barrier Bucket Cooling

    CERN Document Server

    Bojtár, L

    2009-01-01

    We propose to cool the antiproton beam confined into a 300 ns or shorter barrier bucket. The longitudinal emittance obtained this way is much smaller than it is possible with coasting beam cooling. This allows beam bunching already in the AD ring with 202.56 MHz, the frequency of the ASACUSA RFQD. The proposed scheme requires the installation of two 202.56 MHz cavities and a barrier bucket cavity into the ring. With this modest investment ASACUSA gains a factor 2-3 in intensity. A proof of principle test has been done during 3 MD sessions recently. The beam emittances in all planes were measured after the beam was cooled in the barrier bucket and were found sufficiently low.

  15. Communication Barrier during Clinical Placement: Challenges and Experiences of International Nursing students

    OpenAIRE

    Awe, Omobolape

    2014-01-01

    ABSTRACT Effective communication in a clinical environment is vital. It plays an important role in patient care, just as language proficiency has been noted to be related to satisfactory learning experiences. This study aimed to understand the experiences of the students in respect to communication barriers during clinical practice and to answer three main re-search questions; 1: Do international student experience communication barrier during clinical placement? 2: What kind of language b...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-03-01

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

  17. Drift emplaced waste package thermal response

    International Nuclear Information System (INIS)

    Ruffner, D.J.; Johnson, G.L.; Platt, E.A.; Blink, J.A.; Doering, T.W.

    1993-01-01

    Thermal calculations of the effects of radioactive waste decay heat on the I repository at Yucca Mountain, Nevada have been conducted by the Yucca Mountain Site Characterization Project (YMP) at Lawrence Livermore National Laboratory (LLNL) in conjunction with the B ampersand W Fuel Company. For a number of waste package spacings, these 3D transient calculations use the TOPAZ3D code to predict drift wall temperatures to 10,000 years following emplacement. Systematic tcniperature variation occurs as a function of fuel age at emplacement and Areal Mass Loading (AML) during the first few centuries after emplacement. After about 1000 years, emplacement age is not a strong driver on rock temperature; AML has a larger impact. High AMLs occur when large waste packages are emplaced end-tocnd in drifts. Drift emplacement of equivalent packages results in lower rock teniperatures than borehole emplacement. For an emplacement scheme with 50% of the drift length occupied by packages, an AML of 138 MTU/acre is about three times higher than the Site Characterization Plan-Conceptual Design (SCP-CD) value. With this higher AML (requiring only 1/3 of the SCP-CD repository footprint), peak drift wall temperatures do not exceed 160*C, but rock temperatures excetd the boiling point of water for about 3000 years. These TOPAZ3D results Iiive been compared with reasonable agreement with two other computer codes

  18. Transpressional granite-emplacement model: Structural and ...

    Indian Academy of Sciences (India)

    the complete emplacement and deformation of the pluton during the Pan-African D2 and D3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi. Tchakam et al. ... emplacement and deformation age of the granitic pluton in a dextral ENE–WSW shear movement. 1.

  19. Waste Emplacement/Retrieval System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-12

    The Waste Emplacement/Retrieval System transports Waste Packages (WPs) from the Waste Handling Building (WHB) to the subsurface area of emplacement, and emplaces the WPs once there. The system also, if necessary, removes some or all of the WPs from the underground and transports them to the surface. Lastly, the system is designed to remediate abnormal events involving the portions of the system supporting emplacement or retrieval. During emplacement operations, the system operates on the surface between the WHB and North Portal, and in the subsurface in the North Ramp, access mains, and emplacement drifts. During retrieval or abnormal conditions, the operations areas may also extend to a surface retrieval storage site and South Portal on the surface, and the South Ramp in the subsurface. A typical transport and emplacement operation involves the following sequence of events. A WP is loaded into a WP transporter at the WHB, and coupled to a pair of transport locomotives. The locomotives transport the WP from the WHB, down the North Ramp, and to the entrance of an emplacement drift. Once docked at the entrance of the emplacment drift, the WP is moved outside of the WP transporter, and engaged by a WP emplacement gantry. The gantry lifts the WP, and transports it to its emplacement location, where the WP is then lowered to its final resting position. The gantry remains in the drift while the WP transporter is returned to the WHB by the locomotives. When the transporter reaches the WHB, the sequence of operations is repeated. Retrieval of all the WPs, or a large group of WPs, under normal conditions is achieved by reversing the emplacement operations. Retrieval of a small set of WPs, under normal or abnormal conditions, is known as recovery. Recovery performed under abnormal conditions will involve a suite of specialized equipment designed to perform a variety of tasks to enable the recovery process. Recovery after abnormal events may require clearing of equipment

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

    Directory of Open Access Journals (Sweden)

    Ahac Saša

    2014-07-01

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

  1. Waste package emplacement borehole option study

    International Nuclear Information System (INIS)

    Streeter, W.S.

    1992-03-01

    This study evaluates the cost and thermal effects of various waste package emplacement configurations that differ in emplacement orientation, number of containers per borehole, and standoff distance at the potential Yucca Mountain nuclear waste repository. In this study, eight additional alternatives to the vertical and horizontal orientation options presented in the Site Characterization Plan Conceptual Design Report are considered. Typical panel layout configurations based on thermal analysis of the waste and cost estimates for design and construction, operations, and closure and decommissioning were made for each emplacement option. For the thermal analysis average waste 10 years out of reactor and the SIM code were used to determine whether the various configurations temperatures would exceed the design criteria for temperature. This study does not make a recommendation for emplacement configuration, but does provide information for comparison of alternatives

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  3. 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

  4. Mechanisms Of Saucer-Shaped Sill Emplacement: Insight From Experimental Modeling

    Science.gov (United States)

    Galland, O.; Planke, S.; Malthe-Sørenssen, A.; Polteau, S.; Svensen, H.; Podladchikov, Y. Y.

    2006-12-01

    It has been recently demonstrated that magma intrusions in sedimentary basins had a strong impact on petroleum systems. Most of these intrusions are sills, and especially saucer-shaped sills. These features can be observed in many sedimentary basins (i.e. the Karoo basin, South Africa; the Norwegian and North Sea; the Tunguska basin, Siberia; the Neuquén basin in Argentina). The occurrence of such features in so various settings suggests that their emplacement results from fundamental processes. However, the mechanisms that govern their formation remain poorly constrained. Experiments were conducted to simulate the emplacement of saucer-shaped magma intrusions in sedimentary basins. The model rock and magma were fine-grained silica flour and molten vegetable oil, respectively. This modeling technique allows simultaneous simulation of magma emplacement and brittle deformation at a basin scale. For our purpose, we performed our experiments without external deformation. During the experiments, the oil was injected horizontally at constant flow rate within the silica flour. Then the oil initially emplaced in a sill, whereas the surface of the model inflated into a smooth dome. Subsequently, the oil propagated upwards along inclined sheets, finally reaching the surface at the edge of the dome. The resulting geometries of the intrusions were saucer-shaped sills. Then the oil solidified, and the model was cut in serial cross-sections through which the structures of the intrusive body and of the overburden can be observed. In order to constraint the processes governing the emplacement of such features, we performed a parametric study based on a set of experiments in which we systematically varied parameters such as the depth of emplacement and the injection flow rate of the oil. Our results showed that saucer diameters are larger at deeper level of emplacement. Opposite trend was obtained with varying injection flow rates. Based on our results, we conducted a detailed

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

    Science.gov (United States)

    Swenne, Christine Leo; Skytt, Bernice

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    J. Joey Blackburn

    2014-10-01

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

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

    Science.gov (United States)

    Brew, Angela; Mantai, Lilia

    2017-01-01

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

  8. Longevity of Emplacement Drift Ground Support Materials

    Energy Technology Data Exchange (ETDEWEB)

    Tang, David H.

    2001-05-30

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M&O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M&O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M&O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4) Evaluate factors

  9. Unmanned Aerial Vehicle for Flow Control Experiments with Dielectric Barrier Discharge Plasma Actuators

    OpenAIRE

    Friedrichs, Wilm

    2014-01-01

    Dielectric Barrier Discharge (DBD) plasma actuators are a relatively novel type of actuators for active flow control. They offer several benefits, such as fast reaction times due to the absence of mechanical parts. On the other hand there are several difficulties which must be overcome before they reach a stage of maturity suitable for application on aircraft. In the present study the design, construction and commissioning of an Unmanned Aerial Vehicle (UAV) for flow control experiments w...

  10. Longevity of Emplacement Drift Ground Support Materials

    International Nuclear Information System (INIS)

    Tang, D.

    2000-01-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M and O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used

  11. Radionuclide transport modeling of diffusion cell experiments specific to a backfill barrier in a salt repository

    International Nuclear Information System (INIS)

    Anderson, H.M.; Pietz, J.M.; Smith, D.M.

    1984-01-01

    Experimental radionuclide migration diffusion cell data have been collected as part of the WIPP Waste Package Performance Program. This data was collected under conditions approximating geologic isolation of a backfill barrier in a salt repository. The experiments are designed to aid in the evaluation of engineered backfill barriers. This paper describes a radionuclide transport model designed to aid interpreting experimental diffusion cell migration data and eventually to simulate the long-term effectiveness of the backfill barrier in a salt repository. The model is designed to test a variety of expressions representative of potential mechanisms for retardation within the backfill for the best-fit with experimental data. From the comparison, the aim is to select the appropriate mechanism from the host of potential mechanisms for retardation. The model employs a novel integral equation approach to the solution of the transport equation with nonlinear retardation terms. The solution technique used in this model is a semi-analytical, iterative method for the general nonlinear problem. It is felt the technique offers improved computational efficiency over comparable finite difference methods. Comparisons between experimental migration diffusion cell data and the model predictions are presented in this paper. Tentative conclusions concerning the importance of the retardation mechanism to radionuclide transport in the backfill barrier will be drawn. 8 references, 7 figures

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  14. The roles, barriers and experiences of rehabilitation therapists in disaster relief: post-earthquake Haiti 2010.

    Science.gov (United States)

    Klappa, Susan; Audette, Jennifer; Do, Sandy

    2014-01-01

    This article describes the roles and experiences of rehabilitation therapists involved in disaster relief work (DRW) in Haiti after the 2010 earthquake. The results of a pilot study and phenomenological study are presented. A phenomenological study of rehabilitation providers' experiences in post-disaster relief care is presented along with preliminary pilot study results. The phenomenological study explored the experiences of therapists from a lived experience perspective through the roles they played in DRW. Participants provided disaster relief through direct patient care, adaptive equipment sourcing and allocation, education and training, community outreach and logistic or administrative duties. Barriers and challenges included: (1) emotions: ups and downs; (2) challenges: working at the edge of practice; (3) education: key to success and sustainability; (4) lessons learned: social responsibility is why we go; and (5) difficulty coming home: no one understands. Therapists play a key role in disaster relief situations. Data presented should encourage organizations to include therapists from early planning to implementation of relief services. Further studies are needed to evaluate the impact of rehabilitation interventions in disaster settings. Understanding the roles and experiences of therapists in disaster relief setting is important Certain barriers to providing care in post-disaster settings exist Those participating in disaster response should be well prepared and aware of that they might be asked to do.

  15. Emplacement and retrieval equipment design considerations for a repository in salt

    International Nuclear Information System (INIS)

    Nair, B.R.; Bahorich, R.J.

    1987-01-01

    The current design concept for the disposal of nuclear high level waste packages in a repository in salt is based on the emplacement of individual packages in vertical boreholes in the underground mine floor. A key requirement is that the waste packages be capable of being retrieved during the last 26 years of the 76-year repository operating period. The unique design considerations relating to the retrieval of waste packages emplaced in bedded salt are presented in this paper. The information is based on the experience developed during the design of vertical emplacement and retrieval equipment in support of the Sandia Defense High Level Waste experiments at the Waste Isolation Pilot Plant. Also included are the impact of retrievability on the design of the equipment, the special salt cutting technology that was developed for this application, and a description of the equipment

  16. EMPLACEMENT GANTRY ITS STANDARDS IDENTIFICATION STUDY

    International Nuclear Information System (INIS)

    Voegele, M.

    2005-01-01

    To date, the project has established ITS performance requirements for SSCs based on identification and categorization of event sequences that may result in a radiological release. These performance requirements are defined within the NSDB. Further, SSCs credited with performing safe functions are classified as ITS. In turn, perform confirmation for these SSCs is sought through the use of consensus code and standards. The purpose of this study is to identify applicable codes and standards for the WP Emplacement Gantry ITS SSCs. Further, this study will form the basis for selection and the extent of applicability of each code and standard. This study is based on the design development completed for LA only. Accordingly, identification of ITS SSCs beyond those defined within the NSDB are based on designs that may be subject to further development during detail design. Furthermore, several design alternatives may still be under consideration to satisfy certain safety functions, and that final selection will not be determined until further design development has occurred. Therefore, for completeness, throughout this study alternative designs currently under considered will be discussed. Further, the results of this study will be subject to evaluation as part of a follow-on GAP analysis study. Based on the results of this study the GAP analysis will evaluate each code and standard to ensure each ITS performance requirement is fully satisfied. When a performance requirement is not fully satisfied a ''gap'' is highlighted. Thereafter, the study will identify supplemental requirements to augment the code or standard to meet performance requirements. Further, the GAP analysis will identify non-standard areas of the design that will be subject to a Development Plan. Non-standard components and non-standard design configurations are defined as areas of the design that do not follow standard industry practices or codes and standards. Whereby, performance confirmation cannot be

  17. EMPLACEMENT DRIFT ISOLATION DOOR CONTROL SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    N.T. Raczka

    1998-09-17

    The purpose of this analysis is to review and refine key design concepts related to the control system presently under consideration for remotely operating the emplacement drift isolation doors at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis will discuss the key design concepts of the control system that may be utilized for remotely monitoring, opening, and closing the emplacement drift isolation doors. The scope and primary objectives of this analysis are to: (1) Discuss the purpose and function of the isolation doors (Presented in Section 7.1). (2) Review the construction of the isolation door and other physical characteristics of the doors that the control system will interface with (Presented in Section 7.2). (3) Discuss monitoring and controlling the operation of the isolation doors with a digital control system (either a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS)) (Presented in Section 7.3). (4) Discuss how all isolation doors can be monitored and controlled from a subsurface central control center (Presented in Section 7.4). This analysis will focus on the development of input/output (I/O) counts including the types of I/O, redundancy and fault tolerance considerations, and processor requirements for the isolation door control system. Attention will be placed on operability, maintainability, and reliability issues for the system operating in the subsurface environment with exposure to high temperatures and radiation.

  18. EMPLACEMENT DRIFT ISOLATION DOOR CONTROL SYSTEM

    International Nuclear Information System (INIS)

    N.T. Raczka

    1998-01-01

    The purpose of this analysis is to review and refine key design concepts related to the control system presently under consideration for remotely operating the emplacement drift isolation doors at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis will discuss the key design concepts of the control system that may be utilized for remotely monitoring, opening, and closing the emplacement drift isolation doors. The scope and primary objectives of this analysis are to: (1) Discuss the purpose and function of the isolation doors (Presented in Section 7.1). (2) Review the construction of the isolation door and other physical characteristics of the doors that the control system will interface with (Presented in Section 7.2). (3) Discuss monitoring and controlling the operation of the isolation doors with a digital control system (either a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS)) (Presented in Section 7.3). (4) Discuss how all isolation doors can be monitored and controlled from a subsurface central control center (Presented in Section 7.4). This analysis will focus on the development of input/output (I/O) counts including the types of I/O, redundancy and fault tolerance considerations, and processor requirements for the isolation door control system. Attention will be placed on operability, maintainability, and reliability issues for the system operating in the subsurface environment with exposure to high temperatures and radiation

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Matthew J Gibson

    2016-07-01

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

  1. Deep Borehole Emplacement Mode Hazard Analysis Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Sevougian, S. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-07

    This letter report outlines a methodology and provides resource information for the Deep Borehole Emplacement Mode Hazard Analysis (DBEMHA). The main purpose is identify the accident hazards and accident event sequences associated with the two emplacement mode options (wireline or drillstring), to outline a methodology for computing accident probabilities and frequencies, and to point to available databases on the nature and frequency of accidents typically associated with standard borehole drilling and nuclear handling operations. Risk mitigation and prevention measures, which have been incorporated into the two emplacement designs (see Cochran and Hardin 2015), are also discussed. A key intent of this report is to provide background information to brief subject matter experts involved in the Emplacement Mode Design Study. [Note: Revision 0 of this report is concentrated more on the wireline emplacement mode. It is expected that Revision 1 will contain further development of the preliminary fault and event trees for the drill string emplacement mode.

  2. A survey of homework use, experience of barriers to homework, and attitudes about the barriers to homework among couples and family therapists.

    Science.gov (United States)

    Dattilio, Frank M; Kazantzis, Nikolaos; Shinkfield, Gregg; Carr, Amanda G

    2011-04-01

    Homework is a therapeutic process that has strong theoretical and empirical basis, but existing research has focused on "compliance" rather than considering the broader and more clinically meaningful construct of "engagement." Absent in the literature is empirical study of the barriers to engagement or study of homework use among couple and family therapists (CFTs). The current study investigates the frequency and type of homework, as well as the influence of homework compliance, quality of compliance, and experience of barriers to compliance on CFTs' attitudes and beliefs toward barriers to homework completion for couples and families. Results indicated CFTs (N=226 AAMFT Clinical members) use homework more often with couples than with families, and CFTs report greater homework compliance and quality of compliance for couples when compared to families. A path analysis examining compliance, quality of compliance, and barriers to compliance as predictors of attitudes/beliefs toward barriers revealed no significant findings. A discussion presents implications for future research and practice for homework in couple and family therapy. © 2011 American Association for Marriage and Family Therapy.

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

    Science.gov (United States)

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

    2014-06-01

    To assess Malaysian government dentists' experience, willingness and barriers in providing domiciliary care for elderly people. A descriptive cross-sectional study was conducted using a self-administered postal questionnaire targeting government dentists working in the Ministry of Health in Peninsular Malaysia. Seven hundred and eleven out of 962 dentists responded with a response rate of 74.0%. Only 36.1% of the dentists had experience in providing domiciliary care for elderly people in the past 2 years with mean number of visit per year of 1. Younger dentists below the age of 30 and those with confidence in providing the service were the most willing to undertake domiciliary care for elderly patients (OR=13.5, poral health service (67.5%), and dentist's unfavourable working condition (64.4%). The majority of Malaysian government dentists had not been involved in providing domiciliary care for elderly patients. Apart from overcoming the barriers, other recommendations include improving undergraduate dental education, education for elderly people and carers, improving dentist's working condition, and introducing domiciliary financial incentive for dentist. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

  4. Reconceptulizing Language Discordance: Meanings and Experiences of Language Barriers in the U.S. and Taiwan.

    Science.gov (United States)

    Hsieh, Elaine

    2018-02-01

    Individuals with language barriers may face challenges unique to a host society. By examining and comparing the sociocultural conditions that can result in providers and patients not sharing the same language in the United States and in Taiwan, I argue that (a) language discordance is a social phenomenon that may entail diverging meanings and experiences in different countries; (b) language-discordant patients may not share similar experiences even if they are in the same country; and (c) disparities in language concordance may be confounded with other disparities and cultural particulars that are unique to a host society. In addition, because English is a dominant language in medicine, language-discordant patients' quality of care in Taiwan can be moderated by their fluency in English.

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

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    2003-01-01

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

  6. Concept of Operations for Waste Transport, Emplacement, and Retrieval

    International Nuclear Information System (INIS)

    Raczka, Norman T.

    2001-01-01

    The preparation of this technical report has two objectives. The first objective is to discuss the base case concepts of waste transport, emplacement, and retrieval operations and evaluate these operations relative to a lower-temperature repository design. Aspects of the operations involved in waste transport, emplacement and retrieval may be affected by the lower-temperature operating schemes. This report evaluates the effects the lower-temperature alternatives may have on the operational concepts involved in emplacing and retrieving waste. The second objective is to provide backup material for the design description, in a traceable and defensible format, for Section 2 of the Waste Emplacement/Retrieval System Description Document

  7. Barriers to breast cancer screening in Australia: experiences of women with physical disabilities.

    Science.gov (United States)

    Peters, Kath; Cotton, Antoinette

    2015-02-01

    To explore the experiences of breast cancer screening for women with physical disabilities. Despite women with disabilities having the same or greater risk of having breast cancer than women without disabilities, they are less likely to uptake breast cancer screening services. Qualitative descriptive study. Twelve women with physical disabilities were recruited for the purpose of this study. Data were collected via semi-structured face to face or telephone interviews. Interviews were transcribed and data were analysed thematically. Overwhelmingly, participants conveyed that their breast screening experiences were negative. The following four themes describe the experiences of breast cancer screening for women with physical disabilities: feeling I'm not in control; being ignored and not listened to; being helpless, alone and afraid and; experiencing pain, torture and humiliation. Women with physical disabilities experience substantial barriers to breast cancer screening. This research highlights that the attitudes and poor communication skills of health professionals served as a deterrent to future screening for participants. By exploring experiences of women with physical disabilities of breast cancer screening, nurses and other health-care professionals can use this to develop and implement optimal approaches, such as collaborative models of care which empower women with disabilities. © 2014 John Wiley & Sons Ltd.

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

    Science.gov (United States)

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

    2017-06-07

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

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

    Directory of Open Access Journals (Sweden)

    Lucy A. Tully

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    de Grood C

    2015-01-01

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

  11. Physicians' experience adopting the electronic transfer of care communication tool: barriers and opportunities.

    Science.gov (United States)

    de Grood, Chloe; Eso, Katherine; Santana, Maria Jose

    2015-01-01

    The purpose of this study was to assess physicians' perceptions on a newly developed electronic transfer of care (e-TOC) communication tool and identify barriers and opportunities toward its adoption. The study was conducted in a tertiary care teaching center as part of a randomized controlled trial assessing the efficacy of an e-TOC communication tool. The e-TOC technology was developed through iterative consultation with stakeholders. This e-TOC summary was populated by acute care physicians (AcPs) and communicated electronically to community care physicians (CcPs). The AcPs consisted of attending physicians, resident trainees, and medical students rotating through the Medical Teaching Unit. The CcPs were health care providers caring for patients discharged from hospital to the community. AcPs and CcPs completed validated surveys assessing their experience with the newly developed e-TOC tool. Free text questions were added to gather general comments from both groups of physicians. Units of analysis were individual physicians. Data from the surveys were analyzed using mixed methods. AcPs completed 138 linked pre- and post-rotation surveys. At post-rotation, each AcP completed an average of six e-TOC summaries, taking an average of 37 minutes per e-TOC summary. Over 100 CcPs assessed the quality of the TOC summaries, with an overall rating of 8.3 (standard deviation: 1.48; on a scale of 1-10). Thematic analyses revealed barriers and opportunities encountered by physicians toward the adoption of the e-TOC tool. While the AcPs highlighted issues with timeliness, usability, and presentation, the CcPs identified barriers accessing the web-based TOC summaries, emphasizing that the summaries were timely and the quality of information supported continuity of care. Despite the barriers identified by both groups of physicians, the e-TOC communication tool was well received. Our experience can serve as a template for other health research teams considering the implementation

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

    Directory of Open Access Journals (Sweden)

    Dawson Anna P

    2012-05-01

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

  13. WP EMPLACEMENT CONTROL AND COMMUNICATION EQUIPMENT DESCRIPTIONS

    International Nuclear Information System (INIS)

    Raczka, N.T.

    1997-01-01

    The objective and scope of this document are to list and briefly describe the major control and communication equipment necessary for waste package emplacement at the proposed nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the required equipment are explained and summarized in the individual subsections of this document. This task was evaluated in accordance with QAP-2-0 and found not to be quality affecting. Therefore, this document was prepared in accordance with NAP-MG-012. The following control and communication equipment are addressed in this document: (1) Programmable Logic Controllers (PLC's); (2) Leaky Feeder Radio Frequency Communication Equipment; (3) Slotted Microwave guide Communication Equipment; (4) Vision Systems; (5) Radio Control Equipment; and (6) Enclosure Cooling Systems

  14. Additive Construction with Mobile Emplacement (ACME)

    Science.gov (United States)

    Vickers, John

    2015-01-01

    The Additive Construction with Mobile Emplacement (ACME) project is developing technology to build structures on planetary surfaces using in-situ resources. The project focuses on the construction of both 2D (landing pads, roads, and structure foundations) and 3D (habitats, garages, radiation shelters, and other structures) infrastructure needs for planetary surface missions. The ACME project seeks to raise the Technology Readiness Level (TRL) of two components needed for planetary surface habitation and exploration: 3D additive construction (e.g., contour crafting), and excavation and handling technologies (to effectively and continuously produce in-situ feedstock). Additionally, the ACME project supports the research and development of new materials for planetary surface construction, with the goal of reducing the amount of material to be launched from Earth.

  15. Emplacement of sandstone intrusions during contractional tectonics

    Science.gov (United States)

    Palladino, Giuseppe; Grippa, Antonio; Bureau, Denis; Alsop, G. Ian; Hurst, Andrew

    2016-08-01

    Sandstone injections are created by the forceful emplacement of remobilized sand in response to increases in overpressure. However, the contribution provided by horizontal compressive stress to the build-up in overpressure, and the resulting emplacement of sand injection complexes, is still to be substantiated by robust field observations. An opportunity to address this issue occurs in Central California where a large volume of sandstone intrusions record regionally-persistent supra-lithostatic pore-pressure. Detailed fieldwork allows sandstone-filled thrusts to be recognized and, for the first time, permits us to demonstrate that some sandstone intrusions are linked to contractional deformation affecting the western border of the Great Valley Basin. Fluidized sand was extensively injected along thrust surfaces, and also fills local dilatant cavities linked to thrusting. The main aims of this paper are to provide detailed descriptions of the newly recognized syn-tectonic injections, and describe detailed cross-cutting relationships with earlier sandstone injection complexes in the study area. Finally, an evolutionary model consisting of three phases of sand injection is provided. In this model, sand injection is linked to contractional tectonic episodes affecting the western side of the Great Valley Basin during the Early-Middle Cenozoic. This study demonstrates that sand injections, driven by fluid overpressure, may inject along thrusts and folds and thereby overcome stresses associated with regional contractional deformation. It is shown that different generations of sand injection can develop in the same area under the control of different stress regimes, linked to the evolving mountain chain.

  16. Study on a transportation and emplacement system of pre-assembled EBS module for HLW geological disposal

    International Nuclear Information System (INIS)

    Awano, Toshihiko; Kanno, Takeshi; Katsumata, Syunsuke; Kosuge, Kazuhiro

    2009-01-01

    HLW disposal is one of the largest issue to utilize Nuclear power safely. In the past study, the concept, which buffer materials and Overpacked waste were transported into underground respectively, have shown. The concept of pre-assembled engineered barrier has advantage to simplify the logistics and emplacement procedure, however there are difficulties to support heavy weight of pre-assembled package by equipment under the condition of little clearance between tunnel and package. In this study, Combination of air bearing and two degree-of-freedom wheels were suggested for transportation, and air jack was suggested for unloading and emplacement system. Also, whole system for transportation and emplacement procedure was designed, and Scale model test was examined to evaluate the feasibility of these concept and functions. (author)

  17. Disability and the gym: experiences, barriers and facilitators of gym use for individuals with physical disabilities.

    Science.gov (United States)

    Richardson, Emma V; Smith, Brett; Papathomas, Anthony

    2017-09-01

    Individuals with physical disabilities are among the most inactive population in society, arguably due to the lack of suitable environments to exercise. The gym is a space dedicated to improving physical fitness in a controlled environment with specialized equipment and qualified instructors. The feasibility of using this space to promote health to this population, however, is yet to be established. Over an 18-month period, 21 people with physical disabilities were interviewed regarding their experiences in the gym. Data were collected using semi-structured interviews, transcribed verbatim, and subject to thematic analysis. Four broad themes were identified: (1) experiencing enhanced well-ness, (2) perceived conflict between gym values and disability, (3) influence of a previous gym identity, and (4) experiences of psycho-emotional disablism. Participants were perceived to experience a variety of health benefits; however, they also experienced many barriers such as not aligning to the cultural norms of the gym, limited interpretations of health, oppressive messages from the built environment, and negative relational interactions. While there is potential for the gym to be used as a place to promote health, more must be done to foster an inclusive atmosphere in this space. Implications for Research The gym may be a viable place to promote health enhancing behaviors to this population as participants perceived physical, social, and psychological improvements through exercising in this space. Barriers such as not aligning to cultural norms of the gym, psycho-emotional disablism, and a lack of representation in the gym were perceived to hinder exercise participation. Gyms should consider funding instructors to go on courses teaching them how to train an individual with a disability, and also consider employing instructors with a disability to mediate the socio-cultural barriers perceived to exist in the gym. Men and women's past identity as gym users had different

  18. Managing childhood eczema: qualitative study exploring carers' experiences of barriers and facilitators to treatment adherence.

    Science.gov (United States)

    Santer, Miriam; Burgess, Hana; Yardley, Lucy; Ersser, Steven J; Lewis-Jones, Sue; Muller, Ingrid; Hugh, Catherine; Little, Paul

    2013-11-01

    To explore parents and carers' experiences of barriers and facilitators to treatment adherence in childhood eczema Childhood eczema is common and causes significant impact on quality of life for children and their families, particularly due to sleep disturbance and itch. Non-adherence to application of topical treatments is the main cause of treatment failure. Qualitative interview study. Qualitative interviews were carried out with 31 carers from 28 families of children with eczema. Participants were recruited through primary care and included if they had a child aged 5 or less with a diagnosis of eczema. Interviews were carried out between December 2010-May 2011. Data were analysed using a constant comparative approach. Barriers to treatment adherence included carer beliefs around eczema treatment, the time consuming nature of applying topical treatments, and child resistance to treatment. Families employed a range of strategies in an attempt to work around children's resistance to treatment with varying success. Strategies included involving the child in treatment, distracting the child during treatment, or making a game of it, using rewards, applying treatment to a sleeping child or, in a few cases, physically restraining the child. Some carers reduced frequency of applications in an attempt to reduce child resistance. Regular application of topical treatments to children is an onerous task, particularly in families where child resistance develops. Early recognition and discussion of resistance and better awareness of the strategies to overcome this may help carers to respond positively and avoid establishing habitual confrontation. © 2013 Blackwell Publishing Ltd.

  19. Barriers Experie nced by Middle School Students in the P rocess of Learning English

    Directory of Open Access Journals (Sweden)

    Özlem Çelik

    2016-01-01

    Full Text Available English has gained a significant role in technological, business, economic or political areas and has been a part of educational policies in different countries. However, many learners of English have difficulties in learning and using the language effectively due to a number of reasons. Accordingly, a descriptive study was conducted in order to investigate what kind of foreign language (English learning problems the middle school students experience in Turkey. A total of 164 (92 female and 72 male middle school students (5th, 6th, 7th, 8th grade in 4 public schools in Sakarya, Turkey participated in the study. The data were collected through an open-ended question and semi-structured interviews. The collected data were analyzed and coded thematically. The results have indicated that middle school students mostly face linguistic, instructional, affective barriers as well as lack of assistance and useful resource. Considering the findings, some possible reasons and suggestions were also provided to help teachers and learners overcome the relevant barriers in learning English as a foreign language (EFL in Turkey.

  20. Direct burial and vault emplacement data quality comparison at Dotson Ranch, New Mexico

    Science.gov (United States)

    Beaudoin, B. C.; Aderhold, K.; Anderson, K.; Pfeifer, M.; Parker, T.; Miller, P. E.; Slad, G. W.; Reusch, A.

    2013-12-01

    noise levels are similar at all sensors and are likely due to cultural activity and temperature fluctuations. The conclusion from this study is that the shallow vault emplacement method does not provide significant improvement in data quality compared to direct burial emplacement method. Further experiments are underway in a less noisy environment at Poker Flat Research Range in Alaska.

  1. Addressing barriers to health: Experiences of breastfeeding mothers after returning to work.

    Science.gov (United States)

    Valizadeh, Sousan; Hosseinzadeh, Mina; Mohammadi, Eesa; Hassankhani, Hadi; M Fooladi, Marjaneh; Schmied, Virginia

    2017-03-01

    Breastfeeding mothers returning to work often feel exhausted as they must feed on demand and attend to family and employment responsibilities, leading to concerns for their personal health. This study was prompted by a desire to understand and identify barriers to mothers' health. We describe the experiences of 12 Iranian breastfeeding and employed mothers through in-depth and semi-structured interviews and thematic analysis. Two main themes emerged: (i) working and mothering alone and (ii) facing concerns about health. The findings highlight the need for a support system for breastfeeding mothers within the family and in the workplace. Family-friendly policies targeting mothers' and employers' views are needed to support working mothers and promote breastfeeding. © 2017 John Wiley & Sons Australia, Ltd.

  2. Borders as barriers to tourism: tourists experiences at the Beitbridge Border Post (Zimbabwean side

    Directory of Open Access Journals (Sweden)

    Getrude Kwanisai

    2014-01-01

    Full Text Available International borders greatly influence tourism development. In 2012 and 2013, a decline in tourists to Zimbabwe from South Africa was partially attributed to tourist border facilitation issues. It is against this background that this study sought to establish the nature of challenges faced by tourists when using the Beitbridge border post (Zimbabwean side. Questionnaire responses were thematically analysed and the study concluded that border administrative management related issues are a major barrier to tourism. Key among the study's recommendations is that the depressed tourists' border experiences obtaining at Beitbridge border post among other constraints have to be addressed as a matter of urgency. This will enhance Zimbabwe's accessibility, tourist satisfaction and the image of the country as a destination. The paper further identifies several destination managerial implications and future research priorities.

  3. Novel Active Learning Experiences for Students to Identify Barriers to Independent Living for People with Disabilities.

    Science.gov (United States)

    McArthur, Polly; Burch, Lillian; Moore, Katherine; Hodges, Mary Sue

    2016-07-01

    This article describes interactive learning about independent living for people with disabilities and features the partnership of the College of Nursing and a Center for Independent Living (CIL). Using qualitative descriptive approach, students' written reflections were analyzed. Through "Xtreme Challenge," 82 undergraduate nursing students participated in aspects of independent living as well as identifying barriers. Students were engaged and learned to consider the person before the disability. Moreover, students valued the activity leaders' openness, which facilitated understanding the point of view of a person with disability. The value of partnership was evident as it allowed students to participate in active learning, which led to growth in the affective domain. Students became aware of potential education resources through the CIL. This article will guide educators in designing experiences that teach nursing care at the individual, family, and community level for people living with disabilities. © 2015 Association of Rehabilitation Nurses.

  4. Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2010-09-01

    Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an "effective" barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e

  5. Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2010-01-01

    Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an “effective” barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e

  6. Teleoperation of the Small Emplacement Excavator

    International Nuclear Information System (INIS)

    Burks, B.L.; Hannah, J.H.; Killough, S.M.; Thompson, D.H.

    1992-01-01

    A project is under way at the Oak Ridge National Laboratory (ORNL) to convert a military tractor called the Small Emplacement Excavator (SEE) from conventional, manual control to teleoperated control. The SEE is equipped with a backhoe on the back end and multiple blade attachments for the front The SEE is typically used by the US Army for excavation of unexploded ordinance and for battlefield excavation tasks such as entrenchments and foxholes. Because of the risk of personnel injury from explosions during bomb excavation, the US Army is interested in remotely operating the SEE. Excavation of unexploded bombs requires backhoe operations that are very similar to some of the operations envisioned for retrieval of buried radioactive waste at many of the Department of Energy (DOE) sites. Therefore, teleoperation of the SEE is being sponsored jointly by the DOE Environmental Restoration and Waste Management Office of Technology Development, Robotics Technology Development Program, and the Department of Defense (DOD), US Army Program Manager-Ammunition Logistics. After initial development activities at ORNL in 1992, teleoperation of the SEE will be demonstrated at other DOE and DOD sites during FY 1993. The performance of the system will be enhanced through planned follow-on development. The objective of this project is to merge recently developed DOE remote operations technology with proven military heavy equipment in a cost-effective manner. The result will be a remotely operated excavating device that both DOE and DOD can replicate inexpensively and apply widely to hazardous field operations

  7. Barriers to and Facilitators of Help-Seeking Behavior Among Men Who Experience Sexual Violence.

    Science.gov (United States)

    Donne, Martina Delle; DeLuca, Joseph; Pleskach, Pavel; Bromson, Christopher; Mosley, Marcus P; Perez, Edward T; Mathews, Shibin G; Stephenson, Rob; Frye, Victoria

    2018-03-01

    Research on sexual violence and related support services access has mainly focused on female victims; there is still a remarkable lack of research on men who experience sexual violence. Research demonstrates that people who both self-identify as men and are members of sexual-orientation minority populations are at higher risk of sexual violence. They are also less likely to either report or seek support services related to such experiences. The present study is an exploratory one aimed at filling the gap in the literature and better understanding how men, both straight and gay as well as cisgender and transgender, conceptualize, understand, and seek help related to sexual violence. A sample of 32 men was recruited on-line and participated in either a one-on-one in-depth interview ( N = 19) or one of two focus group discussions ( N = 13). All interviews and groups were audiotaped, professionally transcribed and coded using NVivo 9 qualitative software. The present analysis focused on barriers to and facilitators of support service access. Emergent and cross-cutting themes were identified and presented, with an emphasis on understanding what factors may prevent disclosure of a sexual violence experience and facilitate seeking support services and/or professional help. Through this analysis, the research team aims to add knowledge to inform the development of tools to increase service access and receipt, for use by both researchers and service professionals. Although this study contributes to the understanding of the issue of men's experiences of sexual violence, more research with diverse populations is needed.

  8. Reported barriers to evaluation in chronic care: experiences in six European countries.

    Science.gov (United States)

    Knai, Cécile; Nolte, Ellen; Brunn, Matthias; Elissen, Arianne; Conklin, Annalijn; Pedersen, Janice Pedersen; Brereton, Laura; Erler, Antje; Frølich, Anne; Flamm, Maria; Fullerton, Birgitte; Jacobsen, Ramune; Krohn, Robert; Saz-Parkinson, Zuleika; Vrijhoef, Bert; Chevreul, Karine; Durand-Zaleski, Isabelle; Farsi, Fadila; Sarría-Santamera, Antonio; Soennichsen, Andreas

    2013-05-01

    The growing movement of innovative approaches to chronic disease management in Europe has not been matched by a corresponding effort to evaluate them. This paper discusses challenges to evaluation of chronic disease management as reported by experts in six European countries. We conducted 42 semi-structured interviews with key informants from Austria, Denmark, France, Germany, The Netherlands and Spain involved in decision-making and implementation of chronic disease management approaches. Interviews were complemented by a survey on approaches to chronic disease management in each country. Finally two project teams (France and the Netherlands) conducted in-depth case studies on various aspects of chronic care evaluation. We identified three common challenges to evaluation of chronic disease management approaches: (1) a lack of evaluation culture and related shortage of capacity; (2) reluctance of payers or providers to engage in evaluation and (3) practical challenges around data and the heterogeity of IT infrastructure. The ability to evaluate chronic disease management interventions is influenced by contextual and cultural factors. This study contributes to our understanding of some of the most common underlying barriers to chronic care evaluation by highlighting the views and experiences of stakeholders and experts in six European countries. Overcoming the cultural, political and structural barriers to evaluation should be driven by payers and providers, for example by building in incentives such as feedback on performance, aligning financial incentives with programme objectives, collectively participating in designing an appropriate framework for evaluation, and making data use and accessibility consistent with data protection policies. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Extracurricular research activities among senior medical students in Kuwait: experiences, attitudes, and barriers.

    Science.gov (United States)

    Al-Halabi, Becher; Marwan, Yousef; Hasan, Mohammad; Alkhadhari, Sulaiman

    2014-01-01

    Research is the foundation of scientific advancement and improvement in quality of health care, which ensures the good health of the community. The aim of this study is to explore experiences, attitudes, and barriers of medical students in Kuwait University (KU) in regards to extracurricular research. A questionnaire about extracurricular research activities (ie, any research activity that is not part of the required undergraduate curriculum, such as publishing a paper, research elective, etc) was distributed to 175 senior medical students (years 6 and 7). Descriptive and chi-square analyses were used to analyze the responses, considering a P-value of extracurricular research activities. Of the 150 participants (response rate = 85.7%), 26 (17.3%), 68 (45.3%), 52 (34.7%), and 17 (11.3%) had published their required medical school research, presented abstracts in conferences, conducted extracurricular research, and completed a research elective/course, respectively; 99 (66.0%) took part in any of these activities. Participants who read medical journals regularly (81; 54%) reported higher participation in extracurricular research activities than those who did not read journals (P=0.003). Improving the availability of mentors for students' extracurricular research was ranked by the participants as the most important factor to improve their participation in extracurricular research (4.05/5.00). Despite the lack of adequate support, extracurricular research activities among medical students of KU were comparable to students from other countries. Barriers for these activities should be addressed by KU medical educators in order to enhance research activities among the students.

  10. War experiences, general functioning and barriers to care among former child soldiers in Northern Uganda: the WAYS study.

    Science.gov (United States)

    Amone-P'Olak, Kennedy; Jones, Peter; Meiser-Stedman, Richard; Abbott, Rosemary; Ayella-Ataro, Paul Stephen; Amone, Jackson; Ovuga, Emilio

    2014-12-01

    Exposure to war is associated with considerable risks for long-term mental health problems (MHP) and poor functioning. Yet little is known about functioning and mental health service (MHS) use among former child soldiers (FCS). We assessed whether different categories of war experiences predict functioning and perceived need for, sources of and barriers to MHS among FCS. Data were drawn from an on-going War-affected Youths (WAYS) cohort study of FCS in Uganda. Participants completed questionnaires about war experiences, functioning and perceived need for, sources of and barriers to MHS. Regression analyses and parametric tests were used to assess between-group differences. Deaths, material losses, threat to loved ones and sexual abuse significantly predicted poor functioning. FCS who received MHS function better than those who did not. Females reported more emotional and behavioural problems and needed MHS more than males. FCS who function poorly indicated more barriers to MHS than those who function well. Stigma, fear of family break-up and lack of health workers were identified as barriers to MHS. Various war experiences affect functioning differently. A significant need for MHS exists amidst barriers to MHS. Nevertheless, FCS are interested in receiving MHS and believe it would benefit them. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. HRE-Pond Cryogenic Barrier Technology Demonstration: Pre- and Post-Barrier Hydrologic Assessment

    International Nuclear Information System (INIS)

    Moline, G.R.

    1999-01-01

    The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes on the Oak Ridge Reservation (ORR) in east Tennessee. The pond received radioactive wastes from 1957 to 1962, and was subsequently drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by an unnamed stream that contains significant concentrations of radioactive contaminants, primarily 90 Sr. Because of the proximity of the stream to the HRE disposal site and the probable flow of groundwater from the site to the stream, it was hypothesized that the HRE Pond has been a source of contamination to the creek. The HRE-Pond was chosen as the site of a cryogenic barrier demonstration to evaluate this technology as a means for rapid, temporary isolation of contaminants in the type of subsurface environment that exists on the ORR. The cryogenic barrier is created by the circulation of liquid CO 2 through a system of thermoprobes installed in boreholes which are backfilled with sand. The probes cool the subsurface, creating a vertical ice wall by freezing adjacent groundwater, effectively surrounding the pond on four sides. The purpose of this investigation was to evaluate the hydrologic conditions within and around the pond prior to, during, and after the cryogenic barrier emplacement. The objectives were (1) to provide a hydrologic baseline for post-banner performance assessment, (2) to confirm that the pond is hydraulically connected to the surrounding sediments, (3) to determine the likely contaminant exit pathways from the pond, and (4) to measure changes in hydrologic conditions after barrier emplacement in order to assess the barrier performance. Because relatively little information about the subsurface hydrology and the actual configuration of the pond existed, data from multiple sources was required to reconstruct this complex system

  12. HRE-Pond Cryogenic Barrier Technology Demonstration: Pre- and Post-Barrier Hydrologic Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Moline, G.R.

    1999-06-01

    The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes on the Oak Ridge Reservation (ORR) in east Tennessee. The pond received radioactive wastes from 1957 to 1962, and was subsequently drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by an unnamed stream that contains significant concentrations of radioactive contaminants, primarily {sup 90}Sr. Because of the proximity of the stream to the HRE disposal site and the probable flow of groundwater from the site to the stream, it was hypothesized that the HRE Pond has been a source of contamination to the creek. The HRE-Pond was chosen as the site of a cryogenic barrier demonstration to evaluate this technology as a means for rapid, temporary isolation of contaminants in the type of subsurface environment that exists on the ORR. The cryogenic barrier is created by the circulation of liquid CO{sub 2} through a system of thermoprobes installed in boreholes which are backfilled with sand. The probes cool the subsurface, creating a vertical ice wall by freezing adjacent groundwater, effectively surrounding the pond on four sides. The purpose of this investigation was to evaluate the hydrologic conditions within and around the pond prior to, during, and after the cryogenic barrier emplacement. The objectives were (1) to provide a hydrologic baseline for post-banner performance assessment, (2) to confirm that the pond is hydraulically connected to the surrounding sediments, (3) to determine the likely contaminant exit pathways from the pond, and (4) to measure changes in hydrologic conditions after barrier emplacement in order to assess the barrier performance. Because relatively little information about the subsurface hydrology and the actual configuration of the pond existed, data from multiple sources was required to reconstruct this complex system.

  13. Barriers to contraceptive access after health care reform: experiences of young adults in Massachusetts.

    Science.gov (United States)

    Bessett, Danielle; Prager, Joanna; Havard, Julia; Murphy, Danielle J; Agénor, Madina; Foster, Angel M

    2015-01-01

    To explore how Massachusetts' 2006 health insurance reforms affected access to sexual and reproductive health (SRH) services for young adults. We conducted 11 focus group discussions across Massachusetts with 89 women and men aged 18 to 26 in 2009. Most young adults' primary interaction with the health system was for contraceptive and other SRH services, although they knew little about these services. Overall, health insurance literacy was low. Parents were primary decision makers in health insurance choices or assisted their adult children in choosing a plan. Ten percent of our sample was uninsured at the time of the discussion; a lack of knowledge about provisions in Chapter 58 rather than calculated risk analysis characterized periods of uninsurance. The dynamics of being transitionally uninsured, moving between health plans, and moving from a location defined by insurance companies as the coverage area limited consistent access to contraception. Notably, staying on parents' insurance through extended dependency, a provision unique to the post-reform context, had implications for confidentiality and access. Young adults' access to and utilization of contraceptive services in the post-reform period were challenged by unanticipated barriers related to information and privacy. The experience in Massachusetts offers instructive lessons for the implementation of national health care reform. Young adult-targeted efforts should address the challenges of health service utilization unique to this population. Copyright © 2015 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

  14. Information barriers and social stratification in higher education: evidence from a field experiment.

    Science.gov (United States)

    Abbiati, Giovanni; Argentin, Gianluca; Barone, Carlo; Schizzerotto, Antonio

    2017-11-29

    Our contribution assesses the role of information barriers for patterns of participation in Higher Education (HE) and the related social inequalities. For this purpose, we developed a large-scale clustered randomised experiment involving over 9,000 high school seniors from 62 Italian schools. We designed a counseling intervention to correct student misperceptions of the profitability of HE, that is, the costs, economic returns and chances of success of investments in different tertiary programs. We employed a longitudinal survey to test whether treated students' educational trajectories evolved differently relative to a control group. We find that, overall, treated students enrolled less often in less remunerative fields of study in favour of postsecondary vocational programmes. Most importantly, this effect varied substantially by parental social class and level of education. The shift towards vocational programmes was mainly due to the offspring of low-educated parents; in contrast, children of tertiary graduates increased their participation in more rewarding university fields. Similarly, the redistribution from weak fields to vocational programmes mainly involved the children of the petty bourgeoisie and the working class, while upper class students invested in more rewarding university fields. We argue that the status-maintenance model proposed by Breen and Goldthorpe can explain these socially differentiated treatment effects. Overall, our results challenge the claim that student misperceptions contribute to horizontal inequalities in access to HE. © London School of Economics and Political Science 2017.

  15. Barriers and facilitators for vaginal breech births in Australia: Clinician's experiences.

    Science.gov (United States)

    Catling, C; Petrovska, K; Watts, N; Bisits, A; Homer, C S E

    2016-04-01

    Since the Term Breech Trial in 2000, few Australian clinicians have been able to maintain their skills to facilitate vaginal breech births. The overwhelming majority of women with a breech presentation have been given one birth option, that is, caesarean section. The aim of this study was to explore clinician's experiences of caring for women when facilitating a vaginal breech birth. A descriptive exploratory design was undertaken. Nine clinicians (obstetricians and midwives) from two tertiary hospitals in Australia who regularly facilitate vaginal breech birth were interviewed. The interviews were analysed thematically. Participants were five obstetricians and four midwives. There were two overarching themes that arose from the data: Facilitation of and Barriers to vaginal breech birth. A number of sub-themes are described in the paper. In order to facilitate vaginal breech birth and ensure it is given as an option to women, it is necessary to educate, upskill and support colleagues to increase their confidence and abilities, carefully counsel and select suitable women, and approach the option in a calm, collaborative way. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  16. Field test demonstration of emplacement feasibility of precompacted clay buffer materials in a granitic medium

    International Nuclear Information System (INIS)

    Jorda, M.; Lajudie, A.; Gatabin, C.; Atabek, R.

    1992-01-01

    Field test demonstration of emplacement feasibility of precompacted clay buffer materials in a granitic medium has been successfully carried out in February 1990 at the mining centre of FANAY. SILORD site was selected allowing the drilling through the 'Raise Boring' technique of pits of 30 m depth minimum between two pre-existent galleries. Two pits of 37 m depth were drilled and characterized in detail: mean diameter and vertical deviation measurements, valuation of the surface condition (rugosity) and cracking. The pit which was the most regular was selected for the feasibility test it-self. In parallel, manufacturing and handling techniques for the engineered barrier were improved. The bricks were made from a powdered mixture of clay and 10% sand and formed the barrier which was installed in the pit using iron baskets. The technique used was compacting by uniaxial pressing at 64 MPa. Twenty eight baskets containing the engineered barrier were fabricated at LIBOS (refractory manufactory of CTE Group) and taken to FANAY-SILORD. A maximal diameter of 96.03 cm was determined for the basket passing through (basket height = 1.335 m) and verified by the lowering of basket gauges in the pit. The baskets were stacked up in the pit, without any difficulty, with a mean radial gap of 1.6 cm (for a pit mean diameter of 99.3 cm). Three simulated COGEMA waste containers were then satisfactorily installed. The real volume to be sealed, including residual voids, was estimated at 21.47 m 3 . The engineered barrier weight after emplacement came to 36280 kg leading to a dry density in service, i.e. after the engineered barrier swelling, of 1.69. 30 figs

  17. LEARNING CURVES OF LAPAROSCOPY – BARRIERS TO ADOPTION: A MNJIO EXPERIENCE!

    Directory of Open Access Journals (Sweden)

    Ramesh Maturi

    2016-06-01

    Full Text Available BACKGROUND Laparoscopy has been a new entry in the field of surgery with an active history of around just two decades. Today, it is in a position to challenge the conventional surgery which is in use since ages. It is making rapid inroads into various disciplines of surgery. Rapid improvements in optics, along with improvements in energy devices and mechanical stapling devices gave a fillip to acceptance of laparoscopy by the majority of surgeons. Also accumulating data and evidence has started influencing the sceptical, mobilising them to jump into the bandwagon. Barriers to adoption of new techniques, resistance to learning are common to human nature and it is necessary to have a systematic overview of the issues that might crop, so as to be prepared to overcome the problems of accepting laparoscopy into established centres of surgery. AIMS This publication is a reflection of our experience, our trials and tribulations in taking forward the laparoscopy program at our institution. This publication will give an overview of the steps involved in initiation of laparoscopy and aspires to be a source of answers, for day-to-day issues that crop during the process of learning laparoscopy. METHODS AND MATERIALS Just the way, executing laparoscopic surgery is a team effort, incorporating laparoscopy program in an institution is also a team effort where the members of team extend beyond the operating room. Involvement and co-operation of individuals across departments is a must along with benevolent seniors and a proactive administration. So we collated data by interviewing all the stakeholders of laparoscopy program, analysed observations of the faculty from the operating room and reviewed literature on the world wide web. Opinions of the administrators about their perceptions and the issues faced by the junior staff of the department were taken into consideration. Patients were interviewed before and after laparoscopic surgery. CONCLUSIONS Success at

  18. CO2 Dissociation using the Versatile Atmospheric Dielectric Barrier Discharge Experiment (VADER)

    Science.gov (United States)

    Lindon, Michael Allen

    As of 2013, the Carbon Dioxide Information Analysis Center (CDIAC) estimates that the world emits approximately 36 trillion metric tons of Carbon Dioxide (CO2) into the atmosphere every year. These large emissions have been correlated to global warming trends that have many consequences across the globe, including glacial retraction, ocean acidification and increased severity of weather events. With green technologies still in the infancy stage, it can be expected that CO2 emissions will stay this way for along time to come. Approximately 41% of the emissions are due to electricity production, which pump out condensed forms of CO2. This danger to our world is why research towards new and innovative ways of controlling CO2 emissions from these large sources is necessary. As of now, research is focused on two primary methods of CO2 reduction from condensed CO2 emission sources (like fossil fuel power plants): Carbon Capture and Sequestration (CCS) and Carbon Capture and Utilization (CCU). CCS is the process of collecting CO2 using absorbers or chemicals, extracting the gas from those absorbers and finally pumping the gas into reservoirs. CCU on the other hand, is the process of reacting CO2 to form value added chemicals, which can then be recycled or stored chemically. A Dielectric Barrier discharge (DBD) is a pulsed, low temperature, non-thermal, atmospheric pressure plasma which creates high energy electrons suitable for dissociating CO2 into its components (CO and O) as one step in the CCU process. Here I discuss the viability of using a DBD for CO2 dissociation on an industrial scale as well as the fundamental physics and chemistry of a DBD for CO2 dissociation. This work involved modeling the DBD discharge and chemistry, which showed that there are specific chemical pathways and plasma parameters that can be adjusted to improve the CO2 reaction efficiencies and rates. Experimental studies using the Versatile Atmospheric dielectric barrier Discharge ExpeRiment

  19. Extracurricular research activities among senior medical students in Kuwait: experiences, attitudes, and barriers

    Directory of Open Access Journals (Sweden)

    Al-Halabi B

    2014-04-01

    Full Text Available Becher Al-Halabi,1 Yousef Marwan,2 Mohammad Hasan,3 Sulaiman Alkhadhari41Department of Surgery, Mubarak Al-Kabeer Hospital, Ministry of Health, Kuwait; 2Department of Orthopaedic Surgery, Al-Razi Hospital, Al-Sabah Medical Area, Ministry of Health, Kuwait; 3Department of Radiation Oncology, Kuwait Cancer Control Center, Al-Sabah Medical Area, Ministry of Health, Kuwait; 4Department of Psychiatry, Faculty of Medicine, Health Sciences Center, Kuwait University, KuwaitBackground: Research is the foundation of scientific advancement and improvement in quality of health care, which ensures the good health of the community. The aim of this study is to explore experiences, attitudes, and barriers of medical students in Kuwait University (KU in regards to extracurricular research.Methods: A questionnaire about extracurricular research activities (ie, any research activity that is not part of the required undergraduate curriculum, such as publishing a paper, research elective, etc was distributed to 175 senior medical students (years 6 and 7. Descriptive and chi-square analyses were used to analyze the responses, considering a P-value of <0.05 as the cut-off level for significance. The main outcome was defined as taking part in any of the extracurricular research activities.Results: Of the 150 participants (response rate = 85.7%, 26 (17.3%, 68 (45.3%, 52 (34.7%, and 17 (11.3% had published their required medical school research, presented abstracts in conferences, conducted extracurricular research, and completed a research elective/course, respectively; 99 (66.0% took part in any of these activities. Participants who read medical journals regularly (81; 54% reported higher participation in extracurricular research activities than those who did not read journals (P=0.003. Improving the availability of mentors for students' extracurricular research was ranked by the participants as the most important factor to improve their participation in

  20. Multiple Intimate Partner Violence Experiences: Knowledge, Access, Utilization and Barriers to Utilization of Resources by Women of the African Diaspora.

    Science.gov (United States)

    Sabri, Bushra; Huerta, Julia; Alexander, Kamila A; St Vil, Noelle M; Campbell, Jacquelyn C; Callwood, Gloria B

    2015-11-01

    This study examined knowledge, access, utilization, and barriers to use of resources among Black women exposed to multiple types of intimate partner violence in Baltimore, Maryland and the U.S. Virgin Islands (USVI). We analyzed quantitative survey data collected by 163 women recruited from primary care, prenatal or family planning clinics in Baltimore and the USVI. In addition we analyzed qualitative data from in-depth interviews with 11 women. Quantitative data were analyzed using descriptive statistics and qualitative data were analyzed using thematic analysis. A substantial proportion of Black women with multiple types of violence experiences lacked knowledge of, did not have access to, and did not use resources. Barriers to resource use were identified at the individual, relationship, and community levels. There is need for programs to develop awareness, promote access and utilization of resources, and eliminate barriers to resource use among abused Black women.

  1. Permeable Barrier Materials for Strontium Immobilization: - UFA Determination of Hydraulic Conductivity. - Column Sorption Experiments

    National Research Council Canada - National Science Library

    Moody, T

    1996-01-01

    Selected materials were tested to emulate a permeable barrier and to examine the: (1) capture efficiency of these materials relating to the immobilization of strontium-90 and hexavalent chromium in Hanford groundwater...

  2. Barriers to implementing infection prevention and control guidelines during crises: experiences of health care professionals.

    NARCIS (Netherlands)

    Timen, A.; Hulscher, M.E.J.L.; Rust, L.; Steenbergen, J.E. van; Akkermans, R.P.; Grol, R.P.T.M.; Meer, J.W.M. van der

    2010-01-01

    BACKGROUND: Communicable disease crises can endanger the health care system and often require special guidelines. Understanding reasons for nonadherence to crisis guidelines is needed to improve crisis management. We identified and measured barriers and conditions for optimal adherence as perceived

  3. Fe-SAPONITE and Chlorite Growth on Stainless Steel in Hydrothermal Engineered Barrier Experiments

    Science.gov (United States)

    Cheshire, M. C.; Caporuscio, F. A.; McCarney, M.

    2012-12-01

    The United States recently has initiated the Used Fuel Disposition campaign to evaluate various generic geological repositories for the disposal of high-level, spent nuclear fuel within environments ranging from hard-rock, salt/clay, to deep borehole settings. Previous work describing Engineered Barrier Systems (EBS) for repositories focused on low temperature and pressure conditions. The focus of this experimental work is to characterize the stability and alteration of a bentonite-based EBS with different waste container materials in brine at higher heat loads and pressures. All experiments were run at ~150 bar and 125 to 300 C for ~1 month. Unprocessed bentonite from Colony, Wyoming was used in the experiments as the clay buffer material. The redox conditions for each system were buffered along the magnetite-iron oxygen fugacity univariant curve using Fe3O4 and Feo filings. A K-Na-Ca-Cl-based salt solution was chosen to replicate deep groundwater compositions. The experimental mixtures were 1) salt solution-clay; 2) salt solution -clay-304 stainless steel; and 3) salt solution -clay-316 stainless steel with a water/bentonite ratio of ~9. Mineralogy and aqueous geochemistry of each experiment was evaluated to monitor the reactions that took place. No smectite illitization was observed in these reactions. However, it appears that K-smectite was produced, possibly providing a precursor to illitization. It is unclear whether reaction times were sufficient for bentonite illitization at 212 and 300 C or whether conditions conducive to illite formation were obtained. The more notable clay mineral reactions occurred at the stainless steel surfaces. Authigenic chlorite and Fe-saponite grew with their basal planes near perpendicular to the steel plate, forming a 10 - 40 μm thick 'corrosion' layer. Partial dissolution of the steel plates was the likely iron source for chlorite/saponite formation; however, dissolution of the Feo/Fe3O4 may also have acted as an iron source

  4. Barriers and facilitators for return to work in cancer survivors with job loss experience: a focus group study.

    Science.gov (United States)

    van Egmond, M P; Duijts, S F A; Loyen, A; Vermeulen, S J; van der Beek, A J; Anema, J R

    2017-09-01

    Over 50% of cancer survivors lose their job or quit working. Cancer survivors who experience job loss may face different challenges regarding return to work, compared to cancer survivors with employers. This qualitative study aimed to explore barriers and facilitators for return to work in cancer survivors with job loss and in insurance physicians who assist cancer survivors in their return to work. We conducted five focus groups and one interview (cancer survivors, N = 17; insurance physicians, N = 23). Topics included, among others, experience of job loss and barriers and facilitators for return to work. Data were audio recorded and analysed using thematic analysis. Our main finding was that cancer survivors experienced a double loss: loss of job on top of loss of health. As a result, cancer survivors feared for job applications, lacked opportunities to gradually increase work ability, and faced reluctance from employers in hiring them. Insurance physicians expressed a need for more frequent and longer consultations with cancer survivors with job loss. We conclude that cancer survivors who experience double loss encounter specific barriers in the return to work process. This calls for a tailored approach regarding return to work support. © The Authors. European Journal of Cancer Care Published by John Wiley & Sons Ltd.

  5. Barriers faced by adults with intellectual disabilities who experience sexual assault: A systematic review and meta-synthesis.

    Science.gov (United States)

    McGilloway, Connie; Smith, David; Galvin, Rose

    2018-03-13

    Sexual violence is associated with significant morbidity and mortality. The incidence of sexual violence against adults with intellectual disability is significantly higher than in the general population. The aim of this systematic review and qualitative meta-synthesis was to explore the barriers faced by adults with intellectual disability in reporting sexual assault from the perspective of different stakeholders. A systematic literature search was conducted to identify relevant studies. A hermeneutic interpretive approach was employed to review and assess the methodological quality of the studies. Findings were meta-synthesized and juxtaposed to identify themes, concepts and interpretations. Thirteen studies were included. Three overarching themes emerged from an interpersonal, professional and social context, and within these domains, eight subthemes emerged as barriers to reporting sexual assault, including fear, communication, sexual knowledge and understanding, intellectual disability identification, lack of collaboration between service providers, presumption of capacity/credibility, lack of resources, myths and misconceptions. The research demonstrates that deficiencies in communication and collaboration among agencies, a lack of appropriate legislation and specific training needs and education programmes are significant barriers in the reporting of sexual assault by people with intellectual disability. These findings are not unique to adults with intellectual disability and have also been identified among people from the general population who experience sexual assault. However, adults with intellectual disability have additional barriers to overcome in order to access equal rights to healthcare, education and the legal system. © 2018 John Wiley & Sons Ltd.

  6. Emplacement of the youngest flood lava on Mars: A short, turbulent story

    Science.gov (United States)

    Jaeger, W.L.; Keszthelyi, L.P.; Skinner, J.A.; Milazzo, M.P.; McEwen, A.S.; Titus, T.N.; Rosiek, M.R.; Galuszka, D.M.; Howington-Kraus, E.; Kirk, R.L.

    2010-01-01

    Recently acquired data from the High Resolution Imaging Science Experiment (HiRISE), Context (CTX) imager, and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard the Mars Reconnaissance Orbiter (MRO) spacecraft were used to investigate the emplacement of the youngest flood-lava flow on Mars. Careful mapping finds that the Athabasca Valles flood lava is the product of a single eruption, and it covers 250,000 km2 of western Elysium Planitia with an estimated 5000-7500 km3 of mafic or ultramafic lava. Calculations utilizing topographic data enhanced with MRO observations to refine the dimensions of the channel system show that this flood lava was emplaced turbulently over a period of only a few to several weeks. This is the first well-documented example of a turbulently emplaced flood lava anywhere in the Solar System. However, MRO data suggest that this same process may have operated in a number of martian channel systems. The magnitude and dynamics of these lava floods are similar to the aqueous floods that are generally believed to have eroded the channels, raising the intriguing possibility that mechanical erosion by lava could have played a role in their incision. ?? 2009.

  7. Influence of Hydrologic Heterogeneity on Thermal-Hydrologic Behavior in Emplacement Drifts

    International Nuclear Information System (INIS)

    Y. Sun; T.A. Buscheck; Y. Hao

    2006-01-01

    Fracture networks have been characterized as highly permeable continuum within the porous rock matrix in thermal-hydrologic models used to support performance assessments of the proposed nuclear-waste repository at Yucca Mountain. Uncertainty and spatial variability of the fracture permeability are important considerations for understanding thermal-hydrologic behavior within the host rock surrounding an emplacement drift. In this paper, we conducted numerical experiments with a number of realizations of intrinsic fracture permeability and examine thermal conditions around an emplacement drift. Peak temperature and boiling duration on the drift wall are used as indices to quantify, the influence of fracture permeability. The variability of peak temperature and boiling duration resulting from small-scale fracture-permeability heterogeneity is compared with the variability resulting from variability of host-rock thermal conductivity and infiltration flux. An examination of rock dryout and condensate drainage shows that small-scale heterogeneity in fracture permeability results in a relatively small range in dryout volume and does not prevent the shedding of condensate through the pillar-separating emplacement drifts

  8. Postclosure performance assessment of the SCP [Site Characterization Plan] conceptual design for horizontal emplacement: Revision 1

    International Nuclear Information System (INIS)

    1987-08-01

    This report is a preliminary postclosure performance assessment of the repository design specified in the Site Characterization Plan Conceptual Design Report (SCP-CDR) for horizontal emplacement of high-level nuclear waste. At the time that these analyses were done, horizontal emplacement was the preferred orientation for the waste packages but vertical emplacement is now the reference design. This assessment consists of (1) a review of the regulatory requirements and strategy to demonstrate compliance with these requirements, (2) an analysis of the performance of the total repository system, (3) an analysis of the thermomechanical behavior of the repository, (4) an analysis of brine mobility in the repository, (5) an analysis of the waste package performance, (6) an analysis of the performance of seals, and (7) comments on the sensitivity of the various performance measures to uncertainties in the data and models. These are preliminary analyses and, in most cases, involve bounding calculations of the repository behavior. They have several purposes including (1) assessing how well this conceptual design ''measures up'' against requirements, (2) gaining experience in implementing the performance assessment strategy and tools and thereby learning where improvements are needed, (3) helping to identify needed data, and (4) helping to indicate required design modifications. 26 refs., 40 figs., 20 tabs

  9. What Barriers and Facilitators Do School Nurses Experience When Implementing an Obesity Intervention?

    Science.gov (United States)

    Schroeder, Krista; Smaldone, Arlene

    2017-01-01

    A recent evaluation of a school nurse-led obesity intervention demonstrated a 5% implementation rate. The purpose of this study was to explore school nurses' perceived barriers to and facilitators of the intervention in order to understand reasons for the low implementation rate. Methods included semi-structured individual interviews with school…

  10. Opportunities or Barriers? The Experiences of Disadvantaged Older Jobseekers Participating in Training

    Science.gov (United States)

    Meyers, Rebecca

    2016-01-01

    In Australia and other OECD countries, increasing the labour force participation rate of older adults (45-64 years) is seen as a primary strategy to address the current demographic challenges brought about by an ageing population and the retirement of skilled workers. Not all older adults have current workplace skills, yet barriers which include…

  11. Migrant Sexual Health Help-Seeking and Experiences of Stigmatization and Discrimination in Perth, Western Australia: Exploring Barriers and Enablers.

    Science.gov (United States)

    Agu, Josephine; Lobo, Roanna; Crawford, Gemma; Chigwada, Bethwyn

    2016-05-11

    Increasing HIV notifications amongst migrant and mobile populations to Australia is a significant public health issue. Generalizations about migrant health needs and delayed or deterred help-seeking behaviors can result from disregarding the variation between and within cultures including factors, such as drivers for migration and country of birth. This study explored barriers and enablers to accessing sexual health services, including experiences of stigma and discrimination, within a purposive sample of sub-Saharan African, Southeast Asian, and East Asian migrants. A qualitative design was employed using key informant interviews and focus group discussions. A total of 45 people with ages ranging from 18 to 50 years, participated in focus group discussions. Common barriers and enablers to help seeking behaviors were sociocultural and religious influence, financial constraints, and knowledge dissemination to reduce stigma. Additionally, common experiences of stigma and discrimination were related to employment and the social and self-isolation of people living with HIV. Overcoming barriers to accessing sexual health services, imparting sexual health knowledge, recognizing variations within cultures, and a reduction in stigma and discrimination will simultaneously accelerate help-seeking and result in better sexual health outcomes in migrant populations.

  12. Migrant Sexual Health Help-Seeking and Experiences of Stigmatization and Discrimination in Perth, Western Australia: Exploring Barriers and Enablers

    Directory of Open Access Journals (Sweden)

    Josephine Agu

    2016-05-01

    Full Text Available Increasing HIV notifications amongst migrant and mobile populations to Australia is a significant public health issue. Generalizations about migrant health needs and delayed or deterred help-seeking behaviors can result from disregarding the variation between and within cultures including factors, such as drivers for migration and country of birth. This study explored barriers and enablers to accessing sexual health services, including experiences of stigma and discrimination, within a purposive sample of sub-Saharan African, Southeast Asian, and East Asian migrants. A qualitative design was employed using key informant interviews and focus group discussions. A total of 45 people with ages ranging from 18 to 50 years, participated in focus group discussions. Common barriers and enablers to help seeking behaviors were sociocultural and religious influence, financial constraints, and knowledge dissemination to reduce stigma. Additionally, common experiences of stigma and discrimination were related to employment and the social and self-isolation of people living with HIV. Overcoming barriers to accessing sexual health services, imparting sexual health knowledge, recognizing variations within cultures, and a reduction in stigma and discrimination will simultaneously accelerate help-seeking and result in better sexual health outcomes in migrant populations.

  13. The Lattice and Thermal Radiation Conductivity of Thermal Barrier Coatings: Models and Experiments

    Science.gov (United States)

    Zhu, Dongming; Spuckler, Charles M.

    2010-01-01

    The lattice and radiation conductivity of ZrO2-Y2O3 thermal barrier coatings was evaluated using a laser heat flux approach. A diffusion model has been established to correlate the coating apparent thermal conductivity to the lattice and radiation conductivity. The radiation conductivity component can be expressed as a function of temperature, coating material scattering, and absorption properties. High temperature scattering and absorption of the coating systems can be also derived based on the testing results using the modeling approach. A comparison has been made for the gray and nongray coating models in the plasma-sprayed thermal barrier coatings. The model prediction is found to have a good agreement with experimental observations.

  14. Experiences and Perceptions of Barriers to Health Services for Elderly in Rural Namibia

    Directory of Open Access Journals (Sweden)

    Gert Van Rooy

    2015-07-01

    Full Text Available We investigate barriers to accessing health facilities (e.g., transportation and cost of services and health service delivery barriers (e.g., timeliness of services scheduling of appointments, language that the literature suggest are operative. Semistructured interviews were utilized with respondents in three purposefully selected regional research sites in Namibia. All questions were translated into local languages. It is found that although many senior citizens appreciate the use of modern health care and are exempted from paying health care consultation fees, they still prefer to use traditional health medicine because of the long distance to health care facilities, which when they decide to travel translates into high transportation costs. Referrals to hospitals become very expensive. There is a need to consider the unique issues (extended family system affecting access to health care for elderly people in Namibia to achieve equitable access to health care services.

  15. Culture as a barrier to rural women's entrepreneurship: experience from Zimbabwe.

    Science.gov (United States)

    Chitsike, C

    2000-03-01

    This article identifies the important issues addressed by programs and projects that are aimed at promoting women's equality through entrepreneurship and suggests several actions for future focus of gender programs and training. Culture was seen as a barrier to the self-confident and autonomous economic activities of women in Zimbabwe. Likewise, structural barriers such as lack of marketable skills, time and ability to travel, land and assets, education, and position as primary family providers all compounded to the problem of entrepreneurship among women. Establishment of policy approaches for women like vocational skills training augmented by training in business skills and marketing, however, are insufficient since it failed to discuss and transfer behavioral skills necessary to make one an entrepreneur. To conclude, programs must be designed to empower personal skills and self-awareness, as well as address the constraints to entrepreneurship, and macroeconomic policy change.

  16. Effect of repository underground ventilation on emplacement drift temperature control

    International Nuclear Information System (INIS)

    Yang, H.; Sun, Y.; McKenzie, D.G.; Bhattacharyya, K.K.

    1996-01-01

    The repository advanced conceptual design (ACD) is being conducted by the Civilian Radioactive Waste Management System, Management ampersand Operating Contractor. Underground ventilation analyses during ACD have resulted in preliminary ventilation concepts and design methodologies. This paper discusses one of the recent evaluations -- effects of ventilation on emplacement drift temperature management

  17. Emplacement kinematics of nepheline syenites from the Terrane ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Nepheline syenite plutons emplaced within the Terrane Boundary Shear Zone of the Eastern Ghats. Mobile Belt west of Khariar in northwestern Orissa are marked by a well-developed magmatic fabric including magmatic foliation, mineral lineations, folds and S-C fabrics. The minerals in the plutons, namely microcline ...

  18. Estimation of emplacement temperatures of pyroclastic flows using H/C ratios of carbonized wood

    Science.gov (United States)

    Sawada, Y.; Sampei, Y.; Hyodo, M.; Yagami, T.; Fukue, M.

    2000-12-01

    Laboratory experiments aimed at allowing estimation of emplacement temperatures of pyroclastic deposits flows using H/C ratios of entrained carbonized wood were carried by simulating the thermal conditions in pyroclastic flows. Live wood cuttings of four tree genera (Cryptomeria, Pinus, Quercus and Gonystylus) were implanted in volcanic ash heated in an electric furnace. In one group of experiments, wood samples were inserted into the ash in separate runs at temperatures ranging from 238 to 714°C, and then slowly cooled. In a second group, samples were held at temperatures between 241 and 743°C for one, three or five days. H/C ratios of the carbonized woods produced were then determined by combustion analysis. No systematic differences in H/C ratios were observed between genera at given temperatures. H/C ratios from the first group of experiments show a strong correlation with temperature, yielding the equation log T(°C)=2.50-0.530 log (H/C) where H/C ratios are 300°C. Similar relations are also shown by the second group, although the equations produced differ with time of maximum heating. The relations between H/C ratios and temperature from the experiments were tested by analysis of natural carbonized wood fragments from Holocene pyroclastic flow deposits, coupled with independent emplacement temperature estimation from paleomagnetic blocking temperatures of clasts within the flows. The two methods produced comparable results, suggesting that the H/C thermometer is a simple and reliable method for estimating maximum emplacement temperatures of pyroclastic flows. Cooling rates can also be approximated when combined with paleomagnetic studies.

  19. Experiences of leaders in the implementation of Lean in a teaching hospital--barriers and facilitators in clinical practices: a qualitative study.

    NARCIS (Netherlands)

    Aij, K.H.; Simons, F.E.; Widdershoven, G.A.; Visse, M.A.

    2013-01-01

    Objectives: To date, experiences of leaders in the implementation of Lean after a Lean Training Programme have not been systematically investigated within teaching hospitals. Existing studies have identified barriers and facilitators only from an improvement programme perspective and have not

  20. Health Care Experiences and Perceived Barriers to Health Care Access: A Qualitative Study Among African Migrants in Guangzhou, Guangdong Province, China.

    Science.gov (United States)

    Lin, Lavinia; Brown, Katherine B; Yu, Fan; Yang, Jingqi; Wang, Jason; Schrock, Joshua M; Bodomo, Adams B; Yang, Ligang; Yang, Bin; Nehl, Eric J; Tucker, Joseph D; Wong, Frank Y

    2015-10-01

    Guangzhou, one of China's largest cities and a main trading port in South China, has attracted many African businessmen and traders migrating to the city for financial gains. Previous research has explored the cultural and economic roles of this newly emerging population; however, little is known about their health care experiences while in China. Semi-structured interviews and focus groups were used to assess health care experiences and perceived barriers to health care access among African migrants in Guangzhou, China. Overall, African migrants experienced various barriers to accessing health care and were dissatisfied with local health services. The principal barriers to care reported included affordability, legal issues, language barriers, and cultural differences. Facing multiple barriers, African migrants have limited access to care in Guangzhou. Local health settings are not accustomed to the African migrant population, suggesting that providing linguistically and culturally appropriate services may improve access to care for the migrants.

  1. Medical students' experience of performing female pelvic examinations: Opportunities and barriers.

    Science.gov (United States)

    Bhoopatkar, Harsh; Wearn, Andy; Vnuk, Anna

    2017-10-01

    Teaching and learning female pelvic examination within the undergraduate medical curriculum offers some potential challenges. One such is the extent to which students are provided practice opportunities with patients in the clinical setting. To quantify how many pelvic examinations, on real patients, have been performed by medical students at the point of graduation, and to explore opportunities and barriers to performing these examinations. A retrospective study using a self-completed, anonymous, electronic survey was developed as part of a multi-centre study. Data were collected in the immediate period after graduation from the medical programs at the University of Auckland and Flinders University in 2013. An ordinal set of range categories was used for recording numbers of examinations. The combined response rate for the survey was 42.9% (134/312). The median range category for the number of pelvic examinations performed in patients who were not in labour was 6-9 and in labour was 2-3. Thirty-three percent of medical students had never performed a pelvic examination in labour. Male medical students performed significantly fewer pelvic examinations compared with female students. Self-reported barriers to performing the pelvic exam include: gender of the student, 'gate-keeping' by other health professionals, lack of confidence and patient factors. The majority of medical students have performed several pelvic examinations on real patients at graduation. Male gender and access being limited by midwives were the main barriers to performing female pelvic examinations. Medical curricula need to address these issues in the learning environment. © 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  2. Barriers and facilitators to integrating care: experiences from the English Integrated Care Pilots

    Directory of Open Access Journals (Sweden)

    Tom Ling

    2012-07-01

    Full Text Available Background. In 2008, the English Department of Health appointed 16 'Integrated Care Pilots' which used a range of approaches to provide better integrated care. We report qualitative analyses from a three year multi-method evaluation to identify barriers and facilitators to successful integration of care.  Theory and methods. Data were analysed from transcripts of 213 in-depth staff interviews, and from semi-structured questionnaires (the 'Living Document' completed by staff in pilot sites at six points over a two-year period. Emerging findings were therefore built from 'bottom up' and grounded in the data. However, we were then interested in how these findings compared and contrasted with more generic analyses. Therefore after our analyses were complete we then systematically compared and contrasted the findings with the analysis of barriers and facilitators to quality improvement identified in a systematic review by Kaplan et al (2010 and the analysis of more micro-level shapers of behaviour found in Normalisation Process Theory (May et al 2007. Neither of these approaches claims to be full blown theories but both claim to provide mid-range theoretical arguments which may be used to structure existing data and which can be undercut or reinforced by new data. Results and discussion. Many barriers and facilitators to integrating care are those of any large scale organisational change. These include issues relating to leadership, organisational culture, information technology, physician involvement, and availability of resources. However, activities which appear particularly important for delivering integrated care include personal relationships between leaders in different organisations, the scale of planned activities, governance and finance arrangements, support for staff in new roles, and organisational and staff stability. We illustrate our analyses with a 'routemap' which identifies questions that providers may wish to consider when

  3. [Overcoming language barriers with telephone interpreters: first experiences at a German children's hospital].

    Science.gov (United States)

    Langer, Thorsten; Wirth, Stefan

    2014-01-01

    Language barriers in the care for patients with limited German language proficiency contribute to impaired quality of care, more frequent medical errors and decreased patient satisfaction. However, professional interpreters are not systematically used in Germany. We conducted a pilot study in a German paediatric hospital to explore the demand for an interpreter by conducting a survey among parents and to test the use of telephone interpreters. Eight percent of the respondents said they were interested in interpreter support. All physicians and parents using a telephone interpreter were very satisfied with the quality and the organisation of the service. Copyright © 2013. Published by Elsevier GmbH.

  4. Possibilities and Barriers for Energy Conservation in a Liberalised Electricity Market: Danish Utility Experiences

    DEFF Research Database (Denmark)

    Meyer, Niels I

    1999-01-01

    development.Commercial competition has a short time horizon and a goal function of profit maximizing. In contrast to this, creation of a sustainable development requires long time horizons and comprehensive societal planning and regulation.This paper analyses the possibilities and barriers for promoting...... a sustainable energy development in efficiency and energy conservation. The electric utilities play an important role in this relation, but their priority is of commercial nature rather than concern for the environment. This dilemma is analyzed in more detail in the paper....

  5. Effect of barrier layers in burnthrough experiments with 351-nm laser illumination

    International Nuclear Information System (INIS)

    Delettrez, J.; Bradley, D.K.; Jaanimagi, P.A.; Verdon, C.P.

    1990-01-01

    The time-resolved x-ray emission is measured from spherical targets consisting of glass shells overcoated with plastic in which thin signature layers are embedded. These targets are illuminated at 351 nm by the 24-beam OMEGA laser system at the Laboratory for Laser Energetics of the University of Rochester. We measure a large burnthrough rate for bare plastic targets that can only be replicated in one-dimensional hydrodynamic simulations with laser intensities in excess of ten times the nominal intensity. We observe that the burnthrough times are affected by the presence of a thin outer coating (barrier layer). The burnthrough times depend strongly on the barrier-layer material and thickness, whereas one-dimensional simulation results predict only a small effect. Several processes are considered to explain these results: illumination nonuniformity, early shinethrough of the laser light through the plastic, prepulses, filamentation, self-focusing of hot spots, and the Rayleigh-Taylor instability. We conclude that mixing due to the Rayleigh-Taylor instability, enhanced by early shinethrough, is the most probable cause of the observed large burnthrough rates

  6. Comparative study of waste emplacement configurations for the nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Lee, Y.J.; Julien, H.L.; Schmidt, B.; Henry, K.H.; Parsons, Brinckerhoff, Quade and Douglas, Inc., San Francisco, CA; Rockwell Hanford Operations, Richland, WA)

    1985-01-01

    Various alternative waste emplacement concepts were evaluated and compared in order to select a waste emplacement configuration for the Nuclear Waste Repository in Basalt (NWRB). Based on screening of 51 feasible configurations, 11 alternative waste emplacement concepts warranted further evaluation. All of these configurations were analyzed in sufficient detail to assess the technical feasibility of each configuration and to allow a comparative evaluation. Based on the evaluation, the alternatives of greatest merit are, in order of preference: horizontal short-hole emplacements with single canisters close to room walls, with holes either at a 90 0 or 45 0 angle to the room; angled short-hole emplacement in the floor; asymmetric, long-hole, horizontal multiple canister emplacement; and angled short-hole emplacement off the floor corner. Other alternatives, including an in-room and a vertical emplacement configuration, were found to have significantly lower merit. This paper summarizes the technical evaluations that have led to this conclusion

  7. Barriers and challenges in clinical ethics consultations: the experiences of nine clinical ethics committees.

    Science.gov (United States)

    Pedersen, Reidar; Akre, Victoria; Førde, Reidun

    2009-10-01

    Clinical ethics committees have recently been established in nearly all Norwegian hospital trusts. One important task for these committees is clinical ethics consultations. This qualitative study explores significant barriers confronting the ethics committees in providing such consultation services. The interviews with the committees indicate that there is a substantial need for clinical ethics support services and, in general, the committee members expressed a great deal of enthusiasm for the committee work. They also reported, however, that tendencies to evade moral disagreement, conflict, and 'outsiders' are common in the hospitals. Sometimes even the committees comply with some of these tendencies. The committees agree that there is a need to improve their routines and procedures, clarify the committees' profile and field of responsibility, to make the committees well-known, to secure adequate operating conditions, and to develop organizational integration and support. Various strategies to meet these challenges on a local, regional or national level are also explored in this paper.

  8. Operational considerations in drift emplacement of waste packages

    International Nuclear Information System (INIS)

    Benton, H.A.

    1993-01-01

    This paper discusses the operational considerations as well as the advantages and disadvantages of emplacing waste packages in drifts in a repository. The considerations apply particularly to the potential repository for spent nuclear fuel and high-level waste glass at Yucca Mountain, although most of the considerations and the advantages and disadvantages discussed in this paper do not necessarily represent the official views of the DOE or of the Management and Operations Contractor, since most of these considerations are still under active discussion and the final decisions will not be made for some time - perhaps years. This paper describes the issues, suggests some principles upon which decisions should be based, and states some of the most significant advantages and disadvantages of the emplacement modes, and the associated waste package types and thermal loadings

  9. Pre-college experiences in and out of the classroom lead to first-year barriers

    Science.gov (United States)

    Reed, D. E.; Kaplita, E.; McKenzie, D. A.; Jones, R.; May, L. W.

    2015-12-01

    Students often enter college with preconceived notions about science. These misconceptions, coupled with a potential for a limited number of science classes during college for non-science majors, can make correcting misconceptions a very daunting challenge. In order to efficiently commutate climate science in a limited number of science classes, instructors need to understand the student experiences that have created their preconceived notions. In many cases, a lack of data about student's experiences leads to instructors simply guessing at how students are thinking about and interacting with science. Student surveys were used in our work to quantify pre-college experiences, both in and out of the classroom, in order to examine the connection to both academic major and choice of college or university students attended. Surveys were given to nearly 400 students across 4 different schools in the Oklahoma City Metro area. The location of students (rural or urban) affected science experiences as well as what types of actives (local libraries, museums, or parks) were available to the students. Connections between the timing of experience (elementary through high school) and the type of experience (in the classroom, with family/friends, or on their own) may influence choice of college or university as well as academic major. A better understating of positive student science experiences will allow instructors to better tailor their pedagogy and facilitate better connections between climate science and students.

  10. Subsurface barrier verification technologies, informal report

    International Nuclear Information System (INIS)

    Heiser, J.H.

    1994-06-01

    One of the more promising remediation options available to the DOE waste management community is subsurface barriers. Some of the uses of subsurface barriers include surrounding and/or containing buried waste, as secondary confinement of underground storage tanks, to direct or contain subsurface contaminant plumes and to restrict remediation methods, such as vacuum extraction, to a limited area. To be most effective the barriers should be continuous and depending on use, have few or no breaches. A breach may be formed through numerous pathways including: discontinuous grout application, from joints between panels and from cracking due to grout curing or wet-dry cycling. The ability to verify barrier integrity is valuable to the DOE, EPA, and commercial sector and will be required to gain full public acceptance of subsurface barriers as either primary or secondary confinement at waste sites. It is recognized that no suitable method exists for the verification of an emplaced barrier's integrity. The large size and deep placement of subsurface barriers makes detection of leaks challenging. This becomes magnified if the permissible leakage from the site is low. Detection of small cracks (fractions of an inch) at depths of 100 feet or more has not been possible using existing surface geophysical techniques. Compounding the problem of locating flaws in a barrier is the fact that no placement technology can guarantee the completeness or integrity of the emplaced barrier. This report summarizes several commonly used or promising technologies that have been or may be applied to in-situ barrier continuity verification

  11. Oxidation of volatile organic compound vapours by potassium permanganate in a horizontal permeable reactive barrier under unsaturated conditions: experiments and modeling

    NARCIS (Netherlands)

    Ghareh Mahmoodlu, Mojtaba

    2014-01-01

    In this research we evaluated the potential of using solid potassium permanganate to create a horizontal permeable reactive barrier (HPRB) for oxidizing VOC vapours in the unsaturated zone. We have performed batch experiments, short column, and long column experiments, and have fully analyzed the

  12. Identifying barriers on Facebook interaction: An Experience with Southern Patagonia Older Adults

    Directory of Open Access Journals (Sweden)

    Diego Vilte

    2015-09-01

    In this work we present an experience with elders and their interaction with Facebook. To this end we made a workshop which allowed us observing the way in which participants executed proposed activities and then we evaluated usability of the application.

  13. Understanding and Overcoming Barriers: Learning Experiences of Undergraduate Sudanese Students at an Australian University

    Science.gov (United States)

    Gately, Natalie Jane; Ellis, Suzanne; Britton, Katherine; Fleming, Tina

    2017-01-01

    An increase in migration of Sudanese and South Sudanese people to Australia due to civil unrest in their home country has increased the numbers of Sudanese students at university. Migrant experiences, particularly those of English as a second language, can impact negatively on education and learning. Inconsistencies between student scores on…

  14. Latina/o Food Industry Employees' Work Experiences: Work Barriers, Facilitators, Motivators, Training Preferences, and Perceptions

    Science.gov (United States)

    Kanagui-Munoz, Marlen; Garriott, Patton O.; Flores, Lisa Y.; Cho, Seonghee; Groves, James

    2012-01-01

    The present study explored the work experiences, job satisfaction, and work behaviors of Latina/o restaurant workers. A total of 10 semistructured focus group (N = 75) interviews were conducted in the Midwest and Southwest. Data were analyzed using a combination of Consensual Qualitative Research (CQR; Hill et al., 2005; Hill, Thompson, &…

  15. Final disposal in deep boreholes using multiple geological barriers. Digging deeper for safety. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Bracke, Guido; Hurst, Stephanie; Merkel, Broder; Mueller, Birgit; Schilling, Frank

    2016-03-15

    The proceedings of the workshop on final disposal in deep boreholes using multiple geological barriers - digging deeper for safety include contributions on the following topics: international status and safety requirements; geological and physical barriers; deep drilling - shaft building; technical barriers and emplacement technology for high P/T conditions; recovery (waste retrieval); geochemistry and monitoring.

  16. Attenuation of pyrite oxidation with a fly ash pre-barrier: Reactive transport modelling of column experiments

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lopez, R.; Cama, J.; Nieto, J.M.; Ayora, C.; Saaltink, M.W. [University of Huelva, Huelva (Spain). Dept. of Geology

    2009-09-15

    Conventional permeable reactive barriers (PRBs) for passive treatment of groundwater contaminated by acid mine drainage (AMD) use limestone as reactive material that neutralizes water acidity. However, the limestone-alkalinity potential ceases as inevitable precipitation of secondary metal-phases on grain surfaces occurs, limiting its efficiency. In the present study, fly ash derived from coal combustion is investigated as an alternative alkalinity generating material for the passive treatment of AMD using solution-saturated column experiments. Unlike conventional systems, the utilization of fly ash in a pre-barrier to intercept the non-polluted recharge water before this water reacts with pyrite-rich wastes is proposed. Chemical variation in the columns was interpreted with the reactive transport code RETRASO. In parallel, kinetics of fly ash dissolution at alkaline pH were studied using flow-through experiments and incorporated into the model. In a saturated column filled solely with pyritic sludge-quartz sand (1: 10), oxidation took place at acidic conditions (pH 3.7). According to SO{sub 4}{sup 2-} release and pH, pyrite dissolution occurred favourably in the solution-saturated porous medium until dissolved O{sub 2} was totally consumed. In a second saturated column, pyrite oxidation took place at alkaline conditions (pH 10.45) as acidity was neutralized by fly ash dissolution in a previous level. At this pH Fe release from pyrite dissolution was immediately depleted as Fe-oxy(hydroxide) phases that precipitated on the pyrite grains, forming Fe-coatings (microencapsulation). With time, pyrite microencapsulation inhibited oxidation in practically 97% of the pyritic sludge. Rapid pyrite-surface passivation decreased its reactivity, preventing AMD production in the relatively short term.

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

    International Nuclear Information System (INIS)

    1997-01-01

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

  18. Emplacement of zero-valent metal for remediation of deep contaminant plumes

    International Nuclear Information System (INIS)

    Hubble, D.W.; Gillham, R.W.; Cherry, J.A.

    1997-01-01

    Some groundwater plumes containing chlorinated solvent contaminants are found to be so deep that current in situ remediation technologies cannot be economically applied. Also, source zones are often found to be too deep for removal or inaccessible due to surface features. Plumes emanating from these sources require containment or treatment. Containment technologies are available for shallow sites (< 15 m) and are being developed for greater depths. However, it is important to advance the science of reactive treatment - both for cut off of plumes and to contain and treat source zones. Zero-valent metal technology has been used for remediation of solvent plumes at sites in Canada, the UK and at several industrial and military sites in the USA. To date, all of the plumes treated with zero-valent metal (granular iron) have been at depths less than 15 m. This paper gives preliminary results of research into methods to emplace granular iron at depths in the range of 15 to 60 m. The study included review of available and emerging methods of installing barrier or reactive material and the selection, preliminary design and costing of several methods. The design of a treatment system for a 122 m wide PCE plume that, immediately down gradient from its source, extends from a depth of 24 to 37 m below the ground surface is used as a demonstration site. Both Permeable Reactive Wall and Funnel-and-Gate trademark systems were considered. The emplacement methods selected for preliminary design and costing were slurry wall, driven/vibrated beam, deep soil mixing and hydrofracturing injection. For each of these methods, the iron must be slurried for ease of pumping and placement using biodegradable polymer viscosifiers that leave the iron reactive

  19. Experiments on thermo-hydro-mechanical behaviour of Opalinus Clay at Mont Terri rock laboratory, Switzerland

    Directory of Open Access Journals (Sweden)

    Paul Bossart

    2017-06-01

    Full Text Available Repositories for deep geological disposal of radioactive waste rely on multi-barrier systems to isolate waste from the biosphere. A multi-barrier system typically comprises the natural geological barrier provided by the repository host rock – in our case the Opalinus Clay – and an engineered barrier system (EBS. The Swiss repository concept for spent fuel and vitrified high-level waste (HLW consists of waste canisters, which are emplaced horizontally in the middle of an emplacement gallery and are separated from the gallery wall by granular backfill material (GBM. We describe here a selection of five in-situ experiments where characteristic hydro-mechanical (HM and thermo-hydro-mechanical (THM processes have been observed. The first example is a coupled HM and mine-by test where the evolution of the excavation damaged zone (EDZ was monitored around a gallery in the Opalinus Clay (ED-B experiment. Measurements of pore-water pressures and convergences due to stress redistribution during excavation highlighted the HM behaviour. The same measurements were subsequently carried out in a heater test (HE-D where we were able to characterise the Opalinus Clay in terms of its THM behaviour. These yielded detailed data to better understand the THM behaviours of the granular backfill and the natural host rock. For a presentation of the Swiss concept for HLW storage, we designed three demonstration experiments that were subsequently implemented in the Mont Terri rock laboratory: (1 the engineered barrier (EB experiment, (2 the in-situ heater test on key-THM processes and parameters (HE-E experiment, and (3 the full-scale emplacement (FE experiment. The first demonstration experiment has been dismantled, but the last two ones are on-going.

  20. Thermally-assisted Magma Emplacement Explains Restless Calderas

    Science.gov (United States)

    Amoruso, A.; Crescentini, L.; D'Antonio, M.; Acocella, V.

    2017-12-01

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei, Italy, which is the best-known, yet most dangerous calderas, lying to the west of Naples and restless since the 1950s at least.Our elaboration of the geodetic data indicates that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust.Our thermal models show that the repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth 3 ka before the last eruption and, in turn, contributed to maintain the thermal anomaly itself. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks.Available information at other calderas highlights similarities to Campi Flegrei, in the pattern and cause of unrest. All monitored restless calderas have either geodetically (Yellowstone, Aira Iwo-Jima, Askja, Fernandina and, partly, Long Valley) or geophysically (Rabaul, Okmok) detected sill-like intrusions inducing repeated unrest. Some calderas (Yellowstone, Long Valley) also show stable deformation pattern, where inflation insists on and mimics the resurgence uplift. The common existence of sill-like sources, also responsible for stable deformation patterns, in restless calderas suggests close similarities to Campi Flegrei. This suggests a wider applicability of our model of thermally-assisted sill emplacement, to be tested by future studies to better understand not only the dynamics of restless

  1. Adoption barriers for electric vehicles: Experiences from early adopters in Sweden

    International Nuclear Information System (INIS)

    Vassileva, Iana; Campillo, Javier

    2017-01-01

    Electric vehicles are considered as one of the most effective technologies for reducing current greenhouse gas emissions from the transport sector. Although in many countries, local and national governments have introduced incentives and subsidies to facilitate the electric vehicle market penetration, in Sweden, such benefits have been limited. Results from a survey carried out among private owners of electric vehicles are presented in this paper, including the analysis of the respondents socio-demographic characteristics, reasons for choosing an electric vehicle, charging locations and driving preferences, among others. The main results characterize current electric vehicle drivers as male, well-educated, with medium-high income; electric vehicles are used mainly for private purposes and charged at home during night time. Furthermore, the paper presents an analysis of the impact of large-scale penetration of electric vehicles on existing power distribution systems. The findings presented in this paper provide important insights for assuring a sustainable large-scale penetration of electric vehicles by learning from the experiences of early adopters of the technology and by analyzing the impact of different EV penetration scenarios on the power distribution grid. - Highlights: • A survey was conducted on EV owners' experience and characteristics. • Impact on the power system of large-scale EV adoption was analyzed. • Feedback from EV owners should be used to engage potential users. • Coordinated smart charging is needed to reduce power grid impact. • Coordinated smart charging is required to minimize disturbances on the power grid.

  2. An examination of how women and underrepresented racial/ethnic minorities experience barriers in biomedical research and medical programs

    Science.gov (United States)

    Chakraverty, Devasmita

    Women in medicine and biomedical research often face challenges to their retention, promotion, and advancement to leadership positions (McPhillips et al., 2007); they take longer to advance their careers, tend to serve at less research-intensive institutions and have shorter tenures compared to their male colleagues (White, McDade, Yamagata, & Morahan, 2012). Additionally, Blacks and Hispanics are the two largest minority groups that are vastly underrepresented in medicine and biomedical research in the United States (AAMC, 2012; NSF, 2011). The purpose of this study is to examine specific barriers reported by students and post-degree professionals in the field through the following questions: 1. How do women who are either currently enrolled or graduated from biomedical research or medical programs define and make meaning of gender-roles as academic barriers? 2. How do underrepresented groups in medical schools and biomedical research institutions define and make meaning of the academic barriers they face and the challenges these barriers pose to their success as individuals in the program? These questions were qualitatively analyzed using 146 interviews from Project TrEMUR applying grounded theory. Reported gender-role barriers were explained using the "Condition-Process-Outcome" theoretical framework. About one-third of the females (across all three programs; majority White or Black between 25-35 years of age) reported gender-role barriers, mostly due to poor mentoring, time constraints, set expectations and institutional barriers. Certain barriers act as conditions, causing gender-role issues, and gender-role issues influence certain barriers that act as outcomes. Strategies to overcome barriers included interventions mostly at the institutional level (mentor support, proper specialty selection, selecting academia over medicine). Barrier analysis for the two largest URM groups indicated that, while Blacks most frequently reported racism, gender barriers

  3. Colonisation in social species: the importance of breeding experience for dispersal in overcoming information barriers

    Science.gov (United States)

    Payo-Payo, A.; Genovart, M.; Sanz-Aguilar, A.; Greño, J. L.; García-Tarrasón, M.; Bertolero, A.; Piccardo, J.; Oro, D.

    2017-02-01

    Studying colonisation is crucial to understand metapopulations, evolutionary ecology and species resilience to global change. Unfortunately, few empirical data are available because field monitoring that includes empty patches at large spatiotemporal scales is required. We examine the colonisation dynamics of a long-lived seabird over 34 years in the western Mediterranean by comparing population and individual data from both source colony and the newly-formed colonies. Since social information is not available, we hypothesize that colonisation should follow particular dispersal dynamics and personal information must be crucial in decision making. We test if adverse breeding conditions trigger colonisation events, if personal information plays a role in colonisation and if colonisers experience greater fitness. Our results show a temporal mismatch between colonisation events and both density-dependence and perturbations at the source colony, probably because colonisers needed a longer prospecting period to compensate for the lack of public information. Colonisers were mostly experienced individuals gaining higher breeding success in the new colony. Our results highlight the demographic value that experienced individuals can have on metapopulation dynamics of social long-lived organisms.

  4. Emplacement and Subsidence of Indian Ocean Plateaus and Submarine Ridges

    Science.gov (United States)

    Coffin, Millard F.

    Ocean Drilling Program, Deep Sea Drilling Project, and industrial borehole results from Indian Ocean plateaus and submarine ridges help to constrain their subsidence histories. I use a simple Airy isostatic model to calculate basement depths at ODP sites in the absence of sediment, and then backtrack these sites using previously determined age-depth relationships for oceanic lithosphere to determine the original depth or elevation of the sites. Resulting subsidence curves for each site were then checked by examining sedimentologic and biostratigraphic evidence for when each site subsided below shelf depths. The analysis suggests that thermal subsidence has been the dominant tectonic process affecting Indian Ocean plateaus and submarine ridges following emplacement. I conclude that large portions of these features were emplaced and began subsiding well above sea level, similar to large igneous provinces (LIPs) worldwide today. This resulted in significant subaerial erosion and redeposition of volcanic material mixed with biogenic sediment, and a gradual development of facies from terrestrial through terrigenous to shallow water and pelagic, resulting in a sedimentary record with both continental and oceanic characteristics.

  5. Natural and Synthetic Barriers to Immobilize Radionuclides

    International Nuclear Information System (INIS)

    Um, W.

    2011-01-01

    The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

  6. 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)

  7. Managing in the Contemporary World: Rape Victims' and Supporters' Experiences of Barriers within the Police and the Health Care System in Tanzania

    Science.gov (United States)

    Muganyizi, Projestine S.; Nystrom, Lennarth; Axemo, Pia; Emmelin, Maria

    2011-01-01

    Grounded theory guided the analysis of 30 in-depth interviews with raped women and community members who had supported raped women in their contact with the police and health care services in Tanzania. The aim of this study was to understand and conceptualize the experiences of the informants by creating a theoretical model focusing on barriers,…

  8. Did the suicide barrier work after all? Revisiting the Bloor Viaduct natural experiment and its impact on suicide rates in Toronto.

    Science.gov (United States)

    Sinyor, Mark; Schaffer, Ayal; Redelmeier, Donald A; Kiss, Alex; Nishikawa, Yasunori; Cheung, Amy H; Levitt, Anthony J; Pirkis, Jane

    2017-06-19

    This research aims to determine the long-term impact of the Bloor Street Viaduct suicide barrier on rates of suicide in Toronto and whether media reporting had any impact on suicide rates. Natural experiment. City of Toronto, Canada; records at the chief coroner's office of Ontario 1993-2003 (11 years before the barrier) and 2004-2014 (11 years after the barrier). 5403 people who died by suicide in the city of Toronto. Changes in yearly rates of suicide by jumping at Bloor Street Viaduct, other bridges including nearest comparison bridge and walking distance bridges, and buildings, and by other means. Suicide rates at the Bloor Street Viaduct declined from 9.0 deaths/year before the barrier to 0.1 deaths/year after the barrier (incidence rate ratio (IRR) 0.005, 95% CI 0.0005 to 0.19, p=0.002). Suicide deaths from bridges in Toronto also declined significantly (IRR 0.53, 95% CI 0.40 to 0.71, psuicide at the Bloor Street Viaduct were associated with an increase in suicide-by-jumping from bridges the following year. The current study demonstrates that, over the long term, suicide-by-jumping declined in Toronto after the barrier with no associated increase in suicide by other means. That is, the barrier appears to have had its intended impact at preventing suicide despite a short-term rise in deaths at other bridges that was at least partially influenced by a media effect. Research examining barriers at other locations should interpret short-term results with caution. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. 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)

  10. Identifying the Barriers to Women's Agency in Domestic Violence: The Tensions between Women's Personal Experiences and Systemic Responses

    Directory of Open Access Journals (Sweden)

    Jo Aldridge

    2013-04-01

    Full Text Available Despite advances in knowledge and understanding about the impacts of domestic violence on women's lives, global research on violence against women shows there is a need for research that not only places women centre stage in research praxis, but also that involves them more collaboratively in genuine dialogue about their experiences, including their agentic stances. This is especially the case for marginalised and socially excluded women victims of domestic violence, such as those who are not known or do not present to services and who survive abusive relationships alone or with little outside support. Evidence from two studies reported here—secondary analysis of women with severe and enduring mental health problems and a collaborative narrative project with unsupported women victims of domestic violence—suggest that women's capacity for agency are compromised by a number of critical factors, and that these are also reflected in the tensions between micro–macro analyses and understanding of the impact of domestic violence on women. This article considers the barriers to women's agency from the women's perspective and in the context of broader, systemic dynamics, including the denial or obscuring of abuse by governments and states and the consequences of stringent fiscal retrenchment that put women at increased risk of domestic violence.

  11. RESEARCH: Influence of Social, Biophysical, and Managerial Conditions on Tourism Experiences Within the Great Barrier Reef World Heritage Area.

    Science.gov (United States)

    Shafer; Inglis

    2000-07-01

    / Managing protected areas involves balancing the enjoyment of visitors with the protection of a variety of cultural and biophysical resources. Tourism pressures in the Great Barrier Reef World Heritage Area (GBRWHA) are creating concerns about how to strike this balance in a marine environment. Terrestrial-based research has led to conceptual planning and management frameworks that address issues of human use and resource protection. The limits of acceptable change (LAC) framework was used as a conceptual basis for a study of snorkeling at reef sites in the GBRWHA. The intent was to determine if different settings existed among tourism operators traveling to the reef and, if so, to identify specific conditions relating to those settings. Snorkelers (N = 1475) traveling with tourism operations of different sizes who traveled to different sites completed surveys. Results indicated that snorkelers who traveled with larger operations (more people and infrastructure) differed from those traveling with smaller operations (few people and little on-site infrastructure) on benefits received and in the way that specific conditions influenced their enjoyment. Benefits related to nature, escape, and family helped to define reef experiences. Conditions related to coral, fish, and operator staff had a positive influence on the enjoyment of most visitors but, number of people on the trip and site infrastructure may have the greatest potential as setting indicators. Data support the potential usefulness of visitor input in applying the LAC concept to a marine environment where tourism and recreational uses are rapidly changing.

  12. Analysis of thermal-hydrologic-mechanical behavior near an emplacement drift at Yucca Mountain

    International Nuclear Information System (INIS)

    Rutqvist, Jonny; Tsang, Chin-Fu

    2002-01-01

    A coupled thermal, hydrologic and mechanical (THM) analysis is conducted to evaluate the impact of coupled THM processes on the performance of a potential nuclear waste repository at Yucca Mountain, Nevada. The analysis considers changes in rock mass porosity, permeability, and capillary pressure caused by rock deformations during drift excavation, as well as those caused by thermo-mechanically induced rock deformations after emplacement of the heat-generating waste. The analysis consists of a detailed calibration of coupled hydraulic-mechanical rock mass properties against field experiments, followed by a prediction of the coupled thermal, hydrologic, and mechanical behavior around a potential repository drift. For the particular problem studied and parameters used, the analysis indicates that the stress-induced permeability changes will be within one order of magnitude and that these permeability changes do not significantly impact the overall flow pattern around the repository drift

  13. Remote excavation using the telerobotic small emplacement excavator

    International Nuclear Information System (INIS)

    Thompson, D.H.; Burks, B.L.; Killough, S.M.

    1993-01-01

    Oak Ridge National Laboratory is developing remote excavation technologies for the Office of Technology Development, Robotics Technology Development Program. This work is being done to meet the need for remote excavation and removal of radioactive and contaminated buried waste at several DOE sites. System requirements are based on the need to uncover and remove waste from burial sites in a way that does not cause unnecessary personnel exposure or additional environmental contamination. Goals for the current project are to demonstrate dexterous control of a backhoe with force feedback and to implement robotic operations that will improve productivity. The Telerobotic Small Emplacement Excavator is a prototype system that incorporates the needed robotic and telerobotic capabilities on a commercially available platform. The ability to add remote dexterous teleoperation and robotic operating modes is intended to be adaptable to other commercially available excavator systems

  14. Perceived Motivating Factors and Barriers for the Completion of Postgraduate Training Among American Pharmacy Students Prior to Beginning Advanced Pharmacy Practice Experiences.

    Science.gov (United States)

    Hammond, Drayton A; Oyler, Douglas R; Devlin, John W; Painter, Jacob T; Bolesta, Scott; Swanson, Joseph M; Bailey, Brett J; Branan, Trisha; Barletta, Jeffrey F; Dunn, Brianne; Haney, Jason S; Juang, Paul; Kane-Gill, Sandra L; Kiser, Tyree H; Shafeeq, Hira; Skaar, Debra; Smithburger, Pamela; Taylor, Jodi

    2017-06-01

    Objective. To examine perceived motivating factors and barriers (MFB) to postgraduate training (PGT) pursuit among pharmacy students. Methods. Third-year pharmacy students at 13 schools of pharmacy provided demographics and their plan and perceived MFBs for pursuing PGT. Responses were characterized using descriptive statistics. Kruskal-Wallis equality-of-proportions rank tests determined if differences in perceived MFBs existed between students based on plan to pursue PGT. Results. Among 1218 (69.5%) respondents, 37.1% planned to pursue PGT (32.9% did not, 30% were undecided). Students introduced to PGT prior to beginning pharmacy school more frequently planned to pursue PGT. More students who planned to pursue PGT had hospital work experience. The primary PGT rationale was, "I desire to gain more knowledge and experience." Student debt was the most commonly cited barrier. Conclusion. Introducing pharmacy students early to PGT options and establishing work experiences in the hospital setting may increase students' desire to pursue PGT.

  15. The emplacement of pahoehoe lavas on Kilauea and in the Deccan ...

    Indian Academy of Sciences (India)

    There is a growing interest in deciphering the emplacement and environmental impact of flood basalt provinces such as the Deccan, India. Observations of active volcanism lead to meaningful interpretations of now-extinct volcanic systems. Here, I illustrate and discuss the morphology and emplacement of the modern and ...

  16. Geomagnetic paleointensity in historical pyroclastic density currents: Testing the effects of emplacement temperature and postemplacement alteration

    Science.gov (United States)

    Bowles, Julie A.; Gee, Jeffrey S.; Jackson, Mike J.; Avery, Margaret S.

    2015-10-01

    Thellier-type paleointensity experiments were conducted on welded ash matrix or pumice from the 1912 Novarupta (NV) and 1980 Mt. St. Helens (MSH) pyroclastic density currents (PDCs) with the intention of evaluating their suitability for geomagnetic paleointensity studies. PDCs are common worldwide, but can have complicated thermal and alteration histories. We attempt to address the role that emplacement temperature and postemplacement hydrothermal alteration may play in nonideal paleointensity behavior of PDCs. Results demonstrate two types of nonideal behavior: unstable remanence in multidomain (MD) titanomagnetite, and nonideal behavior linked to fumarolic and vapor phase alteration. Emplacement temperature indirectly influences MSH results by controlling the fraction of homogenous MD versus oxyexsolved pseudo-single domain titanomagnetite. NV samples are more directly influenced by vapor phase alteration. The majority of NV samples show distinct two-slope behavior in the natural remanent magnetization—partial thermal remanent magnetization plots. We interpret this to arise from a (thermo)chemical remanent magnetization associated with vapor phase alteration, and samples with high water content (>0.75% loss on ignition) generate paleointensities that deviate most strongly from the true value. We find that PDCs can be productively used for paleointensity, but that—as with all paleointensity studies—care should be taken in identifying potential postemplacement alteration below the Curie temperature, and that large, welded flows may be more alteration-prone. One advantage in using PDCs is that they typically have greater areal (spatial) exposure than a basalt flow, allowing for more extensive sampling and better assessment of errors and uncertainty.

  17. Granite ascent and emplacement during contractional deformation in convergent orogens

    Science.gov (United States)

    Brown, Michael; Solar, Gary S.

    1998-09-01

    Based on a case study in the Central Maine Belt of west-central Maine, U.S.A., it is proposed that crustal-scale shear zone systems provide an effective focussing mechanism for transfer of granite melt through the crust in convergent orogens. During contractional deformation, flow of melt in crustal materials at depths below the brittle-plastic transition is coupled with plastic deformation of these materials. The flow is driven by pressure gradients generated by buoyancy forces and tectonic stresses. Within the oblique-reverse Central Maine Belt shear zone system, stromatic migmatite and concordant to weakly discordant irregular granite sheets occur in zones of higher strain, which suggests percolative flow of melt to form the migmatite leucosomes and viscous flow of melt channelized in sheet-like bodies, possibly along fractures. Cyclic fluctuations of melt pressure may cause instantaneous changes in the effective permeability of the flow network if self-propagating melt-filled tensile and/or dilatant shear fractures are produced due to melt-enhanced embrittlement. Inhomogeneous migmatite and schlieric granite occur in zones of lower strain, which suggests migration of partially-molten material through these zones en masse by granular flow, and channelized flow of melt carrying entrained residue. Founded on the Central Maine Belt case study, we develop a model of melt extraction and ascent using the driving forces, stress conditions and crustal rheologies in convergent, especially transpressive orogens. Ascent of melt becomes inhibited with decreasing depth as the solidus is approached. For intermediate a(H 2O) muscovite-dehydration melting, the water-saturated solidus occurs between 400 and 200 MPa, near the brittle-plastic transition during high- T-low- P metamorphism, where the balance of forces favors (sub-) horizontal fracture propagation. Emplacement of melt may be accommodated by ductile flow and/or stoping of wall rock, and inflation may be accommodated

  18. Laboratory experiment demonstrating the way in which a steam barrier prevents the dissolution of salt buried in a flooded packed bed

    International Nuclear Information System (INIS)

    Taylor, R.W.; Bowen, D.

    1977-01-01

    We have conducted a laboratory experiment to demonstrate a way in which a solid material can be prevented from dissolving in water. The differential solubility of salt (NaCl) in steam vs water is exploited. As long as the temperature of the area and water surrounding the salt is maintained above the boiling point of water, the salt cannot dissolve. This phenomenon, known as the thermal barrier, has far-reaching implications for preventing the dispersal of contaminants present near groundwater sources

  19. Emplacement of the Kodiak batholith and slab-window migration

    Science.gov (United States)

    Farris, David W.; Haeussler, P.; Friedman, R.; Paterson, Scott R.; Saltus, R.W.; Ayuso, R.

    2006-01-01

    The Kodiak batholith is one of the largest, most elongate intrusive bodies in the forearc Sanak-Baranof plutonic belt located in southern Alaska. This belt is interpreted to have formed during the subduction of an oceanic spreading center and the associated migration of a slab window. Individual plutons of the Kodiak batholith track the location and evolution of the underlying slab window. Six U/Pb zircon ages from the axis of the batholith exhibit a northeastward-decreasing age progression of 59.2 ± 0.2 Ma at the southwest end to 58.4 ± 0.2 Ma at the northeast tip. The trench-parallel rate of age progression is within error of the average slab-window migration rate for the entire Sanak-Baranof belt (~19 cm/yr). Structural relationships, U/Pb ages, and a model of new gravity data indicate that magma from the Kodiak batholith ascended 5-10 km as a northeastward-younging series of 1-8-km-diameter viscoelastic diapirs. Individual plutons ascended by multiple emplacement mechanisms including downward flow, collapse of wall rock, stoping, and diking. Stokes flow xenolith calculations suggest ascent rates of 5-100 m/yr and an effective magmatic viscosity of 107-108 Pa s. Pre-existing structural or lithologic heterogeneities did not dominantly control the location of the main batholith. Instead, its location was determined by migration of the slab window at depth. 

  20. Chemical barriers for controlling groundwater contamination

    International Nuclear Information System (INIS)

    Morrison, S.J.; Spangler, R.R.

    1993-01-01

    Chemical barriers are being explored as a low-cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts. 10 refs., 9 figs., 1 tab

  1. Graduate Student Placement: An Examination of Experience and Career Barriers in a Student Affairs Professional Preparation Program

    Directory of Open Access Journals (Sweden)

    Amy B Wilson

    2016-01-01

    Full Text Available This quantitative descriptive study examined the job placement success and challenges of graduate students in a higher education and student affairs professional preparation program at a mid-size public institution in the U.S. Specifically, this study investigated the impact of curricular standards in the form of supervised practice (i.e., internships and graduate assistantships on the job placement rate of recent alumni. In addition, perceived barriers in the job search process were investigated and examined comparatively by gender. Findings suggest that current curricular standards may not be sufficient for successful placement and that men and women do not differ significantly with respect to perceived barriers in their job search process. Implications for practice include a re-evaluation of curricular standards for student affairs professional preparation programs and a greater understanding of what factors and barriers contribute to successful graduate student placement.

  2. Managers' experience of success criteria and barriers to implementing mobile radiography services in nursing homes in Norway: a qualitative study.

    Science.gov (United States)

    Kjelle, Elin; Lysdahl, Kristin Bakke; Olerud, Hilde Merete; Myklebust, Aud Mette

    2018-04-25

    In order to meet the future challenges posed by ageing populations, new technology, telemedicine and a more personalized healthcare system are needed. Earlier research has shown mobile radiography services to be highly beneficial for nursing home residents in addition to being cost-effective. Despite the benefits, mobile radiography services are uncommon in Europe and Norway. The purpose of this study was to explore success criteria and barriers in the process of implementing mobile radiography services, from the point of view of the hospital and municipal managers. Eleven semi-structured interviews were conducted with managers from five hospitals and six municipalities in Norway where mobile radiography services had been implemented. Core issues in the interview guide were barriers and facilitators in the different phases of implementation. The framework method for thematic analysis was used for analysing the data inductively in a research team. Five main categories were developed through the success criteria and barriers experienced by the participants: national health policy, regional and municipal policy and conditions, inter-organizational implementation projects, experienced outcome, and professional skills and personal characteristics. The categories were allocated into three higher-order classifications: macro, meso and micro levels. The main barriers experienced by the managers were financial, procedural and structural. In particular, the reimbursement system, lack of management across healthcare levels and the lack of compatible information systems acted as barriers. The main facilitators were external funding, enthusiastic individuals in the organizations and good collaboration between hospitals and municipalities. The managers experienced financial, structural and procedural barriers. The main success criteria in the process were external funding, and the support and engagement from the individuals in the organizations. This commitment was mainly

  3. Experiences and barriers to Health-Related Quality of Life following liver transplantation: a qualitative analysis of the perspectives of pediatric patients and their parents

    Directory of Open Access Journals (Sweden)

    Taylor Rachel

    2010-12-01

    Full Text Available Abstract This paper examines health-related quality of life (HRQOL experiences and barriers facing young people who have received a liver transplant (LT. Semi-structured qualitative interviews were conducted with children and adolescents who have undergone LT and their parents. Findings indicate that LT fosters substantially improved child and adolescent HRQOL; however, young people also experience challenges such as difficulties with medication compliance, self-management of care routines, physical activity restrictions, and undesirable medical procedures. Implications and recommendations for clinical practice and research are discussed.

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

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

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

  5. Magma Emplacement Rates and Porphyry Copper Deposits: Thermal Modelling of the Yerington Batholith, Nevada, USA

    Science.gov (United States)

    Schöpa, Anne; Annen, Catherine; Dilles, John H.; Sparks, R. Stephen J.; Blundy, Jon D.

    2017-04-01

    Many porphyry copper deposits are associated with granitoid plutons. Their genesis is attributed to the degassing of pluton-forming intermediate to silicic magma chambers. These plutons are commonly envisioned as resulting from the slow cooling and crystallization of large magma chambers. Most of the models combine the formation of ore deposits and the cooling of a magma chamber. However, they do not consider neither how typically hundreds of cubic kilometres of magma were emplaced into the upper crust, nor the prolonged growth of plutons involving simultaneous cooling and crystallization together with the release of exsolved volatiles, which may contribute to ore formation. We use numerical simulations of thermal evolution due to pluton growth to investigate the links between pluton construction, magma accumulation, solidification, volatile exsolution, volatile release and porphyry copper formation. The Jurassic Yerington batholith in western Nevada, USA, is used as a case study because it is associated with economic porphyry copper deposits, it shows an exceptional exposure revealing the geometry of the intrusion, and petrological and geochronological analysis have shed light on its emplacement style and duration. Our conductive heat flow model simulates the growth of the ˜1000 km3 batholith emplaced at 2-8 km crustal depth by step-wise intrusions of vertically stacked sills. Different emplacement rates and repose times of no melt injection between the three main Yerington intrusions were tested. Our numerical simulations show that to comply with the conceptual model linking porphyry copper deposits with the presence of large, highly molten magma chambers, magmas must be emplaced at a high rate of several cm/yr. In plutonic records, such high rates are uncommon. It follows that either the current conceptual model is incorrect or that porphyry copper deposits are only produced by the rare, rapidly emplaced plutons. The fact that many granitoid plutons are barren

  6. Conceptual designs of automated systems for underground emplacement and retrieval of nuclear waste

    International Nuclear Information System (INIS)

    Slocum, A.H.; Hou, W.M.; Park, K.; Hochmuth, C.; Thurston, D.C.

    1987-01-01

    Current designs of underground nuclear waste repositories have not adequately addressed the possibility of automated, unmanned emplacement and retrieval. This report will present design methodologies for development of an automated system for underground emplacement of nuclear waste. By scaling generic issues to different repositories, it is shown that a two vehicle automated waste emplacement/retrieval system can be designed to operate in a fail-safe mode. Evaluation of cost at this time is not possible. Significant gains in worker safety, however, can be realized by minimizing the possibility of human exposure

  7. Emplacement of Fahrenheit crater ejecta at the Luna-24 site

    International Nuclear Information System (INIS)

    Settle, M.; Cintala, M.J.; Head, J.W.

    1979-01-01

    The Luna-24 site is situated in Mare Crisium at a range of 18.4 km from Fahrenheit, an Eratosthenian-aged crater 6.4 km in diameter. Fahrenheit's ejecta deposits have been degraded to such an extent that secondary craters and rays cannot be unambiguously identified in the vicinity of the Luna-24 site. On the basis of an analogy between Fahrenheit and Lichtenberg B (a much younger crater of comparable size located in northern Oceanus Procellarum) Fahrenheit ejecta deposits near the sample site are inferred to have consisted of secondary crater clusters, subradially aligned secondary crater chains, and lineated terrain furrowed by fine-scale radial grooves. At the range of the Luna-24 site more than 80% of the mare surface should have been morphologically disturbed by the ballistic deposition of Fahrenheit ejecta. Blocks and fragment clusters of primary Fehrenheit ejecta ranging up to 5-20 m in diameter are inferred to have impacted the local surface at velocities of 165-230 m s -1 forming secondary craters ranging up to 100m in diameter. The maximum depth of excavation of primary Fahrenheit ejecta deposited near the sample site is estimated to be at least 100m. Primary Fahremheit ejecta is expected to constitute a substantial fraction of the exterior deposits emplaced at the range of the Luna-24 site. Microgabbro and monomineralic fragments discovered in the Luna-24 drill core may have been derived from gabbroic rocks transported to the sample site by the Fahrenheit cratering event. This hypothesis is consistent with the widespread occurrence and characteristics of Fahrenheit ejecta anticipated in the vicinity of the Luna-24 site. (Auth.)

  8. Evidence for dike emplacement beneath Iliamna Volcano, Alaska in 1996

    Science.gov (United States)

    Roman, D.C.; Power, J.A.; Moran, S.C.; Cashman, K.V.; Doukas, M.P.; Neal, C.A.; Gerlach, T.M.

    2004-01-01

    Two earthquake swarms, comprising 88 and 2833 locatable events, occurred beneath Iliamna Volcano, Alaska, in May and August of 1996. Swarm earthquakes ranged in magnitude from -0.9 to 3.3. Increases in SO2 and CO2 emissions detected during the fall of 1996 were coincident with the second swarm. No other physical changes were observed in or around the volcano during this time period. No eruption occurred, and seismicity and measured gas emissions have remained at background levels since mid-1997. Earthquake hypocenters recorded during the swarms form a cluster in a previously aseismic volume of crust located to the south of Iliamna's summit at a depth of -1 to 4 km below sea level. This cluster is elongated to the NNW-SSE, parallel to the trend of the summit and southern vents at Iliamna and to the regional axis of maximum compressive stress determined through inversion of fault-plane solutions for regional earthquakes. Fault-plane solutions calculated for 24 swarm earthquakes located at the top of the new cluster suggest a heterogeneous stress field acting during the second swarm, characterized by normal faulting and strike-slip faulting with p-axes parallel to the axis of regional maximum compressive stress. The increase in earthquake rates, the appearance of a new seismic volume, and the elevated gas emissions at Iliamna Volcano indicate that new magma intruded beneath the volcano in 1996. The elongation of the 1996-1997 earthquake cluster parallel to the direction of regional maximum compressive stress and the accelerated occurrence of both normal and strike-slip faulting in a small volume of crust at the top of the new seismic volume may be explained by the emplacement and inflation of a subvertical planar dike beneath the summit of Iliamna and its southern satellite vents. ?? 2003 Elsevier B.V. All rights reserved.

  9. Transdomes: Emplacement of Migmatite Domes in Oblique Tectonic Settings

    Science.gov (United States)

    Teyssier, C. P.; Rey, P. F.; Whitney, D. L.; Mondy, L. S.; Roger, F.

    2014-12-01

    Many migmatite domes are emplaced within wrench corridors in which a combination of strike-slip and extensional detachment zones (pull-apart, extensional relay, or transfer zones) focus deep-crust exhumation. The Montagne Noire dome (France, Variscan Massif Central) exemplifies wrench-related dome formation and displays the following structural, metamorphic, and geochronologic characteristics of a 'transdome': the dome is elongate in the direction of extension; foliation outlines a double dome separated by a high-strain zone; lineation is shallowly plunging with a fairly uniform trend that parallels the strike of the high-strain zone; subdomes contain recumbent structures overprinted by upright folds that affected upward by flat shear zones associated with detachment tectonics; domes display a large syn-deformation metamorphic gradient from core (upper amphibolite facies migmatite) to margin (down to greenschist facies mylonite); some rocks in the dome core experienced isothermal decompression revealed by disequilibrium reaction textures, particularly in mafic rocks (including eclogite); and results of U-Pb geochrononology indicate a narrow range of metamorphic crystallization from core to mantling schist spanning ~10 Myr. 3D numerical modeling of transdomes show that the dome solicits a larger source region of partially molten lower crust compared to 2D models; this flowing crust creates a double-dome architecture as in 2D models but there are differences in the predicted thermal history and flow paths. In a transtension setting, flow lines converge at depth (radial-centripetal flow) toward the zone of extension and diverge at shallow levels in a more uniform direction that is imposed by upper crust motion and deformation. This evolution produces a characteristic pattern of strain history, progressive fabric overprint, and P-T paths that are comparable to observed dome rocks.

  10. Parameters and criteria influencing the selection of waste emplacement configurations in mined geologic repositories

    International Nuclear Information System (INIS)

    Bechthold, W.; Closs, K.D.; Papp, R.

    1988-01-01

    Reference concepts for repositories in deep geological formations have been developed in several countries. For these concepts, emplacement configurations vary within a wide range that comprises drift emplacement of unshielded or self-shielded packages and horizontal or vertical borehole emplacement. This is caused by different parameters, criteria, and criteria weighting factors. Examples for parameters are the country's nuclear power program and waste management policy, its geological situation, and safety requirements, examples for criteria and repository area requirements, expenditures of mining and drilling, and efforts for emplacement and, if required, retrieval. Due to the variety of these factors and their ranking in different countries, requirements for a safe, dependable and cost-effective disposal of radioactive waste can be met in various ways

  11. A qualitative exploration of participants' experiences of taking part in a walking programme: Perceived benefits, barriers, choices and use of intervention resources.

    Science.gov (United States)

    Mitchell, Fiona; Stalker, Kirsten; Matthews, Lynsay; Mutrie, Nanette; Melling, Chris; McConnachie, Alex; Murray, Heather; Melville, Craig A

    2018-01-01

    Adults with intellectual disabilities (ID) experience significant inequalities and tend to be more sedentary and less physically active than the wider population. Walking programmes are an effective way to increase physical activity (PA) but have not been used in studies involving adults with intellectual disabilities. Nineteen adults with intellectual disabilities participated in semistructured interviews or focus groups exploring their experiences of taking part in a walking programme (Walk Well). Data were coded using thematic analysis. Four overarching themes emerged: perceived benefits of taking part in the programme, perceived drawbacks/ barriers, walking choices and using the Walk Well resources. While there was not a significant increase in walking for all, the participants reported positive experiences of taking part in the programme. Self-monitoring proved difficult for some, particularly reading the daily step count recorded on the pedometer and writing it in the diary. Carers also played an important role in facilitating and preventing behaviour change in adults with intellectual disabilities. Additional barriers prevent many adults with intellectual disabilities from participating in PA. Capturing participant experiences provides important information for designing effective and equitable health improvement programmes. © 2016 John Wiley & Sons Ltd.

  12. The barriers and facilitators that indigenous health workers experience in their workplace and communities in providing self-management support: a multiple case study.

    Science.gov (United States)

    Conway, Jessica; Tsourtos, George; Lawn, Sharon

    2017-05-03

    The inequality in health outcomes between Indigenous (Throughout the paper, the term Indigenous will be used to represent both Aboriginal Australians and Torres Strait Islander Australians.) and non-Indigenous Australians continues to be a major public health issue. Chronic conditions are responsible for the majority of the gap in life expectancy for this population. Evidence suggests that chronic condition management models focusing on self-management have led to improved health outcomes in Indigenous populations. The Flinders Closing the Gap Program (FCTGP) is a chronic condition care planning tool which aims to engage Indigenous people in self-managing their chronic conditions. Indigenous health workers (IHWs) can provide culturally appropriate self-management support; however there is paucity in current literature describing specific barriers and facilitators that they may experience when attempting to deliver this support. This study aimed to explore IHWs' perceptions of the effectiveness and appropriateness of the FCTGP, as an evidence-based example of self-management support, and to explore the barriers and facilitators that IHWs experience in their workplace and communities in providing self-management support. In-depth interviews were undertaken with five IHWs, drawn from five different states in Australia. Their selection was aided by key informants from the FCTGP training unit. Interviews were recorded and transcribed verbatim, and were analysed using thematic analysis. The following themes were identified. IHWs reported that the FCTGP was appropriate, flexible and acceptable in their communities. Facilitators included factors improving client and worker empowerment, and activities around sharing knowledge. Barriers included competing priorities that clients experience relating to social determinants of health, and negative experiences within mainstream health services. IHW burnout from time pressures, lack of support, and high staff turnover were also

  13. Preliminary test on filling gap behavior of the swollen buffer in the engineered barrier system. 2

    International Nuclear Information System (INIS)

    Sugita, Yutaka; Tanai, Kenji

    2003-11-01

    In geological disposal of the high-level radioactive waste (HLW), the engineered barrier system (EBS) (buffer, waste packages (capsulate the vitrified waste)) is installed in the space of a repository using the remote control technique due to protect workers from radiation. The block type buffer, as one of the candidate options of the installation of the buffer, has the gap between buffer and rock or waste package. In this case, the highly compacted buffer will be used to fill the gap by the swollen buffer. Swelling of the buffer is considered to begin from the surface of the buffer where groundwater infiltrates. Infiltration of groundwater into the buffer is considered to be 3 dimensional, because the gap and the infiltration points of the buffer are distributed spatially. Therefore, non-uniformity of the swelling of the buffer will affect the thickness of the buffer between waste package and rock mass. Long term experiments of preliminary tests that simulate 3 dimensional filling gap behavior of the swollen buffer were performed. Other test simulates the vertical emplacement option was performed, too. The test results showed that as follows; In Horizontal emplacement option, swelling of the buffer began from the surface of the buffer. Swollen buffer infiltrated into gap region there is no stress against infiltration of the buffer. Distribution of the density of the buffer was changed with time. In vertical emplacement option, there is scatter of the density of the buffer also. In center region which has the buffer initial, density was still high. Near the surface of test cell, density of the buffer was low. In this case, since the buffer was installed at the center of the test cell, density of the buffer was uniform in a circumference section. In case of swelling of the buffer with the gap, initial condition, swelling behavior and change of the density after filled the gap of the buffer should be observed. (author)

  14. Subsurface barrier validation with the SEAtrace{trademark} system

    Energy Technology Data Exchange (ETDEWEB)

    Sandra Dalvit Dunn; William Lowry; Veraun Chipman

    1999-09-01

    Under contract to the Department of Energy, Science and Engineering Associates has completed development and testing of a subsurface barrier verification and monitoring system. This system, called SEAtrace{trademark}, is able to locate and size leaks with a high degree of accuracy in subsurface barriers that are emplaced in an unsaturated medium. It uses gaseous tracer injection, in-field real-time monitoring, and real time data analysis to evaluate barrier integrity. The approach is: Conservative as it measures vapor leaks in a containment system whose greatest risk is posed by liquid leaks; Applicable to any impermeable type of barrier emplacement technology in the unsaturated zone; Inexpensive as it uses readily available, non-toxic, nonhazardous gaseous tracers, does not require an inordinately large number of sampling points, and injection and sampling points can be emplaced by direct push techniques; Capable of assessing not only a barrier's initial integrity, but can also provide long-term monitoring. To date, six demonstrations of the system have been completed. Results from two of the demonstrations are detailed in this report. They include the final developmental demonstration of the SEAtrace system and a comparison demonstration of two tracer based verification technologies. The final developmental demonstration of SEAtrace was completed at a naval facility in Brunswick, Maine. The demonstration was funded solely by the DOE and was performed in cooperation with the US Navy, the Environmental Protection Agency, and the Maine Department of Environmental Protection.

  15. Tracking health care service use and the experiences of adults with autism spectrum disorder without intellectual disability: A longitudinal study of service rates, barriers and satisfaction.

    Science.gov (United States)

    Vogan, Vanessa; Lake, Johanna K; Tint, Ami; Weiss, Jonathan A; Lunsky, Yona

    2017-04-01

    Adults with Autism Spectrum Disorder (ASD) encounter many difficulties finding and accessing health care services. Despite this, few studies have considered the health service use patterns of adults with ASD without intellectual disability (ID). The current study examines a diverse range of medical and mental health services and supports, as well as adults' personal experiences accessing and using these services, barriers to service use, and reported unmet service needs. Forty adults (ages 18-61 years) with ASD without ID completed surveys every two months about their health service use for a total of 12-18 months. Bivariate analyses were conducted to understand the individual demographic and clinical factors associated with rate of service use, satisfaction with services, and barriers to health care. Results indicated that, beyond a family doctor, the most commonly used services were dentistry, individual counseling, and psychiatry. Individuals who had medical problems experienced significantly more barriers to service use than those who did not, and those who had medical and mental health problems were less satisfied with services. Findings highlight the challenges adults with ASD without ID face accessing appropriate, quality services to meet their needs, particularly those with complex medical and mental health issues. Service providers must strive to provide adequate health care to this population who may become distressed if their needs are left unmet. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Seeking sexual health information? Professionals' novel experiences of the barriers that prevent female adolescents seeking sexual health information.

    Science.gov (United States)

    McKellar, Kerry; Little, Linda; Smith, Michael A; Sillence, Elizabeth

    2017-07-21

    Objective Sexual health professionals are key stakeholders in implementing sexual health intervention programmes, yet their views are largely absent from the literature. Sexual health professionals provide a unique perspective on teen sexual health issues as they engage in confidential discussions with a wide range of teenagers. This study aimed to provide an in-depth exploration of professionals' perceptions of teenagers' sexual health information seeking practices and barriers. Furthermore, the research provided a unique re-examination of key predictors of risky sexual behaviours, which have been highlighted by previous research. Methods Nine semi-structured interviews were undertaken with sexual health professionals to explore their perceptions of teenagers' sexual health information seeking practises and barriers. Subsequently the professionals rank ordered the 57 factors identified in previous research in terms of their perceived importance in predicting risky sexual behaviours. Results Four themes emerged: "society and media"; "environment and family"; "peer influences"; and "the self". The rank order task confirmed that 33 of the 57 factors were perceived as highly important by sexual health professionals. Conclusion Society, peers, environment and family are perceived as barriers to teenagers seeking reliable sexual health information, but these are dependent on the individual person. An individual with higher self-esteem is more confident in seeking sexual health information and applying this knowledge appropriately. Self-esteem was also identified as a key perceived predictor of risky sexual behaviours. Therefore, there is scope for intervention programmes targeting self-esteem and knowledge, so teenagers have the confidence to seek out sexual health information and to make their own informed sexual health decisions.

  17. Key stakeholder perspectives on the barriers and solutions to pharmacy practice towards complementary medicines: an Australian experience.

    Science.gov (United States)

    Ung, Carolina Oi Lam; Harnett, Joanna; Hu, Hao

    2017-08-09

    Although pharmacists are entrusted to play a role in ensuring the safe and appropriate use of all medicines, in general, the inclusion of complementary medicines (CMs) into their professional practice has not been observed. The purpose of this study was to explore the perceptions and opinions of pharmacists and 8 key stakeholder leaders regarding the barriers that hinder pharmacists from providing care related to the use of CMs by patients/consumers and to identify solutions that would support pharmacists' in extending their role in this area. Semi-structured key informant interviews were conducted with 2 practicing pharmacists, 1 pharmacy owner, 1 key representative of a pharmacist professional organization, 1 key representative of a consumer advocacy group, 1 key representative of a medical professional organization, 1 key representative from a complementary medicine practitioner professional organization, 1 leader within a pharmacy school, 2 senior staff from a regulatory authority, and 1 key representative of the complementary medicine industry in Australia. A total of 9 barriers were identified in this study. Barriers including a lack of CMs knowledge, doubts about the evidence-base, a lack of research skills and access to reliable and reputable information dominated the discussions. A total of 7 solutions were proposed. Of those, the integration of CMs curricula into under-graduate and professional pharmacy education, and defining a clearer role for pharmacists' standard of practice were considered the most important. Apposing opinions about the role of naturopaths in pharmacies were identified.. It is anticipated that pharmacists will be required to formalise a role in ensuring the safe and appropriate use of complementary medicines to fulfil their professional and ethical responsibilities. However, pharmacists in general are not ready to take up this extended role. Individual key stakeholder groups have considered the existing barriers and have proposed

  18. Conodont geothermometry in pyroclastic kimberlite: constraints on emplacement temperatures and cooling histories

    Science.gov (United States)

    Pell, Jennifer; Russell, James K.; Zhang, Shunxin

    2018-03-01

    Kimberlite pipes from Chidliak, Baffin Island, Nunavut, Canada host surface-derived Paleozoic carbonate xenoliths containing conodonts. Conodonts are phosphatic marine microfossils that experience progressive, cumulative and irreversible colour changes upon heating that are experimentally calibrated as a conodont colour alteration index (CAI). CAI values permit us to estimate the temperatures to which conodont-bearing rocks have been heated. Conodonts have been recovered from 118 samples from 89 carbonate xenoliths collected from 12 of the pipes and CAI values within individual carbonate xenoliths show four types of CAI distributions: (1) CAI values that are uniform throughout the xenolith; (2) lower CAIs in core of a xenolith than the rim; (3) CAIs that increase from one side of the xenolith to the other; and, (4) in one xenolith, higher CAIs in the xenolith core than at the rim. We have used thermal models for post-emplacement conductive cooling of kimberlite pipes and synchronous heating of conodont-bearing xenoliths to establish the temperature-time history of individual xenoliths within the kimberlite bodies. Model results suggest that the time-spans for xenoliths to reach the peak temperatures recorded by CAIs varies from hours for the smallest xenoliths to 2 or 3 years for the largest xenoliths. The thermal modelling shows the first three CAI patterns to be consistent with in situ conductive heating of the xenoliths coupled to the cooling host kimberlite. The fourth pattern remains an anomaly.

  19. Three integrated photovoltaic/sound barrier power plants. Construction and operational experience; Drei integrierte PV-Schallschutz Versuchsfelder. Bau und Erprobung

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-01

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

  20. Engineered Barrier System: Physical and Chemical Environment

    International Nuclear Information System (INIS)

    Dixon, P.

    2004-01-01

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

  1. Building barriers.

    Science.gov (United States)

    Turksen, Kursad

    2017-10-02

    Formation of tissue barriers starts in early development where it is critical for normal cell fate selection, differentiation and organogenesis. Barrier maintenance is critical to the ongoing function of organs during adulthood and aging. Dysfunctional tissue barrier formation and function at any stage of the organismal life cycle underlies many disease states.

  2. Seeking help for obsessive compulsive disorder (OCD): a qualitative study of the enablers and barriers conducted by a researcher with personal experience of OCD.

    Science.gov (United States)

    Robinson, Karen J; Rose, Diana; Salkovskis, Paul M

    2017-06-01

    Obsessive compulsive disorder (OCD) can be hugely disabling. Although very effective psychological treatments exist, many people delay years before seeking help or never seek treatment. There have been clinical observation and short questionnaire studies on why people delay, but little qualitative research exists on this complex subject. The present qualitative study aimed to identify the barriers to seeking treatment and the factors that encourage or push people to seek help for their OCD (positive and negative enablers). A qualitative, exploratory study using in-depth, individual, semi-structured interviews was conducted by a researcher with personal experience of OCD. Seventeen people with OCD, contacted through the charity OCD-UK, were interviewed about the factors that impacted on their decision to seek help or not. The interviews were analysed using thematic analysis. Barriers identified were stigma, 'internal / cognitive' factors, not knowing what their problem was, factors relating to their GP or treatment, and fear of criminalisation. Positive enablers identified were being supported to seek help, information and personal accounts of OCD in the media, and confidence in their GP. Negative enablers were reaching a crisis point and for some participants (whose intrusive thoughts were about harming children) feeling driven to seek treatment because of the nature of the thoughts, that is, seeking help to prevent the 'harm' they feared they were capable of doing. Participants identified a range of barriers and enablers that impacted on their decision to seek help or not. These give important indicators about the likely causes for delayed help seeking in OCD and ways in which people might be encouraged to seek help earlier. People with OCD may face a wide range of barriers to seeking help, including concern about the reaction of health professionals. The level of awareness, kindness, and understanding shown by first-line practitioners can be very important to

  3. An Examination of Pre-Service Agricultural Science Teachers' Interest and Participation in International Experiences: Motivations and Barriers

    Science.gov (United States)

    Murphrey, Theresa Pesl; Lane, Katy; Harlin, Julie; Cherry, Audie

    2016-01-01

    The importance of creating global mindedness within pre-service agricultural science teachers through international experiences cannot be overstated. However, providing opportunities for international experiences and college students selecting to participate in these opportunities are two very different actions. Mechanisms must be put in place…

  4. 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)

  5. Emplacement of ultramafic-carbonatite intrusions along reactivated North American mid-continent rift structures

    Science.gov (United States)

    Shavers, Ethan J.; Ghulam, Abduwasit; Encarnacion, John; Hartling, Sean

    2017-08-01

    Understanding the various emplacement pathways of ultramafic‑carbonatite intrusive complexes and mapping of their global distribution are in an early stage. Discerning the pattern of their emplacement can reveal information about earth's dynamics and guide exploration for associated economic deposits. Here we apply multiple spatial analysis methods and synthetic aperture radar (SAR) data to assess the correlation between outcrops of ultramafic‑carbonatite intrusives and regional craton-scale fractures and assign targets for further exploration. Kernel density cluster, two-point azimuth, and the Fry method two-dimension spatial analyses are applied to 58 known outcrops of intrusives in the Avon Volcanic District (AVD), southeast Missouri USA. The results of the spatial analysis show linear trends among the outcrops with three primary orientations: northwest, northeast, and east-west and a strong correlation with regional fault zones. SAR data processing and analysis guided by the spatial results reveals rhombic lineament patterns with sides that parallel the northwest-northeast emplacement patterns of the AVD. These rhombic structures are related to possible extensional stepover duplexes, likely formed during Precambrian North American plate rifting along transfer faults. Reactivation of the Precambrian structures during high angle dip slip and wrench faulting that was penecontemporaneous with emplacement of the AVD in the Devonian likely provided pathways for the mantle-derived intrusives. These findings can guide exploration efforts and help us understand the emplacement of a unique intracontinental intrusive complex.

  6. Heat transfer effects in vertically emplaced high level nuclear waste container

    International Nuclear Information System (INIS)

    Moujaes, S.F.; Lei, Y.M.

    1994-01-01

    Modeling free convection heat transfer in a cylindrical annular enclosure is still an active area of research and an important problem to be addressed in the high level nuclear waste repository. For the vertically emplaced waste container, the air gap which is between the container shell and the rock borehole, have an important role of dissipating heat to surrounding rock. These waste containers are vertically emplaced in the borehole 300 meters just below ground, and in a horizontal grid of 30 x 8 meters apart. The borehole will be capped after the container emplacement. The expected initial heat generated is between 3-4.74 kW per container depending on the type of waste. The goal of this study is to use a computer simulation model to find the borehole wall, air-gap and the container outer wall temperature distributions. The borehole wall temperature history has been found in the previous study, and was estimated to reach a maximum temperature of about 218 degrees C after 18 years from the emplacement. The temperature history of the rock surface is then used for the air-gap simulation. The problem includes convection and radiation heat transfer in a vertical enclosure. This paper will present the results of the convection in the air-gap over one thousand years after the containers' emplacement. During this long simulation period it was also observed that a multi-cellular air flow pattern can be generated in the air gap

  7. Equipment for the emplacement of heat-producing waste in long horizontal boreholes

    International Nuclear Information System (INIS)

    Young, K.D.; Scully, L.W.; Fisk, A.; deBakker, P.; Friant, J.; Anderson, A.

    1983-01-01

    Emplacement of heat-producing waste in long horizontal holes may offer several technical and economic advantages over shallow vertical hole emplacement. Less of the host rock suffers damage as a result of drift construction; the heat from the waste can be isolated from the access drifts for long periods of time; and the amount of rock which must be excavated is much less than in traditional disposal scenarios. One of the major reasons that has been used to reject the long hole concept in the past and adhere to the shallow vertical hole concept is the equipment required to drill the holes and to emplace and retrieve the waste. Such equipment does not currently exist. It clearly is more difficult to drill a 600 to 1000 foot horizontal hole, possibly 3 to 4 feet in diameter, and place a canister of waste at the end of it than to drill a 30 foot vertical hole and lower the waste to the bottom. A liner, for emplacement hole stabilization, appears to be feasible by adapting existing technology for concrete slip forming or jacking in a steel liner. The conceptual design of the equipment to drill long horizontal holes, emplace waste and retrieve waste will be discussed. Various options in concept will be presented as well as their advantages and disadvantages. The operating scenario of the selected concept will be described as well as solutions to potential problems encountered

  8. Ethnic and Social Barriers to Cooperation: Experiments Studying the Extent and Nature of Discrimination in Urban Peru

    OpenAIRE

    Marco Castillo; Ragan Petrie; Máximo Torero

    2008-01-01

    This paper presents a series of experiments on discrimination in urban Lima, Peru. The experiments exploit degrees of information on performance as a way to assess how personal characteristics affect how people sort into groups, and the results show that behavior is not correlated with personal socio-economic and racial characteristics. However, people do use personal characteristics to sort themselves into groups. Height is a robust predictor of being desirable, as is being a woman. Looking ...

  9. Emplacement feasibility of a multi-tier, expanded capacity repository at Yucca Mountain, Nevada USA

    International Nuclear Information System (INIS)

    Apted, Michael; Kessler, John; Fairhurst, Charles

    2008-01-01

    / mining practices. (ii) Radiation Hazards: T he presence of the waste-filled drifts 30 m above or below other drifts might cause elevated radiation exposures to workers during drift excavation and subsequent operations. It is well established that a 1-m or so cylinder of concrete, as used in dry cask surface storage at nuclear facilities, is sufficient to reduce radiation emanating from the concrete to safe levels. Radiation intensity declines exponentially with thickness of the 'container'. Thus, radiation levels in the adjacent tunnels will be negligible. (iii) Thermal effects: The natural rock temperature at Yucca Mountain is 24 deg C. Analysis indicates that heat generated by radioactive decay of the waste-filled drifts will cause a maximum temperature increase of <60 deg C above ambient (i.e., 84 deg C) at a radial distance of 30 m from the filled drift. Calculations indicate that the readily achievable removal of 75 watts /m of drift length is sufficient to bring the temperature in the drift to ambient 24oC. Removal of heat generated during the rock excavation process by tunnel boring machine (TBM), a more severe challenge, has been proven in deep mines in South Africa. The ventilation requirements to drive supplementary drifts at 30-m from a waste-filled drift and maintain a 24 deg C drift environment will be no different from the requirements when driving waste emplacement drifts already excavated. (iv) Thermo-mechanical effects: Increase in the rock temperature due to heat generated in the waste-filled drifts will produce thermal stresses in the rock that will be superimposed on the pre-existing rock stresses. The increased stresses will decline in proportion to the square of the distance, expressed as a ratio of the drift radius (2.75 m), from the heated drift. For example, at 25 m (i.e. 9 radii) spacing, the increase in stress at the supplementary tunnels will be (1/9)2 or approximately 1%. Based on existing engineering practice and experience, it is concluded

  10. Investigating lava-substrate interactions through flow experiments with syrup, wax, and molten basalt

    Science.gov (United States)

    Rumpf, M. E.; Lev, E.

    2015-12-01

    Among the many factors influencing the complex process of lava flow emplacement, the interaction with the substrate onto which flow is emplaced plays a central role. Lava flows are rarely emplaced onto smooth or regular surfaces. For example, at Kīlauea Volcano, Hawai'i, lava flows regularly flow over solid rock, vegetation, basaltic or silica sand, and man-made materials, including asphalt and concrete. In situ studies of lava-substrate interactions are inherently difficult, and often dangerous, to carry-out, requiring the design of controllable laboratory experiments. We investigate the effects of substrate grain size, cohesion, and roughness on flow mobility and morphology through a series of flow experiments using analog materials and molten basalt. We have developed a series of experiments that allow for adjustable substrate parameters and analyze their effects on lava flow emplacement. The first set of experiments are performed at the Fluids Mechanics Laboratory at the Lamont-Doherty Earth Observatory and focus on two analog materials: polyethylene glycol (PEG), a commercially available wax, and corn syrup. The fluids were each extruded onto a series of scaled substrate beds to replicate the emplacement of lava in a natural environment. Preliminary experiments demonstrated that irregular topography, particularly topography with a height amplitude similar to that of the flow itself, can affect flow morphology, width, and velocity by acting as local barriers or culverts to the fluid. This is expected from observations of fluid flow in natural environments. A follow-up set of experiments will be conducted in Fall 2015 at the Syracuse University (SU) Lava Project Lab. In this set, we will pour molten basalt directly onto a series of substrates representing natural environments found on the Earth and other rocky bodies in the Solar System. These experiments will allow for analysis of the effects of basaltic composition and high temperatures on lava-substrate heat

  11. Heat transfer effects in vertically emplaced high level nuclear waste container

    International Nuclear Information System (INIS)

    Moujaes, S.F.; Lei, Y.M.

    1994-01-01

    Modeling free convection heat transfer in an cylindrical annular enclosure is still an active area of research and an important problem to be addressed in the high level nuclear waste repository. For the vertically emplaced waste container, the air gap which is between the container shell and the rock borehole, have an important role of dissipating heat to surrounding rack. These waste containers are vertically emplaced in the borehole 300 meters below ground, and in a horizontal grid of 30 x 8 meters apart. The borehole will be capped after the container emplacement. The expected initial heat generated is between 3--4.74 kW per container depending on the type of waste. The goal of this study is to use a computer simulation model to find the borehole wall, air-gap and the container outer wall temperature distributions

  12. Waste Handling and Emplacement Options for Disposal of Radioactive Waste in Deep Boreholes.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John R.; Hardin, Ernest

    2015-11-01

    Traditional methods cannot be used to handle and emplace radioactive wastes in boreholes up to 16,400 feet (5 km) deep for disposal. This paper describes three systems that can be used for handling and emplacing waste packages in deep borehole: (1) a 2011 reference design that is based on a previous study by Woodward–Clyde in 1983 in which waste packages are assembled into “strings” and lowered using drill pipe; (2) an updated version of the 2011 reference design; and (3) a new concept in which individual waste packages would be lowered to depth using a wireline. Emplacement on coiled tubing was also considered, but not developed in detail. The systems described here are currently designed for U.S. Department of Energy-owned high-level waste (HLW) including the Cesium- 137/Strontium-90 capsules from the Hanford Facility and bulk granular HLW from fuel processing in Idaho.

  13. Waste Handling and Emplacement Options for Disposal of Radioactive Waste in Deep Boreholes

    International Nuclear Information System (INIS)

    Cochran, John R.; Hardin, Ernest

    2015-01-01

    Traditional methods cannot be used to handle and emplace radioactive wastes in boreholes up to 16,400 feet (5 km) deep for disposal. This paper describes three systems that can be used for handling and emplacing waste packages in deep borehole: (1) a 2011 reference design that is based on a previous study by Woodward-Clyde in 1983 in which waste packages are assembled into ''strings'' and lowered using drill pipe; (2) an updated version of the 2011 reference design; and (3) a new concept in which individual waste packages would be lowered to depth using a wireline. Emplacement on coiled tubing was also considered, but not developed in detail. The systems described here are currently designed for U.S. Department of Energy-owned high-level waste (HLW) including the Cesium- 137/Strontium-90 capsules from the Hanford Facility and bulk granular HLW from fuel processing in Idaho.

  14. Identification of alkaptonuria in the general population: a United Kingdom experience describing the challenges, possible solutions and persistent barriers.

    Science.gov (United States)

    Ranganath, L; Taylor, A M; Shenkin, A; Fraser, W D; Jarvis, J; Gallagher, J A; Sireau, N

    2011-06-01

    Progress in research into rare diseases is challenging. This paper discusses strategies to identify individuals with the rare genetic disease alkaptonuria (AKU) within the general population. Strategies used included a questionnaire survey of general practitioners, a dedicated website and patient network contact, targeted family screening and medical conference targeting. Primary care physicians of the UK were targeted by a postal survey that involved mailing 11,151 UK GPs; the response rate was 18.2%. We have identified 75 patients in the UK with AKU by the following means: postal survey (23), targeted family screening (11), patient networks and the website (41). Targeting medical conferences (AKU, rare diseases, rheumatology, clinical biochemistry, orthopaedics, general practitioners) did not lead to new identification in the UK but helped identify overseas cases. We are now aware of 626 patients worldwide including newly identified non-UK people with AKU in the following areas: Slovakia (208), the rest of Europe (including Turkey) (79), North America (including USA and Canada) (110), and the rest of the world (154). A mechanism for identifying individuals with AKU in the general population-not just in the UK but worldwide-has been established. Knowledge of patients with AKU, both in the UK and outside, is often confined to establishing their location in a particular GP practice or association with a particular medical professional. Mere identification, however, does not always lead to full engagement for epidemiological research purposes or targeting treatment since further barriers exist.

  15. Ash production through brittle cataclasis during dome emplacement

    Science.gov (United States)

    Kennedy, Lori; Russell, Kelly

    2010-05-01

    Fine-grained gouge (Mount Saint Helens. Here, we present grain size data from both the natural fault rocks from Mount Saint Helen's and experimentally generated gouge. Our triaxial rock deformation experiments were run at confining pressures (Pc) of 0, 25, 50, and 75MPa, at room temperature and strain rates of ~1 x 10-4/s. We performed experiments that were terminated after failure and experiments on frictional sliding of the gouge. Our starting material has low (6-8%) porosities, a uniform bulk composition (65 wt% SiO2) and is highly. The dacite experiments show a progressive increase in peak strength (100-700 MPa) with increasing Pc and all cores show brittle behavior, characterized by a rapid stress drop. Run products contain macroscopic fractures with deformation extremely localized around the shear fractures. Experimentally deformed dacites show extreme grain size reduction and the production of gouge. Gouge material can reach < 1 micron in diameter. Frictional sliding experiments generated more gouge than experiments stopped after failure. However, there is little modification of the finest grain sizes (<20 microns) because of frictional sliding. We propose that the large stress drop at failure generates the fine-grained gouge and subsequent sliding does not further reduce the grain size. The amount of energy required to produce the fine-grained material is calculated and we compare this to the energy required to generate volcanic ash from fragmentation.

  16. A narrative review of acute care nurses' experiences nursing patients with intellectual disability: underprepared, communication barriers and ambiguity about the role of caregivers.

    Science.gov (United States)

    Lewis, Peter; Gaffney, Ryan J; Wilson, Nathan J

    2017-06-01

    To describe how nurses experience caring for people with intellectual disability in an acute care setting. Recent advances in the care of people with intellectual disability in hospital are primarily based upon the experiences of people with intellectual disability and their caregivers. Little is known about the experiences of registered nurses caring for people with intellectual disability, yet the experiences of nurses in delivering care largely determine the quality of care experienced by people with intellectual disability and their caregivers. A narrative literature review using electronic database searches was conducted using variants of the terms disability, nursing and acute care. Through our reading of the recent literature describing the experiences of nurses caring for people with intellectual disability in an acute care setting, we have identified three themes: (1) nurses feel underprepared when caring for patients with intellectual disability, (2) nurses experience challenges when communicating with people with intellectual disability and (3) nurses have ambiguous expectations of paid and unpaid caregivers. The enablers of and barriers to the delivery of nursing care in acute care settings need to be made explicit and researchers and nurses need to collaborate in the development, implementation and evaluation of care delivery strategies. Nurses need to be adequately prepared to care for people with intellectual disability. Preparation should include dealing with the complexities of communicating with people with intellectual disability and practical experience of doing so in clinical and educational environments that ensure the safety and dignity of nurses and people with intellectual disability. Nurses need supportive strategies for developing therapeutic relationships with a range of informal and formal caregivers. © 2016 The Authors. Journal of Clinical Nursing Published by John Wiley & Sons Ltd.

  17. Eruption and emplacement dynamics of a thick trachytic lava flow of the Sancy volcano (France)

    Science.gov (United States)

    Latutrie, Benjamin; Harris, Andrew; Médard, Etienne; Gurioli, Lucia

    2017-01-01

    A 70-m-thick, 2200-m-long (51 × 106 m3) trachytic lava flow unit underlies the Puy de Cliergue (Mt. Dore, France). Excellent exposure along a 400-m-long and 60- to 85-m-high section allows the flow interior to be accessed on two sides of a glacial valley that cuts through the unit. We completed an integrated morphological, structural, textural, and chemical analysis of the unit to gain insights into eruption and flow processes during emplacement of this thick silicic lava flow, so as to elucidate the chamber and flow dynamic processed that operate during the emplacement of such systems. The unit is characterized by an inverse chemical stratification, where there is primitive lava beneath the evolved lava. The interior is plug dominated with a thin basal shear zone overlying a thick basal breccia, with ramping affecting the entire flow thickness. To understand these characteristics, we propose an eruption model that first involves processes operating in the magma chamber whereby a primitive melt is injected into an evolved magma to create a mixed zone at the chamber base. The eruption triggered by this event first emplaced a trachytic dome, into which banded lava from the chamber base was injected. Subsequent endogenous dome growth led to flow down the shallow slope to the east on which the highly viscous (1012 Pa s) coulée was emplaced. The flow likely moved extremely slowly, being emplaced over a period of 4-10 years in a glacial manner, where a thick (>60-m) plug slid over a thin (5-m-thick) basal shear zone. Excellent exposure means that the Puy de Cliergue complex can be viewed as a case type location for understanding and defining the eruption and emplacement of thick, high-viscosity, silicic lava flow systems.

  18. Previous experiences and emotional baggage as barriers to lifestyle change - a qualitative study of Norwegian Healthy Life Centre participants.

    Science.gov (United States)

    Følling, Ingrid S; Solbjør, Marit; Helvik, Anne-S

    2015-06-23

    Changing lifestyle is challenging and difficult. The Norwegian Directorate of Health recommends that all municipalities establish Healthy Life Centres targeted to people with lifestyle issues. Little is known about the background, experiences and reflections of participants. More information is needed about participants to shape effective lifestyle interventions with lasting effect. This study explores how participants in a lifestyle intervention programme describe previous life experiences in relation to changing lifestyle. Semi-structured qualitative in-depth interviews were performed with 23 participants (16 women and 7 men) aged 18 - 70 years. The data were analysed using systematic text condensation searching for issues describing participants' responses, and looking for the essence, aiming to share the basis of life-world experiences as valid knowledge. Participants identified two main themes: being stuck in old habits, and being burdened with emotional baggage from their previous negative experiences. Participants expressed a wish to change their lifestyles, but were unable to act in accordance with the health knowledge they possessed. Previous experiences with lifestyle change kept them from initiating attempts without professional assistance. Participants also described being burdened by an emotional baggage with problems from childhood and/or with family, work and social life issues. Respondents said that they felt that emotional baggage was an important explanation for why they were stuck in old habits and that conversely, being stuck in old habits added load to their already emotional baggage and made it heavier. Behavioural change can be hard to perform as psychological distress from life baggage can influence the ability to change. The study participants' experience of being stuck in old habits and having substantial emotional baggage raises questions as to whether or not Healthy Life Centres are able to help participants who need to make a lifestyle

  19. Persistent barriers to care; a qualitative study to understand women's experiences in areas served by the midwives service scheme in Nigeria.

    Science.gov (United States)

    Exley, Josephine; Pitchforth, Emma; Okeke, Edward; Glick, Peter; Abubakar, Isa Sadeeq; Chari, Amalavoyal; Bashir, Usman; Gu, Kun; Onwujekwe, Obinna

    2016-08-19

    The Nigerian Midwives Service Scheme (MSS) is an ambitious human resources project created in 2009 to address supply side barriers to accessing care. Key features include the recruitment and deployment of newly qualified, unemployed and retired midwives to rural primary healthcare centres (PHCs) to ensure improved access to skilled care. This study aimed to understand, from multiple perspectives, the views and experiences of childbearing women living in areas where it has been implemented. A qualitative study was undertaken as part of an impact evaluation of the MSS in three states from three geo-political regions of Nigeria. Semi-structured interviews were conducted around nine MSS PHCs with women who had given birth in the past six months, midwives working in the PHCs and policy makers. Focus group discussions were held with wider community members. Coding and analysis of the data was performed in NVivo10 based on the constant comparative approach. The majority of participants reported that there had been positive improvements in maternity care as a result of an increasing number of midwives. However, despite improvements in the perceived quality of care and an apparent willingness to give birth in a PHC, more women gave birth at home than intended. There were some notable differences between states, with a majority of women in one northern state favouring home birth, which midwives and community members commented stemmed from low levels of awareness. The principle reason cited by women for home birth was the sudden onset of labour. Financial barriers, the lack of essential drugs and equipment, lack of transportation and the absence of staff, particularly at night, were also identified as barriers to accessing care. Our research highlights a number of barriers to accessing care exist, which are likely to have limited the potential for the MSS to have an impact. It suggests that in addition to scaling up the workforce through the MSS, efforts are also needed to

  20. Barriers and Enablers to the Use of Virtual Worlds in Higher Education: An Exploration of Educator Perceptions, Attitudes and Experiences

    Science.gov (United States)

    Gregory, Sue; Scutter, Sheila; Jacka, Lisa; McDonald, Marcus; Farley, Helen; Newman, Chris

    2015-01-01

    Three-dimensional (3D) virtual worlds have been used for more than a decade in higher education for teaching and learning. Since the 1980s, academics began using virtual worlds as an exciting and innovative new technology to provide their students with new learning experiences that were difficult to provide any other way. But since that time,…

  1. Levers and barriers to patient-centred care with children: findings from a synthesis of studies of the experiences of children living with type 1 diabetes or asthma.

    Science.gov (United States)

    Curtis-Tyler, K

    2011-07-01

    The last 50 years have seen a sea change in approaches to health care with children, from a time when children were routinely separated from parents while in hospital, to current recognition of the importance of placing the experiences of children and their families at the heart of care. Yet, there is a gap in the evidence about how children's involvement might be best achieved.This study aimed to synthesize findings of children's experiences of long-term illness and, from this, to identify levers and barriers to patient-centred care with children. A synthesis of studies of the experiences of children living with type 1 diabetes or asthma. Eight health and social care databases, bibliography searches and consultation with field experts and first authors of included studies. Qualitative studies with children 10 years (mean) and younger on their experiences of living with type 1 diabetes or asthma. Findings suggest key 'levers' to patient-centred care with children include: (1) engagement with children's expertise about their own lives: their personal and social experiences of their care, including how these are affected by their relative lack of power in some settings; (2) exploring children's understandings and preferences in terms of their physical sensations and day-to-day experiences; (3) willingness to find resources to engage with even the youngest children; (4) avoiding age-based assumptions about children's contributions to their care. Action on the above 'levers' may present a range of challenges in healthcare settings not least because it represents a move away from medicine's historical focus on children's developing competencies to engage rather with children's social realities from the earliest ages. © 2010 Blackwell Publishing Ltd.

  2. Diabetes and diet : managing dietary barriers

    NARCIS (Netherlands)

    Friele, R.D.

    1989-01-01

    This thesis reports on the barriers diabetic patients experience with their diet, and the ways they cope with these barriers. A dietary barrier is a hinderance to a person's well-being, induced by being advised a diet. First inventories were made of possible dietary barriers and ways of

  3. Students' voices: the lived experience of faculty incivility as a barrier to professional formation in associate degree nursing education.

    Science.gov (United States)

    Del Prato, Darlene

    2013-03-01

    Nursing faculty play an important role in constructing learning environments that foster the positive formation of future nurses. The students' construction of a nursing identity is grounded in social interactions with faculty and is shaped by values and norms learned in both the formal and informal curriculum. The informal curriculum is communicated in faculty teaching practices and relationships established with students. To acquire an understanding of the students' lived experience in associate degree nursing education and identify educational practices that support students' professional formation. A phenomenological design was chosen to study the lived experience of nursing education. In-depth interviews were conducted with 13 participants. Five students participated in second interviews for a total of 18 interviews. Symbolic interactionism guided data analysis. Participants represented three ADN programs in the northeastern U.S. and were diverse in terms of gender and age and to a lesser extent race, and sexual orientation. Faculty incivility included demeaning experiences, subjective evaluation, rigid expectations, and targeting and weeding out practices. Targeting practices contributed to a perceived focus on clinical evaluation and inhibited clinical learning. Faculty incivility hindered professional formation by interfering with learning, self-esteem, self-efficacy, and confidence. Faculty who model professional values in the formal and hidden curriculum contribute to the positive formation of future nurses. Nursing faculty should be formally prepared as educators to establish respectful, connected relationships with students. Faculty should role model professional values, deemphasize their evaluative role, provide constructive formative feedback, and remain open to the student's potential for growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Barriers and facilitators to participation in physical activity: The experiences of a group of South African adolescents with cerebral palsy.

    Science.gov (United States)

    Conchar, Lauren; Bantjes, Jason; Swartz, Leslie; Derman, Wayne

    2016-02-01

    Participation in regular physical activity promotes physical health and psychosocial well-being. Interventions are thus needed to promote physical activity, particularly among groups of individuals, such as persons with disability, who are marginalised from physical activity. This study explored the experiences of a group of South African adolescents with cerebral palsy. In-depth semi-structured interviews were conducted with 15 adolescents with cerebral palsy. The results provided insight into a range of factors that promote and hinder participation in physical activity among adolescents with cerebral palsy in resource-scarce environments. © The Author(s) 2014.

  5. Strike-slip pull-apart process and emplacement of Xiangshan uranium-producing volcanic basin

    International Nuclear Information System (INIS)

    Qiu Aijin; Guo Lingzhi; Shu Liangshu

    2001-01-01

    Xiangshan volcanic basin is one of the famous uranium-producing volcanic basins in China. Emplacement mechanism of Xiangshan uranium-producing volcanic basin is discussed on the basis of the latest research achievements of deep geology in Xiangshan area and the theory of continental dynamics. The study shows that volcanic activity in Xiangshan volcanic basin may be divided into two cycles, and its emplacement is controlled by strike-ship pull-apart process originated from the deep regional faults. Volcanic apparatus in the first cycle was emplaced in EW-trending structure activated by clockwise strike-slipping of NE-trending deep fault, forming the EW-trending fissure-type volcanic effusion belt. Volcanic apparatus in the second cycle was emplaced at junction points of SN-trending pull-apart structure activated by sinistral strike-slipping of NE-trending deep faults and EW-trending basement faults causing the center-type volcanic magma effusion and extrusion. Moreover, the formation mechanism of large-rich uranium deposits is discussed as well

  6. From Embodiment to Emplacement: Re-Thinking Competing Bodies, Senses and Spatialities

    Science.gov (United States)

    Pink, Sarah

    2011-01-01

    In this article I discuss how a shift from theories of embodiment to one of emplacement can inform how we understand the performing body in competitive and pedagogical contexts. I argue that recent theoretical advances concerning the senses, human perception and place offer new analytical possibilities for understanding skilled performances and…

  7. EVALUATION OF RISKS AND WASTE CHARACTERIZATION REQUIREMENTS FOR THE TRANSURANIC WASTE EMPLACED IN WIPP DURING 1999

    Energy Technology Data Exchange (ETDEWEB)

    Channell, J.K.; Walker, B.A.

    2000-05-01

    Specifically this report: 1. Compares requirements of the WAP that are pertinent from a technical viewpoint with the WIPP pre-Permit waste characterization program, 2. Presents the results of a risk analysis of the currently emplaced wastes. Expected and bounding risks from routine operations and possible accidents are evaluated; and 3. Provides conclusions and recommendations.

  8. Analysis of emplacement borehole rock and liner behavior for a repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Lorig, L.J.; Dasgupta, B.

    1989-09-01

    This report presents the results of studies aimed at assessing the quasi-static behavior of both the rock surrounding an emplacement borehole and the lining within an emplacement borehole for a nuclear waste repository in tuff. Two-dimensional thermomechanical analyses of conditions similar to those representative of the horizontal emplacement option were performed using a distinct element code. Three different behavior models (equivalent continuum, wedge, and parallel joint) were used to investigate the state of deformation at 0 and 100 years following waste emplacement. Three different rock strength assumptions were studied corresponding to ''design,'' ''recommended'' and ''limit'' values given in the Nevada Nuclear Waste Storage Investigation (NNWSI) Project Site Characterization Plan Conceptual Design Report (MacDougall et al., 1987). The ground reaction curve concept is introduced to study the potential liner loading resulting from thermally induced borehole closure. The report concludes that for the conditions and parameters assumed, liners may not be significantly loaded by borehole closure, because predicted closures will likely be less than tolerances required to install the lining. The report also concludes that gravity loading of linings by blocks which fall from the surrounding rock should not over-stress the lining. 25 refs., 51 figs., 14 tabs

  9. Emplacement and inflation of natrocarbonatitic lava flows during the March-April 2006 eruption of Oldoinyo Lengai, Tanzania

    Science.gov (United States)

    Mattsson, Hannes B.; Vuorinen, Jaana

    2009-04-01

    The most voluminous eruption of natrocarbonatite lava hitherto recorded on Earth occurred at Oldoinyo Lengai in March-April 2006. The lava flows produced in this eruption range from blocky 'a'a type to smooth-surfaced inflated pahoehoe. We measured lava inflation features (i.e. one tumulus and three pressure ridges) that formed in the various pahoehoe flows emplaced in this event. The inflation features within the main crater of Oldoinyo Lengai are relatively small-scale, measuring 1-5 m in width, 2.5-24.4 m in length and with inflation clefts less than 0.4 m deep. Their small sizes are in contrast to a tumulus that formed on the northwestern slope of the volcano (situated ~1140 m below the crater floor). The tumulus is roughly circular, measures 17.5 × 16.0 m, and is cut by a 4.4 m deep axial inflation cleft exposing two separate flow units. We measured the elastic properties (i.e. shear- and bulk moduli) of natrocarbonatitic crust and find that these are similar to those reported for basaltic crust, and that there is no direct correlation between magmastatic head and pressure required to form tumuli. All inflated flows in the 2006 event were confined by lateral barriers (main crater, erosional channel or erosional gully) suggesting that the two most important factors for endogenous growth in natrocarbonatitic lava flows are (1) lateral barriers that prevent widening of the flow, and (2) influx of new material beneath the viscoelastic and brittle crust.

  10. Palaeomagnetic Emplacement Temperature Determinations of Pyroclastic and Volcaniclastic Deposits in Southern African Kimberlite Pipes

    Science.gov (United States)

    Fontana, G.; Mac Niocaill, C.; Brown, R.; Sparks, R. S.; Matthew, F.; Gernon, T. M.

    2009-12-01

    Kimberlites are complex, ultramafic and diamond-bearing volcanic rocks preserved in volcanic pipes, dykes and craters. The formation of kimberlite pipes is a strongly debated issue and two principal theories have been proposed to explain pipe formation: (1) the explosive degassing of magma, and (2) the interaction of rising magma with groundwater (phreatomagmatism). Progressive thermal demagnetization studies are a powerful tool for determining the emplacement temperatures of ancient volcanic deposits and we present the first application of such techniques to kimberlite deposits. Lithic clasts were sampled from a variety of lithofacies, from three pipes for which the internal geology is well constrained (A/K1 pipe, Orapa Mine, Botswana and the K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions and layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Lithic clasts sampled from layered and massive vent-filling pyroclastic deposits in A/K1 were emplaced at >590° C. Results from K1 and K2 provide a maximum emplacement temperature limit for vent-filling breccias of 420-460° C; and constrain equilibrium deposit temperatures at 300-340° C. Crater-filling volcaniclastic kimberlite breccias and talus deposits from A/K1 were emplaced at ambient temperatures, consistent with infilling of the pipe by post-eruption epiclastic processes. Identified within the epiclastic crater-fill succession is a laterally extensive 15-20 metre thick kimberlite pyroclastic flow deposit emplaced at temperatures of 220-440° C. It overlies the post-eruption epiclastic units and is considered an extraneous pyroclastic kimberlite deposit erupted from another kimberlite vent. The results provide important constraints on kimberlite emplacement mechanisms and eruption dynamics. Emplacement temperatures of >590°C for pipe-filling pyroclastic deposits

  11. Barriers and post-closure monitoring (AL121125)

    International Nuclear Information System (INIS)

    Bostick, K.V.; Janecky, D.

    1995-01-01

    This project focuses on the rapid implementation of near-surface barriers, biotreatment, and post-closure monitoring technology. It uses water-permeable and biologic barriers that chemically capture and/or degrade contaminants without significantly altering the natural water flow regime. Barrier approaches are being tested for two different applications. The first is the use of barriers for confinement of chemical contaminants for in-trench treatments with leach systems or an in-place bioreactor. The second is an enhancement of the current practice of emplacing grout or clay slurry walls into direct horizontal surface and subsurface water flows around a contaminated area by integrating permeable reactive barriers and petroleum reservoir gel/foam/polymer technology

  12. Sill Emplacement and Forced Folding in the Canterbury Basin, offshore SE New Zealand

    Science.gov (United States)

    Reeves, Jennifer; Magee, Craig; Jackson, Christopher

    2017-04-01

    Sill-complexes are common in sedimentary basins worldwide. The geometry of sill-complexes and their associated deformation can be used to unravel tectono-magmatic events. For example, intruding magma may uplift the overburden and the free surface to produce forced folds that are typically either dome-shaped or flat-topped. These four-way dip closures can form suitable hydrocarbon traps and dating of onlapping of sedimentary strata allows the timing of emplacement, relative to hydrocarbon generation and migration to be assessed. Furthermore, these forced folds directly overlie the forcing intrusion and their volume is commonly assumed to equal that of the emplaced magma. This relationship between folds, which may be expressed that the Earth's surface, and magma volume is fundamental for volcano predication due to the use of ground deformation as a proxy for the location and magnitude of future eruptions. However, recent studies have demonstrated that fluidization of weak host rock can accommodate magma during non-brittle emplacement, producing little or no overburden deformation. Assessing the mechanics of intrusion-induced forced folding is therefore critical to a variety of Earth Science disciplines. Here, we use 3D seismic reflection data map four sills at a high-resolution within the underexplored Canterbury Basin, offshore SE New Zealand. We demonstrate that: (i) despite similar emplacement levels, forced folds are only developed above two of the sills, with no apparent uplift above the other two sills; (ii) onlap of sedimentary onto forced folds and associated hydrothermal vents indicates two episodes of sill emplacement in the Whaingaroan (34.6-31.8 Ma) and Opoitian (5.33-3.7 Ma); and (iii) intra-fold thickness is variable, with lower intervals within the folds displaying a flat-topped geometry overlain by sedimentary strata displaying dome-shaped folding. We discuss the formation of these forced folds as assess the role of non-brittle and inelastic

  13. The impact of language barriers and immigration status on the care experience for Spanish-speaking caregivers of patients with pediatric cancer.

    Science.gov (United States)

    Zamora, Eduardo R; Kaul, Sapna; Kirchhoff, Anne C; Gwilliam, Vannina; Jimenez, Ornella A; Morreall, Deborah K; Montenegro, Roberto E; Kinney, Anita Y; Fluchel, Mark N

    2016-12-01

    An increasing proportion of pediatric cancer patients in the United States are Latino and many have Spanish-speaking immigrant parents with limited English proficiency (LEP). Little is known about how language or undocumented immigration status impacts their care experience. A cross-sectional survey was administered to English (N = 310) and Spanish-speaking LEP (N = 56) caregivers of pediatric cancer patients. To assess differences in healthcare experiences between the language groups, t-tests and chi-square statistics were used. Multivariable logistic regression evaluated associations between primary language and knowledge of clinical trial status. Spanish-speaking caregivers were more likely to report higher rates of quitting or changing jobs as a direct result of their child's cancer, and their children were more likely to experience a delay in education. Although Spanish-speaking caregivers reported higher satisfaction with care, 32% reported feeling that their child would have received better care if English was their primary language. Spanish-speaking caregivers were more likely to incorrectly identify whether their child was on a clinical trial compared with English-speaking caregivers. The majority of Spanish-speaking caregivers reported at least one undocumented caregiver in the household and 11% of them avoided or delayed medical care for their child due to concerns over their undocumented immigration status. Language barriers and undocumented immigration status may negatively impact the quality of informed decision-making and the care experience for Spanish-speaking LEP caregivers of pediatric cancer patients. These families may benefit from culturally appropriate Spanish language resources to improve communication and open a dialogue regarding undocumented immigration status. © 2016 Wiley Periodicals, Inc.

  14. Doing battle with "the monster:" how high-risk heterosexuals experience and successfully manage HIV stigma as a barrier to HIV testing.

    Science.gov (United States)

    Gwadz, Marya; Leonard, Noelle R; Honig, Sylvie; Freeman, Robert; Kutnick, Alexandra; Ritchie, Amanda S

    2018-04-20

    Annual HIV testing is recommended for populations at-risk for HIV in the United States, including heterosexuals geographically connected to urban high-risk areas (HRA) with elevated rates of HIV prevalence and poverty, who are primarily African American/Black or Hispanic. Yet this subpopulation of "individuals residing in HRA" (IR-HRA) evidence low rates of regular HIV testing. HIV stigma is a recognized primary barrier to testing, in part due to its interaction with other stigmatized social identities. Guided by social-cognitive and intersectionality theories, this qualitative descriptive study explored stigma as a barrier to HIV testing and identified ways IR-HRA manage stigma. In 2012-2014, we conducted in-depth qualitative interviews with 31 adult IR-HRA (74% male, 84% African American/Black) with unknown or negative HIV status, purposively sampled from a larger study for maximum variation on HIV testing experiences. Interviews were audio-recorded and professionally transcribed verbatim. Data were analyzed using a systematic content analysis approach that was both theory-driven and inductive. Stigma was a primary barrier to HIV testing among IR-HRA. In the context of an under-resourced community, HIV stigma was experienced as emerging from, and being perpetuated by, health care organizations and educational institutions, as well as community members. Participants noted it was "better not to know" one's HIV status, to avoid experiencing HIV-related stigma, which could interact with other stigmatized social identities and threaten vital social relationships, life chances, and resources. Yet most had tested for HIV previously. Factors facilitating testing included health education to boost knowledge of effective treatments for HIV; understanding HIV does not necessitate ending social relationships; and tapping into altruism. In the context of economic and social inequality, HIV stigma operates on multiple, intersecting layers. IR-HRA struggle with an aversion to

  15. 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

  16. 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.

  17. The patient experience with DSM-5-defined binge eating disorder: characteristics, barriers to treatment, and implications for primary care physicians.

    Science.gov (United States)

    Herman, Barry K; Safikhani, Shima; Hengerer, David; Atkins, Norman; Kim, Andy; Cassidy, Daniel; Babcock, Thomas; Agus, Samuel; Lenderking, William R

    2014-09-01

    Binge eating disorder (BED) is now a formal diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). However, post-DSM-5 patient profiles and viewpoints on BED diagnosis and treatment remain unclear. This study used a focus group methodology to examine demographic and clinical characteristics, as well as perceptions of diagnosis and treatment from patients with BED symptoms who were either formally diagnosed with BED or undiagnosed. Binge eating disorder-diagnosed individuals (n = 11) or those meeting the DSM-5 BED diagnostic criteria but were undiagnosed (n = 14) participated in 6 semistructured focus groups conducted by trained staff at 3 geographic locations in the United States. Patients completed a series of demographic and clinical measures and then engaged in a moderated discussion focused on identifying factors associated with their experiences with BED. Sixty percent of the patients were female, 48% were white and 40% were black, and 76% were employed. The diagnosed group had a slightly higher socioeconomic status; undiagnosed patients had a higher average body mass index. In the overall sample, comorbid anxiety (40%) and depression (40%) were the most common psychiatric comorbidities. Even in the diagnosed group, only half of the patients (54.5%) became aware of BED through their health care provider (HCP; n = 6). Patients perceived that HCPs were focused more on physical ailments, were judgmental about weight, and were unable to distinguish BED from obesity. They also expressed a desire for safe, nonjudgmental interactions with HCPs. Education and income may be factors affecting access to care and BED diagnosis. Both patient groups reported considerable psychopathology and medical comorbidities. Moreover, the patient groups perceived HCPs as both having inadequate understanding of BED and providing insensitive and ineffective communication regarding eating behaviors. The study findings in diagnosed and undiagnosed

  18. View of physicians on and barriers to patient enrollment in a multicenter clinical trial: experience in a Japanese rural area

    Directory of Open Access Journals (Sweden)

    Yanagawa Hiroaki

    2010-06-01

    informed consent (58%, cumbersome procedures (58%, difficulty in long-term follow up (33%, and insufficient tools for explanation and obtaining informed consent (8%. Conclusion This survey showed that successful physician recruiters consider a support system with CRC of value, and that they are skillful in obtaining informed consent. These views and attitudes may have originated from past experience involving clinical trials. In this regard, we need to develop an infrastructure to enlighten physicians on this support system for the promotion of clinical trials.

  19. 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

  20. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock volume 1: summary

    International Nuclear Information System (INIS)

    Wikjord, A.G.; Baumgartner, P.; Johnson, L.H.; Stanchell, F.W.; Zach, R.; Goodwin, B.W.

    1996-06-01

    The concept for disposal of Canada's nuclear fuel waste involves isolating the waste in corrosion-resistant containers emplaced and sealed within a vault at a depth of 500 to 1000 m in plutonic rock of the Canadian Shield. The case for the acceptability of the concept as a means of safely disposing of Canada's nuclear fuel waste is presented in an Environmental Impact Statement (EIS) The disposal concept permits a choice of methods, materials, site locations and designs. The EIS presents a case study of the long-term (i.e., postclosure) performance of a hypothetical implementation of the concept, referred to in this report as the reference disposal system. The reference disposal system is based on borehole emplacement of used CANDU fuel in Grade-2 titanium alloy containers in low-permeability, sparsely fractured plutonic rock of the Canadian Shield. We evaluate the long-term performance of another hypothetical implementation of the concept based on in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. The geological characteristics of the geosphere assumed for this study result in short groundwater travel times from the disposal vault to the surface. In the present study, the principal barrier to the movement of contaminants is the long-lasting copper container. We show that the long-lasting container can effectively compensate for a permeable host rock which results in an unfavourable groundwater flow condition. These studies illustrate the flexibility of AECL's disposal concept to take advantage of the retention, delay, dispersion, dilution and radioactive decay of contaminants in a system of natural barriers provided by the geosphere and hydrosphere and of engineered barriers provided by the waste form, container, buffer, backfills, other vault seals and grouts. In an actual implementation, the engineered system would be designed for the geological conditions encountered at the host site. 34 refs., 2 tabs., 11 figs

  1. Emplacement technology for the direct disposal of spent fuel into deep vertical boreholes

    International Nuclear Information System (INIS)

    Bollingerfehr, W.; Filbert, W.; Wehrmann, J.

    2008-01-01

    In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a diameter of 60 cm and a depth of up to 300 m. In order to facilitate the fast encapsulation of the waste canister by the host rock (rock salt), no lining of the boreholes is planned. With regard to harmonize and optimize the emplacement technology for both categories of packages (vitrified waste and spent fuel) alternatives were developed. In this context the borehole emplacement technique for consolidated spent fuel as already foreseen for high-level reprocessing waste was reconsidered. This review resulted in the design of a new disposal package, a fuel rod canister (type 'BSK 3'), and an appropriate modified transport and emplacement technology. This concept (called BSK 3-concept) provides the following optimization possibilities: (i) A new steel canister of the same diameter (43 cm) as the standardized HLW canisters applied for high-level waste and compacted technological waste from reprocessing abroad can be filled with fuel rods of 3 PWR or 9 BWR fuel assemblies. (II) The standardized canister

  2. From steep feeders to tabular plutons - Emplacement controls of syntectonic granitoid plutons in the Damara Belt, Namibia

    Science.gov (United States)

    Hall, Duncan; Kisters, Alexander

    2016-01-01

    Granitoid plutons in the deeply eroded south Central Zone of the Damara Belt in Namibia commonly show tabular geometries and pronounced stratigraphic controls on their emplacement. Subhorizontal, sheet-like pluton geometries record emplacement during regional subhorizontal shortening, but the intrusion of spatially and temporally closely-related granitoid plutons at different structural levels and in distinct structural settings suggests independent controls on their levels of emplacement. We describe and evaluate the controls on the loci of the dyke-to-sill transition that initiated the emplacement of three syntectonic (560-530 Ma) plutons in the basement-cover stratigraphy of the Erongo region. Intrusive relationships highlight the significance of (1) rigidity anisotropies associated with competent sedimentary packages or pre-existing subhorizontal granite sheets and (2) rheological anisotropies associated with the presence of thick ductile marble horizons. These mechanical anisotropies may lead to the initial deflection of steep feeder conduits as well as subsequent pluton assembly by the repeated underaccretion of later magma batches. The upward displacement of regional isotherms due to the heat advection associated with granite emplacement is likely to have a profound effect on the mechanical stratification of the upper crust and, consequently, on the level at which granitoid pluton emplacement is initiated. In this way, pluton emplacement at progressively shallower crustal depths may have resulted in the unusually high apparent geothermal gradients recorded in the upper crustal levels of the Damara Belt during its later evolution.

  3. 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.

  4. Vanishing Frontiers: A Javanese Plantation Emplacement, 1870s – 2000s

    Directory of Open Access Journals (Sweden)

    Pujo Semedi Hargo Yuwono

    2018-02-01

    Full Text Available The introduction of the Agrarian Law of 1870 led hundreds of would-be Dutch planters to try their luck in the plantation business. Soon, dots of settlements where coolies from lowlands were housed emerged on the island map. Plantation emplacements were different from ordinary villages, as they were established mainly to keep the labor force ready to work. They were regimented villages. Using data collected from Jolotigo tea plantation in Central Java, this paper discusses how a plantation emplacement was established, reached its heyday, and eventually dissolved in the course of history. I will use this discussion to question the old thesis of the domination of workers by capitalistic enterprises. Is a capitalistic plantation company really powerful enough to control workers in order to guarantee its business interests?

  5. STRUCTURAL CALCULATION OF AN EMPLACEMENT PALLET STATICALLY LOADED BY A WASTE PACKAGE

    International Nuclear Information System (INIS)

    S. Mastilovic

    2000-01-01

    The purpose of this calculation is to determine the structural response of the emplacement pallet (EP) subjected to static load from the mounted waste package (WP). The scope of this document is limited to reporting the calculation results in terms of stress intensity magnitudes. This calculation is associated with the waste emplacement systems design; calculations are performed by the Waste Package Design group. AP-3.12Q, Revision 0, ICN 0, Calculations, is used to perform the calculation and develop the document. The finite element solutions are performed by using the commercially available ANSYS Version (V) 5.4 finite element code. The results of these calculations are provided in terms of maximum stress intensity magnitudes

  6. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-01-01

    The age of nuclear waste - the length of time between its removal from the reactor cores and its emplacement in a repository - is a significant factor in determining the thermal loading of a repository. The surface cooling period as well as the density and sequence of waste emplacement affects both the near-field repository structure and the far-field geologic environment. To investigate these issues, a comprehensive review was made of the available literature pertaining to thermal effects and thermal properties of mined geologic repositories. This included a careful evaluation of the effects of different surface cooling periods of the wastes, which is important for understanding the optimal thermal loading of a repository. The results led to a clearer understanding of the importance of surface cooling in evaluating the overall thermal effects of a radioactive waste repository. The principal findings from these investigations are summarized in this paper

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  8. Development of innovative medicinal drugs in Russia: possibilities, barriers and practices. Evaluations and experiences of representatives of science, business and governmental organisations (Originele titel is Russisch)

    NARCIS (Netherlands)

    Zvonareva, O.I.

    2015-01-01

    Разработка инновационных лекарственных препаратов в России: возможности, барьеры и практики. Оценки и опыт представителей науки,бизнеса и государственных организаций[Development of innovative medicinal drugs in Russia: possibilities, barriers and practices. Evaluations and experiences of

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  10. Emplacement temperatures of pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa

    Science.gov (United States)

    Fontana, Giovanni; Mac Niocaill, Conall; Brown, Richard J.; Sparks, R. Stephen J.; Field, Matthew

    2011-10-01

    Palaeomagnetic techniques for estimating the emplacement temperatures of volcanic deposits have been applied to pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa. Lithic clasts were sampled from a variety of lithofacies from three pipes for which the internal geology is well constrained (the Cretaceous A/K1 pipe, Orapa Mine, Botswana, and the Cambrian K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions, layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Basalt lithic clasts in the layered and massive vent-filling pyroclastic deposits in the A/K1 pipe at Orapa were emplaced at >570°C, in the pyroclastic crater-filling deposits at 200-440°C and in crater-filling talus breccias and volcaniclastic breccias at 560°C, although the interpretation of these results is hampered by the presence of Mesozoic magnetic overprints. These temperatures are comparable to the estimated emplacement temperatures of other kimberlite deposits and fall within the proposed stability field for common interstitial matrix mineral assemblages within vent-filling volcaniclastic kimberlites. The temperatures are also comparable to those obtained for pyroclastic deposits in other, silicic, volcanic systems. Because the lithic content of the studied deposits is 10-30%, the initial bulk temperature of the pyroclastic mixture of cold lithic clasts and juvenile kimberlite magma could have been 300-400°C hotter than the palaeomagnetic estimates. Together with the discovery of welded and agglutinated juvenile pyroclasts in some pyroclastic kimberlites, the palaeomagnetic results indicate that there are examples of kimberlites where phreatomagmatism did not play a major role in the generation of the pyroclastic deposits. This study indicates that palaeomagnetic methods can successfully distinguish differences in the

  11. Exploring physiotherapists' experiences of implementing a cognitive behavioural approach for managing low back pain and identifying barriers to long-term implementation.

    Science.gov (United States)

    Richmond, Helen; Hall, Amanda M; Hansen, Zara; Williamson, Esther; Davies, David; Lamb, Sarah E

    2018-03-01

    Our objectives were two-fold: (i) to describe physiotherapists' experiences of implementing a cognitive behavioural approach (CBA) for managing low back pain (LBP) after completing an extensive online training course (iBeST), and (ii) to identify how iBeST could be enhanced to support long-term implementation before scale up for widespread use. We conducted semi-structured interviews with 11 physiotherapists from six National Health Service departments in the Midlands, Oxfordshire and Derbyshire. Questions centred on (i) using iBeST to support implementation, (ii) what barriers they encountered to implementation and (iii) what of information or resources they required to support sustained implementation. Interviews were transcribed and thematically analysed using NVivo. Themes were categorised using the Theoretical Domains Framework (TDF). Evidence-based techniques were identified using the behaviour change technique taxonomy to target relevant TDF domains. Three themes emerged from interviews: anxieties about using a CBA, experiences of implementing a CBA, and sustainability for future implementation of a CBA. Themes crossed multiple TDF domains and indicated concerns with knowledge, beliefs about capabilities and consequences, social and professional roles, social influences, emotion, and environmental context and resources. We identified evidence-based strategies that may support sustainable implementation of a CBA for LBP in a physiotherapy setting. This study highlighted potential challenges for physiotherapists in the provision of evidence-based LBP care within the current UK NHS. Using the TDF provided the foundation to develop a tailored, evidence-based, implementation intervention to support long term use of a CBA by physiotherapists managing LBP within UK NHS outpatient departments. Copyright © 2017 Chartered Society of Physiotherapy. All rights reserved.

  12. pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef

    Science.gov (United States)

    Georgiou, Lucy; Falter, James; Trotter, Julie; Kline, David I.; Holcomb, Michael; Dove, Sophie G.; Hoegh-Guldberg, Ove; McCulloch, Malcolm

    2015-01-01

    Geochemical analyses (δ11B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼−0.05 to −0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ11B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ11B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4–8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges. PMID:26438833

  13. pH homeostasis during coral calcification in a free ocean CO2 enrichment (FOCE) experiment, Heron Island reef flat, Great Barrier Reef.

    Science.gov (United States)

    Georgiou, Lucy; Falter, James; Trotter, Julie; Kline, David I; Holcomb, Michael; Dove, Sophie G; Hoegh-Guldberg, Ove; McCulloch, Malcolm

    2015-10-27

    Geochemical analyses (δ(11)B and Sr/Ca) are reported for the coral Porites cylindrica grown within a free ocean carbon enrichment (FOCE) experiment, conducted on the Heron Island reef flat (Great Barrier Reef) for a 6-mo period from June to early December 2010. The FOCE experiment was designed to simulate the effects of CO2-driven acidification predicted to occur by the end of this century (scenario RCP4.5) while simultaneously maintaining the exposure of corals to natural variations in their environment under in situ conditions. Analyses of skeletal growth (measured from extension rates and skeletal density) showed no systematic differences between low-pH FOCE treatments (ΔpH = ∼-0.05 to -0.25 units below ambient) and present day controls (ΔpH = 0) for calcification rates or the pH of the calcifying fluid (pHcf); the latter was derived from boron isotopic compositions (δ(11)B) of the coral skeleton. Furthermore, individual nubbins exhibited near constant δ(11)B compositions along their primary apical growth axes (±0.02 pHcf units) regardless of the season or treatment. Thus, under the highly dynamic conditions of the Heron Island reef flat, P. cylindrica up-regulated the pH of its calcifying fluid (pHcf ∼8.4-8.6), with each nubbin having near-constant pHcf values independent of the large natural seasonal fluctuations of the reef flat waters (pH ∼7.7 to ∼8.3) or the superimposed FOCE treatments. This newly discovered phenomenon of pH homeostasis during calcification indicates that coral living in highly dynamic environments exert strong physiological controls on the carbonate chemistry of their calcifying fluid, implying a high degree of resilience to ocean acidification within the investigated ranges.

  14. Lunar mare deposits associated with the Orientale impact basin: New insights into mineralogy, history, mode of emplacement, and relation to Orientale Basin evolution from Moon Mineralogy Mapper (M3) data from Chandrayaan-1

    Science.gov (United States)

    Whitten, J.; Head, J.W.; Staid, M.; Pieters, C.M.; Mustard, J.; Clark, R.; Nettles, J.; Klima, R.L.; Taylor, L.

    2011-01-01

    Moon Mineralogy Mapper (M3) image and spectral reflectance data are combined to analyze mare basalt units in and adjacent to the Orientale multiring impact basin. Models are assessed for the relationships between basin formation and mare basalt emplacement. Mare basalt emplacement on the western nearside limb began prior to the Orientale event as evidenced by the presence of cryptomaria. The earliest post-Orientale-event mare basalt emplacement occurred in the center of the basin (Mare Orientale) and postdated the formation of the Orientale Basin by about 60-100 Ma. Over the next several hundred million years, basalt patches were emplaced first along the base of the Outer Rook ring (Lacus Veris) and then along the base of the Cordillera ring (Lacus Autumni), with some overlap in ages. The latest basalt patches are as young as some of the youngest basalt deposits on the lunar nearside. M3 data show several previously undetected mare patches on the southwestern margins of the basin interior. Regardless, the previously documented increase in mare abundance from the southwest toward the northeast is still prominent. We attribute this to crustal and lithospheric trends moving from the farside to the nearside, with correspondingly shallower density and thermal barriers to basaltic magma ascent and eruption toward the nearside. The wide range of model ages for Orientale mare deposits (3.70-1.66 Ga) mirrors the range of nearside mare ages, indicating that the small amount of mare fill in Orientale is not due to early cessation of mare emplacement but rather to limited volumes of extrusion for each phase during the entire period of nearside mare basalt volcanism. This suggests that nearside and farside source regions may be similar but that other factors, such as thermal and crustal thickness barriers to magma ascent and eruption, may be determining the abundance of surface deposits on the limbs and farside. The sequence, timing, and elevation of mare basalt deposits

  15. Field Features And Mode Of Emplacement Of Pegmatites Of Keffi Area North Central Nigeria

    Directory of Open Access Journals (Sweden)

    Tanko

    2015-04-01

    Full Text Available Abstract The Keffi area of North Central Nigeria hosts numerous pegmatite bodies which are related to the surrounding granitic intrusions islocated about 45 km east of the Federal Capital Territory Abuja Nigeria. Petrological investigation of the pegmatites and surrounding host rocks aimed at characterising and understanding field relations and mode of emplacement of the rocks with a view to assess their mineralisation potentials were carried out. From the field observations the pegmatites were characterised into 1 Pelitic schist-amphibolite hosted pegmatites and 2 Granitoids orthogneisses hosted pegmatites and the granites into 1 the Bakin Ayini biotite granites 2 the Angwan Madugu biotite-muscovite granites and 3 the Sabongida biotite-muscovite granites. It is clear that those discordantly emplaced in pelitic schists varied in shape and size with length and width ranging from 400-2000m and 2-20m respectively some are huge isolated sill-like and flat-lying whilst those hosted in orthogneisses are narrow ranging in length 40-1000m and width 1-4m crosscutting and vertically oriented along shear zones which suggest passive emplacement

  16. Design options for HLW repository operation technology. (2) Bentonite block forming and vertical emplacement

    International Nuclear Information System (INIS)

    Takao, Hajime; Takegahara, Tatsuhiro; Nakashima, Hitoshi; Asano, Hidekazu

    2011-01-01

    RWMC and JGC have been running an all-round R and D program for the period of 2000-2010 to develop the concept of Vertical Emplacement for disposal of vitrified waste. The conceptual design of its basic equipment was worked out in 2000, followed by forming the large-scale bentonite block in 2001-2004. Study has also been conducted on a mechanism to convey and position the large-scale block using a vacuum suction device. Subsequent to these developments, various technologies necessary for designing the Vertical Emplacement equipment have been reviewed, which would enhance engineering feasibility and reliability. Full-scale demonstration program under a joint research program with JAEA (Japan Atomic Energy Agency) started in 2008 with the twin objectives 1) supporting of public relations and 2) technical verification. The large-scale bentonite block and part of the full-scale Vertical Emplacement equipment are now on view at the Full-scale demonstration facility in Horonobe, Hokkaido, Japan. (author)

  17. Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

    International Nuclear Information System (INIS)

    Kalinina, Elena Arkadievna; Hardin, Ernest

    2015-01-01

    This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

  18. Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Kalinina, Elena Arkadievna; Hardin, Ernest

    2015-11-01

    This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

  19. Far-field thermomechanical response of argillaceous rock to emplacement of a nuclear-waste repository

    International Nuclear Information System (INIS)

    McVey, D.F.; Thomas, R.K.; Lappin, A.R.

    1980-08-01

    Before heat-producing wastes can be emplaced safely in any argillaceous rock, it will be necessary to understand the far-field thermal and thermomechanical response of this rock to waste emplacement. This report presents the results of a first series of calculations aimed at estimating the far-field response of argillite to waste emplacement. Because the thermal and mechanical properties of argillite are affected by its content of expandable clay, its behavior is briefly compared and contrasted with that of a shale having the same matrix thermal properties, but containing no expandable clay. Under this assumption, modeled temperatures are the same for the two rock types at equivalent power densities and reflect the large dependence of in-situ temperatures on both initial power density and waste type. Thermomechanical calculations indicate that inclusion of contraction behavior of expandable clays in the assumed argillite thermal expansion behavior results, in some cases, in generation of a large zone in and near the repository that has undergone volumetric contraction but is surrounded by uniformly compressive stresses. Information available to date indicates that this contraction would likely result in locally increased fluid permeability and decreased in-situ thermal conductivity, but might well be advantageous as regards radionuclide retention, because of the increased surface area within the contracted zone. Assumption of continuous and positive expansion behavior for the shale eliminates the near-repository contraction and tensional zones, but results in near-surface tensional zones directly above the repository

  20. Barrier Systems

    NARCIS (Netherlands)

    Heteren, S. van

    2015-01-01

    Barrier-system dynamics are a function of antecedent topography and substrate lithology, Relative sea-level (RSL) changes, sediment availability and type, climate, vegetation type and cover, and various aero- and hydrodynamic processes during fair-weather conditions and extreme events. Global change

  1. Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, P. [Swisstopo, Federal Office of Topography, Wabern (Switzerland); Bernier, F. [Federal Agency for Nuclear Control FANC, Brussels (Belgium); Birkholzer, J. [Lawrence Berkeley National Laboratory, Berkeley (United States); and others

    2017-04-15

    Geologic repositories for radioactive waste are designed as multi-barrier disposal systems that perform a number of functions including the long-term isolation and containment of waste from the human environment, and the attenuation of radionuclides released to the subsurface. The rock laboratory at Mont Terri (canton Jura, Switzerland) in the Opalinus Clay plays an important role in the development of such repositories. The experimental results gained in the last 20 years are used to study the possible evolution of a repository and investigate processes closely related to the safety functions of a repository hosted in a clay rock. At the same time, these experiments have increased our general knowledge of the complex behaviour of argillaceous formations in response to coupled hydrological, mechanical, thermal, chemical, and biological processes. After presenting the geological setting in and around the Mont Terri rock laboratory and an overview of the mineralogy and key properties of the Opalinus Clay, we give a brief overview of the key experiments that are described in more detail in the following research papers to this Special Issue of the Swiss Journal of Geosciences. These experiments aim to characterise the Opalinus Clay and estimate safety-relevant parameters, test procedures, and technologies for repository construction and waste emplacement. Other aspects covered are: bentonite buffer emplacement, high-pH concrete-clay interaction experiments, anaerobic steel corrosion with hydrogen formation, depletion of hydrogen by microbial activity, and finally, release of radionuclides into the bentonite buffer and the Opalinus Clay barrier. In the case of a spent fuel/high-level waste repository, the time considered in performance assessment for repository evolution is generally 1 million years, starting with a transient phase over the first 10,000 years and followed by an equilibrium phase. Experiments dealing with initial conditions, construction, and waste

  2. Thermal modeling of pluton emplacement and associated contact metamorphism:Parashi stock emplacement in the Serranía de Jarara (Alta Guajira, Colombia

    Directory of Open Access Journals (Sweden)

    Zuluaga C. Carlos A.

    2010-12-01

    Full Text Available

    In the northernmost portion of the Serrania de Jarara (Alta Guajira, Colombia, low - medium grade metamorphic rocks from the Etpana Metamorphic Suite were thermally affected by emplacement of a small calc-alkaline intrusion (Parashi Stock. Detailed petrographic analysis in collected rock samples across the NE and NW plutonic contacts show occurrences of textural and mineralogical changes in the country rock fabric that evidence contact metamorphism overprinting regional metamorphism of the Etpana Suite. These changes include growth of andalusite (chiastolite, calcic clinopyroxeneand amphibole porphyroblast crosscutting Sn+1 metamorphicfoliation. Hornblende-plagioclase barometry (ca. 3.1 kbar and cooling models for the stock show maximum time temperature evolution in the country rock at the interpreted depth of intrusion (ca. 11 km and help to evaluate the behavior of the country rock with the changing local geotherm.

  3. Differences in experiences of barriers to STI testing between clients of the internet-based diagnostic testing service GetCheckedOnline.com and an STI clinic in Vancouver, Canada.

    Science.gov (United States)

    Gilbert, Mark; Thomson, Kimberly; Salway, Travis; Haag, Devon; Grennan, Troy; Fairley, Christopher K; Buchner, Chris; Krajden, Mel; Kendall, Perry; Shoveller, Jean; Ogilvie, Gina

    2018-02-07

    Internet-based STI testing programmes may overcome barriers posed by in-clinic testing, though uptake could reflect social gradients. The role these services play in comparison to clinical testing services is unknown. We compared experiences of testing barriers between STI clinic clients to clients of GetCheckedOnline.com (GCO; where clients take a printed lab form to a lab). Our 10-month cross-sectional study was conducted after GCO was promoted to STI clinic clients and men who have sex with men (MSM). Clinic and GCO clients completed an online survey assessing testing barriers and facilitators; responses were compared using bivariate analysis (level of significance PSTI testing services to increasing test uptake. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Execution techniques for high level radioactive waste disposal. 7. Handling and emplacement procedure of waste, and backfilling procedure of disposal facility

    International Nuclear Information System (INIS)

    Shiozaki, Isao; Ogata, Nobuhide; Kanagawa, Tadashi; Deguchi, Akira; Takahashi, Yoshiaki; Takao, Hajime; Awano, Toshihiko; Kawamura, Hideki

    1999-01-01

    Based on the principle of radiation protection, we studied the handling and emplacement procedure of waste and buffer material. We showed the handling flow diagram, conceptual drawings of handling and emplacement facility in two cases of emplacement; vertical emplacement in pit and horizontal emplacement in tunnel. The procedure and material for backfilling and plugging have been studied and the optimum method of current technologies is selected. Regarding the tunnel supporting, the removal of concrete supporting mainly was studied. Finally, we showed our view of monitoring before and after the close of disposal facility. (author)

  5. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository. Baseline concept criteria specifications and mechanical failure probabilities

    International Nuclear Information System (INIS)

    Hudson, E.E.; McCleery, J.E.

    1979-05-01

    One of the integral elements of the Nuclear Waste Management Program is the material handling task of retrieving Canisters containing spent unreprocessed fuel from their emplacement in a deep geologic salt bed Depository. A study of the retrieval concept data base predicated this report. In this report, alternative concepts for the tasks are illustrated and critiqued, a baseline concept in scenario form is derived and basic retrieval subsystem specifications are presented with cyclic failure probabilities predicted. The report is based on the following assumptions: (a) during retrieval, a temporary radiation seal is placed over each Canister emplacement; (b) a sleeve, surrounding the Canister, was initially installed during the original emplacement; (c) the emplacement room's physical and environmental conditions established in this report are maintained while the task is performed

  6. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository. Baseline concept criteria specifications and mechanical failure probabilities

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.E.; McCleery, J.E.

    1979-05-01

    One of the integral elements of the Nuclear Waste Management Program is the material handling task of retrieving Canisters containing spent unreprocessed fuel from their emplacement in a deep geologic salt bed Depository. A study of the retrieval concept data base predicated this report. In this report, alternative concepts for the tasks are illustrated and critiqued, a baseline concept in scenario form is derived and basic retrieval subsystem specifications are presented with cyclic failure probabilities predicted. The report is based on the following assumptions: (a) during retrieval, a temporary radiation seal is placed over each Canister emplacement; (b) a sleeve, surrounding the Canister, was initially installed during the original emplacement; (c) the emplacement room's physical and environmental conditions established in this report are maintained while the task is performed.

  7. Emplacement Temperatures of Pyroclastic and Volcaniclastic Deposits in Kimberlite Pipes in Southern Africa: New constraints From Palaeomagnetic Measurements

    Science.gov (United States)

    Fontana, G. P.; Macniocaill, C.; Brown, R. J.; Sparks, S. R.; Field, M.; Gernon, T. M.

    2009-05-01

    Palaeomagnetic techniques for estimating the emplacement temperatures of volcanic deposits have been applied for the first time to pyroclastic and volcaniclastic deposits in kimberlite pipes in southern Africa. Lithic clasts were sampled from a variety of lithofacies, from three pipes for which the internal geology is well constrained (A/K1 pipe, Orapa Mine, Botswana and the K1 and K2 pipes, Venetia Mine, South Africa). The sampled deposits included massive and layered vent-filling breccias with varying abundances of lithic inclusions and layered crater-filling pyroclastic deposits, talus breccias and volcaniclastic breccias. Lithic clasts sampled from layered and massive vent-filling pyroclastic deposits in A/K1 were emplaced at >590° C. Results from K1 and K2 provide a maximum emplacement temperature limit for vent-filling breccias of 420-460° C; and constrain equilibrium deposit temperatures at 300-340° C. Crater-filling volcaniclastic kimberlite breccias and talus deposits from A/K1 were emplaced at ambient temperatures, consistent with infilling of the pipe by post-eruption epiclastic processes. Identified within the epiclastic crater- fill succession is a laterally extensive 15-20 metre thick kimberlite pyroclastic flow deposit emplaced at temperatures of 220-440° C. It overlies the post-eruption epiclastic units and is considered an extraneous pyroclastic kimberlite deposit erupted from another kimberlite vent. The emplacement temperature results are comparable to the estimated emplacement temperatures of other kimberlite deposits and pyroclastic deposits from other volcanic systems, and fall within the proposed stability field for common interstitial matrix mineral assemblages within vent-filling volcaniclastic kimberlites. This is in the range where welding and agglutination of juvenile pyroclasts occurs in other types of pyroclastic deposits. Such high emplacement temperatures for vent-filling pyroclastic deposits are consistent with volatile

  8. 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

  9. Degradation of concrete-based barriers by Mg-containing brines: From laboratory experiments via reactive transport modelling to overall safety analysis in repository scale

    Science.gov (United States)

    Niemeyer, Matthias; Wilhelm, Stefan; Hagemann, Sven; Xie, Mingliang; Wollrath, Jürgen; Preuss, Jürgen

    2010-05-01

    The Morsleben nuclear waste repository (ERAM) for low- and intermediate-level radioactive waste is located in an old rock salt and potash mine in Northern Germany. From 1971 to 1998, approximately 36 800 m3 of waste have been disposed of. Now, waste disposal is finished, and the repository has to be backfilled and sealed. The closure concept is based on extensive backfilling of the salt mine with an inexpensive concrete mixture. The major disposal areas, containing most of the waste, will be isolated from the rest of the mine building by sealing the connecting access tunnels. The good geological situation (an intact cap rock with very small flow rates) provides an excellent basic condition for a safe repository. However, the access of water to the remaining parts of the mine cannot be excluded. The brines that are formed in contact with potash salts will contain Mg in a concentration that depends on various factors and cannot be predicted. For backfill and closure of the repository, no common material chemically stable against brines of all possible compositions is available. Salt concrete has a low permeability but is corroded by brines containing Mg, whilst concrete based on Sorel phases is decomposed if the Mg-content of the brines is too low. In each of these alternatives, corrosion results in a strong increase of permeability and a loss of the mechanical integrity of the material. However, for large hydraulic seals the flow of corroding brines is limited because of the high hydraulic resistance of the barrier. Thus, the barriers will persist for a long time in spite of the chemical incompatibility of building material and brine. For the planning of the backfill and closure measures as well as for the license application procedure it is crucial to demonstrate that the seals of the major disposal areas will keep their function for a sufficient long time. This lifetime depends among others on the corrosion capacity of the brine to the building material, on the

  10. The Swedish Concept for Disposal of Spent Nuclear Fuel: Differences Between Vertical and Horizontal Waste Canister Emplacement

    International Nuclear Information System (INIS)

    Bennett, D.G.; Hicks, T.W.

    2005-10-01

    The Swedish Nuclear Power Inspectorate (SKI) is preparing for the review of licence applications related to the disposal of spent nuclear fuel. The Swedish Nuclear Fuel and Waste Management Company (SKB) refers to its proposals for the disposal of spent nuclear fuel as the KBS-3 concept. In the KBS-3 concept, SKB plans that, after 30 to 40 years of interim storage, spent fuel will be disposed of at a depth of about 500 m in crystalline bedrock, surrounded by a system of engineered barriers. The principle barrier to radionuclide release is a cylindrical copper canister. Within the copper canister, the spent fuel is supported by a cast iron insert. Outside the copper canister is a layer of bentonite clay, known as the buffer, which is designed to provide mechanical protection for the canisters and to limit the access of groundwater and corrosive substances to their surfaces. The bentonite buffer is also designed to sorb radionuclides released from the canisters, and to filter any colloids that may form within the waste. SKB is expected to base its forthcoming licence applications on a repository design in which the waste canisters are emplaced in vertical boreholes (KBS-3V). However, SKB has also indicated that it might be possible and, in some respects, beneficial to dispose of the waste canisters in horizontal tunnels (KBS-3H). There are many similarities between the KBS-3V and KBS-3H designs. There are, however, uncertainties associated with both of the designs and, when compared, both possess relative advantages and disadvantages. SKB has identified many of the key factors that will determine the evolution of a KBS-3H repository and has plans for research and development work in many of the areas where the differences between the KBS-3V and KBS-3H designs mean that they could be significant in terms of repository performance. With respect to the KBS-3H design, key technical issues are associated with: 1. The accuracy of deposition drift construction. 2. Water

  11. Deformation of poorly consolidated sediment during shallow emplacement of a basalt sill, Coso Range, California

    Science.gov (United States)

    Duffield, W.A.; Bacon, C.R.; Delaney, P.T.

    1986-01-01

    A 150-m-long, wedge-shaped unit of folded and faulted marly siltstone crops out between undeformed sedimentary rocks on the north flank of the Coso Range, California. The several-meter-thick blunt end of this wedge abuts the north margin of a basaltic sill of comparable thickness. Chaotically deformed siltstone crops out locally at the margin of this sill, and at one locality breccia pipes about one meter in diameter crosscut the sill. The sill extends about 1 km south up the paleoslope, where it merges through continuous outcrop with a lava flow that in turn extends 1.4 km to a vent area marked by more than 100 m of agglutinate and scoria. Apparently, lava extruded at this vent flowed onto unconsolidated sediments, burrowed into them, and fed a sill at about 40 m depth within the sedimentary sequence. The sill initially propagated by wedging between sedimentary beds, but eventually began to push some beds ahead of itself, forming a remarkable train of folds in the process. The sediments apparently were wet at the time of sill emplacement, because hydrothermal alteration is common near the contact between the two rock types and because the breccia pipes that crosscut the sill apparently resulted from phreatic explosions of pore water heated at the base of the cooling sill. Comparison of deformation of the host material at the Coso locality with that reportedly caused by emplacement of sills elsewhere indicates that the character of deformation differs greatly among the various localities. The specific response of host material depends upon such parameters as initial properties of magma and host material, rate of sill growth and attendant rate of strain of host material, and depth of sill emplacement. Some properties may change considerably during an intrusive-deformational episode, thus complicating accurate reconstruction of such an event. ?? 1986 Springer-Verlag.

  12. The Summer 1997 Eruption at Pillan Patera on Io: Implications for Ultrabasic Lava Flow Emplacement

    Science.gov (United States)

    Williams, David A.; Davies, Ashley G.; Keszthelyi, Laszlo P.; Greeley, Ronald

    2001-01-01

    Galileo data and numerical modeling were used to investigate the summer 1977 eruption at Pillan Patera on Io. This event, now defined as "Pillanian" eruption style, included a high-temperature (greater than 1600 C), possible ultrabasic , 140-km-high plume eruption that deposited dark, orthopyroxene-rich pyroclastic material over greater than 125,000 sq km, followed by emplacement of dark flow-like material over greater than 3100 sq km to the north of the caldera. We estimate that the high-temperature, energetic episode of this eruption had a duration of 52 - 167 days between May and September 1997, with peak eruption temperatures around June 28, 1997. Galileo 20 m/pixel images of part of the Pillan flow field show a wide-spread, rough, pitted surface that is unlike any flow surface we have seen before. We suggest that this surface may have resulted from: 1. A fractured lava crust formed during rapid, low-viscosity lava surging, perhaps including turbulent flow emplacement. 2. Disruption of the lava flow by explosive interaction with a volatile-rich substrate. or 3. A combination of 1 and 2 with or without accumulation of pyroclastic material on the surface. Well-developed flow lobes are observed, suggesting that this is a relatively distant part of the flow field.Shadow measurements at flow margins indicate a thickness of-8 - 10 m. We have modeled the emplacement of putative ultrabasic flow from the summer 1997 Pillan eruption using constraints from new Galileo data. Results suggest that either laminar sheet flows or turbulent channelized flows could have traveled 50 - 150 km on a flat, unobstructed surface, which is consistent with the estimated length of the Pillan flow field (approx. 60 km). Our modeling suggests low thermal erosion rates (less than 4.1 m/d), and that the formation of deep (greater than 20 m) erosion channels was unlikely, especially distal to the source. We calculate a volumetric flow rate of approx. 2 - 7 x 10(exp 3)cu m/s, which is greater

  13. Étude de l'emplacement des produits agricoles sur les principaux ...

    African Journals Online (AJOL)

    L'emplacement est un facteur important de réussite de la commercialisation des produits agricoles sur les marchés publics. Cette étude a été initiée dans le but de contribuer à une meilleure organisation spatiale des points de vente de céréales sur les principaux marchés de Lomé. Elle a été faite à l'aide d'une enquête de ...

  14. A review of the ascent and emplacement of granitoid bodies into the crust

    Directory of Open Access Journals (Sweden)

    Katarína Bónová

    2005-03-01

    Full Text Available This paper relates to basic information (i.e. mechanical aspects of ascent, indicators faciliting the discriminability of various ascent styles about the models of ascent and emplacement of granitoid bodies, since the purely mechanical aspect of intrusion of magmas is a fascinating subject and it has generated a considerable controversy over many years. Individual models are demonstrated by world-known occurrences and examples from Western Carpathian’s region. The conditions of magma migration are demonstrated as well.

  15. A feasibility study of the disposal of radioactive waste in deep ocean sediments by drilled emplacement

    International Nuclear Information System (INIS)

    Bury, M.R.C.

    1983-08-01

    This report describes the second phase of a study of the feasibility of disposal and isolation of high level radioactive waste in holes drilled deep into the sediments of the ocean. In this phase, work has concentrated on establishing the state of the art of the various operations and developing the design, in particular the drilling operation, the loading of flasks containing waste canisters from supply vessels onto the platform, the handling of radioactive waste on board, and its emplacement into predrilled holes. In addition, an outline design of the offshore platform has been prepared. (author)

  16. Feasibility study of tank leakage mitigation using subsurface barriers

    Energy Technology Data Exchange (ETDEWEB)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F. [Ensearch Environmental, Inc. (United States); Rouse, J.K.; McLaughlin, T.J. [Bovay Northwest, Inc., Richland, WA (United States); Cruse, J.M. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-09-21

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report.

  17. Feasibility study of tank leakage mitigation using subsurface barriers

    International Nuclear Information System (INIS)

    Treat, R.L.; Peters, B.B.; Cameron, R.J.; McCormak, W.D.; Trenkler, T.; Walters, M.F.; Rouse, J.K.; McLaughlin, T.J.; Cruse, J.M.

    1994-01-01

    The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) to satisfy manage and dispose of the waste currently stored in the underground storage tanks. The retrieval element of TWRS includes a work scope to develop subsurface impermeable barriers beneath SSTs. The barriers could serve as a means to contain leakage that may result from waste retrieval operations and could also support site closure activities by facilitating cleanup. Three types of subsurface barrier systems have emerged for further consideration: (1) chemical grout, (2) freeze walls, and (3) desiccant, represented in this feasibility study as a circulating air barrier. This report contains analyses of the costs and relative risks associated with combinations retrieval technologies and barrier technologies that from 14 alternatives. Eight of the alternatives include the use of subsurface barriers; the remaining six nonbarrier alternative are included in order to compare the costs, relative risks and other values of retrieval with subsurface barriers. Each alternative includes various combinations of technologies that can impact the risks associated with future contamination of the groundwater beneath the Hanford Site to varying degrees. Other potential risks associated with these alternatives, such as those related to accidents and airborne contamination resulting from retrieval and barrier emplacement operations, are not quantitatively evaluated in this report

  18. Chiropractors` experience and readiness to work in Indigenous Australian Communities: a preliminary cross-sectional survey to explore preparedness, perceived barriers and facilitators for chiropractors practising cross-culturally

    OpenAIRE

    Vindigni, Dein; Polus, Barbara I.; Cleary, Sonja; Doyle, Aunty Kerrie

    2017-01-01

    Background Indigenous people make up approximately 3% of the total Australian population and score poorer on all health indices, including back pain. Chiropractors are well placed to alleviate back pain, yet there is no research that considers chiropractors? readiness to treat Indigenous patients. This study explores chiropractors` experience working with Indigenous Australians, describes perceived barriers and facilitators to chiropractors? participation in Indigenous Healthcare and their wi...

  19. Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

    Science.gov (United States)

    Vye-Brown, C.; Self, S.; Barry, T. L.

    2013-03-01

    The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

  20. Employment and Adults Who Are Deaf or Hard of Hearing: Current Status and Experiences of Barriers, Accommodations, and Stress in the Workplace.

    Science.gov (United States)

    Punch, Renée

    2016-01-01

    In an integrative review of the literature covering the period 2004-2016, the author presents a current picture of the situation of people who are deaf or hard of hearing (DHH) relative to employment and careers-particularly the barriers, facilitators, and stress levels experienced by working DHH adults. First, an overview is provided of findings from recent reports on employment outcomes for people who are DHH. Second, the author reviews the literature on employment and workplace barriers, facilitators, and accommodations for people who are DHH, and relates findings about DHH people's workplace-related stress and fatigue levels and the associated issues of job demand, job control, and social support in the workplace. The article concludes with a discussion of the implications of these findings, in particular the ways in which barriers to full participation of DHH people in the labor market can be addressed.

  1. A comprehensive review of the barriers and promoters health workers experience in delivering prevention of vertical transmission of HIV services in sub-Saharan Africa.

    Science.gov (United States)

    Schuster, Roseanne C; McMahon, Devon E; Young, Sera L

    2016-01-01

    Despite significant biomedical and policy advances, 199,000 infants and young children in sub-Saharan Africa (SSA) became infected with HIV in 2013, indicating challenges to implementation of these advances. To understand the nature of these challenges, we sought to (1) characterize the barriers and facilitators that health workers encountered delivering prevention of vertical transmission of HIV (PVT) services in SSA and (2) evaluate the use of theory to guide PVT service delivery. The PubMed and CINAHL databases were searched using keywords barriers, facilitators, HIV, prevention of vertical transmission of HIV, health workers, and their synonyms to identify relevant studies. Barriers and facilitators were coded at ecological levels according to the Determinants of Performance framework. Factors in this framework were then classified as affecting motivation, opportunity, or ability, per the Motivation-Opportunity-Ability (MOA) framework in order to evaluate domains of health worker performance within each ecological level. We found that the most frequently reported challenges occurred within the health facility level and spanned all three MOA domains. Barriers reported in 30% or more of studies from most proximal to distal included those affecting health worker motivation (stress, burnout, depression), patient opportunity (stigma), work opportunity (poor referral systems), health facility opportunity (overburdened workload, lack of supplies), and health facility ability (inadequate PVT training, inconsistent breastfeeding messages). Facilitators were reported in lower frequencies than barriers and tended to be resolutions to challenges (e.g., quality supervision, consistent supplies) or responses to an intervention (e.g., record systems and infrastructure improvements). The majority of studies did not use theory to guide study design or implementation. Interventions addressing health workers' multiple ecological levels of interactions, particularly the health

  2. Demonstration of close-coupled barriers for subsurface containment of buried waste

    International Nuclear Information System (INIS)

    Dwyer, B.P.; Heiser, J.; Stewart, W.

    1996-01-01

    The primary objective of this project is to develop and demonstrate a close-coupled barrier for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional cement grout curtain followed by a thin inner lining of a polymer grout. The resultant barrier is a cement polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. Close-coupled barrier technology is applicable for final, interim, or emergency containment of subsurface waste forms. Consequently, when considering the diversity of technology application, the construction emplacement and material technology maturity, general site operational requirements, and regulatory compliance incentives, the close-coupled barrier system provides an alternative for any hazardous or mixed waste remediation plan. This paper discusses the installation of a close-coupled barrier and the subsequent integrity verification

  3. Effects of annular air gaps surrounding an emplaced nuclear waste canister in deep geologic storage

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, W.E.; Davis, B.W.; Cheung, H.

    1980-06-05

    Annular air spaces surrounding an emplaced nuclear waste canister in deep geologic storage will have significant effects on the long-term performance of the waste form. Addressed specifically in this analysis is the influence of a gap on the thermal response of the waste package. Three dimensional numerical modeling predicts temperature effects for a series of parameter variations, including the influence of gap size, surface emissivities, initial thermal power generation of the canister, and the presence/absence of a sleeve. Particular emphasis is placed on determining the effects these variables have on the canister surface temperature. We have identified critical gap sizes at which the peak transient temperature occurs when gap widths are varied for a range of power levels. It is also shown that high emissivities for the heat exchanging surfaces are desirable, while that of the canister surface has the greatest influence. Gap effects are more pronounced, and therefore more effort should be devoted to optimal design, in situations where the absolute temperature of the near field medium is high. This occurs for higher power level emplacements and in geomedia with low thermal conductivities. Finally, loosely inserting a sleeve in the borehole effectively creates two gaps and drastically raises the canister peak temperature. It is possible to use these results in the design of an optimum package configuration which will maintain the canister at acceptable temperature levels. A discussion is provided which relates these findings to NRC regulatory considerations.

  4. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses

    International Nuclear Information System (INIS)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs

  5. The geology and emplacement history of the Pigeon kimberlite, EKATI Diamond Mine, Northwest Territories, Canada

    Science.gov (United States)

    Crawford, Barbara; Hetman, Casey; Nowicki, Tom; Baumgartner, Mike; Harrison, Sara

    2009-11-01

    The Pigeon kimberlite is located approximately 6 km to the northwest of the Koala cluster of the EKATI Diamond Mine, and is presently one of ten kimberlite occurrences in the EKATI resource development plan. It was emplaced along a regional lithological contact between syn-Yellowknife Supergroup granitoid rocks and Yellowknife Supergroup metasedimentary rocks that were covered by a now eroded veneer of poorly consolidated muddy sediments. Detailed age dating has not been undertaken, however the emplacement age is inferred from sedimentary xenoliths present within the pipe to range between 45-75 Ma. Pigeon is a small kimberlite body, estimated to be approximately 3.5 ha at surface, consisting of a steep-sided pipe that can be separated into four main geological domains that are characterized by contrasting textures, different diamond characteristics and unique mineral abundance and compositional signatures. The uppermost portion of the body consists of mud-rich resedimented volcaniclastic kimberlite that was formed by the deposition of extra crater deposits by debris flow type processes into an open diatreme. Texturally complex kimberlite is present within the lower portion of the kimberlite and includes rocks that display a range of features consistent with coherent (magmatic) and less common volcaniclastic (fragmental) rocks. This texturally complex zone is interpreted to represent a clastogenic deposit formed by a low energy eruption within an open diatreme.

  6. Emplacement of a Thick Mafic Extrusive Body: A CSD Solution to a Map-Generated Question

    Science.gov (United States)

    Pollock, M.; Sloan, J. A.; Siler, D. L.; Karson, J.

    2011-12-01

    A petrological study of crystallization in thick extrusive bodies is motivated by the geologic mapping of glacially excavated volcanic crust exposed along the Vatnsdalsfjall mountain range in northwest Iceland. Vatnsdalsfjall reveals a regional flexure zone, in which ~7 Ma lava flows dip 5-10° westward toward the extinct Skagi-Hunafloi rift axis. The regional flexure is disrupted by a local bowl-shaped depression, where lava flows steepen to ~50° as they dip below a ~250 m thick, ~3 km long igneous unit known as the Hjallin lens (HL). Its lenticular shape and well-developed columnar jointing most likely led Annels (1968) to initially map the HL as a shallow-level intrusion. However, more recent field investigations by McClanahan and Wobus (2004) reveal that the HL is an extrusive body, as evidenced by a distinct basal contact that consists of a flow-banded rhyolitic ash flow tuff underlain by a sedimentary layer containing organic material. Based on preliminary petrologic and geochemical analyses, McClanahan and Wobus (2004) describe the HL as a fine-grained, aphyric basalt that is nearly uniform in mineralogy, texture, and composition. Further field work by Siler (2011) shows that the HL overlies basaltic lavas that thicken toward the center of the bowl-shaped depression, indicating that the lava flows were emplaced during subsidence. The mapped relationship of the HL to the underlying lava flows suggests that the lens is a syn- (or post-) subsidence extrusion emplaced into an existing paleotopographic low. When considered with the field relationships, the homogeneous and fine-grained character of the lens naturally presents a petrological question: Was the anomalously thick extrusive body emplaced in a single eruptive event or is the HL the product of multiple flows that erupted in rapid succession? To understand the formation the HL, we measured the crystal size distribution (CSD) of plagioclase in backscattered electron (BSE) images of 20 samples from three

  7. Barriers to the provision of high-quality palliative care for people with dementia in England: a qualitative study of professionals' experiences

    NARCIS (Netherlands)

    Davies, N.; Maio, L.; Vedavanam, K.; Manthorpe, J.; Vernooij-Dassen, M.J.F.J.; Iliffe, S.

    2014-01-01

    Approaches to palliative care that were originally developed for people with cancer are now being adopted for people with dementia, as a response to many reports of poor-quality care for people with dementia at the end of life. This study explored perceived barriers to the delivery of high-quality

  8. Evaluation of emplacement sensors for detecting radiation and volatile organic compounds and for long-term monitoring access tubes for the BWCS

    International Nuclear Information System (INIS)

    Lord, D.L.; Averill, R.H.

    1997-10-01

    This document evaluates sensors for detecting contaminants in the excavated waste generated by the Buried Waste Containment System (BWCS). The Barrier Placement Machine (BPM) removes spoils from under a landfill or plume and places it on a conveyor belt on the left and right sides of the BPM. The spoils will travel down the conveyor belts past assay monitors and be deposited on top of the site being worked. The belts are 5 ft wide and transport approximately 15 ft3 /minute of spoils. This corresponds to a 10 ft per hour BPM advance rate. With a 2 in. spoils height the belt speed would be 3.6 in. per second. The spoils being removed are expected to be open-quotes cleanclose quotes (no radiation or volatile organics above background levels). To ensure that the equipment is not digging through a contaminated area, assay equipment will monitor the spoils for mg radiation and volatile organic compounds (VOCs). The radiation monitors will check for gross radiation indication. Upon detection of radiation levels above a predetermined setpoint, further evaluation will be performed to determine the isotopes present and their quantity. This will require hand held monitors and a remote monitoring station. Simultaneously, VOC monitors will monitor for predetermined volatile/semi-volatile organic compounds. A Fourier-Transform Infrared Spectrometer (FTIR) monitor is recommended for this operation. Specific site requirements and regulations will determine setpoints and operation scenarios. If VOCs are detected, the data will be collected and recorded. A flat panel display will be mounted in the BPM operator''s cab showing the radio nuclide and VOC monitoring data. As the BPM advances, a 3-in. diameter PVC tube will be placed on the bottom of the barrier slot in front of the 12 to 16-in. containment barrier being emplaced

  9. The mode of emplacement of Neogene flood basalts in eastern Iceland: Facies architecture and structure of simple aphyric basalt groups

    Science.gov (United States)

    Óskarsson, Birgir V.; Riishuus, Morten S.

    2014-12-01

    Simple flows (tabular) in the Neogene flood basalt sections of Iceland are described and their mode of emplacement assessed. The flows belong to three aphyric basalt groups: the Kumlafell group, the Hólmatindur group and the Hjálmadalur group. The groups can be traced over 50 km and originate in the Breiðdalur-Thingmuli volcanic zone. The groups have flow fields that display mixed volcanic facies architecture and can be classified after dominating type morphology. The Kumlafell and the Hólmatindur groups have predominantly simple flows of pāhoehoe and rubbly pāhoehoe morphologies with minor compound or lobate pāhoehoe flows. The Hjálmadalur group has simple flows of rubbly pāhoehoe, but also includes minor compound or lobate flows of rubble and 'a'ā. Simple flows are most common in the distal and medial areas from the vents, while more lobate flows in proximal areas. The simple flows are formed by extensive sheet lobes that are several kilometers long with plane-parallel contacts, some reaching thicknesses of ~ 40 m (aspect ratios structures. Their internal structure consists generally of a simple upper vesicular crust, a dense core and a thin basal vesicular zone. The brecciated flow-top is formed by clinker and crustal rubble, the clinker often welded or agglutinated. The simple flows erupted from seemingly short-lived fissures and have the characteristics of cooling-limited flows. We estimate the effusion rates to be ~ 105 m3/s for the simple flows of the Kumlafell and Hólmatindur groups and ~ 104 m3/s for the Hjálmadalur group. The longest flows advanced 15-20 km from the fissures, with lava streams of fast propagating flows inducing tearing and brecciation of the chilled crust. Compound or lobate areas appear to reflect areas of low effusion rates or the interaction of the lava with topographic barriers or wetlands, resulting in chaotic flowage. Slowing lobes with brecciated flow-tops developed into 'a'ā flows. The groups interdigitated with lava

  10. Magma traps and driving pressure: consequences for pluton shape and emplacement in an extensional regime

    Science.gov (United States)

    Hogan, John P.; Price, Jonathan D.; Gilbert, M. Charles

    1998-09-01

    The level of emplacement and final form of felsic and mafic igneous rocks of the Wichita Mountains Igneous Province, southwestern Oklahoma, U.S.A. are discussed in light of magma driving pressure, lithostatic load, and crustal magma traps. Deposition of voluminous A-type rhyolites upon an eroded gabbroic substrate formed a subhorizontal strength anisotropy that acted as a crustal magma trap for subsequent rising felsic and mafic magma. Intruded along this crustal magma trap are the A-type sheet granites (length/thickness 100:1) of the Wichita Granite Group, of which the Mount Scott Granite sheet is typical, and smaller plutons of biotite bearing Roosevelt Gabbro. In marked contrast to the subhorizontal granite sheets, the gabbro plutons form more equant stocks with flat roofs and steep side walls. Late Diabase dikes cross-cut all other units, but accompanying basaltic flows are extremely rare in the volcanic pile. Based on magmastatic calculations, we draw the following conclusions concerning the level of emplacement and the shape of these intrusions. (1) Magma can rise to a depth at which the magma driving pressure becomes negligible. Magma that maintains a positive driving pressure at the surface has the potential to erupt. (2) Magma ascent may be arrested at a deeper level in the crust by a subhorizontal strength anisotropy (i.e. crustal magma trap) if the magma driving pressure is greater than or equal to the lithostatic load at the depth of the subhorizontal strength anisotropy. (3) Subhorizontal sheet-intrusions form along crustal magma traps when the magma driving pressure greatly exceeds the lithostatic load. Under such conditions, the magma driving pressure is sufficent to lift the overburden to create the necessary space for the intrusion. (4) Thicker steep-sided stocks or batholiths, with flat roofs, form at crustal magma traps when the magma driving pressure approximates that of the lithostatic load. Under these conditions, the necessary space for the

  11. The internal geology and emplacement history of the Renard 2 kimberlite, Superior Province, Quebec, Canada

    Science.gov (United States)

    Fitzgerald, C. E.; Hetman, C. M.; Lepine, I.; Skelton, D. S.; McCandless, T. E.

    2009-11-01

    The Renard 2 kimberlite is located in the Otish Mountains region of Quebec, Canada and is one of the largest pipes in the Renard cluster. The cluster consists of nine kimberlite bodies and was discovered in 2001 by Ashton Mining of Canada Inc. and its joint venture partner SOQUEM Inc. Renard 2 was emplaced into Archean meta-greywacke derived migmatite, gneiss and granite of the Opinaca Subprovince of the eastern Superior Province at approximately 640.5 ± 2.8 Ma. An undetermined amount of erosion has occurred since emplacement with the present surface expression of the pipe estimated to be 0.75 ha. This kimberlite is interpreted as a steep-sided diatreme with minor irregularities in the external shape. The dominant infill is a massive volcaniclastic kimberlite (MVK) that is classified as tuffisitic kimberlite breccia (TKB) and is characterized by a high proportion of granitoid country rock xenoliths. A second dominant infill is a texturally complex, less diluted coherent kimberlite (CK) characterized locally by a transitional textures between CK and TKB. Surrounding the diatreme is a significant zone of variable width comprised of extensively brecciated country rock (+/-kimberlite) and referred to as marginal breccia. In addition to the two main rock types infilling the pipe, a number of hypabyssal kimberlite (HK) dykes and irregular shaped intrusions occur throughout the body, along the pipe contacts, within the marginal breccia and in the surrounding country rock. Geological features displayed by Renard 2 are similar to those described from Class 1 kimberlites of the Kimberley area of South Africa, the Gahcho Kué cluster of Canada and the Pimenta Bueno kimberlite field of Brazil. The economic evaluation of Renard 2 is in progress and to date has included extensive diamond and reverse circulation drilling as well as the collection of an underground bulk sample. Results from material sampled from Renard 2, including a 2449 tonne bulk sample, suggest Renard 2 has

  12. 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.

  13. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    International Nuclear Information System (INIS)

    Jarek, R.

    2004-01-01

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

  14. Early experiences on the feasibility, acceptability, and use of malaria rapid diagnostic tests at peripheral health centres in Uganda-insights into some barriers and facilitators

    Directory of Open Access Journals (Sweden)

    Asiimwe Caroline

    2012-01-01

    Full Text Available Abstract Background While feasibility of new health technologies in well-resourced healthcare settings is extensively documented, it is largely unknown in low-resourced settings. Uganda's decision to deploy and scale up malaria rapid diagnostic tests (mRDTs in public health facilities and at the community level provides a useful entry point for documenting field experience, acceptance, and predictive variables for technology acceptance and use. These findings are important in informing implementation of new health technologies, plans, and budgets in low-resourced national disease control programmes. Methods A cross-sectional qualitative descriptive study at 21 health centres in Uganda was undertaken in 2007 to elucidate the barriers and facilitators in the introduction of mRDTs as a new diagnostic technology at lower-level health facilities. Pre-tested interview questionnaires were administered through pre-structured patient exit interviews and semi-structured health worker interviews to gain an understanding of the response to this implementation. A conceptual framework on technology acceptance and use was adapted for this study and used to prepare the questionnaires. Thematic analysis was used to generate themes from the data. Results A total of 52 of 57 health workers (92% reported a belief that a positive mRDT result was true, although only 41 of 57 (64% believed that treatment with anti-malarials was justified for every positive mRDT case. Of the same health workers, only 49% believed that a negative mRDT result was truly negative. Factors linked to these findings were related to mRDT acceptance and use, including the design and characteristics of the device, availability and quality of mRDT ancillary supplies, health worker capacity to investigate febrile cases testing negative with the device and provide appropriate treatment, availability of effective malaria treatments, reliability of the health commodity supply chain, existing national

  15. Patient Experiences of Swallowing Exercises After Head and Neck Cancer: A Qualitative Study Examining Barriers and Facilitators Using Behaviour Change Theory.

    Science.gov (United States)

    Govender, Roganie; Wood, Caroline E; Taylor, Stuart A; Smith, Christina H; Barratt, Helen; Gardner, Benjamin

    2017-08-01

    Poor patient adherence to swallowing exercises is commonly reported in the dysphagia literature on patients treated for head and neck cancer. Establishing the effectiveness of exercise interventions for this population may be undermined by patient non-adherence. The purpose of this study was to explore the barriers and facilitators to exercise adherence from a patient perspective, and to determine the best strategies to reduce the barriers and enhance the facilitators. In-depth interviews were conducted on thirteen patients. We used a behaviour change framework and model [Theoretical domains framework and COM-B (Capability-opportunity-motivation-behaviour) model] to inform our interview schedule and structure our results, using a content analysis approach. The most frequent barrier identified was psychological capability. This was highlighted by patient reports of not clearly understanding reasons for the exercises, forgetting to do the exercises and not having a system to keep track. Other barriers included feeling overwhelmed by information at a difficult time (lack of automatic motivation) and pain and fatigue (lack of physical capability). Main facilitators included having social support from family and friends, the desire to prevent negative consequences such as long-term tube feeding (reflective motivation), having the skills to do the exercises (physical capability), having a routine or trigger and receiving feedback on the outcome of doing exercises (automatic motivation). Linking these findings back to the theoretical model allows for a more systematic selection of theory-based strategies that may enhance the design of future swallowing exercise interventions for patients with head and neck cancer.

  16. Overcoming Barriers to Experience Benefits: A Qualitative Analysis of Electronic Health Records and Health Information Exchange Implementation in Local Health Departments

    OpenAIRE

    Williams, Karmen S.; Shah, Gulzar H.; Leider, JP; Gupta, Akarti

    2017-01-01

    Introduction: Electronic Health Records (EHRs) and Health Information Exchanges (HIEs) are changing surveillance and analytic operations within local health departments (LHDs) across the United States. The objective of this study was to analyze the status, benefits, barriers, and ways of overcoming challenges in the implementation of EHRs and HIEs in LHDs.Methods: This study employed a mixed methods approach, first using the 2013 National Profile of LHDs survey to ascertain the status of EHR ...

  17. Barriers to the provision of high-quality palliative care for people with dementia in England: a qualitative study of professionals' experiences

    OpenAIRE

    Davies, Nathan; Maio, Laura; Vedavanam, Krish; Manthorpe, Jill; Vernooij-Dassen, Myrra; Iliffe, Steve

    2013-01-01

    Approaches to palliative care that were originally developed for people with cancer are now being adopted for people with dementia, as a response to many reports of poor-quality care for people with dementia at the end of life. This study explored perceived barriers to the delivery of high-quality palliative care for people with dementia using semi-structured interviews. Recordings were transcribed verbatim and analysed using thematic analysis with an inductive approach and a coding strategy....

  18. Barriers to leisure participation for people with dementia and their carers: An exploratory analysis of carer and people with dementia's experiences.

    Science.gov (United States)

    Innes, Anthea; Page, Stephen J; Cutler, Clare

    2016-11-01

    Leisure has emerged as a prominent research theme within the growing body of knowledge on dementia, with a focus on physical activity. Yet participation in any form of leisure presupposes an ability to freely choose to partake in activities and to negotiate one's way around key barriers. In the case of dementia, the ability to undertake leisure activities is subject to a greater range of barriers, structured in a hierarchical manner that contributes to social exclusion if not addressed. This study based on focus groups with people with dementia and their family members conducted in Dorset, UK illustrates a range of barriers to leisure participation. How to create or maintain leisure opportunities for those living with dementia where households affected by dementia do not adopt avoidance behaviour, compounding a sense of isolation and exclusion is a challenge. Leisure can be an important strategy framed as a form of resistance to the social disabilities experienced by those living with dementia and it is potentially isolating impact. © The Author(s) 2015.

  19. Barriers to the provision of high-quality palliative care for people with dementia in England: a qualitative study of professionals' experiences.

    Science.gov (United States)

    Davies, Nathan; Maio, Laura; Vedavanam, Krish; Manthorpe, Jill; Vernooij-Dassen, Myrra; Iliffe, Steve

    2014-07-01

    Approaches to palliative care that were originally developed for people with cancer are now being adopted for people with dementia, as a response to many reports of poor-quality care for people with dementia at the end of life. This study explored perceived barriers to the delivery of high-quality palliative care for people with dementia using semi-structured interviews. Recordings were transcribed verbatim and analysed using thematic analysis with an inductive approach and a coding strategy. To improve the trustworthiness of the analysis, independent reading and coding of the transcripts were undertaken, followed by discussions among the four researchers to reach agreement and consensus of the themes. Two group interviews (n = 7 and n = 6), 16 individual interviews and five interviews of pairs of professionals were conducted in 2011/2012 with participants from backgrounds in palliative care, dementia services, palliative care research and policy making. Four themes were identified as barriers to providing high-quality palliative care for people with dementia: (i) ambivalence towards the systematisation of palliative care; (ii) disconnection between services; (iii) different assumptions about training needs; and (iv) negotiation of risk. Understanding these barriers to providing high-quality palliative care for people with dementia could help in the development of a dementia-specific palliative care pathway. © 2013 The Authors. Health and Social Care in the Community published by John Wiley & Sons Ltd.

  20. Biographical Narratives of Encounter: The Significance of Mobility and Emplacement in Shaping Attitudes towards Difference

    Science.gov (United States)

    Sadgrove, Joanna

    2014-01-01

    This paper is located within work in urban studies about the significance of contact with difference as a means for reducing prejudice and achieving social change. Recent approaches, influenced by theories of affect, have emphasised non-conscious everyday negotiations of difference in the city. In this paper it is argued that such approaches lose sight of the significance of the subject: of the reflective judgements of ‘others’ made by individuals; of our ability to make decisions around the control of our feelings and identifications; and of the significance of personal pasts and collective histories in shaping the ways we perceive and react to encounters. Rather, this paper uses a biographical approach focusing on interviewees’ narratives of encounter. Through its attention to processes of mobility and emplacement, it contributes to debates about when contact with difference matters by highlighting the importance of everyday social normativities in the production of moral dispositions. PMID:26300566

  1. The offshore disposal of radioactive waste by drilled emplacement: A feasibility study

    International Nuclear Information System (INIS)

    Bury, M.R.C.

    1985-01-01

    This book is a report, based on a study by Taylor Woodrow Construction Limited, on the overall feasibility of the disposal of high-level radioactive waste in boreholes drilled deep into the ocean bed. The work comprises an engineering appraisal of the disposal process with a view to establishing technical and operational feasibility and providing overall cost information to enable an economic assessment to be made. Contents: Summary report; Reference criteria; Drilling operation; Transfer of radioactive waste, personnel and other supplies; Handling of radioactive waste on board; Lowering strings of canisters; Emplacement and backfilling of canisters; Preliminary design of marine platform; Retrieval of flasks or canisters lost or misplaced; Variations to the features of the lowering system; Logistics of the operation; Construction cost estimate; Operational costs; Appendix

  2. Revisiting Emplacement Depths of the Fine Gold Intrusive Suite, West-Central Sierra Nevada

    Science.gov (United States)

    Head, D.; Lackey, J.

    2013-12-01

    The Fine Gold Intrusive Suite (FGIS) is a large intrusive complex in the west central portion of the Sierra Nevada Batholith. Portions of the Sierra Nevada Batholith have been well studied for plutonic pressure and crystallization histories (e.g., Ague and Brimhall, 1988, GSAB), whereas the regional depth of emplacement of the FGIS is not well characterized, and in previous work pressure estimates were not corrected for crystallization temperatures. An accurate sense of barometric gradient in the FGIS is important to evaluate the roles of pre-batholithic structural breaks in controlling magma emplacement levels, and also to reconstruct erosional levels within the Sierra Nevada as a whole. In this study, samples from the FGIS, all from the Bass Lake Tonalite, were petrographically characterized to identify those samples that contain mineral assemblage and crystallization textures appropriate for application of the Aluminum-in-Hornblende barometer of Hammarstrom and Zen (1986) re-calibrated by Anderson and Smith (1995). Analysis of these samples and use of the barometer results in both pressure and temperature of crystallization. FGIS amphiboles are typical magnesio-hornblende on average: K0.2Na0.1Ca1.8[Mg2.4(Al,Fe3+)(0.2-0.6)]Si6.7Ti0.1Al1.3O22(OH)2. Plagioclase compositional ranges are Ab(54-69)An(30-45)Or(0-1). Bass Lake Tonalite data of Ague and Brimhall (1988) were re-calculated for typical plagioclase composition in the Bass Lake Tonalite (Ab62An37Or1), yielding slightly higher crystallization pressures (3.3 to 5.8 kbar) than the original range (2.4 to 4.5 kbar). New FGIS crystallization pressures of 2.6 to 3.5 kbar match the recalculated data well, thus providing larger coverage for estimates of emplacement depth. Apparent temperatures from adjacent amphibole and plagioclase rims were found to be 691 to 767°C. When all barometric data are considered together, and uncertainties of the calibration are factored in, we find that FGIS crystallization pressures

  3. Homeless Blogs as Travelogues. Travel as a Struggle for Recognition and Emplacement

    Directory of Open Access Journals (Sweden)

    Halina Gąsiorowska

    2017-07-01

    Full Text Available Applying Clifford’s broad concept of travel, I discuss American homeless blogs as autobiographical travel writing serving the struggle for recognition of the street people. The analysed travelogues are hitchhiker Ruth Rader’s Ruthie in the Sky blog and self-made woman Brianna Karp’s Girl’s Guide to Homelessness – a memoir published on the basis of the blog bearing the same title. In the travelogues I analyse the characteristic features of a personal travel writing: travel of the self, advice for future travelers, geographic information and portrayal of society in which the travel is undertaken. I claim that homeless bloggers recounting their stories of otherness and displacement in the US contribute to (reconstructing American cultural identity their personal Self, just like many other American travelers before. Additionally, homeless blogging about homelessness is shown as the process of emplacement (Casey – the bloggers’ attempt of making themselves at home in the world.

  4. Structural Analysis of Silicic Lavas Reveals the Importance of Endogenous Flow During Emplacement

    Science.gov (United States)

    Andrews, G. D.; Martens, A.; Isom, S.; Maxwell, A.; Brown, S. R.

    2017-12-01

    Recent observations of silicic lava flows in Chile strongly suggest sustained, endogeneous flow beneath an insulating carapace, where the flow advances through breakouts at the flow margin. New mapping of vertical exposures around the margin of Obsidian Dome, California, has identified discreet lobe structures in cross-section, suggesting that flow-front breakouts occured there during emplacement. The flow lobes are identified through structural measurements of flow-banding orientation and the stretching directions of vesicles. Newly acquired lidar of the Inyo Domes, including Obsidian Dome, is being analyzed to better understand the patterns of folding on the upper surface of the lavas, and to test for fold vergence patterns that may distinguish between endogenous and exogenous flow.

  5. Additive Construction with Mobile Emplacement (ACME) / Automated Construction of Expeditionary Structures (ACES) Materials Delivery System (MDS)

    Science.gov (United States)

    Mueller, R. P.; Townsend, I. I.; Tamasy, G. J.; Evers, C. J.; Sibille, L. J.; Edmunson, J. E.; Fiske, M. R.; Fikes, J. C.; Case, M.

    2018-01-01

    The purpose of the Automated Construction of Expeditionary Structures, Phase 3 (ACES 3) project is to incorporate the Liquid Goods Delivery System (LGDS) into the Dry Goods Delivery System (DGDS) structure to create an integrated and automated Materials Delivery System (MDS) for 3D printing structures with ordinary Portland cement (OPC) concrete. ACES 3 is a prototype for 3-D printing barracks for soldiers in forward bases, here on Earth. The LGDS supports ACES 3 by storing liquid materials, mixing recipe batches of liquid materials, and working with the Dry Goods Feed System (DGFS) previously developed for ACES 2, combining the materials that are eventually extruded out of the print nozzle. Automated Construction of Expeditionary Structures, Phase 3 (ACES 3) is a project led by the US Army Corps of Engineers (USACE) and supported by NASA. The equivalent 3D printing system for construction in space is designated Additive Construction with Mobile Emplacement (ACME) by NASA.

  6. The Sonju Lake layered intrusion, northeast Minnesota: Internal structure and emplacement history inferred from magnetic fabrics

    Science.gov (United States)

    Maes, S.M.; Tikoff, B.; Ferre, E.C.; Brown, P.E.; Miller, J.D.

    2007-01-01

    The Sonju Lake intrusion (SLI), in northeastern Minnesota, is a layered mafic complex of Keweenawan age (1096.1 ?? 0.8 Ma) related to the Midcontinent rift. The cumulate paragenesis of the intrusion is recognized as broadly similar to the Skaergaard intrusion, a classic example of closed-system differentiation of a tholeiitic mafic magma. The SLI represents nearly closed-system differentiation through bottom-up fractional crystallization. Geochemical studies have identified the presence of a stratabound, 50-100 m thick zone anomalously enriched in Au + PGE. Similar to the PGE reefs of the Skaergaard intrusion, this PGE-enriched zone is hosted within oxide gabbro cumulates, about two-third of the way up from the base of the intrusion. We present a petrofabric study using the anisotropy of magnetic susceptibility (AMS) to investigate the emplacement and flow patterns within the Sonju Lake intrusion. Petrographic and electron microprobe studies, combined with AMS and hysteresis measurements indicate the primary source of the magnetic signal is pseudo-single domain (PSD) magnetite or titanomagnetite. Low field AMS was measured at 32 sites within the Sonju Lake intrusion, which provided information about primary igneous fabrics. The magnetic fabrics in the layered series of the Sonju Lake intrusion are consistent with sub-horizontal to inclined emplacement of the intrusion and show evidence that the cumulate layers were deposited in a dynamic environment. Well-aligned magnetic lineations, consistently plunging shallowly toward the southwest, indicate the source of the magma is a vertical sill-like feeder, presumably located beneath the Finland granite. The Finland granite acted as a density trap for the Sonju Lake magmas, forcing lateral flow of magma to the northeast. The strongly oblate magnetic shape fabrics indicate the shallowly dipping planar fabrics were enhanced by compaction of the crystal mush. ?? 2007 Elsevier B.V. All rights reserved.

  7. Emplacement and Deformation of Mesozoic Gabbros of the High Atlas (Morocco): Paleomagnetism and Magnetic Fabrics

    Science.gov (United States)

    Calvín, P.; Ruiz-Martínez, V. C.; Villalaín, J. J.; Casas-Sainz, A. M.; Moussaid, B.

    2017-12-01

    A paleomagnetic and magnetic fabric study is performed in Upper Jurassic gabbros of the central High Atlas (Morocco). These gabbros were emplaced in the core of preexisting structures developed during the extensional stage and linked to basement faults. These structures were reactivated as anticlines during the Cenozoic compressional inversion. Gabbros from 19 out of the 33 sampled sites show a stable characteristic magnetization, carried by magnetite, which has been interpreted as a primary component. This component shows an important dispersion due to postemplacement tectonic movements. The absence of paleoposition markers in these igneous rocks precludes direct restorations. A novel approach analyzing the orientation of the primary magnetization is used here to restore the magmatic bodies and to understand the deformational history recorded by these rocks. Paleomagnetic vectors are distributed along small circles with horizontal axes, indicating horizontal axis rotations of the gabbro bodies. These rotations are higher when the ratio between shales and gabbros in the core of the anticlines increases. Due to the uncertainties inherent to this work (the igneous bodies recording strong rotations), interpretations must be qualitative. The magnetic fabric is carried by ferromagnetic (s.s.) minerals mimicking the magmatic fabric. Anisotropy of magnetic susceptibility (AMS) axes, using the rotation routine inferred from paleomagnetic results, result in more tightly clustered magnetic lineations, which also become horizontal and are considered in terms of magma flow trend during its emplacement: NW-SE (parallel to the general extensional direction) in the western sector and NE-SW (parallel to the main faults) in the easternmost structures.

  8. The emplacement dynamics of pumice lobes ascertained from morphology and granulometry: Examples from the 1993 deposits at Lascar Volcano, Chile

    Science.gov (United States)

    Whelley, Patrick L.; Calder, Eliza S.; Wooller, Luke

    2017-08-01

    The work presented here focuses on lobe shapes and clast populations within lobate termini of the 1993 pumice flow deposits at Lascar Volcano, Chile. A new method to analyze a coarse-tail grain size population with field photographs is presented. Using this method, > 33,000 (> 0.5 cm) clasts from the pumice lobes of the 1993 pumice flow deposits were measured at 36 sites, and the resultant grain size distributions were then related to lobe morphology. Lobe margins (i.e., levees, clefts, and snouts) were found to contain significantly larger pumice clasts and be more poorly sorted than lobe central channels (i.e., locations away from the margins). Previous laboratory experiments suggest lobe margins form by the floatation and deflection of larger clasts to the margins of an advancing flow lobe. Results here indicate that the same sorting process efficiently segregates clasts into two flow regimes: 1) a mobile central channel depleted in coarse clasts, and 2) friction-dominated margins enriched in clasts ≥ 15 cm. The lobe margins, 60% enriched in larger particles with matrix < 20%, slow and frictionally freeze from the base up and before the material in the central channel stops flowing. The advancing pumice lobes finally stop when the margins reach 12 clasts thick and the central channel has insufficient mass flux or momentum to break through or over-top the static margins. These processes form a unique lobe and channel morphology deposit that is diagnostic of granular flow and typical of small to intermediate volume pumice flow emplacement.

  9. Fish barriers

    International Nuclear Information System (INIS)

    Larsson, Mats

    1992-11-01

    In addition to literature reviews laboratory experiments with both strobe light and different kinds of sound stimuli were carried out. In the experiments silver eel, brown trout, arctic char and salmon smolts were tested. The experiments showed that in darkness silver eel avoided strobe light with intensities between 0.4 and 8.7 lux with 80-90% avoidance in 8.7 lux. The avoidance reactions decreased when background light was raised to 9 lux. Brown trout did not show as strong avoidance reactions possibly due to aggressive behaviour between different individuals of brown trout. The avoidance reaction was however more pronounced in dim background lift with an intensity of 5 lux than in darkness. The experiments also showed that the avoidance reactions started within a few seconds after exposure to strobe light. The frequencies 6.0 and 15 Hz were more effective as triggers of avoidance reactions than were the frequencies 2.1 and 160 Hz. Arctic char did not show any avoidance reactions to strobe light. It was actually attracted to strobe light with the frequency 160 Hz in total darkness and indifferent in dim background light 10 lux. Experiments in running water also showed that salmon smolts could be diverted from an area exposed to strobe light with the frequency 15.0 Hz. The effect was more pronounced in darkness than in dim background light and also more pronounced when water current was 20 cm/s than when it was 40 or 60 cm/s. Experiments to test the avoidance reactions to sound was also performed. The evaluation of these results where however complicated by the fact that the fishes swam rapidly to and fro in the experimental chamber and thus by pure chance very frequently were close to the sound generator

  10. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

  11. Granitic magma emplacement and deformation during early-orogenic syn-convergent transtension: The Stare Sedlo complex, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Tomek, Filip; Žák, J.; Chadima, Martin

    2015-01-01

    Roč. 87, JUL (2015), s. 50-66 ISSN 0264-3707 Institutional support: RVO:67985831 Keywords : anisotropy of magnetic susceptibility (AMS) * Bohemian Massif * pluton emplacement * granite * transtension * Variscan orogeny Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.926, year: 2015

  12. Simultaneous batholith emplacement, terrane/continent collision, and oroclinal bending in the Blue Mountains Province, North American Cordillera

    Czech Academy of Sciences Publication Activity Database

    Žák, J.; Verner, K.; Tomek, Filip; Holub, F. V.; Johnson, K.; Schwartz, J. J.

    2015-01-01

    Roč. 34, č. 6 (2015), s. 1107-1128 ISSN 0278-7407 Institutional support: RVO:67985831 Keywords : anisotropy of magnetic susceptibility (AMS) * North American Cordillera * orocline * pluton emplacement * terrane accretion * terrane/continent collision Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.750, year: 2015

  13. AN EVALUATION TO IDENTIFY THE BARRIERS TO THE FEASIBILITY OF URBAN DEVELOPMENT PLANS: FIVE DECADES OF EXPERIENCE IN URBAN PLANNING IN IRAN

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Maghsoodi Tilaki

    2014-01-01

    Full Text Available The rapid urbanization in many developing countries has indicat ed several challenges in different aspects. This is due t o inefficient urban planning ap proaches towards managing the development process. Similar to many other developing count ries, Iran has experienced rapid urbanization in recent decades. Although over the last few decades, urban planning processes have been applied to develop Iranian c ities, urban planning has failed to tackle the challenges facing the cities. This paper s eeks to identify the barriers that have prevented Iranian c ities from achieving the goals of urban planning. The purpose of this paper is to provide a comprehensive review of the curre nt literature on the concept of urban planning and to assess the urban development plan proc ess in Iranian cities. The required data were collected through a review of international theoretical studies, Iranian experimental research and governmental reports. The findings of this study reveal five major barriers to the feasibility of the urban planning process , including the urban plans context, structure of urban pla nning, related law and regulatio ns, public participation, and financial resources.

  14. Breaching barriers to collaboration in public spaces

    DEFF Research Database (Denmark)

    Heinemann, Trine; Mitchell, Robb

    2014-01-01

    Technology provoking disparate individuals to collaborate or share experiences in the public space faces a difficult barrier, namely the ordinary social order of urban places. We employed the notion of the breaching experiment to explore how this barrier might be overcome. We analyse responses...... of life in public spaces. Arising from this, we argue for the importance of qualities such as availability, facilitation, perspicuous settings, and perspicuous participants to encourage and support co-located strangers to collaborate and share experiences....

  15. Photogrammetric and Global Positioning System Measurements of Active Pahoehoe Lava Lobe Emplacement on Kilauea, Hawaii

    Science.gov (United States)

    Hamilton, Christopher W.; Glaze, Lori S.; James, Mike R.; Baloga, Stephen M.; Fagents, Sarah A.

    2012-01-01

    Basalt is the most common rock type on the surface of terrestrial bodies throughout the solar system and -- by total volume and areal coverage -- pahoehoe flows are the most abundant form of basaltic lava in subaerial and submarine environments on Earth. A detailed understanding of pahoehoe emplacement processes is necessary for developing accurate models of flow field development, assessing hazards associated with active lava flows, and interpreting the significance of lava flow morphology on Earth and other planetary bodies. Here, we examine the active emplacement of pahoehoe lobes along the margins of the Hook Flow from Pu'u 'O'o on Kilauea, Hawaii. Topographic data were acquired between 21 and 23 February 2006 using stereo-imaging and differential global positing system (DGPS) measurements. During this time, the average discharge rate for the Hook Flow was 0.01-0.05 cubic m/s. Using stereogrammetric point clouds and interpolated digital terrain models (DTMs), active flow fronts were digitized at 1 minute intervals. These areal spreading maps show that the lava lobe grew by a series of breakouts tha t broadly fit into two categories: narrow (0.2-0.6 m-wide) toes that grew preferentially down-slope, and broad (1.4-3.5 m-wide) breakouts that formed along the sides of the lobe, nearly perpendicular to the down-flow axis. These lobes inflated to half of their final thickness within approx 5 minutes, with a rate of inflation that generally deceased with time. Through a combination of down-slope and cross-slope breakouts, lobes developed a parabolic cross-sectional shape within tens of minutes. We also observed that while the average local discharge rate for the lobe was generally constant at 0.0064 +/- 0.0019 cubic m/s, there was a 2 to 6 fold increase in the areal coverage rate every 4.1 +/- 0.6 minutes. We attribute this periodicity to the time required for the dynamic pressurization of the liquid core of the lava lobe to exceed the cooling-induced strength of the

  16. 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

  17. 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

  18. 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.

  19. Explosive ordinance disposal technology demonstration using the telerobotic small emplacement excavator

    Energy Technology Data Exchange (ETDEWEB)

    Burks, B.L.; Killough, S.M.; Thompson, D.H.; Dinkins, M.A. [Oak Ridge National Lab., TN (United States). Robotics & Process Systems Div.

    1994-06-01

    The small emplacement excavator (SEE) is a ruggedized military vehicle with backhoe and front loader used by the US Army for explosive ordinance disposal (EOD), combat engineer, and general utility excavation activities. In order to evaluate the feasibility of removing personnel from the vehicle during the high risk EOD excavation tasks a development and demonstration project was initiated to evaluate performance capabilities of the SEE under telerobotic control. This feasibility study was performed at the request of the Ordinance Missile and Munitions Center and School (OMMCS) at the Redstone Arsenal to help define requirements for further joint service development activities. Development of a telerobotic SEE (TSEE) was performed by the Oak Ridge National Laboratory (ORNL) in a project funded jointly by the US Army Project Manager for Ammunition Logistics (PM-AMMOLOG) and the Department of Energy (DOE) Office of Technology Development (OTD) Robotics Technology Development Program (RTDP). A technology demonstration of the TSEE was conducted at McKinley Range, Redstone Arsenal, Huntsville, Alabama, on September 13--17, 1993. The primary objective of the demonstration was to evaluate and demonstrate the feasibility of remote EOD. During the demonstration, approximately 40 EOD specialists were instructed on telerobotic operation of the TSEE and then were asked to complete a series of simulated EOD tasks. Upon completion of the tasks, participants completed an evaluation of the system including human factors performance data.

  20. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-08-01

    The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste.

  1. Emplacement dynamics and hydrothermal alteration of the Atengo ignimbrite, southern Sierra Madre Occidental, northwestern Mexico

    Science.gov (United States)

    Agarwal, Amar; Alva-Valdivia, L. M.; Rivas-Sánchez, M. L.; Herrero-Bervera, E.; Urrutia-Fucugauchi, J.; Espejel-García, V.

    2017-12-01

    The Sierra Madre Occidental is a thick continental arc related to the subduction of the Farallon plate beneath North America resulting in a very intense and widespread Cretaceous to Cenozoic magmatic and tectonic activity. The 28 My old Atengo ignimbrite outcrops in the southern Sierra Madre Occidental, northwestern Mexico. From 12 sites that belong to various pyroclastic and lava flows emplaced during two pulses in the Oligocene (ca. 32-28 Ma) and Early Miocene (ca. 24-20 Ma), 97 rock specimens were drilled. The mineralogical and rock magnetic properties of the Atengo ignimbrite are compared with the surrounding volcanic rocks to identify the eruption mechanism, and with the El Castillo Ignimbrite, Veracruz, Mexico, to understand the depositional conditions. The comparisons reveal that the Atengo ignimbrite erupted from a single source, but less violently than the El Castillo ignimbrite, and cooled rapidly, inhibiting the formation of subhedral grains. The source of the Atengo Ignimbrite was a Plinian-type eruption, and the characteristic mineralogical and textural properties of each flow are related to different stages of the Plinian-type eruption. Further more, hydrothermal fluids were active during the last stages of volcanism, and caused moderate to intense alteration, especially in the ignimbrites, where high permeability aided the movement of hydrothermal fluids.

  2. Large-scale sill emplacement in Brazil as a trigger for the end-Triassic crisis.

    Science.gov (United States)

    Heimdal, Thea H; Svensen, Henrik H; Ramezani, Jahandar; Iyer, Karthik; Pereira, Egberto; Rodrigues, René; Jones, Morgan T; Callegaro, Sara

    2018-01-09

    The end-Triassic is characterized by one of the largest mass extinctions in the Phanerozoic, coinciding with major carbon cycle perturbations and global warming. It has been suggested that the environmental crisis is linked to widespread sill intrusions during magmatism associated with the Central Atlantic Magmatic Province (CAMP). Sub-volcanic sills are abundant in two of the largest onshore sedimentary basins in Brazil, the Amazonas and Solimões basins, where they comprise up to 20% of the stratigraphy. These basins contain extensive deposits of carbonate and evaporite, in addition to organic-rich shales and major hydrocarbon reservoirs. Here we show that large scale volatile generation followed sill emplacement in these lithologies. Thermal modeling demonstrates that contact metamorphism in the two basins could have generated 88,000 Gt CO 2 . In order to constrain the timing of gas generation, zircon from two sills has been dated by the U-Pb CA-ID-TIMS method, resulting in 206 Pb/ 238 U dates of 201.477 ± 0.062 Ma and 201.470 ± 0.089 Ma. Our findings demonstrate synchronicity between the intrusive phase and the end-Triassic mass extinction, and provide a quantified degassing scenario for one of the most dramatic time periods in the history of Earth.

  3. Explosive eruptive history of Pantelleria, Italy: Repeated caldera collapse and ignimbrite emplacement at a peralkaline volcano

    Science.gov (United States)

    Jordan, Nina J.; Rotolo, Silvio G.; Williams, Rebecca; Speranza, Fabio; McIntosh, William C.; Branney, Michael J.; Scaillet, Stéphane

    2018-01-01

    A new, pre-Green Tuff (46 ka) volcanic stratigraphy is presented for the peralkaline Pantelleria Volcano, Italy. New 40Ar/39Ar and paleomagnetic data are combined with detailed field studies to develop a comprehensive stratigraphic reconstruction of the island. We find that the pre-46 ka succession is characterised by eight silica-rich peralkaline (trachyte to pantellerite) ignimbrites, many of which blanketed the entire island. The ignimbrites are typically welded to rheomorphic, and are commonly associated with lithic breccias and/or pumice deposits. They record sustained radial pyroclastic density currents fed by low pyroclastic fountains. The onset of ignimbrite emplacement is typically preceded (more rarely followed) by pumice fallout with limited dispersal, and some eruptions lack any associated pumice fall deposit, suggesting the absence of tall eruption columns. Particular attention is given to the correlation of well-developed lithic breccias in the ignimbrites, interpreted as probable tracers of caldera collapses. They record as many as five caldera collapse events, in contrast to the two events reported to date. Inter-ignimbrite periods are characterised by explosive and effusive eruptions with limited dispersal, such as small pumice cones, as well as pedogenesis. These periods have similar characteristics as the current post-Green Tuff activity on the island, and, while not imminent, it is reasonable to postulate the occurrence of another ignimbrite-forming eruption sometime in the future.

  4. InSAR observations of ground surface deformation and lava flow emplacement at Pacaya volcano, Guatemala

    Science.gov (United States)

    Schaefer, L. N.; Lu, Z.; Oommen, T.

    2015-12-01

    Pacaya volcano is a persistently active basaltic cone complex located in the Central American Volcanic Arc in Guatemala. In May, 2010, violent VEI-3 eruptions caused significant topographic changes to the edifice, including the dispersion of ~20 cm of tephra and ash on the cone, the emplacement of a ~5.4 km long lava flow, and 3 m of co-eruptive movement of the southwest flank. For this study, Interferometric Synthetic Aperture Radar (InSAR) images (interferograms) processed from both spaceborne Advanced Land Observing Satellite (ALOS) and aerial Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data were used to measure post-eruptive deformation events. Interferograms suggest four distinct deformation processes after the May 2010 eruption: (1) magma intrusion near the vents of the 2010 lava flow; (2) subsidence of the 2010 lava flow; (3) slow deflation of an elongated magma source near the summit, and; (4) settlement of the material involved in the co-eruptive slope movement. Our results provide insights into Pacaya's complex magmatic plumbing system and the postemplacement behavior of lava flows. The detection of several different deformation events emphasizes the utility of measuring volcanic deformation using high-resolution remote sensing techniques with broad spatial coverage.

  5. Water and contaminant movement: migration barriers

    International Nuclear Information System (INIS)

    Lane, L.J.; Nyhan, J.W.

    1984-11-01

    Migration barriers are used in shallow land burial facilities to slow or stop the movement of water and contaminants and are discussed here as a single component embedded in a complex environmental system. Analytical solutions to solute transport equations are used to approximate the behavior of migration barriers and to derive design criteria for control of subsurface water and contaminant migration. Various types of migration barriers are compared and design recommendations are made for shallow land burial trench caps and liners. Needed improvements and suggested field experiments for future designs of migration barriers are then discussed relative to the management of low-level radioactive wastes

  6. Quarter-scale modeling of room convergence effects on CH [contact-handled] TRU drum waste emplacements using WIPP [Waste Isolation Pilot Plant] reference design geometries

    International Nuclear Information System (INIS)

    VandeKraats, J.

    1987-11-01

    This study investigates the effect of horizontal room convergence on CH waste packages emplaced in the WIPP Reference Design geometry (rooms 13 feet high by 33 feet wide, with minus 3/8 inch screened backfill emplaced over and around the waste packages) as a function of time. Based on two tests, predictions were made with regard to full-scale 6-packs emplaced in the Reference Design geometry. These are that load will be transmitted completely through the stack within the first five years after waste emplacement and all drums in all 6-packs will be affected; that virtually all drums will show some deformation eight years after emplacement; that some drums may breach before the eighth year after emplacement has elapsed; and that based on criteria developed during testing, it is predicted that 1% of the drums emplaced will be breached after 8 years and, after 15 years, approximately 12% of the drums are predicted to be breached. 8 refs., 41 figs., 3 tabs

  7. Non-linear, non-monotonic effect of nano-scale roughness on particle deposition in absence of an energy barrier: Experiments and modeling

    Science.gov (United States)

    Jin, Chao; Glawdel, Tomasz; Ren, Carolyn L.; Emelko, Monica B.

    2015-12-01

    Deposition of colloidal- and nano-scale particles on surfaces is critical to numerous natural and engineered environmental, health, and industrial applications ranging from drinking water treatment to semi-conductor manufacturing. Nano-scale surface roughness-induced hydrodynamic impacts on particle deposition were evaluated in the absence of an energy barrier to deposition in a parallel plate system. A non-linear, non-monotonic relationship between deposition surface roughness and particle deposition flux was observed and a critical roughness size associated with minimum deposition flux or “sag effect” was identified. This effect was more significant for nanoparticles (work provides 1) a first comprehensive framework for describing the hydrodynamic impacts of nano-scale surface roughness on particle deposition by unifying hydrodynamic forces (using the most current approaches for describing flow field profiles and hydrodynamic retardation effects) with appropriately modified expressions for DLVO interaction energies, and gravity forces in one model and 2) a foundation for further describing the impacts of more complicated scales of deposition surface roughness on particle deposition.

  8. Smart parking barrier

    KAUST Repository

    Alharbi, Abdulrazaq M.

    2016-05-06

    Various methods and systems are provided for smart parking barriers. In one example, among others, a smart parking barrier system includes a movable parking barrier located at one end of a parking space, a barrier drive configured to control positioning of the movable parking barrier, and a parking controller configured to initiate movement of the parking barrier, via the barrier drive. The movable parking barrier can be positioned between a first position that restricts access to the parking space and a second position that allows access to the parking space. The parking controller can initiate movement of the movable parking barrier in response to a positive identification of an individual allowed to use the parking space. The parking controller can identify the individual through, e.g., a RFID tag, a mobile device (e.g., a remote control, smartphone, tablet, etc.), an access card, biometric information, or other appropriate identifier.

  9. Geology and tectonic magmatic of emplacement of a longitudinal dyke swarm of Nico Perez(Minas) URUGUAY

    International Nuclear Information System (INIS)

    Gonzalez, P.; Poire, D.; Canalicchio, J.; Garcia Repetto, F.

    2004-01-01

    The Mina Verdun Group (Precambrian) was deposited prior to the subvolcanic emplacement of a longitudinal dyke swarm of basaltic to andesitic composition (Minas Subvolcanic Swarm of the Mina Verdun quarry - Nico Perez Terrane, Minas, Uruguay). The swarm and its country rocks predated a tectono-metamorphic event that produced fragileductile shear zones associated with very low- to low-grade dislocation metamorphism. We interpreted a K-Ar whole rock datum of 485,2 ± 12,5 Ma (andesitic dyke) as a minimum cooling age in relation with late- to post-swarm emplacement deuteric alteration stage. Another K-Ar whole rock datum of 108,5 ± 2,9 Ma on a basaltic dyke was assumed here as a degasification stage, while its geological meaning is still matter of debate. The Minas Subvolcanic Dyke Swarm was intruded at high crustal levels, suggesting that the Minas region was affected by a period of extensional tectonics [es

  10. Operational procedures for receiving, packaging, emplacing, and retrieving high-level and transuranic waste in a geologic repository in TUFF

    International Nuclear Information System (INIS)

    Dennis, A.W.; Mulkin, R.

    1984-01-01

    The Nevada Nuclear Waste Storage Investigations Project, directed by the Nevada Operations Office of the Department of Energy, is currently developing conceptual designs for a commercial nuclear waste repository. In this paper, the preliminary repository operating plans are identified and the proposed repository waste inventory is discussed. The receipt rates for truck and rail car shipments of waste are determined as are the required repository waste emplacement rates

  11. An AMS study of magma transport and emplacement mechanisms in mafic dykes from the Etendeka Province, Namibia

    Science.gov (United States)

    Wiegand, Miriam; Trumbull, Robert B.; Kontny, Agnes; Greiling, Reinhard O.

    2017-10-01

    The Henties Bay Outjo dyke swarm (HOD) in NW Namibia is part of the early Cretaceous Paraná-Etendeka Large Igneous Province. The dykes are dominantly doleritic, compositionally equivalent to the erupted lava series and thus the HOD provides a look at the feeder systems of a flood basalt province. The subvertical dykes mostly strike NE-SW and minor NW-SE, parallel or perpendicular to the Damara Belt in which they intruded. We present a magnetic fabric study using the anisotropies of low-field magnetic susceptibility (AMS) and of anhysteretic remanent magnetization (AARM) with the aim to derive magma flow directions and better constrain emplacement mechanisms within the dyke swarm. Magnetic susceptibility and its anisotropy in the dykes is mainly controlled by distribution anisotropy of titanomagnetite that mimics the flow-oriented silicate fabric. The anisotropy is low in most samples, supporting a magmatic origin. In 66 of 110 investigated samples the AMS fabric is ;normal;, with the κmax axis (inferred flow orientation) within the dyke plane. Most samples yielded vertical to subvertical flow orientations regardless of location near or distant from the former rifted margin. The ;anomalous; magnetic fabrics, where κmax is inclined to the dyke plane, are attributed to two mechanisms. One is the single-domain effect of titanomagnetite, which was found by unequal orientations of AMS and AARM fabrics. The other case anomalous fabric is rotation of the AMS axes by shear within the magma, producing symmetric imbrication of AMS fabric on opposite dyke walls; or more commonly, asymmetric magnetic fabrics, which we relate to tectonic shear at the dyke walls during emplacement. Field support for syn-emplacement shear is given by dyke segmentation geometries including locally curved segment tips, en-echelon arrangements and left/right-stepping displacements. Regionally, syn-emplacement shear is consistent with the observed reactivation during Gondwana breakup of

  12. Emplacement dynamics of phonolite magma into maar-diatreme structures - Correlation of field, thermal modeling and AMS analogue modeling data

    Czech Academy of Sciences Publication Activity Database

    Závada, Prokop; Dědeček, Petr; Mach, K.; Lexa, O.; Potužák, M.

    2011-01-01

    Roč. 201, č. 1-4 (2011), s. 210-226 ISSN 0377-0273 R&D Projects: GA MŠk ME09011; GA AV ČR KJB301110703 Institutional research plan: CEZ:AV0Z30120515 Keywords : phonolite * maar-diatreme * magma emplacement dynamics * thermal modeling * AMS analogue modeling * cavitation Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.978, year: 2011

  13. Granitoid emplacement during syn-convergent transtension: An example from the Huamenlou pluton in North Qinling, central China

    Directory of Open Access Journals (Sweden)

    Yang Li

    2018-01-01

    Full Text Available The Huamenlou pluton, is an elongated granite intrusion with high aspect ratio, emplaced within the southern margin of the North Qinling (central China. Here we investigate this pluton through multiple techniques including the fabric study, microstructural observation and zircon geochronology. Our zircon U–Pb data confirm that the granite crystallized at ca. 462 Ma which is consistent with the ages of other linear plutons in North Qinling. Microstructural observations of the Huamenlou granites illustrate that the pluton has undergone superimposed deformation during its emplacement, from magmatic to high-temperature solid state conditions. The internal fabric obtained by anisotropy of magnetic susceptibility (AMS and shape preferred orientation (SPO show similar results. The fabrics are relatively concordant and generally vary from NE–SW to NEE–SWW which are roughly oblique to the trend of the pluton elongation and the regional structures. Meanwhile, scalar parameters reflect two completely different strain regimes for the pluton and its host rocks, i.e., the fabrics within host rocks are mainly oblate while the central part of the intrusion displays mainly prolate fabrics. It is inferred that the structural pattern recorded in this pluton was caused by local dextral transtension in consequence of oblique convergence between the South and North China Blocks. We propose that the local transtension in convergence setting probably evolved from vertical extrusion tectonics that provided room for the magma emplacement and imparted prolate fabrics in the Huamenlou pluton.

  14. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    Science.gov (United States)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  15. Magnetic fabrics in characterization of magma emplacement and tectonic evolution of the Moyar Shear Zone, South India

    Directory of Open Access Journals (Sweden)

    P. Pratheesh

    2013-01-01

    Full Text Available The Moyar Shear Zone (MSZ of the South Indian granulite terrain hosts a prominent syenite pluton (∼560 Ma and associated NW-SE to NE-SW trending mafic dyke swarm (∼65 Ma and 95 Ma. Preliminary magnetic fabric studies in the mafic dykes, using Anisotropy of Magnetic Susceptibly (AMS studies at low-field, indicate successive emplacement and variable magma flow direction. Magnetic lineation and foliation in these dykes are identical to the mesoscopic fabrics in MSZ mylonites, indicating shear zone guided emplacement. Spatial distribution of magnetic lineation in the dykes suggests a common conduit from which the source magma has been migrated. The magnetic foliation trajectories have a sigmoidal shape to the north of the pluton and curve into the MSZ suggesting dextral sense of shear. Identical fabric conditions for magnetic fabrics in the syenite pluton and measured field fabrics in mylonite indicate syntectonic emplacement along the Proterozoic crustal scale dextral shear zone with repeated reactivation history.

  16. Tracking lava flow emplacement on the east rift zone of Kilauea, Hawai’i with synthetic aperture radar (SAR) coherence

    Science.gov (United States)

    Dietterich, Hannah R.; Poland, Michael P.; Schmidt, David; Cashman, Katharine V.; Sherrod, David R.; Espinosa, Arkin Tapia

    2012-01-01

    Lava flow mapping is both an essential component of volcano monitoring and a valuable tool for investigating lava flow behavior. Although maps are traditionally created through field surveys, remote sensing allows an extraordinary view of active lava flows while avoiding the difficulties of mapping on location. Synthetic aperture radar (SAR) imagery, in particular, can detect changes in a flow field by comparing two images collected at different times with SAR coherence. New lava flows radically alter the scattering properties of the surface, making the radar signal decorrelated in SAR coherence images. We describe a new technique, SAR Coherence Mapping (SCM), to map lava flows automatically from coherence images independent of look angle or satellite path. We use this approach to map lava flow emplacement during the Pu‘u ‘Ō‘ō-Kupaianaha eruption at Kīlauea, Hawai‘i. The resulting flow maps correspond well with field mapping and better resolve the internal structure of surface flows, as well as the locations of active flow paths. However, the SCM technique is only moderately successful at mapping flows that enter vegetation, which is also often decorrelated between successive SAR images. Along with measurements of planform morphology, we are able to show that the length of time a flow stays decorrelated after initial emplacement is linearly related to the flow thickness. Finally, we use interferograms obtained after flow surfaces become correlated to show that persistent decorrelation is caused by post-emplacement flow subsidence.

  17. A Qualitative Exploration of Participants' Experiences of Taking Part in a Walking Programme: Perceived Benefits, Barriers, Choices and Use of Intervention Resources

    Science.gov (United States)

    Mitchell, Fiona; Stalker, Kirsten; Matthews, Lynsay; Mutrie, Nanette; Melling, Chris; McConnachie, Alex; Murray, Heather; Melville, Craig A.

    2018-01-01

    Background: Adults with intellectual disabilities (ID) experience significant inequalities and tend to be more sedentary and less physically active than the wider population. Walking programmes are an effective way to increase physical activity (PA) but have not been used in studies involving adults with intellectual disabilities. Method: Nineteen…

  18. Order or chaos? Origin and mode of emplacement of breccias in floors of large impact structures

    Science.gov (United States)

    Dressler, B. O.; Reimold, W. U.

    2004-09-01

    fabric of the crater basement. The "Offset" dikes of the Sudbury Structure are associated with the Sudbury Igneous Complex that represents, in total or in part, a differentiated impact melt sheet. The dikes, in many aspects, are similar to Vredefort Granophyres, but their interpretation as undifferentiated bulk melt is problematic on geochemical and structural grounds. Chemically, these dikes are not homogeneous and, in places, they contain massive sulfide deposits that are unlikely components of an undifferentiated impact melt. Differentiation and precipitation of massive sulfides are slow processes compared with the presumably high energy and fast emplacement of a supposedly undifferentiated melt. Pseudotachylites of the central impact crater apparently are mainly produced in the compression phase of the impact process, whereas clastic-matrix breccias form during the uplift and crater modification phases. Impact melt breccia dikes contain pseudotachylite-bearing inclusions and cut across pseudotachylite bodies. Such impact melt breccia dikes were probably emplaced during uplift and crater modification.

  19. Design of a nuclear-waste package for emplacement in tuff

    International Nuclear Information System (INIS)

    O'Neal, W.C.; Rothman, A.J.; Gregg, D.W.; Hockman, J.N.; Revelli, M.A.; Russell, E.W.; Schornhorst, J.R.

    1983-01-01

    Design, modeling, and testing activities are under way at LLNL in the development of high level nuclear waste package designs. We discuss the geological characteristics affecting design, the 10CFR60 design requirements, conceptual designs, metals for containment barriers, economic analysis, thermal modeling, and performance modeling

  20. Emplacement and erosive effects of the south Kasei Valles lava on Mars

    Science.gov (United States)

    Dundas, Colin M.; Keszthelyi, Laszlo P.

    2014-01-01

    Although it has generally been accepted that the Martian outflow channels were carved by floods of water, observations of large channels on Venus and Mercury demonstrate that lava flows can cause substantial erosion. Recent observations of large lava flows within outflow channels on Mars have revived discussion of the hypothesis that the Martian channels are also produced by lava. An excellent example is found in south Kasei Valles (SKV), where the most recent major event was emplacement of a large lava flow. Calculations using high-resolution Digital Terrain Models (DTMs) demonstrate that this flow was locally turbulent, similar to a previously described flood lava flow in Athabasca Valles. The modeled peak local flux of approximately 106 m3 s−1 was approximately an order of magnitude lower than that in Athabasca, which may be due to distance from the vent. Fluxes close to 107 m3 s−1 are estimated in some reaches but these values are probably records of local surges caused by a dam-breach event within the flow. The SKV lava was locally erosive and likely caused significant (kilometer-scale) headwall retreat at several cataracts with tens to hundreds of meters of relief. However, in other places the net effect of the flow was unambiguously aggradational, and these are more representative of most of the flow. The larger outflow channels have lengths of thousands of kilometers and incision of a kilometer or more. Therefore, lava flows comparable to the SKV flow did not carve the major Martian outflow channels, although the SKV flow was among the largest and highest-flux lava flows known in the Solar System.

  1. Vertical movement in mare basins: relation to mare emplacement, basin tectonics, and lunar thermal history

    International Nuclear Information System (INIS)

    Solomon, S.C.

    1979-01-01

    The spatial and temporal relationships of linear rilles and mare ridges in the Serenitatis basin region of the moon are explained by a combination of lithospheric flexure in response to basin loading by basalt fill and a time-dependent global stress due to the thermal evolution of the lunar interior. The pertinent tectonic observations are the radial distance of basin concentric rilles or graben from the mare center; the location and orientation of mare ridges, interpreted as compressive features; and the restriction of graben formation to times older than 3.6 +- 0.2 b.y. ago, while ridge formation continued after emplacement of the youngest mare basalt unit (approx.3 b.y. ago). The locations of the graben are consistent with the geometry of the mare basalt load expected from the dimensions of multiring basins for values of the thickness of the elastic lithosphere beneath Serenitatis in the range 25--50 km at 3.6--3.8 b.y. ago. The locations and orientations of mare ridges are consistent with the load inferred from surface mapping and subsurface radar reflections for values of the elastic lithosphere thickness near 100 km at 3.0--3.4 b.y. ago. The thickening of the lithosphere beneath a major basin during the evolution of mare volcanism is thus clearly evident in the tectonics. The cessation of rille formation and the prolonged period of ridge formation are attributed to a change in the global horizontal thermal stress from extension to compression as the moon shifted from net expansion to overall cooling and contraction. Severe limits as placed on the range of possible lunar thermal histories. The zone of horizontal extensional stresses peripheral to mare loads favors the edge of mare basins as the preferred sites for mare basalt magma eruption in the later stages of mare fill, although subsidence may lead to accumulation of such young lavas in basin centers

  2. Eruption and emplacement timescales of ignimbrite super-eruptions from thermo-kinetics of glass shards

    Directory of Open Access Journals (Sweden)

    Yan eLavallée

    2015-02-01

    Full Text Available Super-eruptions generating hundreds of cubic kilometres of pyroclastic density currents are commonly recorded by thick, welded and lava-like ignimbrites. Despite the huge environmental impact inferred for this type of eruption, little is yet known about the timescales of deposition and post-depositional flow. Without these timescales, the critical question of the duration of any environmental impact, and the ensuing gravity of its effects for the Earth system, eludes us. The eruption and welding of ignimbrites requires three transects of the glass transition. Magma needs to: 1 fragment during ascent, 2 liquefy and relax during deposition, agglutination and welding (sintering, and 3 quench by cooling into the glassy state. Here we show that welding is a rapid, syn-depositional process and that the welded ignimbrite sheet may flow for up to a few hours before passing through the glass transition a final time. Geospeedometry reveals that the basal vitrophyre of the Grey’s Landing ignimbrite underwent the glass transition at a rate of ~0.1 °C.min^-1 at 870 °C; that is, 30-180 °C below pre-eruptive geothermometric estimates. Application of a 1-D cooling model constrains the timescale of deposition, agglutination, and welding of the basal vitrophyre to less than 1 hour, and possibly even tens of minutes. Thermo-mechanical iteration of the sintering process indicates an optimal temperature solution for the emplacement of the vitrophyres at 966 °C. The vitrophyres reveal a Newtonian rheology up to 46 MPa, which suggests that the ash particles annealed entirely during welding and that viscous energy dissipation is unlikely from loading conditions alone, unless shear stresses imposed by the overlying ash flow were excessively high and sustained over long distances. The findings underline the value of the term 'lava-like' flow to describe the end rheology of Snake River-type ignimbrites, fully consistent with the typical lithofacies observed.

  3. Generation and emplacement of fine-grained ejecta in planetary impacts

    Science.gov (United States)

    Ghent, R.R.; Gupta, V.; Campbell, B.A.; Ferguson, S.A.; Brown, J.C.W.; Fergason, R.L.; Carter, L.M.

    2010-01-01

    We report here on a survey of distal fine-grained ejecta deposits on the Moon, Mars, and Venus. On all three planets, fine-grained ejecta form circular haloes that extend beyond the continuous ejecta and other types of distal deposits such as run-out lobes or ramparts. Using Earth-based radar images, we find that lunar fine-grained ejecta haloes represent meters-thick deposits with abrupt margins, and are depleted in rocks 1cm in diameter. Martian haloes show low nighttime thermal IR temperatures and thermal inertia, indicating the presence of fine particles estimated to range from ???10??m to 10mm. Using the large sample sizes afforded by global datasets for Venus and Mars, and a complete nearside radar map for the Moon, we establish statistically robust scaling relationships between crater radius R and fine-grained ejecta run-out r for all three planets. On the Moon, ???R-0.18 for craters 5-640km in diameter. For Venus, radar-dark haloes are larger than those on the Moon, but scale as ???R-0.49, consistent with ejecta entrainment in Venus' dense atmosphere. On Mars, fine-ejecta haloes are larger than lunar haloes for a given crater size, indicating entrainment of ejecta by the atmosphere or vaporized subsurface volatiles, but scale as R-0.13, similar to the ballistic lunar scaling. Ejecta suspension in vortices generated by passage of the ejecta curtain is predicted to result in ejecta run-out that scales with crater size as R1/2, and the wind speeds so generated may be insufficient to transport particles at the larger end of the calculated range. The observed scaling and morphology of the low-temperature haloes leads us rather to favor winds generated by early-stage vapor plume expansion as the emplacement mechanism for low-temperature halo materials. ?? 2010 Elsevier Inc.

  4. Structural control on basaltic dike and sill emplacement, Paiute Ridge mafic intrusion complex, southern Nevada

    International Nuclear Information System (INIS)

    Carter Krogh, K.E.; Valentine, G.A.

    1996-08-01

    Late Miocene basaltic sills and dikes in the Paiute Ridge area of southern nevada show evidence that their emplacement was structurally controlled. Basaltic dikes in this area formed by dilating pre-existing vertical to steeply E-dipping normal faults. Magma propagation along these faults must have required less energy than the creation of a self-propagated fracture at dike tips and the magma pressure must have been greater than the compressive stress perpendicular to the fault surface. N- to NE-trending en echelon dikes formed locally and are not obviously attached to the three main dikes in the area. The en echelon segments are probably pieces of deeper dikes, which are segmented perhaps as a result of a documented rotation of the regional stresses. Alternatively, changes in orientation of principal stresses in the vicinity of each en echelon dike could have resulted from local loads associated with paleotopographic highs or nearby structures. Sills locally branched off some dikes within 300 m of the paleosurface. These subhorizontal bodies occur consistently in the hanging wall block of the dike-injected faults, and intrude Tertiary tuffs near the Paleozoic-Tertiary contact. The authors suggest that the change in stresses near the earth's surface, the material strength of the tuff and paleozoic rocks, and the Paleozoic bedding dip direction probably controlled the location of sill formation and direction of sill propagation. The two largest sills deflected the overlying tuffs to form lopoliths, indicating that the magma pressure exceeded vertical stresses at that location and that the shallow level and large size of the sills allowed interaction with the free (earth's) surface. 32 refs., 4 figs., 1 tab

  5. Dyke swarm emplacement in the Ethiopian Large Igneous Province: not only a matter of stress

    Science.gov (United States)

    Mège, Daniel; Korme, Tesfaye

    2004-05-01

    In the Tana-Belaya area, western Ethiopia, field data and satellite imagery reveal the existence of two dyke swarms, the NE-SW Serpent-God dyke swarm, and the NW-SE Dinder dyke swarm. Both swarms are thought to have the same age, 30 Ma, and are likely to have contributed to feeding the traps. After a description of the swarms, this paper examines their relationships with the basement structures. The two dyke swarms follow major lithospheric weakness zones. The Serpent-God dyke swarm follows the Pan-African Tulu Dimtu ductile shear zone, and the Dinder dyke swarm follows a large NW-SE-trending Precambrian fracture zone already reactivated during the Mesozoic and Cenozoic as the northern boundary of the Blue Nile Rift. Because the dyke swarms are adjacent but their orientation differs, the stress trajectory patterns during their emplacement were spatially variable at local scale. Therefore, rather than plate-boundary processes, the origin of stress is thought to be primarily related to the Ethiopian plume. Postulating (in the absence of more data relating to the magma chambers that fed the traps) that dyke orientation is the result of an axisymmetric stress field, the location of the stress source can be placed close to Lake Tana, which is the centre of the Ethiopian broad negative regional Bouguer anomaly. The dykes in the Tana-Belaya area provide the first clues to the orientation of the stress field that prevailed in the early history of the Ethiopian mantle plume, and to some of the factors that guided the distribution of the trap feeders.

  6. Natural attenuation of a plume from an emplaced coal tar creosote source over 14 years

    Science.gov (United States)

    Fraser, M.; Barker, J. F.; Butler, B.; Blaine, F.; Joseph, S.; Cooke, C.

    2008-09-01

    An emplaced source of coal tar creosote within the sandy Borden research aquifer has documented the long-term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals have been extensively sampled seven times using a monitoring network of ˜ 280, 14-point multilevel samplers. A model of source dissolution using Raoult's Law adequately predicted the dissolution of 9 of 11 compounds. Mass transformation has limited the extent of the plumes as groundwater has flowed more than 500 m, yet the plumes are no longer than 50 m. Phenol and xylenes have been removed and naphthalene has attenuated from its maximum extent on day 1357. Some compound plumes have reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass lost is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor, yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. The complex evolution of these plumes has been well documented but understanding the controlling biotransformation processes is still elusive. This study has shown that anticipating bioattenuation patterns should only be considered at the broadest scale. Generally, the greatest mass loss is associated with those compounds that have a high solubility and low partitioning coefficients.

  7. Using restored cross sections to evaluate magma emplacement, White Horse Mountains, Eastern Nevada, U.S.A.

    Science.gov (United States)

    Marko, Wayne T.; Yoshinobu, Aaron S.

    2011-03-01

    New field observations and cross section restoration from the Jurassic White Horse pluton-host rock system, Goshute Range, eastern Nevada, USA, indicate a sequential variation of host rock rheology attending magma emplacement. The pluton intruded weakly to nondeformed Devonian-Mississippian limestone, argillite and quartzite at shallow crustal levels (ca. 7 km). The contact aureole is well exposed along the southern, eastern and northern margin of the intrusive body and is less than 1 km wide. Rocks outside of the aureole are sub-horizontal and do not contain a penetrative fabric or are gently folded (interlimb angles > 120°) about sub-vertical axial planes. Within the contact aureole, continuous and discontinuous spaced, axial planar foliations and harmonic to disharmonic, tight to isoclinal folds wrap around the eastern margin of the pluton. Folds verge toward and away from the pluton and rim anticlines, synclines, and monoclines with wavelength in excess of 250 m are preserved along the pluton margin. The spatial proximity of these ductile structures to the pluton and the apparent increase in intensity of structure development approaching the pluton is compatible with contraction within the aureole attending pluton emplacement. However, all of the above structures are truncated by the intrusive contact at various scales. Granodioritic dikes ranging in thickness from 1 m up to ˜ 10 m emanate from the intrusion and cut host rock structure at high angles and turn to propagate towards one another, parallel to the pluton margin and host rock anisotropy. Such features are interpreted to reflect the last stages of diking and brittle deformation that modified the pluton contact after emplacement-related folding of the carbonate rocks, but before final solidification of the pluton. Eight serial geologic cross sections were constructed and evaluated to place geometric constraints on the shape and growth of the White Horse intrusion. Based on line-length restoration of

  8. A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

    International Nuclear Information System (INIS)

    Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A.; Myer, L.; Pellerin, L.; Pruess, K.

    1996-11-01

    This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ( 137 Cs, 90 Sr, and 238 Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and geophysical methods, was developed. A lance water injection test was conducted in order to obtain representative estimates of the hydraulic conductivity and its distribution for the design of the barrier emplacement. The water injection test demonstrated the lack of permeable zones for CS injection, and a decision not to proceed with the barrier emplacement was reached

  9. A design study for the isolation of the 281-3H retention basin at the Savannah River Site using the viscous liquid barrier technology

    Energy Technology Data Exchange (ETDEWEB)

    Moridis, G.J.; Persoff, P.; Apps, J.; James, A.; Oldenburg, C.; McGrath, A.; Myer, L.; Pellerin, L.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

    1996-11-01

    This report is a description of the design study for a pilot-scale field demonstration of the Viscous Liquid Barrier (VLB) technology, a new subsurface containment technology for waste isolation using a new generation of barrier liquids. The demonstration site was Retention Basin 281-3H, a shallow catchment basin at the Savannah River Site, which is contaminated mainly by radionuclides ({sup 137}Cs, {sup 90}Sr, and {sup 238}Pu). The goals of the field demonstration were (a) to demonstrate the ability to create a continuous subsurface barrier in order to isolate the contaminants, and (b) to demonstrate the continuity, performance, and integrity of the barrier. The site was characterized, and preliminary hydraulic conductivity data were obtained from core samples. Based on the site characteristics and the functional requirements, a conceptual model was developed, the barrier specifications were defined, and lance injection was selected as the emplacement method. The injection strategy for the subsurface conditions at the site was determined using numerical simulations. An appropriate variant of Colloidal Silica (CS) was selected as the barrier liquid based on its relative insensitivity to interactions with the site soils, and the formulation for optimum site performance was determined. A barrier verification strategy, including hydraulic, pneumatic, tracer, and geophysical methods, was developed. A lance water injection test was conducted in order to obtain representative estimates of the hydraulic conductivity and its distribution for the design of the barrier emplacement. The water injection test demonstrated the lack of permeable zones for CS injection, and a decision not to proceed with the barrier emplacement was reached.

  10. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk...

  11. Verification of the integrity of barriers using gas diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Ward, D.B. [SPECTRA Research Inst., Albuquerque, NM (United States); Williams, C.V. [Sandia National Labs., Albuquerque, NM (United States). Environmental Restoration Technologies Dept.

    1997-06-01

    In-situ barrier materials and designs are being developed for containment of high risk contamination as an alternative to immediate removal or remediation. The intent of these designs is to prevent the movement of contaminants in either the liquid or vapor phase by long-term containment, essentially buying time until the contaminant depletes naturally or a remediation can be implemented. The integrity of the resultant soil-binder mixture is typically assessed by a number of destructive laboratory tests (leaching, compressive strength, mechanical stability with respect to wetting and freeze-thaw cycles) which as a group are used to infer the likelihood of favorable long-term performance of the barrier. The need exists for a minimally intrusive yet quantifiable methods for assessment of a barrier`s integrity after emplacement, and monitoring of the barrier`s performance over its lifetime. Here, the authors evaluate non-destructive measurements of inert-gas diffusion (specifically, SF{sub 6}) as an indicator of waste-form integrity. The goals of this project are to show that diffusivity can be measured in core samples of soil jet-grouted with Portland cement, validate the experimental method through measurements on samples, and to calculate aqueous diffusivities from a series of diffusion measurements. This study shows that it is practical to measure SF{sub 6} diffusion rates in the laboratory on samples of grout (Portland cement and soil) typical of what might be used in a barrier. Diffusion of SF{sub 6} through grout (Portland cement and soil) is at least an order of magnitude slower than through air. The use of this tracer should be sensitive to the presence of fractures, voids, or other discontinuities in the grout/soil structure. Field-scale measurements should be practical on time-scales of a few days.

  12. Stochastic transport of particles across single barriers

    International Nuclear Information System (INIS)

    Kreuter, Christian; Siems, Ullrich; Henseler, Peter; Nielaba, Peter; Leiderer, Paul; Erbe, Artur

    2012-01-01

    Transport phenomena of interacting particles are of high interest for many applications in biology and mesoscopic systems. Here we present measurements on colloidal particles, which are confined in narrow channels on a substrate and interact with a barrier, which impedes the motion along the channel. The substrate of the particle is tilted in order for the particles to be driven towards the barrier and, if the energy gained by the tilt is large enough, surpass the barrier by thermal activation. We therefore study the influence of this barrier as well as the influence of particle interaction on the particle transport through such systems. All experiments are supported with Brownian dynamics simulations in order to complement the experiments with tests of a large range of parameter space which cannot be accessed in experiments.

  13. Interprofessional experiences of recent healthcare graduates: A social psychology perspective on the barriers to effective communication, teamwork, and patient-centred care.

    Science.gov (United States)

    Thomson, Krist; Outram, Sue; Gilligan, Conor; Levett-Jones, Tracy

    2015-01-01

    Achieving safe, quality health care is highly dependent on effective communication between all members of the healthcare team. This study explored the attitudes and experiences of recent healthcare graduates regarding interprofessional teamwork and communication within a clinical setting. A total of 68 pharmacy, nursing, and medicine graduates participated in 12 semi-structured focus group discussions in clinical workplaces across three Australian states. Discussion focussed on graduates' experiences of interprofessional education and its impact on their capacity for interprofessional teamwork and communication. The Social Identity and Realistic Conflict theories were used as a framework for qualitative data analysis. A consistent pattern of profession-focussed, rather than patient- or team-focussed goals was revealed along with reports of negative stereotyping, hierarchical communication, and competition for time with the patient. Graduates acknowledged the importance of communication, teamwork, and patient-centred care and felt a better understanding of the roles of other health professionals would assist them to work together for patients' wellbeing. Identifying workplace identities and differential goals has uncovered possible motivations underlying health professionals' behaviour. These insights may help improve interprofessional collaboration by focusing attention on common team goals, increasing feelings of worth and being valued among different professionals, and decreasing the need for competition.

  14. Skin barrier function

    DEFF Research Database (Denmark)

    2016-01-01

    barrier integrity, factors influencing the penetration of the skin, influence of wet work, and guidance for prevention and saving the barrier. Distinguished researchers have contributed to this book, providing a comprehensive and thorough overview of the skin barrier function. Researchers in the field...... on the subject. It covers new basic research on skin markers, including results on filaggrin and on methods for the assessment of the barrier function. Biological variation and aspects of skin barrier function restoration are discussed as well. Further sections are dedicated to clinical implications of skin...

  15. Safety- barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2008-01-01

    trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management.......Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault...

  16. Development of the SEAtrace{trademark} barrier verification and validation technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, S.D.; Lowry, W.; Walsh, R.; Rao, D.V. [Science and Engineering Associates, Santa Fe, NM (United States); Williams, C. [Sandia National Labs., Albuquerque, NM (United States). Underground Storage Technology Dept.

    1998-08-01

    In-situ barrier emplacement techniques and materials for the containment of high-risk contaminants in soils are currently being developed by the Department of Energy (DOE). Because of their relatively high cost, the barriers are intended to be used in cases where the risk is too great to remove the contaminants, the contaminants are too difficult to remove with current technologies, or the potential movement of the contaminants to the water table is so high that immediate action needs to be taken to reduce health risks. Assessing the integrity of the barrier once it is emplaced, and during its anticipated life, is a very difficult but necessary requirement. Science and Engineering Associates, Inc., (SEA) and Sandia National Laboratories (SNL) have developed a quantitative subsurface barrier assessment system using gaseous tracers in support of the Subsurface Contaminants Focus Area barrier technology program. Called SEAtrace{trademark}, this system integrates an autonomous, multi-point soil vapor sampling and analysis system with a global optimization modeling methodology to locate and size barrier breaches in real time. The methodology for the global optimization code was completed and a prototype code written using simplifying assumptions. Preliminary modeling work to validate the code assumptions were performed using the T2VOC numerical code. A multi-point field sampling system was built to take soil gas samples and analyze for tracer gas concentration. The tracer concentration histories were used in the global optimization code to locate and size barrier breaches. SEAtrace{trademark} was consistently able to detect and locate leaks, even under very adverse conditions. The system was able to locate the leak to within 0.75 m of the actual value, and was able to determine the size of the leak to within 0.15 m.

  17. Statistical analysis of the sustained lava dome emplacement and destruction processes at Popocatépetl volcano, Central México

    Science.gov (United States)

    Mendoza-Rosas, Ana Teresa; Gómez-Vázquez, Ángel; De la Cruz-Reyna, Servando

    2017-06-01

    Popocatépetl volcano reawakened in 1994 after nearly 70 years of quiescence. Between 1996 and 2015, a succession of at least 38 lava domes have been irregularly emplaced and destroyed, with each dome reaching particular volumes at specific emplacement rates. The complexity of this sequence is analyzed using statistical methods in an attempt to gain insight into the physics and dynamics of the lava dome emplacement and destruction process and to objectively assess the hazards related to that volcano. The time series of emplacements, dome residences, lava effusion lulls, and emplaced dome volumes and thicknesses are modeled using the simple exponential and Weibull distributions, the compound non-homogeneous generalized Pareto-Poisson process (NHPPP), and the mixture of exponentials distribution (MOED). The statistical analysis reveals that the sequence of dome emplacements is a non-stationary, self-regulating process most likely controlled by the balance between buoyancy-driven magma ascent and volatile exsolution crystallization. This balance has supported the sustained effusive activity for decades and may persist for an undetermined amount of time. However, the eruptive history of Popocatépetl includes major Plinian phases that may have resulted from a breach in that balance. Certain criteria to recognize such breaching conditions are inferred from this statistical analysis.

  18. Spatial distribution of ice blocks on Enceladus and implications for their origin and emplacement

    Science.gov (United States)

    Martens, Hilary R.; Ingersoll, Andrew P.; Ewald, Shawn P.; Helfenstein, Paul; Giese, Bernd

    2015-01-01

    We have mapped the locations of over 100,000 ice blocks across the south polar region of Saturn's moon Enceladus, thus generating the first quantitative estimates of ice-block number density distribution in relation to major geological features. Ice blocks were manually identified and mapped from twenty of the highest resolution (4-25 m per pixel) Cassini Imaging Science Subsystem (ISS) narrow-angle images using ArcGIS software. The 10-100 m-diameter positive-relief features are marginally visible at the resolution of the images, making ice-block identifications difficult but not impossible. Our preliminary results reveal that ice blocks in the southern hemisphere are systematically most concentrated within the geologically active South Polar Terrain (SPT) and exhibit peak concentrations within 20 km of the tiger-stripe fractures as well as close to the south pole. We find that ice blocks are concentrated just as heavily between tiger-stripe fractures as on the directly adjacent margins; although significant local fluctuations in ice-block number density do occur, we observe no clear pattern with respect to the tiger stripes or jet sources. We examine possible roles of several mechanisms for ice-block origin, emplacement, and evolution: impact cratering, ejection from fissures during cryovolcanic eruptions, tectonic disruption of lithospheric ice, mass wasting, seismic disturbance, and vapor condensation around icy fumeroles. We conclude that impact cratering as well as mass wasting, perhaps triggered by seismic events, cannot account for a majority of ice-block features within the inner SPT. The pervasiveness of fracturing at many size scales, the ubiquity of ice blocks in the inner SPT, as well as the occurrence of linear block arrangements that parallel through-cutting crack networks along the flanks of tiger stripes indicate that tectonic deformation is an important source of blocky-ice features in the SPT. Ejection during catastrophic cryovolcanic eruptions

  19. Electrokinetically Emplaced Amendments for Enhanced Bioremediation of Chlorinated Solvents in Clay: a Pilot Field Test

    Science.gov (United States)

    O'Carroll, D. M.; Inglis, A.; Head, N.; Chowdhury, A. I.; Garcia, A. N.; Reynolds, D. A.; Hogberg, D.; Edwards, E.; Lomheim, L.; Austrins, L. M.; Hayman, J.; Auger, M.; Sidebottom, A.; Eimers, J.; Gerhard, J.

    2017-12-01

    Bioremediation is an increasingly popular treatment technology for contaminated sites due to the proven success of biostimulation and bioaugmentation. However, bioremediation, along with other in-situ remediation technologies, faces limitations due to challenges with amendment delivery in low permeability media. Studies have suggested that electrokinetics (EK) can enhance the delivery of amendments in low permeability soils, such as clay. A pilot field trial was conducted to evaluate the potential for electrokinetics to support anaerobic dechlorination in clay by improving the transport of lactate and microorganisms. The study was performed on a former chlorinated solvent production facility in Ontario, Canada. Five transect cells were set up within the contaminated clay test area. Different amendments were injected in three of these cells to test various remediation strategies under the influence of EK. The other two cells were used as controls, one with EK applied and the other with no EK. This study focuses on the cell that applied electrokinetics for lactate emplacement followed by bioremediation (EK-Bio). This cell had an initial single injection of KB-1 bioaugmentation culture (SiREM, Canada) followed by injection of sodium lactate as a biostimulant while direct current was applied for 45 days between two electrodes 3 m apart. EK can enhance lactate migration by electromigration, while microorganisms have the potential to be influenced by electroosmosis of the bulk fluid or by electrophoresis of the charged bacteria themselves. All monitoring well locations in the EK-Bio cell exhibited evidence of successful lactate delivery corresponding to an increase in dissolved organic carbon. Reduction in chlorinated volatile organic compound (cVOC) concentrations, in particular 1,2-dichloroethane (1,2-DCA), were evident in monitoring locations coinciding with significant lactate breakthrough. Further investigation into the influence of EK-Bio on the abundance and

  20. Scientific networking to address the causes, timing, emplacement mechanisms, and consequences of the Messinian Salinity Crisis

    Science.gov (United States)

    Camerlenghi, Angelo; Lofi, Johanna; Aloisi, Vanni; Flecker, Rachel

    2017-04-01

    The origin of the Mediterranean salt giant is linked to an extraordinary event in the geological history of the Mediterranean region, commonly referred to as the Messinian Salinity Crisis (MSC). After 45 years of intense yet disunited research efforts, the international scientific community at large faces a unique opportunity to access the deep and marginal basins Messinian depositional successions in the Mediterranean through scientific drilling, namely through the Integrated Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). Scientific activity to promote scientific drilling offshore and onshore is in progress under the broad umbrella of the Uncovering a Salt Giant' IODP Multi-Platform Drilling proposal, that has generated the Deep-Sea Records of the Messinian Salinity Crisis (DREAM) site-specific pre-proposal for riserless drilling on Messinian marginal basins and the related ICDP-IODP amphibious initiative Investigating Miocene Mediterranean- Atlantic gateway exchange (IMMAGE). Scientific networking has begun to establish a broad cross-disciplinary research community embracing geology, geophysics, geochemistry, microbiology, and paleoclimatology. Formal networking activities represent an opportunity for the scientific community to share objectives, data, expertise and tools with industry since there is considerable interest in oil and gas exploration, and consequent hazards, targeting the Mediterranean's deep salt deposits. With the acronym MEDSALT, we have established two networks working in close cooperation: (1) COST Action CA15103 Uncovering the Mediterranean salt giant (MEDSALT) (https://medsalt.eu/) is a 4-year long network established in May 2016 comprising scientific institutions from 28 states. This COST Action will provide an opportunity to develop further our knowledge of salt rock formation addressing four overarching scientific questions: a) What are the causes, timing and emplacement mechanisms of the

  1. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian network...... analysis with operational safety management.......Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk...

  2. Lunar floor-fractured craters: Modes of dike and sill emplacement and implications of gas production and intrusion cooling on surface morphology and structure

    Science.gov (United States)

    Wilson, Lionel; Head, James W.

    2018-05-01

    Lunar floor-fractured craters (FFCs) represent the surface manifestation of a class of shallow crustal intrusions in which magma-filled cracks (dikes) rising to the surface from great depth encounter contrasts in host rock lithology (breccia lens, rigid solidified melt sheet) and intrude laterally to form a sill, laccolith or bysmalith, thereby uplifting and deforming the crater floor. Recent developments in the knowledge of lunar crustal thickness and density structure have enabled important revisions to models of the generation, ascent and eruption of magma, and new knowledge about the presence and behavior of magmatic volatiles has provided additional perspectives on shallow intrusion processes in FFCs. We use these new data to assess the processes that occur during dike and sill emplacement with particular emphasis on tracking the fate and migration of volatiles and their relation to candidate venting processes. FFCs result when dikes are capable of intruding close to the surface, but fail to erupt because of the substructure of their host impact craters, and instead intrude laterally after encountering a boundary where an increase in ductility (base of breccia lens) or rigidity (base of solidified melt sheet) occurs. Magma in dikes approaching the lunar surface experiences increasingly lower overburden pressures: this enhances CO gas formation and brings the magma into the realm of the low pressure release of H2O and sulfur compounds, both factors adding volatiles to those already collected in the rising low-pressure part of the dike tip. High magma rise velocity is driven by the positive buoyancy of the magma in the part of the dike remaining in the mantle. The dike tip overshoots the interface and the consequent excess pressure at the interface drives the horizontal flow of magma to form the intrusion and raise the crater floor. If sill intrusion were controlled by the physical properties at the base of the melt sheet, dikes would be required to approach to

  3. Therapeutic experiences of community gardens: putting flow in its place.

    Science.gov (United States)

    Pitt, Hannah

    2014-05-01

    This paper develops the concept of therapeutic place experiences by considering the role of activity. Research of community gardening finds that particular tasks are therapeutic and exhibit the characteristics of flow, but those who lack influence over their community gardening are less likely to benefit from flow as their sense of control is reduced. The notion of emplaced flow is proposed to locate individual experiences amongst socio-spatial factors which limit self-determinacy and therefore affect wellbeing. Emplacing flow prompts critical reflection on who is excluded from therapeutic place experiences, and whether sites offering momentary escape have an enduring impact on wellbeing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 2: vault model

    International Nuclear Information System (INIS)

    Johnson, L.H.; LeNeveu, D.M.; King, F.; Shoesmith, D.W.; Kolar, M.; Oscarson, D.W.; Sunder, S.; Onofrei, C.; Crosthwaite, J.L.

    1996-06-01

    A study has been undertaken to evaluate the design and long-term performance of a nuclear fuel waste disposal vault based on a concept of in-room emplacement of copper containers at a depth of 500 m in plutonic rock in the Canadian Shield. The containers, each with 72 used CANDU fuel bundles, would be surrounded by clay-based buffer and backfill materials in an array of parallel rooms, with the excavation boundary assumed to have an excavation-disturbed zone (EDZ) with a higher permeability than the surrounding rock. In the anoxic conditions of deep rock of the Canadian Shield, the copper containers are expected to survive for >10 6 a. Thus container manufacturing defects, which are assumed to affect approximately 1 in 5000 containers, would be the only potential source of radionuclide release in the vault. The vault model is a computer code that simulates the release of radionuclides that would occur upon contact of the used fuel with groundwater, the diffusive transport of these radionuclides through the defect in the container shell and the surrounding buffer, and their dispersive and convective transport through the backfill and EDZ into the surrounding rock. The vault model uses a computationally efficient boundary integral model (BIM) that simulates radionuclide mass transport in the engineered barrier system as a point source (representing the defective container) that releases radionuclides into concentric cylinders, that represent the buffer, backfill and EDZ. A 3-dimensional finite-element model is used to verify the accuracy of the BIM. The results obtained in the present study indicates the effectiveness of a design using in-room emplacement of long-lived containers in providing a safe disposal system even under permeable geosphere conditions. (author). refs., tabs., figs

  5. Barriers to physical activity among working mothers.

    Science.gov (United States)

    Dombrowski, Jill J

    2011-04-01

    Working mothers experience several barriers to physical activity. If these barriers can be identified by occupational health nurses and they can partner with working mothers to reduce these perceived barriers, the health of these workers can be improved and chronic disease risk prevented. The purpose of this study was to measure the effect of self-regulatory efficacy on physical activity among working mothers and to describe specific barriers to physical activity. The Barriers Specific Self-Efficacy Scale (BARSE) and the Kaiser Physical Activity Survey (KPAS) were used to measure the variables. Self-regulatory efficacy was found to be a strong predictor of physical activity in a diverse sample of working mothers who did not meet current recommendations for physical activity. Occupational health nurses can use these findings to design programs for groups and for counseling individuals. Copyright 2011, SLACK Incorporated.

  6. Use of electrical barriers to deter movement of round goby

    Science.gov (United States)

    Savino, Jacqueline F.; Jude, David J.; Kostich, Melissa J.; Coutant, Charles C.

    2001-01-01

    An electrical barrier was chosen as a possible means to deter movement of round goby Neogobius melanostomus. Feasibility studies in a 2.1-m donut-shaped tank determined the electrical parameters necessary to inhibit round goby from crossing the 1-m stretch of the benthic, electrical barrier. Increasing electrical pulse duration and voltage increased effectiveness of the barrier in deterring round goby movement through the barrier. Differences in activity of round goby during daytime and nocturnal tests did not change the effectiveness of the barrier. In field verification studies, an electrical barrier was placed between two blocking nets in the Shiawassee River, Michigan. The barrier consisted of a 6-m wide canvas on which were laid four cables carrying the electrical current. Seven experiments were conducted, wherein 25 latex paint-marked round goby were introduced upstream of the electrical barrier and recovered 24 h later upstream, on, and downstream of the barrier. During control studies, round goby moved across the barrier within 20 min from release upstream. With the barrier on and using the prescribed electrical settings shown to inhibit passage in the laboratory, the only marked round goby found below the barrier were dead. At reduced pulse durations, a few round goby (mean one/test) were found alive, but debilitated, below the barrier. The electrical barrier could be incorporated as part of a program in reducing movement of adult round goby through artificial connections between watersheds.

  7. Constraining Controls on the Emplacement of Long Lava Flows on Earth and Mars Through Modeling in ArcGIS

    Science.gov (United States)

    Golder, K.; Burr, D. M.; Tran, L.

    2017-12-01

    Regional volcanic processes shaped many planetary surfaces in the Solar System, often through the emplacement of long, voluminous lava flows. Terrestrial examples of this type of lava flow have been used as analogues for extensive martian flows, including those within the circum-Cerberus outflow channels. This analogy is based on similarities in morphology, extent, and inferred eruptive style between terrestrial and martian flows, which raises the question of how these lava flows appear comparable in size and morphology on different planets. The parameters that influence the areal extent of silicate lavas during emplacement may be categorized as either inherent or external to the lava. The inherent parameters include the lava yield strength, density, composition, water content, crystallinity, exsolved gas content, pressure, and temperature. Each inherent parameter affects the overall viscosity of the lava, and for this work can be considered a subset of the viscosity parameter. External parameters include the effusion rate, total erupted volume, regional slope, and gravity. To investigate which parameter(s) may control(s) the development of long lava flows on Mars, we are applying a computational numerical-modelling to reproduce the observed lava flow morphologies. Using a matrix of boundary conditions in the model enables us to investigate the possible range of emplacement conditions that can yield the observed morphologies. We have constructed the basic model framework in Model Builder within ArcMap, including all governing equations and parameters that we seek to test, and initial implementation and calibration has been performed. The base model is currently capable of generating a lava flow that propagates along a pathway governed by the local topography. At AGU, the results of model calibration using the Eldgá and Laki lava flows in Iceland will be presented, along with the application of the model to lava flows within the Cerberus plains on Mars. We then

  8. Emplaced writing figuring as a manifestation of an ecocentric mindset in the narrative art of Petra Müller

    Directory of Open Access Journals (Sweden)

    Susan Meyer

    2014-06-01

    Full Text Available The human-earth connection is a sustained theme in Petra Müller’s oeuvre. The article focuses on this connection as reflected in her narrative art, specifically in accounts that have an autobiographical proclivity. The aim of this article is to outline the nature-centred disposition of Müller’s narrative art in a more definite sense. This is achieved by paying attention to the manner in which the author (the ‘I’ in accounts where the narrator can be identified as the author herself becomes part of the natural environment – whether on a sensory, an emotive, or an intellectual level – where she finds herself and the way she responds to it. At the core of the investigation are the ways in which this reactive engagement is manifested in Müller’s prose work by the implied author and the technique ofemplaced writing. Emplaced writing, a concept created by Linda Russo, was integrated by Susan Smith with Lawrence Buell’s concept of emplacement. This term refers to the technique allowing an active awareness of self and the place physically occupied by the author, as well as how that body fits into this place, to find expression. A broader perspective and greater appreciation of Müller’s work are drawn from the insight into how her close coexistence with the earth is reflected in her narrative art by means of the technique of emplaced writing which is explored in this article as it gives voice to a strong ecocentric disposition.

  9. Design management and stress analysis of a circular rock tunnel and emplacement holes for storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Kandalaft-Ladkany, N.; Wyman, R.V.

    1992-01-01

    This paper discusses a critical path method (CPM) diagram and logic net which are used for the design cycle of the rock tunnel system for a high level nuclear waste repository. In the analysis the design tunnel is subjected to pre-existing temperature and overburden loads at time of construction. high thermal stresses develop later due to the long term influx of heat from the canisters stored in vertical emplacement holes. Results indicate that thermal stresses reach a critical level for the rock in the vicinity of the canisters which could lead to local collapse of the rock and damage to the canisters

  10. Pre-waste-emplacement ground-water travel time sensitivity and uncertainty analyses for Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Kaplan, P.G.

    1993-01-01

    Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain

  11. Multilayer moisture barrier

    Science.gov (United States)

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy

    2015-04-21

    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  12. Message maps for safety barrier awareness

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten; Duijm, Nijs Jan; Troen, Hanne

    2011-01-01

    of requirements for people, work conditions, management, learning, knowledge, experience, motivation etc. The Dutch WORM and RAM projects led to the identification of 64 types of risks and the safety barriers and performance factors linked to these risks. The Danish DanWORM project has transferred this knowledge......All people are exposed to risks in everyday life, but they seldom experience accidents. Therefore, people often believe that these accidents will never happen, and they do not see the risks. By increasing the ability to notice risks, to see safety barriers, and to assess the safety barriers......’ performance parameters continuously, it is possible to create better risk awareness on the part of employers, managers and employees. Better risk awareness by these stakeholders will make it possible to: • acknowledge and continuously control risks; • discover and manage new risks; • keep safety barriers...

  13. Message maps for Safety Barrier Awareness

    DEFF Research Database (Denmark)

    . This Situational Awareness puts a number of requirements on people, work conditions, management, learning, knowledge, experience, motivation, etc. The Dutch WORM and RAM projects led to the identification of 64 types of risks and the safety barriers and performance factors that are linked to these risks......All people are exposed to risks in every-day life, but they seldom experience accidents. Therefore people often believe that these accidents will never happen, and they will see the risks no more. By increasing the ability to notice risks, to see safety barriers, and to assess the safety barriers......’ performance parameters continuously, it is possible to create better risk awareness of employers, managers and employees. Better risk awareness of these stakeholders will make it possible that: • Risks are acknowledged and controlled continuously; • New risks are discovered and managed; • Safety barriers...

  14. Dating Kaali Crater (Estonia) based on charcoal emplaced within proximal ejecta blanket

    Science.gov (United States)

    Losiak, Anna; Wild, Eva Maria; Huber, Matthew S.; Wisniowski, Tomasz; Paavel, Kristiina; Jõeleht, Argo; Välja, Rudolf; Plado, Jüri; Kriiska, Aivar; Wilk, Jakob; Zanetti, Michael; Geppert, Wolf D.; Kulkov, Alexander; Steier, Peter; Pirkovic, Irena

    2015-04-01

    The Kaali impact field consists of nine identified craters located on the Saaremaa Island in Estonia. The largest crater is 110 m in diameter (centered around 58°22'21.94"N, 22°40'09.91" E). It was formed by impact of an IAB iron meteoroid into Silurian dolomite target rocks covered by up to a few meters of glacial till (Veski et al. 2007). The age of the Kaali impact structure is still a matter of debate, and the estimates provided by different authors vary considerably between ~6400 BC (Raukas et al. 1995, Moora et al. 2012) and ~400 BC (Rasmussen et al. 2000, Veski et al. 2001). These ages were derived by 14C dating of marker horizons, characterized by a slightly elevated iridium content within the nearby Piila bog yielding a calibrated age of 800-400 BC (Rasmussen et al. 2000, Veski et al. 2001) and occurrences of glassy siliceous material in the Piila bog (~6400 BC: Raukas et al. 1995) or iron microspherules in an organic-rich layer of the Reo gravel pit (6400 BC: Moora et al. 2012). However, the source of the foreign material within those layers was never unequivocally connected with the Kaali crater. 14C dating of material from post-impact organic sediments within Kaali impact craters yielded ages between 1800-1500 BC (Saarse et al. 1991, Veski et al. 2004) and 1450-400 BC (Aaloe et al. 1963). These dates underestimate the age of impact as organic sediments within the crater started to form at unknown period after the impact. On the other hand, Veski et al. (2004) suggested a reservoir effect that might have caused artificially "aging" of the organic matter because the crater was emplaced within Silurian dolomite which is rich in old carbon. The aim of this study is to determine the age of the Kaali crater by 14C dating of organic material covered by the continuous layer of proximal ejecta. This research was conducted in conjunction with a new structural investigation of Kaali Main (Zanetti et al. 2015). Ten samples collected from different locations

  15. Thermal barriers for compartments

    Science.gov (United States)

    Kreutzer, Cory J.; Lustbader, Jason A.

    2017-10-17

    An aspect of the present disclosure is a thermal barrier that includes a core layer having a first surface, a second surface, and a first edge, and a first outer layer that includes a third surface and a second edge, where the third surface substantially contacts the first surface, the core layer is configured to minimize conductive heat transfer through the barrier, and the first outer layer is configured to maximize reflection of light away from the barrier.

  16. Tunnel barrier schottky

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Rongming; Cao, Yu; Li, Zijian; Williams, Adam J.

    2018-02-20

    A diode includes: a semiconductor substrate; a cathode metal layer contacting a bottom of the substrate; a semiconductor drift layer on the substrate; a graded aluminum gallium nitride (AlGaN) semiconductor barrier layer on the drift layer and having a larger bandgap than the drift layer, the barrier layer having a top surface and a bottom surface between the drift layer and the top surface, the barrier layer having an increasing aluminum composition from the bottom surface to the top surface; and an anode metal layer directly contacting the top surface of the barrier layer.

  17. Intrinsic barriers for H-atom transfer reactions involving hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Camaioni, D.M.; Autrey, S.T.; Franz, J.A.

    1994-08-01

    Intrinsic barriers (formally the barrier in the absence of driving force) for H-atom transfer reactions are key parameters in Evans-Polyanyi and Marcus equations for estimating exothermic reaction barriers and are fundamentally significant for the insight they provide about bond reorganization energies for formation of transition state structures. Although knowable from experiment, relatively few of these barriers have been measured due to experimental difficulties in measuring rates for identity reactions. Thus, the authors have used semiempirical Molecular Orbital theoretical methods (MNDO/PM3) to calculate barriers for a series of H-atom transfer identity reactions involving alkyl, alkenyl, arylalkyl and hydroaryl radicals and donors. Briefly stated, they find that barriers decrease with the degree of alkyl substitution at the radical site whereas barriers increase with the degree of conjugation with the radical site. Details of the methodology and analyses of how these barrier heights correlate with reactant and transition state properties will be presented and discussed.

  18. 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

  19. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses; Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs.

  20. Low Amplitude of Geomagnetic Secular Variations Recorded in Traps of the Southern Siberian Platform: Very Fast Emplacement or Regional Remagnetization?

    Science.gov (United States)

    Veselovskiy, R. V.; Latyshev, A. V.; Pavlov, V. E.

    2011-12-01

    We have studied the lowest part of the Permo-Triassic Siberian trap sequence which is located in the middle course of the Angara river (Southern Siberia). This sequenced is composed by 200m thick volcanoclastic rocks (tuffs with bombs of different composition) and includes numerous mafic subvolcanic bodies (dykes and sills). Altogether more than 20 sites representing tuffs, bombs, dykes and sills stretched along the valley of the Angara river over the distance more than 30 km have been sampled and studied. Obtained site mean paleomagnetic directions are tightly grouped, showing very lower scatter. Taking into account that amplitude of geomagnetic secular variation at the P-T boundary was about of same order as in Late Cenozoic (Pavlov et al., 2011) this lower scatter can be either a sequence of very fast traps emplacement which could have disastrous environmental impact or a result of subsequent regional remagnetization. The only geological event in the region which seems to be capable to cause this remagnetization is emplacement of Early Triassic sills in nearby areas. In such the case we should expect that mean paleomagnetic directions from these sills will be very close to these ones obtained from site presented in this report. We present results of paleomagnetic studies of these sills and make a choice in favor of one of discussed options. This work was supported by grants NSF EAR 0807585 ("The Siberian Traps and end-Permian extinction") and RFBR 09-05-01180, 10-05-00557.

  1. Contrasting magmatic structures between small plutons and batholiths emplaced at shallow crustal level (Sierras de Córdoba, Argentina)

    Science.gov (United States)

    Pinotti, Lucio P.; D'Eramo, Fernando J.; Weinberg, Roberto F.; Demartis, Manuel; Tubía, José María; Coniglio, Jorge E.; Radice, Stefania; Maffini, M. Natalia; Aragón, Eugenio

    2016-11-01

    Processes like injection, magma flow and differentiation and influence of the regional strain field are here described and contrasted to shed light on their role in the formation of small plutons and large batholiths their magmatic structures. The final geometric and compositional arrangement of magma bodies are a complex record of their construction and internal flow history. Magma injection, flow and differentiation, as well as regional stresses, all control the internal nature of magma bodies. Large magma bodies emplaced at shallow crustal levels result from the intrusion of multiple magma batches that interact in a variety of ways, depending on internal and external dynamics, and where the early magmatic, growth-related structures are commonly overprinted by subsequent history. In contrast, small plutons emplaced in the brittle-ductile transition more likely preserve growth-related structures, having a relatively simple cooling history and limited internal magma flow. Outcrop-scale magmatic structures in both cases record a rich set of complementary information that can help elucidate their evolution. Large and small granitic bodies of the Sierra Pampeanas preserve excellent exposures of magmatic structures that formed as magmas stepped through different rheological states during pluton growth and solidification. These structures reveal not only the flow pattern inside magma chambers, but also the rheological evolution of magmas in response to temperature evolution.

  2. Tectonic burial, thrust emplacement, and extensional exhumation of the Cabot nappe in the Appalachian hinterland of Cape Breton Island, Canada

    Science.gov (United States)

    Lynch, Gregory

    1996-02-01

    Silurian imbricate thrusting, Early Devonian high-grade metamorphic nappe emplacement, and Devonian-Carboniferous extensional denudation characterize deformation in the Appalachian hinterland of Cape Breton Island. Compressional deformation following Early Silurian arc volcanism features imbrication of Cambrian-Precambrian basement rocks of Gondwana derivation with Ordovician-Silurian cover sequences across thick zones of mylonite during south directed transport. High grade metamorphism and gneissic rocks of late Silurian age in the region indicate that significant tectonic burial and crustal thickening occurred as a result of the thrusting. Partial denudation of the high grade assemblages occurred during Early Devonian thrust emplacement of the Cabot nappe toward the northwest, along the Highlands Shear Zone. The nappe is characterized by an amphibolitic gneiss and high-grade schist complex defining a large folded klippe above Silurian units. Kyanite is widespread within the nappe, and a distinctive feature of the thrust sheet is the dynamothermal metamorphism of cooler greenschist-grade footwall rocks producing inverted isograds; staurolite is regionally distributed and occurs in pelitic units in the immediate footwall of the Highlands Shear Zone forming a discontinuous halo around the klippe. Greenschist-grade footwall rocks are exposed in structural windows as a result of folding and faulting. Shear sense indicators along the margins of the Cabot nappe have been rotated into their present positions due to superposed folding, providing apparent movement directions for the nappe. Complete exhumation to surface occurred during Late Devonian extension along the low-angle Margaree Shear Zone.

  3. Geochemical significance of neoproterozoic rasimalai alkali syenite emplaced along Dharmapuri shear zone in the Northern part of Tamil Nadu

    International Nuclear Information System (INIS)

    Thangavel, S.; Balasubramani, S.; Nagaraju, M.; Bhattacharya, D.; Zakaulla, Syed; Rai, A.K.

    2015-01-01

    The Rasimalai alkali syenite complex is emplaced within Peninsular Gneissic complex and spatially associated with NE-SW trending major Dharmapuri shear zone (DSZ) in the northern part of Tamil Nadu. It is surrounded by epidote hornblend egneiss, which is the fenetised product of Charnockite and occurs about 20 km NE of Alangayam in Vellore district. It is mainly comprised of medium to coarse grained grey syenite (albite and orthoclase) and medium to micro grained pink syenite (orthoclase, microcline and perthite) at places porphyritic in nature with hornblende, riebeckitc, aegirine and acmite as accessory minerals. Grey syenite is non radioactive and uranium mineralisation is associated with pink syenite (syngenetic and disseminated type) and quartz-barite veins (hydrothermal type). Hydrothermal activity is manifested in the form of pyrite, chalcopyrite, galena, barite, calcite and calcian-strontianite which occur in the form of disseminations, stringers, lumps, aggregates, veinlets and veins. Presence of high silica (63.14-75.43%) with high field strength elements (U, Th, Nb and Pb) and large ion lithophile elements (Rb, Sr, K, Ba) possibly indicates that Rasimalai alkali syenite is the product of crustal communication and partial melting of protracted emplacement of parental alkali basaltic magma

  4. Development of engineered barrier

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-03-01

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

  5. Alternative geochemical barrier materials

    International Nuclear Information System (INIS)

    1991-07-01

    Previous investigations of the effects of neutralization and reduction on uranium mill tailings pore fluids by the Technical Support Contractor indicated that arsenic, selenium, and molybdenum continue to remain in solution in all but reducing conditions. These hazardous constituents are present in groundwaters as oxyanions and, therefore, are not expected to be removed by adsorption into clays and most other soil constituents. It was decided to investigate the attenuation capacity of two commonly available crystalline iron oxides, taconite and scoria, and a zeolite, a network aluminosilicate with a cage structure. Columns of the candidate materials were exposed to solutions of individual constituents, including arsenic, molybdenum, selenium, and, uranium, and to the spiked tailings pore fluid from the Bodo Canyon disposal cell near Durango, Colorado. In addition to the single material columns, a homogeneous blend of the three materials and layers of the materials were exposed to spiked tailings pore fluids. The results of these experiments indicate that with the exception of molybdenum, the constituents of concern are attenuated by the taconite; however, they are not sufficiently attenuated to meet the groundwater protection standards applicable to the UMTRA Project. Therefore, the candidate barrier materials did not prove to be useful to the UMTRA Project for the cleanup of groundwaters

  6. Excavation Induced Hydraulic Response of Opalinus Clay - Investigations of the FE-Experiment at the Mont Terri URL in Switzerland

    Science.gov (United States)

    Vogt, T.; Müller, H. R.; Garitte, B.; Sakaki, T.; Vietor, T.

    2013-12-01

    The Full-Scale Emplacement (FE) Experiment at the Mont Terri underground research laboratory in Switzerland is a full-scale heater test in a clay-rich formation (Opalinus Clay). Based on the Swiss disposal concept it simulates the construction, emplacement, backfilling, and post-closure thermo-hydro-mechanical (THM) evolution of a spent fuel / vitrified high-level waste (SF / HLW) repository tunnel in a realistic manner. The main aim of this experiment is to investigate SF / HLW repository-induced THM coupled effects mainly in the host rock but also in the engineered barrier system (EBS), which consists of bentonite pellets and blocks. A further aim is to gather experience with full-scale tunnel construction and associated hydro-mechanical (HM) processes in the host rock. The entire experiment implementation (in a 50 m long gallery with approx. 3 m diameter) as well as the post-closure THM evolution will be monitored using a network of several hundred sensors (state-of-the-art sensors and measurement systems as well as fiber-optic sensors). The sensors are distributed in the host rock's near- and far-field, the tunnel lining, the EBS, and on the heaters. The heater emplacement and backfilling has not started yet, therefore only the host rock instrumentation is installed at the moment and is currently generating data. We will present the instrumentation concept and rationale as well as the first monitoring results of the excavation and ventilation phase. In particular, we investigated the excavation induced hydraulic response of the host rock. Therefore, the spatiotemporal evolution of porewater-pressure time series was analyzed to get a better understanding of HM coupled processes during and after the excavation phase as well as the impact of anisotropic geomechanic and hydraulic properties of the clay-rich formation on its hydraulic behavior. Excavation related investigations were completed by means of inclinometer data to characterize the non-elastic and time

  7. Modelling dune erosion, overwash and inundation of barrier islands

    NARCIS (Netherlands)

    Hoonhout, B.; Thiel de Vries, J.S.M.

    2012-01-01

    Physical model experiments are performed at Deltares to investigate the morphological response of barrier islands on extreme storm events. The experiments included dune erosion, overwash and inundation regimes. Extensive measurement techniques made detailed comparison with numerical models possible.

  8. Transforming Education: Overcoming Barriers.

    Science.gov (United States)

    David, Jane L.; Goren, Paul D.

    Barriers to progress in educational reform exist inside and outside the education system. Some arise where new practices encounter traditional expectations and boundaries, but others go much deeper than education, such as poverty, racism, local political conflicts, and human resistance to change. The following five categories of barriers are…

  9. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  10. Microgrids : Experiences, barriers and success factors

    NARCIS (Netherlands)

    Soshinskaya, Mariya; Crijns - Graus, Wina|info:eu-repo/dai/nl/308005015; Guerrero, Josep M.; Vasquez, Juan C.

    2014-01-01

    Although microgrids have been researched for over a decade and recognized for their multitude of benefits to improve power reliability, security, sustainability, and decrease power costs for the consumer, they have still not reached rapid commercial growth. The main aim of this research is to

  11. Verification of the integrity of barriers using gas diffusion

    International Nuclear Information System (INIS)

    Ward, D.B.; Williams, C.V.

    1997-06-01

    In-situ barrier materials and designs are being developed for containment of high risk contamination as an alternative to immediate removal or remediation. The intent of these designs is to prevent the movement of contaminants in either the liquid or vapor phase by long-term containment, essentially buying time until the contaminant depletes naturally or a remediation can be implemented. The integrity of the resultant soil-binder mixture is typically assessed by a number of destructive laboratory tests (leaching, compressive strength, mechanical stability with respect to wetting and freeze-thaw cycles) which as a group are used to infer the likelihood of favorable long-term performance of the barrier. The need exists for a minimally intrusive yet quantifiable methods for assessment of a barrier's integrity after emplacement, and monitoring of the barrier's performance over its lifetime. Here, the authors evaluate non-destructive measurements of inert-gas diffusion (specifically, SF 6 ) as an indicator of waste-form integrity. The goals of this project are to show that diffusivity can be measured in core samples of soil jet-grouted with Portland cement, validate the experimental method through measurements on samples, and to calculate aqueous diffusivities from a series of diffusion measurements. This study shows that it is practical to measure SF 6 diffusion rates in the laboratory on samples of grout (Portland cement and soil) typical of what might be used in a barrier. Diffusion of SF 6 through grout (Portland cement and soil) is at least an order of magnitude slower than through air. The use of this tracer should be sensitive to the presence of fractures, voids, or other discontinuities in the grout/soil structure. Field-scale measurements should be practical on time-scales of a few days

  12. Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand

    International Nuclear Information System (INIS)

    Kim, Hye-Jin; Leitch, Megan; Naknakorn, Bhanuphong; Tilton, Robert D.; Lowry, Gregory V.

    2017-01-01

    Highlights: • Reactivity of nZVI increased linearly with nZVI concentration above 10 g/L, but was non-linear below 10 g/L. • nZVI reactivity with PCE is more sensitive to solution redox potential than solution pH. • Mass transfer limits the reactivity of emplaced nZVI under typical groundwater flow velocity. • Lowering pH increases H 2 evolution from nZVI more than reactivity with PCE. • Design of nZVI remediation strategies should consider mass loading and flow velocity on performance and lifetime. - Abstract: The effect of nZVI mass loading and groundwater velocity on the tetrachloroethylene (PCE) dechlorination rate and the hydrogen evolution rate for poly(maleic acid-co-olefin) (MW = 12 K) coated nZVI was examined. In batch reactors, the PCE reaction rate constant (3.7 × 10 −4 L hr −1 m −2 ) and hydrogen evolution rate constant (1.4 nanomol L hr −1 m −2 ) were independent of nZVI concentration above 10 g/L, but the PCE dechlorination rate decreased and the hydrogen evolution rate increased for nZVI concentration below 10 g/L. The nonlinearity between nZVI mass loading and PCE dechlorination and H 2 evolution was explained by differences in pH and E h at each nZVI mass loading; PCE reactivity increased when solution E h decreased, and the H 2 evolution rate increased with decreasing pH. Thus, nZVI mass loading of <5 g/L yields lower reactivity with PCE and lower efficiency of Fe° utilization than for higher nZVI mass loading. The PCE dechlorination rate increased with increasing pore-water velocity, suggesting that mass transfer limits the reaction at low porewater velocity. Overall, this work suggests that design of nZVI-based reactive barriers for groundwater treatment should consider the non-linear effects of both mass loading and flow velocity on performance and expected reactive lifetime.

  13. Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hye-Jin [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Chemical Research Division, Environmental Health Research Department, National Institute of Environmental Research, Incheon 404-708 (Korea, Republic of); Leitch, Megan [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Naknakorn, Bhanuphong [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Tilton, Robert D. [Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Lowry, Gregory V., E-mail: glowry@cmu.edu [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States)

    2017-01-15

    Highlights: • Reactivity of nZVI increased linearly with nZVI concentration above 10 g/L, but was non-linear below 10 g/L. • nZVI reactivity with PCE is more sensitive to solution redox potential than solution pH. • Mass transfer limits the reactivity of emplaced nZVI under typical groundwater flow velocity. • Lowering pH increases H{sub 2} evolution from nZVI more than reactivity with PCE. • Design of nZVI remediation strategies should consider mass loading and flow velocity on performance and lifetime. - Abstract: The effect of nZVI mass loading and groundwater velocity on the tetrachloroethylene (PCE) dechlorination rate and the hydrogen evolution rate for poly(maleic acid-co-olefin) (MW = 12 K) coated nZVI was examined. In batch reactors, the PCE reaction rate constant (3.7 × 10{sup −4} L hr{sup −1} m{sup −2}) and hydrogen evolution rate constant (1.4 nanomol L hr{sup −1} m{sup −2}) were independent of nZVI concentration above 10 g/L, but the PCE dechlorination rate decreased and the hydrogen evolution rate increased for nZVI concentration below 10 g/L. The nonlinearity between nZVI mass loading and PCE dechlorination and H{sub 2} evolution was explained by differences in pH and E{sub h} at each nZVI mass loading; PCE reactivity increased when solution E{sub h} decreased, and the H{sub 2} evolution rate increased with decreasing pH. Thus, nZVI mass loading of <5 g/L yields lower reactivity with PCE and lower efficiency of Fe° utilization than for higher nZVI mass loading. The PCE dechlorination rate increased with increasing pore-water velocity, suggesting that mass transfer limits the reaction at low porewater velocity. Overall, this work suggests that design of nZVI-based reactive barriers for groundwater treatment should consider the non-linear effects of both mass loading and flow velocity on performance and expected reactive lifetime.

  14. Vehicle barrier systems

    International Nuclear Information System (INIS)

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper

  15. Emplacement controls for the basaltic-andesitic radial dikes of Summer Coon volcano and implications for flank vents at stratovolcanoes

    Science.gov (United States)

    Harp, A. G.; Valentine, G. A.

    2018-02-01

    Mafic flank eruptions are common events that pose a serious hazard to the communities and infrastructure often encroaching on the slopes of stratovolcanoes. Flank vent locations are dictated by the propagation path of their feeder dikes. The dikes are commonly thought to propagate either laterally from the central conduit or vertically from a deeper source. However, these interpretations are often based on indirect measurements, such as surface deformation and seismicity at active systems, and several studies at eroded volcanoes indicate the propagation paths may be more complex. We investigated the Oligocene age Summer Coon volcano (Colorado, USA), where erosion has exposed over 700 basaltic-andesitic radial dikes, to constrain the propagation directions, geometries, and spatial distributions of mafic dikes within a stratovolcano. The mean fabric angle of aligned plagioclase crystals was measured in oriented samples from the margins of 77 dikes. Of the 41 dikes with statistically significant flow fabrics, 85% had fabric angles that were inclined—plunging both inward and outward relative to the center of the volcano. After comparing fabric angles to those reported in other studies, we infer that, while most of the dikes with outward-plunging fabrics descended toward the flanks from a source within the edifice and near its axis, dikes with inward-plunging fabrics ascended through the edifice and toward the flanks from a deeper source. A possible control for the inclination of ascending dikes was the ratio between magma overpressure and the normal stress in the host rock. While higher ratios led to high-angle propagation, lower ratios resulted in inclined emplacement. Dikes crop out in higher frequencies within a zone surrounding the volcano axis at 2500 m radial distance from the center and may be the result of ascending dikes, emplaced at similar propagation angles, intersecting the current level of exposure at common distances from the volcano axis. The process

  16. Distribución óptima de carga en emplazamientos de generadores Optimal charging distribution in emplacements of generators

    Directory of Open Access Journals (Sweden)

    Delmar Jaime García

    2012-02-01

    Full Text Available Incorporados al Sistema Eletroenergético Nacional funcionan emplazamientos de generación distribuida que representan más del 40 por ciento de la capacidad generadora instalada. Estos grupo utilizan fuel oil o diesel como combustibles por lo que lograr su explotación eficiente constituye una necesidad económica de primer orden. Se propone un instrumento computacional para lograr la mayor eficiencia en el uso del combustible mediante la distribución económica de las cargas y se desarrolla un método de optimización basado en el criterio del costo incremental del combustible para determinar el costo total de la generación del emplazamiento. Empleando un algoritmo genético simple se minimiza la función del costo mediante la asignación de las potencias a generar por cada máquina. Se comprueba la aplicabilidad del método mediante su aplicación a un emplazamiento específico. Por su rapidez y calidad de los resultados el instrumento computacional se recomienda para su explotación en emplazamientos y el despacho.The emplacements of distributed generation that represent over the 40 percent of the generating installed capability work to the electric national system incorporated. These group Fuel Oil or diesel utilize like fuels for that achieving his efficient exploitation constitutes a need cheap to run first-rate. Distribution cheap to run of loads proposes a computational instrument to achieve the bigger efficiency in the use of intervening fuel itself and a method of optimization based in the opinion of the incremental cost of fuel to determine the total cost of the generation of the emplacement develops. Using a genetic algorithm the assignment of potencies minimizes the show of the intervening cost itself to generate for each machine. His application finds to a specific summons the applicability of the intervening method. For his rapidity and quality of results the computational instrument is recommended to exploitation in

  17. Distribución óptima de carga en emplazamientos de generadores; Optimal charging distribution in emplacements of generators

    Directory of Open Access Journals (Sweden)

    Sergio de la Fé Dotres

    2014-04-01

    Full Text Available Incorporados al Sistema Eletroenergético Nacional funcionan emplazamientos de generación distribuida que representan más del 40 por ciento de la capacidad generadora instalada. Estos grupo utilizan fuel oil o diesel como combustibles por lo que lograr su explotación eficiente constituye una necesidad económica de primer orden. Se propone un instrumento computacional para lograr la mayor eficiencia en el uso del combustible mediante la distribución económica de las cargas y se desarrolla un método de optimización basado en el criterio del costo incremental del combustible para determinar el costo total de la generación del emplazamiento. Empleando un algoritmo genético simple se minimiza la función del costo mediante la asignación de las potencias a generar por cada máquina. Se comprueba la aplicabilidad del método mediante su aplicación a un emplazamiento específico. Por su rapidez y calidad de los resultados el instrumento computacional se recomienda para su explotación en emplazamientos y el despacho.  The emplacements of distributed generation that represent over the 40 percent of the generating installed capability work to the electric national system incorporated. These group Fuel Oil or diesel utilize like fuels for that achieving his efficient exploitation constitutes a need cheap to run first-rate. Distribution cheap to run of loads proposes a computational instrument to achieve the bigger efficiency in the use of intervening fuel itself and a method of optimization based in the opinion of the incremental cost of fuel to determine the total cost of the generation of the emplacement develops. Using a genetic algorithm the assignment of potencies minimizes the show of the intervening cost itself to generate for each machine. His application finds to a specific summons the applicability of the intervening method. For his rapidity and quality of results the computational instrument is recommended to exploitation in

  18. State of the art for fabricating and emplacing concrete containers into large horizontal disposal caverns in the french geological repository - 59267

    International Nuclear Information System (INIS)

    Bosgiraud, Jean-Michel; Guariso, Maurice; Pineau, Francois

    2012-01-01

    The research and development work presented in this paper was initialized by Andra in 2007. The work necessary for manufacturing and testing a full scale demonstrator is presently implemented. The case story is twofold. The first part is related to the initial development of a high performance concrete formulation used for fabricating concrete storage containers (containing Intermediate Level and Long Lived Waste primary canisters) to be stacked and emplaced into 400-m long concrete lined horizontal disposal vaults (also called cavern), excavated in the Callovo-Oxfordian clay host formation at a 550 to 600-m depth, with an inside diameter of approximately 8-m. The fabrication of the concrete boxes is illustrated. The second part presents the outcome at the end of the detailed design phase, for a system which is now being manufactured (for further test and assembly), for the emplacement of the concrete containers inside the vault. The application was engineered for remote emplacing a pile of 2 concrete containers (the containers are preliminarily stacked in a pile of 2, inside a hot cell, thanks to a ground travelling gantry crane). The emplacement process is justified and the related emplacement synoptic is illustrated. The test campaign is scheduled in 2011-2012. The successful completion of the technical trials is mandatory to confirm the mechanical feasibility of remotely emplacing concrete containers into large horizontal disposal caverns over long distances. The later display of the machinery at work in Andra's showroom will be instrumental for the confidence building process involving the various stakeholders concerned by the public enquiry period (mid-2013) preceding the deep geological repository license application (2014-2015). (authors)

  19. Recycler barrier RF buckets

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  20. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work...

  1. Converse Barrier Certificate Theorems

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2016-01-01

    This paper shows that a barrier certificate exists for any safe dynamical system. Specifically, we prove converse barrier certificate theorems for a class of structurally stable dynamical systems. Other authors have developed a related result by assuming that the dynamical system has neither...... singular points nor closed orbits. In this paper, we redefine the standard notion of safety to comply with dynamical systems with multiple singular elements. Hereafter, we prove the converse barrier certificate theorems and highlight the differences between our results and previous work by a number...

  2. Monte-Carlo based comparison of the personal dose for emplacement scenarios of spent nuclear fuel casks in generic deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Hector Sauri; Becker, Franz; Metz, Volker [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Pang, Bo [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Shenzhen Univ. (China). College of Physics and Energy

    2017-06-15

    In the operational phase of a deep geological disposal facility for high-level nuclear waste, the radiation field in the vicinity of a waste cask is influenced by the backscattered radiation of the surrounding walls of the emplacement drift. For a comparison of disposal of spent nuclear fuel in various host rocks, it is of interest to investigate the influence of the surrounding materials on the radiation field and the personal radiation exposure. In this generic study individual dosimetry of personnel involved in emplacement of casks with spent nuclear fuel in drifts in rock salt and in a clay formation was modelled.

  3. 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

  4. 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

  5. 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

  6. The origin of elevated water levels in emplacement boreholes, Pahute Mesa, Nevada Test Site: A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, G.G.; Brikowski, T.H.

    1993-12-01

    The origin of elevated water levels in emplacement boreholes at Pahute Mesa, Nevada Test Site, is uncertain. If the water is from naturally perched aquifers, then presumed ``above water table`` weapons tests may directly impact the groundwater quality. The purpose of this study is to determine the probable source of the elevated water in boreholes by comparing modeled seepage of infiltrated drilling fluids, and the seepage from a simulated naturally perched aquifer with the observed water level history. In the model, large volumes of water are infiltrated, yet return flow of fluids back into the hole stops within three days after the end of drilling and is insufficient to produce observed standing water. Return flow is limited for two reasons: (1) the volume of the saturated rock next to the borehole is small; (2) pressure head gradient direct unsaturated flow away from the borehole. Simulation of seepage from a naturally perched aquifer readily reproduces the observed water levels.

  7. Development and demonstration of prototype transportation equipment for emplacing HL vitrified waste canisters into small diameter bored horizontal disposal cells

    International Nuclear Information System (INIS)

    Seidler, Wolf K.; Bosgiraud, Jean-Michel; Londe, Louis

    2008-01-01

    Over a period of 4 and years the National Radioactive Waste Management Agency (Andra), working with a variety of Contractors mostly specializing in nuclear orientated mechanical applications, successfully designed, fabricated and demonstrated 2 very different prototype high level waste transport systems. The first system, based on air cushion technology, was developed primarily for very heavy loads (17 to 45 tonnes). The results of this work are described in a separate presentation (Paper 21) at this Conference. The second system, developed by Andra within the framework of the ESDRED Project, generally referred to as the 'Pushing Robot System' for vitrified waste canisters, is the subject of this paper. The 'Pushing Robot System' is a part of the French national disposal concept that is described in Andra's 'Dossier 2005'. The latter is a public document that can be viewed on Andra's web site (www.andra.fr). The 'Pushing Robot System' system is designed for the deep geological disposal (in clay formations) of 'C' type vitrified waste canisters. In its entirety the system provides for the transport, emplacement and, if necessary, the retrieval of those canisters. Nothing in the design of the Andra emplacement equipment would preclude its utilization in horizontal openings in other types of geological settings. Over a period of some 8 years Andra has developed the 'Pushing Robot System' in 3 phases. Initially there was only the 'Conceptual Design' (Phase 1) which was incorporated in the Dossier 2005. This was followed by Phase 2 i.e. the design and fabrication of a simplified full scale prototype system henceforth referred to a P1, which includes a Pushing Robot, a Dummy Canister and a Test Bench. P1 details were also incorporated in the Dossier 2005. Finally, during Phase 3, a second more comprehensive full scale prototype system P2 has been designed and is being assembled and tested this month. This system includes a Transport Shuttle, a Transfer Shielding Cask, a

  8. Conceptual design of retrieval systems for emplaced transuranic waste containers in a salt bed depository. Final report

    International Nuclear Information System (INIS)

    Fogleman, S.F.

    1980-04-01

    The US Department of Energy and the Nuclear Regulatory Commission have jurisdiction over the nuclear waste management program. Design studies were previously made of proposed repository site configurations for the receiving, processing, and storage of nuclear wastes. However, these studies did not provide operational designs that were suitable for highly reliable TRU retrieval in the deep geologic salt environment for the required 60-year period. The purpose of this report is to develop a conceptual design of a baseline retrieval system for emplaced transuranic waste containers in a salt bed depository. The conceptual design is to serve as a working model for the analysis of the performance available from the current state-of-the-art equipment and systems. Suggested regulations would be based upon the results of the performance analyses

  9. Conceptual design of retrieval systems for emplaced transuranic waste containers in a salt bed depository. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fogleman, S.F.

    1980-04-01

    The US Department of Energy and the Nuclear Regulatory Commission have jurisdiction over the nuclear waste management program. Design studies were previously made of proposed repository site configurations for the receiving, processing, and storage of nuclear wastes. However, these studies did not provide operational designs that were suitable for highly reliable TRU retrieval in the deep geologic salt environment for the required 60-year period. The purpose of this report is to develop a conceptual design of a baseline retrieval system for emplaced transuranic waste containers in a salt bed depository. The conceptual design is to serve as a working model for the analysis of the performance available from the current state-of-the-art equipment and systems. Suggested regulations would be based upon the results of the performance analyses.

  10. Demonstration of close-coupled barriers for subsurface containment of buried waste

    International Nuclear Information System (INIS)

    Heiser, J.; Dwyer, B.

    1995-01-01

    The primary objective of this project is to develop and demonstrate a close-coupled barrier for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional cement grout curtain followed by a thin lining of a polymer grout. The resultant barrier is a cement polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. Close-coupled barrier technology is applicable for final, interim, or emergency containment of subsurface waste forms. Consequently, when considering the diversity of technology application, the construction emplacement and material technology maturity, general site operational requirements, and regulatory compliance incentives, the close-coupled barrier system provides an alternative for any hazardous or mixed waste remediation plan. This paper will discuss the installation of a close-coupled barrier and the subsequent integrity verification. The demonstration will take place at a cold site at the Hanford Geotechnical Test Facility, 400 Area, Hanford, Washington

  11. Analysis of heat and mass transport processes near an emplaced nuclear waste canister

    International Nuclear Information System (INIS)

    Keller, C.

    1990-01-01

    A review has been performed of the models and experimental plans for evaluation of the spent fuel canister environment in a nuclear repository, e.g., the planned Yucca Mountain facilities. Special emphasis was placed on the relevance of the models and experiments to the 100 to 10,000 year prediction. The question was addressed whether one could justify testing in materials other than Yucca Mountain rock and obtain results in a relatively short time which would be relevant to the long time in Yucca Mountain. The paper discusses steam evolution in calculations and experiments, fracture models, possible measurements of relative permeability, and long time scale effects. 5 figs. (MB)

  12. Optimistic barrier synchronization

    Science.gov (United States)

    Nicol, David M.

    1992-01-01

    Barrier synchronization is fundamental operation in parallel computation. In many contexts, at the point a processor enters a barrier it knows that it has already processed all the work required of it prior to synchronization. The alternative case, when a processor cannot enter a barrier with the assurance that it has already performed all the necessary pre-synchronization computation, is treated. The problem arises when the number of pre-sychronization messages to be received by a processor is unkown, for example, in a parallel discrete simulation or any other computation that is largely driven by an unpredictable exchange of messages. We describe an optimistic O(log sup 2 P) barrier algorithm for such problems, study its performance on a large-scale parallel system, and consider extensions to general associative reductions as well as associative parallel prefix computations.

  13. Barrier Infrared Detector (BIRD)

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in MWIR detector design, has resulted in a high operating temperature (HOT) barrier infrared detector (BIRD) that is capable of spectral...

  14. Protective barrier development: Overview

    International Nuclear Information System (INIS)

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

    1990-01-01

    Protective barrier and warning marker systems are being developed to isolate wastes disposed of near the earth's surface at the Hanford Site. The barrier is designed to function in an arid to semiarid climate, to limit infiltration and percolation of water through the waste zone to near-zero, to be maintenance free, and to last up to 10,000 yr. Natural materials (e.g., fine soil, sand, gravel, riprap, clay, asphalt) have been selected to optimize barrier performance and longevity and to create an integrated structure with redundant features. These materials isolate wastes by limiting water drainage; reducing the likelihood of plant, animal, and human intrusion; controlling emission of noxious gases; and minimizing erosion. Westinghouse Hanford Company and Pacific Northwest Laboratory efforts to assess the performance of various barrier and marker designs will be discussed

  15. Zircon U-Pb geochronology and emplacement history of intrusive rocks in the Ardestan section, central Iran

    Energy Technology Data Exchange (ETDEWEB)

    Sarjoughian, F.; Kananian, A.

    2017-11-01

    The Urumieh-Dokhtar Magmatic Arc (UDMA) is part of the Alpine–Himalayan orogenic belt and interpreted to be a subduction-related Andean-type magmatic arc. Along this belt, Eocene volcanics and some gabbroic to granitic bodies crop out. The main rock types of the studied intrusion are granite, granodiorite, and diorite. They have geochemical features typical of magnesian, calc-alkaline, metaluminous to slightly peraluminous granites and I-type intrusive rock that have a strong enrichment in Large-Ion Lithophile (LIL) elements (e.g. Rb, Ba, Sr), and a depletion in High Field Strength (HFS) elements (e.g. Nb, Ti, P), typical of subduction-related magmas. Zircon U-Pb dating was applied to determine the emplacement ages of the different intrusions in the Ardestan area. Among them the Kuh-e Dom diorite is 53.9±0.4Ma old; the Kuh-e Dom granodiorite is 51.10±0.4Ma old; the Mehrabad granodiorite is 36.8±0.5Ma old, the Nasrand granodiorite is 36.5±0.5Ma old, the Zafarghand granodiorite is 24.6±1.0Ma old, and the Feshark granodiorite is 20.5±0.8Ma old. These results delineate more accurately the magmatic evolution related to the Neotethyan subduction from the Lower Eocene to Lower Miocene, and the subsequent Zagros orogeny that resulted from the Arabia-Eurasia collision. The emplacement of these intrusive rocks inside the UDMA, which has a close relationship with the collisional orogeny, is transitional from a subduction-related setting to post-collisional setting in the Ardestan area.

  16. Granite emplacement at the termination of a major Variscan transcurrent shear zone: The late collisional Viseu batholith

    Science.gov (United States)

    Valle Aguado, B.; Azevedo, M. R.; Nolan, J.; Medina, J.; Costa, M. M.; Corfu, F.; Martínez Catalán, J. R.

    2017-05-01

    A major event of plutonic activity occurred all across the Central Iberian Zone of the Iberian Variscan Belt at the end of Late Paleozoic Variscan collisional tectonism. The present study focuses on the western sector of the Viseu late-post-tectonic batholith (central Portugal), a large composite intrusion comprising three main plutonic units: (a) small bodies of mafic to intermediate composition preferentially concentrated along the northern border, (b) a wide ring of coarse porphyritic biotite monzogranite (Cota-Viseu granite) and (c) a more evolved medium porphyritic, biotite-muscovite monzogranite occupying the central part of the intrusion (Alcafache granite). The compositional zonation pattern of the whole batholith and the complex mixing/mingling relationships between the voluminous Cota-Viseu porphyritic granite and the mafic/intermediate rocks suggest that these melts were withdrawn from a lower crustal source region undergoing partial melting, invasion by mantle-derived mafic magmas, mixing and fractional crystallization. New CA-ID-TIMS U-Pb zircon ages indicate that pluton assembly via multipulse injection of successive magma batches took place between 299.4 ± 0.4 Ma and 296.0 ± 0.6 Ma. A detailed anisotropy of magnetic susceptibility (AMS) survey suggests that pluton emplacement occurred at the extensional termination of a regional-scale, ENE-WSW trending, sinistral D3 shear zone - the Juzbado-Penalva Shear Zone (JPSZ). A dilational opening model involving the development of "en-échelon" tensional gashes at the extensional termination of the fault, followed by progressive opening and widening of north-south trending fractures, provided the space into which the successive magma batches arriving from below were emplaced. Vertical inflation was accommodated by depression of the pluton floor. The proposed model is consistent with the asymmetric wedge-shaped geometry of the intrusion (steep root zone on the northern side, discordant subvertical walls and

  17. Emplacement of Holocene silicic lava flows and domes at Newberry, South Sister, and Medicine Lake volcanoes, California and Oregon

    Science.gov (United States)

    Fink, Jonathan H.; Anderson, Steven W.

    2017-07-19

    This field guide for the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly 2017 focuses on Holocene glassy silicic lava flows and domes on three volcanoes in the Cascade Range in Oregon and California: Newberry, South Sister, and Medicine Lake volcanoes. Although obsidian-rich lava flows have been of interest to geologists, archaeologists, pumice miners, and rock hounds for more than a century, many of their emplacement characteristics had not been scientifically observed until two very recent eruptions in Chile. Even with the new observations, several eruptive processes discussed in this field trip guide can only be inferred from their final products. This makes for lively debates at outcrops, just as there have been in the literature for the past 30 years.Of the three volcanoes discussed in this field guide, one (South Sister) lies along the main axis defined by major peaks of the Cascade Range, whereas the other two lie in extensional tectonic settings east of the axis. These two tectonic environments influence volcano morphology and the magmatic and volcanic processes that form silicic lava flows and domes. The geomorphic and textural features of glass-rich extrusions provide many clues about their emplacement and the magma bodies that fed them.The scope of this field guide does not include a full geologic history or comprehensive explanation of hazards associated with a particular volcano or volcanic field. The geochemistry, petrology, tectonics, and eruption history of Newberry, South Sister, and Medicine Lake volcanic centers have been extensively studied and are discussed on other field excursions. Instead, we seek to explore the structural, textural, and geochemical evolution of well-preserved individual lava flows—the goal is to understand the geologic processes, rather than the development, of a specific volcano.

  18. The role of viscosity in the emplacement of high-temperature acidic flows of Serra Geral Formation in Torres Syncline (Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Matheus Silva Simões

    Full Text Available The acidic flows from Serra Geral Formation in Torres Syncline, Rio Grande do Sul, Brazil, are on the top of a volcanic sequence composed by a complex facies association of compound, simple and rubbly pahoehoebasic flows, acidic lava domes, and tabular acidic lava flows. The origin and emplacement conditions of the acidic volcanic rocks are discussed in this paper based on petrology, on calculated apatite saturation thermometry temperatures, and on estimated viscosity data. The liquidus temperatures for metaluminous rhyodacite to rhyolite samples are about 1,067.5 ± 25ºC in average. The viscosity (η values vary from 105 to 106 Pas for anhydrous conditions, suggesting the emplacement of high-temperature - low-viscosity lava flows and domes. The occurrence of acidic lava domes above simple pahoehoe flows as flow-banded vitrophyres was under low effusion rates, in spite of their high temperature and low viscosities, which are reflected in their small height. The emplacement of lava domes has continued until the eruption of rubbly pahoehoe flows and the geometry of these deposits rugged the relief. Presence of tabular acidic lava flows covering the landscape indicates that it was under high effusion rates conditions and such flows had well-insulated cooled surface crusts. The capacity to attain greater distances and overpass relief obstacles is explained not only by high effusion rates, but also by very low viscosities at the time of emplacement.

  19. LIP volcanism and paleo-environmental crises - impact of magma emplacement sequence on thermogenic degassing rates from the Karoo sedimentary basin

    Science.gov (United States)

    Galerne, Christophe; Hasenclever, Jörg

    2017-04-01

    Volcanism in organic-rich sedimentary basins leading to thermogenic greenhouse gas generation has been documented as a strong forcing factor of past mass extinctions. However, quantitative studies fail to provide degassing rate estimates that would allow a direct comparison with anthropogenic warming. We are investigating different sill-emplacement sequences of a Large Igneous Province (LIP) plumbing system to identify their potential variable impact in terms of thermogenic degassing rates and cumulative amount of gas released at the basin top. We use a 2D finite element model that solves for hydrothermal fluid flow and thermal evolution around several cooling intrusions. Igneous sills are represented by horizontally dominated thermal anomalies that are sequentially placed within the sedimentary basin. We test different end-member scenarios of emplacement like bottom-to-top, top-to-bottom, and arbitrary emplacement order. Degassing pulses monitored during the simulations are recorded and compared for various end-member scenarios. The LIP emplaced in the Karoo Basin (South Africa, 183 Ma) is considered as a case study. We use basin lithostratigraphic properties (e.g. Total Organic Carbon content, sill to sediment proportion and structural data) to discuss results of our end-member models. This research potentially holds the key to demonstrate whether or not anthropogenic warming is in a comparable range to a documented paleo-environmental crisis and mass extinction triggered by degassing related volcanism.

  20. 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).

  1. 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)

  2. The oceanic sediment barrier

    International Nuclear Information System (INIS)

    Francis, T.J.G.; Searle, R.C.; Wilson, T.R.S.

    1986-01-01

    Burial within the sediments of the deep ocean floor is one of the options that have been proposed for the disposal of high-level radioactive waste. An international research programme is in progress to determine whether oceanic sediments have the requisite properties for this purpose. After summarizing the salient features of this programme, the paper focuses on the Great Meteor East study area in the Northeast Atlantic, where most oceanographic effort has been concentrated. The geological geochemical and geotechnical properties of the sediments in the area are discussed. Measurements designed to determine the rate of pore water movement through the sediment column are described. Our understanding of the chemistry of both the solid and pore-water phases of the sediment are outlined, emphasizing the control that redox conditions have on the mobility of, for example, naturally occurring manganese and uranium. The burial of instrumented free-fall penetrators to depths of 30 m beneath the ocean floor is described, modelling one of the methods by which waste might be emplaced. Finally, the nature of this oceanic environment is compared with geological environments on land and attention is drawn to the gaps in our knowledge that must be filled before oceanic burial can be regarded as an acceptable disposal option. (author)

  3. Prioritising the implementation of practices to overcome operational barriers in reverse logistics

    Directory of Open Access Journals (Sweden)

    Amanda Badenhorst

    2016-09-01

    Conclusion: The framework developed in this article will enable organisations to identify the operational barriers they experience in reverse logistics and the practices they can implement on a priority basis to overcome these barriers.

  4. Effects of irregular basement structure on the geometry and emplacement of frontal thrusts and duplexes in the Quebec Appalachians: Interpretations from well and seismic reflection data

    Science.gov (United States)

    Konstantinovskaya, E.; Malo, M.; Badina, F.

    2014-12-01

    Irregular basement geometry may affect thrust propagation in foreland fold-thrust belts creating a perturbation in structural continuity of hydrocarbon fields. Here we investigate how the irregular pattern of normal faults, along with the presence of uplifts and transverse faults in the Grenvillian basement has influenced the geometry and emplacement of frontal thrusts and duplexes in the parautochthonous domain of the southern Quebec Appalachians during the middle-late Ordovician Taconian orogeny. Integration of data from surface geology, wells, and 2D and 3D seismic reflection surveys into a regional-scale structural model is used to reconstruct the 3D geometry and emplacement history of one- and two-horse duplexes in the Joly-Saint-Flavien gas storage area. The normal hinterland to foreland sequence of thrusting in this area is complicated by the differential emplacement of tectonic slices along strike of the orogenic front, starting in the SW and developing subsequently to the NE within each structural level. The shortening related to duplex emplacement decreases laterally over the distance of 20 km from - 49% in the SW (Joly area) to - 31% in the NE (Saint-Flavien area). Duplex emplacement resulted from the differential forward propagation, deflexion and vertical-axis rotation of the roof thrust (Logan's Line), which, in turn, has been induced by the presence of frontal uplift and transverse faults in the basement. The structural-lithological analysis of tectonic slices and restoration of their initial location allows us to consider the lower slice of the Joly duplex as a structural trap comparable to the fractured reservoir in lower Ordovician dolomites of the Saint-Flavien duplex.

  5. Radioactive waste isolation in salt: Peer review of the Fluor Technology, Inc., report and position paper concerning waste emplacement mode and its effect on repository conceptual design

    International Nuclear Information System (INIS)

    Hambley, D.F.; Russell, J.E.; Whitfield, R.G.

    1987-02-01

    Recommendations for revising the Fluor Technology, Inc., draft position paper entitled Evaluation of Waste Emplacement Mode and the final report entitled Waste Package/Repository Impact Study include: reevaluate the relative rankings for the various emplacement modes; delete the following want objectives: maximize ability to locate the package horizon because sufficient flexibility exists to locate rooms in the relatively clean San Andres Unit 4 Salt and maximize far-field geologic integrity during retrieval because by definition the far field will be unaffected by thermal and stress perturbations caused by remining; give greater emphasis to want objectives regarding cost and use of present technology; delete the following statements from pages 1-1 and 1-2 of the draft position paper: ''No thought or study was given to the impacts of this configuration [vertical emplacement] on repository construction or short and long-term performance of the site'' and ''Subsequent salt repository designs adopted the vertical emplacement configuration as the accepted method without further evaluation.''; delete App. E and lines 8-17 of page 1-4 of the draft position paper because they are inappropriate; adopt a formal decision-analysis procedure for the 17 identified emplacement modes; revise App. F of the impact study to more accurately reflect current technology; consider designing the underground layout to take advantage of stress-relief techniques; consider eliminating reference to fuel assemblies <10 yr ''out-of-reactor''; model the temperature distribution, assuming that the repository is constructed in an infinitely large salt body; state that the results of creep analyses must be considered tentative until they can be validated by in situ measurements; and reevaluate the peak radial stresses on the waste package so that the calculated stress conditions more closely approximate expected in situ conditions

  6. Midwives unable to overcome language barriers in prenatal care

    NARCIS (Netherlands)

    M.P. Fransen (Mirjam); H.I.J. Wildschut (Hajo); J.P. Mackenbach (Johan); E.A.P. Steegers (Eric); M.L.E. Essink-Bot (Marie-Louise)

    2012-01-01

    textabstractBackground: The present study aims to explore to what extent midwives experience barriers in providing information about prenatal screening for Down syndrome to women from diverse ethnic backgrounds, and to assess their competences to overcome these barriers. Methods: Midwives from 24

  7. Intestinal Barrier and Behavior.

    Science.gov (United States)

    Julio-Pieper, M; Bravo, J A

    2016-01-01

    The intestinal barrier function contributes to gut homeostasis by modulating absorption of water, electrolytes, and nutrients from the lumen into the circulation while restricting the passage of noxious luminal substances and microorganisms. Chronic conditions such as rheumatoid arthritis, inflammatory bowel disease, and celiac disease are associated to intestinal barrier dysfunction. Here, the hypothesis is that a leaky intestinal wall allowing for indiscriminate passage of intraluminal compounds to the vascular compartment could in turn lead to systemic inflammation. An increasing number of studies are now investigating the association between gut permeability and CNS disorders, under the premise that translocation of intestinal luminal contents could affect CNS function, either directly or indirectly. Still, it is unknown whether disruption of intestinal barrier is a causative agent or a consequence in these situations. Here, we discuss the latest evidence pointing to an association between increased gut permeability and disrupted behavioral responses. © 2016 Elsevier Inc. All rights reserved.

  8. Skin barrier in rosacea*

    Science.gov (United States)

    Addor, Flavia Alvim Sant'Anna

    2016-01-01

    Recent studies about the cutaneous barrier demonstrated consistent evidence that the stratum corneum is a metabolically active structure and also has adaptive functions, may play a regulatory role in the inflammatory response with activation of keratinocytes, angiogenesis and fibroplasia, whose intensity depends primarily on the intensity the stimulus. There are few studies investigating the abnormalities of the skin barrier in rosacea, but the existing data already show that there are changes resulting from inflammation, which can generate a vicious circle caused a prolongation of flare-ups and worsening of symptoms. This article aims to gather the most relevant literature data about the characteristics and effects of the state of the skin barrier in rosacea. PMID:26982780

  9. Health Barriers to Learning

    Directory of Open Access Journals (Sweden)

    Delaney Gracy

    2014-01-01

    Full Text Available This article summarizes the results from a 2013 online survey with 408 principals and assistant principals in New York City public elementary and middle schools. The survey assessed three primary areas: health issues in the school, health issues perceived as barriers to learning for affected students, and resources needed to address these barriers. Eighteen of the 22 health conditions listed in the survey were considered a moderate or serious issue within their schools by at least 10% of respondents. All 22 of the health issues were perceived as a barrier to learning by between 12% and 87% of the respondents. Representatives from schools that serve a higher percentage of low-income students reported significantly higher levels of concern about the extent of health issues and their impact on learning. Respondents most often said they need linkages with organizations that can provide additional services and resources at the school, especially for mental health.

  10. New insights into the timing, triggers and emplacement processes of prodigious submarine landslides in the Nordic Seas

    Science.gov (United States)

    Talling, Peter; Pope, Ed; Hunt, James; Allin, Joshua; Cartigny, Matthieu; Long, David; Mozzato, Alessandro; Stanford, Jennifer; Tappin, David; Watts, Camilla

    2015-04-01

    Submarine landslides can generate tsunamis with the potential to cause severe damage. This is illustrated by the huge (> 3,000 cubic km) Storegga landslide offshore Norway that occurred 8,200 years ago, and which produced a tsunami that ran up surrounding coastlines for up to 20m. Here we report on a 1 month research cruise on the RV Pelagia in July 2014 to the Nordic Seas, which collected 88 sediment cores totalling more than 500m, together with over 7,000 square km of swath bathymetry. The overall aim of this research expedition was to better understand the tsunami risk from large submarine landslides in the Nordic Seas. This includes a better understanding of the timing and frequency of submarine landslides, factors that potentially trigger or precondition slope failure, and the manner in which landslides are emplaced. Much of the expedition was then devoted to understanding the age and emplacement mechanism of the ~900 cubic km Traenadjupet landslide, located to the north of the Storegga Slide. This included sampling and mapping of the main Traenadjupet Slide, four lobes froming the distal Traenadjupet Slide deposit. A newly discovered debris flow deposit with large blocks was found to continue from the most westerly of these lobes, and it was mapped to its termination. If the previously established age of ~4ka for the Traenadjupet Slide is correct, then it does not appear to produced a major tsunami (unlike the Storegga Slide). Indeed, the morphology of the Traenadjupet Slide suggests much slower emplacement than the Storegga Slide, which would be consistent with such a lack of major tsunami. Turbidites in cores from the deep-water Lofoten Basin will help to understand the frequency and character of faster moving slope failures around the basin margin. Cores were collected from the Lofoten Contourite Drift located next to the Traenadjupet Slide, and these contouritic sediment may provide a paleoceanographic record that can be compared to slide timing, in order

  11. International Expert Review of SRCan: Engineered Barrier Issues. External review contribution in support of SKI's and SSI's review of SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David (Quintessa Limited, Henley-on-Thames (GB)); Bennett, David (TerraSalus Limited, Oakham (GB)); Apted, Mick (Monitor Scientific LLC, Denver, CO (US)); Saellfors, Goeran (Chalmers Univ. of Technology, Goeteborg (SE)); Saario, Timo (VTT Materials and Building (FI)); Segle, Peter (Inspecta, Stockholm (SE))

    2008-03-15

    of uncertainties in SKB's programme and safety reports, some of which relate to issues that appear to be of sufficient significance that they will need to be thoroughly addressed in the SR-Site safety report in time for the repository licence application. Other less urgent issues might be identified in SR-Can as uncertainties to be addressed through an appropriate performance confirmation programme. Performance confirmation may be defined as the programme of tests, experiments and analyses, conducted to evaluate the adequacy of the information used to demonstrate compliance with long-term safety standards for a geological repository. The most significant of the issues identified by the EBS review group include: - Demonstration of the feasibility of EBS emplacement. SKB will need to present more details on the reference EBS design, on its reference repository construction method, and on the specifications for the EBS materials. In particular, SKB still needs to demonstrate satisfactorily that the EBS can be successfully fabricated and emplaced in the appropriate configuration under repository conditions and at the rates that are projected to be required during waste disposal. SKB needs to develop and test quality assurance and quality control procedures for repository construction and operation, including EBS emplacement. SKB also needs to conduct further tests of EBS emplacement, and to characterise the as-emplaced EBS components. More generally, SKB should describe and explain in more detail how its schedule for developing plans and procedures and for conducting laboratory experiments and underground tests relates to the schedules for safety assessment and licensing. - Canister manufacture and integrity. The view of the review group is that SKB should consider a number of issues in greater detail to build further confidence in the proposed approach for canister manufacture and in the assessments of canister integrity and performance. For example, SKB could

  12. Lava Flow Emplacement Processes and Eruptive Characteristics of the Ontong Java Plateau: Inferences from High-Precision Glass Analysis

    Science.gov (United States)

    Trowbridge, S. R.; Michael, P. J.

    2015-12-01

    High-precision major and volatile element analyses were performed on natural basaltic glass from ODP Leg 192 Sites 1185 and 1187 of the Ontong Java Plateau (OJP) as a way to correlate lava flows within and between ODP drill sites. The ultimate goal is to estimate the dimensions, emplacement style, and eruption characteristics of the high-MgO Kroenke-type lavas: the youngest known flows at the two sites. The 122-Ma Ontong Java Plateau is the largest known magmatic event in Earth's history, yet little is known of the emplacement style (e.g. flow dimensions and durations) of OJP lavas due to its submarine nature and burial beneath hundreds of meters of sediment. Basalt samples were recovered from 110- and 130-m thick core sections from Sites 1185B and 1187A, respectively. Total Kroenke-type lava thickness is 125 m at 1185B and >136 m at 1187. Site 1187A is located 146 km north of Site 1185B and lies ≈50 m shallower than Site 1187. Remarkably, all of the glass compositions from both sites fall on a common liquid line of descent, suggesting that all lavas were the product of a single eruption from a common magma chamber. The range of MgO compositions reflects a 20ºC range in temperature, representing ~1.9% crystallization of olivine + spinel. Using measured phenocryst abundance, we examine whether this crystallization occurred within the magma chamber or during long transport of lavas on the seafloor. More primitive lavas are present in the upper 30 m of Site 1185B (average of ~9.54 wt. % MgO), overlying more fractionated lavas (average of ~9.06 wt. % MgO). Lavas from Site 1187A bridge the gap between the high- and low-MgO groups of 1185B. In contrast to MORB, OJP glasses have no vesicles, suggesting they remained liquid for much longer during flow. Paleoeruption depths calculated from H2O and CO2 contents of glasses show no systematic variation with depth in Core 1185B, and range from ~2130-2650 mbsl, while Site 1187 shows deeper eruption depths of ~2410-3040 mbsl

  13. Emplacement Dynamics and Timescale of a Holocene Flow from the Cima Volcanic Field (CA): Insights from Rheology and Morphology

    Science.gov (United States)

    Soldati, A.; Beem, J. R.; Gomez, F.; Huntley, J. W.; Robertson, T.; Whittington, A. G.

    2017-12-01

    We present a rheological and morphological study of a Holocene lava flow emitted by a monogenetic cinder cone in the Cima Volcanic Field, eastern California. By combining field observations and experimental results, we reconstructed the few weeks-long emplacement timeline of the Cima flow. Sample textural analyses revealed that the near-vent portion of the flow is significantly more crystalline (fxtal=0.95±0.04) than the main flow body (fxtal=0.66±0.11), which reveals a multi-stage emplacement history. Airborne photogrammetry data were used to generate a digital elevation model, which allowed us to estimate the flow volume. The rheology of Cima lavas was determined experimentally by concentric cylinder viscometry between 1550 °C and 1160 °C, including the first subliquidus rheology measurements for a continental intraplate trachybasaltic lava. The experimentally determined effective viscosity increases from 54 Pa·s to 1,361 Pa·s during cooling from the liquidus ( 1230 ˚C) to 1160 ˚C, where crystal fraction is 0.11. Flow curves fitted to measurements at different strain rates indicate a Herschel-Bulkley rheological behavior, combining shear-thinning with a yield strength negligible at the higher measured temperatures but increasing up to 357±41 Pa at 1160˚C. The lava viscosity over this range is still lower than most basaltic melts, due to the high alkali content of Cima lavas ( 6 wt% Na2O+K2O). We determined that the morphological pahoehoe to `a'ā transition of this trachybasalt occurs at a temperature of 1160±10 ˚C, similar to that observed for Hawaiian tholeiitic lavas, but at higher apparent viscosity values. Monogenetic volcanism in the Western United States is typically characterized by low effusion rates and eruption on sub-horizontal desert plains. Under these low strain-rate conditions, the pahoehoe to `a'ā transition is likely to occur abruptly upon minimal cooling, i.e. very close to the vent, but lava tubes may transport fluid lava to flow

  14. OSL surface exposure dating of wave-emplaced coastal boulders - Research concept and first results from the Rabat coast, Morocco

    Science.gov (United States)

    Brill, Dominik; May, Simon Matthias; Mhammdi, Nadia; King, Georgina; Brückner, Helmut

    2017-04-01

    Fields of wave-emplaced blocks and boulders represent impressive evidence of cyclone and tsunami flooding over Holocene time scales. Unfortunately, their use for coastal hazard assessment is in many cases impeded by the absence of appropriate dating approaches, which are needed to generate robust chronologies. The commonly applied AMS-14C, U/Th or ESR dating of coral-reef rocks and marine organisms attached to the clasts depends on a - mostly hypothetical - coincidence between the organisms' death and boulder displacement, and inferred event chronologies may be biased by the marine 14C-reservoir effect and reworked organisms. Here we discuss the potential of the recently developed optically stimulated luminescence (OSL) surface exposure dating technique to directly date the relocation process of wave-emplaced boulders. By measuring the depth-dependent resetting of luminescence signals in exposed rock surfaces and comparing it to the signal-depth profiles of known-age samples, OSL surface exposure dating may be capable to model direct depositional ages for boulder transport. Thereby, it promises to overcome the limitations of existing dating techniques, and to decipher complex transport histories of clasts that underwent multiple phases of exposure and burial. The concept and some first results of OSL surface exposure dating shall be presented for coastal boulders from the Rabat coast, Morocco, where the preconditions for successful dating are promising: (i) Several coastal boulders show clear indication of overturning during wave transport in the form of downward-facing bio-eroded surfaces; (ii) the boulders are composed of different types of sandstone that contain quartz and feldspar, the required dosimeters for OSL dating; (iii) all boulders are of Holocene age and, therefore, in the dating range of OSL surface exposure dating. The main challenges for a successful application are the intensive bio-erosion and weathering of some surfaces exposed after transport

  15. Development and testing of the pneumatic lunar drill for the emplacement of the corner cube reflector on the Moon

    Science.gov (United States)

    Zacny, K.; Currie, D.; Paulsen, G.; Szwarc, T.; Chu, P.

    2012-10-01

    Lunar Laser Ranging provides a highly accurate measurement of the distance between ground stations on Earth and reflectors on the surface of the Moon. Since retroreflectors were initially placed during the Apollo missions, the ground stations improved the ranging accuracy by a factor of 200 and now the Apollo-era arrays on the Moon pose a significant limitation to the ranging accuracy. The new Lunar Laser Ranging Retroreflector (i.e. the Lunar Laser Ranging retroreflector for the 21st century or LLRRA-21) would provide extensive new information on the lunar interior, general relativity, and cosmology. During the day/night lunar cycle, when the thermal variation of the surface is approximately 300 °C, the regolith will rise and fall by almost 500 μm. Yet, it is estimated that the thermal variation 0.5 m to 1 m below the surface is less than much 1 °C. Thus for the lunar emplacement to support 10s of microns ranging accuracy, the reflectors must be anchored to that thermally stable mass at 0.5 m or greater depth. In this paper, we present a novel method of deploying LLRRA-21 with a Corner Cube Reflector (CCR) on the Moon. The emplacement approach uses a gas-powered drill consisting of a >50 cm long, slim, hollow rod with a perforated anchor-cone at its lower end and the CCR mounted to the top. Gas supplied from a small tank is directed into and down the rod and out through the cone, lofting the soil out of the hole and allowing the rod to sink under its own weight to a depth of 0.5 m. To determine the system performance, we conducted several tests in compacted JSC-1a lunar soil simulant and inside a vacuum chamber. In several tests, the rod successfully sunk under its own weight of 16 N to a depth of 50 cm in 4-6 min. The pneumatic system is the game-changer for subsurface access. The extremely low mass and volume required to reach 50 cm, along with very simple penetration method allow the CCR to remain in a variety of payload architectures.

  16. Crossing the Salt Barrier

    Indian Academy of Sciences (India)

    Fry. RIVER. To cross the salt barrier is, therefore, an obligatory part of every amphihaline fish cycle. Figure 2a. Life Cycle of. Salmon. Adult salmon migrate from sea towards the river. After reaching their hatching ground, the eggs are laid in the gravel. The spawned fishes are called kelts. Alevin is a stage from hatching to fry.

  17. Great Barrier Reef

    Science.gov (United States)

    2002-01-01

    A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

  18. Effects of recharge wells and flow barriers on seawater intrusion.

    Science.gov (United States)

    Luyun, Roger; Momii, Kazuro; Nakagawa, Kei

    2011-01-01

    The installation of recharge wells and subsurface flow barriers are among several strategies proposed to control seawater intrusion on coastal groundwater systems. In this study, we performed laboratory-scale experiments and numerical simulations to determine the effects of the location and application of recharge wells, and of the location and penetration depth of flow barriers, on controlling seawater intrusion in unconfined coastal aquifers. We also compared the experimental results with existing analytical solutions. Our results showed that more effective saltwater repulsion is achieved when the recharge water is injected at the toe of the saltwater wedge. Point injection yields about the same repulsion compared with line injection from a screened well for the same recharge rate. Results for flow barriers showed that more effective saltwater repulsion is achieved with deeper barrier penetration and with barriers located closer to the coast. When the flow barrier is installed inland from the original toe position however, saltwater intrusion increases with deeper barrier penetration. Saltwater repulsion due to flow barrier installation was found to be linearly related to horizontal barrier location and a polynomial function of the barrier penetration depth. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  19. Indicators for Assessing Climate Change Resilience Resulting from Emplacement of Green Infrastructure Projects Across an Urban Landscape

    Science.gov (United States)

    Parish, E. S.; Omitaomu, O.; Sylvester, L.; Nugent, P.

    2015-12-01

    Many U.S. cities are exploring the potential of using green infrastructure (e.g., porous pavements, green roofs, street planters) to reduce urban storm water runoff, which can be both be a nuisance and costly to treat. While tools exist to measure local runoff changes resulting from individual green infrastructure (GI) projects, most municipalities currently have no method of analyzing the collective impact of GI projects on urban stormwater systems under future rainfall scenarios and impervious surface distribution patterns. Using the mid-sized city of Knoxville, Tennessee as a case study, we propose a set of indicators that can be used to monitor and analyze the collective effects of GI emplacement on urban storm water runoff volumes as well as to quantify potential co-benefits of GI projects (e.g., urban heat island reduction, reduced stream scouring) under different climate projection ensembles and population growth scenarios. These indicators are intended to help the city prioritize GI projects as opportunities arise, as well as to track the effectiveness of GI implementation over time. We explore the aggregation of these indicators across different spatial scales (e.g., plot, neighborhood, watershed, city) in order to assess potential changes in climate change resilience resulting from the collective implementation of GI projects across an urban landscape.

  20. Emplacement history and inflation evidence of a long basaltic lava flow located in Southern Payenia Volcanic Province, Argentina

    Science.gov (United States)

    Bernardi, Mauro I.; Bertotto, Gustavo W.; Jalowitzki, Tiago L. R.; Orihashi, Yuji; Ponce, Alexis D.

    2015-02-01

    The El Corcovo lava flow, from the Huanul shield volcano in the southern Mendoza province (central-western Argentina) traveled a distance of 70 km and covered a minimum area of ~ 415 km2. The flow emplacement was controlled both by extrinsic (e.g., topography) and intrinsic (e.g., lava supply rate, lava physicochemical characteristics) factors. The distal portion of the lava flow reached the Colorado River Valley, in La Pampa Province, where it spread and then was confined by earlier river channels. Cross-sections through the flow surveyed at several localities show two vesicular layers surrounding a dense central section, where vesicles are absent or clustered in sheet-shaped and cylindrical-shaped structures. Lavas of the El Corcovo flow are alkaline basalts with low values of viscosity. The morphological and structural characteristics of the flow and the presence of landforms associated with lava accumulation are the evidence of inflation. This process involved the formation of a tabular sheet flow up to 4 m of thick with a large areal extent in the proximal sectors, while at terminal sectors frontal lobes reached inflation values up to 10 m. The numerous swelling structures present at these portions of the flow suggest the movement of lava in lava tubes. We propose that this aspect and the low viscosity of the lava allowed the flow travel to a great distance on a gentle slope relief.

  1. Gravimetric and magnetic fabric study of the Sintra Igneous complex: laccolith-plug emplacement in the Western Iberian passive margin

    Science.gov (United States)

    Terrinha, Pedro; Pueyo, Emilio L.; Aranguren, Aitor; Kullberg, José Carlos; Kullberg, Maria Carla; Casas-Sainz, Antonio; Azevedo, Maria do Rosário

    2017-12-01

    The geometry and emplacement of the 96 km2, Late Cretaceous Sintra Igneous complex (SIC, ca. 80 Ma) into the West Iberian passive margin is presented, based on structural data, gravimetric modeling, and magnetic fabrics. A granite laccolith ( 76 km2, deformation in most part of the massif. Magnetic foliations are shallowly dipping in the granite laccolith and contain a sub-horizontal ENE-WSW lineation. The gabbro-syenite body displays concentric magnetic foliations having variable dips and steeply-plunging lineations. The SIC can be interpreted to be intruded along an NNW-SSE, 200 km-long fault, perpendicular to the magnetic lineation within the laccolith, and was preceded by the intrusion of basic sills and plugs. The SIC intruded the Mesozoic series of the Lusitanian Basin during the post-rift, passive margin stage, and its geometry was only slightly modified during the Paleogene inversion that resulted in thrusting of the northern border of the intrusion over the country rocks.

  2. Sound trapping and dredging barriers.

    Science.gov (United States)

    Wang, Xu; Wang, Xiaonan; Yu, Wuzhou; Jiang, Zaixiu; Mao, Dongxing

    2017-06-01

    When sound barriers are installed on both sides of a noise source, degradation in performance is observed. Barriers having negative-phase-gradient surfaces successfully eliminate this drawback by trapping sound energy in between the barriers. In contrast, barriers can also be designed to "dredge" the energy flux out. An extended model considering higher-order diffractions, which resulted from the interplay of the induced surface wave and barrier surface periodicity, is presented. It is found that the sound dredging barriers provide a remarkable enhancement over the trapping ones, and hence have the potential to be widely used in noise control engineering.

  3. Nevada Nuclear Waste Storage Investigations Project: thermal analysis of spent fuel disposal in vertical emplacement boreholes in a welded tuff repository

    International Nuclear Information System (INIS)

    St John, C.M.

    1985-11-01

    Two- and three-dimensional heat transfer analyses were conducted to determine temperatures in the vicinity of a waste canister and an emplacement drift. The effect of emplacement of canisters containing spent fuel in vertical boreholes was simulated for the cases of an emplacement drift either fully ventilated or sealed immediately after canister emplacement. PORFLOW and THERM3D respectively solve the two- and three-dimensional forms of the diffusion equation. In the unventilated case, the effect of radiation was approximated by defining an equivalent radiation thermal conductivity. A simple code, TEMP3D, based on the closed form solutions for constant and decaying heat sources, was also used. Calculations indicate that the temperature at the canister borehole wall will peak at about 215 0 C if the drift is ventilated and about 240 0 C if it is unventilated. The peak temperature occurs sooner in the ventilated case; after 3 to 4 yr versus 9 yr. For a point 1 m from the wall of the emplacement borehole, the corresponding peak temperatures are 150 0 C for the ventilated case and 185 0 C for the unventilated case and occur at about 5 and 17 yr. We assumed that the effect of drift ventilation would be to maintain a uniform temperature of 30 0 C at the drift perimeter. If the drift is unventilated the wall rock temperature peaks some 75 to 100 yr after waste emplacement; reaching about 125 0 C at the mid-height of the drift wall. Comparisons between the results of the three-dimensional analyses performed using TEMP3D and THERM3D indicated that the simpler modeling technique provided a good estimate of temperatures in the immediate vicinity of the canister for both the ventilated and unventilated cases. Comparisons of the results of two- and three-dimensional analyses performed using the PORFLOW and THERM3D codes indicated that the two-dimensional approximation is excellent, except in the immediate vicinity of the canister

  4. An extreme breaching of a barrier spit: insights on large breach formation and its impact on barrier dynamics

    Science.gov (United States)

    Iulian Zăinescu, Florin; Vespremeanu-Stroe, Alfred; Tătui, Florin

    2017-04-01

    In this study, we document a case of exceptionally large natural breaching of a sandy spit (Sacalin barrier, Danube delta) using Lidar data and satellite imagery, annual (and seasonal) surveys of topography and bathymetry on successive cross-barrier profiles, and hourly datasets of wind and waves. The breach morphology and dynamics was monitored and described from its inception to closure, together with its impact on the adjoining features (upper shoreface, back-barrier lagoon, downdrift coast) and on the local sediment budgets. Breaching is first observed to occur on a beach-length of 0.5 km in April 2012 and two years later reached 3.5 km (May 2014). The barrier translates to a recovery stage dominated by continuous back-barrier deposition through subaqueous cross-breach sediment transport. Soon, the barrier widening triggers a negative feedback which limits the back-barrier sediment transfer. As a result, back-barrier deposition decreases whilst the barrier aggradation through overwash becomes more frequent. The event was found to be a natural experiment which switched the barrier's decadal evolution from low cross-shore transport to high cross-shore transport over the barrier. Although previously considered as constant, the cross-shore transport recorded during the large breach lifespan is an order of magnitude larger than in the non-breach period. 3 x 106 m3 of sediment were deposited in three years which is equivalent to the modelled longshore transport in the region. Nevertheless, the sediment circuits are more complex involving exchanges with the upper shoreface, as indicated by the extensive erosion down to -4m. In the absence of tides, the Sacalin breach closed naturally in 3 years and brings a valuable contribution on how breaches may evolve, as only limited data has been internationally reported until now. The very high deposition rate of sediment in the breach is a testimony of the high sediment volumes supplied by the longshore transport and the high

  5. Visual selective attention with virtual barriers.

    Science.gov (United States)

    Schneider, Darryl W

    2017-07-01

    Previous studies have shown that interference effects in the flanker task are reduced when physical barriers (e.g., hands) are placed around rather than below a target flanked by distractors. One explanation of this finding is the referential coding hypothesis, whereby the barriers serve as reference objects for allocating attention. In five experiments, the generality of the referential coding hypothesis was tested by investigating whether interference effects are modulated by the placement of virtual barriers (e.g., parentheses). Modulation of flanker interference was found only when target and distractors differed in size and the virtual barriers were beveled wood-grain objects. Under these conditions and those of previous studies, the author conjectures that an impression of depth was produced when the barriers were around the target, such that the target was perceived to be on a different depth plane than the distractors. Perception of depth in the stimulus display might have led to referential coding of the stimuli in three-dimensional (3-D) space, influencing the allocation of attention beyond the horizontal and vertical dimensions. This 3-D referential coding hypothesis is consistent with research on selective attention in 3-D space that shows flanker interference is reduced when target and distractors are separated in depth.

  6. Surface stability test plan for protective barriers

    International Nuclear Information System (INIS)

    Ligotke, M.W.

    1989-01-01

    Natural-material protective barriers for long-term isolation of buried waste have been identified as integral components of a plan to isolate a number of Hanford defense waste sites. Standards currently being developed for internal and external barrier performance will mandate a barrier surface layer that is resistant to the eolian erosion processes of wind erosion (deflation) and windborne particle deposition (formation of sand dunes). Thus, experiments are needed to measure rates of eolian erosion processes impacting those surfaces under different surface and climatological conditions. Data from these studies will provide information for use in the evaluation of selected surface layers as a means of providing stable cover over waste sites throughout the design life span of protective barriers. The multi-year test plan described in this plan is directed at understanding processes of wind erosion and windborne particle deposition, providing measurements of erosion rates for models, and suggesting construction materials and methods for reducing the effect of long-term eolian erosion on the barrier. Specifically, this plan describes possible methods to measure rates of eolian erosion, including field and laboratory procedure. Advantages and disadvantages of laboratory (wind tunnel) tests are discussed, and continued wind tunnel tests are recommended for wind erosion studies. A comparison between field and wind tunnel erosive forces is discussed. Plans for testing surfaces are described. Guidance is also presented for studying the processes controlling sand dune and blowout formation. 24 refs., 7 figs., 3 tabs

  7. Relationship between encapsulation barrier performance and organic solar cell lifetime

    Science.gov (United States)

    Cros, Stéphane; Guillerez, Stéphane; de Bettignies, Rémi; Lemaître, Noëlla; Bailly, Severine; Maisse, Pascal

    2008-08-01

    This article describes a method to have a better knowledge of barrier performances needed for encapsulating materials, particularly in the case of organic solar cells devices. We have developed a high sensitivity permeameter which enables simultaneous measurements of water and oxygen permeation. Various polymers and inorganic coatings on polymer substrates have been measured. Experimental barrier parameters have been plotted considering the steady and transient states of permeation curves and compared to theoretical values. In addition, we have performed ageing experiments on encapsulated organic solar cells to establish a barrier requirement directly related to the device. Finally, we have performed such experiments using different cathode materials and encapsulating materials.

  8. Apoplastic Diffusion Barriers in Arabidopsis

    Science.gov (United States)

    Schreiber, Lukas; Franke, Rochus Benni; Geldner, Niko; Reina-Pinto, José J.; Kunst, Ljerka

    2013-01-01

    During the development of Arabidopsis and other land plants, diffusion barriers are formed in the apoplast of specialized tissues within a variety of plant organs. While the cuticle of the epidermis is the primary diffusion barrier in the shoot, the Casparian strips and suberin lamellae of the endodermis and the periderm represent the diffusion barriers in the root. Different classes of molecules contribute to the formation of extracellular diffusion barriers in an organ- and tissue-specific manner. Cutin and wax are the major components of the cuticle, lignin forms the early Casparian strip, and suberin is deposited in the stage II endodermis and the periderm. The current status of our understanding of the relationships between the chemical structure, ultrastructure and physiological functions of plant diffusion barriers is discussed. Specific aspects of the synthesis of diffusion barrier components and protocols that can be used for the assessment of barrier function and important barrier properties are also presented. PMID:24465172

  9. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, horizontal emplacment mode: Volume 1

    International Nuclear Information System (INIS)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packaging, and other surface facility operations are described. Operations in the shafts and underground are described, including waste hoisting, transfer, and horizontal emplacement. This report specifically addresses the horizontal emplacement mode, the passive alternate design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs

  10. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 1

    International Nuclear Information System (INIS)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packing, and other surface facility operations are described. Operations in the shafts underground are described, including waste hoisting, transfer, and vertical emplacement. This report specifically addresses the vertical emplacement mode, the reference design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs

  11. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository: accident event analysis and mechanical failure probabilities. Final report

    International Nuclear Information System (INIS)

    Bhaskaran, G.; McCleery, J.E.

    1979-10-01

    This report provides support in developing an accident prediction event tree diagram, with an analysis of the baseline design concept for the retrieval of emplaced spent unreprocessed fuel (SURF) contained in a degraded Canister. The report contains an evaluation check list, accident logic diagrams, accident event tables, fault trees/event trees and discussions of failure probabilities for the following subsystems as potential contributors to a failure: (a) Canister extraction, including the core and ram units; (b) Canister transfer at the hoist area; and (c) Canister hoisting. This report is the second volume of a series. It continues and expands upon the report Retrieval System for Emplaced Spent Unreprocessed Fuel (SURF) in Salt Bed Depository: Baseline Concept Criteria Specifications and Mechanical Failure Probabilities. This report draws upon the baseline conceptual specifications contained in the first report

  12. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository: accident event analysis and mechanical failure probabilities. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, G.; McCleery, J.E.

    1979-10-01

    This report provides support in developing an accident prediction event tree diagram, with an analysis of the baseline design concept for the retrieval of emplaced spent unreprocessed fuel (SURF) contained in a degraded Canister. The report contains an evaluation check list, accident logic diagrams, accident event tables, fault trees/event trees and discussions of failure probabilities for the following subsystems as potential contributors to a failure: (a) Canister extraction, including the core and ram units; (b) Canister transfer at the hoist area; and (c) Canister hoisting. This report is the second volume of a series. It continues and expands upon the report Retrieval System for Emplaced Spent Unreprocessed Fuel (SURF) in Salt Bed Depository: Baseline Concept Criteria Specifications and Mechanical Failure Probabilities. This report draws upon the baseline conceptual specifications contained in the first report.

  13. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packing, and other surface facility operations are described. Operations in the shafts underground are described, including waste hoisting, transfer, and vertical emplacement. This report specifically addresses the vertical emplacement mode, the reference design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs.

  14. Performance of engineered barriers

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  15. Dome collapse mechanisms and block-and-ash flow emplacement dynamics inferred from deposit and impact mark analysis, Mono Craters, CA

    OpenAIRE

    Dennen, R. L.; Bursik, M. I.; Roche, Olivier

    2014-01-01

    Characteristics of the Panum block-and-ash flow (BAF) deposit, Mono Craters, CA, were analyzed to determine the mechanisms of collapse of the parent dome and dynamics of emplacement of the BAF. Granulometry, componentry, and obsidian water content data were used to define distinct facies of the Panum BAF deposit. These suggest a sequential, three-stage collapse model for the ancestral dome of the Panum vent, with destabilization first of its cold, brittle outer margins and then of its hot, du...

  16. The Jeffers Brook diorite-granodiorite pluton: style of emplacement and role of volatiles at various crustal levels in Avalonian appinites, Canadian Appalachians

    Science.gov (United States)

    Pe-Piper, Georgia; Piper, David J. W.

    2018-04-01

    Small appinite plutons ca. 610 Ma outcrop in the peri-Gondwanan Avalon terrane of northern Nova Scotia, with different structural levels exposed. Field mapping shows that the Jeffers Brook pluton is a laccolith emplaced along an upper crustal thrust zone, likely in a dilational jog in a regional dextral strike-slip system. The oldest rocks are probably mafic sills, which heated the area facilitating emplacement of intermediate magmas. Cross-cutting relationships show that both mafic and intermediate magmas were supplied throughout the history of pluton emplacement. The modal composition, mineral chemistry, and bulk chemistry of gabbro, diorite, tonalite, granodiorite, and granite have been studied in the main plutonic phases, dykes, and sills, and mafic microgranular enclaves. As with the type appinites in the Scottish Caledonides, the pluton shows evidence of high water content: the dominance of hornblende, locally within pegmatitic texture; vesicles and irregular felsic patches in enclaves; and late aplite dykes. Analyzed mafic microgranular enclaves are geochemically similar to larger diorite bodies in the pluton. Tonalite-granodiorite is distinct from the diorite in trace-element geochemistry and radiogenic isotopes. Elsewhere to the east, similar rocks of the same age form vertically sheeted complexes in major shear zones; hornblende chemistry shows that they were emplaced at a deeper upper crustal level. This implies that little of the observed geochemical variability in the Jeffers Brook pluton was developed within the pluton. The general requirements to form appinites are proposed to be small magma volumes of subduction-related magmas that reach the upper crust because of continual heating by mafic magmas moving through strike-slip fault pathways and trapping of aqueous fluids rather than venting through volcanic activity.

  17. Expectations of barriers to psychosocial care : Views of parents and adolescents in the community

    NARCIS (Netherlands)

    Nanninga, Marieke; Reijneveld, Sijmen A; Knorth, Erik J; Jansen, Danielle E M C

    Parents with a child suffering from psychosocial problems frequently experience barriers to psychosocial care, which may hinder access. Expectations of barriers may have the same effect, but evidence is lacking. The aim of this study is to examine parents' and adolescents' expectations of barriers

  18. Radiometric, magnetic, and gravity study of the Quixadá batholith, central Ceará domain (NE Brazil): evidence for Pan-African/Brasiliano extension-controlled emplacement

    Science.gov (United States)

    Lopes de Castro, David; Mariano Gomes Castelo Branco, Raimundo; Martins, Guttenberg; Araújo de Castro, Neivaldo

    2002-10-01

    A geophysical survey was conducted in the central Ceará domain of the Borborema Province (NE Brazil). The aim of this investigation was to find geophysical evidence for the emplacement of the Quixadá batholith, which is a granitic body probably situated in the local extensional site in the oblique collisional regime of the Pan-African/Brasiliano collage. Remote sensing and airborne geophysical data provided information on the regional deformation that affected the intrusion and surrounding country rocks. In addition, a gravity study was used to determine the three-dimensional geometry and constrain the emplacement model of the Quixadá granite at depth. The trajectories of structural and magnetic lineaments suggest that the regional deformation is strongly influenced by dextral transcurrent movements of the major shear zones. The batholith, which shows an unusual positive gravity anomaly and a low U counts, displays a subhorizontal floor with several gently dipping areas, which are interpreted as magma feeder channels. The 2300 m thick root zones are roughly aligned with NE-SW-trending shear zones. Finally, the internal architecture of the pluton suggests that the Quixadá batholith was emplaced in a dilational shear zone tip area at the north end of Quixeramobim shear zone.

  19. Tracking lava flow emplacement on the east rift zone of Kīlauea, Hawai‘i, with synthetic aperture radar coherence

    Science.gov (United States)

    Dietterich, Hannah R.; Poland, Michael P.; Schmidt, David A.; Cashman, Katharine V.; Sherrod, David R.; Espinosa, Arkin Tapia

    2012-05-01

    Lava flow mapping is both an essential component of volcano monitoring and a valuable tool for investigating lava flow behavior. Although maps are traditionally created through field surveys, remote sensing allows an extraordinary view of active lava flows while avoiding the difficulties of mapping on location. Synthetic aperture radar (SAR) imagery, in particular, can detect changes in a flow field by comparing two images collected at different times with SAR coherence. New lava flows radically alter the scattering properties of the surface, making the radar signal decorrelated in SAR coherence images. We describe a new technique, SAR Coherence Mapping (SCM), to map lava flows automatically from coherence images independent of look angle or satellite path. We use this approach to map lava flow emplacement during the Pu`u `Ō`ō-Kupaianaha eruption at Kīlauea, Hawai`i. The resulting flow maps correspond well with field mapping and better resolve the internal structure of surface flows, as well as the locations of active flow paths. However, the SCM technique is only moderately successful at mapping flows that enter vegetation, which is also often decorrelated between successive SAR images. Along with measurements of planform morphology, we are able to show that the length of time a flow stays decorrelated after initial emplacement is linearly related to the flow thickness. Finally, we use interferograms obtained after flow surfaces become correlated to show that persistent decorrelation is caused by post-emplacement flow subsidence.

  20. The Relative Effectiveness of Empirical and Physical Models for Simulating the Dense Undercurrent of Pyroclastic Flows under Different Emplacement Conditions

    Directory of Open Access Journals (Sweden)

    Sarah E. Ogburn

    2017-11-01

    Full Text Available High concentration pyroclastic density currents (PDCs are hot avalanches of volcanic rock and gas and are among the most destructive volcanic hazards due to their speed and mobility. Mitigating the risk associated with these flows depends upon accurate forecasting of possible impacted areas, often using empirical or physical models. TITAN2D, VolcFlow, LAHARZ, and ΔH/L or energy cone models each employ different rheologies or empirical relationships and therefore differ in appropriateness of application for different types of mass flows and topographic environments. This work seeks to test different statistically- and physically-based models against a range of PDCs of different volumes, emplaced under different conditions, over different topography in order to test the relative effectiveness, operational aspects, and ultimately, the utility of each model for use in hazard assessments. The purpose of this work is not to rank models, but rather to understand the extent to which the different modeling approaches can replicate reality in certain conditions, and to explore the dynamics of PDCs themselves. In this work, these models are used to recreate the inundation areas of the dense-basal undercurrent of all 13 mapped, land-confined, Soufrière Hills Volcano dome-collapse PDCs emplaced from 1996 to 2010 to test the relative effectiveness of different computational models. Best-fit model results and their input parameters are compared with results using observation- and deposit-derived input parameters. Additional comparison is made between best-fit model results and those using empirically-derived input parameters from the FlowDat global database, which represent “forward” modeling simulations as would be completed for hazard assessment purposes. Results indicate that TITAN2D is able to reproduce inundated areas well using flux sources, although velocities are often unrealistically high. VolcFlow is also able to replicate flow runout well, but

  1. Monitoring Inflation and Emplacement During the 2014-2015 Kilauea Lava Flow With an Unmanned Aerial Vehicle

    Science.gov (United States)

    Perroy, R. L.; Turner, N.; Hon, K. A.; Rasgado, V.

    2015-12-01

    Unmanned aerial vehicles (UAVs) provide a powerful new tool for collecting high resolution on-demand spatial data over volcanic eruptions and other active geomorphic processes. These data can be used to improve hazard forecasts and emergency response efforts, and also allow users to economically and safely observe and quantify lava flow inflation and emplacement on spatially and temporally useful scales. We used a small fixed-wing UAV with a modified point-and-shoot camera to repeatedly map the active front of the 2014-2015 Kīlauea lava flow over a one-month period in late 2014, at times with a two-hour repeat interval. An additional subsequent flight was added in July, 2015. We used the imagery from these flights to generate a time-series of 5-cm resolution RGB and near-infrared orthoimagery mosaics and associated digital surface models using structure from motion. Survey-grade positional control was provided by ground control points with differential GPS. Two topographic transects were repeatedly surveyed across the flow surface, contemporaneously with UAV flights, to independently confirm topographic changes observed in the UAV-derived surface models. Vertical errors were generally 10 cm. Inside our 50 hectare study site, the flow advanced at a rate of 0.47 hectares/day during the first three weeks of observations before abruptly stalling out 4 m. New outbreak areas, both on the existing flow surface and along the flow margins, were readily mapped across the study area. We detected sinuous growing inflation ridges within the flow surface that correlated with subsequent outbreaks of new lava, suggesting that repeat UAV flights can provide a means of better predicting pahoehoe lava flow behavior over flat or uneven topography. Our results show that UAVs can generate accurate and digital surface models quickly and inexpensively over rapidly changing active pahoehoe lava flows.

  2. PRIORITISING LEAN CONSTRUCTION BARRIERS IN UGANDA'S CONSTRUCTION INDUSTRY

    Directory of Open Access Journals (Sweden)

    Henry Mwanaki Alinaitwe

    2009-06-01

    Full Text Available Engaging in lean construction efforts could prove to be highly rewarding for building firms in Uganda. However, lean construction is risky and can be disastrous if not properly managed. Lean production efforts in some other countries have not been successful due to the many barriers to its successful implementation. To enable sound lean construction efforts and to increase the chances of success in eliminating waste, a thorough investigation of the barriers is essential. This study presents 31 barriers and investigates their influence (strength on the success of lean construction initiatives. Structured interviews were carried out with technical managers of building firms to assess their perception of the barriers to lean production based on their experience at their firms. The strongest barrier is the provision of inputs exactly when required. Additionally, the barriers were ranked according to the ease of overcoming each. The easiest barrier to overcome is keeping the required items in the right place. Finally, a graphical aid is provided to enable decision makers to concentrate their efforts on the influential (strong, yet easy to overcome barriers. A lack of buildable designs and a participative management style for the workforce are the most important barriers to successful waste reduction in terms of strength and ease of overcoming. On the other hand, a lack of an organisational culture that supports teamwork, a lack of prefabrication and a lack of knowledgeable and skilled workers are regarded as low in strength, and at the same time difficult to overcome.

  3. The Wall-Rock Record of Incremental Emplacement in the Little Cottonwood-Alta Magmatic and Hydrothermal System, Wasatch Mountains, Utah, U.S.A.

    Science.gov (United States)

    Stearns, M.; Callis, S.; Beno, C.; Bowman, J. R.; Bartley, J. M.

    2017-12-01

    Contact aureoles record the cumulative effects on wall rocks of magma emplacement. Like the plutons they surround, contact aureoles have long been regarded to form geologically instantaneously. Protracted incremental emplacement of plutons must be reconciled with the wall-rock record of heat and mass transfer. Fundamental questions include how heat and material move from intrusions into their aureoles and how long that process takes. The Little Cottonwood stock is surrounded by a 2 km-wide contact aureole that contains prograde AFM mineral assemblages in the pelitic layers of the Proterozoic Big Cottonwood Formation. The Alta stock is surrounded by a well characterized 1 km-wide contact aureole containing both prograde AFM and CMS mineral assemblages in Ophir Shale and Mississippian dolostones, respectively. Understanding the petrogenesis of these aureoles requires the timing of magmatism and wall-rock metamorphism to be independently determined. Preliminary petrochronology (U/Th-Pb dates and trace element concentrations collected by LASS-ICP-MS) from the inner aureoles of both intrusions establishes a protracted history of monazite (re)crystallization from 35-25 Ma in the Little Cottonwood aureole and 35 Ma in the Alta aureole. Little Cottonwood aureole monazites are characterized by a positive age correlation with heavy rare earth elements (HREE) and a negative correlation with Eu/Eu*. Alta aureole monazites have a similar range of the HREE concentrations and Eu/Eu* variation. Zircon growth interpreted to record emplacement-level magmatic crystallization of the western Little Cottonwood stock ranges from 33-28 Ma near the contact. Multi-grain U-Pb zircon TIMS dates from the Alta stock range from 35-33 Ma and are interpreted to suggest the full range of emplacement-level magmatism in the Alta stock. Additionally, in situ U-Pb titanite dates from the Alta stock record intermittent high temperature hydrothermal activity in the stock margin from 35-24 Ma. These new

  4. 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.

  5. Explosive performance on the non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    McKown, T.O.

    1994-03-01

    The non-proliferation experiment, originally called the chemical kiloton experiment, was planned and executed by Lawrence Livermore National Laboratory to investigate the seismic yield relationship and distinguishing seismic signals between a nuclear event and a large mass conventional explosion. The Los Alamos National Laboratory planned and conducted experiments to further their studies of the source function for signals observed seismically. Since all investigations were contingent on the performance of the emplaced chemical explosive, an array of diagnostic measurements was fielded in the emplaced explosive. The CORRTEX system was used to investigate the explosive initiation and to determine the detonation velocities in multiple levels and in numerous directions. A description of the CORRTEX experiments fielded, a review of the data obtained and some interpretations of the data are reported.

  6. Dynamic simulation of collisions of heavy high-speed trucks with concrete barriers

    International Nuclear Information System (INIS)

    Itoh, Yoshito; Liu, Chunlu; Kusama, Ryuichi

    2007-01-01

    Real vehicle collision experiments on full-scale road safety barriers are important to determine the outcome of a vehicle versus barrier impact accident. However, such experiments require large investment of time and money. Numerical simulation has therefore been imperative as an alternative method for testing concrete barriers. In this research, spring subgrade models were first developed to simulate the ground boundary of concrete barriers. Both heavy trucks and concrete barriers were modeled using finite element methods (FEM) to simulate dynamic collision performances. Comparison of the results generated from computer simulations and on-site full-scale experiments demonstrated that the developed models could be applied to simulate the collision of heavy trucks with concrete barriers to provide the data to design new road safety barriers and analyze existing ones

  7. Linguistic Barriers and Bridges

    DEFF Research Database (Denmark)

    Thuesen, Frederik

    2016-01-01

    The influence of language on social capital in low-skill and ethnically diverse workplaces has thus far received very limited attention within the sociology of work. As the ethnically diverse workplace is an important social space for the construction of social relations bridging different social...... and intercultural communication, this article analyses interviews with 31 employees from two highly ethnically diverse Danish workplaces. The article shows how linguistic barriers such as different levels of majority language competence and their consequent misunderstandings breed mistrust and hostility, whilst...... communication related to collaboration and ‘small talk’ may provide linguistic bridges to social capital formation....

  8. [Barrier methods of contraception].

    Science.gov (United States)

    Goldsmith, A; Edelman, D A

    1982-01-01

    Vaginal methods of contraception were the earliest types used and some references to them date back to antiquity. Most of the vaginal contraceptive agents identified by the ancient Greeks, Indians, Japanese, and Chinese have been found in modern laboratory tests to have spermicidal properties, but it is doubtful that the methods were fully reliable or were used by many people. During the 19th century the condom, vaginal spermicides, and diaphragm became available. The development of nonoxynol-9 and other nonirritating but effective spermicidal agents improved vaginal contraceptives greatly by the 1950s, but starting in the 1960s newer methods began to replace the vaginal methods. Interest in barrier methods has been reawakened somewhat by concern about the health effects of hormonal methods. At present all barrier methods leave something to be desired. Failure rates of 3-30% for barrier methods in general have been estimated, but the higher rates are believed due to incorrect or inconsistent use. Theoretical failure rates of condoms and diaphragms have been estimated at 3/100 women-years, but in actual use failure rates may reach 15 for condoms and 13 for diaphragms used with spermicides. Use-effectiveness rates are greatly influenced by motivation. For a variety of reasons, the acceptability of barrier methods is low, especially in developing countries. New developments in spermicidal agents include sperm inhibitors, which impede the fertilizing capacity of sperm rather than attempting a spermicidal effect; a number of such agents have been studied and have proven more effective in animal tests than conventional spermicides. Neosampoon, a new spermicidal foam, has attracted an increasing number of users, especially in developing countries. A new condom, made of thin polymers and containing a standard dose of nonoxynol-9, has been designed to dissolve in the vaginal fluid. Further studies are needed of its acceptability, efficacy, and side effects before it becomes

  9. Support or Barrier?

    DEFF Research Database (Denmark)

    Sanden, Guro Refsum; Lønsmann, Dorte

    employees use to cross language boundaries in their everyday work, and, secondly, how these practices relate to top-down language management in the case companies. Our findings show that employees are often dependent on ad hoc and informal solutions in cross- language situations, which leads us......This study offers a critical look at how corporate-level language management influences front-line language practices among employees in three multinational corporations (MNCs) headquartered in Scandinavia. Based on interview and document data, we examine, firstly, what front-line practices...... to a discussion of how a company’s language policy may be seen as both support and a barrier....

  10. Examples of storm impacts on barrier islands: Chapter 4

    Science.gov (United States)

    Plant, Nathaniel G.; Doran, Kara; Stockdon, Hilary F.

    2017-01-01

    This chapter focuses on the morphologic variability of barrier islands and on the differences in storm response. It describes different types of barrier island response to individual storms, as well as the integrated response of barrier islands to many storms. The chapter considers case study on the Chandeleur Island chain, where a decadal time series of island elevation measurements have documented a wide range of barrier island responses to storms and long-term processes that are representative of barrier island behaviour at many other locations. These islands are low elevation, extremely vulnerable to storms and exhibit a diversity of storm responses. Additionally, this location experiences a moderately high rate of relative sea-level rise, increasing its vulnerability to the combined impacts of storms and long-term erosional processes. Understanding how natural processes, including storm impacts and intervening recovery periods interact with man-made restoration processes is also broadly relevant to understand the natural and human response to future storms.

  11. Trends and barriers to lateral gene transfer in prokaryotes.

    Science.gov (United States)

    Popa, Ovidiu; Dagan, Tal

    2011-10-01

    Gene acquisition by lateral gene transfer (LGT) is an important mechanism for natural variation among prokaryotes. Laboratory experiments show that protein-coding genes can be laterally transferred extremely fast among microbial cells, inherited to most of their descendants, and adapt to a new regulatory regime within a short time. Recent advance in the phylogenetic analysis of microbial genomes using networks approach reveals a substantial impact of LGT during microbial genome evolution. Phylogenomic networks of LGT among prokaryotes reconstructed from completely sequenced genomes uncover barriers to LGT in multiple levels. Here we discuss the kinds of barriers to gene acquisition in nature including physical barriers for gene transfer between cells, genomic barriers for the integration of acquired DNA, and functional barriers for the acquisition of new genes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Summary report on close-coupled subsurface barrier technology: Initial field trials to full-scale demonstration

    International Nuclear Information System (INIS)

    Heiser, J.H.

    1997-09-01

    The primary objective of this project was to develop and demonstrate the installation and measure the performance of a close-coupled barrier for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional, low-cost, cement-grout containment barrier followed by a thin lining of a polymer grout. The resultant barrier is a cement-polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. The technology has matured from a regulatory investigation of the issues concerning the use of polymers to laboratory compatibility and performance measurements of various polymer systems to a pilot-scale, single column injection at Sandia to full-scale demonstration. The feasibility of the close-coupled barrier concept was proven in a full-scale cold demonstration at Hanford, Washington and then moved to the final stage with a full-scale demonstration at an actual remediation site at Brookhaven National Laboratory (BNL). At the Hanford demonstration the composite barrier was emplaced around and beneath a 20,000 liter tank. The secondary cement layer was constructed using conventional jet grouting techniques. Drilling was completed at a 45 degree angle to the ground, forming a cone-shaped barrier. The primary barrier was placed by panel jet-grouting with a dual-wall drill stem using a two part polymer grout. The polymer chosen was a high molecular weight acrylic. At the BNL demonstration a V-trough barrier was installed using a conventional cement grout for the secondary layer and an acrylic-gel polymer for the primary layer. Construction techniques were identical to the Hanford installation. This report summarizes the technology development from pilot- to full-scale demonstrations and presents some of the performance and quality achievements attained

  13. Summary report on close-coupled subsurface barrier technology: Initial field trials to full-scale demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Heiser, J.H. [Brookhaven National Lab., Upton, NY (United States). Environmental and Waste Technology Center; Dwyer, B. [Sandia National Lab., Albuquerque, NM (United States)

    1997-09-01

    The primary objective of this project was to develop and demonstrate the installation and measure the performance of a close-coupled barrier for the containment of subsurface waste or contaminant migration. A close-coupled barrier is produced by first installing a conventional, low-cost, cement-grout containment barrier followed by a thin lining of a polymer grout. The resultant barrier is a cement-polymer composite that has economic benefits derived from the cement and performance benefits from the durable and resistant polymer layer. The technology has matured from a regulatory investigation of the issues concerning the use of polymers to laboratory compatibility and performance measurements of various polymer systems to a pilot-scale, single column injection at Sandia to full-scale demonstration. The feasibility of the close-coupled barrier concept was proven in a full-scale cold demonstration at Hanford, Washington and then moved to the final stage with a full-scale demonstration at an actual remediation site at Brookhaven National Laboratory (BNL). At the Hanford demonstration the composite barrier was emplaced around and beneath a 20,000 liter tank. The secondary cement layer was constructed using conventional jet grouting techniques. Drilling was completed at a 45{degree} angle to the ground, forming a cone-shaped barrier. The primary barrier was placed by panel jet-grouting with a dual-wall drill stem using a two part polymer grout. The polymer chosen was a high molecular weight acrylic. At the BNL demonstration a V-trough barrier was installed using a conventional cement grout for the secondary layer and an acrylic-gel polymer for the primary layer. Construction techniques were identical to the Hanford installation. This report summarizes the technology development from pilot- to full-scale demonstrations and presents some of the performance and quality achievements attained.

  14. 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.

  15. 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.

  16. Postorogenic emplacement of the Santa Marta Batholith, northwestern flank of the Sierra Nevada de Santa Marta (SNSM).

    Science.gov (United States)

    Sanchez Sierra, Johan Miguel Sebastian; Kammer, Andreas

    2017-04-01

    The Santa Marta Batholith (BSM) belongs to a Paleogene intrusive suite of the Santa Marta massif, an exhumed triangular block at the southern Caribbean margin. Its Paleogene age precludes its association to an active margin, although its emplacement was controlled by the flexure of the down-bent Southamerican plate. Its internal structure is outlined by a mafic border facies and a felsic core, both having a petrologic affinity to a TTG-suite. According to existing age data, the BSM consolidated sequentially from SW to NE, with a first pulse having crystallized at 56 Ma in the southern domain and a final pulse in the northern domain at 52-50 Ma. Pressures varied between 5-7 kb, corresponding to depths of 14-19 km. This study combines structural, thermochronological and geochemical data with an analysis of Anisotropy and Magnetic Susceptibility (AMS) and paleomagnetism. The SNSM had a clockwise rotation of 30 ° and the ASM results help distinguish between two fault-bounded structural domains. The southern domain is characterized by a magnetic foliation concordant to the contact of the host rock that dips toward the hinterland. The northern domain, in contrast, displays a N-S trending magnetic foliation that is oblique to the regional structural northeastern trend. This divergence is supported by the orientation of mineral lineations, enclaves and dikes. In spite of its arc signature, anomalies like enrichment in Ti, depletion of Nb-Ta and Zr-Hf, as well as flat REE patterns can be associated to the accumulation of crystallized mafic minerals from less-fractionated magmas. These data evidence mingling. Asymmetric internal organization, as indicated by a hinterland-dipping roof pendent, the structural setting at the margin of a thickened continental margin and its geochemical signature favor a scenario of a magma generation at a mid-crustal level and its consequent extrusion along a channel, that connected to the crustal bend of the continental plate that was

  17. Emplacement dynamics and timescale of a Holocene flow from the Cima Volcanic Field (CA): Insights from rheology and morphology

    Science.gov (United States)

    Soldati, Arianna; Beem, Jordon; Gomez, Francisco; Huntley, John Warren; Robertson, Timothy; Whittington, Alan

    2017-11-01

    We present a rheological and morphological study of a Holocene lava flow emitted by a monogenetic cinder cone in the Cima Volcanic Field, eastern California. Our field observations focused on surface morphology, which transitions from smooth core extrusions near the vent to jagged 'a'ā blocks over the majority of the flow, and on channel and levée dimensions. We collected airborne photogrammetry data and used it to generate a digital elevation model. From this, the total flow volume was estimated and surface roughness was quantified in terms of standard deviation of the real surface (5 cm resolution) from the software-generated 1 m-average plane. Sample textural analyses revealed that the near-vent portion of the flow is significantly more crystalline (ϕxtal = 0.95 ± 0.04) than the main flow body (ϕxtal = 0.66 ± 0.11). The rheology of Cima lavas was determined experimentally by concentric cylinder viscometry between 1550 °C and 1160 °C, including the first subliquidus rheology measurements for a continental intraplate trachybasaltic lava. The experimentally determined effective viscosity increases from 54 Pa·s to 1361 Pa·s during cooling from the liquidus ( 1230 °C) to 1160 °C, where crystal fraction is 0.11. The lava viscosity over this range is still lower than most basaltic melts, due to the high alkali content of Cima lavas ( 6 wt% Na2O + K2O). Monte Carlo simulations were used to account for and propagate experimental uncertainties, and to determine which rheological model (Bingham, power law, or Herschel-Bulkley) provides the best-fit of the obtained rheological data. Results suggest that Bingham and Herschel-Bulkley models are statistically indistinguishable from each other, and that both fit the data better than a power law model. By combining field observations and experimental results, we reconstructed the eruption temperature and few days-long emplacement history of the Cima flow.

  18. Ship Rock Diatreme: is it a Classical Volcano? New Evidence on Magma Ascent and Emplacement Within the Navajo Volcanic Field

    Science.gov (United States)

    Rotzien, J. R.; Mayhew, B.; Yospin, S.; Beiki, A.; Tewksbury, C.; Hardman, D.; Bank, C.; Noblett, J.; Semken, S.; Kroeger, G.

    2007-12-01

    The Navajo Volcanic Field (NVF) is an area of late-Tertiary volcanism along the New Mexico-Arizona border near the Four Corners region of the American Southwest. Among the roughly 80 exhumed diatremes that comprise the NVF, Ship Rock and The Thumb are two diatremes that present an interesting problem concerning magma ascent and emplacement within the NVF. Are the diatremes remnants of classical volcanoes with underlying magma chambers, or are the diatremes formed from buds off of upward propagating dike swarms? The 2006 Keck Consortium Geophysics Project collected non-invasive gravity and magnetic data to image the subsurface of Ship Rock and The Thumb to suggest constraints concerning the formation of these diatremes within the Navajo Volcanic Field. At Ship Rock, we collected over 120 gravity points spaced 500 m apart along 10 lines. We also collected about 65,000 magnetic points that cover an area of 1,570,000 square meters surrounding Ship Rock. The gravity data reveal gravity lows several kilometers away from Ship Rock, probably as a result of thick sedimentary units close to the surface. A steep gradient of 5 mGal/km separates the gravity lows from a strong gravity high immediately to the southwest of Ship Rock. We interpret this gravity high to be uneven basement topography or a magma chamber at depth; further studies are required to determine which of the interpretations is more likely. The Ship Rock magnetic data show the prominent west and northeast dikes extend well beyond their surface outcrops while the southern dike extends only to its visible termination. The magnetic data we collected at The Thumb along ~18 km of lines reveal a linear northeast-southwest trending magnetic anomaly about 105 to 360 nT in amplitude that crosses the diatreme. We interpret the anomaly to be a dike beneath The Thumb. Models of the total field magnetic data suggest a dike at shallow depths of about 0.1 to 4.8 m and widths of about 0.25 to 1.5 m with a steep dip to the

  19. Paleomagnetism of trap intrusions, East Siberia: Implications to flood basalt emplacement and the Permo-Triassic crisis of biosphere

    Science.gov (United States)

    Konstantinov, Konstantin M.; Bazhenov, Mikhail L.; Fetisova, Anna M.; Khutorskoy, Mikhail D.

    2014-05-01

    Despite decades of concentrated studies, large igneous provinces (LIPs) are still among the most enigmatic phenomena of the Earth evolution. Among the myriad questions facing researchers, the duration of eruptive magmatic activity and its distribution through time are probably the most mysterious ones. Although the accuracy of modern dating techniques offers relatively high resolution, it is impossible to discriminate whether magmatic activity was more or less uniform or concentrated in few powerful outbursts. Consequently, many "trap-related" questions, from their origin to possible impact on the biosphere, still cannot be answered. Some of the above questions can be addressed with paleomagnetic data as have been effectively done in the case of the end-Cretaceous Deccan traps. The Siberian traps are one of the largest LIPs in the Phanerozoic and are thought, by some, to be the triggering event for the end-Permian mass extinction. We conducted a paleomagnetic study of trap intrusions along two long profiles in the eastern part of the province and found that most site-mean directions are grouped several times tighter than is common for the data on thick lava series and dyke swarms; similar over-grouping is found in other parts of the Siberian trap province too. We argue that this phenomenon is the most likely related to nearly simultaneous emplacement of trap intrusions over areas of several ten to few hundred kilometers in dimension for few millenniums or even faster. Moreover, such brief events account for all, or nearly all, magmatism in each area; how such events correlate over the entire Siberian LIP, however, remains an open question. Still, our data together with paleomagnetic results on thick lava series in Siberia strongly indicate that magmatic activity consisted of a number of brief pulses. In comparison to the other LIPs, the Siberian one is underlain by the thickest succession of carbonates, evaporites and coal-bearing clastics that are capable of

  20. Emplacement processes of tuffaceous sandstones at IODP Site C0011B, Nankai Trough, derived from modal analysis

    Science.gov (United States)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.

    2011-12-01

    massive density-graded structure, and characteristic glass composition of each sandstone bed as well as as their occurrence ~ 350 km from mainland Japan, the most likely source region, support emplacement by huge turbidity currents directly derived from major explosive volcanic eruptions, probably involving massive entrance of pyroclastic flows into the ocean. Reference: Ridolfi F, Renzulli A, Puerini M (2009) Stability and chemical equilibrium of amphibole in calc-alkaline magmas: an overview, new thermobarometric formulations and application to subduction-related volcanoes. Contrib Mineral Petrol, DOI 10.1007/s00410-009-0465-7

  1. Geological setting, emplacement mechanism and igneous evolution of the Atchiza mafic-ultramafic layered suite in north-west Mozambique

    Science.gov (United States)

    Ibraimo, Daniel Luis; Larsen, Rune B.

    2015-11-01

    system of the continental rift environment. The intrusion resulted from the emplacement of mafic magma in space created by extensional forces. Space was created through a connecting fault generated as a result of overall extensional, torsion and slab displacement in a rift system. The geometry of the body is tectonically controlled, and it agrees with the tectonic framework of the Zambezi Belt during the Rodinia breakup in the early Neoproterozoic.

  2. The effects of temperature on Schottky diode barrier height and evidence of multiple barrier

    International Nuclear Information System (INIS)

    Rabah, K.V.O.

    1994-07-01

    Experimental study of Capacitance-Voltage-Temperature (C-V-T) plots, Current-Voltage-Temperature (I-V-T) characteristics have been undertaken in order to determine the height of the Schottky barrier. The results of the barrier height obtained by the above two methods were found to differ as well as vary with temperature change. In view of this discrepancy in barrier height values, two further experiments were performed: one on activation energy (I-T) plots and the other on pulsed (I-V-T) characteristics, and the results were found to show a similar trend. The Schottky diode studied was a 30CP040. (author). 23 refs, 9 figs, 3 tabs

  3. Performing a local barrier operation

    Science.gov (United States)

    Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E

    2014-03-04

    Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value of the counter, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.

  4. Exposure, Uptake, and Barriers

    Science.gov (United States)

    Baeza-Squiban, Armelle; Lanone, Sophie

    The nanotechnologies market is booming, e.g., in the food industry (powder additives, etc.) and in medical applications (drug delivery, prosthetics, diagnostic imaging, etc.), but also in other industrial sectors, such as sports, construction, cosmetics, and so on. In this context, with an exponential increase in the number of current and future applications, it is particularly important to evaluate the problem of unintentional (i.e., non-medical) exposure to manufactured nanoparticles (so excluding nanoparticles found naturally in the environment). In this chapter, we begin by discussing the various parameters that must be taken into account in any serious assessment of exposure to man-made nanoparticles. We then list the potential routes by which nanoparticles might enter into the organism, and outline the mechanisms whereby they could get past the different biological barriers. Finally, we describe the biodistribution of nanoparticles in the organism and the way they are eliminated.

  5. Countermeasures and barriers

    International Nuclear Information System (INIS)

    Petersen, Johannes

    2005-10-01

    In 1973 Haddon proposed ten strategies for reducing and avoiding damages based on a model of potential harmful energy transfer (Haddon, 1973). The strategies apply to a large variety of unwanted phenomena. Haddon's pioneering work on countermeasures has had a major influence on later thinking about safety. Considering its impact it is remarkable that the literature offers almost no discussions related to the theoretical foundations of Haddon's countermeasure strategies. The present report addresses a number of theoretical issues related to Haddon's countermeasure strategies, which are: 1) A reformulation and formalization of Haddon's countermeasure strategies. 2) An identification and description of some of the problems associated with the term 'barrier'. 3) Suggestions for a more precise terminology based on the causal structure of countermeasures. 4) Extending the scope of countermeasures to include sign-based countermeasures. (au)

  6. Countermeasures and barriers

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Johannes [Oersted - DTU, Automation, Kgs. Lyngby (Denmark)

    2005-10-01

    In 1973 Haddon proposed ten strategies for reducing and avoiding damages based on a model of potential harmful energy transfer (Haddon, 1973). The strategies apply to a large variety of unwanted phenomena. Haddon's pioneering work on countermeasures has had a major influence on later thinking about safety. Considering its impact it is remarkable that the literature offers almost no discussions related to the theoretical foundations of Haddon's countermeasure strategies. The present report addresses a number of theoretical issues related to Haddon's countermeasure strategies, which are: 1) A reformulation and formalization of Haddon's countermeasure strategies. 2) An identification and description of some of the problems associated with the term 'barrier'. 3) Suggestions for a more precise terminology based on the causal structure of countermeasures. 4) Extending the scope of countermeasures to include sign-based countermeasures. (au)

  7. Deformation mechanisms accommodating the emplacement of an igneous sill-complex in the Irish sector of the Rockall Basin, offshore NW Ireland

    Science.gov (United States)

    Magee, Craig; Jackson, Christopher; Schofield, Nick

    2013-04-01

    Magma intrusion within the subsurface is heavily influenced by the pre-existing architecture of the upper crust and, depending on the emplacement mechanisms, may modify basin structure and fluid flow pathways. Seismic reflection data reveal that intrusive networks predominantly consist of interconnected, saucer-shaped sills that are often associated with dome-shaped 'forced' folds generated by intrusion-induced uplift. Previous studies of intrusion-related forced folds have primarily focused on isolated sills or laccoliths and have shown that the fold amplitude is less than the intrusion thickness, suggesting that additional space-making mechanisms (e.g. grain comminution, fluidization) accompanied emplacement. Furthermore, forced folding is often considered as an instantaneous process over geological time. However, fold growth and the interplay between accompanying ductile and brittle deformation styles remains poorly understood. Here, we use 3D seismic reflection data from the eastern margin of the Irish Rockall Basin, NE Atlantic, to quantitatively study eighty-two igneous intrusions (i.e. saucer-shaped sills and inclined sheets) in order to constrain the emplacement history of a Palaeocene-to-Middle Eocene sill-complex. Emplacement occurred across a Cretaceous clastic-to-marl dominated succession at palaeodepths of <5 km. Northwards-dipping, planar transgressive sheet intrusions are most abundant in the deeper portion of the sill-complex and magma flow indicators within them (i.e. steps and broken bridges) reveal that magma flowed upwards and outwards, feeding into shallow-level saucer-shaped sills at the peak of the transgressive limbs. The saucer-shaped sills are characterized by radial magma flow patterns, emanating from the inner sill, distinguished by mapping the long axes of magma lobes and fingers. These magma flow indictors also provide a proxy for intrusion style; i.e. where sills intrude the Lower Cretaceous sandstones, magma propagation was

  8. Thames barrier (flood protection barriers on the Thames)

    International Nuclear Information System (INIS)

    Ilkovic, J.

    2005-01-01

    In this paper the flood protection barriers on the Thames are presented. The flood protection system on the Thames in 1984 was commissioned. During two decades this barrier was used 54 times against to the high water and 34 times against storm-sewage. There is installed buttress type hydroelectric power plant

  9. Barriers to Maori sole mothers’ primary health care access

    Directory of Open Access Journals (Sweden)

    Lee R

    2013-12-01

    Full Text Available INTRODUCTION: International research consistently shows that sole mothers experience poorer health and suboptimal health care access. New Zealand studies on sole mothers' health report similar findings. The aim of this exploratory research was to better understand the experiences of Maori sole mothers' access to health services, particularly primary health care, for personal health needs. METHODS: This qualitative study employed a general inductive design informed by a Kaupapa Maori approach, providing guidance on appropriate cultural protocols for recruiting and engaging Maori participants. Distributing written information and snowballing techniques were used to purposively recruit seven Maori sole mothers. Data collection involved semi-structured interviews which were digitally recorded and transcribed verbatim. Data were analysed using general inductive thematic analysis to identify commonalities and patterns in participants' experiences. FINDINGS: The dominant themes that emerged captured and described participants' experiences in accessing health care. The major barrier to access reported was cost. Compounding cost, transport difficulties and location or scheduling of services were additional barriers to health service accessibility. Child-related issues also posed a barrier, including prioritising children's needs and childcare over personal health needs. CONCLUSION: The findings illuminate Maori sole mothers' experiences of accessing health care and the complex socioeconomic inequalities affecting access options and uptake of services. Further investigation of barriers to access is needed. The study has implications for addressing barriers to access at policy, funding and practice levels to improve health outcomes and equitable health care access for Maori sole mothers.

  10. Decoherence in high barrier quantum cascade structures

    Science.gov (United States)

    Freeman, Will

    2017-07-01

    High barrier AlxGa1-xAs terahertz quantum cascade structures with AlAs compositions up to 30% are studied. The influence of thermally excited leakage scattering to higher bound energy states and decoherence effects are investigated using a density matrix method where the pure dephasing time is self-consistently solved. The lattice temperature dependence of the light output in diagonal optical transition structures is calculated and shown to be consistent with experiment. Scattering from the upper lasing state to higher bound energy states is found to have minimal effects, and rather the decoherence from the calculated reduction of the pure dephasing time due to the impurity interaction is primarily responsible for the temperature dependence of a recently reported structure. This shows that the effects from an increased impurity interaction due to thinner barriers and different well dimensions can dominate over that from the increased interface roughness interaction due to higher potentials.

  11. Decreasing barriers for nurse practitioner social entrepreneurship.

    Science.gov (United States)

    Sharp, Dayle B; Monsivais, Diane

    2014-10-01

    To describe difficulties associated with the business-related aspects of practice in role transition of rural nurse practitioners (NPs), and to give practice implications. This focused ethnographic study derived data from semi-structured interviews. Participants provided information about rural NP practice ownership and barriers. The sample consisted of 24 rural NPs living throughout the United States. The majority were 51-60 years of age (45%) and females (93%) who had been in rural practice for 1 to over 20 years. NP social entrepreneurs experience difficulties related to scope of practice, business skills, and role conflict. To decrease barriers for NP clinic ownership and management, NPs need to receive education related to financing a rural practice, legal/regulatory practices, strategic planning, leadership, and clinic management. ©2014 American Association of Nurse Practitioners.

  12. Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways.

    Science.gov (United States)

    Jiang, Like; Kang, Jian

    2016-02-01

    This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5m timber barrier, and 5m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5m timber barrier tended to perform better than the 3m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Informal export barriers and poverty

    OpenAIRE

    Porto, Guido G.

    2004-01-01

    The author investigates the poverty impacts of informal export barriers like transport costs, cumbersome customs practices, costly regulations, and bribes. He models these informal barriers as export taxes that distort the efficient allocation of resources. In low-income agricultural economies, this distortion lowers wages and household agricultural income, thereby leading to higher pover...

  14. Barriers to Women in Science

    Science.gov (United States)

    Butler, Rosemary

    2013-01-01

    The Presiding Officer of the National Assembly for Wales, Rosemary Butler AM, has put the issue of barriers to women in public life at the top of the political agenda in Wales. She has held sessions with women across Wales to find out what those barriers are and how they can be tackled. On International Women's Day in February, she invited…

  15. Seismic waves and seismic barriers

    Science.gov (United States)

    Kuznetsov, S. V.

    2011-05-01

    The basic idea of seismic barrier is to protect an area occupied by a building or a group of buildings from seismic waves. Depending on nature of seismic waves that are most probable in a specific region, different kinds of seismic barriers are suggested. For example, vertical barriers resembling a wall in a soil can protect from Rayleigh and bulk waves. The FEM simulation reveals that to be effective, such a barrier should be (i) composed of layers with contrast physical properties allowing "trapping" of the wave energy inside some of the layers, and (ii) depth of the barrier should be comparable or greater than the considered seismic wave length. Another type of seismic barrier represents a relatively thin surface layer that prevents some types of surface seismic waves from propagating. The ideas for these barriers are based on one Chadwick's result concerning non-propagation condition for Ray