Science.gov

Sample records for barrier systems assessment

  1. Waste-to-energy Systems Institutional Barriers Assessment Workshop

    NASA Astrophysics Data System (ADS)

    1981-06-01

    Nontechnical institutional barriers affecting implementation of the waste to energy technology, priorization, of identifed barriers, and utilization of information and data to formulate an institutional research plarr, were identified. The following important results are recorded for commercialized and noncommercialized combustor, siting existing laws, multipurisdictional inaction, permiles and regulations, and the lack of data on environmental impacts.

  2. Status of integrated performance assessment of the waste packages and engineered barrier system

    SciTech Connect

    O`Connell, W.J.

    1990-01-01

    Performance assessment of the engineered barrier system for a nuclear waste repository combines information from relevant disciplines and predicts the net long-term performance of the EBS in unites of regulatory goals for performance. The performance assessment models are specific to the proposed Yucca Mountain, Nevada site. Early assessments are used for project planning and feedback. The EBS scenarios activity develops the scenarios and the consequent event sequences. Initial model development for single waste packages indicates that the radionuclide release rate performance is sensitive to the water flux, element solubilities, and/or the mode of water contact with the waste. The latter in turn depends on local scale hydrology and the modes of corrosion for the container material. For the release rate summed over waste packages, variations among waste packages and their near-field environments are anticipated. These variations place demands on data acquisition and modeling, as well as modulate the impact of localized changes of conditions. Sampling in uncertainty assessment is a subsequent step in examining the reliability of predictions made in the performance assessments. Advances made in sampling methods are referenced. 14 refs., 6 figs.

  3. Vehicle barrier systems

    SciTech Connect

    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.

  4. Vehicle barrier systems

    SciTech Connect

    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.

  5. Vehicle barrier systems

    SciTech Connect

    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. 2 tabs.

  6. Geophysical Assessment of the Control of a Jetty on a Barrier Beach and Estuary System

    NASA Astrophysics Data System (ADS)

    Ulrich, C.; Hubbard, S.; Delaney, C.; Seymour, D.; Blom, K.; Black, W.

    2013-12-01

    An evaluation is underway at the Goat Rock State Beach, which is located at the mouth of the Russian River near Jenner, CA. The study focuses on quantifying the influence of a man made jetty on the functioning of a barrier beach and associated implications for estuary fish habitat and flood control. Flow through the beach results from water level differences between the estuary and the ocean. When the estuary is closed or perched, one of the potential major sources of outflow from the lagoon is seepage flow through the barrier beach. The location and design of the jetty could be altering subsurface flow paths through the jetty and possibly impeding or enhancing subsurface flow where the jetty is still intact. This will result in unnatural connectivity between the ocean and the estuary leading to atypical surface water elevations and possibly salinity imbalance. Results of the assessment will enable the Sonoma County Water Agency to understand how the jetty affects formation of the barrier beach and water surface elevations within the estuary. As one aspect of the evaluation, we are using geophysical methods to monitor seepage through the jetty as well as through the beach berm. We are using multiple surface geophysical methods, including: electrical resistivity, seismic refraction, ground penetrating radar, and electromagnetic methods. In general, seismic data are being used to characterize deeper bedrock controls on beach barrier functioning such as, channeling of estuarine water beneath the barrier beach. Electrical and electromagnetic methods are being used to characterize the beach sediment layers that could contribute to preferential flow paths during tide cycles in addition to preferential flow paths created by the jetty structure. Time-lapse electrical and electromagnetic data are being used to monitor moisture changes and mixing of saline and fresh water within the beach berm. Ground penetrating radar data are being used to delineate the geometry of the

  7. Geophysical Assessment of the Control of a Jetty on a Barrier Beach and Estuary System

    NASA Astrophysics Data System (ADS)

    Ulrich, C.; Hubbard, S. S.; Peterson, J.; Blom, K.; Black, W.; Delaney, C.; Mendoza, J.

    2014-12-01

    An evaluation is underway at the Goat Rock State Park, located at the mouth of the Russian River near Jenner, CA, to quantify the influence of a man made jetty on the functioning of a barrier beach and associated implications for estuary fish habitat and flood control. Flow through the beach results from water level differences between the estuary and the ocean. When the estuary is closed or perched, one of the major sources of outflow from the lagoon is seepage flow through the barrier beach. The location and design of the jetty could be altering subsurface flow paths through the jetty and possibly impeding subsurface flow where the jetty is still intact. This will result in unnatural connectivity between the ocean and the estuary leading to atypical surface water elevations and possibly salinity imbalance. We are monitoring seepage through the jetty and beach berm with multiple surface and borehole geophysical methods, including: electrical resistivity (ERT), seismic refraction (SR), ground penetrating radar (GPR), and electromagnetic methods (EM). We use SR data to characterize deeper bedrock controls on beach barrier functioning; ERT and EM methods to characterize the beach sediment layers that could contribute to preferential flow paths during tide cycles in addition to preferential flow paths created by the jetty structure; time-lapse ERT and EM data to monitor moisture changes and mixing of saline and fresh water within the beach berm, and borehole ERT and GPR data to delineate the geometry of the (often buried) jetty. Preliminary ERT and EM results indicate two preferential flow paths through zones of missing jetty structure, while time-lapse borehole ERT data is expected to image saltwater flow impedance in zones of intact jetty structure. All data are being integrated with topography, tidal, borehole, and hydrological information and the results of the assessment will enable the Sonoma County Water Agency to develop the feasibility of alternatives to the

  8. Thermal barrier coating system

    NASA Technical Reports Server (NTRS)

    Stecura, S. (Inventor)

    1984-01-01

    A high temperature oxidation resistant, thermal barrier coating system is disclosed for a nickel cobalt, or iron base alloy substrate. An inner metal bond coating contacts the substrate, and a thermal barrier coating covers the bond coating. NiCrAlR, FeCrAlR, and CoCrAlR alloys are satisfactory as bond coating compositions where R=Y or Yb. These alloys contain, by weight, 24.9-36.7% chromium, 5.4-18.5% aluminum, and 0.05 to 1.55% yttrium or 0.05 to 0.53% ytterbium. The coatings containing ytterbium are preferred over those containing yttrium. An outer thermal barrier coating of partial stabilized zirconium oxide (zirconia) which is between 6% and 8%, by weight, of yttrium oxide (yttria) covers the bond coating. Partial stabilization provides a material with superior durability. Partially stabilized zirconia consists of mixtures of cubic, tetragonal, and monoclinic phases.

  9. Assessing the use of poplar tree systems as a landfill evapotranspiration barrier with the SHAW model.

    PubMed

    Preston, G M; McBride, R A

    2004-08-01

    The use of poplar tree systems (PTS) as evapotranspiration barriers on decommissioned landfills is gaining attention as an option for leachate management. This study involved field-testing the Simultaneous Heat and Water (SHAW) model for its ability to reliably estimate poplar transpiration, volumetric soil water content, and soil temperature at a landfill located in southern Ontario, Canada. The model was then used to estimate deep drainage and to ascertain the influence of a young PTS on the soil water balance of the landfill cover. The SHAW model tended to underestimate poplar transpiration [mean difference (MD) ranged from 0.33 to 3.55 mm on a daily total basis] and overestimate volumetric soil water content by up to 0.10 m3 m(-3). The model estimated soil temperature very well, particularly in the upper 1 m of the landfill cover (MD ranged from -0.1 to 1.6 x degrees C in this layer). The SHAW model simulations showed that deep drainage decreased appreciably with the presence of a young PTS largely through increased interception of rainfall, and that PTS have a good potential to act as effective evapotranspiration barriers in northern temperate climate zones. PMID:15462337

  10. Multilayer thermal barrier coating systems

    DOEpatents

    Vance, Steven J.; Goedjen, John G.; Sabol, Stephen M.; Sloan, Kelly M.

    2000-01-01

    The present invention generally describes multilayer thermal barrier coating systems and methods of making the multilayer thermal barrier coating systems. The thermal barrier coating systems comprise a first ceramic layer, a second ceramic layer, a thermally grown oxide layer, a metallic bond coating layer and a substrate. The thermal barrier coating systems have improved high temperature thermal and chemical stability for use in gas turbine applications.

  11. Barrier rf systems in synchrotrons

    SciTech Connect

    Chandra M. Bhat

    2004-06-28

    Recently, many interesting applications of the barrier RF system in hadron synchrotrons have been realized. A remarkable example of this is the development of longitudinal momentum mining and implementation at the Fermilab Recycler for extraction of low emittance pbars for the Tevatron shots. At Fermilab, we have barrier RF systems in four different rings. In the case of Recycler Ring, all of the rf manipulations are carried out using a barrier RF system. Here, the author reviews various uses of barrier rf systems in particle accelerators including some new schemes for producing intense proton beam and possible new applications.

  12. Thermal barrier coating system

    NASA Technical Reports Server (NTRS)

    Stecura, S. (Inventor)

    1985-01-01

    An oxide thermal barrier coating comprises ZrO3-Yb2O3 that is plasma sprayed onto a previously applied bond coating. The zirconia is partially stabilized with about 124 w/o ytterbia to insure cubic, monoclinic, and terragonal phases.

  13. Systems study on engineered barriers: barrier performance analysis

    SciTech Connect

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

    1980-09-01

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

  14. Stimulated recall methodology for assessing work system barriers and facilitators in family-centered rounds in a pediatric hospital.

    PubMed

    Carayon, Pascale; Li, Yaqiong; Kelly, Michelle M; DuBenske, Lori L; Xie, Anping; McCabe, Brenna; Orne, Jason; Cox, Elizabeth D

    2014-11-01

    Human factors and ergonomics methods are needed to redesign healthcare processes and support patient-centered care, in particular for vulnerable patients such as hospitalized children. We implemented and evaluated a stimulated recall methodology for collective confrontation in the context of family-centered rounds. Five parents and five healthcare team members reviewed video records of their bedside rounds, and were then interviewed using the stimulated recall methodology to identify work system barriers and facilitators in family-centered rounds. The evaluation of the methodology was based on a survey of the participants, and a qualitative analysis of interview data in light of the work system model of Smith and Carayon (1989, 2001). Positive survey feedback from the participants was received. The stimulated recall methodology identified barriers and facilitators in all work system elements. Participatory ergonomics methods such as the stimulated recall methodology allow a range of participants, including parents and children, to participate in healthcare process improvement.

  15. Stimulated Recall Methodology for Assessing Work System Barriers and Facilitators in Family-Centered Rounds in a Pediatric Hospital

    PubMed Central

    Carayon, Pascale; Li, Yaqiong; Kelly, Michelle M.; DuBenske, Lori L.; Xie, Anping; McCabe, Brenna; Orne, Jason; Cox, Elizabeth D.

    2014-01-01

    Human factors and ergonomics methods are needed to redesign healthcare processes and support patient-centered care, in particular for vulnerable patients such as hospitalized children. We implemented and evaluated a stimulated recall methodology for collective confrontation in the context of family-centered rounds. Five parents and five healthcare team members reviewed video records of their bedside rounds, and were then interviewed using the stimulated recall methodology to identify work system barriers and facilitators in family-centered rounds. The evaluation of the methodology was based on a survey of the participants, and a qualitative analysis of interview data in light of the work system model of Smith and Carayon (1989; 2000). Positive survey feedback from the participants was received. The stimulated recall methodology identified barriers and facilitators in all work system elements. Participatory ergonomics methods such as the stimulated recall methodology allow a range of participants, including parents and children, to participate in healthcare process improvement. PMID:24894378

  16. Engineered Barrier System: Physical and Chemical Environment

    SciTech Connect

    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.

  17. Assessment study for multi-barrier system used in radioactive borate waste isolation based on Monte Carlo simulations.

    PubMed

    Bayoumi, T A; Reda, S M; Saleh, H M

    2012-01-01

    Radioactive waste generated from the nuclear applications should be properly isolated by a suitable containment system such as, multi-barrier container. The present study aims to evaluate the isolation capacity of a new multi-barrier container made from cement and clay and including borate waste materials. These wastes were spiked by (137)Cs and (60)Co radionuclides to simulate that waste generated from the primary cooling circuit of pressurized water reactors. Leaching of both radionuclides in ground water was followed and calculated during ten years. Monte Carlo (MCNP5) simulations computed the photon flux distribution of the multi-barrier container, including radioactive borate waste of specific activity 11.22KBq/g and 4.18KBq/g for (137)Cs and (60)Co, respectively, at different periods of 0, 15.1, 30.2 and 302 years. The average total flux for 100cm radius of spherical cell was 0.192photon/cm(2) at initial time and 2.73×10(-4)photon/cm(2) after 302 years. Maximum waste activity keeping the surface radiation dose within the permissible level was calculated and found to be 56KBq/g with attenuation factors of 0.73cm(-1) and 0.6cm(-1) for cement and clay, respectively. The average total flux was 1.37×10(-3)photon/cm(2) after 302 years. Monte Carlo simulations revealed that the proposed multi-barrier container is safe enough during transportation, evacuation or rearrangement in the disposal site for more than 300 years.

  18. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    R. Jarek

    2004-11-23

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

  19. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    G.H. Nieder-Westermann

    2005-04-07

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

  20. Model assessment of protective barrier designs: Part 2

    SciTech Connect

    Fayer, M.J.

    1987-11-01

    Protective barriers are being considered for use at the Hanford Site to enhance the isolation of radioactive wastes from water, plant, and animal intrusion. This study assesses the effectiveness of protective barriers for isolation of wastes from water. In this report, barrier designs are reviewed and several barrier modeling assumptions are tested. 20 refs., 16 figs., 6 tabs.

  1. A Survey to Assess Barriers to Urban Teaching Careers

    ERIC Educational Resources Information Center

    Creasey, Gary; Mays, Jennifer; Lee, Robert; D'Santiago, Verenice

    2016-01-01

    The "Urban Teaching Barriers" survey was created to assess barriers to urban teaching careers. Pre-service teachers (N = 377) completed this instrument, along with questionnaires that assessed urban teaching intentions and urban teaching self-efficacy. Six barrier domains were identified that tapped concerns over (a) lack of resources,…

  2. Metallic seal for thermal barrier coating systems

    NASA Technical Reports Server (NTRS)

    Miller, Robert A. (Inventor)

    1990-01-01

    The invention is particularly concerned with sealing thermal barrier coating systems of the type in use and being contemplated for use in diesel and other internal combustion engines. The invention also would find application in moderately high temperature regions of gas turbine engines and any other application employing a thermal barrier coating at moderate temperatures. Ni-35Cr-6Al-1Y, Ni-35Cr-6Al-1Yb, or other metallic alloy denoted as MCrAlx is applied over a zirconia-based thermal barrier overlayer. The close-out layer is glass-bead preened to densify its surface. This seals and protects the thermal barrier coating system.

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

    SciTech Connect

    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.

  4. SUBSURFACE BARRIER VALIDATION WITH THE SEAFACE SYSTEM

    SciTech Connect

    Sandra Dalvit Dunn

    1997-11-30

    The overall objective of the effort was to develop and demonstrate an integrated methodology and field system to evaluate the integrity of in situ, impermeable barriers constructed in the vadose zone. An autonomous, remotely accessible, automatic monitoring and analysis system was designed and fabricated. It was thoroughly tested under field conditions, and was able to function as designed throughout the test period. Data inversion software was developed with enhanced capabilities over the previous prototype version, and integrated with the monitoring system for real time operation. Analytical simulations were performed to determine the inversion code's sensitivity to model parameters. Numerical simulations were performed to better understand how typical field conditions differ from the ideal model(s) which are used (or have been developed for use) in the inversion code and to further validate the flux limited forward model developed for use with the system. Results from the analytical and numerical assessment of the inversion code showed that the SEAtrace{trademark} approach could locate leaks within 0.4 to 1.2 m. Leak size determination was less accurate, but produced results within a factor of 3 to 8 for leaks in the 2.5 to 10 cm diameter range. The smallest engineered leak in the test 1.1 cm diameter, could be located but its size estimate was high by a factor of 30. Data analysis was performed automatically after each gas scan was completed, yielding results in less than thirty minutes, although the bulk of the results reported required post test data analysis to remove effects of high background concentrations. The field test of the integrated system was problematic, primarily due to unanticipated, unintentional leaks formed in the impermeable liner. The test facility constructed to proof the system was ambitious, initially having 11 engineered leaks of various dimensions that could be independently operated. While a great deal of care went into the

  5. Double barrier system for an in situ conversion process

    DOEpatents

    McKinzie, Billy John [Houston, TX; Vinegar, Harold J [Bellaire, TX; Cowan, Kenneth Michael [Sugar land, TX; Deeg, Wolfgang Friedrich Johann [Houston, TX; Wong, Sau-Wai [Rijswijk, NL

    2009-05-05

    A barrier system for a subsurface treatment area is described. The barrier system includes a first barrier formed around at least a portion of the subsurface treatment area. The first barrier is configured to inhibit fluid from exiting or entering the subsurface treatment area. A second barrier is formed around at least a portion of the first barrier. A separation space exists between the first barrier and the second barrier.

  6. ENGINEERED BARRIER SYSTEM: PHYSICAL AND CHEMICAL ENVIRONMENT

    SciTech Connect

    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 documents. The updates

  7. Assessment of blood-retinal barrier integrity.

    PubMed

    Vinores, S A

    1995-01-01

    The blood-retinal barrier consists of two components which are comprised of the retinal vascular endothelium and the retinal pigment epithelium, respectively. Its functional integrity can be recognized by tight junctions between these cells with a paucity of endocytic vesicles within them and the presence of the molecules that regulate the ionic and metabolic gradients that constitute the barrier. The barrier is compromised in several disease processes and by a variety of agents, but in most cases the location and mechanism for barrier failure is not understood. Perfusion with a variety of radiolabeled tracer molecules, vitreous fluorophotometry, or magnetic resonance imaging can be used to quantitate blood-retinal barrier leakage. Fluorescein angiography or magnetic resonance imaging can localize sites of leakage in vivo with limited resolution. Evans blue dye can be used to visualize blood-retinal barrier failure in gross pathological specimens and immuno-histochemical labeling of serum proteins such as albumin or fibrinogen can be used to localize sites of blood-retinal barrier breakdown by light microscopy. Tracers such as horseradish peroxidase, microperoxidase, or lanthanum, or the immunocytochemical demonstration of albumin can be used to reveal blood-retinal barrier breakdown at the ultrastructural level and provide insights into the mechanisms involved. This review discusses the advantages and limitations of each of these methods to aid in selection of the appropriate techniques to derive the desired information.

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

    SciTech Connect

    Flach, G. P.; Burns, H. H.; Langton, C.; Smith, F. G. III; Brown, K. G.; Kosson, D. S.; Garrabrants, A. C.; Sarkar, S.; van der Sloot, H.; Meeussen, J. C.L.; Samson, E.; Mallick, P.; Suttora, L.; Esh, D. W.; Fuhrmann, M. J.; Philip, J.

    2013-01-11

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

  9. Vapor-barrier Vacuum Isolation System

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  10. Engineered Barrier System: Physical and Chemical Environment Model

    SciTech Connect

    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.

  11. Schottky barrier MOSFET systems and fabrication thereof

    DOEpatents

    Welch, J.D.

    1997-09-02

    (MOS) device systems-utilizing Schottky barrier source and drain to channel region junctions are disclosed. Experimentally derived results which demonstrate operation of fabricated N-channel and P-channel Schottky barrier (MOSFET) devices, and of fabricated single devices with operational characteristics similar to (CMOS) and to a non-latching (SRC) are reported. Use of essentially non-rectifying Schottky barriers in (MOS) structures involving highly doped and the like and intrinsic semiconductor to allow non-rectifying interconnection of, and electrical accessing of device regions is also disclosed. Insulator effected low leakage current device geometries and fabrication procedures therefore are taught. Selective electrical interconnection of drain to drain, source to drain, or source to source, of N-channel and/or P-channel Schottky barrier (MOSFET) devices formed on P-type, N-type and Intrinsic semiconductor allows realization of Schottky Barrier (CMOS), (MOSFET) with (MOSFET) load, balanced differential (MOSFET) device systems and inverting and non-inverting single devices with operating characteristics similar to (CMOS), which devices can be utilized in modulation, as well as in voltage controlled switching and effecting a direction of rectification. 89 figs.

  12. Schottky barrier MOSFET systems and fabrication thereof

    DOEpatents

    Welch, James D.

    1997-01-01

    (MOS) device systems-utilizing Schottky barrier source and drain to channel region junctions are disclosed. Experimentally derived results which demonstrate operation of fabricated N-channel and P-channel Schottky barrier (MOSFET) devices, and of fabricated single devices with operational characteristics similar to (CMOS) and to a non-latching (SRC) are reported. Use of essentially non-rectifying Schottky barriers in (MOS) structures involving highly doped and the like and intrinsic semiconductor to allow non-rectifying interconnection of, and electrical accessing of device regions is also disclosed. Insulator effected low leakage current device geometries and fabrication procedures therefore are taught. Selective electrical interconnection of drain to drain, source to drain, or source to source, of N-channel and/or P-channel Schottky barrier (MOSFET) devices formed on P-type, N-type and Intrinsic semiconductor allows realization of Schottky Barrier (CMOS), (MOSFET) with (MOSFET) load, balanced differential (MOSFET) device systems and inverting and non-inverting single devices with operating characteristics similar to (CMOS), which devices can be utilized in modulation, as well as in voltage controled switching and effecting a direction of rectification.

  13. Final Barrier: Small System Compliance

    EPA Science Inventory

    This presentation will discuss the use of point-of-use (POU) technology for small drinking water systems. Information will be provided on the USEPA regulations that allow the use of POU for compliance and the technologies that are listed as SSCT for radium and arsenic. Listing o...

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

    SciTech Connect

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

    SciTech Connect

    Balady, M.A.

    1997-01-14

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

  16. 14 CFR 23.691 - Artificial stall barrier system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Artificial stall barrier system. 23.691... Construction Control Systems § 23.691 Artificial stall barrier system. If the function of an artificial stall... pitching motion. (d) Each system must be designed so that the artificial stall barrier can be quickly...

  17. Safety assessment of discharge chute isolation barrier preparation and installation

    SciTech Connect

    Meichle, R.H.

    1994-10-21

    This analysis examines activities associated with the installation of isolation barriers in the K Basins at the Hanford Reservation. This revision adds evaluation of barrier drops on stored fuel and basin floor, identifies fuel which will be moved and addresses criticality issues with sludge. The safety assessment is made for the activities for the preparation and installation of the discharge chute isolation barriers. The safety assessment includes a hazard assessment and comparisons of potential accidents/events to those addressed by the current safety basis documentation. No significant hazards were identified. An evaluation against the USQ evaluation questions was made and the determination made that the activities do not represent a USQ. Hazard categorization techniques were used to provide a basis for readiness review classifications.

  18. Health technology assessment in Iran: Barriers and solutions

    PubMed Central

    Mohtasham, Farideh; Yazdizadeh, Bahareh; Zali, Zahra; Majdzadeh, Reza; Nedjat, Sima

    2016-01-01

    Background: Health technology assessment (HTA) is a tool utilized for efficient dissemination of technology. For the purpose of encouraging decision-makers to utilize this tool, at first, we need to identify the obstacles in the processes of preparation, utilization, and implementation of HTAs. This study aims to define these barriers and offer solutions for effective utilization of HTA reports produced in Iran. Methods: This qualitative content analysis determines the various beneficiaries of HTA, and utilizes a semi-structured interview with the participants who are all involved in the HTA. Results: Nine out of ten people invited for the interviews accepted the researchers’ invitation. An analysis of barriers and solutions for improving the utilization of HTA reports was conducted in three levels of policy makers (policy level), specialists in healthcare (professional level), and ordinary people (public level). The barriers in the policy level include unsuitability of reports for their audience, incompatible views toward the definition and necessity of health technology assessment, lack of financial resources for report preparation, and limitations in large-scale policymaking in Ministry of Health. Barriers in the professional level include lack of knowledge on HTA among serviceproviders. Barriers in the public level consist of information asymmetry. Conclusion: There are various barriers toward accurate utilization of HTAs in Iran. Thus, a systematic approach which involves people, brings about culture, improves infrastructures, and boosts supervision on the performance is recommended. PMID:27390691

  19. CHARACTERIZATION OF A RIGID BARRIER FILTER SYSTEM

    SciTech Connect

    Chiang, Ta-Kuan

    2001-11-06

    A mathematical model is formulated to describe the dynamics of a rigid barrier filter system. Complete with filtration, regeneration and particle re-deposition, this model provides sizing information for new filter systems and diagnostic information for operating filter systems. To turn this model into a practical and smart filter system predictive model, monitoring devices for variables such as real-time particle concentration and size distribution are currently under laboratory development. The program goal is to introduce a smart filter system to supervise its operation and to assure its system reliability. Primarily, a smart filter system will update operating information, sound up malfunction alarms, and provide self-activated measures such as adjusting the cleaning frequency, intensity and back-pulse duration.

  20. ENGINEERED BARRIER SYSTEM FEATURES, EVENTS AND PROCESSES

    SciTech Connect

    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 (YMP) administrative procedures as they

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

    SciTech Connect

    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).

  2. Article Including Environmental Barrier Coating System

    NASA Technical Reports Server (NTRS)

    Lee, Kang N. (Inventor)

    2015-01-01

    An enhanced environmental barrier coating for a silicon containing substrate. The enhanced barrier coating may include a bond coat doped with at least one of an alkali metal oxide and an alkali earth metal oxide. The enhanced barrier coating may include a composite mullite bond coat including BSAS and another distinct second phase oxide applied over said surface.

  3. Barriers to household investment in residential energy conservation: preliminary assessment

    SciTech Connect

    Hoffman, W.L.

    1982-12-01

    A general assessment of the range of barriers which impede household investments in weatherization and other energy efficiency improvements for their homes is provided. The relationship of similar factors to households' interest in receiving a free energy audits examined. Rates of return that underly household investments in major conservation improvements are assessed. A special analysis of household knowledge of economically attractive investments is provided that compares high payback improvements specified by the energy audit with the list of needed or desirable conservation improvements identified by respondents. (LEW)

  4. Radionuclide transport through engineered barrier system alteration products

    SciTech Connect

    Viani, B.E.; Torretto, P.C.; Matzen, S.L.

    1997-12-01

    The primary rationale for studying the transport behavior of radionuclides through the Engineered Barrier system / Near Field Environment (EBS/NFE) is to ascertain whether the material properties of the introduced and altered host rock can significantly affect the transport of radionuclides from the waste container to the far field. The intent of this report is to present data and modeling results that can be used to assess the importance of canister corrosion products and cementitious materials to transport of radionuclides to the far field.

  5. Applications of barrier bucket RF systems at Fermilab

    SciTech Connect

    Bhat, C.M.; /Fermilab

    2006-03-01

    In recent years, the barrier rf systems have become important tools in a variety of beam manipulation applications at synchrotrons. Four out of six proton synchrotrons at Fermilab are equipped with broad-band barrier rf systems. All of the beam manipulations pertaining to the longitudinal phase space in the Fermilab Recycler (synchrotron used for antiproton storage) are carried out using a barrier system. Recently, a number of new applications of barrier rf systems have been developed- the longitudinal momentum mining, longitudinal phase-space coating, antiproton stacking, fast bunch compression and more. Some of these techniques have been critical for the recent spectacular success of the collider performance at the Fermilab Tevatron. Barrier bunch coalescing to produce bright proton bunches has a high potential to increase proton antiproton luminosity significantly. In this paper, I will describe some of these techniques in detail. Finally, I make a few general remarks on issues related to barrier systems.

  6. Thermal barrier coating for alloy systems

    DOEpatents

    Seals, Roland D.; White, Rickey L.; Dinwiddie, Ralph B.

    2000-01-01

    An alloy substrate is protected by a thermal barrier coating formed from a layer of metallic bond coat and a top coat formed from generally hollow ceramic particles dispersed in a matrix bonded to the bond coat.

  7. Volumetric analysis of a New England barrier system using ground-penetrating-radar and coring techniques

    USGS Publications Warehouse

    Van Heteren, S.; FitzGerald, D.M.; Barber, D.C.; Kelley, J.T.; Belknap, D.F.

    1996-01-01

    Ground-penetrating-radar (GPR) profiles calibrated with core data allow accurate assessments of coastal barrier volumes. We applied this procedure successfully to the barrier system along Saco Bay, Maine (USA), as part of a sediment-budget study that focused on present-day sand volumes in various coastal, shoreface, and inner-shelf lith-osomes, and on sand fluxes that have affected the volume or distribution of sand in these sediment bodies through time. On GPR profiles, the components of the barrier lithosome are readily differentiated from other facies, except where the radar signal is attenuated by brackish or salty groundwater. Significant differences between dielectric properties of the barrier lithosome and other units commonly result in strong boundary reflectors. The mostly sandy barrier sediments allow deep penetration of GPR waves, in contrast to finer-grained strata and till-covered bedrock. Within the Saco Bay barrier system, 22 ??3 x 106 m3 of sediment are unevenly distributed. Two-thirds of the total barrier volume is contained within the northern and southern ends of the study area, in the Pine Point spit and the Ferry Beach/Goosefare complex, respectively. The central area around Old Orchard Beach is locally covered by only a thin veneer of barrier sand, averaging <3 m, that unconformably overlies shallow pre-Holocene facies. The prominence of barrier-spit facies and the distribution pattern of back-barrier sediments indicate that a high degree of segmentation, governed by antecedent topography, has affected the development of the Saco Bay barrier system. The present-day configuration of the barrier and back-barrier region along Saco Bay, however, conceals much of its early compartmentalized character.

  8. Hybrid life cycle assessment comparison of colloidal silica and cement grouted soil barrier remediation technologies.

    PubMed

    Gallagher, Patricia M; Spatari, Sabrina; Cucura, Jeffrey

    2013-04-15

    Site remediation involves balancing numerous costs and benefits but often neglects the environmental impacts over the entire project life cycle. Life cycle assessment (LCA) offers a framework for inclusion of global environmental "systems-level" decision metrics in combination with technological and cost analysis. We compare colloidal silica (CS) and cement grouted soil barrier remediation technologies for soils affected by low level radionuclides at a U.S. Superfund site using hybrid LCA methods. CS is a new, high performance grouting material installed using permeation grouting techniques. Cement, a more traditional grouting material, is typically installed using jet grouting techniques. Life cycle impacts were evaluated using the US EPA TRACI 2 model. Results show the highest life cycle environmental impacts for the CS barrier occur during materials production and transportation to the site. In general, the life cycle impacts for the cement barrier were dominated by materials production; however, in the extreme scenario the life cycle impacts were dominated by truck transportation of spoils to a distant, off-site radioactive waste facility. It is only in the extreme scenario tested in which soils are transported by truck (Option 2) that spoils waste transport dominates LCIA results. Life cycle environmental impacts for both grout barriers were most sensitive to resource input requirements for manufacturing volumes and transportation. Uncertainty associated with the efficacy of new technology such as CS over its required design life indicates that barrier replacement could increase its life cycle environmental impact above that of the cement barrier.

  9. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    SciTech Connect

    Hampikian, J.M.; Carter, W.B.

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  10. New Trends in Quantitative Assessment of the Corneal Barrier Function

    PubMed Central

    Guimerà, Anton; Illa, Xavi; Traver, Estefania; Herrero, Carmen; Maldonado, Miguel J.; Villa, Rosa

    2014-01-01

    The cornea is a very particular tissue due to its transparency and its barrier function as it has to resist against the daily insults of the external environment. In addition, maintenance of this barrier function is of crucial importance to ensure a correct corneal homeostasis. Here, the corneal epithelial permeability has been assessed in vivo by means of non-invasive tetrapolar impedance measurements, taking advantage of the huge impact of the ion fluxes in the passive electrical properties of living tissues. This has been possible by using a flexible sensor based in SU-8 photoresist. In this work, a further analysis focused on the validation of the presented sensor is performed by monitoring the healing process of corneas that were previously wounded. The obtained impedance measurements have been compared with the damaged area observed in corneal fluorescein staining images. The successful results confirm the feasibility of this novel method, as it represents a more sensitive in vivo and non-invasive test to assess low alterations of the epithelial permeability. Then, it could be used as an excellent complement to the fluorescein staining image evaluation. PMID:24841249

  11. Pressurized security barrier and alarm system

    DOEpatents

    Carver, D.W.

    1995-04-11

    A security barrier for placement across a passageway is made up of interconnected pressurized tubing made up in a grid pattern with openings too small to allow passage. The tubing is connected to a pressure switch, located away from the barrier site, which activates an alarm upon occurrence of a pressure drop. A reinforcing bar is located inside and along the length of the tubing so as to cause the tubing to rupture and set off the alarm upon an intruder`s making an attempt to crimp and seal off a portion of the tubing by application of a hydraulic tool. Radial and rectangular grid patterns are disclosed. 7 figures.

  12. Pressurized security barrier and alarm system

    DOEpatents

    Carver, Don W.

    1995-01-01

    A security barrier for placement across a passageway is made up of interconnected pressurized tubing made up in a grid pattern with openings too small to allow passage. The tubing is connected to a pressure switch, located away from the barrier site, which activates an alarm upon occurrence of a pressure drop. A reinforcing bar is located inside and along the length of the tubing so as to cause the tubing to rupture and set off the alarm upon an intruder's making an attempt to crimp and seal off a portion of the tubing by application of a hydraulic tool. Radial and rectangular grid patterns are disclosed.

  13. Advance care planning: identifying system-specific barriers and facilitators

    PubMed Central

    Hagen, N.A.; Howlett, J.; Sharma, N.C.; Biondo, P.; Holroyd-Leduc, J.; Fassbender, K.; Simon, J.

    2015-01-01

    Background Advance care planning (acp) is an important process in health care today. How to prospectively identify potential local barriers and facilitators to uptake of acp across a complex, multi-sector, publicly funded health care system and how to develop specific mitigating strategies have not been well characterized. Methods We surveyed a convenience sample of clinical and administrative health care opinion leaders across the province of Alberta to characterize system-specific barriers and facilitators to uptake of acp. The survey was based on published literature about the barriers to and facilitators of acp and on the Michie Theoretical Domains Framework. Results Of 88 surveys, 51 (58%) were returned. The survey identified system-specific barriers that could challenge uptake of acp. The factors were categorized into four main domains. Three examples of individual system-specific barriers were “insufficient public engagement and misunderstanding,” “conflict among different provincial health service initiatives,” and “lack of infrastructure.” Local system-specific barriers and facilitators were subsequently explored through a semi-structured informal discussion group involving key informants. The group identified approaches to mitigate specific barriers. Conclusions Uptake of acp is a priority for many health care systems, but bringing about change in multi-sector health care systems is complex. Identifying system-specific barriers and facilitators to the uptake of innovation are important elements of successful knowledge translation. We developed and successfully used a simple and inexpensive process to identify local system-specific barriers and enablers to uptake of acp, and to identify specific mitigating strategies. PMID:26300673

  14. Thermal barrier coating system with intermetallic overlay bond coat

    SciTech Connect

    Duderstadt, E.C.; Nagaraj, B A.

    1993-08-24

    A superalloy article is described having a thermal barrier coating system thereon, comprising: a substrate made of a material selected from the group consisting of a nickel-based superalloy and a cobalt-based superalloy; and a thermal barrier coating system on the substrate, the thermal barrier coating system including an intermetallic bond coat overlying the substrate, the bond coat being selected from the group consisting of a nickel aluminide and a platinum aluminide intermetallic compound, a thermally grown aluminum oxide layer overlying the intermetallic bond coat, and a ceramic topcoat overlying the aluminum oxide layer.

  15. Reliability assessment on interfacial failure of thermal barrier coatings

    NASA Astrophysics Data System (ADS)

    Guo, Jin-Wei; Yang, Li; Zhou, Yi-Chun; He, Li-Min; Zhu, Wang; Cai, Can-Ying; Lu, Chun-Sheng

    2016-08-01

    Thermal barrier coatings (TBCs) usually exhibit an uncertain lifetime owing to their scattering mechanical properties and severe service conditions. To consider these uncertainties, a reliability assessment method is proposed based on failure probability analysis. First, a limit state equation is established to demarcate the boundary between failure and safe regions, and then the failure probability is calculated by the integration of a probability density function in the failure area according to the first- or second-order moment. It is shown that the parameters related to interfacial failure follow a Weibull distribution in two types of TBC. The interfacial failure of TBCs is significantly affected by the thermal mismatch of material properties and the temperature drop in service.

  16. 14 CFR 23.691 - Artificial stall barrier system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Construction Control Systems § 23.691 Artificial stall barrier system. If the function of an artificial stall... (emergency) control that meets the requirements of § 23.1329(b). (e) A preflight check of the complete system... flight characteristics if the system was not provided, and the hazard that may result from...

  17. 14 CFR 23.691 - Artificial stall barrier system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Construction Control Systems § 23.691 Artificial stall barrier system. If the function of an artificial stall... (emergency) control that meets the requirements of § 23.1329(b). (e) A preflight check of the complete system... flight characteristics if the system was not provided, and the hazard that may result from...

  18. Assessment of uncertainty in Great Barrier Reef catchment models.

    PubMed

    Herr, A; Kuhnert, P M

    2007-01-01

    This paper addresses uncertainty in socio-economic and sediment-nutrient models that are being developed for the assessment of change in the Great Barrier Reef (GBR) area. The catchments draining into the GBR lagoon are sources of pollutants. The Reef Water Quality Management Plan of the Queensland Government identified sediments and nutrients transported to the GBR lagoon as the major long-term threats to the reef and inshore ecosystems and the wellbeing of the human communities. The plan clearly indicates that changes in land management are required by 2013 to reduce pollutant inputs and, at the same time, maintain or enhance the benefits from using the inland waters. Science that provides decision tools for natural resource management and improves socio-economic and biophysical understanding is required to enable managers to make better decisions. A major research activity (the Water for a Healthy Country Flagship) aims to address social, economic and biophysical outcomes of land management change in the GBR. It contains research activities that provide information for integrated model development. Currently, however, these models lack the ability to estimate the uncertainty associated with prediction. This project aims to provide statistical methods for assessing uncertainty in models of sediment transportation to the GBR. Furthermore, it provides a link between the models and the decision-making process that allows assessment of uncertainty, a step pertinent to the risk analysis of policy options. This paper describes current and ongoing approaches for assessing uncertainty using a sediment modelling example and provides a way forward for the integration of applied socio-economic and biophysical models used in the decision-making process. PMID:17711014

  19. Combustion chemical vapor deposited coatings for thermal barrier coating systems

    SciTech Connect

    Hampikian, J.M.; Carter, W.B.

    1995-12-31

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings. In this report, the evaluation of alumina and ceria coatings on a nickel-chromium alloy is described.

  20. The role of plants on isolation barrier systems

    SciTech Connect

    Link, S.O.; Downs, J.L.; Waugh, W.J.

    1994-11-01

    Surface barriers are used to isolate buried wastes from the environment. Most have been built for short-term isolation. The need to isolate radioactive wastes from the environment requires that the functional integrity of a barrier be maintained for thousands of years. Barrier function strongly depends on vegetation. Plants reduce wind and water erosion and minimize drainage, but may transport contaminants if roots extend into buried wastes. Our review of the function of plants on surface barriers focuses on the role of plants across mesic to arid environments and gives special consideration to studies done at Hanford. The Hanford Barrier Development Program was created to design and test an earthen cover system to inhibit water infiltration, plant and animal intrusion, and wind and water erosion, while isolating buried wastes for at least 1000 years. Studies at the Hanford have shown that plants will significantly interact with the barrier. Plants transpire soil water back into the atmosphere. Deep-rooted perennials best recycle water; soil water may drain through the root zone of shallow-rooted annuals. Lysimeter studies indicate that a surface layer of fine soil with deep-rooted plants precludes drainage even with three times normal precipitation. The presence of vegetation greatly reduces water and wind erosion, but deep-rooted plants pose a threat of biointrusion and contaminant transport. The Hanford barrier includes a buried rock layer and asphalt layer to prevent biointrusion.

  1. Thermal model of attic systems with radiant barriers

    SciTech Connect

    Wilkes, K.E.

    1991-07-01

    This report summarizes the first phase of a project to model the thermal performance of radiant barriers. The objective of this phase of the project was to develop a refined model for the thermal performance of residential house attics, with and without radiant barriers, and to verify the model by comparing its predictions against selected existing experimental thermal performance data. Models for the thermal performance of attics with and without radiant barriers have been developed and implemented on an IBM PC/AT computer. The validity of the models has been tested by comparing their predictions with ceiling heat fluxes measured in a number of laboratory and field experiments on attics with and without radiant barriers. Cumulative heat flows predicted by the models were usually within about 5 to 10 percent of measured values. In future phases of the project, the models for attic/radiant barrier performance will be coupled with a whole-house model and further comparisons with experimental data will be made. Following this, the models will be utilized to provide an initial assessment of the energy savings potential of radiant barriers in various configurations and under various climatic conditions. 38 refs., 14 figs., 22 tabs.

  2. ENGINEERED BARRIER SYSTEM FEATURES, EVENTS, AND PROCESSES

    SciTech Connect

    na

    2005-05-30

    This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1 - 1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed descriptions of the model input parameters, their development and the relationship between the parameters and specific features, events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2005 [DIRS 172827]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis'' (Figure 1 - 1). The objective of this analysis was to develop the BDCFs for the

  3. Barriers to the Assessment of Unmet Need in Planning HIV/AIDS Prevention Programs.

    ERIC Educational Resources Information Center

    Valdiserri, Ronald O.; West, Gary R.

    1994-01-01

    Major barriers to conducting needs assessment for AIDS prevention are resource deficits, technical deficits, environmental complexity, and apprehension about expectations. Comprehensive, methodologically sound assessments conducted collaboratively by consumers and providers of prevention services are essential. (SK)

  4. Feasibility Assessment of Thermal Barrier Seals for Extreme Transient Temperatures

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.

    1998-01-01

    The assembly joints of modem solid rocket motor cases are generally sealed using conventional O-ring type seals. The 5500+ F combustion gases produced by rocket motors are kept a safe distance away from the seals by thick layers of phenolic insulation. Special compounds are used to fill insulation gaps leading up to the seals to prevent a direct flowpath to them. Design criteria require that the seals should not experience torching or charring during operation, or their sealing ability would be compromised. On limited occasions, NASA has observed charring of the primary O-rings of the Space Shuttle solid rocket nozzle assembly joints due to parasitic leakage paths opening up in the gap-fill compounds during rocket operation. NASA is investigating different approaches for preventing torching or charring of the primary O-rings. One approach is to implement a braided rope seal upstream of the primary O-ring to serve as a thermal barrier that prevents the hot gases from impinging on the O-ring seals. This paper presents flow, resiliency, and thermal resistance for several types of NASA rope seals braided out of carbon fibers. Burn tests were performed to determine the time to burn through each of the seals when exposed to the flame of an oxyacetylene torch (5500 F), representative of the 5500 F solid rocket motor combustion temperatures. Rope seals braided out of carbon fibers endured the flame for over six minutes, three times longer than solid rocket motor burn time. Room and high temperature flow tests are presented for the carbon seals for different amounts of linear compression. Room temperature compression tests were performed to assess seal resiliency and unit preloads as a function of compression. The thermal barrier seal was tested in a subscale "char" motor test in which the seal sealed an intentional defect in the gap insulation. Temperature measurements indicated that the seal blocked 2500 F combustion gases on the upstream side with very little temperature

  5. Prioritizing barriers to successful implementation of hospital information systems.

    PubMed

    Ahmadian, Leila; Khajouei, Reza; Nejad, Simin Salehi; Ebrahimzadeh, Maryam; Nikkar, Somayeh Ezhari

    2014-12-01

    Hospital information systems (HIS) are often implemented to enhance the quality of care, as well as to improve the efficiency and safety of health care services. However, there are various barriers for their successful implementation. The aim of this paper is to prioritize these barriers. This research is a cross sectional analytic-descriptive study. The study populations were hospital managers, IT department administrators, and clinical supervisors at the academic and non-academic hospitals of two cities in Iran. The data was collected by a questionnaire that its content validity was confirmed by three specialists. Its reliability was confirmed using Cronbach's alpha (α = 0.78). Questionnaire contained five dimensions and 39 implementation barriers. The collected data was analyzed by descriptive and analytical statistics using the Kendall Rank Correlation Coefficient and Chi2 tests. The findings of the study revealed that lack of powerful information networks, error in data entry, technical problems related to system design, lack of organizational training, lack of users' knowledge about system and working with it, and negative attitudes of providers and patients toward systems are the most important barriers of HIS implementation. Prioritizing of these barriers helps policy makers to decide what to do when planning for HIS utilization.

  6. Microstructural Evolution and interfacial motion in systems with diffusion barriers

    SciTech Connect

    Perry H. Leo

    2009-03-05

    This research program was designed to model and simulate phase transformations in systems containing diffusion barriers. The modeling work included mass flow, phase formation, and microstructural evolution in interdiffusing systems. Simulation work was done by developing Cahn-Hilliard and phase field equations governing both the temporal and spatial evolution of the composition and deformation fields and other important phase variables.

  7. 14 CFR 23.691 - Artificial stall barrier system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.691 Artificial stall barrier system. If the function of an artificial stall... downward pitching control will be provided must be established. (b) Considering the plus and minus...

  8. Feasibility Assessment of Thermal Barriers for RSRM Nozzle Joint Locations

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M.; Dunlap, Patrick H., Jr.

    1999-01-01

    Solid rockets, including the Space Shuttle solid rocket motor, are generally manufactured in large segments which are then shipped to their final destination where they are assembled. These large segments are sealed with a system of primary and secondary 0-rings to contain combustion gases inside the rocket which are at pressures of up to 900 psi and temperatures of up to 5500 F. The seals are protected from hot combustion gases by thick layers of phenolic insulation and by joint-filling compounds between these layers. Recently, though, routine inspections of nozzle-to-case joints in the Shuttle solid rocket motors during disassembly revealed erosion of the primary O-rings. Jets of hot gas leaked through gaps in the joint-filling compound between the layers of insulation and impinged on the O-rings. This is not supposed to take place, so NASA and Thiokol, the manufacturer of the rockets, initiated an investigation and found that design improvements could be made in this joint. One such improvement would involve using NASA Lewis braided thermal barriers as another level of protection for the O-ring seals against the hot combustion gases.

  9. Assessment of barriers to establish OSH: a country report

    PubMed Central

    ARASTOO, Hadi; HAKIMOVICH, Azimov Pulod; ESFANDIARPOUR, Soraya

    2015-01-01

    In addition to its merits, industrial growth is associated with many issues and problems, including occupational injuries and diseases. The adverse effects of industrialization are function of economic, social, cultural, political and geographical condition of a country, and therefore it varies widely between different countries, especially, developed and developing countries. Establishment of occupational safety and health (OSH) is one of the important solutions to predict, prevent, reduce and harness of the related harms. Despite many relevant protocols and guidelines for establishment of OSH and decades of efforts, still, there are debates and lack of success on different approaches towards implementation of OSH, especially in developing countries. Iran has experienced industrialized growth and has gained some advancement in establishment of OSH in the region. The purpose of this study was to reach to a consensus among Iranian experts about barriers to establish OSH in developing countries, using Delphi technique. 48 experts participated in this study. Two rounds of Delphi were conducted and main barriers were identified, then the identified barriers were prioritized and weighted by the experts. Among all barriers, 17 barriers which were reported by 15 experts or more were selected and categorized as structural, managerial and implementation barriers. PMID:25914069

  10. Low temperature monitoring system for subsurface barriers

    SciTech Connect

    Vinegar, Harold J.; McKinzie, II. Billy John

    2009-08-18

    A system for monitoring temperature of a subsurface low temperature zone is described. The system includes a plurality of freeze wells configured to form the low temperature zone, one or more lasers, and a fiber optic cable coupled to at least one laser. A portion of the fiber optic cable is positioned in at least one freeze well. At least one laser is configured to transmit light pulses into a first end of the fiber optic cable. An analyzer is coupled to the fiber optic cable. The analyzer is configured to receive return signals from the light pulses.

  11. Assessment of the water quality and ecosystem health of the Great Barrier Reef (Australia): conceptual models.

    PubMed

    Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

    2007-12-01

    Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments' Reef Water Quality Protection Plan.

  12. Assessment of the Water Quality and Ecosystem Health of the Great Barrier Reef (Australia): Conceptual Models

    NASA Astrophysics Data System (ADS)

    Haynes, David; Brodie, Jon; Waterhouse, Jane; Bainbridge, Zoe; Bass, Deb; Hart, Barry

    2007-12-01

    Run-off containing increased concentrations of sediment, nutrients, and pesticides from land-based anthropogenic activities is a significant influence on water quality and the ecologic conditions of nearshore areas of the Great Barrier Reef World Heritage Area, Australia. The potential and actual impacts of increased pollutant concentrations range from bioaccumulation of contaminants and decreased photosynthetic capacity to major shifts in community structure and health of mangrove, coral reef, and seagrass ecosystems. A detailed conceptual model underpins and illustrates the links between the main anthropogenic pressures or threats (dry-land cattle grazing and intensive sugar cane cropping) and the production of key contaminants or stressors of Great Barrier Reef water quality. The conceptual model also includes longer-term threats to Great Barrier Reef water quality and ecosystem health, such as global climate change, that will potentially confound direct model interrelationships. The model recognises that system-specific attributes, such as monsoonal wind direction, rainfall intensity, and flood plume residence times, will act as system filters to modify the effects of any water-quality system stressor. The model also summarises key ecosystem responses in ecosystem health that can be monitored through indicators at catchment, riverine, and marine scales. Selected indicators include riverine and marine water quality, inshore coral reef and seagrass status, and biota pollutant burdens. These indicators have been adopted as components of a long-term monitoring program to enable assessment of the effectiveness of change in catchment-management practices in improving Great Barrier Reef (and adjacent catchment) water quality under the Queensland and Australian Governments’ Reef Water Quality Protection Plan.

  13. Distributed road assessment system

    DOEpatents

    Beer, N. Reginald; Paglieroni, David W

    2014-03-25

    A system that detects damage on or below the surface of a paved structure or pavement is provided. A distributed road assessment system includes road assessment pods and a road assessment server. Each road assessment pod includes a ground-penetrating radar antenna array and a detection system that detects road damage from the return signals as the vehicle on which the pod is mounted travels down a road. Each road assessment pod transmits to the road assessment server occurrence information describing each occurrence of road damage that is newly detected on a current scan of a road. The road assessment server maintains a road damage database of occurrence information describing the previously detected occurrences of road damage. After the road assessment server receives occurrence information for newly detected occurrences of road damage for a portion of a road, the road assessment server determines which newly detected occurrences correspond to which previously detected occurrences of road damage.

  14. Field testing of asphalt-emulsion radon-barrier system

    SciTech Connect

    Hartley, J.N.; Freeman, H.D.; Baker, E.G.; Elmore, M.R.; Nelson, D.A.; Voss, C.F.; Koehmstedt, P.L.

    1981-09-01

    Three years of laboratory and field testing have demonstrated that asphalt emulsion seals are effective radon diffusion barriers. Both laboratory and field tests in 1979, 1980 and 1981 have shown that an asphalt emulsion seal can reduce radon fluxes by greater than 99.9%. The effective diffusion coefficient for the various asphalt emulsion admix seals averages about 10/sup -6/ cm/sup 2//s. The 1981 joint field test is a culmination of all the technology developed to date for asphalt emulsion radon barrier systems. Preliminary results of this field test and the results of the 1980 field test are presented. 18 figures, 6 tables.

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

    SciTech Connect

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

    2008-09-29

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

  16. Ruthenium-containing bond coats for thermal barrier coating systems

    NASA Astrophysics Data System (ADS)

    Tryon, B.; Cao, F.; Murphy, K. S.; Levi, C. G.; Pollock, T. M.

    2006-01-01

    Bond coats for zirconia-based thermal barrier coating systems applied to nickel-based superalloys are typically composed of the B2 NiAl phase. Since RuAl has the same B2 crystal structure but a melting point 400°C higher than NiAl, ruthenium-modified aluminide bond coats could provide improved system temperature capability. Creep experiments on ternary Al-Ni-Ru alloys demonstrate greatly improved creep properties with increasing ruthenium content. Processing paths for ruthenium-modified NiAl-based bond coatings have been established within the bounds of commercially available coating systems. The oxidation resistance of ruthenium-modified bond coats during thermal cycling has been examined, and potential thermal barrier coating system implications are discussed.

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

    SciTech Connect

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

    2011-01-01

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

  18. Assessment of Barriers to Changing Practice as CME Outcomes

    ERIC Educational Resources Information Center

    Price, David W.; Miller, Elaine K.; Rahm, Alanna Kulchak; Brace, Nancy E.; Larson, R. Sam

    2010-01-01

    Introduction: Continuing medical education (CME) is meant to drive and support improvements in practice. To achieve this goal, CME activities must move beyond simply purveying knowledge, instead helping attendees to contextualize information and to develop strategies for implementing new learning. CME attendees face different barriers to…

  19. Qualitative risk assessment of subsurface barriers in applications supporting retrieval of SST waste

    SciTech Connect

    Treat, R.L.

    1994-04-01

    This report provides a brief, qualitative assessment of risks associated with the potential use of impermeable surface barriers installed around and beneath Hanford Site single-shell tanks (SSTs) to support the retrieval of wastes from those tanks. These risks are compared to qualitative assessment of costs and risks associated with a case in which barriers are not used. A quantitative assessment of costs and risks associated with these two cases will be prepared and documented in a companion report. The companion report will compare quantitatively the costs and risks of several retrieval options with varying parameters, such as effectiveness of retrieval, effectiveness of subsurface barriers, and the use of surface barriers. For ease of comparison of qualitative risks, a case in which impermeable subsurface barriers are used in conjunction with another technology to remove tank waste is referred, to in this report as the Barrier Case. A case in which waste removal technologies are used without employing a subsurface barrier is referred to as the No Barrier Case. The technologies associated with each case are described in the following sections.

  20. Analysis of developed transition road safety barrier systems.

    PubMed

    Soltani, Mehrtash; Moghaddam, Taher Baghaee; Karim, Mohamed Rehan; Sulong, N H Ramli

    2013-10-01

    Road safety barriers protect vehicles from roadside hazards by redirecting errant vehicles in a safe manner as well as providing high levels of safety during and after impact. This paper focused on transition safety barrier systems which were located at the point of attachment between a bridge and roadside barriers. The aim of this study was to provide an overview of the behavior of transition systems located at upstream bridge rail with different designs and performance levels. Design factors such as occupant risk and vehicle trajectory for different systems were collected and compared. To achieve this aim a comprehensive database was developed using previous studies. The comparison showed that Test 3-21, which is conducted by impacting a pickup truck with speed of 100 km/h and angle of 25° to transition system, was the most severe test. Occupant impact velocity and ridedown acceleration for heavy vehicles were lower than the amounts for passenger cars and pickup trucks, and in most cases higher occupant lateral impact ridedown acceleration was observed on vehicles subjected to higher levels of damage. The best transition system was selected to give optimum performance which reduced occupant risk factors using the similar crashes in accordance with Test 3-21. PMID:23820073

  1. Emergent Behavior of Coupled Barrier Island - Resort Systems

    NASA Astrophysics Data System (ADS)

    McNamara, D. E.; Werner, B. T.

    2004-12-01

    Barrier islands are attractive sites for resorts. Natural barrier islands experience beach erosion and island overwash during storms, beach accretion and dune building during inter-storm periods, and migration up the continental shelf as sea level rises. Beach replenishment, artificial dune building, seawalls, jetties and groins have been somewhat effective in protecting resorts against erosion and overwash during storms, but it is unknown how the coupled system will respond to long-term sea level rise. We investigate coupled barrier island - resort systems using an agent-based model with three components: natural barrier islands divided into a series of alongshore cells; resorts controlled by markets for tourism and hotel purchases; and coupling via storm damage to resorts and resort protection by government agents. Modeled barrier islands change by beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms. In the resort hotel market, developer agents build hotels and hotel owning agents purchase them using predictions of future revenue and property appreciation, with the goal of maximizing discounted utility. In the tourism market, hotel owning agents set room rental prices to maximize profit and tourist agents choose vacation destinations maximizing a utility based on beach width, price and word-of-mouth. Government agents build seawalls, groins and jetties, and widen the beach and build up dunes by adding sand to protect resorts from storms, enhance beach quality, and maximize resort revenue. Results indicate that barrier islands and resorts evolve in a coupled manner to resort size saturation, with resorts protected against small-to-intermediate-scale storms under fairly stable sea level. Under extended, rapidly rising sea level, protection measures enhance the effect of large storms, leading to emergent behavior in the form of limit cycles or barrier submergence

  2. TEER measurement techniques for in vitro barrier model systems

    PubMed Central

    Srinivasan, Balaji; Kolli, Aditya Reddy; Esch, Mandy Brigitte; Abaci, Hasan Erbil; Shuler, Michael L.; Hickman, James J.

    2015-01-01

    Transepithelial/transendothelial electrical resistance (TEER) is a widely accepted quantitative technique to measure the integrity of tight junction dynamics in cell culture models of endothelial and epithelial monolayers. TEER values are strong indicators of the integrity of the cellular barriers before they are evaluated for transport of drugs or chemicals. TEER measurements can be performed in real-time without cell damage and generally are based on measuring ohmic resistance or measuring impedance across a wide spectrum of frequencies. TEER measurements for various cell types have been reported with commercially available measurement systems and also with custom built microfluidic implementations. Some of the barrier models that have been widely characterized utilizing TEER include the blood-brain barrier (BBB), gastrointestinal (GI) tract, and pulmonary models. Variations in TEER value can arise due to factors such as temperature, medium formulation and passage number of cells. The aim of this paper is to review the different TEER measurement techniques and analyze their strengths and weaknesses, the significance of TEER in drug toxicity studies, examine the various in vitro models and microfluidic organs-on-chips implementations utilizing TEER measurements in some widely studied barrier models (BBB, GI tract and pulmonary), and discuss the various factors that can affect TEER measurements. PMID:25586998

  3. Barriers to success: How baculoviruses establish efficient systemic infections

    PubMed Central

    Passarelli, A. Lorena

    2011-01-01

    The mechanisms used by baculoviruses to exit the midgut and cause systemic infection of their insect hosts have been debated for decades. After being ingested, baculoviruses reach the midgut, where several host barriers need to be overcome in order to establish successful infection. One of these barriers is the basal lamina, a presumably virus-impermeable extracellular layer secreted by the epithelial cells lining the midgut and trachea. This review discusses new evidence that demonstrates how these viruses breach the basal lamina and establish efficient systemic infections. The biochemical mechanisms involved in dismantling basal lamina during baculovirus infection may also provide new insights into the process of basal lamina remodeling in invertebrate and vertebrate animals. PMID:21300392

  4. Computational Design and Experimental Validation of New Thermal Barrier Systems

    SciTech Connect

    Guo, Shengmin; Yang, Shizhong; Khosravi, Ebrahim

    2012-10-01

    This project (10/01/2010-9/30/2013), “Computational Design and Experimental Validation of New Thermal Barrier Systems”, originates from Louisiana State University (LSU) Mechanical Engineering Department and Southern University (SU) Department of Computer Science. This project will directly support the technical goals specified in DEFOA- 0000248, Topic Area 3: Turbine Materials, by addressing key technologies needed to enable the development of advanced turbines and turbine-based systems that will operate safely and efficiently using coal-derived synthesis gases. We will develop and implement novel molecular dynamics method to improve the efficiency of simulation on novel TBC materials; perform high performance computing (HPC) on complex TBC structures to screen the most promising TBC compositions; perform material characterizations and oxidation/corrosion tests; and demonstrate our new thermal barrier coating (TBC) systems experimentally under integrated gasification combined cycle (IGCC) environments. The durability of the coating will be examined using the proposed Durability Test Rig.

  5. Thermal and Environmental Barrier Coatings for Advanced Propulsion Engine Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Miller, Robert A.

    2004-01-01

    Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. For future high performance engines, the development of advanced ceramic barrier coating systems will allow these coatings to be used to simultaneously increase engine operating temperature and reduce cooling requirements, thereby leading to significant improvements in engine power density and efficiency. In order to meet future engine performance and reliability requirements, the coating systems must be designed with increased high temperature stability, lower thermal conductivity, and improved thermal stress and erosion resistance. In this paper, ceramic coating design and testing considerations will be described for high temperature and high-heat-flux engine applications in hot corrosion and oxidation, erosion, and combustion water vapor environments. Further coating performance and life improvements will be expected by utilizing advanced coating architecture design, composition optimization, and improved processing techniques, in conjunction with modeling and design tools.

  6. Prototype Engineered Barrier System Field Tests; Progress report

    SciTech Connect

    Ramirez, A.L.; Beatty, J.; Buscheck, T.A.; Carlson, R.; Daily, W.; LaTorre, V.R.; Lee, K.; Lin, Wunan; Mao, Nai-hsien; Nitao, J.J.; Towse, D.; Ueng, Tzou-Shin; Watwood, D.; Wilder, D.

    1989-07-26

    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.

  7. Computational Design and Experimental Validation of New Thermal Barrier Systems

    SciTech Connect

    Guo, Shengmin; Yang, Shizhong; Khosravi, Ebrahim

    2014-04-01

    This project (10/01/2010-9/30/2014), “Computational Design and Experimental Validation of New Thermal Barrier Systems”, originates from Louisiana State University (LSU) Mechanical Engineering Department and Southern University (SU) Department of Computer Science. This project will directly support the technical goals specified in DE-FOA-0000248, Topic Area 3: Turbine Materials, by addressing key technologies needed to enable the development of advanced turbines and turbine-based systems that will operate safely and efficiently using coal-derived synthesis gases. In this project, the focus is to develop and implement novel molecular dynamics method to improve the efficiency of simulation on novel TBC materials; perform high performance computing (HPC) on complex TBC structures to screen the most promising TBC compositions; perform material characterizations and oxidation/corrosion tests; and demonstrate our new thermal barrier coating (TBC) systems experimentally under integrated gasification combined cycle (IGCC) environments.

  8. Assessing Controls on the Geometry and Dimensions of Modern Barrier Islands

    NASA Astrophysics Data System (ADS)

    Mulhern, J.; Johnson, C. L.; Martin, J. M.

    2015-12-01

    Barrier islands are highly ephemeral features, shaped by wave, tide, and storm energy. The processes that govern the size, shape, and motion of barrier islands are not well constrained, yet central to coastal dynamics. While the global distribution of barrier islands has been mapped and assessed, there is little consensus on the forces controlling barrier island formation, motion, or preservation. This study presents a new semi-global database of modern barrier islands to better understand their morphology and spatial distribution. We have mapped, in Google Earth, the subaerial extent of >350 barrier islands and spits, measuring spatial characteristic such as exposed area, perimeter, length, and width. These objects are cross-referenced with parameters that potentially control morphology, including tidal range, wave height, climate, distance from the continental shelf, proximity to fluvial output, and tectonic setting. This approach provides a more optimal framework to assess controls on coastal features, including barrier island morphology, and to investigate potential geometric scaling relationships. Preliminary analysis shows trends in the spatial characteristics of barrier islands. There is a strong linear relationship between the perimeter and length (y= -0.59 + 0.42x, R2=0.95). Linear trends also relate length to area when the data are separated by tidal range to wave height ratio. Assessment of barrier island shape supports the hypothesis of Hayes (1979) that barrier islands in wave-dominated settings are long and linear while those in mixed energy setting are more rounded. The barrier islands of the Texas Gulf of Mexico are larger than the global average for the database, with distinctly longer length values (41.16 km vs. 15.77 km respectively) and larger areas (103.81 km2 vs. 42.14 km2 respectively). Initial assessment shows that tidal range and wave height are primary controls barrier island dimensions. Future work will consider climate, latitude, fluvial

  9. Assessment of diaper-clogging potential of petrolatum moisture barriers.

    PubMed

    Zehrer, Cindy L; Newman, Diane K; Grove, Gary L; Lutz, James B

    2005-12-01

    Petrolatum-based ointments often are used to treat and prevent incontinence dermatitis. However, anecdotal reports indicate that petrolatum ointments may affect the absorbency of disposable briefs also commonly used in incontinence management. To examine whether petrolatum ointments clog a commonly used absorbent brief, a randomized, balanced-block design study was conducted in a controlled laboratory setting to compare the brief-clogging potential of three petrolatum ointments to a non-alcohol barrier film. Test products were applied to 6-cm x 6-cm test sites on the volar forearms of 16 volunteers. Pre-weighed mini briefs were applied to the test sites in a manner that simulates normal brief wear. After 5 minutes of wear, the mini briefs were weighed to determine percent of product transfer from skin to mini brief. The mini briefs then were reapplied to the same test sites and a synthetic urine solution was introduced between the skin and the mini brief. Mini briefs subsequently were removed to determine fluid uptake by weight. Results indicate significant differences between the four test products (P < 0.01) both in percent transfer and in mini brief fluid absorption. From 59% to 69% of the petrolatum-based products transferred from the skin to the mini briefs and a 54% to 90% reduction in fluid uptake was noted, as determined by weight. The non-alcohol barrier film did not transfer to the mini brief and fluid uptake was minimally affected. Further study in the clinical and practice settings to determine the effect and consequences of barrier product transfer on absorbent garments is warranted.

  10. TRITIUM BARRIER MATERIALS AND SEPARATION SYSTEMS FOR THE NGNP

    SciTech Connect

    Sherman, S; Thad Adams, T

    2008-07-17

    Contamination of downstream hydrogen production plants or other users of high-temperature heat is a concern of the Next Generation Nuclear Plant (NGNP) Project. Due to the high operating temperatures of the NGNP (850-900 C outlet temperature), tritium produced in the nuclear reactor can permeate through heat exchangers to reach the hydrogen production plant, where it can become incorporated into process chemicals or the hydrogen product. The concentration limit for tritium in the hydrogen product has not been established, but it is expected that any future limit on tritium concentration will be no higher than the air and water effluent limits established by the NRC and the EPA. A literature survey of tritium permeation barriers, capture systems, and mitigation measures is presented and technologies are identified that may reduce the movement of tritium to the downstream plant. Among tritium permeation barriers, oxide layers produced in-situ may provide the most suitable barriers, though it may be possible to use aluminized surfaces also. For tritium capture systems, the use of getters is recommended, and high-temperature hydride forming materials such as Ti, Zr, and Y are suggested. Tritium may also be converted to HTO in order to capture it on molecular sieves or getter materials. Counter-flow of hydrogen may reduce the flux of tritium through heat exchangers. Recommendations for research and development work are provided.

  11. Implementation of electronic data capture systems: barriers and solutions.

    PubMed

    Welker, James A

    2007-05-01

    Although increasing in pace, the conversion to Electronic Data Capture (EDC) has been a slow progression. The use of EDC systems should confer improved data integrity, cost savings and a shorter time to study database closure. This will reduce the time to market and cost of new medications. With the current sentiment of the industry suggesting the cost analysis has been accepted to be in favor of EDC, the likely limitation to disseminated use is an inability to implement these systems. If the leadership at the sponsor, clinical research organization and investigator site is cognizant of the barriers to implementation, they can anticipate and mitigate them prior to the users becoming disgruntled and resistant to the new method of data capture. Once understood, barriers such as user input, technical support, user motivation, regulatory requirements, communication with users, timing of implementation, software installation, graphical user interface, identification of bridgers, patient participation, availability of technology, and costs can be better addressed at the beginning of the implementation process and successfully averted. This review discusses these barriers and potential solutions that can assist the clinical trial industry in achieving more wide-spread EDC use and the resulting improvement in operating efficiencies.

  12. Evaluation of Oxidation Damage in Thermal Barrier Coating Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    1996-01-01

    A method based on the technique of dilatometry has been established to quantitatively evaluate the interfacial damage due to the oxidation in a thermal barrier coating system. Strain isolation and adhesion coefficients have been proposed to characterize the thermal barrier coating (TBC) performance based on its thermal expansion behavior. It has been found that, for a thermal barrier coating system consisting of ZrO2-8%Y2O3/FeCrAlY/4140 steel substrate, the oxidation of the bond coat and substrate significantly reduced the ceramic coating adherence, as inferred from the dilatometry measurements. The in-situ thermal expansion measurements under 30 deg C to 700 deg C thermal cycling in air showed that the adhesion coefficient, A(sub i) decreased by 25% during the first 35 oxidation cycles. Metallography showed that delamination occurred at both the ceramic/bond coat and bond coat/substrate interfaces. In addition, the strain isolation effect has been improved by increasing the FeCrAlY bond coat thickness. The strain isolation coefficient, Si, increased from about 0.04 to 0.25, as the bond coat thickness changed from 0.1 mm to 1.0 mm. It may be possible to design optimum values of strain isolation and interface adhesion coefficients to achieve the best TBC performance.

  13. Computational design and experimental validation of new thermal barrier systems

    SciTech Connect

    Guo, Shengmin

    2015-03-31

    The focus of this project is on the development of a reliable and efficient ab initio based computational high temperature material design method which can be used to assist the Thermal Barrier Coating (TBC) bond-coat and top-coat design. Experimental evaluations on the new TBCs are conducted to confirm the new TBCs’ properties. Southern University is the subcontractor on this project with a focus on the computational simulation method development. We have performed ab initio density functional theory (DFT) method and molecular dynamics simulation on screening the top coats and bond coats for gas turbine thermal barrier coating design and validation applications. For experimental validations, our focus is on the hot corrosion performance of different TBC systems. For example, for one of the top coatings studied, we examined the thermal stability of TaZr2.75O8 and confirmed it’s hot corrosion performance.

  14. Acoustic emission assessment of interface cracking in thermal barrier coatings

    NASA Astrophysics Data System (ADS)

    Yang, Li; Zhong, Zhi-Chun; Zhou, Yi-Chun; Zhu, Wang; Zhang, Zhi-Biao; Cai, Can-Ying; Lu, Chun-Sheng

    2016-04-01

    In this paper, acoustic emission (AE) and digital image correlation methods were applied to monitor interface cracking in thermal barrier coatings under compression. The interface failure process can be identified via its AE features, including buckling, delamination incubation and spallation. According to the Fourier transformation of AE signals, there are four different failure modes: surface vertical cracks, opening and sliding interface cracks, and substrate deformation. The characteristic frequency of AE signals from surface vertical cracks is 0.21 MHz, whilst that of the two types of interface cracks are 0.43 and 0.29 MHz, respectively. The energy released of the two types of interface cracks are 0.43 and 0.29 MHz, respectively. Based on the energy released from cracking and the AE signals, a relationship is established between the interface crack length and AE parameters, which is in good agreement with experimental results.

  15. Assessment of multireference perturbation methods for chemical reaction barrier heights.

    PubMed

    Fracchia, Francesco; Cimiraglia, Renzo; Angeli, Celestino

    2015-05-28

    A few flavors of multireference perturbation theory, two variants of the n-electron valence state perturbation theory and two of the complete active space perturbation theory, are here tested for the calculation of barrier heights for the set of chemical reactions included in the DBH24/08 database, for which very accurate values are available. The comparison of the results obtained with these approaches with those already published for other theoretical models indicates that multireference perturbation theory is a valuable tool for the description of a chemical reaction. Moreover, limiting the comparison to the perturbation theory approaches, one observes that the bad behavior found for single reference methods (such as Møller-Plesset to second and fourth order in the energy) is markedly improved upon moving to the multireference generalizations.

  16. A TEM protocol for quality assurance of in vitro cellular barrier models and its application to the assessment of nanoparticle transport mechanisms across barriers.

    PubMed

    Ye, Dong; Dawson, Kenneth A; Lynch, Iseult

    2015-01-01

    We report here a protocol to characterise and monitor the quality of in vitro human cellular barrier models using Transmission Electron Microscopy (TEM), which can be applied for transport assays, mechanistic studies and screening of drug/compound (including nanoparticle) penetration across such biological barriers. Data from two examples of biological barriers are given, namely the hCMEC/D3 endothelial blood-brain barrier model, and the Caco-2 intestinal epithelial barrier model, to show the general applicability of the method. Several aspects of this method are applicable to the quality assurance of in vitro barrier models, e.g., assessment of the multi or mono-layer structure of the endothelial cells; identification of any potential "holes" in the barrier that could confound transport assay results; validation of tight junction expression; and determination of the types and amounts of key cellular organelles present in the barrier to account for any significant changes in phenotype that may occur compared to the in vivo situation. The method described here provides a key advantage in that it prevents loss of the filter membrane during monolayer sectioning, thereby preserving critical details associated with the basal cell membrane. Applicability of the protocol for other in vitro biological barriers, such as the blood-foetus, blood-testes, blood-cerebrospinal fluid (CSF) and lung alveolar-capillary barriers is also discussed. Additionally, we demonstrate the use of the method for assessment of nanoparticle transport across cellular barriers and elucidation of transcytosis mechanisms. Sequential events of cellular endocytosis, localisation and transcytosis can be described in detail by TEM imaging, revealing useful sub-cellular details that provide evidence for the mechanism of nanoparticle transport in the hCMEC/D3 blood-brain barrier model and the Caco-2 intestinal epithelial cell model. Potential artefacts resulting from the nanoparticles interacting with the

  17. Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.

    2000-01-01

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

  18. Microstructural Evolution and Interfacial Motion in Systems with Diffusion Barriers

    SciTech Connect

    William C. Johnson

    2007-06-30

    The initial goal of this research program was to model and to simulate phase transformations in systems containing diffusion barriers. The modeling work included the development and testing of code to describe mass flow, the kinetics of phase formation, elastic deformation, and subsequent microstructural evolution occurring during interdiffusion. The primary simulation tools to be used were a class of diffuse interface methods described by the Cahn-Hilliard and phase field equations for the temporal and spatial evolution of the composition and deformation fields and other relevant phase variables. One-dimensional analytical solutions were also to be developed both to test the numerical methods and to establish connections to physical systems. During the early stages of the research program, two new areas of research related to systems with diffusion barriers were identified. The first area concerned phase formation and diffusional phase transformations in reacting systems subject to high electric current densities. Such high-current environments are common in lead-free solders, for example, and have important technological applications. The second area was an offshoot of the present work, and concerned theoretical modeling of phase evolution and cyclical amorphization of metallic alloys during ball milling.

  19. Towards a barrier height benchmark set for biologically relevant systems

    PubMed Central

    Kromann, Jimmy C.; Christensen, Anders S.; Cui, Qiang

    2016-01-01

    We have collected computed barrier heights and reaction energies (and associated model structures) for five enzymes from studies published by Himo and co-workers. Using this data, obtained at the B3LYP/6- 311+G(2d,2p)[LANL2DZ]//B3LYP/6-31G(d,p) level of theory, we then benchmark PM6, PM7, PM7-TS, and DFTB3 and discuss the influence of system size, bulk solvation, and geometry re-optimization on the error. The mean absolute differences (MADs) observed for these five enzyme model systems are similar to those observed for PM6 and PM7 for smaller systems (10–15 kcal/mol), while DFTB results in a MAD that is significantly lower (6 kcal/mol). The MADs for PMx and DFTB3 are each dominated by large errors for a single system and if the system is disregarded the MADs fall to 4–5 kcal/mol. Overall, results for the condensed phase are neither more or less accurate relative to B3LYP than those in the gas phase. With the exception of PM7-TS, the MAD for small and large structural models are very similar, with a maximum deviation of 3 kcal/mol for PM6. Geometry optimization with PM6 shows that for one system this method predicts a different mechanism compared to B3LYP/6-31G(d,p). For the remaining systems, geometry optimization of the large structural model increases the MAD relative to single points, by 2.5 and 1.8 kcal/mol for barriers and reaction energies. For the small structural model, the corresponding MADs decrease by 0.4 and 1.2 kcal/mol, respectively. However, despite these small changes, significant changes in the structures are observed for some systems, such as proton transfer and hydrogen bonding rearrangements. The paper represents the first step in the process of creating a benchmark set of barriers computed for systems that are relatively large and representative of enzymatic reactions, a considerable challenge for any one research group but possible through a concerted effort by the community. We end by outlining steps needed to expand and improve the data

  20. Towards a barrier height benchmark set for biologically relevant systems.

    PubMed

    Kromann, Jimmy C; Christensen, Anders S; Cui, Qiang; Jensen, Jan H

    2016-01-01

    We have collected computed barrier heights and reaction energies (and associated model structures) for five enzymes from studies published by Himo and co-workers. Using this data, obtained at the B3LYP/6- 311+G(2d,2p)[LANL2DZ]//B3LYP/6-31G(d,p) level of theory, we then benchmark PM6, PM7, PM7-TS, and DFTB3 and discuss the influence of system size, bulk solvation, and geometry re-optimization on the error. The mean absolute differences (MADs) observed for these five enzyme model systems are similar to those observed for PM6 and PM7 for smaller systems (10-15 kcal/mol), while DFTB results in a MAD that is significantly lower (6 kcal/mol). The MADs for PMx and DFTB3 are each dominated by large errors for a single system and if the system is disregarded the MADs fall to 4-5 kcal/mol. Overall, results for the condensed phase are neither more or less accurate relative to B3LYP than those in the gas phase. With the exception of PM7-TS, the MAD for small and large structural models are very similar, with a maximum deviation of 3 kcal/mol for PM6. Geometry optimization with PM6 shows that for one system this method predicts a different mechanism compared to B3LYP/6-31G(d,p). For the remaining systems, geometry optimization of the large structural model increases the MAD relative to single points, by 2.5 and 1.8 kcal/mol for barriers and reaction energies. For the small structural model, the corresponding MADs decrease by 0.4 and 1.2 kcal/mol, respectively. However, despite these small changes, significant changes in the structures are observed for some systems, such as proton transfer and hydrogen bonding rearrangements. The paper represents the first step in the process of creating a benchmark set of barriers computed for systems that are relatively large and representative of enzymatic reactions, a considerable challenge for any one research group but possible through a concerted effort by the community. We end by outlining steps needed to expand and improve the data set

  1. Qualitative Assessment across Language Barriers: An Action Research Study

    ERIC Educational Resources Information Center

    Cronje, Johannes C.

    2009-01-01

    If students cannot express themselves in the language of the assessor, and if the assessor is not familiar with the cultural constraints within which students operate, it is difficult for the assessor to collect evidence of adequate performance. This article describes the assessment of three digital artefacts where the assessor strove to…

  2. Failure Mechanism for Thermal Fatigue of Thermal Barrier Coating Systems

    NASA Astrophysics Data System (ADS)

    Giolli, C.; Scrivani, A.; Rizzi, G.; Borgioli, F.; Bolelli, G.; Lusvarghi, L.

    2009-06-01

    Thick thermal barrier coatings (TBCs), consisting of a CoNiCrAlY bond coat and yttria-partially stabilized zirconia top coat with different porosity values, were produced by air plasma spray (APS). The thermal fatigue resistance limit of the TBCs was tested by furnace cycling tests (FCT) according to the specifications of an original equipment manufacturer (OEM). The morphology, residual stresses, and micromechanical properties (microhardness, indentation fracture toughness) of the TBC systems before and after FCT were analyzed. The thermal fatigue resistance increases with the amount of porosity in the top coat. The compressive in-plane stresses increase in the TBC systems after thermal cycling; nevertheless the increasing rate has a trend contrary to the porosity level of top coat. The data suggest that the spallation happens at the TGO/top coat interface. The failure mechanism of thick TBCs was found to be similar to that of conventional thin TBC systems made by APS.

  3. Computational Design and Experimental Validation of New Thermal Barrier Systems

    SciTech Connect

    Guo, Shengmin; Yang, Shizhong; Khosravi, Ebrahim

    2011-12-31

    This project (10/01/2010-9/30/2013), “Computational Design and Experimental Validation of New Thermal Barrier Systems”, originates from Louisiana State University (LSU) Mechanical Engineering Department and Southern University (SU) Department of Computer Science. This proposal will directly support the technical goals specified in DE-FOA-0000248, Topic Area 3: Turbine Materials, by addressing key technologies needed to enable the development of advanced turbines and turbine-based systems that will operate safely and efficiently using coal-derived synthesis gases. We will develop novel molecular dynamics method to improve the efficiency of simulation on novel TBC materials; we will perform high performance computing (HPC) on complex TBC structures to screen the most promising TBC compositions; we will perform material characterizations and oxidation/corrosion tests; and we will demonstrate our new Thermal barrier coating (TBC) systems experimentally under Integrated gasification combined cycle (IGCC) environments. The durability of the coating will be examined using the proposed High Temperature/High Pressure Durability Test Rig under real syngas product compositions.

  4. Identifying Barriers in Implementing Outcomes-Based Assessment Program Review: A Grounded Theory Analysis

    ERIC Educational Resources Information Center

    Bresciani, Marilee J.

    2011-01-01

    The purpose of this grounded theory study was to identify the typical barriers encountered by faculty and administrators when implementing outcomes-based assessment program review. An analysis of interviews with faculty and administrators at nine institutions revealed a theory that faculty and administrators' promotion, tenure (if applicable),…

  5. Creating an Outcomes-Based Tool for Learning Barrier Assessment in an Outpatient Education Program.

    ERIC Educational Resources Information Center

    Hernandez, Teri L.; Rupnow, Jana M.; Currie, Kristi A.; Procious, James K.; Adams, Jenny

    2003-01-01

    An outcomes-based assessment instrument was devised to screen patients for learning problems that would impede patient education in cardiac rehabilitation. Criteria for seven barriers were established: hearing, language, cultural, religious, vision, cognitive, emotional). Points of data collection and a rationale for collection were identified.…

  6. Assessing a landscape barrier using genetic simulation modelling: implications for raccoon rabies management.

    PubMed

    Rees, Erin E; Pond, Bruce A; Cullingham, Catherine I; Tinline, Rowland; Ball, David; Kyle, Christopher J; White, Bradley N

    2008-08-15

    Landscape barriers influence movement patterns of animals, which in turn, affect spatio-temporal spread of infectious wildlife disease. We compare genetic data from computer simulations to those acquired from field samples to measure the effect of a landscape barrier on raccoon (Procyon lotor) movement, enabling risk assessment of raccoon rabies disease spread across the Niagara River from New York State into Ontario, an area currently uninfected by rabies. An individual-based spatially explicit model is used to simulate the expansion of a raccoon population to cross the Niagara River, for different permeabilities of the river to raccoon crossings. Since the model records individual raccoon genetics, the genetic population structure of neutral mitochondrial DNA haplotypes are characterised in the expanding population, every 25 years, using a genetic distance measure, phi ST, Mantel tests and a gene diversity measure. The river barrier effect is assessed by comparing genetic measures computed from model outputs to those calculated from 166 raccoons recently sampled from the same landscape. The "best fit" between modelled scenarios and field data indicate the river prevents 50% of attempts to cross the river. Founder effects dominated the colonizing genetic population structure, and, as the river barrier effect increased, its genetic diversity decreased. Using gene flow to calibrate the effect of the river as a barrier to movement provides an estimate of the effect of a river in reducing the likelihood of cross-river infection. Including individual genetic markers in simulation modelling benefits investigations of disease spread and control.

  7. Risk Assessment System

    NASA Technical Reports Server (NTRS)

    1993-01-01

    FEAT, a software system for evaluating risks, was developed by Lockheed and later enhanced under NASA funding. FEAT uses directed graph - or digraph - models to provide information on cause and effect if a set of failure events occurs. James Miller, the program designer at Lockheed, formed DiGraphics, Inc. to market the software that has evolved from FEAT. The Diquest Analyzer, the company's flagship product, assists product designers in identifying the redundancies and weaknesses of a system. The software has applications in the chemical industry for risk assessment, design evaluation, and change management. Additional markets have been found in operations monitoring diagnostics and training of new personnel.

  8. Initial Assessment of Environmental Barrier Coatings for the Prometheus Project

    SciTech Connect

    M. Frederick

    2005-12-15

    Depending upon final design and materials selections, a variety of engineering solutions may need to be considered to avoid chemical degradation of components in a notional space nuclear power plant (SNPP). Coatings are one engineered approach that was considered. A comprehensive review of protective coating technology for various space-reactor structural materials is presented, including refractory metal alloys [molybdenum (Mo), tungsten (W), rhenium (Re), tantalum (Ta), and niobium (Nb)], nickel (Ni)-base superalloys, and silicon carbide (Sic). A summary description of some common deposition techniques is included. A literature survey identified coatings based on silicides or iridium/rhenium as the primary methods for environmental protection of refractory metal alloys. Modified aluminide coatings have been identified for superalloys and multilayer ceramic coatings for protection of Sic. All reviewed research focused on protecting structural materials from extreme temperatures in highly oxidizing conditions. Thermodynamic analyses indicate that some of these coatings may not be protective in the high-temperature, impure-He environment expected in a Prometheus reactor system. Further research is proposed to determine extensibility of these coating materials to less-oxidizing or neutral environments.

  9. Barrier RF system and applications in Main Injector

    SciTech Connect

    Chou, W.; Wildman, D.; Takagi, A.; Zheng, H.; /Caltech

    2005-05-01

    A novel broadband RF system--the barrier RF--has been designed, fabricated and installed in the Fermilab Main Injector (MI). It uses nanocrystal magnetic alloy called Finemet and high voltage fast MOSFET switches. The system delivers {+-}10 kV square pulses at 90 kHz. It can stack two proton batches injected from the Booster and squeeze them into the size of one so that the bunch intensity is increased. The high intensity beams have been successfully accelerated to 120 GeV with small losses. The problem of large longitudinal emittance growth is under investigation. A second system will be installed during the fall shutdown and be tested for the so-called fast stacking scheme to continuously stack up to 12 Booster batches in the MI. This system is also used for cleaning up the leaking-out dc beams from slip stacking to reduce beam loss. This work is part of the US-Japan collaborative agreement.

  10. Advanced thermal barrier coating system development. Technical progress report, June 1, 1996--July 31, 1996

    SciTech Connect

    1996-08-07

    An improved thermal barrier coating system with good reliability and thermal performance is described. The report discusses the coating process, manufacturing, repair, deposition, and microstructure of the coatings.

  11. Nanoscale drug delivery systems and the blood-brain barrier.

    PubMed

    Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

    2014-01-01

    The protective properties of the blood-brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain's vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual's age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS.

  12. Nanoscale drug delivery systems and the blood–brain barrier

    PubMed Central

    Alyautdin, Renad; Khalin, Igor; Nafeeza, Mohd Ismail; Haron, Muhammad Huzaimi; Kuznetsov, Dmitry

    2014-01-01

    The protective properties of the blood–brain barrier (BBB) are conferred by the intricate architecture of its endothelium coupled with multiple specific transport systems expressed on the surface of endothelial cells (ECs) in the brain’s vasculature. When the stringent control of the BBB is disrupted, such as following EC damage, substances that are safe for peripheral tissues but toxic to neurons have easier access to the central nervous system (CNS). As a consequence, CNS disorders, including degenerative diseases, can occur independently of an individual’s age. Although the BBB is crucial in regulating the biochemical environment that is essential for maintaining neuronal integrity, it limits drug delivery to the CNS. This makes it difficult to deliver beneficial drugs across the BBB while preventing the passage of potential neurotoxins. Available options include transport of drugs across the ECs through traversing occludins and claudins in the tight junctions or by attaching drugs to one of the existing transport systems. Either way, access must specifically allow only the passage of a particular drug. In general, the BBB allows small molecules to enter the CNS; however, most drugs with the potential to treat neurological disorders other than infections have large structures. Several mechanisms, such as modifications of the built-in pumping-out system of drugs and utilization of nanocarriers and liposomes, are among the drug-delivery systems that have been tested; however, each has its limitations and constraints. This review comprehensively discusses the functional morphology of the BBB and the challenges that must be overcome by drug-delivery systems and elaborates on the potential targets, mechanisms, and formulations to improve drug delivery to the CNS. PMID:24550672

  13. Safety assessment of discharge chute isolation barrier preparation and installation activities. Revision 3

    SciTech Connect

    Meichle, R.H.

    1994-11-08

    This revision adds a section addressing impacts of dropping surfacing tool and rack cutter on the basin floor, and corrects typographical errors. The safety assessment is made for the activities for the preparation and installation of the discharge chute isolation barriers. The safety assessment includes a hazard assessment and comparisons of potential accidents/events to those addressed by the current safety basis documentation. No significant hazards were identified. An evaluation against the USQ evaluation questions was made and the determination made that the activities do not represent a USQ. Hazard categorization techniques were used to provide a basis for readiness review classifications.

  14. A Temporal Assessment of Barrier Island Vulnerability to Extreme Wave Events, Virginia Coast Reserve

    NASA Astrophysics Data System (ADS)

    Oster, D. J.; Moore, L. J.; Doran, K. J.; Stockdon, H. F.

    2010-12-01

    Barrier island vulnerability to storm-generated waves is directly related to interactions between shoreface morphology and surf-zone dynamics. During storms, the seaward-most dune often limits the landward extent of wave energy; however, if maximum wave run-up exceeds the elevation of the top of the dune, overwash or inundation may occur. The ‘Storm Impact Scale’ presented by Sallenger (2000) classifies barrier beach vulnerability to individual storm events based on the elevation of the frontal dune crest and toe relative to maximum wave run-up. Changes to the dune and beachface can occur over a range of time scales, altering local vulnerability to extreme waves from storms, even as a storm is occurring. As sea level continues to rise, barrier beaches will become increasingly vulnerable to overwash and inundation from a greater number of storms. Our objective is to assess temporal trends in barrier island vulnerability while also exploring island-chain-wide response and recovery from two notably different storm events (Nor’Ida and Hurricane Bonnie) along the undeveloped barrier islands of the Virginia Coast Reserve (VCR). We compare shoreline position and elevations of the frontal dune crest (DHIGH) and dune toe (DLOW) across four lidar data sets collected between 1998-2010. Observed significant wave height and period from the National Data Buoy Center and the Duck, NC Field Research Facility for the time period between 1985 and 2009 are classified to represent one-year, five-year, and ten-year storm events that serve as the basis for comparison of island vulnerability through time to a range of storm severity. Initial results reveal significant spatial and temporal variation in barrier island vulnerability to storms throughout the VCR. Despite the range of variability, all three beach features (i.e., shoreline position, DHIGH and DLOW), have moved landward indicating large-scale, widespread migration, or narrowing, of VCR barrier island landforms over the

  15. Cost of radon-barrier systems for uranium mill tailings

    SciTech Connect

    Baker, E.G.; Hartley, J.N.

    1982-08-01

    This report deals specifically with the cost of three types of radon barrier systems, earthen covers, asphalt emulsion covers, and multilayer covers, which could meet standards proposed by the Environmental Protection Agency to stabilize uranium mill tailings located primarily in the western US. In addition, the report includes a sensitivity analysis of various factors which significantly effect the overall cost of the three systems. These analyses were based on a generic disposal site. Four different 3m thick earthen covers were tested and cost an average of $27/m/sup 2/. The least expensive earthen cover cost was about $21/m/sup 2/. The asphalt cover system (6 to 7 cm of asphalt topped with 0.6m of overburden) cost about $28/m/sup 2/. The four multilayer covers averaged $57/m/sup 2/, but materials handling problems encountered during the test inflated this cost above what was anticipated and significant cost reductions should be possible. The least expensive multilayer cover cost $43/m/sup 2/. Based on the results of the Grand Junction field test we estimated the cost of covering the tailings from three high priority sites, Durango, Shiprock, and Salt Lake City (Vitro). The cost of a 3m earthen cover ranged from $18 to 33/m/sup 2/ for the seven disposal sites (two or three at each location) studied. The cost of asphalt cover systems were $23 to 28/m/sup 2/ and the multilayer cover costs were between $31 to 36/m/sup 2/. The earthen cover costs are less than the Grand Junction field test cost primarily because cover material is available at or near most of the disposal sites selected. Earthen material was imported from 6 to 10 miles for the field test. Assuming more efficienct utilization of materials significantly reduced the cost of the multilayer covers.

  16. Analysis of uncertainties in α -particle optical-potential assessment below the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Avrigeanu, V.; Avrigeanu, M.

    2016-08-01

    Background: Recent high-precision measurements of α -induced reaction data below the Coulomb barrier have pointed out questions about the α -particle optical-model potential (OMP) which are still unanswered within various mass ranges. Purpose: The applicability of previous optical potential and eventual uncertainties and/or systematic errors of the OMP assessment at low energies can be further considered on this basis. Method: Nuclear model parameters based on the analysis of recent independent data, particularly γ -ray strength functions, have been involved within statistical model calculation of the (α ,x ) reaction cross sections. Results: The above-mentioned potential provides a consistent description of the recent α -induced reaction data with no empirical rescaling factors of the γ and/or nucleon widths. Conclusions: A suitable assessment of α -particle optical potential below the Coulomb barrier should involve the statistical-model parameters beyond this potential on the basis of a former analysis of independent data.

  17. System Assessment Standards: Defining the Market for Industrial Energy Assessments

    SciTech Connect

    Sheaffer, Paul; McKane, Aimee; Tutterow, Vestal; Crane, Ryan

    2009-08-01

    Improved efficiency of industrial systems (e.g., compressed air or steam) contributes to a manufacturing facility?s bottom line, improves reliability, and better utilizes assets. Despite these advantages, many industrial facilities continue to have unrealized system optimization potential. A barrier to realizing this potential is the lack of market definition for system energy efficiency assessment services, creating problems for both service providers in establishing market value for their services and for consumers in determining the relative quality of these system assessment services. On August 19, 2008, the American Society of Mechanical Engineers (ASME) issued four new draft Standards for trial use that are designed to raise the bar and define the market for these services. These draft Standards set the requirements for conducting an energy assessment at an industrial facility for four different system types: compressed air, process heating, pumping, and steam. The Standards address topics such as organizing and conducting assessments; analyzing the data collected; and reporting and documentation. This paper addresses both the issues and challenges in developing the Standards and the accompanying Guidance Documents, as well as the result of field testing by industrial facilities, consultants, and utilities during the trial use period that ended in January, 2009. These Standards will be revised and released by ASME for public review, and subsequently submitted for approval as American National Standards for publication in late 2009. Plans for a related activity to establish a professional-level program to certify practitioners in the area of system assessments, opportunities to integrate the ASME Standards with related work on industrial energy efficiency, as well as plans to expand the system assessment Standard portfolio are also discussed.

  18. Numerical heat transfer attic model using a radiant barrier system

    SciTech Connect

    Moujaes, S.F.; Alsaiegh, N.T.

    2000-04-01

    A two-dimensional, steady-state finite-element model was developed to simulate the thermal effects of the application of an attic radiant barrier system (ARBS) inside a ventilated residential attic. The attic is ventilated using the exhaust air from an evaporative cooler. The study uses a {kappa}-{epsilon} turbulent model to describe the velocity and temperature distributions in the attic. The ambient temperature and solar isolation densities on the outside inclined attic surfaces are used as driving functions for the model. The model also included the appropriate heat exchange modes of convection and radiation on these outside surfaces. Several recirculation zones were visually observed in the attic flow pattern. Also, the use of the ARBS seems to lower the heat transfer through the ceiling by 25--30%, but this effect decreases significantly as the outside ventilation rates are increased through the attic space. The 2D model revealed some interesting temperature distributions along the attic surfaces that could not have been predicted by the one-dimensional models. The lower emissivity ARBS seems to raise the temperature of the inclined attic surfaces as well as the temperature of the exhausted ventilation air.

  19. Engineered Barrier Systems Thermal-Hydraulic-Chemical Column Test Report

    SciTech Connect

    W.E. Lowry

    2001-12-13

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

  20. ARCTIC FOUNDATIONS, INC. FREEZE BARRIER SYSTEM - SITE TECHNOLOGY CAPSULE

    EPA Science Inventory

    Arctic Foundations, Inc. (AFI), of Anchorage, Alaska has developed a freeze barrier technology designed to prevent the migration of contaminants in groundwater by completely isolating contaminant source areas until appropriate remediation techniques can be applied. With this tec...

  1. Interdisciplinary barriers: An impediment to the effective application of systems engineering

    NASA Technical Reports Server (NTRS)

    Harrison, E., Jr.

    1971-01-01

    Interdisciplinary transfer of information and technology does not occur very readily, even for system planners, because of the existence of some very real barriers. These barriers to flow of information and technology between disciplines represent one of the important difficulties associated with the application of systems analysis to many problems. The nature and characteristics of some of these barriers are enumerated and discussed in detail. A number of methodologies and techniques which have been specifically developed to aid in the transfer of technology and information across these interdisciplinary barriers is examined.

  2. Assessing transmissible spongiform encephalopathy species barriers with an in vitro prion protein conversion assay

    USGS Publications Warehouse

    Johnson, Christopher J.; Carlson, Christina M.; Morawski, Aaron R.; Manthei, Alyson; Cashman, Neil R.

    2015-01-01

    Studies to understanding interspecies transmission of transmissible spongiform encephalopathies (TSEs, prion diseases) are challenging in that they typically rely upon lengthy and costly in vivo animal challenge studies. A number of in vitro assays have been developed to aid in measuring prion species barriers, thereby reducing animal use and providing quicker results than animal bioassays. Here, we present the protocol for a rapid in vitroprion conversion assay called the conversion efficiency ratio (CER) assay. In this assay cellular prion protein (PrPC) from an uninfected host brain is denatured at both pH 7.4 and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with TSE agent, the amount of PrPC that converts to a proteinase K (PK)-resistant state is modulated by the original host’s species barrier to the TSE agent. In contrast, PrPC in the pH 3.5 substrate is misfolded by any TSE agent. By comparing the amount of PK-resistant prion protein in the two substrates, an assessment of the host’s species barrier can be made. We show that the CER assay correctly predicts known prion species barriers of laboratory mice and, as an example, show some preliminary results suggesting that bobcats (Lynx rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting disease agent.

  3. Assessing transmissible spongiform encephalopathy species barriers with an in vitro prion protein conversion assay.

    PubMed

    Johnson, Christopher J; Carlson, Christina M; Morawski, Aaron R; Manthei, Alyson; Cashman, Neil R

    2015-03-10

    Studies to understanding interspecies transmission of transmissible spongiform encephalopathies (TSEs, prion diseases) are challenging in that they typically rely upon lengthy and costly in vivo animal challenge studies. A number of in vitro assays have been developed to aid in measuring prion species barriers, thereby reducing animal use and providing quicker results than animal bioassays. Here, we present the protocol for a rapid in vitro prion conversion assay called the conversion efficiency ratio (CER) assay. In this assay cellular prion protein (PrPC) from an uninfected host brain is denatured at both pH 7.4 and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with TSE agent, the amount of PrPC that converts to a proteinase K (PK)-resistant state is modulated by the original host's species barrier to the TSE agent. In contrast, PrPC in the pH 3.5 substrate is misfolded by any TSE agent. By comparing the amount of PK-resistant prion protein in the two substrates, an assessment of the host's species barrier can be made. We show that the CER assay correctly predicts known prion species barriers of laboratory mice and, as an example, show some preliminary results suggesting that bobcats (Lynx rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting disease agent.

  4. Assessing transmissible spongiform encephalopathy species barriers with an in vitro prion protein conversion assay.

    PubMed

    Johnson, Christopher J; Carlson, Christina M; Morawski, Aaron R; Manthei, Alyson; Cashman, Neil R

    2015-01-01

    Studies to understanding interspecies transmission of transmissible spongiform encephalopathies (TSEs, prion diseases) are challenging in that they typically rely upon lengthy and costly in vivo animal challenge studies. A number of in vitro assays have been developed to aid in measuring prion species barriers, thereby reducing animal use and providing quicker results than animal bioassays. Here, we present the protocol for a rapid in vitro prion conversion assay called the conversion efficiency ratio (CER) assay. In this assay cellular prion protein (PrPC) from an uninfected host brain is denatured at both pH 7.4 and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with TSE agent, the amount of PrPC that converts to a proteinase K (PK)-resistant state is modulated by the original host's species barrier to the TSE agent. In contrast, PrPC in the pH 3.5 substrate is misfolded by any TSE agent. By comparing the amount of PK-resistant prion protein in the two substrates, an assessment of the host's species barrier can be made. We show that the CER assay correctly predicts known prion species barriers of laboratory mice and, as an example, show some preliminary results suggesting that bobcats (Lynx rufus) may be susceptible to white-tailed deer (Odocoileus virginianus) chronic wasting disease agent. PMID:25867521

  5. A suction blister model reliably assesses skin barrier restoration and immune response.

    PubMed

    Smith, Tracey J; Wilson, Marques A; Young, Andrew J; Montain, Scott J

    2015-02-01

    Skin wound healing models can be used to detect changes in immune function in response to interventions. This study used a test-retest format to assess the reliability of a skin suction blister procedure for quantitatively evaluating human immune function in repeated measures type studies. Up to eight suction blisters (~30 mm(2)) were induced via suction on each participant's left and right forearm (randomized order; blister session 1 and 2), separated by approximately one week. Fluid was sampled from each blister, and the top layer of each blister was removed to reveal up to eight skin wounds. Fluid from each wound was collected 4, 7 and 24h after blisters were induced, and proinflammatory cytokines were measured. Transepidermal water loss (TEWL), to assess skin barrier recovery, was measured daily at each wound site until values were within 90% of baseline values (i.e., unbroken skin). Sleep, stress and inflammation (i.e., factors that affect wound healing and immune function), preceding the blister induction, were assessed via activity monitors (Actical, Philips Respironics, Murrysville, Pennsylvania), the Perceived Stress Scale (PSS) and C-reactive protein (CRP), respectively. Area-under-the-curve and TEWL, between blister session 1 and 2, were compared using Pearson correlations and partial correlations (controlling for average nightly sleep, PSS scores and CRP). The suction blister method was considered reliable for assessing immune response and skin barrier recovery if correlation coefficients reached 0.7. Volunteers (n=16; 12 M; 4F) were 23 ± 5 years [mean ± SD]. Time to skin barrier restoration was 4.9 ± 0.8 and 4.8 ± 0.9 days for sessions 1 and 2, respectively. Correlation coefficients for skin barrier restoration, IL-6, IL-8 and MIP-1α were 0.9 (P<0.0001), 0.7 (P=0.008) and 0.9 (P<0.0001), respectively. When average nightly sleep, PSS scores and CRP (i.e., percent difference between sessions 1 and 2) were taken into consideration, correlations in

  6. A suction blister model reliably assesses skin barrier restoration and immune response.

    PubMed

    Smith, Tracey J; Wilson, Marques A; Young, Andrew J; Montain, Scott J

    2015-02-01

    Skin wound healing models can be used to detect changes in immune function in response to interventions. This study used a test-retest format to assess the reliability of a skin suction blister procedure for quantitatively evaluating human immune function in repeated measures type studies. Up to eight suction blisters (~30 mm(2)) were induced via suction on each participant's left and right forearm (randomized order; blister session 1 and 2), separated by approximately one week. Fluid was sampled from each blister, and the top layer of each blister was removed to reveal up to eight skin wounds. Fluid from each wound was collected 4, 7 and 24h after blisters were induced, and proinflammatory cytokines were measured. Transepidermal water loss (TEWL), to assess skin barrier recovery, was measured daily at each wound site until values were within 90% of baseline values (i.e., unbroken skin). Sleep, stress and inflammation (i.e., factors that affect wound healing and immune function), preceding the blister induction, were assessed via activity monitors (Actical, Philips Respironics, Murrysville, Pennsylvania), the Perceived Stress Scale (PSS) and C-reactive protein (CRP), respectively. Area-under-the-curve and TEWL, between blister session 1 and 2, were compared using Pearson correlations and partial correlations (controlling for average nightly sleep, PSS scores and CRP). The suction blister method was considered reliable for assessing immune response and skin barrier recovery if correlation coefficients reached 0.7. Volunteers (n=16; 12 M; 4F) were 23 ± 5 years [mean ± SD]. Time to skin barrier restoration was 4.9 ± 0.8 and 4.8 ± 0.9 days for sessions 1 and 2, respectively. Correlation coefficients for skin barrier restoration, IL-6, IL-8 and MIP-1α were 0.9 (P<0.0001), 0.7 (P=0.008) and 0.9 (P<0.0001), respectively. When average nightly sleep, PSS scores and CRP (i.e., percent difference between sessions 1 and 2) were taken into consideration, correlations in

  7. Morphology and stratigraphy of small barrier-lagoon systems in Maine

    USGS Publications Warehouse

    Duffy, W.; Belknap, D.F.; Kelley, J.T.

    1989-01-01

    The coast of Maine contains over 200 individual barrier-lagoon systems, most quite small, with an aggregate length of nearly 100 km. Although they represent less than 5% of the tidally influenced coastline of Maine, they are widely distributed and occur in a variety of dynamic regimes and physiographic regions. Their morphology and backbarrier stratigraphy are different from better studied coastal plain systems, and provide important clues to the Holocene evolution of the Maine coast. In a study of geomorphic form and backbarrier stratigraphy, inlet processes and Holocene sea-level rise have been identified as the principal controls on coarse-grained barrier stratigraphy. Barriers in Maine are found in five distinct geomorphic forms, identified herein as: barrier spits, pocket barriers, double tombolos, cuspate barriers and looped barriers. The few long sandy beaches in southwestern Maine are mostly barrier spits. The remainder of the barrier types is composed primarily of gravel or mixed sand and gravel. The barriers protect a variety of backbarrier environments: fresh and brackish ponds, lagoons and fresh- and saltwater marshes. The barriers may or may not have inlets. Normal wave action, coarse-grain size and a deeply embayed coast result in barriers with steep, reflective profiles several meters above MHW. Occasional storm events completely wash over the barriers, building steep, lobate gravel fans along their landward margin. Few, if any, extensive storm layers are recognized as extending into the distal backbarrier environments, however. During sea-level rise and landward barrier retreat, this abrupt, storm-generated transition zone inters the backbarrier sediments. Statistical comparisons of barrier morphology, location and backbarrier environment type with backbarrier stratigraphy show that Holocene backbarrier stratigraphy is best predicted by the modern backbarrier environment type. This, in turn, is influenced most by the absence or presence, and long

  8. Barriers to lifestyle risk factor assessment and management in hypertension: a qualitative study of Australian general practitioners.

    PubMed

    Howes, F; Warnecke, E; Nelson, M

    2013-08-01

    Hypertension is a leading cause of mortality and disease burden worldwide, yet its management remains suboptimal. Identification and management of lifestyle risk factors should be a clinical priority in all patients because of the beneficial effects of lifestyle intervention on blood pressure. The objective of this qualitative focus group study was to identify barriers to lifestyle management in hypertension in Australian general practice. Purposeful sampling was used to select large group practices. Six focus groups (n=30) were audio recorded and transcribed. An iterative thematic analysis was conducted. Overall participants felt they had the required knowledge to provide broad lifestyle advice. However, cynicism dominated due to an overwhelming lack of success in practice. Patient reluctance and ambivalence were identified as major barriers but participants were willing to share the responsibility. Other barriers included time, reduced access to allied health and broader determinants of health. General practitioners need to be empowered to allow continuation of valuable lifestyle advice and counselling. The results emphasise the importance of ongoing lifestyle assessment and tailoring of management to the complex interplay of factors that impact on a patient's ability to adopt and maintain lifestyle change. System issues need to be addressed to provide better streamlined care.

  9. System and Patient Barriers to Care among People Living with HIV/AIDS in Houston/Harris County, Texas: HIV Medical Care Providers' Perspectives.

    PubMed

    Mgbere, Osaro; Khuwaja, Salma; Bell, Tanvir K; Rodriguez-Barradas, Maria C; Arafat, Raouf; Essien, Ekere James; Singh, Mamta; Aguilar, Jonathan; Roland, Eric

    2015-01-01

    In the United States, a considerable number of people diagnosed with HIV are not receiving HIV medical care due to some barriers. Using data from the Medical Monitoring Project survey of HIV medical care providers in Houston/Harris County, Texas, we assessed the HIV medical care providers' perspectives of the system and patient barriers to HIV care experienced by people living with HIV/AIDS (PLWHA). The study findings indicate that of the 14 HIV care barriers identified, only 1 system barrier and 7 patient barriers were considered of significant (P ≤ .05) importance, with the proportion of HIV medical care providers' agreement to these barriers ranging from 73.9% (cost of health care) to 100% (lack of social support systems and drug abuse problems). Providers' perception of important system and patient barriers varied significantly (P ≤ .05) by profession, race/ethnicity, and years of experience in HIV care. To improve access to and for consistent engagement in HIV care, effective intervention programs are needed to address the barriers identified especially in the context of the new health care delivery system.

  10. Advanced thermal barrier coating system development. Technical progress report, April 1, 1996--May 31, 1996

    SciTech Connect

    1996-06-10

    Objectives of this program are to provide an improved thermal barrier system with increased temperature capability and reliability relative to current systems. This report describes the bond coat development and deposition, manufacturing, and repair.

  11. Advanced thermal barrier coating system development. Technical progress report, January 1, 1996--March 31, 1996

    SciTech Connect

    1996-04-08

    Objectives of this program are to provide a thermal barrier coating system with increased temperature capability and improved reliability relative to current state of the art systems. This report describes the bond coat deposition process, manufacturing, and repair.

  12. Remedial Action Assessment System

    1997-02-01

    RAAS1.1 is a software-based system designed to assist remediation professionals at each stage of the environmental analysis process. RAAS1.1 provides a template for environmental restoration analysis, and provides the user with key results at each step in the analysis. RAAS1.1 assists the user to develop a coherent and consistent site description, estimate baseline and residual risk to public health from the contaminated site, identify applicable environmental restoration technologies, and formulate feasible remedial response alternatives. Inmore » addition, the RAAS1.1 methodology allows the user to then assess and compare those remedial response alternatives across EPA criteria, including: compliance with objectives; short-term and long-term effectiveness; extent of treatment; and implementability of the technologies. The analytic methodology is segmented and presented in a standardized, concise, easy-to-use format that can be viewed on the personal computer screen, saved and further manipulated, or printed for later use. Each screen and analytic step is accessed via a user-friendly personal computer graphical interface. Intuitively-designed buttons, menus, and lists help the user focus in on the particular information and analysis component of interest; the corresponding results are presented in a format that facilitates their use in decision-making.« less

  13. Barriers to Health Care in Rural Mozambique: A Rapid Ethnographic Assessment of Planned Mobile Health Clinics for ART

    PubMed Central

    Schwitters, Amee; Lederer, Philip; Zilversmit, Leah; Gudo, Paula Samo; Ramiro, Isaias; Cumba, Luisa; Mahagaja, Epifanio; Jobarteh, Kebba

    2015-01-01

    ABSTRACT Background: In Mozambique, 1.6 million people are living with HIV, and over 60% of the population lives in rural areas lacking access to health services. Mobile health clinics, implemented in 2013 in 2 provinces, are beginning to offer antiretroviral therapy (ART) and basic primary care services. Prior to introduction of the mobile health clinics in the communities, we performed a rapid ethnographic assessment to understand barriers to accessing HIV care and treatment services and acceptability and potential use of the mobile health clinics as an alternative means of service delivery. Methods: We conducted assessments in Gaza province in January 2013 and in Zambezia Province in April–May 2013 in districts where mobile health clinic implementation was planned. Community leaders served as key informants, and chain-referral sampling was used to recruit participants. Interviews were conducted with community leaders, health care providers, traditional healers, national health system patients, and traditional healer patients. Interviewees were asked about barriers to health services and about mobile health clinic acceptance. Results: In-depth interviews were conducted with 117 participants (Gaza province, n = 57; Zambezia Province, n = 60). Barriers to accessing health services included transportation and distance-related issues (reliability, cost, and travel time). Participants reported concurrent use of traditional and national health systems. The decision to use a particular health system depended on illness type, service distance, and lack of confidence in the national health system. Overall, participants were receptive to using mobile health clinics for their health care and ability to increase access to ART. Hesitations concerning mobile health clinics included potentially long wait times due to high patient loads. Participants emphasized the importance of regular and published visit schedules and inclusion of community members in planning mobile

  14. Theoretical domains framework to assess barriers to change for planning health care quality interventions: a systematic literature review

    PubMed Central

    Mosavianpour, Mirkaber; Sarmast, Hamideh Helen; Kissoon, Niranjan; Collet, Jean-Paul

    2016-01-01

    Background Theoretical domains framework (TDF) provides an integrative model for assessing barriers to behavioral changes in order to suggest interventions for improvement in behavior and ultimately outcomes. However, there are other tools that are used to assess barriers. Objective The objective of this study is to determine the degree of concordance between domains and constructs identified in two versions of the TDF including original (2005) and refined version (2012) and independent studies of other tools. Methods We searched six databases for articles that studied barriers to health-related behavior changes of health care professionals or the general public. We reviewed quantitative papers published in English which included their questionnaires in the article. A table including the TDF domains of both original and refined versions and related constructs was developed to serve as a reference to describe the barriers assessed in the independent studies; descriptive statistics were used to express the results. Results Out of 552 papers retrieved, 50 were eligible to review. The barrier domains explored in these articles belonged to two to eleven domains of the refined TDF. Eighteen articles (36%) used constructs outside of the refined version. The spectrum of barrier constructs of the original TDF was broader and could meet the domains studied in 48 studies (96%). Barriers in domains of “environmental context and resources”, “beliefs about consequences”, and “social influences” were the most frequently explored in 42 (84%), 37 (74%), and 33 (66%) of the 50 articles, respectively. Conclusion Both refined and original TDFs cataloged barriers measured by the other studies that did not use TDF as their framework. However, the original version of TDF explored a broader spectrum of barriers than the refined version. From this perspective, the original version of the TDF seems to be a more comprehensive tool for assessing barriers in practice. PMID:27499628

  15. Long-term hygienic barrier efficiency of a compact on-site wastewater treatment system.

    PubMed

    Heistad, Arve; Seidu, Razak; Flø, Andreas; Paruch, Adam M; Hanssen, Jon F; Stenström, ThorAxel

    2009-01-01

    The long-term use of a filter-based, on-site wastewater treatment system increases nutrient discharge to receiving waters and may reduce its hygienic barrier efficiency. The main purpose of this research was to assess the hygienic barrier efficiency and the associated health risks of an on-site system that had exceeded its 5-yr design capacity with respect to phosphorus (P) removal. The system was investigated for bacteria and virus removal and assessed with respect to potential health risks in relation to reuse of effluent for irrigation. The system consists of a septic tank, a pressure-dosed vertical flow biofilter, and an up-flow filter unit with lightweight clay aggregates. The total P concentration in the effluent had increased gradually from initially <0.1 mg P L(-1) during the first 2 yr of operation to 1.8 mg P L(-1) after 5.3 yr. Escherichia coli was used as an indicator organism for fecal bacteria removal, whereas bacteriophages phiX174 and Salmonella typhimurium phage 28B (S.t. 28B) were used to model enteric virus removal. An overall decrease in E. coli removal occurred from a complete (approximately 5.6 log10) reduction during the first 3 yr of operation to 2.6 log10 reduction. The removal amounts of the bacteriophages phiX174 and S.t. 28B were 3.9 and 3.7 log10, respectively. Based on removal of S.t. 28B, the risks of rotavirus infection and disease for the investigated scenarios were above the acceptable level of 10(-4) and 10(-3), respectively, as defined by the World Health Organization.

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

    SciTech Connect

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

    2010-08-31

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

  17. Interactions between barrier islands and backbarrier marshes affect island system response to sea level rise: Insights from a coupled model

    NASA Astrophysics Data System (ADS)

    Walters, David; Moore, Laura J.; Duran Vinent, Orencio; Fagherazzi, Sergio; Mariotti, Giulio

    2014-09-01

    Interactions between backbarrier marshes and barrier islands will likely play an important role in determining how low-lying coastal systems respond to sea level rise and changes in storminess in the future. To assess the role of couplings between marshes and barrier islands under changing conditions, we develop and apply a coupled barrier island-marsh model (GEOMBEST+) to assess the impact of overwash deposition on backbarrier marsh morphology and of marsh morphology on rates of island migration. Our model results suggest that backbarrier marsh width is in a constant state of change until either the backbarrier basin becomes completely filled or backbarrier marsh deposits have completely eroded away. Results also suggest that overwash deposition is an important source of sediment, which allows existing narrow marshes to be maintained in a long-lasting alternate state (~500 m wide in the Virginia Barrier Islands) within a range of conditions under which they would otherwise disappear. The existence of a narrow marsh state is supported by observations of backbarrier marshes along the eastern shore of Virginia. Additional results suggest that marshes reduce accommodation in the backbarrier bay, which, in turn, decreases island migration rate. As climate change results in sea level rise, and the increased potential for intense hurricanes resulting in overwash, it is likely that these couplings will become increasingly important in determining future system behavior.

  18. Breakdown of the Blood-Ocular Barrier as a Strategy for the Systemic Use of Nanosystems

    PubMed Central

    Occhiutto, Marcelo L.; Freitas, Fatima R.; Maranhao, Raul C.; Costa, Vital P.

    2012-01-01

    Several drug delivery systems have been proposed to overcome physiological barriers, improving ocular bioavailability. Systemic routes are seldom used due to the blood-ocular barrier. Novel drug delivery systems based on nanotechnology techniques have been developed to overcome ocular physiological barriers. This non-systematic review suggests the utilization of a transitory blood-ocular breakdown to allow the access of drugs by nanotechnology drug delivery systems via the systemic route. We discuss the possible ways to cause the breakdown of the blood-ocular barrier: acute inflammation caused by intraocular surgery, induced ocular hypotony, and the use of inflammatory mediators. The suitability of use of the systemic route and its toxic effects are also discussed in this article. PMID:24300231

  19. A method for risk analysis across governance systems: a Great Barrier Reef case study

    NASA Astrophysics Data System (ADS)

    Dale, Allan; Vella, Karen; Pressey, Robert L.; Brodie, Jon; Yorkston, Hugh; Potts, Ruth

    2013-03-01

    Healthy governance systems are key to delivering sound environmental management outcomes from global to local scales. There are, however, surprisingly few risk assessment methods that can pinpoint those domains and sub-domains within governance systems that are most likely to influence good environmental outcomes at any particular scale, or those if absent or dysfunctional, most likely to prevent effective environmental management. This paper proposes a new risk assessment method for analysing governance systems. This method is then tested through its preliminary application to a significant real-world context: governance as it relates to the health of Australia’s Great Barrier Reef (GBR). The GBR exists at a supra-regional scale along most of the north eastern coast of Australia. Brodie et al (2012 Mar. Pollut. Bull. 65 81-100) have recently reviewed the state and trend of the health of the GBR, finding that overall trends remain of significant concern. At the same time, official international concern over the governance of the reef has recently been signalled globally by the International Union for the Conservation of Nature (IUCN). These environmental and political contexts make the GBR an ideal candidate for use in testing and reviewing the application of improved tools for governance risk assessment.

  20. Overcoming Barriers: Adolescents’ Experiences Using a Mobile Phone Dietary Assessment App

    PubMed Central

    Svensson, Åsa; Magnusson, Maria

    2016-01-01

    Background The use of new technology has the potential to increase participation rates in dietary studies and improve the validity of collected dietary data. However, to evaluate the usability of developed dietary methods, qualitative studies of participants’ experiences and perceptions are needed. Objective To explore adolescents’ experiences using a newly developed mobile phone dietary assessment app, with a focus on factors that could affect their recording of dietary intake. Methods Focus group interviews were conducted with 75 participants who had used a newly developed mobile phone dietary assessment app in a quantitative evaluation study. The interviews were analyzed using qualitative content analysis and the theoretical framework of Self Determination Theory was applied. Results The adolescents’ use of the mobile phone dietary assessment app was characterized by their struggle to overcome several perceived barriers. Facilitators that helped adolescents complete the method were also identified. Motivation was found to be an important facilitator, and intrinsically motivated participants completed the method because they found it fun to use. The autonomous extrinsically motivated participants completed the method for the greater good, in order to contribute to the study. The controlled extrinsically motivated participants completed the method to get a reward or avoid punishment. Amotivated participants did not complete the method. More motivated participants were assumed to be more able to overcome barriers and needed less facilitators. Conclusions Future studies that examine the recording of food intake should include systematic efforts that aim to minimize identified barriers and promote identified facilitators. Further research should specifically aim at studying methods for (and effects of) increasing intrinsic motivation by supporting autonomy, competence, and relatedness among adolescents asked to participate in dietary studies. PMID:27473462

  1. Assessment of active play, inactivity and perceived barriers in an inner city neighborhood.

    PubMed

    Kottyan, Gregg; Kottyan, Leah; Edwards, Nicholas M; Unaka, Ndidi I

    2014-06-01

    Avondale, a disadvantaged neighborhood in Cincinnati, lags behind on a number of indicators of child well-being. Childhood obesity has become increasingly prevalent, as one-third of Avondale's kindergarteners are obese or overweight. The study objective was to determine perceptions of the quantity of and obstacles to childhood physical activity in the Avondale community. Caregivers of children from two elementary schools were surveyed to assess their child's physical activity and barriers to being active. Three hundred and forty surveys were returned out of 1,047 for a response rate of 32%. On school days, 41% of caregivers reported that their children spent more than 2 h watching television, playing video games, or spending time on the computer. While over half of respondents reported that their children get more than 2 h of physical activity on school days, 14% of children were reported to be physically active less than 1 h per day. Caregivers identified violence, cost of extracurricular activities, and lack of organized activities as barriers to their child's physical activity. The overwhelming majority of caregivers expressed interest in a program to make local playgrounds safer. In conclusion, children in Avondale are not participating in enough physical activity and are exposed to more screen time than is recommended by the AAP. Safety concerns were identified as a critical barrier to address in future advocacy efforts in this community. This project represents an important step toward increasing the physical activity of children in Avondale and engaging the local community.

  2. Assessment of institutional barriers to the use of natural gas fuel in automotive vehicle fleets

    NASA Technical Reports Server (NTRS)

    Jablonski, J.; Lent, L.; Lawrence, M.; White, L.

    1983-01-01

    Institutional barriers to the use of natural gas as a fuel for motor vehicle fleets were identified. Recommendations for barrier removal were developed. Eight types of institutional barriers were assessed: (1) lack of a national standard for the safe design and certification of natural gas vehicles and refueling stations; (2) excessively conservative or misapplied state and local regulations, including bridge and tunnel restrictions, restrictions on types of vehicles that may be fueled by natural gas, zoning regulations that prohibit operation of refueling stations, parking restrictions, application of LPG standards to LNG vehicles, and unintentionally unsafe vehicle or refueling station requirements; (3) need for clarification of EPA's tampering enforcement policy; (4) the U.S. hydrocarbon standard; (5) uncertainty concerning state utility commission jurisdiction; (6) sale for resale prohibitions imposed by natural gas utility companies or state utility commissions; (7) uncertainty of the effects of conversions to natural gas on vehicle manufactures warranties; and (8) need for a natural gas to gasoline equivalent units conversion factor for use in calculation of state road use taxes.

  3. Geomicrobiological Regeneration of Iron Sulfides in Engineered barrier Systems

    NASA Astrophysics Data System (ADS)

    Vannela, R.; Adriaens, P.; Hayes, K. F.

    2005-12-01

    The reactive capacity of iron sulfide-based permeable reactive barriers (PRB) to complex and co-precipitate heavy metal ions from groundwater will depend on the potential for regeneration of reactive FeS during the expected lifetime of the PRB. FeS reactivity may decrease in a PRB in time as the result of the following processes: (i) oxidation of FeS and the formation of ferric iron (Fe(III)) oxide solids in the presence of oxygenated groundwater at the entrance of the PRB, (ii) oxidation of FeS in the presence of redox active metals like As(V) with the formation of ferric solids, (iii) co-precipitation of heavy metals within the PRB with the reactive FeS leading to the formation of insoluble metal sulfides co-precipitates with the concomitant release of ferrous iron and formation of ferrous (Fe(II) oxide, hydroxide, or carbonate solids, (iv) clogging of the PRB structure due to formation of precipitate products from processes (i) - (iii).. We have demonstrated the formation of triolite in the presence of an oxidized form of hydrous ferric oxide (HFO), various sulfate concentrations, and biomass densities for the sulfate reducing bacterium (SRB) Desulfovibrio vulgaris. This result has allowed us to demonstrate the feasibility of regeneration of FeS from the ferric oxide and hydroxide solids that may be produced under scenarios (i) and (ii) above as well as to establish the electron donor and acceptor requirements for this SRB. Using Desulfobacterium autotrophicum, both HFO and soluble complexed forms of ferric iron gave rise to the formation of mackinawite. The latter have been shown to react with As (V) and Cd (II) to form ferric solids. Both organisms will be used to generate FeS solids in the presence of crystalline forms of ferric solids expected to form from scenarios (i) and (ii) (e.g., goethite and the mixed Fe(II)/(Fe(III) magnetite, and green rusts) and ferrous iron solids from scenarios (iii) and (iv) (Fe(II) oxides and siderite). Similar to the study

  4. The advantages and barriers in the implementation of a substance dependence treatment information system (SDTIS).

    PubMed

    Ajami, Sima; Mellat-Karkevandi, Zahra

    2015-11-01

    Addiction is a phenomenon that causes structural changes in different systems of society. Studies show for planning of addiction prevention and treatment, it is necessary to create an information management system. Substance dependence information systems refer to systems which collect, analyse and report data related to substance dependence information. The aim of this study was to identify advantages and barriers to implement Substance Dependence Treatment Information System (SDTIS). This study was a narrative review. Our review divided into three phases: literature collection, assessing, and selection. We employed the following keywords and their combinations in different areas of articles. In this study, 22 of collected articles and reports were selected based on their relevancy. We found many advantages for a substance dependence treatment information system such as recording sufficient, complete and accurate information and easy and timely access to them and monitoring and enhancing the quality of care received by patients. But we may face some concerns for implementing this information system like taking time and funds from client services, being expensive or even problems regarding the quality of data contained in these information systems. There are some important problems in the way of implementing. In order to overcome these issues, we need to raise community awareness.

  5. The advantages and barriers in the implementation of a substance dependence treatment information system (SDTIS).

    PubMed

    Ajami, Sima; Mellat-Karkevandi, Zahra

    2015-11-01

    Addiction is a phenomenon that causes structural changes in different systems of society. Studies show for planning of addiction prevention and treatment, it is necessary to create an information management system. Substance dependence information systems refer to systems which collect, analyse and report data related to substance dependence information. The aim of this study was to identify advantages and barriers to implement Substance Dependence Treatment Information System (SDTIS). This study was a narrative review. Our review divided into three phases: literature collection, assessing, and selection. We employed the following keywords and their combinations in different areas of articles. In this study, 22 of collected articles and reports were selected based on their relevancy. We found many advantages for a substance dependence treatment information system such as recording sufficient, complete and accurate information and easy and timely access to them and monitoring and enhancing the quality of care received by patients. But we may face some concerns for implementing this information system like taking time and funds from client services, being expensive or even problems regarding the quality of data contained in these information systems. There are some important problems in the way of implementing. In order to overcome these issues, we need to raise community awareness. PMID:26941816

  6. The advantages and barriers in the implementation of a substance dependence treatment information system (SDTIS)

    PubMed Central

    Ajami, Sima; Mellat-Karkevandi, Zahra

    2015-01-01

    Addiction is a phenomenon that causes structural changes in different systems of society. Studies show for planning of addiction prevention and treatment, it is necessary to create an information management system. Substance dependence information systems refer to systems which collect, analyse and report data related to substance dependence information. The aim of this study was to identify advantages and barriers to implement Substance Dependence Treatment Information System (SDTIS). This study was a narrative review. Our review divided into three phases: literature collection, assessing, and selection. We employed the following keywords and their combinations in different areas of articles. In this study, 22 of collected articles and reports were selected based on their relevancy. We found many advantages for a substance dependence treatment information system such as recording sufficient, complete and accurate information and easy and timely access to them and monitoring and enhancing the quality of care received by patients. But we may face some concerns for implementing this information system like taking time and funds from client services, being expensive or even problems regarding the quality of data contained in these information systems. There are some important problems in the way of implementing. In order to overcome these issues, we need to raise community awareness. PMID:26941816

  7. Evaluation of the Lifetime and Thermal Conductivity of Dysprosia-Stabilized Thermal Barrier Coating Systems

    NASA Astrophysics Data System (ADS)

    Curry, Nicholas; Markocsan, Nicolaie; Östergren, Lars; Li, Xin-Hai; Dorfman, Mitch

    2013-08-01

    The aim of this study was the further development of dysprosia-stabilized zirconia coatings for gas turbine applications. The target for these coatings was a longer lifetime and higher insulating performance compared to today's industrial standard thermal barrier coating. Two morphologies of ceramic top coat were studied: one using a dual-layer system and the second using a polymer to generate porosity. Evaluations were carried out using a laser flash technique to measure thermal properties. Lifetime testing was conducted using thermo-cyclic fatigue testing. Microstructure was assessed with SEM and Image analysis was used to characterize porosity content. The results show that coatings with an engineered microstructure give performance twice that of the present reference coating.

  8. A bioindicator system for water quality on inshore coral reefs of the Great Barrier Reef.

    PubMed

    Fabricius, Katharina E; Cooper, Timothy F; Humphrey, Craig; Uthicke, Sven; De'ath, Glenn; Davidson, Johnston; LeGrand, Hélène; Thompson, Angus; Schaffelke, Britta

    2012-01-01

    Responses of bioindicator candidates for water quality were quantified in two studies on inshore coral reefs of the Great Barrier Reef (GBR). In Study 1, 33 of the 38 investigated candidate indicators (including coral physiology, benthos composition, coral recruitment, macrobioeroder densities and FORAM index) showed significant relationships with a composite index of 13 water quality variables. These relationships were confirmed in Study 2 along four other water quality gradients (turbidity and chlorophyll). Changes in water quality led to multi-faceted shifts from phototrophic to heterotrophic benthic communities, and from diverse coral dominated communities to low-diversity communities dominated by macroalgae. Turbidity was the best predictor of biota; hence turbidity measurements remain essential to directly monitor water quality on the GBR, potentially complemented by our final calibrated 12 bioindicators. In combination, this bioindicator system may be used to assess changes in water quality, especially where direct water quality data are unavailable.

  9. Chasing boundaries and cascade effects in a coupled barrier - marshes - lagoon system

    NASA Astrophysics Data System (ADS)

    Lorenzo Trueba, J.; Mariotti, G.

    2015-12-01

    Low-lying coasts are often characterized by barriers islands, shore-parallel stretches of sand separated from the mainland by marshes and lagoons. We built an exploratory numerical model to examine the morphological feedbacks within an idealized barrier - marshes -lagoon system and predict its evolution under projected rates of sea level rise and sediment supply to the backbarrier environment. Our starting point is a recently developed morphodynamic model, which couples shoreface evolution and overwash processes in a dynamic framework. As such, the model is able to capture dynamics not reproduced by morphokinematic models, which advect geometries without specific concern to processes. These dynamics include periodic barrier retreat due to time lags in the shoreface response to barrier overwash, height drowning due to insufficient overwash fluxes as sea level rises, and width drowning, which occurs when the shoreface response rate is insufficient to maintain the barrier geometry during overwash-driven landward migration. We extended the model by coupling the barrier model with a model for the evolution of the marsh platform and the boundary between the marsh and the adjacent lagoon. The coupled model explicitly describes marsh edge processes and accounts for the modification of the wave regime associated with lagoon width (fetch). Model results demonstrate that changes in factors that are not typically associated with the dynamics of coastal barriers, such as the lagoon width and the rate of export/import of sediments from and to the lagoon, can lead to previously unidentified complex responses of the coupled system. In particular, a wider lagoon in the backbarrier, and/or a reduction in the supply of muddy sediments to the backbarrier, can increase barrier retreat rates and even trigger barrier drowning. Overall, our findings highlight the importance of incorporating backbarrier dynamics in models that aim at predicting the response of barrier systems.

  10. Examining the Uptake of Central Nervous System Drugs and Candidates across the Blood-Brain Barrier.

    PubMed

    Summerfield, Scott G; Zhang, Yanyan; Liu, Houfu

    2016-08-01

    Assessing the equilibration of the unbound drug concentrations across the blood-brain barrier (Kp,uu) has progressively replaced the partition coefficient based on the ratio of the total concentration in brain tissue to blood (Kp). Here, in vivo brain distribution studies were performed on a set of central nervous system (CNS)-targeted compounds in both rats and P-glycoprotein (P-gp) genetic knockout mice. Several CNS drugs are characterized by Kp,uu values greater than unity, inferring facilitated uptake across the rodent blood-brain barrier (BBB). Examples are shown in which Kp,uu also increases above unity on knockout of P-gp, highlighting the composite nature of this parameter with respect to facilitated BBB uptake, efflux, and passive diffusion. Several molecules with high Kp,uu values share common structural elements, whereas uptake across the BBB appears more prevalent in the CNS-targeted drug set than the chemical templates being generated within the current lead optimization paradigm. Challenges for identifying high Kp,uu compounds are discussed in the context of acute versus steady-state data and cross-species differences. Evidently, there is a need for better predictive models of human brain Kp,uu. PMID:27194478

  11. Examining the Uptake of Central Nervous System Drugs and Candidates across the Blood-Brain Barrier.

    PubMed

    Summerfield, Scott G; Zhang, Yanyan; Liu, Houfu

    2016-08-01

    Assessing the equilibration of the unbound drug concentrations across the blood-brain barrier (Kp,uu) has progressively replaced the partition coefficient based on the ratio of the total concentration in brain tissue to blood (Kp). Here, in vivo brain distribution studies were performed on a set of central nervous system (CNS)-targeted compounds in both rats and P-glycoprotein (P-gp) genetic knockout mice. Several CNS drugs are characterized by Kp,uu values greater than unity, inferring facilitated uptake across the rodent blood-brain barrier (BBB). Examples are shown in which Kp,uu also increases above unity on knockout of P-gp, highlighting the composite nature of this parameter with respect to facilitated BBB uptake, efflux, and passive diffusion. Several molecules with high Kp,uu values share common structural elements, whereas uptake across the BBB appears more prevalent in the CNS-targeted drug set than the chemical templates being generated within the current lead optimization paradigm. Challenges for identifying high Kp,uu compounds are discussed in the context of acute versus steady-state data and cross-species differences. Evidently, there is a need for better predictive models of human brain Kp,uu.

  12. Advanced thermal barrier coating system development. Technical progress report, September 1, 1996--November 30, 1996

    SciTech Connect

    1996-12-11

    Objectives of this program are to provide an improved thermal barrier coating system with improved temperature capability and reliability. This report describes the bond/coating process and manufacturing.

  13. Advanced thermal barrier coating system development. Technical progress report, June 1, 1997--August 31, 1997

    SciTech Connect

    1997-09-12

    Objectives of this program are to provide an advanced thermal barrier coating system with improved reliability and temperature capabilities. This report describes the manufacturing, deposition, bonding, non-destructive analysis; maintenance, and repair.

  14. Advanced thermal barrier coating system development. Technical progress report, March 1, 1997--May 31, 1997

    SciTech Connect

    1997-06-13

    Objectives of this program are to provide an improved thermal barrier coating system with improved reliability and temperature capability. This report describes progress in manufacturing, bonding, deposition, non-destructive evaluation, repair, and maintenance.

  15. Software Tools for Lifetime Assessment of Thermal Barrier Coatings Part II — Bond Coat Aluminum Depletion Failure

    NASA Astrophysics Data System (ADS)

    Renusch, Daniel; Rudolphi, Mario; Schütze, Michael

    The use of thermal barrier coatings (TBCs) made from yttria stabilized zirconia (YSZ) on superalloy base materials has been a significant step to a new level of operational limits in high temperature applications. By the application of a TBC in conjunction with cooling of the component material the operating temperature can be raised and higher efficiencies are achieved. As a consequence of the raised temperature failure of a TBC leads to an increased oxidative attack of the underlying bond coat material and therefore needs to be avoided. The lifetime prediction of thermal barrier coatings is therefore of interest to ensure safe operation within the inspection intervals. Several mechanisms have been identified to play a critical role in the degradation of TBC systems. Here we discuss failure of TBC systems due to bond coat aluminum depletion. This type of chemical failure may occur when the bond coat material is critically depleted of aluminum and instead of a dense slow growing α-alumina the formation of voluminous and fast growing spinels is promoted. Lifetime prediction for this failure mode requires a fundamental understanding of diffusion mechanisms and in particular the interaction of different diffusion rates in the bond coat and substrate material. Aim of this work was therefore to develop software tools that allow user friendly analysis of measured Al profiles for the assessment of diffusion rates and consequently for lifetime prediction.

  16. Condition Assessment Information System

    2002-09-16

    CAIS2000 records, tracks and cost maintenance deficiencies associated with condition assessments of real property assets. Cost information is available for 39,000 items in the currenht RS Means, Facilities Construction Manual. These costs can, in turn, be rolled by by asset to produce the summary condition of an asset or site.

  17. Long-Term Climate Change Assessment Task for the Hanford Site Permanent Isolation Barrier Development Program: Status through FY 1992

    SciTech Connect

    Petersen, K.L.; Chatters, J.C.

    1993-07-01

    The Hanford Site Permanent Isolation Barrier Development Program (Barrier Development Program) was organized (Adams and Wing 1986) to develop the technology needed to provide an in-place disposal capability for the US Department of Energy at the Hanford Site in southeastern Washington. The goals of the Barrier Development Program are to provide defensible evidence that final barrier design(s) will adequately control water infiltration, plant and animal intrusion, and wind and water erosion for a minimum of 1,000 years; to isolate wastes from the accessible environment; and to use markers to warn inadvertent human intruders. Evidence for barrier performance will be obtained by conducting laboratory experiments, field tests, computer modeling, and other studies that establish confidence in the barrier`s ability to meet its 1,000-year design life. The performance and stability of natural barrier analogs that have existed for several millennia and the reconstruction of climate changes during the past 10,000 to 125,000 years also will provide insight into bounding conditions of possible future changes and increase confidence in the barriers design. In the following discussion the term {open_quotes}long-term{close_quotes} references periods of time up to 1000`s of years, distinguishing it from {open_quotes}short-term{close_quotes} weather patterns covering a decade or less. Specific activities focus on planning and conducting a series of studies and tests required to confirm key aspects of the barrier design. The effort is a collaborative one between scientists and engineers from Westinghouse Hanford Company (Westinghouse Hanford) and Pacific Northwest Laboratory (PNL) to design barriers to limit movement of radionuclides and other contaminants to the accessible environment for at least 1,000 years. These activities have been divided into 14 groups of tasks that aid in the complete development of protective barrier and warning marker system.

  18. Access to the US Department of Veterans Affairs health system: self-reported barriers to care among returnees of Operations Enduring Freedom and Iraqi Freedom

    PubMed Central

    2013-01-01

    Background The U.S. Department of Veterans Affairs (VA) implemented the Polytrauma System of Care to meet the health care needs of military and veterans with multiple injuries returning from combat operations in Afghanistan and Iraq. Studies are needed to systematically assess barriers to use of comprehensive and exclusive VA healthcare services from the perspective of veterans with polytrauma and with other complex health outcomes following their service in Afghanistan and Iraq. These perspectives can inform policy with regard to the optimal delivery of care to returning veterans. Methods We studied combat veterans (n = 359) from two polytrauma rehabilitation centers using structured clinical interviews and qualitative open-ended questions, augmented with data collected from electronic health records. Our outcomes included several measures of exclusive utilization of VA care with our primary exposure as reported access barriers to care. Results Nearly two thirds of the veterans reported one or more barriers to their exclusive use of VA healthcare services. These barriers predicted differences in exclusive use of VA healthcare services. Experiencing any barriers doubled the returnees’ odds of not using VA exclusively, the geographic distance to VA barrier resulted in a 7 fold increase in the returnees odds of not using VA, and reporting a wait time barrier doubled the returnee’s odds of not using VA. There were no striking differences in access barriers for veterans with polytrauma compared to other returning veterans, suggesting the barriers may be uniform barriers that predict differences in using the VA exclusively for health care. Conclusions This study provides an initial description of utilization of VA polytrauma rehabilitation and other medical care for veteran returnees from all military services who were involved in combat operations in Afghanistan or Iraq. Our findings indicate that these veterans reported important stigmatization and barriers to

  19. Assessment of fluctuating decision-making capacity in individuals with communication barriers: a case study.

    PubMed

    Pachet, Arlin; Allan, Lauren; Erskine, Leslie

    2012-01-01

    A current need exists for research to assist clinicians in the capacity evaluation process, especially in relation to assessment of clients with complex issues such as fluctuating capacity and communication barriers. The aim of this article is to promote knowledge and consideration of these issues through an examination of neuropsychological, ethical, and medical-legal factors associated with the assessment of capacity in an individual with both fluctuating capacity and communication impairments. The discussion includes a narrative case study of a complex individual case seen by the Regional Capacity Assessment Team (RCAT) for an assessment of decision-making capacity related to personal and financial matters. Relevant background information about this client, behavioral observations, neuropsychological test results, and the process and outcome of the RCAT targeted capacity interview are presented. Based on previous literature and the case study, a series of recommendations are provided to guide the clinician through the capacity evaluation process with individuals with complex issues. Common pitfalls, nuances, and dilemmas involved in capacity assessment are addressed.

  20. Multi-phase functionally graded materials for thermal barrier systems

    SciTech Connect

    Jackson, M.R.; Ritter, A.M.; Gigliotti, M.F.; Kaya, A.C.; Gallo, J.P.

    1996-12-31

    Jet engine and gas turbine hot section components can be protected from the 1,350--1,650 C combustion gases by thermal barrier coatings (TBCs). Metallic candidates for functionally graded material (FGM) coatings have been evaluated for potential use in bonding zirconia to a single crystal superalloy. Properties for four materials were studied for the low-expansion layer adjacent to the ceramic. Ingots were produced for these materials, and oxidation, expansion and modulus were determined. A finite element model was used to study effects of varying the FGM layers. Elastic modulus dominated stress generation, and a 20--25% reduction in thermal stress generated within the zirconia layer may be possible.

  1. Understanding barriers to evidence-based assessment: clinician attitudes toward standardized assessment tools.

    PubMed

    Jensen-Doss, Amanda; Hawley, Kristin M

    2010-01-01

    In an era of evidence-based practice, why are clinicians not typically engaged in evidence-based assessment? To begin to understand this issue, a national multidisciplinary survey was conducted to examine clinician attitudes toward standardized assessment tools. There were 1,442 child clinicians who provided opinions about the psychometric qualities of these tools, their benefit over clinical judgment alone, and their practicality. Doctoral-level clinicians and psychologists expressed more positive ratings in all three domains than master's-level clinicians and nonpsychologists, respectively, although only the disciplinary differences remained significant when predictors were examined simultaneously. All three attitude scales were predictive of standardized assessment tool use, although practical concerns were the strongest and only independent predictor of use.

  2. Substitutes for Career Mentoring: Promoting Equal Opportunity through Career Management and Assessment Systems.

    ERIC Educational Resources Information Center

    Dreher, George P.; Dougherty, Thomas W.

    1997-01-01

    Women and nonwhite men may be able to overcome career barriers posed by lack of mentors through organizational career management and assessment systems (CMAS). CMAS could fulfill such mentoring functions as sponsorship, visibility, coaching, protection, and challenge. (SK)

  3. Reactive barrier system for nitrate removal from mine effluents in northern Sweden: Laboratory experiments

    NASA Astrophysics Data System (ADS)

    Herbert, Roger

    2010-05-01

    Laboratory column experiments have been conducted to determine nitrate removal rates from mine effluents by denitrification, with the purpose of providing initial data for the construction of a pilot scale reactive barrier system at the Malmberget iron mine, Sweden. Experiments were conducted at several different flow rates at 5C, 10C and room temperature; annual mean temperatures at the Malmberget site lie close to 0C. Columns were filled with an organic substrate consisting of sawdust mixed with sewage sludge, the source of denitrifying bacteria, supported by oven-dried clay pellets. Apparent denitrification rates, calculated from inflow and outflow nitrate concentrations and column hydraulic residence time, ranged from 5 to 13 mg N/L/d, with the lowest rates corresponding to the 5C experiments. These rates are, however, limited to a certain degree by the low flow rate and the supply of electrons acceptors (i.e. nitrate) to denitrifying bacteria. Results from the column experiment have been used to construct a barrier system in Malmberget, Sweden. Trial runs with the pilot-scale barrier will be conducted during 2010, with the purpose of determining the performance of the barrier as mean air temperatures increase from below to above 0C and saturated flow commences in the barrier. The barrier system is constructed as a rectangular container with steel sheet walls (9m length in flow direction, 1.5m deep), and the flow rate will be adjusted to a hydraulic residence time of 1 day. The pilot-scale barrier system currently lies above ground, but a permanent barrier system would be installed below the ground surface so that the system can be maintained at positive temperatures throughout the year.

  4. Assessment of active play, inactivity and perceived barriers in an inner city neighborhood

    PubMed Central

    Kottyan, Gregg; Kottyan, Leah; Edwards, Nicholas M.; Unaka, Ndidi I.

    2014-01-01

    Avondale, a disadvantaged neighborhood in Cincinnati, lags behind on a number of indicators of child well-being. Childhood obesity has become increasingly prevalent, as one third of Avondale’s kindergarteners are obese or overweight. The study objective was to determine perceptions of the quantity of and obstacles to childhood physical activity in the Avondale community. Caregivers of children from two elementary schools were surveyed to assess their child’s physical activity and barriers to being active. Three hundred forty surveys were returned out of 1,047 for a response rate of 32%. On school days, 41% of caregivers reported that their children spent more than 2 hours watching television, playing video games, or spending time on the computer. While over half of respondents reported that their children get more than 2 hours of physical activity on school days, 14% of children were reported to be physically active less than 1 hour per day. Caregivers identified violence, cost of extracurricular activities, and lack of organized activities as barriers to their child’s physical activity. The overwhelming majority of caregivers expressed interest in a program to make local playgrounds safer. In conclusion, children in Avondale are not participating in enough physical activity and are exposed to more screen time than is recommended by the AAP. Safety concerns were identified as a critical barrier to address in future advocacy efforts in this community. This project represents an important step toward increasing the physical activity of children in Avondale and engaging the local community. PMID:24306236

  5. Sub-barrier fusion excitation for the system {sup 7}Li + {sup 28}Si

    SciTech Connect

    Sinha, Mandira; Majumdar, H.; Basu, P.; Roy, Subinit; Biswas, M.; Pradhan, M. K.; Kailas, S.

    2008-08-15

    The sub-barrier fusion excitation functions are measured for the first time for the system {sup 7}Li+ {sup 28}Si by the characteristic {gamma}-ray method in the energy range E{sub lab}=7-11.5 MeV. The results show an enhancement, below the barrier, by about a factor of two when compared with the one-dimensional barrier penetration (1D BPM) model. Introduction of coupling with the rotational 2{sup +} state (1.779 MeV) of the target improves the fit somewhat, but still an enhancement of about 25-40% remains.

  6. Response of a thermal barrier system to acoustic excitation in a gas turbine nuclear reactor

    SciTech Connect

    Betts, W.S. Jr.; Blevins, R.D.

    1980-11-01

    A gas turbine located within a High-Temperature Gas-Cooled Reactor (HTGR) induces high acoustic sound pressure levels into the primary coolant (helium). This acoustic loading induces high cycle fatigue stresses which may control the design of the thermal barrier system. This study examines the dynamic response of a thermal barrier configuration consisting of a fibrous insulation compressed against the reactor vessel by a coverplate which is held in position by a central attachment fixture. The results of dynamic vibration analyses indicate the effect of the plate size and curvature and the attachment size on the response of the thermal barrier.

  7. Video systems for alarm assessment

    SciTech Connect

    Greenwoll, D.A.; Matter, J.C. ); Ebel, P.E. )

    1991-09-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing closed-circuit television systems for video alarm assessment. There is a section on each of the major components in a video system: camera, lens, lighting, transmission, synchronization, switcher, monitor, and recorder. Each section includes information on component selection, procurement, installation, test, and maintenance. Considerations for system integration of the components are contained in each section. System emphasis is focused on perimeter intrusion detection and assessment systems. A glossary of video terms is included. 13 figs., 9 tabs.

  8. Health impact assessment: assessing opportunities and barriers to intersectoral health improvement in an expanded European Union

    PubMed Central

    Lock, K.; McKee, M.

    2005-01-01

    On 1 May 2004 the European Union (EU) underwent unprecedented enlargement, from 15 to 25 countries, increasing its population by 20% to over 450 million. Although EU law has limited specific competence in the area of health, its influence on other policy sectors such as agriculture, trade, and employment has wide ranging implications for health. Yet with the exception of provisions on communicable disease control and food safety, public health considerations have played little part in negotiations on EU accession. This paper argues for an intersectoral public health approach in the expanded EU. It reviews the legal basis for assessing the health impacts of policy in the EU and, using health impact assessment as a case study, it examines how well the new member states may be prepared to tackle intersectoral public health action within the constraints imposed by EU policy. PMID:15831682

  9. Perceptions of physicians about knowledge sharing barriers in Turkish health care system.

    PubMed

    Gider, Ömer; Ocak, Saffet; Top, Mehmet

    2015-05-01

    This study was based on knowledge sharing barriers about attitudes of physicians in Turkish health care system. The present study aims to determine whether the knowledge sharing barriers about attitudes of physicians vary depending on gender, position, departments at hospitals, and hospital ownership status. This study was planned and conducted on physicians at one public hospital, one university hospital, and one private hospital in Turkey. 209 physicians were reached for data collection. The study was conducted in June-September 2014. The questionnaire (developed by A. Riege, (J. Knowl. Manag. 9(3):18-35, 2005)), five point Likert-type scale including 39 items having the potential of the physicians' knowledge- sharing attitudes and behaviors, was used in the study for data collection. Descriptive statistics, reliability analysis, student t test and ANOVA were used for data analysis. According to results of this study, there was medium level of knowledge sharing barriers within hospitals. In general, physicians had perceptions about the lowest level individual barriers, intermediate level organizational barriers and the highest level technological barriers perceptions, respectively. This study revealed that some knowledge sharing barriers about attitudes of physicians were significantly difference according to hospital ownership status, gender, position and departments. Most evidence medical decisions and evidence based practice depend on experience and knowledge of existing options and knowledge sharing in health care organizations. Physicians are knowledge and information-intensive and principal professional group in health care context.

  10. Quantitative assessment of the surface crack density in thermal barrier coatings

    NASA Astrophysics Data System (ADS)

    Yang, Li; Zhong, Zhi-Chun; Zhou, Yi-Chun; Lu, Chun-Sheng

    2014-04-01

    In this paper, a modified shear-lag model is developed to calculate the surface crack density in thermal barrier coatings (TBCs). The mechanical properties of TBCs are also measured to quantitatively assess their surface crack density. Acoustic emission (AE) and digital image correlation methods are applied to monitor the surface cracking in TBCs under tensile loading. The results show that the calculated surface crack density from the modified model is in agreement with that obtained from experiments. The surface cracking process of TBCs can be discriminated by their AE characteristics and strain evolution. Based on the correlation of energy released from cracking and its corresponding AE signals, a linear relationship is built up between the surface crack density and AE parameters, with the slope being dependent on the mechanical properties of TBCs. [Figure not available: see fulltext.

  11. Assessment of the effectiveness of glove use as a barrier technique in the dental operatory.

    PubMed

    Gonzalez, E; Naleway, C

    1988-09-01

    To assess the effectiveness of routine glove use as a barrier technique in the dental operatory, the relationship between frequency of glove use and hepatitis B infection was examined. Hepatitis B screening results and information on infection control practices of 1,109 dentists who attended the 1985 annual session were compiled and statistically analyzed. The results showed that 18% of the dentists wore gloves routinely, 65% wore gloves intermittently, and 17% never wore gloves. Frequency of glove use was related to hepatitis B infection (P less than .01), with dentists who never wore gloves being infected more than twice as often as dentists who wore gloves routinely. Dentists with less frequent glove use and more years in practice had a higher incidence of hepatitis B infection (P less than .0001).

  12. Noncontacting Laser Inspection System for Dimensional Profiling of Space Application Thermal Barriers

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.

    2011-01-01

    A noncontacting, two-dimensional (2-D) laser inspection system has been designed and implemented to dimensionally profile thermal barriers being developed for space vehicle applications. In a vehicle as-installed state, thermal barriers are commonly compressed between load sensitive thermal protection system (TPS) panels to prevent hot gas ingestion through the panel interface during flight. Loads required to compress the thermal barriers are functions of their construction, as well as their dimensional characteristics relative to the gaps in which they are installed. Excessive loads during a mission could damage surrounding TPS panels and have catastrophic consequences. As such, accurate dimensional profiling of thermal barriers prior to use is important. Due to the compliant nature of the thermal barriers, traditional contact measurement techniques (e.g., calipers and micrometers) are subjective and introduce significant error and variability into collected dimensional data. Implementation of a laser inspection system significantly enhanced the method by which thermal barriers are dimensionally profiled, and improved the accuracy and repeatability of collected data. A statistical design of experiments study comparing laser inspection and manual caliper measurement techniques verified these findings.

  13. Blood-nerve barrier in IgM paraproteinemic neuropathy: a clinicopathologic assessment.

    PubMed

    Kanda, T; Usui, S; Beppu, H; Miyamoto, K; Yamawaki, M; Oda, M

    1998-02-01

    We report the pathologic findings in a patient with sensorimotor neuropathy associated with Waldenström's macroglobulinemia, particularly in relation to blood-nerve barrier defects. The monoclonal IgM was of kappa type and possessed anti-HNK-1 activity. A sural nerve biopsy specimen revealed severe loss of myelinated and unmyelinated nerve fibers and gaps between adjacent endothelial cells of small endoneurial vessels. Postmortem findings 3 years later included severe loss of myelinated nerve fibers and diffuse infiltration by lymphoplasmacytic B cells throughout the peripheral nervous system, sparing the central nervous system. Findings in this case suggest an immune attack against endoneurial endothelial cells with permeation of IgM into peripheral nerve tissue. PMID:9498055

  14. Experimental and Theoretical Assessment of the Lifetime of a Gaseous-Reduced Vadose Zone Permeable Reactive Barrier

    SciTech Connect

    Thornton, Edward C.; Zhong, Lirong; Oostrom, Mart; Deng, Baolin

    2007-11-20

    The feasibility of using gaseous reduction to establish a vadose zone permeable reactive barrier was evaluated through a combination of laboratory testing activities and consideration of fundamental vadose zone transport concepts. For the experimental evaluation, a series of laboratory column tests were conducted in which sediment was first treated with diluted hydrogen sulfide. Water containing dissolved oxygen was then pumped through the columns at different flow rates to determine the reoxidation rate and the reductive capacity of the treated sediment. The results indicated that the treated sediment has a significant reductive capacity consistent with the basic reactions associated with the treatment and reoxidation processes. The observed reductive capacity was found to be dependent on the flow rate of water during the reoxidation phase of the tests. At lower flow rates, the reductive capacity approached the maximum value predicted on the basis of the treatment reaction. Thus, laboratory treatment tests should reliably predict the reductive capacity of the barrier under field conditions. A theoretical approach was undertaken to estimate the lifetime of the vadose zone barrier. An initial model assumed that the barrier lifetime is determined by the reoxidation of the barrier owing to the transport of oxygen through a vadose zone interval in which all sediment is unsaturated. The results of this evaluation suggest that barrier reoxidation is primarily related to diffusion of oxygen through the gas-filled portion of the sediment pore space. If so, the barrier lifetime could be fairly short (several years). However, the presence of finer grained strata with higher moisture content could potentially increase the barrier lifetime to 100 years or more owing to a decrease in the effective diffusion coefficient for oxygen. Thus, detailed stratagraphic characterization and modeling is needed to provide an accurate assessment of barrier lifetime at specific sites.

  15. Effect of vadose zone on the steady-state leakage rates from landfill barrier systems

    SciTech Connect

    Celik, B. Rowe, R.K. Unlue, K.

    2009-01-15

    Leakage rates are evaluated for a landfill barrier system having a compacted clay liner (CCL) underlain by a vadose zone of variable thickness. A numerical unsaturated flow model SEEP/W is used to simulate the moisture flow regime and steady-state leakage rates for the cases of unsaturated zones with different soil types and thicknesses. The results of the simulations demonstrate that harmonic mean hydraulic conductivity of coarse textured vadose zones is 3-4 orders of magnitude less than saturated hydraulic conductivity; whereas, the difference is only one order of magnitude for fine textured vadose zones. For both coarse and fine textured vadose zones, the effective hydraulic conductivity of the barrier system and the leakage rate to an underlying aquifer increases with increasing thickness of the vadose zone and ultimately reaches an asymptotic value for a coarse textured vadose zone thickness of about 10 m and a fine textured vadose zone thickness of about 5 m. Therefore, the fine and coarse textured vadose zones thicker than about 5 m and 10 m, respectively, act as an effective part of the barrier systems examined. Although the thickness of vadose zone affects the effective hydraulic conductivity of the overall barrier system, the results demonstrated that the hydraulic conductivity of the CCL is the dominant factor controlling the steady-state leakage rates through barrier systems having single low permeability clay layers.

  16. Cyclic Failure Mechanisms of Thermal and Environmental Barrier Coating Systems Under Thermal Gradient Test Conditions

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Plasma-sprayed ZrO2-8wt%Y2O3 and mullite+BSAS/Si multilayer thermal and environmental barrier coating (TBC-EBC) systems on SiC/SiC ceramic matrix composite (CMC) substrates were thermally cyclic tested under high thermal gradients using a laser high-heat-flux rig in conjunction with furnace exposure in water-vapor environments. Coating sintering and interface damage were assessed by monitoring the real-time thermal conductivity changes during the laser heat-flux tests and by examining the microstructural changes after exposure. Sintering kinetics of the coating systems were also independently characterized using a dilatometer. It was found that the coating failure involved both the time-temperature dependent sintering and the cycle frequency dependent cyclic fatigue processes. The water vapor environments not only facilitated the initial coating conductivity increases due to enhanced sintering and interface reaction, but also promoted later conductivity reductions due to the accelerated coating cracking and delamination. The failure mechanisms of the coating systems are also discussed based on the cyclic test results and are correlated to the sintering and thermal stress behavior under the thermal gradient test conditions.

  17. The Development of HfO2-Rare Earth Based Oxide Materials and Barrier Coatings for Thermal Protection Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Harder, Bryan James

    2014-01-01

    Advanced hafnia-rare earth oxides, rare earth aluminates and silicates have been developed for thermal environmental barrier systems for aerospace propulsion engine and thermal protection applications. The high temperature stability, low thermal conductivity, excellent oxidation resistance and mechanical properties of these oxide material systems make them attractive and potentially viable for thermal protection systems. This paper will focus on the development of the high performance and high temperature capable ZrO2HfO2-rare earth based alloy and compound oxide materials, processed as protective coating systems using state-or-the-art processing techniques. The emphasis has been in particular placed on assessing their temperature capability, stability and suitability for advanced space vehicle entry thermal protection systems. Fundamental thermophysical and thermomechanical properties of the material systems have been investigated at high temperatures. Laser high-heat-flux testing has also been developed to validate the material systems, and demonstrating durability under space entry high heat flux conditions.

  18. Building a dedicated information barrier system for warhead and sensitive item verification

    SciTech Connect

    ZUHOSKI,P.B.; INDUSI,J.P.; VANIER,P.E.

    1999-07-25

    This paper documents the development of a dedicated information barrier system for warhead and sensitive item verification. The system the authors describe includes software and hardware information barriers used in conjunction with suitable procedures (or protocols) to achieve a high quality verification while minimizing intrusiveness and preventing transfer of sensitive data to inspectors. The system they describe has been referred to as CIVET--Controlled Intrusiveness Verification Technology and has been implemented to verify warheads and warhead components during various exercises and demonstrations under the auspices of the Department of Energy (DOE) and the Department of Defense (DOD).

  19. Near-barrier fusion of proton- and neutron-halo systems

    NASA Astrophysics Data System (ADS)

    Aguilera, E. F.

    2016-07-01

    It is shown that the behaviour of the fusion excitation functions for proton-halo and neutron-halo systems presents important differences, especially in the energy region slightly above the barrier. Measurements for 6He, 11Li and 11Be projectiles are discussed to exemplify the behaviour of neutron-halo systems, while experiments with 8B beams illustrate the situation for proton-halo nuclei. With respect to a standard benchmark, neutron- (proton-) halo systems show a fusion suppression (enhancement) above the barrier.

  20. Sub-barrier fusion and transfers in the 40Ca + 58,64Ni systems

    NASA Astrophysics Data System (ADS)

    Bourgin, D.; Courtin, S.; Haas, F.; Goasduff, A.; Stefanini, A. M.; Montagnoli, G.; Montanari, D.; Corradi, L.; Huiming, J.; Scarlassara, F.; Fioretto, E.; Simenel, C.; Rowley, N.; Szilner, S.; Mijatović, T.

    2016-05-01

    Fusion cross sections have been measured in the 40Ca + 58Ni and 40Ca + 64Ni systems at energies around and below the Coulomb barrier. The 40Ca beam was delivered by the XTU Tandem accelerator of the Laboratori Nazionali di Legnaro and evaporation residues were measured at very forward angles with the LNL electrostatic beam deflector. Coupled-channels calculations were performed which highlight possible strong effects of neutron transfers on the fusion below the barrier in the 40Ca + 64Ni system. Microscopic time-dependent Hartree-Fock calculations have also been performed for both systems. Preliminary results are shown.

  1. Astrocytic TYMP and VEGFA drive blood-brain barrier opening in inflammatory central nervous system lesions.

    PubMed

    Chapouly, Candice; Tadesse Argaw, Azeb; Horng, Sam; Castro, Kamilah; Zhang, Jingya; Asp, Linnea; Loo, Hannah; Laitman, Benjamin M; Mariani, John N; Straus Farber, Rebecca; Zaslavsky, Elena; Nudelman, German; Raine, Cedric S; John, Gareth R

    2015-06-01

    In inflammatory central nervous system conditions such as multiple sclerosis, breakdown of the blood-brain barrier is a key event in lesion pathogenesis, predisposing to oedema, excitotoxicity, and ingress of plasma proteins and inflammatory cells. Recently, we showed that reactive astrocytes drive blood-brain barrier opening, via production of vascular endothelial growth factor A (VEGFA). Here, we now identify thymidine phosphorylase (TYMP; previously known as endothelial cell growth factor 1, ECGF1) as a second key astrocyte-derived permeability factor, which interacts with VEGFA to induce blood-brain barrier disruption. The two are co-induced NFκB1-dependently in human astrocytes by the cytokine interleukin 1 beta (IL1B), and inactivation of Vegfa in vivo potentiates TYMP induction. In human central nervous system microvascular endothelial cells, VEGFA and the TYMP product 2-deoxy-d-ribose cooperatively repress tight junction proteins, driving permeability. Notably, this response represents part of a wider pattern of endothelial plasticity: 2-deoxy-d-ribose and VEGFA produce transcriptional programs encompassing angiogenic and permeability genes, and together regulate a third unique cohort. Functionally, each promotes proliferation and viability, and they cooperatively drive motility and angiogenesis. Importantly, introduction of either into mouse cortex promotes blood-brain barrier breakdown, and together they induce severe barrier disruption. In the multiple sclerosis model experimental autoimmune encephalitis, TYMP and VEGFA co-localize to reactive astrocytes, and correlate with blood-brain barrier permeability. Critically, blockade of either reduces neurologic deficit, blood-brain barrier disruption and pathology, and inhibiting both in combination enhances tissue preservation. Suggesting importance in human disease, TYMP and VEGFA both localize to reactive astrocytes in multiple sclerosis lesion samples. Collectively, these data identify TYMP as an

  2. Advanced thermal barrier coating system development: Technical progress report

    SciTech Connect

    1996-12-11

    Objectives are to provide an improved TBC system with increased temperature capability and improved reliability. Such coating systems are essential to the ATS engine (gas turbine) meeting its objectives.

  3. Physical connectivity in the Mesoamerican Barrier Reef System inferred from 9 years of ocean color observations

    NASA Astrophysics Data System (ADS)

    Soto, I.; Andréfouët, S.; Hu, C.; Muller-Karger, F. E.; Wall, C. C.; Sheng, J.; Hatcher, B. G.

    2009-06-01

    Ocean color images acquired from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) from 1998 to 2006 were used to examine the patterns of physical connectivity between land and reefs, and among reefs in the Mesoamerican Barrier Reef System (MBRS) in the northwestern Caribbean Sea. Connectivity was inferred by tracking surface water features in weekly climatologies and a time series of weekly mean chlorophyll- a concentrations derived from satellite imagery. Frequency of spatial connections between 17 pre-defined, geomorphological domains that include the major reefs in the MBRS and river deltas in Honduras and Nicaragua were recorded and tabulated as percentage of connections. The 9-year time series of 466 weekly mean images portrays clearly the seasonal patterns of connectivity, including river plumes and transitions in the aftermath of perturbations such as hurricanes. River plumes extended offshore from the Honduras coast to the Bay Islands (Utila, Cayo Cochinos, Guanaja, and Roatán) in 70% of the weekly mean images. Belizean reefs, especially those in the southern section of the barrier reef and Glovers Atoll, were also affected by riverine discharges in every one of the 9 years. Glovers Atoll was exposed to river plumes originating in Honduras 104/466 times (22%) during this period. Plumes from eastern Honduras went as far as Banco Chinchorro and Cozumel in Mexico. Chinchorro appeared to be more frequently connected to Turneffe Atoll and Honduran rivers than with Glovers and Lighthouse Atolls, despite their geographic proximity. This new satellite data analysis provides long-term, quantitative assessments of the main pathways of connectivity in the region. The percentage of connections can be used to validate predictions made using other approaches such as numerical modeling, and provides valuable information to ecosystem-based management in coral reef provinces.

  4. Implementation of health risk assessments with family health history: barriers and benefits.

    PubMed

    Wu, R Ryanne; Orlando, Lori A

    2015-09-01

    Health risk assessments provide an opportunity to emphasise health promotion and disease prevention for individuals and populations at large. A key component of health risk assessments is the detailed collection of family health history information. This information is helpful in determining risk both for common chronic conditions and more rare diseases as well. While the concept of health risk assessments has been around since the Framingham Heart Study was launched in the 1950s, and such assessments are commonly performed in the workplace today, the US healthcare system has been slow to embrace them and the emphasis on prevention that they represent. Before wider implementation of health risk assessments within healthcare can be seen, several concerns must be addressed: (1) provider impact, (2) patient impact, (3) validity of patient-entered data and (4) health outcomes effect. Here, we describe recent developments in health risk assessment design that are helping to address these issues.

  5. Development of the barrier system at Ferry Beach, Maine--Evidence of transgressive and regressive phases

    SciTech Connect

    Van Heteren, S.; Fitzgerald, D.M. . Dept. of Geology); Fink, L.K. Jr. . Dept. of Geological Sciences)

    1993-03-01

    Ferry Beach is part of a barrier system that borders the southern end of the Saco Embayment. This portion of the coast is characterized by mesotidal conditions and low wave energy. The beaches in this area are fronted by a low gradient sandy offshore and backed by a continuous foredune ridge. The backbarrier consists of fresh water ponds at Ferry Beach, in the central part, and salt marshes adjacent to Saco River and Goosefare Brook. New ground-penetrating radar and vibracore data, supplemented with topographic profiles, have enabled the delineation and interpretation of the major stratigraphic units present at Ferry Beach. The internal structure of the barrier lithosome and backbarrier sedimentary unit shows evidence of three phases in the late Holocene development of the study area. The first, transgressive phase is identified in the unconformity between glaciomarine clays of the Presumpscot Formation and overlying backbarrier, barrier, and shoreface units. The second, transitional phase is recognized as a distinctly outlined sandy unit with landward and southward dipping layers on top of backbarrier and shoreface deposits. The unit is inferred to be either a recurved spit deposit or part of a new barrier incompletely welded to the older beach ridges. The third, regressive phase has resulted in the present-day beach ridge system. The barrier lithosome associated with this phase is characterized by 150 m of offshore dipping layers. The evolutionary style of the Ferry Beach barrier system is likely linked to variations in rates of relative sea-level rise and sediment supply. Rapid rise of relative sea level was the determining factor during Phase 1, while offshore and longshore (notably from the Saco River) sediment supply during the Holocene sediment maximum caused the barrier expansion during Phases 2 and 3.

  6. Spatiotemporal variability of sedimentology and morphology in the East Frisian barrier island system

    NASA Astrophysics Data System (ADS)

    Herrling, Gerald; Winter, Christian

    2016-08-01

    The highly dynamic East Frisian barrier island system (southern North Sea) is characterized by a complex morphology of tidal inlets, ebb-tidal deltas and foreshore beaches that reacts to storms and fair-weather conditions with characteristic patterns of sediment grain-size distributions. The morphological and sedimentological response to varying hydrodynamic conditions yet occurs in short time spans that are not covered by common monitoring strategies with measuring intervals typically of years. This study applies process-based numerical modelling with multiple sediment fractions to interpolate morphological states in time between bathymetrical surveys conducted in the summer months of 2004 and 2006. Morphodynamic simulations driven by real-time boundary conditions of tides, wind and waves are carried out for a representative period of 2 years. The spatiotemporal variability of the nearshore sedimentology and morphology is assessed by graded ranges of bed dynamics (i.e. bed elevation range) and the definition of sediment grain-size variability (i.e. mean diameter range). The effect of storm events and timescales of the sedimentological adaptation after storms to typical fair-weather conditions are exemplified at an ebb-tidal delta lobe where the morphological and sedimentological variability is found to be largest in the study area. The proposed method may serve to identify areas of high sedimentological and morphological activity for system understanding or in the framework of coastal monitoring strategies.

  7. Advanced thermal barrier coating system development: Technical progress report

    SciTech Connect

    1996-08-07

    Objectives are to provide an improved TBC system with increased temperature capability and improved reliability, for the Advanced Turbine Systems program (gas turbine). The base program consists of three phases: Phase I, program planning (complete); Phase II, development; and Phase III (selected specimen-bench test). Work is currently being performed in Phase II.

  8. Matched Bipartite Digraph Representation of Generalized Dynamical System Formed by One-way Barriers

    NASA Astrophysics Data System (ADS)

    Li, John; Mahoney, John; Mitchell, Kevin; Tom Solomon Collaboration

    2014-03-01

    We studied a dynamical system with stable and unstable manifolds that behave as one-way barriers, instead of separatrices in traditional dynamical system that are two-way barriers. This asymmetry gives rise to a richer dynamical behavior such as the overlapping of basins of attraction. The recently developed Burning Invariant Manifold (BIM) theory took a dynamical system approach to understand front propagation in Advection-Reaction-Diffusion systems, which have BIMs as the one-way barriers. Through numerical simulations under BIM theory, we found that although both unstable and stable BIMs are one-way barriers, unstable BIMs are the ones that we can experimentally observe the fronts converging onto, and the stable BIMs act as the basin boundaries. We further hypothesized a duality relation between the stable and unstable BIMs. Under the duality hypothesis, we developed a mechanism of the behavior of the system by reducing it back to a traditional system based on topology, and we found a simplification of the system by to summarize the topological information into a Matched Bipartite directed graph (MB digraph). This work was supported by the US National Science Foundation under grant PHY-0748828 and NSF Fellowship DGE-0937362.

  9. Thermal Performance Evaluation of Attic Radiant Barrier Systems Using the Large Scale Climate Simulator (LSCS)

    SciTech Connect

    Shrestha, Som S; Miller, William A; Desjarlais, Andre Omer

    2013-01-01

    Application of radiant barriers and low-emittance surface coatings in residential building attics can significantly reduce conditioning loads from heat flow through attic floors. The roofing industry has been developing and using various radiant barrier systems and low-emittance surface coatings to increase energy efficiency in buildings; however, minimal data are available that quantifies the effectiveness of these technologies. This study evaluates performance of various attic radiant barrier systems under simulated summer daytime conditions and nighttime or low solar gain daytime winter conditions using the large scale climate simulator (LSCS). The four attic configurations that were evaluated are 1) no radiant barrier (control), 2) perforated low-e foil laminated oriented strand board (OSB) deck, 3) low-e foil stapled on rafters, and 4) liquid applied low-emittance coating on roof deck and rafters. All test attics used nominal RUS 13 h-ft2- F/Btu (RSI 2.29 m2-K/W) fiberglass batt insulation on attic floor. Results indicate that the three systems with radiant barriers had heat flows through the attic floor during summer daytime condition that were 33%, 50%, and 19% lower than the control, respectively.

  10. North Carolina Cooperative Extension Professionals' Climate Change Perceptions, Willingness, and Perceived Barriers to Programming: An Educational Needs Assessment

    ERIC Educational Resources Information Center

    Burnett, Rachel E.; Vuola, Aaron J.; Megalos, Mark A.; Adams, Damian C.; Monroe, Martha C.

    2014-01-01

    The educational needs assessment reported here measured North Carolina Cooperative Extension (NCCE) professionals' perceptions of global warming and identified barriers to climate change programming. Survey results from 400 NCCE professionals show 70% are cautious, concerned, or alarmed about global warming. Liberal and female Extension…

  11. Edible moisture barriers: how to assess of their potential and limits in food products shelf-life extension?

    PubMed

    Bourlieu, C; Guillard, V; Vallès-Pamiès, B; Guilbert, S; Gontard, N

    2009-05-01

    Control of moisture transfer inside composite food products or between food and its environment remains today a major challenge in food preservation. A wide rage of film-forming compounds is now available and facilitates tailoring moisture barriers with optimized functional properties. Despite these huge potentials, a realistic assessment of the film or coating efficacy is still critical. Due to nonlinear water sorption isotherms, water-dependent diffusivities, and variations of physical state, modelling transport phenomena through edible barriers is complex. Water vapor permeability can hardly be considered as an inherent property of films and only gives a relative indication of the barrier efficacy. The formal or mechanistic models reported in literature that describe the influence of testing conditions on the barrier properties of edible films are reviewed and discussed. Most of these models have been validated on a narrow range of conditions. Conversely, few original predictive models based on Fick's Second Law have been developed to assess shelf-life extension of food products including barriers. These models, assuming complex and realistic hypothesis, have been validated in various model foods. The development of nondestructive methods of moisture content measurement should speed up model validation and allow a better comprehension of moisture transfer through edible films.

  12. Enhancement of the magnetic anisotropy barrier in critical long range spin systems.

    PubMed

    Borgonovi, F; Celardo, G L

    2013-03-13

    Magnetic materials are usually characterized by anisotropy energy barriers which dictate the timescale of the magnetization decay and consequently the magnetic stability of the sample. Here we consider magnetization decay for spin systems in a d = 3 cubic lattice with an isotropic Heisenberg interaction decaying as a power law with a critical exponent α = d and on-site anisotropy. We show that the anisotropy energy barrier can be determined from the ergodicity breaking energy of the corresponding isolated system and that, unlike in the case of nearest neighbour interaction, the anisotropy energy barrier grows as the particle volume, V, and not as the cross-sectional area.

  13. Advanced thermal barrier coating system development. Technical progress report

    SciTech Connect

    1996-10-04

    The objectives of the program are to provide an improved TBC system with increased temperature capability and improved reliability relative to current state of the art TBC systems. The development of such a coating system is essential to the ATS engine meeting its objectives. The base program consists of three phases: Phase 1: Program Planning--Complete; Phase 2: Development; Phase 3: Selected Specimen--Bench Test. Work is currently being performed in Phase 2 of the program. In Phase 2, process improvements will be married with new bond coat and ceramic materials systems to provide improvements over currently available TBC systems. Coating reliability will be further improved with the development of an improved lifing model and NDE techniques. This will be accomplished by conducting the following program tasks: II.1 Process Modeling; II.2 Bond Coat Development; II.3 Analytical Lifing Model; II.4 Process Development; II.5 NDE, Maintenance and Repair; II.6 New TBC Concepts. A brief summary of progress made in each of these 6 areas is given.

  14. Advanced thermal barrier coating system development. Technical progress report

    SciTech Connect

    1996-06-10

    The objectives of the program are to provide an improved TBC system with increased temperature capability and improved reliability relative to current state of the art TBC systems. The development of such a coating system is essential to the ATS engine meeting its objectives. The base program consists of three phases: Phase 1: Program Planning--Complete; Phase 2: Development; Phase 3: Selected Specimen--Bench Test. Work is currently being performed in Phase 2 of the program. In Phase 2, process improvements will be married with new bond coat and ceramic materials systems to provide improvements over currently available TBC systems. Coating reliability will be further improved with the development of an improved lifing model and NDE techniques. This will be accomplished by conducting the following program tasks: II.1 Process Modeling; II.2 Bond Coat Development; II.3 Analytical Lifing Model; II.4 Process Development; II.5 NDE, Maintenance and Repair; II.6 New TBC Concepts. A brief summary is given of progress made in each of these 6 areas.

  15. Evaluation of a transient barrier trapping system to manage the canyon fly (Diptera: Muscidae).

    PubMed

    Ekanayake, Panchali K; Gerry, Alec C

    2014-01-01

    ABSTRACT A circular perimeter barrier of CO,-baited Centers for Disease Control and Prevention (CDC) suction traps (without the light) was placed at a hilltop location in southern California known for high "canyon fly" activity, to determine whether a transiently operated barrier trapping system using attractive traps would reduce the number of these nuisance flies to successfully reach a human host within the protected area Preliminary studies demonstrated that the number of flies captured by a human host was reduced when a single CO2 trap was placed < or =20 m from the host, an indication that these traps are attractive enough to reduce fly pressure on nearby human hosts. The use of eight transiently operated CO2 traps placed equidistant along either a 15- or 5-m radius barrier perimeter significantly reduced the number of flies to reach a human host within the protected area Attack rates at the protected human host were reduced by a maximum of 51% in the presence of a protective barrier. However, with attack rates on a human host in the hundreds of flies per minute at the study site, this level of protection was not deemed sufficient for recommendation of this technique to homeowners or others who want temporary suppression of these nuisance flies in a limited area, such as a backyard. Implications of using a transient barrier trapping system to manage canyon flies are discussed.

  16. PROGRESS OF THE AVNG SYSTEM - ATTRIBUTE VERIFICATION SYSTEM WITH INFORMATION BARRIERS FOR MASS AND ISOTOPICS MEASUREMENTS

    SciTech Connect

    Budnikov, D; Bulatov, M; Jarikhine, I; Lebedev, B; Livke, A; Modenov, A; Morkin, A; Razinkov, S; Safronov, S; Tsaregorodtsev, D; Vlokh, A; Yakovleva, S; Elmont, T; Langner, D; MacArthur, D; Mayo, D; Smith, M; Luke, S J

    2005-05-27

    An attribute verification system (AVNG) with information barriers for mass and isotopics measurements has been designed and its fabrication is nearly completed. The AVNG is being built by scientists at the Russian Federal Nuclear Center-VNIIEF, with support of Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Such a system could be used to verify the presence of several unclassified attributes of classified material with no classified information release. The system is comprised of a neutron multiplicity counter and gamma-spectrometry system based on a high purity germanium gamma detector (nominal relative efficiency {at} 1332 keV 50%) and digital gamma-ray spectrometer DSPEC{sup PLUS}. The neutron multiplicity counter is a three ring counter with 164 {sup 3}He tubes. The system was designed to measure prototype containers 491 mm in diameter and 503 mm high. This paper provides a brief history of the project and documents the progress of this effort with drawings and photographs.

  17. Progress of the AVNG System - Attribute Verification System with Information Barriers for Mass Isotopics Measurements.

    SciTech Connect

    Budnikov, D.; Bulatov, M.; Jarikhine, I.; Lebedev, B.; Livke, A.; Modenov, A.; Morkin, A.; Razinkov, S.; Tsaregorodtsev, D.; Vlokh, A.; Yakovleva, S.; Elmont, T. H.; Langner, D. C.; MacArthur, D. W.; Mayo, D. R.; Smith, M. K.; Luke, S. J.

    2005-01-01

    An attribute verification system (AVNG) with information barriers for mass and isotopics measurements has been designed and its fabrication is nearly completed. The AVNG is being built by scientists at the Russian Federal Nuclear Center-VNIIEF, with support of Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Such a system could be used to verify the presence of several unclassified attributes of classified material with no classified information release. The system is comprised of a neutron multiplicity counter and gamma-spectrometry system based on a high purity germanium gamma detector (nominal relative efficiency @ 1332 keV 50%) and digital gamma-ray spectrometer DSPEC{sup PLUS}. The neutron multiplicity counter is a three ring counter with 164 {sup 3}He tubes. The system was designed to measure prototype containers 491 mm in diameter and 503 mm high. This paper provides a brief history of the project and documents the progress of this effort with drawings and photographs.

  18. Portable Immune-Assessment System

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Stowe, Raymond P.; Mishra, Saroj K.

    1995-01-01

    Portable immune-assessment system developed for use in rapidly identifying infections or contaminated environment. System combines few specific fluorescent reagents for identifying immune-cell dysfunction, toxic substances, buildup of microbial antigens or microbial growth, and potential identification of pathogenic microorganisms using fluorescent microplate reader linked to laptop computer. By using few specific dyes for cell metabolism, DNA/RNA conjugation, specific enzyme activity, or cell constituents, one makes immediate, onsite determination of person's health or of contamination of environment.

  19. The Gulf Coast Vulnerability Assessment: Mangrove, Tidal Emergent Marsh, Barrier Islands, and Oyster Reef

    USGS Publications Warehouse

    Watson, Amanda; Reece, Joshua S.; Tirpak, Blair; Edwards, Cynthia Kallio; Geselbracht, Laura; Woodrey, Mark; LaPeyre, Megan K.; Dalyander, Patricia (Soupy)

    2015-01-01

    Climate, sea level rise, and urbanization are undergoing unprecedented levels of combined change and are expected to have large effects on natural resources—particularly along the Gulf of Mexico coastline (Gulf Coast). Management decisions to address these effects (i.e., adaptation) require an understanding of the relative vulnerability of various resources to these stressors. To meet this need, the four Landscape Conservation Cooperatives along the Gulf partnered with the Gulf of Mexico Alliance to conduct this Gulf Coast Vulnerability Assessment (GCVA). Vulnerability in this context incorporates the aspects of exposure and sensitivity to threats, coupled with the adaptive capacity to mitigate those threats. Potential impact and adaptive capacity reflect natural history features of target species and ecosystems. The GCVA used an expert opinion approach to qualitatively assess the vulnerability of four ecosystems: mangrove, oyster reef, tidal emergent marsh, and barrier islands, and a suite of wildlife species that depend on them. More than 50 individuals participated in the completion of the GCVA, facilitated via Ecosystem and Species Expert Teams. Of the species assessed, Kemp’s ridley sea turtle was identified as the most vulnerable species across the Gulf Coast. Experts identified the main threats as loss of nesting habitat to sea level rise, erosion, and urbanization. Kemp’s ridley also had an overall low adaptive capacity score due to their low genetic diversity, and higher nest site fidelity as compared to other assessed species. Tidal emergent marsh was the most vulnerable ecosystem, due in part to sea level rise and erosion. In general, avian species were more vulnerable than fish because of nesting habitat loss to sea level rise, erosion, and potential increases in storm surge. Assessors commonly indicated a lack of information regarding impacts due to projected changes in the disturbance regime, biotic interactions, and synergistic effects in both

  20. Laboratory assessment of flexible thin-film membranes as a passive barrier to radon gas diffusion.

    PubMed

    Daoud, W Z; Renken, K J

    2001-05-14

    This paper presents the experimental results of utilizing a flexible thin-film membrane as a passive barrier to radon gas diffusion. Nine commercially available membranes of various compositions and thicknesses were evaluated as retardant to radon gas diffusion. The radon gas concentration ratios across the thin-film membranes alone and in combination with an adjacent concrete sample (effective diffusion coefficient) were measured in a laboratory system with state-of-the-art instrumentation. An 8.89-cm diameter, 10.2-cm thick concrete sample of standard composition (w/c = 0.5 and cement:sand:gravel = 1:2:4) was used to simulate a basement and slab-on-grade foundation typical of Wisconsin. The radon gas transport characteristics of this concrete sample (porosity, permeability and diffusion) are documented. The experimentation has identified two superior flexible thin-film membranes that may be employed as effective barriers to radon gas diffusion. These include: Polyethylene Naphthalate (7.62 x 10(-5) m) and Polyethylene Terephthalate Glycol, PETG (7.62 x 10(-5) and 1.27 x 10(-4) m) which had average diffusion coefficients, D, of 4.10 x 10(-14) and 1.66 x 10(-14) m2 s(-1), respectively. Measurements of the effective membrane/concrete diffusion coefficient yielded a further average reduction in D of 98% for the Polyethylene Naphthalate and 96% for the PETG. Details of the experimental set-ups and procedures are described. The results of this investigation have shown that the application of an effective thin-film membrane adjacent to an intact concrete slab can significantly reduce the diffusion of radon gas entry. Therefore, the employment of a flexible thin-film membrane should be considered as a viable radon reduction technology method for residential new construction.

  1. Method of in situ retrieval of contaminants or other substances using a barrier system and leaching solutions

    DOEpatents

    Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

    2006-12-26

    Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

  2. Barriers to Excellence: The Culture of Silence in School Systems.

    ERIC Educational Resources Information Center

    Rusch, Edith A.

    Little is known about how restructuring networks actually affect the cultures of school systems. This report examines the creation of an "island" of reform in a school district in northwest Ohio. The research emanated from the discovery of a new "island" in northwest Ohio called the Pathfinder Network. The group formed through like-minded…

  3. Improving understanding of near-term barrier island evolution through multi-decadal assessment of morphologic change

    USGS Publications Warehouse

    Lentz, Erika E.; Hapke, Cheryl J.; Stockdon, Hilary F.; Hehre, Rachel E.

    2013-01-01

    Observed morphodynamic changes over multiple decades were coupled with storm-driven run-up characteristics at Fire Island, New York, to explore the influence of wave processes relative to the impacts of other coastal change drivers on the near-term evolution of the barrier island. Historical topography was generated from digital stereo-photogrammetry and compared with more recent lidar surveys to quantify near-term (decadal) morphodynamic changes to the beach and primary dune system between the years 1969, 1999, and 2009. Notably increased profile volumes were observed along the entirety of the island in 1999, and likely provide the eolian source for the steady dune crest progradation observed over the relatively quiescent decade that followed. Persistent patterns of erosion and accretion over 10-, 30-, and 40-year intervals are attributable to variations in island morphology, human activity, and variations in offshore bathymetry and island orientation that influence the wave energy reaching the coast. Areas of documented long-term historical inlet formation and extensive bayside marsh development show substantial landward translation of the dune–beach profile over the near-term period of this study. Correlations among areas predicted to overwash, observed elevation changes of the dune crestline, and observed instances of overwash in undeveloped segments of the barrier island verify that overwash locations can be accurately predicted in undeveloped segments of coast. In fact, an assessment of 2012 aerial imagery collected after Hurricane Sandy confirms that overwash occurred at the majority of near-term locations persistently predicted to overwash. In addition to the storm wave climate, factors related to variations within the geologic framework which in turn influence island orientation, offshore slope, and sediment supply impact island behavior on near-term timescales.

  4. The risk assessment information system

    SciTech Connect

    Kerr, S.B.; Bonczek, R.R.; McGinn, C.W.; Land, M.L.; Bloom, L.D.; Sample, B.E.; Dolislager, F.G.

    1998-06-01

    In an effort to provide service-oriented environmental risk assessment expertise, the Department of Energy (DOE) Center for Risk Excellence (CRE) and DOE Oak Ridge Operations Office (ORO) are sponsoring Oak Ridge National Laboratory (ORNL) to develop a web-based system for disseminating risk tools and information to its users. This system, the Risk Assessment Information System (RAIS), was initially developed to support the site-specific needs of the DOE-ORO Environmental Restoration Risk Assessment Program. With support from the CRE, the system is currently being expanded to benefit all DOE risk information users and can be tailored to meet site-specific needs. Taking advantage of searchable and executable databases, menu-driven queries, and data downloads, using the latest World Wide Web technologies, the RAIS offers essential tools that are used in the risk assessment process or anywhere from project scoping to implementation. The RAIS tools can be located directly at http://risk.lsd.ornl.gov/homepage/rap{_}tool.htm or through the CRE`s homepage at http://www.doe.gov/riskcenter/home.html.

  5. 76 FR 56215 - John H. Chafee Coastal Barrier Resources System; Baldwin and Mobile Counties, AL; Availability of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... ADDRESSES section above. The Service will also accept digital Geographic Information System (GIS) data files... Fish and Wildlife Service John H. Chafee Coastal Barrier Resources System; Baldwin and Mobile Counties... (Service), announce the availability of a John H. Chafee Coastal Barrier Resources System (CBRS)...

  6. The Role of Backbarrier Filling in the Evolution of a Barrier Island System

    NASA Astrophysics Data System (ADS)

    Hein, C. J.; Fitzgerald, D. M.; Stone, B. D.; Carruthers, E.; Gontz, A. M.

    2009-12-01

    Barrier islands develop through a variety of processes, including spit accretion, barrier elongation, breaching and inlet filling. New geophysical and sedimentological data collected along a barrier system in the western Gulf of Maine provide a means of documenting a unique process of barrier evolution involving backbarrier infilling and ensuing closure of an ancient tidal inlet. Plum Island is located along a mixed-energy, tide-dominated coastline bounded by estuaries and backed by an extensive system of salt marsh and tidal creeks. Following the regional glacioisostatic lowstand of approximately -45 m at 12 ka, the Holocene transgression reworked a late Pleistocene regressive braid plain and lowstand delta. Sediments driven onshore during the transgression and derived from the Merrimack River fed the developing barrier system. Radiocarbon dates suggests that backbarrier sands began accumulating at the modern site of Plum Island at approximately 9 ka. At this time, the barrier was composed of several discrete islands separated by inlets and situated offshore of modern Plum Island. Shallow seismic and ground penetrating radar (GPR) data confirm the existence of lower stand riverine/tidal channels extending onto the shallow shelf. Coincident with the slowing of relative sea level rise, Plum Island began to form in its current location approximately 5.5 ka, establishing its modern form by about 2.5 ka. Sediment cores and GPR data demonstrate that the barrier lithosome is 5 to 15 m thick and evolved through initial aggradation followed by southerly spit accretion and progradation. The discovery of a multiple inlet channel system reoccupying the area carved by the lowstand Parker River indicates that central Plum Island underwent a complex developmental history. Cores through the inlet sequence consist of fine to medium sand with repetitive interbedded coarse sand units, marking high-energy depositional events associated with spit accretion and displacement of the

  7. Environmental impact assessment in urban transport planning: Exploring process-related barriers in Spanish practice

    SciTech Connect

    Soria-Lara, Julio A. Bertolini, Luca Brömmelstroet, Marco te

    2015-01-15

    The effectiveness of EIA for evaluating transport planning projects is increasingly being questioned by practitioners, institutions and scholars. The academic literature has traditionally focused more on solving content-related problems with EIA (i.e. the measurement of environmental effects) than on process-related issues (i.e. the role of EIA in the planning process and the interaction between key actors). Focusing only on technical improvements is not sufficient for rectifying the effectiveness problems of EIA. In order to address this knowledge gap, the paper explores how EIA is experienced in the Spanish planning context and offers in-depth insight into EIA process-related issues in the field of urban transport planning. From the multitude of involved actors, the research focuses on exploring the perceptions of the two main professional groups: EIA developers and transport planners. Through a web-based survey we assess the importance of process-related barriers to the effective use of EIA in urban transport planning. The analyses revealed process issues based fundamentally on unstructured stakeholders involvement and an inefficient public participation - Highlights: • Qualitative research on perceptions of EIA participants on EIA processes. • Web-based survey with different participants (EIA-developers; transport planners). • It was seen an inefficient participation of stakeholders during the EIA processes.

  8. Objective structured clinical examination for pharmacy students in Qatar: cultural and contextual barriers to assessment.

    PubMed

    Wilby, K J; Black, E K; Austin, Z; Mukhalalati, B; Aboulsoud, S; Khalifa, S I

    2016-07-10

    This study aimed to evaluate the feasibility and psychometric defensibility of implementing a comprehensive objective structured clinical examination (OSCE) on the complete pharmacy programme for pharmacy students in a Middle Eastern context, and to identify facilitators and barriers to implementation within new settings. Eight cases were developed, validated, and had standards set according to a blueprint, and were assessed with graduating pharmacy students. Assessor reliability was evaluated using inter-class coefficients (ICCs). Concurrent validity was evaluated by comparing OSCE results to professional skills course grades. Field notes were maintained to generate recommendations for implementation in other contexts. The examination pass mark was 424 points out of 700 (60.6%). All 23 participants passed. Mean performance was 74.6%. Low to moderate inter-rater reliability was obtained for analytical and global components (average ICC 0.77 and 0.48, respectively). In conclusion, OSCE was feasible in Qatar but context-related validity and reliability concerns must be addressed prior to future iterations in Qatar and elsewhere.

  9. Thermal Cycling Assessment of Steel-Based Thermal Barrier Coatings for Al Protection

    NASA Astrophysics Data System (ADS)

    Poirier, Dominique; Lamarre, Jean-Michel; Legoux, Jean-Gabriel

    2015-01-01

    There is a strong interest from the transportation industry to achieve vehicle weight reduction through the replacement of steel components by aluminum parts. For some applications, aluminum requires protective coatings due to its limited wear and lower temperature resistance compared to steel. The objective of this study was to assess the potential of amorphous-type plasma-sprayed steel coatings and conventional arc-sprayed steel coatings as thermal barrier coatings, mainly through the evaluation of their spalling resistance under thermal cycling. The microstructures of the different coatings were first compared via SEM. The amorphicity of the coatings produced via plasma spraying of specialized alloyed steel and the crystalline phases of the conventional arc-sprayed steel coatings were confirmed through x-ray diffraction. The thermal diffusivity of all coatings produced was measured to be about a third of that of bulk stainless steel. Conventional arc-sprayed steel coatings typically offered better spalling resistance under thermal cycling than steel-based amorphous coatings due probably to their higher initial bond strength. However, the presence of vertical cracks in the steel-based amorphous coatings was found to have a beneficial effect on their thermal cycling resistance. The amorphous plasma-sprayed steel coatings presented indications of recrystallization after their exposure to high temperature.

  10. The Development and Evaluation of a Measure Assessing School Nurses' Perceived Barriers to Addressing Pediatric Obesity

    ERIC Educational Resources Information Center

    Wu, Yelena P.; Steele, Ric G.

    2011-01-01

    School nurses represent an important resource for addressing pediatric obesity and weight-related health. However, school nurses perceive numerous barriers that prevent them from addressing the weight-related health of students. The current study developed and tested a new, comprehensive measure of nurses' perceptions of 10 types of barriers to…

  11. Assessment of blood–brain barrier disruption using dynamic contrast-enhanced MRI. A systematic review

    PubMed Central

    Heye, Anna K.; Culling, Ross D.; Valdés Hernández, Maria del C.; Thrippleton, Michael J.; Wardlaw, Joanna M.

    2014-01-01

    There is increasing recognition of the importance of blood–brain barrier (BBB) disruption in aging, dementia, stroke and multiple sclerosis in addition to more commonly-studied pathologies such as tumors. Dynamic contrast-enhanced MRI (DCE-MRI) is a method for studying BBB disruption in vivo. We review pathologies studied, scanning protocols and data analysis procedures to determine the range of available methods and their suitability to different pathologies. We systematically review the existing literature up to February 2014, seeking studies that assessed BBB integrity using T1-weighted DCE-MRI techniques in animals and humans in normal or abnormal brain tissues. The literature search provided 70 studies that were eligible for inclusion, involving 417 animals and 1564 human subjects in total. The pathologies most studied are intracranial neoplasms and acute ischemic strokes. There are large variations in the type of DCE-MRI sequence, the imaging protocols and the contrast agents used. Moreover, studies use a variety of different methods for data analysis, mainly based on model-free measurements and on the Patlak and Tofts models. Consequently, estimated KTrans values varied widely. In conclusion, DCE-MRI is shown to provide valuable information in a large variety of applications, ranging from common applications, such as grading of primary brain tumors, to more recent applications, such as assessment of subtle BBB dysfunction in Alzheimer's disease. Further research is required in order to establish consensus-based recommendations for data acquisition and analysis and, hence, improve inter-study comparability and promote wider use of DCE-MRI. PMID:25379439

  12. Development and validation of a survey to assess barriers to drug use in patients with chronic heart failure.

    PubMed

    Simpson, Scot H; Johnson, Jeffrey A; Farris, Karen B; Tsuyuki, Ross T

    2002-09-01

    Scot H. Simpson, Pharm.D., M.Sc., Jeffrey A. Johnson, Ph.D., Karen B. Farris, Ph.D., and Ross T. Tsuyuki, Pharm.D., M.Sc. Objective. To report the development of and initial experience with a survey designed to assess patient-perceived barriers to drug use in ambulatory patients with heart failure. Methods. The Barriers to Medication Use (BMU) survey, developed from previous qualitative work by our group, was administered to 128 consecutive patients attending an outpatient heart failure clinic. The first 42 patients to return the survey were mailed a second survey to evaluate response stability over time. The survey contained 31 questions in five barrier domains (knowledge, previous drug therapy experiences, social support, communication, and relationship with health care professionals). Patients also completed the Minnesota Living with Heart Failure (MLHF) questionnaire and a self-reported drug use scale. Frequency of drug refills was used to estimate adherence. Reliability and construct validity of the BMU survey were assessed using correlation coefficients. Results. Response rates were 89% and 93% for the first and retest surveys, respectively The BMU survey showed modest internal consistency in the overall survey and in two of the five barrier domains. Responses to the first and retest surveys showed good stability over time in the overall survey and in four of the five barrier domains. Patients with good adherence reported few barriers; however, the association was not strong (Pearson correlation coefficient r = -0.14, p=0.14). Patients who reported few barriers also reported better MLHF scores (r = 0.42, p < 0.001), with the strongest association in the social support domain (r = 0.53; p < 0.001). All respondents reported having a good relationship with health care professionals. The most common barriers to drug use were poor support networks and previous adverse reactions. Conclusion. The BMU survey demonstrated reasonable reliability and validity

  13. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    ERIC Educational Resources Information Center

    Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

    2011-01-01

    This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

  14. Stuck in a Loop: Individual and System Barriers for Job Seekers with Disabilities

    ERIC Educational Resources Information Center

    Hall, Jean P.; Parker, Kathy

    2010-01-01

    Research conducted within Temporary Assistance to Needy Families (Personal Responsibility and Work Opportunity Reconciliation Act of 1996) and Workforce Investment Act of 1998 systems indicates pervasive issues hindering program effectiveness for job seekers with disabilities. This population frequently experiences employment barriers beyond those…

  15. Underutilization of Mental Health Services among College Students: An Examination of System-Related Barriers

    ERIC Educational Resources Information Center

    Marsh, Carey N.; Wilcoxon, S. Allen

    2015-01-01

    Despite the documented benefits of counseling and mental health services on academic performance and degree attainment, only about 10% of psychologically distressed college students ever seek professional help. This investigation examined mental health care system-related barriers that might distinguish help seekers from nonhelp seekers among…

  16. Barriers to Systemic, Effective, and Sustainable Technology Use in High School Classrooms

    ERIC Educational Resources Information Center

    Daniels, Jason Scott; Jacobsen, Michele; Varnhagen, Stanley; Friesen, Sharon

    2013-01-01

    The purpose of the Technology and High School Success (THSS) initiative was to encourage innovative strategies focused on improving provincial high school completion rates, using technology and student-centered learning to engage student interest. The primary purpose of this paper is to report on barriers that impede systemic, effective and…

  17. Perceived barriers of heart failure nurses and cardiologists in using clinical decision support systems in the treatment of heart failure patients

    PubMed Central

    2013-01-01

    Background Clinical Decision Support Systems (CDSSs) can support guideline adherence in heart failure (HF) patients. However, the use of CDSSs is limited and barriers in working with CDSSs have been described as a major obstacle. It is unknown if barriers to CDSSs are present and differ between HF nurses and cardiologists. Therefore the aims of this study are; 1. Explore the type and number of perceived barriers of HF nurses and cardiologists to use a CDSS in the treatment of HF patients. 2. Explore possible differences in perceived barriers between two groups. 3. Assess the relevance and influence of knowledge management (KM) on Responsibility/Trust (R&T) and Barriers/Threats (B&T). Methods A questionnaire was developed including; B&T, R&T, and KM. For analyses, descriptive techniques, 2-tailed Pearson correlation tests, and multiple regression analyses were performed. Results The response- rate of 220 questionnaires was 74%. Barriers were found for cardiologists and HF nurses in all the constructs. Sixty-five percent did not want to be dependent on a CDSS. Nevertheless thirty-six percent of HF nurses and 50% of cardiologists stated that a CDSS can optimize HF medication. No relationship between constructs and age; gender; years of work experience; general computer experience and email/internet were observed. In the group of HF nurses a positive correlation (r .33, P<.01) between years of using the internet and R&T was found. In both groups KM was associated with the constructs B&T (B=.55, P=<.01) and R&T (B=.50, P=<.01). Conclusions Both cardiologists and HF-nurses perceived barriers in working with a CDSS in all of the examined constructs. KM has a strong positive correlation with perceived barriers, indicating that increasing knowledge about CDSSs can decrease their barriers. PMID:23622342

  18. Power Systems Development Facility. Environmental Assessment

    SciTech Connect

    Not Available

    1993-06-01

    The objective of the PSDF would be to provide a modular facility which would support the development of advanced, pilot-scale, coal-based power systems and hot gas clean-up components. These pilot-scale components would be designed to be large enough so that the results can be related and projected to commercial systems. The facility would use a modular approach to enhance the flexibility and capability for testing; consequently, overall capital and operating costs when compared with stand-alone facilities would be reduced by sharing resources common to different modules. The facility would identify and resolve technical barrier, as well as-provide a structure for long-term testing and performance assessment. It is also intended that the facility would evaluate the operational and performance characteristics of the advanced power systems with both bituminous and subbituminous coals. Five technology-based experimental modules are proposed for the PSDF: (1) an advanced gasifier module, (2) a fuel cell test module, (3) a PFBC module, (4) a combustion gas turbine module, and (5) a module comprised of five hot gas cleanup particulate control devices. The final module, the PCD, would capture coal-derived ash and particles from both the PFBC and advanced gasifier gas streams to provide for overall particulate emission control, as well as to protect the combustion turbine and the fuel cell.

  19. Advanced thermal barrier system bond coatings for use on Ni, Co-, and Fe-base alloy substrates

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1985-01-01

    New and improved Ni-, Co-, and Fe-base bond coatings have been identified for the ZrO2-Y2O3 thermal barrier coatings to be used on NI-, Co-, and Fe-base alloy substrates. These bond coatings were evaluated in a cyclic furnace between 1120 and 1175 C. It was found that MCrAlYb (where M = Ni, Co, or Fe) bond coating thermal barrier systems. The longest life was obtained with the FeCrAlYb thermal barrier system followed by NiCrAlYb and CoCrAlYb thermal barrier systems in that order.

  20. Assessment of Residential GSHP System

    SciTech Connect

    Liu, Xiaobing

    2010-09-01

    This report first briefly reviews geothermal heat pump (GHP) technology and the current status of the GHP industry in the United States. Then it assesses the potential national benefits, in terms of energy savings, reduced summer peak electrical demand, consumer energy cost savings, and reduced CO{sub 2} emissions from retrofitting the space heating, space cooling, and water heating systems in existing U.S. single-family homes with state-of-the-art GHP systems. The investment for retrofitting typical U.S. single-family homes with state-of-the-art GHP systems is also analyzed using the metrics of net present value and levelized cost.

  1. Time-dependent barrier passage of two-dimensional non-Ohmic damping system.

    PubMed

    Wang, Chun-Yang

    2009-08-01

    The time-dependent barrier passage of two-dimensional non-Ohmic damping system is studied in the framework of statistical Langevin reactive dynamics. The stationary transmission coefficient is found to be a nonmonotonic function of the exponent delta which reveals an intrinsic effect of the friction's non-Markovian character on the two-dimensional reactive process; the coupling between nonreactive and reactive modes results in an optimal path for the reactant in all cases of non-Ohmic friction. A big net flux resulted from the less barrier recrossing behavior in the two-dimensional non-Ohmic friction case. PMID:19673571

  2. Rectification of swimming bacteria and self-driven particle systems by arrays of asymmetric barriers.

    PubMed

    Wan, M B; Olson Reichhardt, C J; Nussinov, Z; Reichhardt, C

    2008-07-01

    We show that the recent experimental observation of the rectification of swimming bacteria in a system with an array of asymmetric barriers occurs due to the ballistic component of the bacteria trajectories introduced by the bacterial "motor." Each bacterium selects a random direction for motion and then moves in this direction for a fixed period of time before randomly changing its orientation and moving in a new direction. In the limit where the bacteria undergo only Brownian motion on the size scale of the barriers, rectification does not occur. We examine the effects of steric interactions between the bacteria and observe a clogging effect upon increasing the bacteria density. PMID:18764155

  3. Assessment & Commitment Tracking System (ACTS)

    2004-12-20

    The ACTS computer code provides a centralized tool for planning and scheduling assessments, tracking and managing actions associated with assessments or that result from an event or condition, and "mining" data for reporting and analyzing information for improving performance. The ACTS application is designed to work with the MS SQL database management system. All database interfaces are written in SQL. The following software is used to develop and support the ACTS application: Cold Fusion HTMLmore » JavaScript Quest TOAD Microsoft Visual Source Safe (VSS) HTML Mailer for sending email Microsoft SQL Microsoft Internet Information Server« less

  4. Assessment & Commitment Tracking System (ACTS)

    SciTech Connect

    Bryant, Robert A.; Childs, Teresa A.; Miller, Michael A.; Sellars, Kevin J.

    2004-12-20

    The ACTS computer code provides a centralized tool for planning and scheduling assessments, tracking and managing actions associated with assessments or that result from an event or condition, and "mining" data for reporting and analyzing information for improving performance. The ACTS application is designed to work with the MS SQL database management system. All database interfaces are written in SQL. The following software is used to develop and support the ACTS application: Cold Fusion HTML JavaScript Quest TOAD Microsoft Visual Source Safe (VSS) HTML Mailer for sending email Microsoft SQL Microsoft Internet Information Server

  5. Thermal and Environmental Barrier Coating Development for Advanced Propulsion Engine Systems

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Miller, Robert A.; Fox, Dennis S.

    2008-01-01

    Ceramic thermal and environmental barrier coatings (TEBCs) are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments, and extend component lifetimes. Advanced TEBCs that have significantly lower thermal conductivity, better thermal stability and higher toughness than current coatings will be beneficial for future low emission and high performance propulsion engine systems. In this paper, ceramic coating design and testing considerations will be described for turbine engine high temperature and high-heat-flux applications. Thermal barrier coatings for metallic turbine airfoils and thermal/environmental barrier coatings for SiC/SiC ceramic matrix composite (CMC) components for future supersonic aircraft propulsion engines will be emphasized. Further coating capability and durability improvements for the engine hot-section component applications can be expected by utilizing advanced modeling and design tools.

  6. Reducing barriers to interoperability through collaborative development of standards for Earth science information systems

    NASA Astrophysics Data System (ADS)

    Percivall, G. S.; Arctur, D. K.

    2010-12-01

    Increasingly, Earth science research must make effective use of interdisciplinary data sources and processes. Non-interoperability impedes sharing of data and computing resources. Standards from the Open Geospatial Consortium (OGC) and other organizations are the basis for successfully deploying a seamless, distributed information infrastructure for the geosciences. Collaborative development of the standards has proven effective in reducing barriers to standards adoption. Standards are the basis for the success of the Internet and the World Wide Web. A standard describes a set of rules that have been agreed to in some consensus forum, such as the Internet Engineering Task Force (IETF), the International Organization for Standardization (ISO), or the OGC. As described in The Importance of Going Open, “non-interoperability causes organizations to spend much more than necessary on geospatial information technology development”. In the context of e-Science, the National Science Foundation’s Cyberinfrastructure Council argues that “The use of standards creates economies of scale and scope for developing and deploying common resources, tools, software, and services that enhance the use of cyberinfrastructure in multiple science and engineering communities.” Barriers to adoption include misperceptions and misuse of standards. “Adhering to standards costs more” - typically this statement is made when a research program considers implementing standards as a one-time modification to an existing system. Multiple economic studies have shown lower development costs when using standards over the life of a project. “Standards stifle innovation” - a key decision in research is to consider what assumptions to consider fixed and what to challenge. The long history of standards in research, e.g., SI units, is fundamental to assessing repeatable results by independent researchers. Similar need for common standards exist in the information systems used for Earth

  7. System facilitators and barriers to discussing older driver safety in primary care settings

    PubMed Central

    Betz, Marian E.; Jones, Jacqueline; Carr, David B.

    2015-01-01

    Background Primary care physicians play a leading role in counseling older drivers, but discussions often do not occur until safety concerns arise. Prior work suggests that routine questioning about driving might facilitate these difficult conversations. Objective To explore system-level factors affecting driving discussions in primary care settings, in order to inform the design and implementation of a program supporting routine conversations. Methods This qualitative descriptive study used iterative interviews with providers (physicians, nurses, medical assistants, social workers, and administrative staff) working at two clinics (one geriatric, one general internal medicine) at a tertiary-care teaching hospital. General inductive techniques in transcript analysis were used to identify stakeholder-perceived system-level barriers and facilitators to routine conversations with older drivers. Results From fifteen interviews, four themes emerged: (1) complexity of defined provider roles within primary care setting (which can both support team work and hamper efficiency); (2) inadequate resources to support providers (including clinical prompts, local guides, and access to social workers and driving specialists); (3) gaps in education of providers and patients about discussing driving; and (4) suggested models to enhance provider conversations with older drivers (including following successful examples and using defined pathways integrated into the electronic medical record). A fifth theme was that participants characterized their experiences in terms of current and ideal states. Conclusions Physicians have been tasked with assessing older driver safety and guiding older patients through the process of “driving retirement.” Attention to system-level factors such as provider roles, resources, and training can support them in this process. PMID:25617342

  8. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    PubMed Central

    Upadhyay, Ravi Kant

    2014-01-01

    Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods. PMID:25136634

  9. Drug delivery systems, CNS protection, and the blood brain barrier.

    PubMed

    Upadhyay, Ravi Kant

    2014-01-01

    Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.

  10. Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

    NASA Astrophysics Data System (ADS)

    Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

    In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

  11. OVERVIEW OF THE U.S. DEPARTMENT OF ENERGY AND NUCLEAR REGULATORY COMMISSION PERFORMANCE ASSESSMENT APPROACHES: CEMENTITIOUS BARRIERS PARTNERSHIP

    SciTech Connect

    Langton, C.; Burns, H.

    2009-05-29

    Engineered barriers including cementitious barriers are used at sites disposing or contaminated with low-level radioactive waste to enhance performance of the natural environment with respect to controlling the potential spread of contaminants. Drivers for using cementitious barriers include: high radionuclide inventory, radionuclide characteristics (e.g., long half-live, high mobility due to chemical form/speciation, waste matrix properties, shallow water table, and humid climate that provides water for leaching the waste). This document comprises the first in a series of reports being prepared for the Cementitious Barriers Partnership. The document is divided into two parts which provide a summary of: (1) existing experience in the assessment of performance of cementitious materials used for radioactive waste management and disposal and (2) sensitivity and uncertainty analysis approaches that have been applied for assessments. Each chapter is organized into five parts: Introduction, Regulatory Considerations, Specific Examples, Summary of Modeling Approaches and Conclusions and Needs. The objective of the report is to provide perspective on the state of the practice for conducting assessments for facilities involving cementitious barriers and to identify opportunities for improvements to the existing approaches. Examples are provided in two contexts: (1) performance assessments conducted for waste disposal facilities and (2) performance assessment-like analyses (e.g., risk assessments) conducted under other regulatory regimes. The introductory sections of each section provide a perspective on the purpose of performance assessments and different roles of cementitious materials for radioactive waste management. Significant experience with assessments of cementitious materials associated with radioactive waste disposal concepts exists in the US Department of Energy Complex and the commercial nuclear sector. Recently, the desire to close legacy facilities has created

  12. Toward an increased understanding of the barriers to colonic drug absorption in humans: implications for early controlled release candidate assessment.

    PubMed

    Tannergren, Christer; Bergendal, Anna; Lennernäs, Hans; Abrahamsson, Bertil

    2009-01-01

    The purpose of this study was to increase the understanding of in vivo colonic drug absorption in humans by summarizing and evaluating all regional in vivo human absorption data with focus on the interpretation of the colonic absorption data in relation to intestinal permeability and solubility. In addition, the usefulness of the Biopharmaceutics Classification System (BCS) in early assessment of the in vivo colonic absorption potential of controlled release drug candidates was investigated. Clinical regional absorption data (Cmax, Tmax, and AUC) of 42 drugs were collected from journal articles, abstracts, and internal reports, and the relative bioavailability in the colon (Frel(colon)) was obtained directly or calculated. Bioavailability, fraction dose absorbed, and information if the compounds were substrates for P-glycoprotein (P-gp) or cytochrome P450 3A (CYP3A) were also obtained. The BCS I drugs were well absorbed in the colon (Frel(colon) > 70%), although some drugs had lower values due to bacterial degradation in the colon. The low permeability drugs (BCS III/IV) had a lower degree of absorption in the colon (Frel(colon) < 50%). There was a clear correlation between in vitro Caco-2 permeability and Frel(colon), and atenolol and metoprolol may function as permeability markers for low and high colonic absorption, respectively. No obvious effect of P-gp on the colonic absorption of the drugs in this study was detected. There was insufficient data available to fully assess the impact of low solubility and slow dissolution rate. The estimated in vivo fractions dissolved of the only two compounds administered to the colon as both a solution and as solid particles were 55% and 92%, respectively. In conclusion, permeability and solubility are important barriers to colonic absorption in humans, and in vitro testing of these properties is recommended in early assessment of colonic absorption potential.

  13. Assessing Current and Future Performance of the Alamitos Gap Seawater Intrusion Barrier with a New Flow and Transport Model, Los Angeles and Orange Counties, CA

    NASA Astrophysics Data System (ADS)

    Sigda, J. M.; Deeds, N.; Jordan, D. L.; Sengebush, R.

    2010-12-01

    Seawater intrusion has threatened aquifers that supply Los Angeles residents since the 1920s, but now millions depend on effective resource management, especially for the four injection barriers. Even with ~6,000 acre-ft/yr injected through the Alamitos Gap barrier, which straddles the San Gabriel River, chloride concentrations have continued to increase in several aquifers inland of the barrier. On behalf of the Orange County Water District, the Water Replenishment District of Southern California, and the Los Angeles Department of Public Works, INTERA created a new flow and solute transport model for permitting, management, and performance assessment of the injection barrier. We devised a new conceptual model, water balance, geologic model, and numerical flow and solute transport models in five months to meet a regulatory deadline. Quickly developing a hydrogeologic framework was challenging because erosion and deposition on the uplifted transgression-regression system of aquitards and aquifers created pathways within the Gap for seawater to travel inland. The pathways, called mergence zones, connect the seawater-intruded Recent Aquifer with several of the deeper aquifers used for water supply. Capturing their locations and geometries was critical to effectively simulating past and future seawater intrusion. We extended the new hydrogeologic framework beyond and below previous frameworks by combining traditional geologic interpretation, GIS analysis, and an innovative geologic modeling software tool. Using the new conceptual and geologic models as a foundation, INTERA constructed a three-dimensional transient groundwater flow model, the Alamitos Barrier Flow Model (ABFM), using the MODFLOW 2000 code. The ABFM was calibrated in three ways: (1) a steady-state calibration to average heads for the 1999-2009 period, (2) transient calibration to the heads observed from 1999 through 2009, and (3) final flow calibration adjustments based on the chloride transport

  14. Emittance and absorptance of NASA ceramic thermal barrier coating system. [for turbine cooling

    NASA Technical Reports Server (NTRS)

    Liebert, C. H.

    1978-01-01

    Spectral emittance measurements were made on a two-layer ceramic thermal barrier coating system consisting of a metal substrate, a NiCrAly bond coating and a yttria-stabilized zirconia ceramic coating. Spectral emittance data were obtained for the coating system at temperatures of 300 to 1590 K, ceramic thickness of zero to 0.076 centimeter, and wavelengths of 0.4 to 14.6 micrometers. The data were transformed into total hemispherical emittance values and correlated with respect to ceramic coating thickness and temperature using multiple regression curve fitting techniques. The results show that the ceramic thermal barrier coating system is highly reflective and significantly reduces radiation heat loads on cooled gas turbine engine components. Calculation of the radiant heat transfer within the nonisothermal, translucent ceramic coating material shows that the gas-side ceramic coating surface temperature can be used in heat transfer analysis of radiation heat loads on the coating system.

  15. American Indian gay, bisexual and two-spirit men: a rapid assessment of HIV/AIDS risk factors, barriers to prevention and culturally-sensitive intervention.

    PubMed

    Burks, Derek J; Robbins, Rockey; Durtschi, Jayson P

    2011-03-01

    Epidemiological data indicate that HIV and AIDS are disproportionately affecting American Indians. Specific to American Indian men identifying as gay, bisexual, two-spirit or who have same-sex experiences, this study assessed HIV-risk behaviours and barriers to testing, prevention and treatment efforts. A rapid assessment model was utilised as an indigenous-supporting research design. Rigour and thoroughness were achieved via multiple validation procedures. Central themes surrounding barriers to HIV prevention included social discrimination, low self-esteem and substance use. Findings suggest the underutilisation of condoms due to ineffective placement and limited availability in popular locations among gay, bisexual and two-spirit individuals. Participants indicated that HIV testing is occurring less frequently and that testing was not available after hours or weekends. Barriers to treatment included a mistrust of the current healthcare system, a perceived lack of support from the Indian Health Service for AIDS care and a lack of transportation to healthcare appointments. Lastly, participants discussed and supported culturally-sensitive treatment services. This study calls attention to the value of an American Indian-specific HIV/AIDS service organisation, the presence of indigenous service providers in the community and culturally-sensitive healthcare providers. PMID:21049311

  16. 77 FR 14032 - John H. Chafee Coastal Barrier Resources System; Lee County, FL, and Newport County, RI...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... Fish and Wildlife Service John H. Chafee Coastal Barrier Resources System; Lee County, FL, and Newport... Service (Service), announce the availability of two John H. Chafee Coastal Barrier Resources System (CBRS... located in Newport County, Rhode Island. DATES: To ensure consideration, we must receive your...

  17. Quantitative risk assessment system (QRAS)

    NASA Technical Reports Server (NTRS)

    Weinstock, Robert M (Inventor); Smidts, Carol S (Inventor); Mosleh, Ali (Inventor); Chang, Yung-Hsien (Inventor); Swaminathan, Sankaran (Inventor); Groen, Francisco J (Inventor); Tan, Zhibin (Inventor)

    2001-01-01

    A quantitative risk assessment system (QRAS) builds a risk model of a system for which risk of failure is being assessed, then analyzes the risk of the system corresponding to the risk model. The QRAS performs sensitivity analysis of the risk model by altering fundamental components and quantifications built into the risk model, then re-analyzes the risk of the system using the modifications. More particularly, the risk model is built by building a hierarchy, creating a mission timeline, quantifying failure modes, and building/editing event sequence diagrams. Multiplicities, dependencies, and redundancies of the system are included in the risk model. For analysis runs, a fixed baseline is first constructed and stored. This baseline contains the lowest level scenarios, preserved in event tree structure. The analysis runs, at any level of the hierarchy and below, access this baseline for risk quantitative computation as well as ranking of particular risks. A standalone Tool Box capability exists, allowing the user to store application programs within QRAS.

  18. LONG-TERM PERFORMANCE ASSESSMENT OF PERMEABLE REACTIVE BARRIERS TO REMEDIATE CONTAMINATED GROUND WATER

    EPA Science Inventory

    Permeable reactive barriers (PRBs) are an emerging, alternative in-situ approach for remediating groundwater contamination that combine subsurface fluid flow management with a passive chemical treatment zone. The few pilot and commercial installations which have been implemented ...

  19. Performance Assessment of a Permeable Reactive Barrier for Ground Water Remediation Fifteen Years After Installation

    EPA Science Inventory

    The fifteen-year performance of a granular iron, permeable reactive barrier (PRB; Elizabeth City, North Carolina) is reviewed with respect to contaminanttreatment (hexavalent chromium and trichloroethylene) and hydraulic performance. Due to in-situ treatment of the chromium sourc...

  20. Communication barriers for deaf employees: Needs assessment and problem-solving strategies.

    PubMed

    Luft, Pamela

    2000-01-01

    Deaf people experience higher rates of unemployment and underemployment and earn lifetime wages that are between $356,000 and $609,000 less than their comparably educated normally hearing counterparts. This results in a substantial loss of earning power and career identity for members of this underutilized population of workers. This article examines how communication difficulties pose a major barrier to employment retention and advancement for deaf employees. These barriers exist (a) within the employee in terms of nonfluent use of English and reliance upon American Sign Language, (b) with the employment site, and (c) with agency service personnel. Primarily, these barriers reflect a lack of understanding of the cultural and communication needs of deaf people. Strategies to ameliorate these barriers include a model of long-term employment support using an ecological framework. PMID:12441540

  1. Run-up parameterization and beach vulnerability assessment on a barrier island: a downscaling approach

    NASA Astrophysics Data System (ADS)

    Medellín, G.; Brinkkemper, J. A.; Torres-Freyermuth, A.; Appendini, C. M.; Mendoza, E. T.; Salles, P.

    2016-01-01

    We present a downscaling approach for the study of wave-induced extreme water levels at a location on a barrier island in Yucatán (Mexico). Wave information from a 30-year wave hindcast is validated with in situ measurements at 8 m water depth. The maximum dissimilarity algorithm is employed for the selection of 600 representative cases, encompassing different combinations of wave characteristics and tidal level. The selected cases are propagated from 8 m water depth to the shore using the coupling of a third-generation wave model and a phase-resolving non-hydrostatic nonlinear shallow-water equation model. Extreme wave run-up, R2%, is estimated for the simulated cases and can be further employed to reconstruct the 30-year time series using an interpolation algorithm. Downscaling results show run-up saturation during more energetic wave conditions and modulation owing to tides. The latter suggests that the R2% can be parameterized using a hyperbolic-like formulation with dependency on both wave height and tidal level. The new parametric formulation is in agreement with the downscaling results (r2 = 0.78), allowing a fast calculation of wave-induced extreme water levels at this location. Finally, an assessment of beach vulnerability to wave-induced extreme water levels is conducted at the study area by employing the two approaches (reconstruction/parameterization) and a storm impact scale. The 30-year extreme water level hindcast allows the calculation of beach vulnerability as a function of return periods. It is shown that the downscaling-derived parameterization provides reasonable results as compared with the numerical approach. This methodology can be extended to other locations and can be further improved by incorporating the storm surge contributions to the extreme water level.

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

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

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

  3. Corral Monitoring System assessment results

    SciTech Connect

    Filby, E.E.; Haskel, K.J.

    1998-03-01

    This report describes the results of a functional and operational assessment of the Corral Monitoring Systems (CMS), which was designed to detect and document accountable items entering or leaving a monitored site. Its development was motivated by the possibility that multiple sites in the nuclear weapons states of the former Soviet Union might be opened to such monitoring under the provisions of the Strategic Arms Reduction Treaty. The assessment was performed at three levels. One level evaluated how well the planned approach addressed the target application, and which involved tracking sensitive items moving into and around a site being monitored as part of an international treaty or other agreement. The second level examined the overall design and development approach, while the third focused on individual subsystems within the total package. Unfortunately, the system was delivered as disassembled parts and pieces, with very poor documentation. Thus, the assessment was based on fragmentary operating data coupled with an analysis of what documents were provided with the system. The system design seemed to be a reasonable match to the requirements of the target application; however, important questions about site manning and top level administrative control were left unanswered. Four weaknesses in the overall design and development approach were detected: (1) poor configuration control and management, (2) inadequate adherence to a well defined architectural standard, (3) no apparent provision for improving top level error tolerance, and (4) weaknesses in the object oriented programming approach. The individual subsystems were found to offer few features or capabilities that were new or unique, even at the conceptual level. The CMS might possibly have offered a unique combination of features, but this level of integration was never realized, and it had no unique capabilities that could be readily extracted for use in another system.

  4. An evaluation of the fire barrier system thermo-lag 330-1

    SciTech Connect

    Nowlen, S.P.; Ross, S.

    1994-09-01

    This report presents the results of three fire endurance tests and one ampacity derating test set of the fire barrier system Thermo-Lag 330-1 Subliming Coating. Each test was performed using cable tray specimens protected by a nominal three-hour fire barrier envelope comprised of two layers of nominal 1/2 inch thick material. The fire barrier systems for two of the three fire endurance test articles and for the ampacity derating test article were installed in accordance with the manufacturer`s installations procedures. The barrier system for the third fire endurance test article was a full reproduction of one of the original manufacturer`s qualification test articles. This final test article included certain installation enhancements not considered typical of current nuclear power plant installations. The primary criteria for fire endurance performance evaluation was based on cable circuit integrity testing. Secondary consideration was also given to the temperature rise limits set forth in the ASTM E119 standard fire barrier test procedure. All three of the fire endurance specimens failed prematurely. Circuit integrity failures for the two fire endurance test articles with procedures-based installations were recorded at approximately 76 and 59 minutes into the exposures for a 6 inch wide and 12 inch wide cable tray respectively. Temperature excursion failures (single point) for these two test articles were noted at approximately 65 and 56 minutes respectively. The first circuit integrity failure for the full reproduction test article was recorded approximately 119 minutes into the exposure, and the first temperature excursion failure for this test article was recorded approximately 110 minutes into the exposure.

  5. Advanced thermal barrier system bond coatings for use on nickel-, cobalt- and iron-base alloy substrates

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1986-01-01

    New and improved Ni-, Co-, and Fe-base bond coatings have been identified for the ZrO2-Y2O3 thermal barrier coatings to be used on Ni-, Co-, and Fe-base alloy substrates. These bond coatings were evaluated in a cyclic furnace between 1120 and 1175 C. It was found that MCrAlYb (where M = Ni, Co, or Fe) bond coating thermal barrier systems have significantly longer lives than MCrAlY bond coating thermal barrier systems. The longest life was obtained with the FeCrAlYb thermal barrier system followed by NiCrAlYb and CoCrAlYb thermal barrier systems in that order.

  6. Reducing Barriers To The Use of High-Efficiency Lighting Systems

    SciTech Connect

    Peter Morante

    2005-12-31

    With funding from the U.S. Department of Energy (DOE), the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute completed the four-year research project, Reducing Barriers to the Use of High-Efficiency Lighting Systems. The initial objectives were: (1) identifying barriers to widespread penetration of lighting controls in commercial/industrial (C/I) applications that employ fluorescent lamp technologies, and (2) making recommendations to overcome these barriers. The addition of a fourth year expanded the original project objectives to include an examination of the impact on fluorescent lamps from dimming utilizing different lamp electrode heating and dimming ratios. The scope of the project was narrowed to identify barriers to the penetration of lighting controls into commercial-industrial (C/I) applications that employ fluorescent lamp technologies, and to recommend means for overcoming these barriers. Working with lighting manufacturers, specifiers, and installers, the project identified technological and marketing barriers to the widespread use of lighting controls, specifically automatic-off controls, occupancy sensors, photosensors, dimming systems, communication protocols and load-shedding ballasts. The primary barriers identified include cost effectiveness of lighting controls to the building owner, lack of standard communication protocols to allow different part of the control system to communicate effectively, and installation and commissioning issues. Overcoming the identified barriers requires lighting control products on the market to achieve three main goals: (1) Achieve sufficient functionality to meet the key requirements of their main market. (2) Allow significant cost reduction compared to current market standard systems. Cost should consider: hardware capital cost including wiring, design time required by the specifier and the control system manufacturer, installation time required by the electrician, and commissioning time and

  7. Political benefits as barriers to assessment of environmental costs in Brazil's Amazonian development planning: The example of the Jatapu Dam in Roraima

    NASA Astrophysics Data System (ADS)

    Fearnside, Philip M.; Barbosa, Reinaldo Imbrozio

    1996-09-01

    Development projects are rapidly changing the landscape in Brazilian Amazonia. Environmental impact assessments have been required since 1986, and the regulatory system is evolving as precedents are set by each new development project. The Jatapu Dam in Roraima provides an illustration of underlying impediments to assessment of environmental costs and to due consideration being given to these assessments when decisions are made. The high priority placed on the dam by the Roraima state government is unexplainable in terms of economic returns. The place of the dam in a long-term political strategy provides the best of several possible explanations, any one of which is incompatible with a “rational” weighing of economic and environmental costs and benefits. A number of lessons can be drawn from the experience of Jatapu, but some of the problems have no solution. The barriers to rational decision making illustrated by Jatapu apply to development projects in many parts of the world.

  8. Advanced Land Imager Assessment System

    NASA Technical Reports Server (NTRS)

    Chander, Gyanesh; Choate, Mike; Christopherson, Jon; Hollaren, Doug; Morfitt, Ron; Nelson, Jim; Nelson, Shar; Storey, James; Helder, Dennis; Ruggles, Tim; Kaita, Ed; Levy, Raviv; Ong, Lawrence; Markham, Brian; Schweiss, Robert

    2008-01-01

    The Advanced Land Imager Assessment System (ALIAS) supports radiometric and geometric image processing for the Advanced Land Imager (ALI) instrument onboard NASA s Earth Observing-1 (EO-1) satellite. ALIAS consists of two processing subsystems for radiometric and geometric processing of the ALI s multispectral imagery. The radiometric processing subsystem characterizes and corrects, where possible, radiometric qualities including: coherent, impulse; and random noise; signal-to-noise ratios (SNRs); detector operability; gain; bias; saturation levels; striping and banding; and the stability of detector performance. The geometric processing subsystem and analysis capabilities support sensor alignment calibrations, sensor chip assembly (SCA)-to-SCA alignments and band-to-band alignment; and perform geodetic accuracy assessments, modulation transfer function (MTF) characterizations, and image-to-image characterizations. ALIAS also characterizes and corrects band-toband registration, and performs systematic precision and terrain correction of ALI images. This system can geometrically correct, and automatically mosaic, the SCA image strips into a seamless, map-projected image. This system provides a large database, which enables bulk trending for all ALI image data and significant instrument telemetry. Bulk trending consists of two functions: Housekeeping Processing and Bulk Radiometric Processing. The Housekeeping function pulls telemetry and temperature information from the instrument housekeeping files and writes this information to a database for trending. The Bulk Radiometric Processing function writes statistical information from the dark data acquired before and after the Earth imagery and the lamp data to the database for trending. This allows for multi-scene statistical analyses.

  9. Quantitative assessment of the permeability of the rat blood-retinal barrier to small water-soluble non-electrolytes.

    PubMed

    Lightman, S L; Palestine, A G; Rapoport, S I; Rechthand, E

    1987-08-01

    1. The passive permeability of the blood-retinal barrier (b.r.b.) to the water-soluble non-electrolytes, sucrose and mannitol, was determined using a multiple time point-graphical approach as has been used in the assessment of blood-brain barrier (b.b.b.) permeability. 2. The calculated permeability surface area product for the b.r.b. for sucrose was 0.44 (+/- 0.081 S.E. of mean) X 10(-5) ml g-1 s-1 (n = 20) and for mannitol was 1.25 (+/- 0.30) X 10(-5) ml g-1 s-1 (n = 18). These values are similar and comparable to those found for the capillaries in the brain (P greater than 0.05) and significantly different from zero (P less than 0.01). 3. Data on the concentrations of sucrose in different parts of the eye show that the permeability of the blood-retinal barrier, rather than the more permeable blood-aqueous barrier permeability, was being measured by our technique. PMID:3119820

  10. Size effects in electronic and breakdown processes during barrier electric discharge in disperse systems

    NASA Astrophysics Data System (ADS)

    Aliev, M. M.; Zelenkova, E. A.

    2009-05-01

    The differences in the breakdown characteristics of barrier electric discharge (BED) in air and disperse systems (air + ZrO2) at 77 and 300 K are determined by polarization, plasma-forming medium charge deposition on the ZrO2 surface, and surface effects on the duration and mechanism of electron avalanches changing with the sizes of air voids between oxide surfaces ( E/ P ˜ const, T ˜ const).

  11. Sub-Barrier Fusion Calculations for the {sup 9}Li+{sup 70}Zn System

    SciTech Connect

    Balantekin, A. B.; Kocak, G.

    2008-11-11

    Sub-barrier fusion cross sections for the {sup 9}Li+{sup 70}Zn system are analyzed within the framework of the coupled channels model. We find that inclusion of the inelastic and one-neutron transfer channels in the coupled-channels calculations fails to reproduce the data. We find that possible formation of a molecular bond accompanied by two-neutron transfer may account for the observed behavior.

  12. Elucidating the role of aromatic interactions in rotational barriers involving aromatic systems.

    PubMed

    Lima, Carlos F R A C; Gomes, Lígia R; Low, John N; Silva, Artur M S; Santos, Luís M N B F

    2012-11-16

    The measurement of aryl-naphthyl rotational barriers, ΔG(⧧), in various solvents for two substituted 1,8-diarylnaphthalenes by dynamic (1)H NMR showed that ΔG(‡) trends in aromatic systems can be fully rationalized only when considering the different types of aromatic interactions that can be established in the ground and transition states, namely, intramolecular interactions involving the aromatic rings and specific solvation interactions. PMID:23106141

  13. Assessing the additive risks of PSII herbicide exposure to the Great Barrier Reef.

    PubMed

    Lewis, Stephen E; Schaffelke, Britta; Shaw, Melanie; Bainbridge, Zoë T; Rohde, Ken W; Kennedy, Karen; Davis, Aaron M; Masters, Bronwyn L; Devlin, Michelle J; Mueller, Jochen F; Brodie, Jon E

    2012-01-01

    Herbicide residues have been measured in the Great Barrier Reef lagoon at concentrations which have the potential to harm marine plant communities. Monitoring on the Great Barrier Reef lagoon following wet season discharge show that 80% of the time when herbicides are detected, more than one are present. These herbicides have been shown to act in an additive manner with regards to photosystem-II inhibition. In this study, the area of the Great Barrier Reef considered to be at risk from herbicides is compared when exposures are considered for each herbicide individually and also for herbicide mixtures. Two normalisation indices for herbicide mixtures were calculated based on current guidelines and PSII inhibition thresholds. The results show that the area of risk for most regions is greatly increased under the proposed additive PSII inhibition threshold and that the resilience of this important ecosystem could be reduced by exposure to these herbicides.

  14. CAIS. Condition Assessment Information System

    SciTech Connect

    Oak, J.C.

    1996-09-30

    CAIS is used by Architects and Engineers to gather facility condition assessment data. This data consist of architectural, civil, structural, electrical, and mechanical systems and components that are a part of the inspected facility. Data is collected using a hand-held, pen-based computer system which is preprogrammed for detailed inventories of individual components. The program is deficiency based for collecting data for repair and replacement observations. Observations are recorded on checklists preformatted to individual site needs, allowing for comments on unusual conditions to be documented on site. Data is transferred to a central database, where it can be reviewed, costed, and reported on using different scenarios. Information can be transferred to the DOE operations offices as well as to the DOE FIMS database for each site.

  15. Chronic systemic IL-1β exacerbates central neuroinflammation independently of the blood-brain barrier integrity.

    PubMed

    Murta, Verónica; Farías, María Isabel; Pitossi, Fernando Juan; Ferrari, Carina Cintia

    2015-01-15

    Peripheral circulating cytokines are involved in immune to brain communication and systemic inflammation is considered a risk factor for flaring up the symptoms in most neurodegenerative diseases. We induced both central inflammatory demyelinating lesion, and systemic inflammation with an interleukin-1β expressing adenovector. The peripheral pro-inflammatory stimulus aggravated the ongoing central lesion independently of the blood-brain barrier (BBB) integrity. This model allows studying the role of specific molecules and cells (neutrophils) from the innate immune system, in the relationship between central and peripheral communication, and on relapsing episodes of demyelinating lesions, along with the role of BBB integrity.

  16. Launcher Systems Development Cost: Behavior, Uncertainty, Influences, Barriers and Strategies for Reduction

    NASA Technical Reports Server (NTRS)

    Shaw, Eric J.

    2001-01-01

    This paper will report on the activities of the IAA Launcher Systems Economics Working Group in preparations for its Launcher Systems Development Cost Behavior Study. The Study goals include: improve launcher system and other space system parametric cost analysis accuracy; improve launcher system and other space system cost analysis credibility; and provide launcher system and technology development program managers and other decisionmakers with useful information on development cost impacts of their decisions. The Working Group plans to explore at least the following five areas in the Study: define and explain development cost behavior terms and concepts for use in the Study; identify and quantify sources of development cost and cost estimating uncertainty; identify and quantify significant influences on development cost behavior; identify common barriers to development cost understanding and reduction; and recommend practical, realistic strategies to accomplish reductions in launcher system development cost.

  17. Systemic Hemin Therapy Attenuates Blood-Brain Barrier Disruption after Intracerebral Hemorrhage

    PubMed Central

    Lu, Xiangping; Chen-Roetling, Jing; Regan, Raymond F.

    2014-01-01

    Injury to the blood-brain barrier (BBB) is a key feature of intracerebral hemorrhage (ICH) and may contribute to perihematomal cell injury. Pretreatment with the heme oxygenase (HO)-1 inducer hemin improves barrier function and neurological outcome in experimental models of traumatic and ischemic CNS injury. Since hemin is already in clinical use to treat acute porphyrias, this translational study was designed to test its effect on BBB function when initiated after ICH in two mouse models. At a dose similar to those used in most preconditioning studies (26 mg/kg i.p.), post-hemorrhage treatment with hemin reduced parenchymal extravasation of Evans blue by about three-quarters in both the blood injection and collagenase ICH models. Similar efficacy was observed when treatment was begun at one or three hours. At the lower dose that is currently in clinical use (4 mg/kg beginning at 3 hours), hemin also improved barrier function in both models, as assessed by both Evans blue and FITC-dextran leakage; however, it was somewhat less potent, reducing Evans blue leakage by about half. This dose was nevertheless sufficient to attenuate striatal cell loss and accelerate neurological recovery. Consistent with prior observations, striatal HO-1 expression was increased by hemin, and was localized to perivascular cells. These results suggest that hemin may be an effective therapy for ICH with a clinically relevant time window. Further study of the repurposing of this old drug seems warranted. PMID:24952361

  18. Mobile munitions assessment system development

    SciTech Connect

    Rowe, L.C.; Watts, K.D.; Jorgensen, C.L.

    1996-05-01

    The United States has been involved in the development, testing, storage and disposal of chemical weapons since World War I. As a result, there are numerous sites which contain the presence of chemical warfare materiel. This materiel is in the form of buried surplus munitions, munitions that did not detonate during testing and other forms. These items pose a significant human health and environmental hazard and must be disposed of properly. The US Army was tasked by the Department of Defense with the remediation of all non-stockpile chemical warfare materiel. To help comply with this tasking, the Army Project Manager for Nonstockpile Chemical Materiel is sponsoring the development of a Mobile Munitions Assessment System (MMAS). The system is being developed by the Idaho National Engineering Laboratory and Dugway Proving Ground. The purpose of the system is to inspect suspect munitions and containers, identify the fill, evaluate the fuzing and firing train and analyze samples from the surrounding area to determine if chemical warfare materiel is present. The information gained from the application of the MMAS and other systems is intended to be used to establish the best method to handle and dispose of a given munition and its contents.

  19. Oxidation and degradation of a plasma-sprayed thermal barrier coating system

    SciTech Connect

    Haynes, J.A.; Ferber, M.K.; Porter, W.D.

    1996-04-01

    The isothermal oxidation behavior of thermal barrier coating (TBC) specimens consisting of single-crystal superalloy substrates, vacuum plasma-sprayed Ni-22Cr-10Al-1Y bond coatings and air plasma-sprayed 7.5 wt.% yttria stabilized zirconia top coatings was evaluated by thermogravimetric analysis at 1150{degrees}C for up to 200 hours. Coating durability was assessed by furnace cycling at 1150{degrees}C. Coatings and reaction products were identified by x-ray diffraction, field-emission scanning electron microscopy and energy dispersive spectroscopy.

  20. Nanoparticles and blood-brain barrier: the key to central nervous system diseases.

    PubMed

    Domínguez, Alazne; Suárez-Merino, Blanca; Goñi-de-Cerio, Felipe

    2014-01-01

    Major central nervous system disorders represent a significant and worldwide public health problem. In fact, the therapeutic success of many pharmaceuticals developed to treat central nervous system diseases is still moderate, since the blood-brain barrier (BBB) limits the access of systemically administered compounds to the brain. Therefore, they require the application of a large total dose of a drug, and cause numerous toxic effects. The development of nanotechnological systems are useful tools to deliver therapeutics and/or diagnostic probes to the brain due to nanocarriers having the potential to improve the therapeutic effect of drugs and to reduce their side effects. This review provides a brief overview of the variety of carriers employed for central nervous system drug and diagnostic probes delivery. Further, this paper focuses on the novel nanocarriers developed to enhance brain delivery across the blood-brain barrier. Special attention is paid to liposomes, micelles, polymeric and lipid-based nanoparticles, dendrimers and carbon nanotubes. The recent developments in nanocarrier implementation through size/charge optimization and surface modifications (PEGylation, targeting delivery, and coating with surfactants) have been discussed. And a detailed description of the nanoscaled pharmaceutical delivery devices employed for the treatment of central nervous system disorders have also been defined. The aim of the review is to evaluate the nanotechnology-based drug delivery strategies to treat different central nervous system disorders.

  1. Influences of specific ions in groundwater on concrete degradation in subsurface engineered barrier system.

    PubMed

    Lin, Wen-Sheng; Liu, Chen-Wuing; Li, Ming-Hsu

    2016-01-01

    Many disposal concepts currently show that concrete is an effective confinement material used in engineered barrier systems (EBS) at a number of low-level radioactive waste (LLW) disposal sites. Cement-based materials have properties for the encapsulation, isolation, or retardation of a variety of hazardous contaminants. The reactive chemical transport model of HYDROGEOCHEM 5.0 was applied to simulate the effect of hydrogeochemical processes on concrete barrier degradation in an EBS which has been proposed to use in the LLW disposal site in Taiwan. The simulated results indicated that the main processes that are responsible for concrete degradation are the species induced from hydrogen ion, sulfate, and chloride. The EBS with the side ditch drainage system effectively discharges the infiltrated water and lowers the solute concentrations that may induce concrete degradation. The redox processes markedly influence the formations of the degradation materials. The reductive environment in the EBS reduces the formation of ettringite in concrete degradation processes. Moreover, the chemical conditions in the concrete barriers maintain an alkaline condition after 300 years in the proposed LLW repository. This study provides a detailed picture of the long-term evolution of the hydrogeochemical environment in the proposed LLW disposal site in Taiwan. PMID:27376013

  2. Influences of specific ions in groundwater on concrete degradation in subsurface engineered barrier system.

    PubMed

    Lin, Wen-Sheng; Liu, Chen-Wuing; Li, Ming-Hsu

    2016-01-01

    Many disposal concepts currently show that concrete is an effective confinement material used in engineered barrier systems (EBS) at a number of low-level radioactive waste (LLW) disposal sites. Cement-based materials have properties for the encapsulation, isolation, or retardation of a variety of hazardous contaminants. The reactive chemical transport model of HYDROGEOCHEM 5.0 was applied to simulate the effect of hydrogeochemical processes on concrete barrier degradation in an EBS which has been proposed to use in the LLW disposal site in Taiwan. The simulated results indicated that the main processes that are responsible for concrete degradation are the species induced from hydrogen ion, sulfate, and chloride. The EBS with the side ditch drainage system effectively discharges the infiltrated water and lowers the solute concentrations that may induce concrete degradation. The redox processes markedly influence the formations of the degradation materials. The reductive environment in the EBS reduces the formation of ettringite in concrete degradation processes. Moreover, the chemical conditions in the concrete barriers maintain an alkaline condition after 300 years in the proposed LLW repository. This study provides a detailed picture of the long-term evolution of the hydrogeochemical environment in the proposed LLW disposal site in Taiwan.

  3. Effects of sea-level rise on barrier island groundwater system dynamics: ecohydrological implications

    USGS Publications Warehouse

    Masterson, John P.; Fienen, Michael N.; Thieler, E. Robert; Gesch, Dean B.; Gutierrez, Benjamin T.; Plant, Nathaniel G.

    2014-01-01

    We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater response to island morphology by evaluating changes at three sites. This interdependence can have a profound effect on ecosystem composition in these fragile coastal landscapes under long-term changing climatic conditions.

  4. A systems engineering approach to technology assessment.

    PubMed

    Crepea, A T

    1995-01-01

    This paper presents a technology assessment process based on systems engineering methodologies used in the aerospace and defense industries. Systems engineering, defined in the U.S. military manual for engineering management, is a logical sequence of activities and decisions transforming an operational need into a description of system performance parameters and a preferred system configuration. Like systems engineering, technology assessment is driven by a single, clear need. The objective of systems engineering is to design a new system configuration; technology assessment assesses existing technologies to address this need. A six-step technology assessment model based on systems engineering principles is presented, including: (1) needs assessment; (2) clinical feasibility analysis; (3) systems assessment; (4) approval; (5) implementation; and (6) follow-up/CQI. PMID:10144457

  5. Industrial energy systems and assessment opportunities

    NASA Astrophysics Data System (ADS)

    Barringer, Frank Leonard, III

    Industrial energy assessments are performed primarily to increase energy system efficiency and reduce energy costs in industrial facilities. The most common energy systems are lighting, compressed air, steam, process heating, HVAC, pumping, and fan systems, and these systems are described in this document. ASME has produced energy assessment standards for four energy systems, and these systems include compressed air, steam, process heating, and pumping systems. ASHRAE has produced an energy assessment standard for HVAC systems. Software tools for energy systems were developed for the DOE, and there are software tools for almost all of the most common energy systems. The software tools are AIRMaster+ and LogTool for compressed air systems, SSAT and 3E Plus for steam systems, PHAST and 3E Plus for process heating systems, eQUEST for HVAC systems, PSAT for pumping systems, and FSAT for fan systems. The recommended assessment procedures described in this thesis are used to set up an energy assessment for an industrial facility, collect energy system data, and analyze the energy system data. The assessment recommendations (ARs) are opportunities to increase efficiency and reduce energy consumption for energy systems. A set of recommended assessment procedures and recommended assessment opportunities are presented for each of the most common energy systems. There are many assessment opportunities for industrial facilities, and this thesis describes forty-three ARs for the seven different energy systems. There are seven ARs for lighting systems, ten ARs for compressed air systems, eight ARs for boiler and steam systems, four ARs for process heating systems, six ARs for HVAC systems, and four ARs for both pumping and fan systems. Based on a history of past assessments, average potential energy savings and typical implementation costs are shared in this thesis for most ARs. Implementing these ARs will increase efficiency and reduce energy consumption for energy systems in

  6. Critical infrastructure systems of systems assessment methodology.

    SciTech Connect

    Sholander, Peter E.; Darby, John L.; Phelan, James M.; Smith, Bryan; Wyss, Gregory Dane; Walter, Andrew; Varnado, G. Bruce; Depoy, Jennifer Mae

    2006-10-01

    Assessing the risk of malevolent attacks against large-scale critical infrastructures requires modifications to existing methodologies that separately consider physical security and cyber security. This research has developed a risk assessment methodology that explicitly accounts for both physical and cyber security, while preserving the traditional security paradigm of detect, delay, and respond. This methodology also accounts for the condition that a facility may be able to recover from or mitigate the impact of a successful attack before serious consequences occur. The methodology uses evidence-based techniques (which are a generalization of probability theory) to evaluate the security posture of the cyber protection systems. Cyber threats are compared against cyber security posture using a category-based approach nested within a path-based analysis to determine the most vulnerable cyber attack path. The methodology summarizes the impact of a blended cyber/physical adversary attack in a conditional risk estimate where the consequence term is scaled by a ''willingness to pay'' avoidance approach.

  7. Dynamical systems probabilistic risk assessment.

    SciTech Connect

    Denman, Matthew R.; Ames, Arlo Leroy

    2014-03-01

    Probabilistic Risk Assessment (PRA) is the primary tool used to risk-inform nuclear power regulatory and licensing activities. Risk-informed regulations are intended to reduce inherent conservatism in regulatory metrics (e.g., allowable operating conditions and technical specifications) which are built into the regulatory framework by quantifying both the total risk profile as well as the change in the risk profile caused by an event or action (e.g., in-service inspection procedures or power uprates). Dynamical Systems (DS) analysis has been used to understand unintended time-dependent feedbacks in both industrial and organizational settings. In dynamical systems analysis, feedback loops can be characterized and studied as a function of time to describe the changes to the reliability of plant Structures, Systems and Components (SSCs). While DS has been used in many subject areas, some even within the PRA community, it has not been applied toward creating long-time horizon, dynamic PRAs (with time scales ranging between days and decades depending upon the analysis). Understanding slowly developing dynamic effects, such as wear-out, on SSC reliabilities may be instrumental in ensuring a safely and reliably operating nuclear fleet. Improving the estimation of a plant's continuously changing risk profile will allow for more meaningful risk insights, greater stakeholder confidence in risk insights, and increased operational flexibility.

  8. Prezygotic barriers to hybridization in marine broadcast spawners: reproductive timing and mating system variation.

    PubMed

    Monteiro, Carla A; Serrão, Ester A; Pearson, Gareth A

    2012-01-01

    Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive isolation between the sibling brown algal species Fucus spiralis, Fucus guiryi (selfing hermaphrodite) and Fucus vesiculosus (dioecious) was studied because they form hybrids in parapatry in the rocky intertidal zone, maintain species integrity over a broad geographic range, and have contrasting mating systems. We compared reproductive synchrony (spawning overlap) between the three species at several temporal scales (yearly/seasonal, semilunar/tidal, and hourly during single tides). Interspecific patterns of egg release were coincident at seasonal (single peak in spring to early summer) to semilunar timescales. Synthesis of available data indicated that spawning is controlled by semidiurnal tidal and daily light-dark cues, and not directly by semilunar cycles. Importantly, interspecific shifts in timing detected at the hourly scale during single tides were consistent with a partial ecological prezygotic hybridization barrier. The species displayed patterns of gamete release consistent with a power law distribution, indicating a high degree of reproductive synchrony, while the hypothesis of weaker selective constraints for synchrony in selfing versus outcrossing species was supported by observed spawning in hermaphrodites over a broader range of tidal phase than in outcrossers. Synchronous gamete release is critical to the success of external fertilization, while high-energy intertidal environments may offer only limited windows of reproductive opportunity. Within these windows, however, subtle variations in reproductive timing have evolved with the potential to form ecological

  9. Prezygotic Barriers to Hybridization in Marine Broadcast Spawners: Reproductive Timing and Mating System Variation

    PubMed Central

    Monteiro, Carla A.; Serrão, Ester A.; Pearson, Gareth A.

    2012-01-01

    Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive isolation between the sibling brown algal species Fucus spiralis, Fucus guiryi (selfing hermaphrodite) and Fucus vesiculosus (dioecious) was studied because they form hybrids in parapatry in the rocky intertidal zone, maintain species integrity over a broad geographic range, and have contrasting mating systems. We compared reproductive synchrony (spawning overlap) between the three species at several temporal scales (yearly/seasonal, semilunar/tidal, and hourly during single tides). Interspecific patterns of egg release were coincident at seasonal (single peak in spring to early summer) to semilunar timescales. Synthesis of available data indicated that spawning is controlled by semidiurnal tidal and daily light-dark cues, and not directly by semilunar cycles. Importantly, interspecific shifts in timing detected at the hourly scale during single tides were consistent with a partial ecological prezygotic hybridization barrier. The species displayed patterns of gamete release consistent with a power law distribution, indicating a high degree of reproductive synchrony, while the hypothesis of weaker selective constraints for synchrony in selfing versus outcrossing species was supported by observed spawning in hermaphrodites over a broader range of tidal phase than in outcrossers. Synchronous gamete release is critical to the success of external fertilization, while high-energy intertidal environments may offer only limited windows of reproductive opportunity. Within these windows, however, subtle variations in reproductive timing have evolved with the potential to form ecological

  10. Regulatory barriers to equity in a health system in transition: a qualitative study in Bulgaria

    PubMed Central

    2011-01-01

    Background Health reforms in Bulgaria have introduced major changes to the financing, delivery and regulation of health care. As in many other countries of Central and Eastern Europe, these included introducing general practice, establishing a health insurance system, reorganizing hospital services, and setting up new payment mechanisms for providers, including patient co-payments. Our study explored perceptions of regulatory barriers to equity in Bulgarian child health services. Methods 50 qualitative in-depth interviews with users, providers and policy-makers concerned with child health services in Bulgaria, conducted in two villages, one town of 70,000 inhabitants, and the capital Sofia. Results The participants in our study reported a variety of regulatory barriers which undermined the principles of equity and, as far as the health insurance system is concerned, solidarity. These included non-participation in the compulsory health insurance system, informal payments, and charging user fees to exempted patients. The participants also reported seemingly unnecessary treatments in the growing private sector. These regulatory failures were associated with the fast pace of reforms, lack of consultation, inadequate public financing of the health system, a perceived "commercialization" of medicine, and weak enforcement of legislation. A recurrent theme from the interviews was the need for better information about patient rights and services covered by the health insurance system. Conclusions Regulatory barriers to equity and compliance in daily practice deserve more attention from policy-makers when embarking on health reforms. New financing sources and an increasing role of the private sector need to be accompanied by an appropriate and enforceable regulatory framework to control the behavior of health care providers and ensure equity in access to health services. PMID:21923930

  11. Trap Cropping Systems and a Physical Barrier for Suppression of Stink Bugs (Hemiptera: Pentatomidae) in Cotton.

    PubMed

    Tillman, P G; Khrimian, A; Cottrell, T E; Lou, X; Mizell, R F; Johnson, C J

    2015-10-01

    Euschistus servus (Say), Nezara viridula (L.), and Chinavia hilaris (Say) (Hemiptera: Pentatomidae) are economic pests of cotton in the coastal plain of the southeastern United States. The objective of this 2-yr study was to determine the ability of trap cropping systems, pheromone-baited stink bug traps, and a synthetic physical barrier at the peanut-to-cotton interface to manage stink bugs in cotton. The physical barrier was the most effective management tactic. Stink bug density in cotton was lowest for this treatment. In 2010, boll injury was lower for the physical barrier compared to the other treatments except for soybean with stink bug traps. In 2011, boll injury was lower for this treatment compared to the control. Soybean was an effective trap crop, reducing both stink bug density in cotton and boll injury regardless if used alone or in combination with either stink bug traps or buckwheat. Incorporation of buckwheat in soybean enhanced parasitism of E. servus egg masses by Telenomus podisi Ashmead in cotton. The insertion of eyelets in the lid of the insect-collecting device of a stink bug trap allowed adult stink bug parasitoids, but not E. servus, to escape. Stand-alone stink bug traps were not very effective in deterring colonization of cotton by stink bugs or reducing boll injury. The paucity of effective alternative control measures available for stink bug management justifies further full-scale evaluations into these management tactics for control of these pests in crops. PMID:26453721

  12. Investigating Barriers to Tuberculosis Evaluation in Uganda Using Geographic Information Systems.

    PubMed

    Ross, Jennifer M; Cattamanchi, Adithya; Miller, Cecily R; Tatem, Andrew J; Katamba, Achilles; Haguma, Priscilla; Handley, Margaret A; Davis, J Lucian

    2015-10-01

    Reducing geographic barriers to tuberculosis (TB) care is a priority in high-burden countries where patients frequently initiate, but do not complete, the multi-day TB evaluation process. Using routine cross-sectional study from six primary-health clinics in rural Uganda from 2009 to 2012, we explored whether geographic barriers affect completion of TB evaluation among adults with unexplained chronic cough. We measured distance from home parish to health center and calculated individual travel time using a geographic information systems technique incorporating roads, land cover, and slope, and measured its association with completion of TB evaluation. In 264,511 patient encounters, 4,640 adults (1.8%) had sputum smear microscopy ordered; 2,783 (60%) completed TB evaluation. Median travel time was 68 minutes for patients with TB examination ordered compared with 60 minutes without (P < 0.010). Travel time differed between those who did and did not complete TB evaluation at only one of six clinics, whereas distance to care did not differ at any of them. Neither distance nor travel time predicted completion of TB evaluation in rural Uganda, although limited detail in road and village maps restricted full implementation of these mapping techniques. Better data are needed on geographic barriers to access clinics offering TB services to improve TB diagnosis.

  13. Physicochemical properties of polymers: An important system to overcome the cell barriers in gene transfection.

    PubMed

    Namvar, Ali; Bolhassani, Azam; Khairkhah, Niloofardokht; Motevalli, Fatemeh

    2015-07-01

    Delivery of the macromolecules including DNA, miRNA, and antisense oligonucleotides is typically mediated by carriers due to the large size and negative charge. Different physical (e.g., gene gun or electroporation), and chemical (e.g., cationic polymer or lipid) vectors have been already used to improve the efficiency of gene transfer. Polymer-based DNA delivery systems have attracted special interest, in particular via intravenous injection with many intra- and extracellular barriers. The recent progress has shown that stimuli-responsive polymers entitled as multifunctional nucleic acid vehicles can act to target specific cells. These nonviral carriers are classified by the type of stimulus including reduction potential, pH, and temperature. Generally, the physicochemical characterization of DNA-polymer complexes is critical to enhance the transfection potency via protection of DNA from nuclease digestion, endosomal escape, and nuclear localization. The successful clinical applications will depend on an exact insight of barriers in gene delivery and development of carriers overcoming these barriers. Consequently, improvement of novel cationic polymers with low toxicity and effective for biomedical use has attracted a great attention in gene therapy. This article summarizes the main physicochemical and biological properties of polyplexes describing their gene transfection behavior, in vitro and in vivo. In this line, the relative efficiencies of various cationic polymers are compared.

  14. Interorganisational Integration: Healthcare Professionals’ Perspectives on Barriers and Facilitators within the Danish Healthcare System

    PubMed Central

    Godtfredsen, Nina Skavlan; Frølich, Anne

    2016-01-01

    Introduction: Despite many initiatives to improve coordination of patient pathways and intersectoral cooperation, Danish health care is still fragmented, lacking intra- and interorganisational integration. This study explores barriers to and facilitators of interorganisational integration as perceived by healthcare professionals caring for patients with chronic obstructive pulmonary disease within the Danish healthcare system. Methods: Seven focus groups were conducted in January through July 2014 with 21 informants from general practice, local healthcare centres and a pulmonary department at a university hospital in the Capital Region of Denmark. Results and discussion: Our results can be grouped into five influencing areas for interorganisational integration: communication/information transfer, committed leadership, patient engagement, the role and competencies of the general practitioner and organisational culture. Proposed solutions to barriers in each area hold the potential to improve care integration as experienced by individuals responsible for supporting and facilitating it. Barriers and facilitators to integrating care relate to clinical, professional, functional and normative integration. Especially, clinical, functional and normative integration seems fundamental to developing integrated care in practice from the perspective of healthcare professionals. PMID:27616948

  15. Investigating Barriers to Tuberculosis Evaluation in Uganda Using Geographic Information Systems.

    PubMed

    Ross, Jennifer M; Cattamanchi, Adithya; Miller, Cecily R; Tatem, Andrew J; Katamba, Achilles; Haguma, Priscilla; Handley, Margaret A; Davis, J Lucian

    2015-10-01

    Reducing geographic barriers to tuberculosis (TB) care is a priority in high-burden countries where patients frequently initiate, but do not complete, the multi-day TB evaluation process. Using routine cross-sectional study from six primary-health clinics in rural Uganda from 2009 to 2012, we explored whether geographic barriers affect completion of TB evaluation among adults with unexplained chronic cough. We measured distance from home parish to health center and calculated individual travel time using a geographic information systems technique incorporating roads, land cover, and slope, and measured its association with completion of TB evaluation. In 264,511 patient encounters, 4,640 adults (1.8%) had sputum smear microscopy ordered; 2,783 (60%) completed TB evaluation. Median travel time was 68 minutes for patients with TB examination ordered compared with 60 minutes without (P < 0.010). Travel time differed between those who did and did not complete TB evaluation at only one of six clinics, whereas distance to care did not differ at any of them. Neither distance nor travel time predicted completion of TB evaluation in rural Uganda, although limited detail in road and village maps restricted full implementation of these mapping techniques. Better data are needed on geographic barriers to access clinics offering TB services to improve TB diagnosis. PMID:26217044

  16. Patterns of physical activity among American Indian children: an assessment of barriers and support.

    PubMed

    Thompson, J L; Davis, S M; Gittelsohn, J; Going, S; Becenti, A; Metcalfe, L; Stone, E; Harnack, L; Ring, K

    2001-12-01

    Estimates indicate that 10% to 50% of American Indian and non-Indian children in the U.S. are obese, defined as a body mass index > or = 95th percentile of the NHANES II reference data. Pathways is a two-phase, multi-site study to develop and test a school-based obesity prevention program in American Indian schoolchildren in grades three through five. During Phase I feasibility prior to initiation of the Pathways trial, data were collected related to physical activity patterns, and the supports of, and barriers to, physical activity. Nine schools from communities representing six different tribal groups participated in this study. Multiple measures were used for data collection including direct observation, paired child interviews, and in-depth interviews and focus groups with adults. Students completed the self-administered Knowledge, Attitudes, and Behaviors (KAB) survey, and a Physical Activity Questionnaire (PAQ). Barriers to physical activity at schools included a lack of facilities, equipment, and trained staff persons for PE. Adults were not consistently active with their children, but they were highly supportive of their children's activity level. Children reported a strong enjoyment of physical activity and strong peer support to be physically active. Weather conditions, safety concerns, and homework/chores were common barriers to physical activity reported by children and adult caregivers. The information was used to design culturally and age-appropriate, practical interventions including the five physical activity programs for schoolchildren in the Pathways study.

  17. Marsh Edge Erosion Effects in Coupled Barrier Island-Marsh Systems

    NASA Astrophysics Data System (ADS)

    Lauzon, R.; Moore, L. J.; Murray, A. B.; Walters, D.; Fagherazzi, S.; Mariotti, G.

    2014-12-01

    While until recently marsh loss was largely thought to be due to an inability for vertical accretion rates to match rates of sea level rise, marsh edge erosion by wind waves is now thought to be the leading cause of marsh loss worldwide. To better understand the response of coastal ecosystems to future changes in sea level and storm intensity, we further develop the coupled barrier-island marsh evolution model GEOMBEST+. We use the relationship between wave height (and therefore energy) and fetch and wind speed to add marsh edge erosion to the model, as well as to provide a more physical formulation for bay bottom erosion. Previous research addressing marshes in isolation from barrier islands (Mariotti and Fagherazzi, 2013) suggests that the existence of a backbarrier marsh is an unstable state, tending to either grow laterally to completely fill an adjacent basin or to erode away completely. Previous results of GEOMBEST+ experiments (Walters et al., in review) suggest that couplings with an adjacent barrier island can add an additional alternate long-lasting state: a narrow marsh supported by sediment influx from overwash. Here we present the results of new GEOMBEST+ model experiments that address how the addition of lateral erosion by wind waves affects the existence and characteristics of the narrow marsh state. Specifically, we seek to address how the frequency and characteristic time and space scales of the narrow march state are affected. Model experiments also explore more broadly the importance of wind wave effects in understanding the coupled dynamics of marsh-barrier island systems.

  18. Asphalt emulsion radon barrier systems for uranium mill tailings: an overview of the technology

    SciTech Connect

    Baker, E.G.; Hartley, J.N.; Freeman, H.D.; Gates, T.E.; Nelson, D.A.; Dunning, R.L.

    1984-03-01

    Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field tested at Grand Junction, Colorado. Results from laboratory and field tests indicate that this system is effective in reducing radon release to near-background levels (<2.5 pCi m/sup -2/s/sup -1/) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and analysis indicates that asphalt emulsion covers are cost-competitive with other cover systems. This report summarizes the technology for asphalt emulsion radon barrier systems. 59 references, 45 figures, 36 tables.

  19. Integration of health into urban spatial planning through impact assessment: Identifying governance and policy barriers and facilitators

    SciTech Connect

    Carmichael, Laurence; Barton, Hugh; Gray, Selena; Lease, Helen; Pilkington, Paul

    2012-01-15

    This article presents the results of a review of literature examining the barriers and facilitators in integrating health in spatial planning at the local, mainly urban level, through appraisals. Our literature review covered the UK and non UK experiences of appraisals used to consider health issues in the planning process. We were able to identify four main categories of obstacles and facilitators including first the different knowledge and conceptual understanding of health by different actors/stakeholders, second the types of governance arrangements, in particular partnerships, in place and the political context, third the way institutions work, the responsibilities they have and their capacity and resources and fourth the timeliness, comprehensiveness and inclusiveness of the appraisal process. The findings allowed us to draw some lessons on the governance and policy framework regarding the integration of health impact into spatial planning, in particular considering the pros and cons of integrating health impact assessment (HIA) into other forms of impact assessment of spatial planning decisions such as environmental impact assessment (EIA) and strategic environment assessment (SEA). In addition, the research uncovered a gap in the literature that tends to focus on the mainly voluntary HIA to assess health outcomes of planning decisions and neglect the analysis of regulatory mechanisms such as EIA and SEA. - Highlights: Black-Right-Pointing-Pointer Governance and policy barriers and facilitators to the integration of health into urban planning. Black-Right-Pointing-Pointer Review of literature on impact assessment methods used across the world. Black-Right-Pointing-Pointer Knowledge, partnerships, management/resources and processes can impede integration. Black-Right-Pointing-Pointer HIA evaluations prevail uncovering research opportunities for evaluating other techniques.

  20. Universal tumor screening for Lynch syndrome: Assessment of the perspectives of patients with colorectal cancer regarding benefits and barriers

    PubMed Central

    Zepp, Jamilyn M.; Gilmore, Mari J.; Davis, James V.; Esterberg, Elizabeth J.; Muessig, Kristin R.; Peterson, Susan K.; Syngal, Sapna; Acheson, Louise S.; Wiesner, Georgia L.; Reiss, Jacob A.; Goddard, Katrina A.B.

    2015-01-01

    BACKGROUND Universal tumor screening for Lynch syndrome, the most common form of hereditary colorectal cancer (CRC), has been recommended among all patients newly diagnosed with CRC. However, there is limited literature regarding patient perspectives of tumor screening for Lynch syndrome among patients with CRC who are not selected for screening based on family history criteria. METHODS A total of 145 patients aged 39 to 87 years were administered surveys assessing perceived risk, patient perspectives, and potential benefits of and barriers to tumor screening for Lynch syndrome. Associations between patient‐specific and cancer‐specific factors and survey responses were analyzed. RESULTS The majority of participants perceived their risk of developing Lynch syndrome as being low, with 9 participants (6.2%) anticipating an abnormal screening result. However, most participants endorsed the potential benefits of screening for themselves and their families, with 84.8% endorsing ≥6 benefits and 50.3% endorsing all 8 benefits. Participants also endorsed few potential barriers to screening, with 89.4% endorsing ≤4 of 9 potential barriers. A common barrier was worry about the cost of additional testing and surveillance, which was endorsed by 54.5% of participants. The level of distress associated with tumor screening for Lynch syndrome, which was very low, was not associated with age or CRC stage. CONCLUSIONS The results of the current study indicate that patients with CRC overall have a positive attitude toward tumor screening for Lynch syndrome, endorse the benefits of screening, and experience low levels of distress. These findings provide insight into patient attitudes toward tumor screening for Lynch syndrome among unselected patients with CRC to inform educational approaches that assist in patient decision‐making and guide the successful implementation of screening programs. Cancer 2015;121:3281–3289. © 2015 American Cancer Society. PMID:26036338

  1. MR assessment of radiation-induced blood-brain barrier permeability changes in a rat glioma model

    SciTech Connect

    Krueck, W.G. Univ. of Washington School of Medicine, Seattle, WA ); Schmiedl, U.P.; Maravilla, K.R.; Starr, F.L.; Kenney, J. )

    1994-04-01

    To assess the potential of a T1-weighted, gadolinium-enhanced MR technique for quantifying radiation-induced changes of blood-brain barrier permeability in a model of stereotactically implanted intracerebral gliomas in rats. We calculated the gadolinium blood-to-tissue transport coefficient for gadopentetate dimeglumine from signal intensities in sequential MR images in nine control animals that were not irradiated and in five and three animals that had received 2500 cGy and 1500 cGy whole-brain irradiation, respectively, at 2 days before imaging. The average blood-to-tissue transport coefficient values were 9.76 mL[center dot]kg[sup [minus]1][center dot]min[sup [minus]1] in the control group, 23.41 mL[center dot]kg[sup [minus]1][center dot]min[sup [minus]1] in the 2500-cGy group, and 25.63 mL[center dot]kg[sup [minus]1][center dot]min[sup [minus]1] in the 1500-cGy group. Blood-to-tissue transport coefficients were significantly higher after irradiation, indicating increased radiation-induced blood-brain barrier permeability. Similar increased blood-brain barrier leakiness in brain tumors after high-dose irradiation has been shown by previous nuclear medicine studies using quantitative autoradiography. Contrast-enhanced dynamic MR of brain gliomas is a sensitive method to document radiation-induced blood-brain barrier breakdown. Quantitative gadolinium-enhanced MR may become a useful tool for the management of patients with brain tumors undergoing radiation therapy. 28 refs., 4 figs., 1 tab.

  2. Prevention of secondary conditions in fetal alcohol spectrum disorders: identification of systems-level barriers.

    PubMed

    Petrenko, Christie L M; Tahir, Naira; Mahoney, Erin C; Chin, Nancy P

    2014-08-01

    Fetal alcohol spectrum disorders (FASD) impact 2-5% of the US population and are associated with life-long cognitive and behavioral impairments. Individuals with FASD have high rates of secondary conditions, including mental health problems, school disruptions, and trouble with the law. This study focuses on systems-level barriers that contribute to secondary conditions and interfere with prevention and treatment. Using a phenomenological methodology, semi-structured interviews and focus groups were conducted with parents of children with FASD and service providers. Data were analyzed using a framework approach. Participants emphasized the pervasive lack of knowledge of FASD throughout multiple systems. This lack of knowledge contributes to multi-system barriers including delayed diagnosis, unavailability of services, and difficulty qualifying for, implementing, and maintaining services. FASD is a major public health problem. Broad system changes using a public health approach are needed to increase awareness and understanding of FASD, improve access to diagnostic and therapeutic services, and create responsive institutional policies to prevent secondary conditions. These changes are essential to improve outcomes for individuals with FASD and their families and facilitate dissemination of empirically supported interventions.

  3. Evolution of fusion hindrance for asymmetric systems at deep sub-barrier energies

    NASA Astrophysics Data System (ADS)

    Shrivastava, A.; Mahata, K.; Pandit, S. K.; Nanal, V.; Ichikawa, T.; Hagino, K.; Navin, A.; Palshetkar, C. S.; Parkar, V. V.; Ramachandran, K.; Rout, P. C.; Kumar, Abhinav; Chatterjee, A.; Kailas, S.

    2016-04-01

    Measurements of fusion cross-sections of 7Li and 12C with 198Pt at deep sub-barrier energies are reported to unravel the role of the entrance channel in the occurrence of fusion hindrance. The onset of fusion hindrance has been clearly observed in 12C +198Pt system but not in 7Li +198Pt system, within the measured energy range. Emergence of the hindrance, moving from lighter (6,7Li) to heavier (12C, 16O) projectiles is explained employing a model that considers a gradual transition from a sudden to adiabatic regime at low energies. The model calculation reveals a weak effect of the damping of coupling to collective motion for the present systems as compared to that obtained for systems with heavier projectiles.

  4. A new technique for making bright proton bunches using barrier RF systems

    SciTech Connect

    Bhat, C.M.; /Fermilab

    2005-05-01

    I describe here a very promising scheme for producing bright proton bunches for proton-antiproton and proton-proton colliders. The method is based on the use of wide-band barrier rf systems. First, I explain the principle of the method. The beam dynamics simulations applied to the Fermilab Main Injector (MI) suggest that the scheme allows a wide range of bunch intensities and emittances for ppbar collider. This method has the potential to increase the instantaneous luminosity by {ge}30% at the Tevatron.

  5. Role of histaminergic system in blood-brain barrier dysfunction associated with neurological disorders.

    PubMed

    Bañuelos-Cabrera, Ivette; Valle-Dorado, María Guadalupe; Aldana, Blanca Irene; Orozco-Suárez, Sandra Adela; Rocha, Luisa

    2014-11-01

    Blood-brain barrier (BBB) disruption has been associated with several acute and chronic brain disorders such as Alzheimer's disease, Parkinson's disease and epilepsy. This represents a critical situation because damaged integrity of the BBB is related to the influx of immune mediators, plasma proteins and other outside elements from blood to the central nervous system (CNS) that may trigger a cascade of events that leads to neuroinflammation. In this review, evidence that mast cells and the release of factors such as histamine play an important role in the neuroinflammatory process associated with brain disorders such as Alzheimer's disease, Parkinson's disease and epilepsy is presented.

  6. Burden of Circulatory System Diseases and Ignored Barriers of Knowledge Translation

    PubMed Central

    Ghafouri, Hamed-Basir; Saravani, Shahzad; Shokraneh, Farhad

    2012-01-01

    Circulatory system disease raise third highest disability-adjusted life years among Iranians and ischemic cardiac diseases are main causes for such burden. Despite available evidences on risk factors of the disease, no effective intervention was implemented to control and prevent the disease. This paper non-systematically reviews available literature on the problem, solutions, and barriers of implementation of knowledge translation in Iran. It seems that there are ignored factors such as cultural and motivational issues in knowledge translation interventions but there are hopes for implementation of started projects and preparation of students as next generation of knowledge transferors. PMID:24250994

  7. Interactions between surface discharges induced by volume discharges in a dielectric barrier discharge system

    SciTech Connect

    Gao, Yenan; Dong, Lifang Zhao, Longhu; Wang, Yongjie; Pan, Yuyang; Li, Ben

    2014-10-15

    The interaction between micro-discharges involved in surface discharges (SDs) is studied in dielectric barrier discharge system. Instantaneous images taken by high speed cameras show that the SDs are induced by volume discharges (VDs). They cannot cross the midperpendicular of two neighbouring volume charges at low voltage while they stretch along it at high voltage, indicating that there is interaction between SDs. The differences of plasma parameters between SD and VD are studied by optical emission spectroscopy. The simulation of the electric fields of the wall charges accumulated by VD further confirms the existence of the interaction.

  8. OVERCOMING THE METER BARRIER AND THE FORMATION OF SYSTEMS WITH TIGHTLY PACKED INNER PLANETS (STIPs)

    SciTech Connect

    Boley, A. C.; Morris, M. A.; Ford, E. B.

    2014-09-10

    We present a solution to the long outstanding meter barrier problem in planet formation theory. As solids spiral inward due to aerodynamic drag, they will enter disk regions that are characterized by high temperatures, densities, and pressures. High partial pressures of rock vapor can suppress solid evaporation, and promote collisions between partially molten solids, allowing rapid growth. This process should be ubiquitous in planet-forming disks, which may be evidenced by the abundant class of Systems with Tightly packed Inner Planets discovered by the NASA Kepler Mission.

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  10. Assessment in Higher Education: Drivers, Barriers and Directions for Change in the UK

    ERIC Educational Resources Information Center

    Medland, Emma

    2016-01-01

    Assessment is fundamental to student learning and achievement. However, whilst research consistently emphasises the role of assessment in supporting the development of the learner, the reality of assessment processes and practices in higher education is frequently indicated to fall someway short. This article aims to contribute to a shared…

  11. Interim Results of a National Test of the Rapid Assessment of Hospital Procurement Barriers in Donation (RAPiD)

    PubMed Central

    Traino, H. M.; Alolod, G. P.; Shafer, T.; Siminoff, L. A.

    2012-01-01

    Organ donation remains a major public health challenge with over 114 000 people on the waitlist in the United States. Among other factors, extant research highlights the need to improve the identification and timely referral of potential donors by hospital health-care providers (HCPs) to organ procurement organizations (OPOs). We implemented a national test of the Rapid Assessment of hospital Procurement barriers in Donation (RAPiD) to identify assets and barriers to the organ donation and patient referral processes; assess hospital–OPO relationships and offer tailored recommendations for improving these processes. Having partnered with seven OPOs, data were collected at 70 hospitals with high donor potential in the form of direct observations and interviews with 2358 HCPs. We found that donation attitudes and knowledge among HCPs were high, but use of standard referral criteria was lacking. Significant differences were found in the donation-related attitudes, knowledge and behaviors of physicians and emergency department staff as compared to other staff in intensive care units with high organ donor potential. Also, while OPO staff were generally viewed positively, they were often perceived as outsiders rather than members of healthcare teams. Recommendations for improving the referral and donation processes are discussed. PMID:22900761

  12. Numerical evaluation of cement/bentonite interactions in engineered barrier systems

    NASA Astrophysics Data System (ADS)

    Nakarai, K.; Ishida, T.

    2009-04-01

    We investigate the use of concrete in combination with bentonite in engineered barrier systems of radioactive waste deposits. Such barriers must remain stable for several tens of thousands of years, which is far longer than the lifetime of conventional infrastructure. In this study a multi-phase physicochemical method for the prediction of the long-term degradation of concrete by calcium leaching is presented. We developed a unified approach that can be used for both, concrete and bentonite as well as their interaction in the engineered barrier system. To predict the degradation of cement by calcium leaching, solid-solution equilibrium of calcium ions and their transport are formulated on the basis of thermodynamic laws and calibrated to experimental data. In the bentonite domain, the proposed equilibrium formulation considers ions bound by ion exchange, as well as ion absorption on its microstructure. The parameters of the model are based on experiments with block samples of highly compacted bentonite. Transport of calcium ions is modeled by considering diffusion and advection in the pore structure. We verified the model by comparing it to calcium leaching experiments of concrete in contact with bentonite. The analysis of the experiments revealed that the rate of deterioration is massively increased when the concrete was in contact with bentonite. This is caused by a high calcium concentration gradient between the concrete and the surrounding bentonite. In the bentonite a low concentration of free calcium ions in the pore water is maintained due to ion exchange and adsorption of calcium onto the clay. We conclude that it is important to account for the effect of bentonite on the degradation process of concrete.

  13. Sub-barrier fusion of {sup 36}S + {sup 64}Ni and other medium-light systems

    SciTech Connect

    Montagnoli, G.; Scarlassara, F.; Stefanini, A. M.; Corradi, L.; Fioretto, E.; Silvestri, R.; Courtin, S.; Haas, F.; Lebhertz, D.; Szilner, S.

    2010-12-15

    Sub-barrier fusion cross sections of {sup 36}S + {sup 64}Ni have been measured down to {approx_equal}3 {mu}b. The logarithmic slope of the fusion excitation function has a steep rise in the barrier region with decreasing energy and saturates at lower energies. The data can be reproduced within the coupled-channels model using a Woods-Saxon potential with a large diffuseness. The slope saturation is analogous to what has been observed for {sup 36}S, {sup 48}Ca + {sup 48}Ca, while for heavier systems the slope increases steadily below the barrier.

  14. Optimization of the Ni-Cr-Al-Y/ZrO2-Y2O3 thermal barrier system

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1986-01-01

    The effects of bond and thermal barrier coating compositions, thicknesses, and densities on air plasma spray deposited Ni-Cr-Al-Y/ZrO2-Y2O3 life were evaluated in cyclic furnace oxidation tests at temperatures from 1110 to 1220 C. An empirical relation was developed to give life as a function of the above parameters. The thermal barrier system tested which had the longest life consisted of Ni-35.0 wt pct Cr-5.9 wt pct Al-0.95 wt pct Y bond coating and ZrO2-6.1 wt pct Y2O3 thermal barrier coating.

  15. Optimization of the NiCrAl-Y/ZrO-Y2O3 thermal barrier system

    NASA Technical Reports Server (NTRS)

    Stecura, S.

    1985-01-01

    The effects of bond and thermal barrier coating compositions, thicknesses, and densities on air plasma spray deposited Ni-Cr-Al-Y/ZrO2-Y2O3 life were evaluated in cyclic furnace oxidation tests at temperatures from 1110 to 1220 C. An empirical relation was developed to give life as a function of the above parameters. The thermal barrier system tested which had the longest life consisted of Ni-35.0 wt% Cr-5.9 wt% Al-0.95 wt% Y bond coating and ZrO2-6.1 wt% Y2O3 thermal barrier coating.

  16. Assessment of barriers to bone marrow donation by unrelated African-American potential donors.

    PubMed

    Laver, J H; Hulsey, T C; Jones, J P; Gautreaux, M; Barredo, J C; Abboud, M R

    2001-01-01

    African Americans have a lower registration rate for becoming potential bone marrow and stem cell donors. The same attitudes and behaviors are exhibited in regard to solid organ and blood donations, causing a serious under-representation of the African-American population in the donor pool. In our efforts to increase donor availability for African Americans through a project funded by the Medical University of South Carolina, we used a survey to determine the reasons African Americans do not participate as donors for bone marrow. We surveyed 589 African Americans, a great majority of whom were women. Our survey identified major barriers to donation to be the lack of awareness that transplantation can save lives, the cost of donation, and the lack of opportunities to donate. The most effective interventions in increasing donation have been to provide both educational programs preceding marrow drives and the opportunity to donate. Through these efforts, the number of potential African-American donors has increased from 768 (accrued over a period of 12 years) to 1977 in less than 2 years. We conclude that a minority recruitment program targeting African-American volunteers for the National Marrow Donor Program (NMDP) should include an education component addressing the most common barriers before drives.

  17. Efficiency assessment of vertical barriers on the basis of flow and transport numerical modeling

    NASA Astrophysics Data System (ADS)

    Koda, Eugeniusz; Kołanka, Tomasz; Osiński, Piotr

    2012-10-01

    The construction of cut-off walls is a common solution applied in such disciplines as land reclamation and landfill containment. Most commonly the construction of vertical barriers is based on cut-off wall mono or diphase technology with the use of bentonite-cement mixture as a filling material. The content of the paper is focused on groundwater flow and transport numerical modeling conducted on landfill areas where vertical bentonite barriers were constructed. The modeling process was conducted with the use of FEMWATER software which employs analysis based on finite element method. There are two examples of the software application presented in the paper which concern such case studies, i.e., reclamation of Radiowo and Łubna landfill sites. These examples are provided to prove that the appropriate investigation of ground conditions as well as definition of initial and boundary conditions and correct selection of material parameters to be fed into the software, are crucial for the overall modeling process. Moreover, the comparison of results obtained from the numerical modeling and the groundwater monitoring on site is presented for one of the case studies.

  18. Preventing childhood obesity through state policy: qualitative assessment of enablers and barriers.

    PubMed

    Dodson, Elizabeth A; Fleming, Chris; Boehmer, Tegan K; Haire-Joshu, Debra; Luke, Douglas A; Brownson, Ross C

    2009-01-01

    As the prevalence of obesity rapidly climbs among youth in the United States, public health practitioners and policymakers seek effective means of slowing and reversing these trends. Recently, many state laws and regulations addressing childhood obesity have been introduced and enacted. Understanding determinants of such legislation may inform the development and passage of future policies. For this study, key-informant interviews were conducted with 16 legislators and staffers from 11 states in 2005-2006 to examine qualitative factors that enable and impede state-level childhood obesity prevention legislation. Commonly cited factors positively influencing the passage of childhood obesity prevention legislation included national media exposure, introduction of the policy by senior legislators, and gaining the support of key players including parents, physicians, and schools. Noteworthy barriers included powerful lobbyists of companies that produce unhealthy foods and misconceptions about legislating foods at schools. Although the total number of informants was modest, their valuable insights provide policymakers and practitioners with a set of enablers and barriers to be considered when pursuing state-level policy. PMID:19190572

  19. Assessing Barriers to the Use of Fall Protection in Small Residential Construction Companies in New Jersey.

    PubMed

    Borjan, Marija; Patel, Toral; Lefkowitz, Daniel; Campbell, Carla; Lumia, Margaret

    2016-05-01

    Three focus groups were conducted with residential construction workers from local New Jersey labor organizations to characterize barriers to fall protection use among residential construction contractors who work for companies with fewer than ten employees. Thirty-six residential construction workers volunteered to participate, the average age was thirty-nine years, and twenty-four (67%) were of Hispanic origin. Twelve (33%) of the participants reported having fallen from greater than 6 ft at work and twenty (56%) of the participants had known someone who has fallen from greater than 6 ft. Sixteen (44%) had not been provided with fall protection equipment by their employer and eighteen (50%) reported their current employer had not provided workplace safety training. Factors that created barriers to use of fall protection equipment such as equipment availability, employee/employer relationships, cultural differences, and company size were identified. Results from this study confirm that falls remain a concern among residential construction workers in small companies.

  20. Assessing the potential underestimation of sediment and nutrient loads to the Great Barrier Reef lagoon during floods.

    PubMed

    Wallace, Jim; Karim, Fazlul; Wilkinson, Scott

    2012-01-01

    Much of the sediment and nutrient load to the Great Barrier Reef (GBR) lagoon happens during over bank floods, when discharge can be significantly underestimated by standard river gauges. This paper assesses the potential need for a flood load correction for 28 coastal rivers that discharge into the GBR lagoon. For each river, daily discharge was divided into flows above and below a 'flood' threshold to calculate the mean annual percentage flow above this threshold. Most GBR rivers potentially need a flood load correction as over 15% of their mean annual flow occurs above the minor flood level; only seven rivers need little/no correction as their flood flows were less than 5% of the mean annual flow. Improved assessment of the true load of materials to the GBR lagoon would be an important contribution to the monitoring and reporting of progress towards Reef Plan and associated marine load targets.

  1. Oligoclonal banding of IgG in CSF, blood-brain barrier function, and MRI findings in patients with sarcoidosis, systemic lupus erythematosus, and Behçet's disease involving the nervous system.

    PubMed Central

    McLean, B N; Miller, D; Thompson, E J

    1995-01-01

    A retrospective study of CSF and serum analysis from a total of 43 patients with sarcoidosis, 20 with systemic lupus erythematosus, and 12 with Behçet's disease with neurological involvement found local synthesis of oligoclonal IgG using isoelectric focusing and immunoblotting in 51%, 25%, and 8% respectively at some stage in their disease. Blood-brain barrier breakdown, when assessed with an albumin ratio found 47% of patients with sarcoidosis, 30% of those with systemic lupus erythematosus, and 42% of patients with Behçet's disease exhibiting abnormal barrier function at some time. Serial CSF analysis showed that clinical relapses were associated with worsening barrier function and in some patients the development of local oligoclonal IgG synthesis; conversely steroid treatment led to a statistically significant improvement in barrier function, and in two patients a loss of oligoclonal IgG bands. A higher proportion of patients had MRI abnormalities than oligoclonal IgG or blood-brain barrier breakdown, MRI being abnormal in 16 of 19 patients with sarcoidosis, three of four patients with systemic lupus erythematosus, and seven of nine patients with Behçet's disease, although this may have been due to temporal factors. In the differential diagnosis of chronic neurological disorders, locally synthesised oligoclonal IgG cannot distinguish between diseases, but the loss of bands seen in two patients contrasts with what is seen in multiple sclerosis, and thus may be a useful diagnostic clue. PMID:7745401

  2. Systems and methods for measuring a parameter of a landfill including a barrier cap and wireless sensor systems and methods

    DOEpatents

    Kunerth, Dennis C.; Svoboda, John M.; Johnson, James T.

    2007-03-06

    A method of measuring a parameter of a landfill including a cap, without passing wires through the cap, includes burying a sensor apparatus in the landfill prior to closing the landfill with the cap; providing a reader capable of communicating with the sensor apparatus via radio frequency (RF); placing an antenna above the barrier, spaced apart from the sensor apparatus; coupling the antenna to the reader either before or after placing the antenna above the barrier; providing power to the sensor apparatus, via the antenna, by generating a field using the reader; accumulating and storing power in the sensor apparatus; sensing a parameter of the landfill using the sensor apparatus while using power; and transmitting the sensed parameter to the reader via a wireless response signal. A system for measuring a parameter of a landfill is also provided.

  3. Improving vascular access outcomes: a systems approach to eliminating structural barriers.

    PubMed

    Sands, Jeffrey J; Perry, Michael A

    2003-01-01

    Maximizing AV fistula creation, regular access monitoring, prompt outpatient interventions and minimizing catheter use are well-accepted approaches for vascular access management. Systemic barriers impede the application of these strategies. A misaligned reimbursement system coupled with educational deficits and a lack of accountability has contributed to the institutionalization of substandard vascular access care. The hallmark of performance management is to create systems in which incentives are aligned to produce desired behaviors. Realigning reimbursement through a combination of pre-ESRD funding, enhancements to the composite rate to reward outcomes and cover vascular access monitoring and updated reimbursement for outpatient vascular access procedures would improve care and decrease unnecessary hospitalizations. This should be coupled with clearly defined outcome standards and accountability incorporated into hospital accreditation and credentialing. Capitation may provide alternative solutions. A two-phased approach including reimbursement reform while exploring capitation represents a prudent course with the best likelihood of success. PMID:12596756

  4. Thermal Fatigue Behavior of Thick and Porous Thermal Barrier Coatings Systems

    NASA Astrophysics Data System (ADS)

    Scrivani, A.; Rizzi, G.; Bardi, U.; Giolli, C.; Miranda, M. Muniz; Ciattini, S.; Fossati, A.; Borgioli, F.

    2007-12-01

    High-temperature thermal fatigue causes the failure of thermal barrier coating (TBC) systems. This paper addresses the development of thick TBCs, focusing on the microstructure and the porosity of the yttria partially stabilized zirconia (YPSZ) coating, regarding its resistance to thermal fatigue. Thick TBCs, with different porosity levels, were produced by means of a CoNiCrAlY bond coat and YPSZ top coat, both had been sprayed by air plasma spray. The thermal fatigue resistance of new TBC systems and the evolution of the coatings before and after thermal cycling was then evaluated. The limit of thermal fatigue resistance increases depending on the amount of porosity in the top coat. Raman analysis shows that the compressive in-plane stress increases in the TBC systems after thermal cycling, nevertheless the increasing rate has a trend which is contrary to the porosity level of top coat.

  5. Barriers to appropriate care for mothers and infants during the perinatal period in rural Afghanistan: A qualitative assessment

    PubMed Central

    Newbrander, William; Natiq, Kayhan; Shahim, Shafiqullah; Hamid, Najibullah; Skena, Naomi Brill

    2013-01-01

    This study, conducted in five rural districts in Afghanistan, used qualitative methods to explore traditional practices of women, families and communities related to maternal and newborn care, and sociocultural and health system issues that create access barriers. The traditional practices discussed include delayed bathing of mothers and delayed breastfeeding of infants, seclusion of women after childbirth, restricted maternal diet, and use of traditional home remedies and self-medication instead of care in health facilities to treat maternal and newborn conditions. This study also looked at community support structures, transportation and care-seeking behaviour for maternal and newborn problems which create access barriers. Sociocultural barriers to better maternal-newborn health include shame about utilisation of maternal and neonatal services, women's inability to seek care without being accompanied by a male relative, and care-seeking from mullahs for serious health concerns. This study also found a high level of post-partum depression. Targeted and more effective behaviour-change communication programmes are needed. This study presents a set of behaviour-change messages to reduce maternal and newborn mortality associated with births occurring at home in rural communities. This study recommends using religious leaders, trained health workers, family health action groups and radio to disseminate these messages. PMID:24003851

  6. Understanding the system in risk assessment

    SciTech Connect

    Craft, R.; Vandewart, R.; Wyss, G.; Funkhouser, D.

    1998-02-01

    In the assessment of a system, understanding the system is central. Even so, most of the current literature takes a narrow view of understanding, making only the catalog of system ``assets`` explicit, while maintaining the balance of the analyst`s understanding inside the analyst`s head. This can lead to problems with non-repeatability and incompleteness of assessment results. This paper introduces the notion of using explicit system models to document the analyst`s understanding of the system and shows that, from these models, standard assessment products, such as fault trees and event trees, can be automatically derived. This paper also presents five ``views`` of a system that can be used to document the analyst`s understanding of the system. These views go well beyond the standard instruction to identify the system`s assets to show that a much richer understanding of the system can be required for effective assessment.

  7. Advanced vehicle systems assessment. Volume 2: Subsystems assessment

    NASA Technical Reports Server (NTRS)

    Hardy, K.

    1985-01-01

    Volume 2 (Subsystems Assessment) is part of a five-volume report entitled Advanced Vehicle Systems Assessment. Volume 2 presents the projected performance capabilities and cost characteristics of applicable subsystems, considering an additional decade of development. Subsystems of interest include energy storage and conversion devices as well as the necessary powertrain components and vehicle subsystems. Volume 2 also includes updated battery information based on the assessment of an independent battery review board (with the aid of subcontractor reports on advanced battery characteristics).

  8. Graphene as a diffusion barrier for isomorphous systems: Cu-Ni system

    NASA Astrophysics Data System (ADS)

    Roy, Apurba; Punith Kumar, M. K.; Srivastava, Chandan

    2016-02-01

    Electrochemical exfoliation technique using the pyrophosphate anion derived from tetra sodium pyrophosphate was employed to produce graphene. As-synthesized graphene was then drop dried over a cold rolled Cu sheet. Ni coating was then electrodeposited over bare Cu and graphene-Cu substrates. Both substrates were then isothermally annealed at 800 °C for 3 h. WDS analysis showed substantial atomic diffusion in annealed Ni-Cu sample. Cu-graphene-Ni sample, on the other hand, showed negligible diffusion illustrating the diffusion barrier property of the graphene coating.

  9. An assessment of an environmental gradient using coral geochemical records, Whitsunday Islands, Great Barrier Reef, Australia.

    PubMed

    Lewis, S E; Brodie, J E; McCulloch, M T; Mallela, J; Jupiter, S D; Williams, H Stuart; Lough, J M; Matson, E G

    2012-01-01

    Coral cores were collected along an environmental and water quality gradient through the Whitsunday Island group, Great Barrier Reef (Australia), for trace element and stable isotope analysis. The primary aim of the study was to examine if this gradient could be detected in coral records and, if so, whether the gradient has changed over time with changing land use in the adjacent river catchments. Y/Ca was the trace element ratio which varied spatially across the gradient, with concentrations progressively decreasing away from the river mouths. The Ba/Ca and Y/Ca ratios were the only indicators of change in the gradient through time, increasing shortly after European settlement. The Mn/Ca ratio responded to local disturbance related to the construction of tourism infrastructure. Nitrogen isotope ratios showed no apparent trend over time. This study highlights the importance of site selection when using coral records to record regional environmental signals. PMID:22030106

  10. An assessment of an environmental gradient using coral geochemical records, Whitsunday Islands, Great Barrier Reef, Australia.

    PubMed

    Lewis, S E; Brodie, J E; McCulloch, M T; Mallela, J; Jupiter, S D; Williams, H Stuart; Lough, J M; Matson, E G

    2012-01-01

    Coral cores were collected along an environmental and water quality gradient through the Whitsunday Island group, Great Barrier Reef (Australia), for trace element and stable isotope analysis. The primary aim of the study was to examine if this gradient could be detected in coral records and, if so, whether the gradient has changed over time with changing land use in the adjacent river catchments. Y/Ca was the trace element ratio which varied spatially across the gradient, with concentrations progressively decreasing away from the river mouths. The Ba/Ca and Y/Ca ratios were the only indicators of change in the gradient through time, increasing shortly after European settlement. The Mn/Ca ratio responded to local disturbance related to the construction of tourism infrastructure. Nitrogen isotope ratios showed no apparent trend over time. This study highlights the importance of site selection when using coral records to record regional environmental signals.

  11. Regulation of Copper Transport Crossing Brain Barrier Systems by Cu-ATPases: Effect of Manganese Exposure

    PubMed Central

    Fu, Xue; Zhang, Yanshu; Jiang, Wendy; Monnot, Andrew Donald; Bates, Christopher Alexander; Zheng, Wei

    2014-01-01

    Regulation of cellular copper (Cu) homeostasis involves Cu-transporting ATPases (Cu-ATPases), i.e., ATP7A and ATP7B. The question as to how these Cu-ATPases in brain barrier systems transport Cu, i.e., toward brain parenchyma, cerebrospinal fluid (CSF), or blood, remained unanswered. This study was designed to characterize roles of Cu-ATPases in regulating Cu transport at the blood-brain barrier (BBB) and blood-CSF barrier (BCB) and to investigate how exposure to toxic manganese (Mn) altered the function of Cu-ATPases, thereby contributing to the etiology of Mn-induced parkinsonian disorder. Studies by quantitative real-time RT-PCR (qPCR), Western blot, and immunocytochemistry revealed that both Cu-ATPases expressed abundantly in BBB and BCB. Transport kinetic studies by in situ brain infusion and ventriculo-cisternal (VC) perfusion in Sprague Dawley rat suggested that the BBB was a major site for Cu entry into brain, whereas the BCB was a predominant route for Cu efflux from the CSF to blood. Confocal evidence showed that the presence of excess Cu or Mn in the choroid plexus cells led to ATP7A relocating toward the apical microvilli facing the CSF, but ATP7B toward the basolateral membrane facing blood. Mn exposure inhibited the production of both Cu-ATPases. Collectively, these data suggest that Cu is transported by the BBB from the blood to brain, which is mediated by ATP7A in brain capillary. By diffusion, Cu ions move from the interstitial fluid into the CSF, where they are taken up by the BCB. Within the choroidal epithelial cells, Cu ions are transported by ATP7B back to the blood. Mn exposure alters these processes, leading to Cu dyshomeostasis-associated neuronal injury. PMID:24614235

  12. Corneal penetration behavior of beta-blocking agents II: Assessment of barrier contributions.

    PubMed

    Huang, H S; Schoenwald, R D; Lach, J L

    1983-11-01

    Rabbit corneas were excised and mounted in a chamber to determine the permeability characteristics of a group of beta-blocking agents. By measuring the permeability rate of each drug across intact cornea, stroma alone, epithelium-stroma, and stroma-endothelium, it was possible to determine the resistance to penetration for each corneal layer. The reciprocal of the sum of resistances for the epithelium, stroma, and endothelium equaled the experimentally determined permeability coefficient for the intact cornea (104 +/- 6.0%). Thus, the penetration of beta-blocking agents through the excised rabbit cornea could be treated as three barriers in series. For hydrophilic compounds, the epithelium was the rate-determining barrier. The endothelium offered less resistance, whereas the stroma offered only very minimal resistance. The lipophilic compounds penetrated the excised cornea more rapidly. However, the stroma became rate-determining for the most lipophilic compounds (penbutolol, bufuralol, bevantolol, and propranolol). Although the octanol-buffer (pH 7.65) distribution coefficient of these compounds varied over a fourfold logarithmic range, the permeability coefficient was considered nearly constant [3.4 X 10(-5) (+/- 0.34) cm/sec] for stroma. Also, the ratios of tortuosity to porosity for the stromal layer were 1.58 +/- 0.15. These results suggest that drug diffuses through an aqueous media of gel-like mucopolysaccharide interspersed by a matrix of collagen fibrils. From further analyses intra- and intercellular pathways for epithelium and endothelium were added to the model resulting in a sigmoidal representation of permeability coefficient versus distribution coefficient. However, the intercellular (pore) pathway could not be adequately quantified because of the variation in the data for very hydrophilic compounds.

  13. Perceived interprofessional barriers between community pharmacists and general practitioners: a qualitative assessment.

    PubMed Central

    Hughes, Carmel M; McCann, Siobhan

    2003-01-01

    BACKGROUND: There have been calls for greater collaboration between general practitioners (GPs) and community pharmacists in primary care. AIM: To explore barriers between the two professions in relation to closer interprofessional working and the extension of prescribing rights to pharmacists. DESIGN OF STUDY: Qualitative study. SETTING: Three locality areas of a health and social services board in Northern Ireland. METHOD: GPs and community pharmacists participated in uniprofessional focus groups; data were analysed using interpretative phenomenology. RESULTS: Twenty-two GPs (distributed over five focus groups) and 31 pharmacists (distributed over six focus groups) participated in the study. The 'shopkeeper' image of community pharmacy emerged as the superordinate theme, with subthemes of access, hierarchy and awareness. The shopkeeper image and conflict between business and health care permeated the GPs' discussions and accounted for their concerns regarding the extension of prescribing rights to community pharmacists and involvement inextended services. Community pharmacists felt such views influenced their position in the hierarchy of healthcare professionals. Although GPs had little problem in accessing pharmacists, they considered that patients experienced difficulties owing to the limited opening hours of pharmacies. Conversely, pharmacists reported great difficulty in accessing GPs, largely owing to the gatekeeper role of receptionists. GPs reported being unaware of the training and activities of community pharmacists and participating pharmacists also felt that GPs had no appreciation of their role in health care. CONCLUSION: A number of important barriers between GPs and community pharmacists have been identified, which must be overcome if interprofessional liaison between the two professions is to be fully realised. PMID:14601335

  14. Geotechnical Issues in Total System Performance Assessments of Yucca Mountain

    SciTech Connect

    HO,CLIFFORD K.; HOUSEWORTH,JIM; WILSON,MICHAEL L.

    1999-12-21

    A Total System Performance Assessment (TSPA) of Yucca Mountain consists of integrated sub-models and analyses of natural and engineered systems. Examples of subsystem models include unsaturated-zone flow and transport, seepage into drifts, coupled thermal hydrologic processes, transport through the engineered barrier system, and saturated-zone flow and transport. The TSPA evaluates the interaction of important processes among these subsystems, and it determines the impact of these processes on the overall performance measures (e.g., dose rate to humans). This paper summarizes the evaluation, abstraction, and combination of these subsystem models in a TSPA calculation, and it provides background on the individual TSPA subsystem components that are most directly impacted by geotechnical issues. The potential impact that geologic features, events, and processes have on the overall performance is presented, and an evaluation of the sensitivity of TSPA calculations to these issues is also provided.

  15. Barriers to the Uptake and Use of Feedback in the Context of Summative Assessment

    ERIC Educational Resources Information Center

    Harrison, Christopher J.; Könings, Karen D.; Schuwirth, Lambert; Wass, Valerie; van der Vleuten, Cees

    2015-01-01

    Despite calls for feedback to be incorporated in all assessments, a dichotomy exists between formative and summative assessments. When feedback is provided in a summative context, it is not always used effectively by learners. In this study we explored the reasons for this. We conducted individual interviews with 17 students who had recently…

  16. Program Assessments: Identifying the Enabling Factors and Barriers That Affect Community College Administrators

    ERIC Educational Resources Information Center

    Corll, Thomas E.

    2011-01-01

    Discussions concerning the issue of program assessments have been ongoing for three decades. Current studies focused on the administrator's responsibilities within the post-secondary educational fields continue to overlook program assessments as a role that must be fulfilled. The deans and program directors at ABC College are expected to perform a…

  17. A gut-vascular barrier controls the systemic dissemination of bacteria.

    PubMed

    Spadoni, Ilaria; Zagato, Elena; Bertocchi, Alice; Paolinelli, Roberta; Hot, Edina; Di Sabatino, Antonio; Caprioli, Flavio; Bottiglieri, Luca; Oldani, Amanda; Viale, Giuseppe; Penna, Giuseppe; Dejana, Elisabetta; Rescigno, Maria

    2015-11-13

    In healthy individuals, the intestinal microbiota cannot access the liver, spleen, or other peripheral tissues. Some pathogenic bacteria can reach these sites, however, and can induce a systemic immune response. How such compartmentalization is achieved is unknown. We identify a gut-vascular barrier (GVB) in mice and humans that controls the translocation of antigens into the blood stream and prohibits entry of the microbiota. Salmonella typhimurium can penetrate the GVB in a manner dependent on its pathogenicity island (Spi) 2-encoded type III secretion system and on decreased β-catenin-dependent signaling in gut endothelial cells. The GVB is modified in celiac disease patients with elevated serum transaminases, which indicates that GVB dismantling may be responsible for liver damage in these patients. Understanding the GVB may provide new insights into the regulation of the gut-liver axis. PMID:26564856

  18. A gut-vascular barrier controls the systemic dissemination of bacteria.

    PubMed

    Spadoni, Ilaria; Zagato, Elena; Bertocchi, Alice; Paolinelli, Roberta; Hot, Edina; Di Sabatino, Antonio; Caprioli, Flavio; Bottiglieri, Luca; Oldani, Amanda; Viale, Giuseppe; Penna, Giuseppe; Dejana, Elisabetta; Rescigno, Maria

    2015-11-13

    In healthy individuals, the intestinal microbiota cannot access the liver, spleen, or other peripheral tissues. Some pathogenic bacteria can reach these sites, however, and can induce a systemic immune response. How such compartmentalization is achieved is unknown. We identify a gut-vascular barrier (GVB) in mice and humans that controls the translocation of antigens into the blood stream and prohibits entry of the microbiota. Salmonella typhimurium can penetrate the GVB in a manner dependent on its pathogenicity island (Spi) 2-encoded type III secretion system and on decreased β-catenin-dependent signaling in gut endothelial cells. The GVB is modified in celiac disease patients with elevated serum transaminases, which indicates that GVB dismantling may be responsible for liver damage in these patients. Understanding the GVB may provide new insights into the regulation of the gut-liver axis.

  19. Advanced Oxide Material Systems for 1650 C Thermal/Environmental Barrier Coating Applications

    NASA Technical Reports Server (NTRS)

    Zhu, Dong-Ming; Fox, Dennis S.; Bansal, Narottam P.; Miller, Robert A.

    2004-01-01

    Advanced thermal and environmental barrier coatings (TEBCs) are being developed for low-emission SiC/SiC ceramic matrix composite (CMC) combustor and vane applications to extend the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water-vapor-containing combustion environments. The advanced 1650 C TEBC system is required to have a better high-temperature stability, lower thermal conductivity, and more resistance to sintering and thermal stress than current coating systems under engine high-heat-flux and severe thermal cycling conditions. In this report, the thermal conductivity and water vapor stability of selected candidate hafnia-, pyrochlore- and magnetoplumbite-based TEBC materials are evaluated. The effects of dopants on the materials properties are also discussed. The test results have been used to downselect the TEBC materials and help demonstrate the feasibility of advanced 1650 C coatings with long-term thermal cycling durability.

  20. Advanced Oxide Material Systems For 1650 C Thermal/Environmental Barrier Coating Applications

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Fox, Dennis S.; Bansal, Narottam P.; Miller, Robert A.

    2004-01-01

    Advanced thermal/environmental barrier coatings (T/EBCs) are being developed for low emission SiC/SiC ceramic matrix composite (CMC) combustor and vane applications to extend the CMC liner and vane temperature capability to 1650 C (3000 F) in oxidizing and water-vapor containing combustion environments. The 1650 C T/EBC system is required to have better thermal stability, lower thermal conductivity, and improved sintering and thermal stress resistance than current coating systems. In this paper, the thermal conductivity, water vapor stability and cyclic durability of selected candidate zirconia-/hafnia-, pyrochlore- and magnetoplumbite-based T/EBC materials are evaluated. The test results have been used to downselect the T/EBC coating materials, and help demonstrate advanced 1650OC coatings feasibility with long-term cyclic durability.

  1. Detection of hydroxyl radicals during regeneration of granular activated carbon in dielectric barrier discharge plasma system

    NASA Astrophysics Data System (ADS)

    Tang, Shoufeng; Lu, Na; Shang, Kefeng; Li, Jie; Wu, Yan

    2013-03-01

    To understand the reactions taking place in the dielectric barrier discharge (DBD) plasma system of activated carbon regeneration, the determination of active species is necessary. A method based on High Performance Liquid Chromatography with radical trapping by salicylic acid, has been developed to measure hydroxyl radical (•OH) in the DBD plasma reactor. The effects of applied voltage, treatment time, and gas flow rate and atmosphere were investigated. Experimental results indicated that increasing voltage, treatment time and air flow rate could enhance the formation of •OH. Oxygen atmosphere and a suitable GAC water content were contributed to •OH generation. The results give an insight into plasma chemical processes, and can be helpful to optimize the design and application for the plasma system.

  2. Comparing the Dimensions of Modern and Ancient Barrier Island Systems to Understand Controls on Preservation

    NASA Astrophysics Data System (ADS)

    Mulhern, J.; Johnson, C. L.; Stright, L.

    2015-12-01

    Commonly assumed to have low preservation potential, barrier islands are rarely interpreted in the rock record, and there is little consensus on the terminology and depositional models related to their interpretation. Prevalent on transgressive coastlines, the dimensions of modern barriers are used as analogs for the ancient; however, ancient examples are complicated by post-depositional processes, including thickening through amalgamation and removal by ravinement. Contrasting the dimensions of modern and ancient examples lends insight into the development and preservation of transgressive deposits, improving the ability to predict the size and distribution of barrier island sand bodies in the rock record as well as understanding the variables that control their architecture. Interpretation of barrier island deposits from the John Henry Member (Cretaceous Straight Cliffs Fm., Kaiparowits Plateau, southern Utah) motivated an investigation into both ancient and modern barrier islands. Traditional sequence stratigraphic models predict thin condensed deposition during transgression, not accounting for possible thick and laterally extensive accumulations of barrier island deposits. More recent models recognize the possible complexity and heterogeneity of transgressive deposits and the potential for barrier island accumulation. To better understand the relationship between modern and ancient barrier islands, the length (along strike), width (dip direction) and thickness (vertical) of >20 modern and >30 ancient barrier islands were compared. Ancient dimensions were gathered from the literature, while modern dimensions were aggregated from literature and a database of modern barrier islands currently being developed. Initial results suggest that ancient barrier island deposits record the motion of the shoreline during transgression. Ancient barriers are ~2-8 times wider and ~2-3 times thicker than modern islands. The dynamics of barrier island migration and sediment

  3. River Protection Project information systems assessment

    SciTech Connect

    JOHNSON, A.L.

    1999-07-28

    The Information Systems Assessment Report documents the results from assessing the Project Hanford Management Contract (PHMC) Hanford Data Integrator 2000 (HANDI 2000) system, Business Management System (BMS) and Work Management System phases (WMS), with respect to the System Engineering Capability Assessment Model (CAM). The assessment was performed in accordance with the expectations stated in the fiscal year (FY) 1999 Performance Agreement 7.1.1, item (2) which reads, ''Provide an assessment report on the selected Integrated Information System by July 31, 1999.'' This report assesses the BMS and WMS as implemented and planned for the River Protection Project (RPP). The systems implementation is being performed under the PHMC HANDI 2000 information system project. The project began in FY 1998 with the BMS, proceeded in FY 1999 with the Master Equipment List portion of the WMS, and will continue the WMS implementation as funding provides. This report constitutes an interim quality assessment providing information necessary for planning RPP's information systems activities. To avoid confusion, HANDI 2000 will be used when referring to the entire system, encompassing both the BMS and WMS. A graphical depiction of the system is shown in Figure 2-1 of this report.

  4. Protection against malevolent use of vehicles at Nuclear Power Plants. Vehicle barrier system selection guidance

    SciTech Connect

    Nebuda, D.T.

    1994-08-01

    This manual provides a simplified procedure for selecting land vehicle barriers that will stop the design basis vehicle threat adopted by the U.S. Nuclear Regulatory Commission. Proper selection and construction of vehicle barriers should prevent intrusion of the design basis vehicle. In addition, vital safety related equipment should survive a design basis vehicle bomb attack when vehicle barriers are properly selected, sited, and constructed. This manual addresses passive vehicle barriers, active vehicle barriers, and site design features that can be used to reduce vehicle impact velocity.

  5. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system.

    PubMed

    Moon, Seheum; Nam, Kyoungphile; Kim, Jae Young; Hwan, Shim Kyu; Chung, Moonkyung

    2008-01-01

    A compacted soil liner (CSL) has been widely used as a single barrier layer or a part of composite barrier layer in the landfill final cover system to prevent water infiltration into solid wastes for its acceptable hydraulic permeability. This study was conducted to test whether the CSL was also effective in prohibiting landfill gas emissions. For this purpose, three different compaction methods (i.e., reduced, standard, and modified Proctor methods) were used to prepare the soil specimens, with nitrogen as gas, and with water and heptane as liquid permeants. Measured gas permeability ranged from 2.03 x 10(-10) to 4.96 x 10(-9) cm(2), which was a magnitude of two or three orders greater than hydraulic permeability (9.60 x 10(-13) to 1.05 x 10(-11) cm(2)). The difference between gas and hydraulic permeabilities can be explained by gas slippage, which makes gas more permeable, and by soil-water interaction, which impedes water flow and then makes water less permeable. This explanation was also supported by the result that a liquid permeability measured with heptane as a non-polar liquid was similar to the intrinsic gas permeability. The data demonstrate that hydraulic requirement for the CSL is not enough to control the gas emissions from a landfill. PMID:17964132

  6. Pathways for Small Molecule Delivery to the Central Nervous System Across the Blood-Brain Barrier

    PubMed Central

    Mikitsh, John L; Chacko, Ann-Marie

    2014-01-01

    The treatment of central nervous system (CNS) disease has long been difficult due to the ineffectiveness of drug delivery across the blood-brain barrier (BBB). This review summarizes important concepts of the BBB in normal versus pathophysiology and how this physical, enzymatic, and efflux barrier provides necessary protection to the CNS during drug delivery, and consequently treatment challenging. Small molecules account for the vast majority of available CNS drugs primarily due to their ability to penetrate the phospholipid membrane of the BBB by passive or carrier-mediated mechanisms. Physiochemical and biological factors relevant for designing small molecules with optimal capabilities for BBB permeability are discussed, as well as the most promising classes of transporters suitable for small-molecule drug delivery. Clinically translatable imaging methodologies for detecting and quantifying drug uptake and targeting in the brain are discussed as a means of further understanding and refining delivery parameters for both drugs and imaging probes in preclinical and clinical domains. This information can be used as a guide to design drugs with preserved drug action and better delivery profiles for improved treatment outcomes over existing therapeutic approaches. PMID:24963272

  7. Effectiveness of compacted soil liner as a gas barrier layer in the landfill final cover system.

    PubMed

    Moon, Seheum; Nam, Kyoungphile; Kim, Jae Young; Hwan, Shim Kyu; Chung, Moonkyung

    2008-01-01

    A compacted soil liner (CSL) has been widely used as a single barrier layer or a part of composite barrier layer in the landfill final cover system to prevent water infiltration into solid wastes for its acceptable hydraulic permeability. This study was conducted to test whether the CSL was also effective in prohibiting landfill gas emissions. For this purpose, three different compaction methods (i.e., reduced, standard, and modified Proctor methods) were used to prepare the soil specimens, with nitrogen as gas, and with water and heptane as liquid permeants. Measured gas permeability ranged from 2.03 x 10(-10) to 4.96 x 10(-9) cm(2), which was a magnitude of two or three orders greater than hydraulic permeability (9.60 x 10(-13) to 1.05 x 10(-11) cm(2)). The difference between gas and hydraulic permeabilities can be explained by gas slippage, which makes gas more permeable, and by soil-water interaction, which impedes water flow and then makes water less permeable. This explanation was also supported by the result that a liquid permeability measured with heptane as a non-polar liquid was similar to the intrinsic gas permeability. The data demonstrate that hydraulic requirement for the CSL is not enough to control the gas emissions from a landfill.

  8. Barriers to non-viral vector-mediated gene delivery in the nervous system.

    PubMed

    Pérez-Martínez, Francisco C; Guerra, Javier; Posadas, Inmaculada; Ceña, Valentín

    2011-08-01

    Efficient methods for cell line transfection are well described, but, for primary neurons, a high-yield method different from those relying on viral vectors is lacking. Viral transfection has several drawbacks, such as the complexity of vector preparation, safety concerns, and the generation of immune and inflammatory responses when used in vivo. However, one of the main problems for the use of non-viral gene vectors for neuronal transfection is their low efficiency when compared with viral vectors. Transgene expression, or siRNA delivery mediated by non-viral vectors, is the result of multiple processes related to cellular membrane crossing, intracellular traffic, and/or nuclear delivery of the genetic material cargo. This review will deal with the barriers that different nanoparticles (cationic lipids, polyethyleneimine, dendrimers and carbon nanotubes) must overcome to efficiently deliver their cargo to central nervous system cells, including internalization into the neurons, interaction with intracellular organelles such as lysosomes, and transport across the nuclear membrane of the neuron in the case of DNA transfection. Furthermore, when used in vivo, the nanoparticles should efficiently cross the blood-brain barrier to reach the target cells in the brain.

  9. Monitoring Local Strain in a Thermal Barrier Coating System Under Thermal Mechanical Gas Turbine Operating Conditions

    NASA Astrophysics Data System (ADS)

    Manero, Albert; Sofronsky, Stephen; Knipe, Kevin; Meid, Carla; Wischek, Janine; Okasinski, John; Almer, Jonathan; Karlsson, Anette M.; Raghavan, Seetha; Bartsch, Marion

    2015-07-01

    Advances in aircraft and land-based turbine engines have been increasing the extreme loading conditions on traditional engine components and have incited the need for improved performance with the use of protective coatings. These protective coatings shield the load-bearing super alloy blades from the high-temperature combustion gases by creating a thermal gradient over their thickness. This addition extends the life and performance of blades. A more complete understanding of the behavior, failure mechanics, and life expectancy for turbine blades and their coatings is needed to enhance and validate simulation models. As new thermal-barrier-coated materials and deposition methods are developed, strides to effectively test, evaluate, and prepare the technology for industry deployment are of paramount interest. Coupling the experience and expertise of researchers at the University of Central Florida, The German Aerospace Center, and Cleveland State University with the world-class synchrotron x-ray beam at the Advanced Photon Source in Argonne National Laboratory, the synergistic collaboration has yielded previously unseen measurements to look inside the coating layer system for in situ strain measurements during representative service loading. These findings quantify the in situ strain response on multilayer thermal barrier coatings and shed light on the elastic and nonelastic properties of the layers and the role of mechanical load and internal cooling variations on the response. The article discusses the experimental configuration and development of equipment to perform in situ strain measurements on multilayer thin coatings and provides an overview of the achievements thus far.

  10. Ultrathin, transferred layers of thermally grown silicon dioxide as biofluid barriers for biointegrated flexible electronic systems

    PubMed Central

    Fang, Hui; Yu, Ki Jun; Song, Enming; Farimani, Amir Barati; Chiang, Chia-Han; Jin, Xin; Xu, Dong; Du, Wenbo; Seo, Kyung Jin; Zhong, Yiding; Yang, Zijian; Won, Sang Min; Fang, Guanhua; Choi, Seo Woo; Chaudhuri, Santanu; Huang, Yonggang; Alam, Muhammad Ashraful; Viventi, Jonathan; Aluru, N. R.; Rogers, John A.

    2016-01-01

    Materials that can serve as long-lived barriers to biofluids are essential to the development of any type of chronic electronic implant. Devices such as cardiac pacemakers and cochlear implants use bulk metal or ceramic packages as hermetic enclosures for the electronics. Emerging classes of flexible, biointegrated electronic systems demand similar levels of isolation from biofluids but with thin, compliant films that can simultaneously serve as biointerfaces for sensing and/or actuation while in contact with the soft, curved, and moving surfaces of target organs. This paper introduces a solution to this materials challenge that combines (i) ultrathin, pristine layers of silicon dioxide (SiO2) thermally grown on device-grade silicon wafers, and (ii) processing schemes that allow integration of these materials onto flexible electronic platforms. Accelerated lifetime tests suggest robust barrier characteristics on timescales that approach 70 y, in layers that are sufficiently thin (less than 1 μm) to avoid significant compromises in mechanical flexibility or in electrical interface fidelity. Detailed studies of temperature- and thickness-dependent electrical and physical properties reveal the key characteristics. Molecular simulations highlight essential aspects of the chemistry that governs interactions between the SiO2 and surrounding water. Examples of use with passive and active components in high-performance flexible electronic devices suggest broad utility in advanced chronic implants. PMID:27791052

  11. Removing Barriers in the Assessment of Combat-Related Post-traumatic Stress Disorder.

    PubMed

    Yeomans, Peter D; Ross, Richard J

    2016-07-01

    While the Veterans Health Administration continues to treat Vietnam War Veterans, approximately two million service men and women have returned from Iraq and Afghanistan. However, our treatments can only be as effective as the quality of our clinical assessment. Disclosure of trauma is facilitated when the type of trauma is present in the sociocultural environment of patient and clinician. Topics that once were deemed too shameful for inquiry, specifically, childhood abuse, domestic violence, sexual abuse, and military sexual trauma are now part of a standard assessment. Similarly, the standard clinical assessment of combat Veterans should include specific queries that address the darkest underside of wartime experiences. PMID:27391614

  12. Preliminary performance assessment of the engineered barriers for a low- and intermediate-level radioactive waste repository

    SciTech Connect

    Cho, W.J.; Lee, J.O.; Hahn, P.S.; Chun, K.S.

    1996-10-01

    Radionuclide release from an engineered barrier in a low- and intermediate-level waste repository is evaluated. The results of experimental studies conducted to determine the radionuclide diffusion coefficients and the hydraulic conductivities of calcium bentonite and crushed granite mixtures are presented. The hydraulic conductivity of the mixture is relatively low even at low dry density and clay content, and the principal mechanism of radionuclide migration through the mixture is diffusion. The measured values of apparent diffusion coefficients in calcium bentonite with a dry density of 1.4 Mg/m{sup 3} are of the order of 10{sup {minus}13} to 10{sup {minus}12} m{sup 2}/s for cations and 10{sup {minus}11} m{sup 2}/s for iodine. These values are similar to those in sodium bentonite. The radionuclide release rates from the engineered barrier composed of the concrete structure and the clay-based backfill were calculated. Carbon-14 and {sup 99}Tc are the important nuclides; however, their maximum release rates are <10{sup {minus}5} GBq/yr. To quantify the effect of uncertainties of input parameters on the radionuclide release rates, Latin Hypercube sampling was used, and the ranges of release rates were estimated statistically with a confidence level of 95%. The uncertainties of the assessment results of the radionuclide release rate are larger in the case of the sorbing nuclides such as {sup 137}Cs. Finally, the sensitivity of the input parameter to release rate is also evaluated.

  13. Burning Invariant Manifold Theory and the Bipartite Digraph Representation of Generalized Dynamical System Formed by One-way Barriers

    NASA Astrophysics Data System (ADS)

    Li, John; Mahoney, John; Mitchell, Kevin; Solomon, Tom

    2013-11-01

    The recently developed Burning Invariant Manifold (BIM) theory took a dynamical system approach to understand front propagation in Advection-Reaction-Diffusion systems and successfully predicted both the short-term and asymptotic front behavior by finding the unstable BIMs which act as barriers to front propagation. Unlike separatrices in traditional dynamical system being two-way barriers, the BIMs are one-way barriers. This asymmetry gives rise to a much richer dynamical behavior than traditional dynamical systems. Through numerical simulations, we found that the stable BIMs are the basin boundaries. Based on the properties of BIM theory, we further derived a theory to investigate a dynamical system consists of one-way barriers and the cooperative behavior of these barriers. This theory reveals the global structure of both stable and unstable BIMs by first using a systematic algorithm to convert the flow to a bipartite digraph and then extracting information of the steady states of fronts and corresponding basins of attraction from the digraph. This work was supported by the US National Science Foundation under grant PHY-0748828 and NSF Fellowship DGE-0937362.

  14. 1998 FFTF annual system assessment reports

    SciTech Connect

    Guttenberg, S.

    1998-03-19

    The health of FFTF systems was assessed assuming a continued facility standby condition. The review was accomplished in accordance with the guidelines of FFTF-EI-083, Plant Evaluation Program. The attached document includes an executive summary of the significant conclusions and assessment reports for each system evaluated.

  15. Assessment of solid reactive mixtures for the development of biological permeable reactive barriers.

    PubMed

    Pagnanelli, Francesca; Viggi, Carolina Cruz; Mainelli, Sara; Toro, Luigi

    2009-10-30

    Solid reactive mixtures were tested as filling material for the development of biological permeable reactive barriers for the treatment of heavy metals contaminated waters. Mixture selection was performed by taking into account the different mechanisms operating in sulphate and cadmium removal with particular attention to bioprecipitation and sorption onto the organic matrices in the mixtures. Suspensions of eight reactive mixtures were tested for sulphate removal (initial concentration 3 g L(-1)). Each mixture was made up of four main functional components: a mix of organic sources for bacterial growth, a neutralizing agent, a porous medium and zero-valent iron. The best mixture among the tested ones (M8: 6% leaves, 9% compost, 3% zero-valent iron, 30% silica sand, 30% perlite, 22% limestone) presented optimal conditions for SRB growth (pH 7.8 +/- 0.1; E(h)= -410 +/- 5 mV) and 83% sulphate removal in 22 days (25% due to bioreduction, 32% due to sorption onto compost and 20% onto leaves). M8 mixture allowed the complete abatement of cadmium with a significant contribution of sorption over bioprecipitation (6% Cd removal due to SRB activity). Sorption properties, characterised by potentiometric titrations and related modelling, were mainly due to carboxylic sites of organic components used in reactive mixtures.

  16. Motivators and barriers to incorporating climate change-related health risks in environmental health impact assessment.

    PubMed

    Turner, Lyle R; Alderman, Katarzyna; Connell, Des; Tong, Shilu

    2013-03-22

    Climate change presents risks to health that must be addressed by both decision-makers and public health researchers. Within the application of Environmental Health Impact Assessment (EHIA), there have been few attempts to incorporate climate change-related health risks as an input to the framework. This study used a focus group design to examine the perceptions of government, industry and academic specialists about the suitability of assessing the health consequences of climate change within an EHIA framework. Practitioners expressed concern over a number of factors relating to the current EHIA methodology and the inclusion of climate change-related health risks. These concerns related to the broad scope of issues that would need to be considered, problems with identifying appropriate health indicators, the lack of relevant qualitative information that is currently incorporated in assessment and persistent issues surrounding stakeholder participation. It was suggested that improvements are needed in data collection processes, particularly in terms of adequate communication between environmental and health practitioners. Concerns were raised surrounding data privacy and usage, and how these could impact on the assessment process. These findings may provide guidance for government and industry bodies to improve the assessment of climate change-related health risks.

  17. Assessing the value of Earth Observation for managing coral reefs: an example from the Great Barrier Reef.

    PubMed

    Bouma, Jetske A; Kuik, Onno; Dekker, Arnold G

    2011-10-01

    The Integrated Global Observing Strategy (IGOS, 2003) argues that further investments in Earth Observation information are required to improve coral reef protection worldwide. The IGOS Strategy does not specify what levels of investments are needed nor does it quantify the benefits associated with better-protected reefs. Evaluating costs and benefits is important for determining optimal investment levels and for convincing policy-makers that investments are required indeed. Few studies have quantitatively assessed the economic benefits of Earth Observation information or evaluated the economic value of information for environmental management. This paper uses an expert elicitation approach based on Bayesian Decision Theory to estimate the possible contribution of global Earth Observation to the management of the Great Barrier Reef. The Great Barrier Reef including its lagoon is a World Heritage Area affected by anthropogenic changes in land-use as well as climate change resulting in increased flows of sediments, nutrients and carbon to the GBR lagoon. Since European settlement, nutrient and sediment loads having increased 5-10 times and the change in water quality is causing damages to the reef. Earth Observation information from ocean and coastal color satellite sensors can provide spatially and temporally dense information on sediment flows. We hypothesize that Earth Observation improves decision-making by enabling better-targeted run-off reduction measures and we assess the benefits (cost savings) of this improved targeting by optimizing run-off reductions under different states of the world. The analysis suggests that the benefits of Earth Observation can indeed be substantial, depending on the perceived accuracy of the information and on the prior beliefs of decision-makers. The results indicate that increasing informational accuracy is the most effective way for developers of Earth Observation information to increase the added value of Earth Observation for

  18. Assessing the value of Earth Observation for managing coral reefs: an example from the Great Barrier Reef.

    PubMed

    Bouma, Jetske A; Kuik, Onno; Dekker, Arnold G

    2011-10-01

    The Integrated Global Observing Strategy (IGOS, 2003) argues that further investments in Earth Observation information are required to improve coral reef protection worldwide. The IGOS Strategy does not specify what levels of investments are needed nor does it quantify the benefits associated with better-protected reefs. Evaluating costs and benefits is important for determining optimal investment levels and for convincing policy-makers that investments are required indeed. Few studies have quantitatively assessed the economic benefits of Earth Observation information or evaluated the economic value of information for environmental management. This paper uses an expert elicitation approach based on Bayesian Decision Theory to estimate the possible contribution of global Earth Observation to the management of the Great Barrier Reef. The Great Barrier Reef including its lagoon is a World Heritage Area affected by anthropogenic changes in land-use as well as climate change resulting in increased flows of sediments, nutrients and carbon to the GBR lagoon. Since European settlement, nutrient and sediment loads having increased 5-10 times and the change in water quality is causing damages to the reef. Earth Observation information from ocean and coastal color satellite sensors can provide spatially and temporally dense information on sediment flows. We hypothesize that Earth Observation improves decision-making by enabling better-targeted run-off reduction measures and we assess the benefits (cost savings) of this improved targeting by optimizing run-off reductions under different states of the world. The analysis suggests that the benefits of Earth Observation can indeed be substantial, depending on the perceived accuracy of the information and on the prior beliefs of decision-makers. The results indicate that increasing informational accuracy is the most effective way for developers of Earth Observation information to increase the added value of Earth Observation for

  19. A fine-scale assessment of using barriers to conserve native stream salmonids: a case study in Akokala Creek, Glacier National Park, USA

    USGS Publications Warehouse

    Muhlfeld, Clint C.; D'Angelo, Vincent S.; S. T. Kalinowski,; Landguth, Erin L.; C. C. Downs,; J. Tohtz,; Kershner, Jeffrey L.

    2012-01-01

    Biologists are often faced with the difficult decision in managing native salmonids of where and when to install barriers as a conservation action to prevent upstream invasion of nonnative fishes. However, fine-scale approaches to assess long-term persistence of populations within streams and watersheds chosen for isolation management are often lacking. We employed a spatially-explicit approach to evaluate stream habitat conditions, relative abundance, and genetic diversity of native westslope cutthroat trout (Oncorhynchus clarkii lewisi) within the Akokala Creek watershed in Glacier National Park- a population threatened by introgressive hybridization with nonnative rainbow trout (O. mykiss) from nearby sources. The systematic survey of 24 stream reaches showed broad overlap in fish population and suitable habitat characteristics among reaches and no natural barriers to fish migration were found. Analysis of population structure using 16 microsatellite loci showed modest amounts of genetic diversity among reaches, and that fish from Long Bow Creek were the only moderately distinct genetic group. We then used this information to assess the potential impacts of three barrier placement scenarios on long-term population persistence and genetic diversity. The two barrier placement scenarios in headwater areas generally failed to meet general persistence criteria for minimum population size (2,500 individuals, Ne = 500), maintenance of long-term genetic diversity (He), and no population subdivision. Conversely, placing a barrier near the stream mouth and selectively passing non-hybridized, migratory spawners entering Akokala Creek met all persistence criteria and may offer the best option to conserve native trout populations and life history diversity. Systematic, fine-scale stream habitat, fish distribution, and genetic assessments in streams chosen for barrier installation are needed in conjunction with broader scale assessments to understand the potential impacts of

  20. Advanced vehicle systems assessment. Volume 3: Systems assessment

    NASA Technical Reports Server (NTRS)

    Hardy, K.

    1985-01-01

    The systems analyses integrate the advanced component and vehicle characteristics into conceptual vehicles with identical performance (for a given application) and evaluates the vehicles in typical use patterns. Initial and life-cycle costs are estimated and compared to conventional reference vehicles with comparable technological advances, assuming the vehicles will be in competition in the early 1990s. Electric vans, commuter vehicles, and full-size vehicles, in addition to electric/heat-engine hybrid and fuel-cell powered vehicles, are addressed in terms of performance and economics. System and subsystem recommendations for vans and two-passenger commuter vehicles are based on the economic analyses in this volume.

  1. Reuse and recycling of secondary effluents in refineries employing advanced multi-barrier systems.

    PubMed

    Lahnsteiner, J; Mittal, R

    2010-01-01

    In this paper the reclamation and reuse of municipal secondary effluents, as well as the reclamation and recycling of refinery secondary effluents, are technically and economically evaluated. It is shown that both practices are feasible and sustainable, and that the reclamation costs depend largely on specific circumstances such as legal requirements, price policy, reuse application, raw water composition, etc. The reclaimed water is reused, or respectively recycled, as boiler make-up. Therefore both reclamation plants employ advanced multi-barrier systems including ultra-filtration and reverse osmosis. The employed processes have shown excellent performance with regard to the removal of critical parameters such as silica. For example, this parameter was reduced from 13 mg/l in the raw water to 7 μg/l in the boiler make-up.

  2. Reaction studies near the barrier for medium heavy systems: Ni + Sn

    SciTech Connect

    Henning, W.

    1985-01-01

    Cross sections for elastic and inelastic scattering, single- and multi-nucleon transfer, fusion followed by particle evaporation leaving an evaporation residue, and fusion followed by fission have been measured for /sup 58/ /sup 64/Ni beams incident on even Sn targets at energies from below to above the Coulomb barrier. The Ni beams were provided by the Argonne Superconducting Linac. The aim of these measurements is a comprehensive study of the reaction systematics in a medium-heavy collision system. At present, a small fraction of the data has been fully analyzed and published, a larger part is presently being compared to model calculations. Some of the data needs to be confirmed by additional measurements. This summary should be viewed as a status report and an attempt to formulate some of the open questions. 9 references.

  3. Burner Rig Evaluation of Thermal Barrier Coating Systems for Nickel-Base Alloys

    NASA Technical Reports Server (NTRS)

    Gedwill, M. A.

    1981-01-01

    Eight plasma sprayed bond coatings were evaluated for their potential use with ZrO2-Y2O3 thermal barrier coatings (TECs) which are being developed for coal derived fuel fired gas turbines. Longer TBC lives in cyclic burner rig oxidation to 1050 C were achieved with the more oxidation resistant bond coatings. These were Ni-14.1Cr-13.4A1-0.10Ar, Ni-14.1C4-14.4Al-0.16Y, and Ni-15.8Cr-12.8Al-0.36Y on Rene 41. The TBC systems performed best when 0.015-cm thick bond coatings were employed that were sprayed at 20 kW using argon 3.5v/o hydrogen. Cycling had a more life limiting influence on the TBC than accumulated time at 1050 C.

  4. Ethical challenges in preparing for bioterrorism: barriers within the health care system.

    PubMed

    Wynia, Matthew K; Gostin, Lawrence O

    2004-07-01

    Preparedness for bioterrorism poses significant ethical challenges. Although public health ethics and preparedness have received attention recently, health care ethics must also be considered. In epidemics, the health care system assists public health in 3 tasks: detection, containment, and treatment. Detection might fail if all patients do not have access to care, or if physicians do not understand their obligation to report infectious diseases to public health authorities. Containment might fail if physicians view themselves only as advocates for individual patients, ignoring their social obligations as health professionals. Treatment might fail if physicians do not accept their professional duty to treat patients during epidemics. Each of these potential ethical barriers to preparedness must be addressed by physicians and society.

  5. Note: A novel dielectric barrier discharge system for generating stable patterns in wide range

    NASA Astrophysics Data System (ADS)

    Liu, Weibo; Wang, Yongjie; Zhang, Hao; Pan, Yuyang; Dong, Lifang

    2016-05-01

    We develop a novel dielectric barrier discharge (DBD) system with a meshed water electrode to generate stable square superlattice patterns (MSSP) in Ar/air mixture in a wide range of experimental environments. Discharge scenarios with the applied voltage increasing in the meshed DBD and ordinary DBD are presented respectively under the same experimental conditions. It is found that a square pattern and MSSP can be obtained stably and easily in meshed DBD, while no pattern emerges in ordinary DBD. MSSP can be formed when the Ar content is from 0% to 70%, and the corresponding applied voltage decreases with Ar content increasing. Results based on optical methods show that MSSP is generated by artificially designed electrodes together with nonlinear characteristics of DBD, which may account for why patterns in meshed DBD exist in a wide range.

  6. Mechanisms governing the interfacial delamination of thermal barrier coating system with double ceramic layers

    NASA Astrophysics Data System (ADS)

    Xu, Rong; Fan, Xueling; Wang, T. J.

    2016-05-01

    A systematic study of factors affecting the interfacial delamination of thermal barrier coating system (TBCs) with double ceramic layers (DCL) is presented. Crack driving forces for delaminations at two weak interfaces are examined. The results show that a thicker outermost ceramic layer can induce dramatic increase in crack driving force and make the interface between two ceramic coatings become more prone to delamination. The behavior is shown to be more prominent in TBCs with stiffer outmost coating. The thickness ratio of two ceramic layers is an important parameter for controlling the failure mechanisms and determining the lifetime of DCL TBCs under inservice condition. By accounting for the influences of thickness ratio of two ceramic layers and interfacial fracture toughnesses of two involved interfaces, the fracture mechanism map of DCL TBCs has been constructed, in which different failure mechanisms are identified. The results quanlitatively agree with the aviliable experimental data.

  7. Finite Element Modeling of the Different Failure Mechanisms of a Plasma Sprayed Thermal Barrier Coatings System

    NASA Astrophysics Data System (ADS)

    Ranjbar-Far, M.; Absi, J.; Mariaux, G.

    2012-12-01

    A new finite element model is used to investigate catastrophic failures of a thermal barrier coatings system due to crack propagation along the interfaces between the ceramic top-coat, thermally grown oxide, and bond-coat layers, as well as between the lamellas structure of the ceramic layer. The thermo-mechanical model is designed to take into account a non-homogenous temperature distribution and the effects of the residual stresses generated during the coating process. Crack propagation is simulated using the contact tool "Debond" present in the ABAQUS finite element code. Simulations are performed with a geometry corresponding to similar or dissimilar amplitudes of asperity, and for different thicknesses of the oxide layer. The numerical results have shown that crack evolution depends crucially on the ratio of the loading rate caused by growth and swelling of the oxide layer and also on the interface roughness obtained during the spraying of coatings.

  8. Enteral feeding and its impact on the gut immune system and intestinal mucosal barrier

    PubMed Central

    Kruszewski, Wiesław J.; Buczek, Tomasz

    2015-01-01

    Enteral feeding is the preferred method of nutritional therapy. Mucosal lack of contact with nutrients leads do lymphoid tissue atrophy, immune system functional decline, and intensification in bacterial translocation. Currently, it is assumed that microbiome is one of the body organs that has a significant impact on health. The composition of microbiome is not affected by age, sex, or place of residence, although it changes rapidly after diet modification. The composition of the microbiome is determined by enterotype, which is specific for each organism. It has a significant impact on the risk of diabetes, cancer, atherosclerosis, and other diseases. This review gathers data on interaction between gut-associated lymphoid tissue, mucosa-associated lymphoid tissue, microbiome, and the intestinal mucosal barrier. Usually, the information on the aforementioned is scattered in specialist-subject magazines such as gastroenterology, microbiology, genetics, biochemistry, and others. PMID:26557936

  9. Ethical Challenges in Preparing for Bioterrorism: Barriers Within the Health Care System

    PubMed Central

    Wynia, Matthew K.; Gostin, Lawrence O.

    2004-01-01

    Preparedness for bioterrorism poses significant ethical challenges. Although public health ethics and preparedness have received attention recently, health care ethics must also be considered. In epidemics, the health care system assists public health in 3 tasks: detection, containment, and treatment. Detection might fail if all patients do not have access to care, or if physicians do not understand their obligation to report infectious diseases to public health authorities. Containment might fail if physicians view themselves only as advocates for individual patients, ignoring their social obligations as health professionals. Treatment might fail if physicians do not accept their professional duty to treat patients during epidemics. Each of these potential ethical barriers to preparedness must be addressed by physicians and society. PMID:15226126

  10. A Resilient Condition Assessment Monitoring System

    SciTech Connect

    Humberto Garcia; Wen-Chiao Lin; Semyon M. Meerkov

    2012-08-01

    An architecture and supporting methods are presented for the implementation of a resilient condition assessment monitoring system that can adaptively accommodate both cyber and physical anomalies to a monitored system under observation. In particular, the architecture includes three layers: information, assessment, and sensor selection. The information layer estimates probability distributions of process variables based on sensor measurements and assessments of the quality of sensor data. Based on these estimates, the assessment layer then employs probabilistic reasoning methods to assess the plant health. The sensor selection layer selects sensors so that assessments of the plant condition can be made within desired time periods. Resilient features of the developed system are then illustrated by simulations of a simplified power plant model, where a large portion of the sensors are under attack.

  11. Thermally stable ZrN/Zr3N4 bilayered barrier system for through-Si-via process

    NASA Astrophysics Data System (ADS)

    Takeyama, Mayumi B.; Sato, Masaru; Noya, Atsushi

    2015-05-01

    We propose the use of a system composed of successively deposited ZrN (diffusion barrier)/Zr3N4 (insulating layer) barrier layers with the same constituents in the via-last through-Si-via (TSV) process. A preliminary examination of low-temperature-deposited Zr3N4 films by reactive sputtering reveals that the films show good characteristics as an insulating layer comparable to those of SiNx films prepared at low temperatures. The TSV model system of Cu/ZrN/Zr3N4/Si tolerates annealing at 500 °C for 60 min without any change in structure and/or configuration, showing good thermal stability as a candidate TSV barrier system.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  13. Network Systems Administration Needs Assessment.

    ERIC Educational Resources Information Center

    Lexington Community Coll., KY. Office of Institutional Research.

    In spring 1996, Lexington Community College (LCC) in Kentucky, conducted a survey to gather information on employment trends and educational needs in the field of network systems administration (NSA). NSA duties involve the installation and administration of network operating systems, applications software, and networking infrastructure;…

  14. Barriers to sustainable tuberculosis control in the Russian Federation health system.

    PubMed Central

    Atun, R. A.; Samyshkin, Y. A.; Drobniewski, F.; Skuratova, N. M.; Gusarova, G.; Kuznetsov, S. I.; Fedorin, I. M.; Coker, R. J.

    2005-01-01

    The Russian Federation has the eleventh highest tuberculosis burden in the world in terms of the total estimated number of new cases that occur each year. In 2003, 26% of the population was covered by the internationally recommended control strategy known as directly observed treatment (DOT) compared to an overall average of 61% among the 22 countries with the highest burden of tuberculosis. The Director-General of WHO has identified two necessary starting points for the scaling-up of interventions to control emerging infectious diseases. These are a comprehensive engagement with the health system and a strengthening of the health system. The success of programmes aimed at controlling infectious diseases is often determined by constraints posed by the health system. We analyse and evaluate the impact of the arrangements for delivering tuberculosis services in the Russian Federation, drawing on detailed analyses of barriers and incentives created by the organizational structures, and financing and provider-payment systems. We demonstrate that the systems offer few incentives to improve the efficiency of services or the effectiveness of tuberculosis control. Instead, the system encourages prolonged supervision through specialized outpatient departments in hospitals (known as dispensaries), multiple admissions to hospital and lengthy hospitalization. The implementation, and expansion and sustainability of WHO-approved methods of tuberculosis control in the Russian Federation are unlikely to be realized under the prevailing system of service delivery. This is because implementation does not take into account the wider context of the health system. In order for the control programme to be sustainable, the health system will need to be changed to enable services to be reconfigured so that incentives are created to reward improvements in efficiency and outcomes. PMID:15798846

  15. Assessment of crown-of-thorns skeletal elements in surface sediment of the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Henderson, R. A.

    1992-07-01

    A total of 1655 crown-of-thorns starfish skeletal elements were recovered from 237 surface sediment samples from Davies, Centipede, Myrmidon, Hope, Holbourne Island, 22 110, Gannet Cay and Lady Musgrave Island Reefs of the central and southern sectors of the Great Barrier Reef. Three categories of reef may be recognised on the incidence of Acanthaster planci skeletal elements in surface sediment from these and previously studied reefs: category A (abundant, >12 elements kg1-), category C (common, 3 8 elements kg-1) and category C (rare, 0 0.1 elements kg-1). These categories parallel estimates of crown-of-thorns populations in the period 1986 1990. “A” reefs have generally experienced high intensity outbreaks, “C” reefs less intense or perhaps less frequent outbreaks and “R” reefs have had little or no crown-of-thorns presence. The incidence of crown-of-thorns skeletal elements in surface sediment potentially provides an indication of population densities and outbreaks over a time scale of several decades. A perspective of contemporary crown-of-thorns incidence on the many reefs of the GBR lacking direct observational records may thereby be obtained. For Holbourne Island a comparison was made of element incidence in an area of known mass mortality induced by poisoning with a control area that was undisturbed. The incidence of A. planci skeletal elements is comparable in the two areas and similar to the incidence established for other reefs such as Green Island and John Brewer where high intensity outbreaks are known to have occurred. A direct relationship between high incidence of elements in surface sediment and mass mortality following outbreak events is indicated.

  16. GENETIC FACTORS ASSOCIATED WITH MATING SYSTEM CAUSE A PARTIAL REPRODUCTIVE BARRIER BETWEEN TWO PARAPATRIC SPECIES OF LEAVENWORTHIA (BRASSICACEAE)1

    PubMed Central

    Koelling, Vanessa A.; Mauricio, Rodney

    2010-01-01

    Reproductive barriers play a major role in the origin and maintenance of biodiversity by restricting gene flow between species. Although both pre- and postzygotic barriers often isolate species, prezygotic barriers are thought to contribute more to reproductive isolation. We investigated possible reproductive barriers between Leavenworthia alabamica and L. crassa, parapatric species with high morphological and ecological similarity and the ability to hybridize. Using greenhouse and field experiments, we tested for habitat isolation and genetic incompatibilities. From controlled crosses, we identified unilateral incompatibility (a partial prezygotic barrier associated with the self-incompatibility system), but no evidence of other genetic incompatibilities. We found a small reduction in pollen viability of F1 hybrids and early germination of F1, F2, and BC hybrids relative to L. alabamica and L. crassa in a common garden experiment, but the effect on fitness was not tested. Field studies of hybrid pollen viability and germination are needed to determine if they contribute to reproductive isolation. In a reciprocal transplant, we found no evidence of habitat isolation or reduced hybrid survival (from seedling to adult stage) or reproduction. These data suggest unilateral incompatibility partially reproductively isolates L. alabamica and L. crassa, but no other reproductive barriers could be detected. PMID:20526457

  17. Bridges and Barriers: Factors Influencing a Culture of Assessment in Academic Libraries

    ERIC Educational Resources Information Center

    Farkas, Meredith Gorran; Hinchliffe, Lisa Janicke; Houk, Amy Harris

    2015-01-01

    In an environment in which libraries need to demonstrate value, illustrating how the library contributes to student learning is critical. Gathering and analyzing data to tell the library's story as well as identify areas for improvement require commitment, time, effort, and resources--all components of a culture of assessment. This paper presents…

  18. C5a alters blood-brain barrier integrity in a human in vitro model of systemic lupus erythematosus.

    PubMed

    Mahajan, Supriya D; Parikh, Neil U; Woodruff, Trent M; Jarvis, James N; Lopez, Molly; Hennon, Teresa; Cunningham, Patrick; Quigg, Richard J; Schwartz, Stanley A; Alexander, Jessy J

    2015-09-01

    The blood-brain barrier (BBB) plays a crucial role in brain homeostasis, thereby maintaining the brain environment precise for optimal neuronal function. Its dysfunction is an intriguing complication of systemic lupus erythematosus (SLE). SLE is a systemic autoimmune disorder where neurological complications occur in 5-50% of cases and is associated with impaired BBB integrity. Complement activation occurs in SLE and is an important part of the clinical profile. Our earlier studies demonstrated that C5a generated by complement activation caused the loss of brain endothelial layer integrity in rodents. The goal of the current study was to determine the translational potential of these studies to a human system. To assess this, we used a two dimensional in vitro BBB model constructed using primary human brain microvascular endothelial cells and astroglial cells, which closely emulates the in vivo BBB allowing the assessment of BBB integrity. Increased permeability monitored by changes in transendothelial electrical resistance and cytoskeletal remodelling caused by actin fiber rearrangement were observed when the cells were exposed to lupus serum and C5a, similar to the observations in mice. In addition, our data show that C5a/C5aR1 signalling alters nuclear factor-κB translocation into nucleus and regulates the expression of the tight junction proteins, claudin-5 and zonula occludens 1 in this setting. Our results demonstrate for the first time that C5a regulates BBB integrity in a neuroinflammatory setting where it affects both endothelial and astroglial cells. In addition, we also demonstrate that our previous findings in a mouse model, were emulated in human cells in vitro, bringing the studies one step closer to understanding the translational potential of C5a/C5aR1 blockade as a promising therapeutic strategy in SLE and other neurodegenerative diseases.

  19. Safety assessment of the tritium recovery system

    SciTech Connect

    Not Available

    1994-09-01

    This Safety Assessment (SA) contains descriptions and evaluations of the environmental, health, and safety issues associated with the Tritium Recovery System (TRS) at the Pinellas Plant. It provides: 1. site and facility descriptions, 2. an overall description of the TRS and its operations, 3. an evaluation of the hazards associated with TRS operations, 4. descriptions and analyses of the adequacy of measures taken to eliminate, control, or mitigate identified hazards, and 5. assessment of potential accidents and their associated risks. This SA contains the results of safety evaluations of TRS operations, equipment, and supplied systems. The evaluations include, as appropriate, preliminary hazards listings, qualitative risk assessments, and quantitative risk assessments.

  20. Preliminary evaluation of predicted peak release rates from the engineered barrier system for a potential repository at Yucca Mountain, Nevada

    SciTech Connect

    Andrews, R.W.; McNeish, J.A.; Lee, J.H.

    1995-12-31

    Any potential repository for the ultimate disposal of the nation`s high-level radioactive wastes is subject to meeting post-closure regulatory requirements as specified by the NRC. Three NRC sub-system performance measures are relevant to the evaluation of the Yucca Mountain site and possible engineered barriers. These performance requirements are specified in 10 CFR 60. These include the substantially complete containment requirement, the engineered barrier system (EBS) release requirement, and the pre-waste emplacement groundwater travel time requirement. The present paper documents an initial evaluation of the peak EBS release rates. A number of key factors significantly impact the maximum release rate from the engineered barrier system. The authors have conducted four simulations to approximate the effects of delaying and spreading out the failure distribution that are based on different thermal loads and criteria for the initiation of aqueous corrosion. Using an assumed outer barrier of 10 cm and an inner barrier of 0.95 cm and the Stahl model for aqueous pitting corrosion, they have analyzed the EBS release rates for thermal loads of 28.5, 57 and 83 kW/Ac using temperature as the corrosion limiting factor and at 57 kW/Ac for saturation limiting the initiation of corrosion. The later had the earliest failures and the most rapid failure rates observed in the TSPA-1993 analyses so provides the upper bound on the release rates.

  1. An investigation of enhanced capability thermal barrier coating systems for diesel engine components

    NASA Technical Reports Server (NTRS)

    Holtzman, R. L.; Layne, J. L.; Schechter, B.

    1984-01-01

    Material systems and processes for the development of effective and durable thermal barriers for heavy duty diesel engines were investigated. Seven coating systems were evaluated for thermal conductivity, erosion resistance, corrosion/oxidation resistance, and thermal shock resistance. An advanced coating system based on plasma sprayed particle yttria stabilized zirconia (PS/HYSZ) was judged superior in these tests. The measured thermal conductivity of the selected coating was 0.893 W/m C at 371 C. The PS/HYSZ coating system was applied to the piston crown, fire deck and valves of a single cylinder low heat rejection diesel engine. The coated engine components were tested for 24 hr at power levels from 0.83 MPa to 1.17 MPa brake mean effective pressure. The component coatings survived the engine tests with a minimum of distress. The measured fire deck temperatures decreased 86 C (155 F) on the intake side and 42 C (75 F) on the exhaust side with the coating applied.

  2. Chlorine and carbon isotope measurements can help assessing the effectivenes of a zero valent iron barrier

    NASA Astrophysics Data System (ADS)

    Cretnik, S.; Audi, C.; Bernstein, A.; Palau, J.; Soler, A.; Elsner, M.

    2012-04-01

    Chlorinated aliphatic hydrocarbons (CAH's) such as trichloroethene (TCE), cis-dichloroethene (cis-DCE) and vinylchloride (VC) are extensively used in industrial applications. One of the most promising remediation techniques for CAH's in groundwater is their removal via abiotic reductive dechlorination using Zero Valent Iron (ZVI). This is applied for the treatment of contaminated sites by installing permeable reactive barriers (PRB). In this study, isotope fractionation of chlorinated ethylenes in transformation by cast iron has been investigated, because such types of iron are commonly used in PRBs. Batch experiments have been carried out in closed flasks, containing cast iron with aqueous solutions of TCE, cDCE and VC. These substrates and their respective products have been monitored by headspace samplings for their concentration (by GC-FID) and isotope fractionation of carbon and chlorine (by GC-IRMS). A decreasing reactivity trend was observed when compounds contain less chlorine atoms, with differences in rate constants of about one order of magnitude between each of the substances TCE > cDCE > VC. This resulted in the accumulation of products with fewer chlorine atoms. Therefore a similar observation can be expected if degradation in the field is incomplete, for example in the case of aged or improperly designed PRB. Pronounced carbon and chlorine isotope fractionation was measured for each of the compounds, and characteristic dual isotope plots (C, Cl) were obtained for TCE and cDCE. These results may serve as an important reference for the interpretation of isotope data from field sites, since stable isotope fractionation is widely recognized as robust indicator for such pollutant transformations. However, carbon isotope fractionation in a given parent compound may be caused by either abiotic or biotic degradation. In the field, it can therefore be difficult to delineate the contribution of abiotic transformation by PRB in the presence of ongoing

  3. Studies of the development of brain barrier systems to lipid insoluble molecules in fetal sheep.

    PubMed Central

    Dziegielewska, K M; Evans, C A; Malinowska, D H; Møllgård, K; Reynolds, J M; Reynolds, M L; Saunders, N R

    1979-01-01

    -brain barrier occurs via a transcellular route consisting of a system of tubulo-cisternal endoplasmic reticulum. Penetration via the choroid plexus appears to be the dominant route for penetration from blood into c.s.f. in the 60 day fetus. Images Plate 1 Plate 2 Plate 3 Plate 4 Plate 5 Plate 6 Plate 7 PMID:490348

  4. System Analysis and Risk Assessment System.

    2000-11-20

    Version 00 SARA4.16 is a program that allows the user to review the results of a Probabilistic Risk Assessment (PRA) and to perform limited sensitivity analysis on these results. This tool is intended to be used by a less technical oriented user and does not require the level of understanding of PRA concepts required by a full PRA analysis tool. With this program a user can review the information generated by a PRA analyst andmore » compare the results to those generated by making limited modifications to the data in the PRA. Also included in this program is the ability to graphically display the information stored in the database. This information includes event trees, fault trees, P&IDs and uncertainty distributions. SARA 4.16 is incorporated in the SAPHIRE 5.0 code package.« less

  5. Long-term climate change assessment study plan for the Hanford Site Permanent Isolation Barrier Development Program. Revision 1

    SciTech Connect

    Petersen, K.L.; Chatters, J.C.; Waugh, W.J.

    1993-05-01

    The Hanford Site Permanent Isolation Barrier Development Program (Barrier Development Program) was organized to develop the technology needed to provide an in-place disposal capability for low-level nuclear waste for the US Department of Energy at the Hanford Site in south-central Washington. The goal of the Barrier Development Program is to provide defensible evidence that final barrier design(s) will adequately control water infiltration, plant and animal intrusion, and wind and water erosion for a minimum of 1,000 yr; to isolate wastes from the accessible environment; and to use markers to warn inadvertent human intruders. Evidence for barrier performance will be obtained by conducting laboratory experiments, field tests, computer modeling, and other studies that establish confidence in the barrier`s ability to meet its 1,000-yr design life.

  6. Evolution of an intermittent lagoon-barrier system with rising sea level: observations and projections from the Muni-Pomadze lagoon, Ghana

    NASA Astrophysics Data System (ADS)

    Davies-Vollum, Sian

    2016-04-01

    Intermittently closed lagoon-barrier systems are a transitory environment between land and sea that are influenced by fluvial and marine processes as well as human activities. Fluvial processes dominate most of the time, when the barrier is closed. However, when the barrier is breached an ephemeral connection between the lagoon and the ocean develops and estuarine-like conditions ensue. As sea level rises, the evolution of these systems from intermittently closed to open is dependent on multiple processes including barrier breaching, fragmentation and overwashing. Human intervention, often to prevent flooding, also has an impact. The Muni-Pomadze lagoon in central Ghana is a small, intermittently closed lagoon-barrier system that supports a local fishing community. A beach-barrier separates the lagoon from the ocean, impounding river water and sediment behind it for most of the year. At the end of a rainy season the barrier may be breached, either naturally or by human intervention to prevent flooding of dwellings on the barrier. Field observation, digital mapping and GIS analysis of the shoreline has enabled an understanding of how the barrier is evolving with rising sea level. The shore face of the barrier has shifted landwards with an average retreat rate of 0.22 m/yr. Small washover fans, developed at low points along the lagoon side of the barrier have developed. However, aerial photos reveal that these fans have remained stable since 1972 (earliest available air photos). The small size and stability of these fans suggests that overwashing is not an important factor in the evolution of the barrier and that the barrier is being eroded rather not moving landward. Erosion is particularly prevalent at the breach end of the barrier with an average rate of loss of 3 metres per year and palm trees that were providing stability to the barrier have been washed away. Unconsolidated sands forming a transient, spit-like feature have replaced the stable barrier, which

  7. The surface cracking behavior in air plasma sprayed thermal barrier coating system incorporating interface roughness effect

    NASA Astrophysics Data System (ADS)

    Zhang, W. X.; Fan, X. L.; Wang, T. J.

    2011-11-01

    The objective of this work is to understand the effect of interface roughness on the strain energy release rate and surface cracking behavior in air plasma sprayed thermal barrier coating system. This is achieved by a parameter investigation of the interfacial shapes, in which the extended finite element method (XFEM) and periodic boundary condition are used. Predictions for the stress field and driving force of multiple surface cracks in the film/substrate system are presented. It is seen that the interface roughness has significant effects on the strain energy release rate, the interfacial stress distribution, and the crack propagation patterns. One can see the completely different distributions of stress and strain energy release rate in the regions of convex and concave asperities of the substrate. Variation of the interface asperity is responsible for the oscillatory characteristics of strain energy release rate, which can cause the local arrest of surface cracks. It is concluded that artificially created rough interface can enhance the durability of film/substrate system with multiple cracks.

  8. Pathways and hydrography in the Mesoamerican Barrier Reef System Part 2: Water masses and thermohaline structure

    NASA Astrophysics Data System (ADS)

    Carrillo, L.; Johns, E. M.; Smith, R. H.; Lamkin, J. T.; Largier, J. L.

    2016-06-01

    Hydrographic data from two oceanographic cruises conducted during March 2006 and January/February 2007 are used to investigate the thermohaline structure related to the observed circulation along the Mesoamerican Barrier Reef System (MBRS). From our observations we identify three water masses in the MBRS: the Caribbean Surface Water (CSW), North Atlantic Subtropical Underwater (SUW), and Tropical Atlantic Central Water (TACW). Little vertical structure in temperature is observed in the upper 100 m of the water column, but important differences are observed in the salinity distribution both horizontally and with depth. Freshwater inputs to the system from the mainland can be traced in the surface layer, with two possible sources: one from surface rivers located along the southern portion of the MBRS, and the other originating from an underground river system located along the northern portion of the MBRS. The thermohaline structure in the MBRS reflects the dynamics of the observed circulation. Uplifted isopycnals along most of the central and northern coastline of the MBRS reflect the effects of the strong geostrophic circulation flowing northward, i.e. the Yucatan Current. To the south along the MBRS, much weaker velocities are observed, with the Honduras Gyre dominating the flow in this region as presented during January/February 2007. These two regions are separated by onshore and divergent alongshore flow associated with the impingement of the Cayman Current on the shore and the MBRS.

  9. Effect of periodic surface cracks on the interfacial fracture of thermal barrier coating system

    NASA Astrophysics Data System (ADS)

    Fan, X. L.; Xu, R.; Zhang, W. X.; Wang, T. J.

    2012-10-01

    Periodic surface cracks and interfacial debonding in thermal barrier coating (TBC) system may be induced during cooling process. The objective of this work is to investigate the effect of periodic surface cracks on the interfacial fracture of TBC system. The finite element method (FEM) incorporating cohesive zone model is used in analysis. It is found that surface crack spacing has significant effect on the initiation and propagation of short interface crack. Three different regions are identified for describing the effect of surface crack spacing. In Region I the interface crack driving force is dramatically reduced due to high surface crack density. In this case, the initiation of interfacial delamination can be delayed. Region II applies as the surface crack spacing is moderate. Analysis of this transition zone brings to the definition of normalized critical surface crack spacing. Region III arises for sufficient large surface crack spacing. In this case, the interface crack driving force reaches a steady state, where the effects of adjacent surface cracks are relatively insignificant and can be ignored. It can be concluded that an appropriately high surface crack density can enhance the durability of TBC system.

  10. Design and Environmental Factors Contributing to the Failure of Thermal Barrier Coating Systems

    NASA Astrophysics Data System (ADS)

    Weeks, Matthew David

    Gas turbine engines are a staple of 21st century air and sea propulsion systems and are also a critical component in large-scale electricity generation. The hot-section components of these engines are protected by a complex ceramic and metal multi-layer coating called a thermal barrier coating (TBC) system. The failure of TBC systems occurs as a result of both thermo-chemical and thermo-mechanical degradation. This research involves exploring both of these mechanisms for two distinctly different issues. The United States Navy is currently making a push to implement the use of alternative fuels by 2012, but the use of these fuels (syngas, high hydrogen content, and alternatives to JP-8) presents significant materials durability challenges. Initial data suggests that high water vapor levels, high sulfur concentrations, and ash deposits from fuel impurities lead to unique, and severe, degradation modes. This research is aimed at addressing the effects of differing combustion environment characteristics on the corrosion and oxidation of TBC systems. On the industrial front, there is a constant driver to better understand and predict coating failure, particularly in air-plasma sprayed (APS) TBC systems. The morphology of the metal-ceramic interface is known to play a key role in the generation of compressive and tensile stresses that eventually cause coating failure in typical engine environments. Experimental evidence and field experience have shown that a tortuous interface is generally beneficial to coating lifetime. Nevertheless, for the past 40 years engineers have struggled to find a functional correlation between BC topology and coating system lifetime. This document also addresses the progress that has been made toward the establishment of this functional correlation.

  11. Systemic barriers accessing HIV treatment among people who inject drugs in Russia: a qualitative study

    PubMed Central

    Sarang, Anya; Rhodes, Tim; Sheon, Nicolas

    2013-01-01

    Achieving ‘universal access’ to antiretroviral HIV treatment (ART) in lower income and transitional settings is a global target. Yet, access to ART is shaped by local social condition and is by no means universal. Qualitative studies are ideally suited to describing how access to ART is socially situated. We explored systemic barriers to accessing ART among people who inject drugs (PWID) in a Russian city (Ekaterinburg) with a large burden of HIV treatment demand. We undertook 42 in-depth qualitative interviews with people living with HIV with current or recent experience of injecting drug use. Accounts were analysed thematically, and supplemented here with an illustrative case study. Three core themes were identified: ‘labyrinthine bureaucracy’ governing access to ART; a ‘system Catch 22’ created by an expectation that access to ART was conditional upon treated drug use in a setting of limited drug treatment opportunity; and ‘system verticalization’, where a lack of integration across HIV, tuberculosis (TB) and drug treatment compromised access to ART. Taken together, we find that systemic factors play a key role in shaping access to ART with the potential adverse effects of reproducing treatment initiation delay and disengagement from treatment. We argue that meso-level systemic factors affecting access to ART for PWID interact with wider macro-level structural forces, including those related to drug treatment policy and the social marginalization of PWID. We note the urgent need for systemic and structural changes to improve access to ART for PWID in this setting, including to simplify bureaucratic procedures, foster integrated HIV, TB and drug treatment services, and advocate for drug treatment policy reform. PMID:23197431

  12. Electrical method for detection of endothelial cell shape change in real time: assessment of endothelial barrier function.

    PubMed Central

    Tiruppathi, C; Malik, A B; Del Vecchio, P J; Keese, C R; Giaever, I

    1992-01-01

    We have developed an electrical method to study endothelial cell shape changes in real time in order to examine the mechanisms of alterations in the endothelial barrier function. Endothelial shape changes were quantified by using a monolayer of endothelial cells grown on a small (10(-3) cm2) evaporated gold electrode and measuring the changes in electrical impedance. Bovine pulmonary microvessel endothelial cells and bovine pulmonary artery endothelial cells were used to study the effects of alpha-thrombin on cell-shape dynamics by the impedance measurement. alpha-Thrombin produced a dose-dependent decrease in impedance that occurred within 0.5 min in both cell types, indicative of retraction of endothelial cells and widening of interendothelial junctions because of "rounding up" of the cells. The alpha-thrombin-induced decrease in impedance persisted for approximately 2 hr, after which the value recovered to basal levels. Pretreatment of endothelial cells with the protein kinase C inhibitor, calphostin C, or with 8-bromoadenosine 3',5'-cyclic monophosphate prevented the decreased impedance, suggesting that the endothelial cell change is modulated by activation of second-messenger pathways. The alpha-thrombin-induced decrease in impedance was in agreement with the previously observed increases in transendothelial albumin permeability and evidence of formation of intercellular gaps after alpha-thrombin challenge. The impedance measurement may be a valuable in vitro method for the assessment of mechanisms of decreased endothelial barrier function occurring with inflammatory mediators. Since the rapidly occurring changes in endothelial cell shape in response to mediators such as thrombin are mediated activation of second-messenger pathways, the ability to monitor endothelial cell dynamics in real time may provide insights into the signal-transduction events mediating the increased endothelial permeability. PMID:1518814

  13. A Novel Human Autonomy Assessment System

    PubMed Central

    Munstermann, Marco; Stevens, Torsten; Luther, Wolfram

    2012-01-01

    This article presents a novel human autonomy assessment system for generating context and discovering the behaviors of older people who use ambulant services. Our goal is to assist caregivers in assessing possibly abnormal health conditions in their clients concerning their level of autonomy, thus enabling caregivers to take countermeasures as soon as possible. PMID:22969374

  14. In situ retreival of contaminants or other substances using a barrier system and leaching solutions and components, processes and methods relating thereto

    DOEpatents

    Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

    2005-06-28

    Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

  15. Permeability assessment of the focused ultrasound-induced blood-brain barrier opening using dynamic contrast-enhanced MRI

    NASA Astrophysics Data System (ADS)

    Vlachos, F.; Tung, Y.-S.; Konofagou, E. E.

    2010-09-01

    Focused ultrasound (FUS) in conjunction with microbubbles has been shown to successfully open the blood-brain barrier (BBB) in the mouse brain. In this study, we compute the BBB permeability after opening in vivo. The spatial permeability of the BBB-opened region was assessed using dynamic contrast-enhanced MRI (DCE-MRI). The DCE-MR images were post-processed using the general kinetic model (GKM) and the reference region model (RRM). Permeability maps were generated and the Ktrans values were calculated for a predefined volume of interest in the sonicated and the control area for each mouse. The results demonstrated that Ktrans in the BBB-opened region (0.02 ± 0.0123 for GKM and 0.03 ± 0.0167 min-1 for RRM) was at least two orders of magnitude higher when compared to the contra-lateral (control) side (0 and 8.5 × 10-4 ± 12 × 10-4 min-1, respectively). The permeability values obtained with the two models showed statistically significant agreement and excellent correlation (R2 = 0.97). At histological examination, it was concluded that no macroscopic damage was induced. This study thus constitutes the first permeability assessment of FUS-induced BBB opening using DCE-MRI, supporting the fact that the aforementioned technique may constitute a safe, non-invasive and efficacious drug delivery method.

  16. Scientific method, adversarial system, and technology assessment

    NASA Technical Reports Server (NTRS)

    Mayo, L. H.

    1975-01-01

    A basic framework is provided for the consideration of the purposes and techniques of scientific method and adversarial systems. Similarities and differences in these two techniques of inquiry are considered with reference to their relevance in the performance of assessments.

  17. Advanced vehicle systems assessment. Volume 5: Appendices

    NASA Technical Reports Server (NTRS)

    Hardy, K.

    1985-01-01

    An appendix to the systems assessment for the electric hybrid vehicle project is presented. Included are battery design, battery cost, aluminum vehicle construction, IBM PC computer programs and battery discharge models.

  18. SCIENCE BRIEF: CONDITION ASSESSMENT OF COLLECTION SYSTEMS

    EPA Science Inventory

    To assess the condition of a collection system, data and information are gathered through observation, direct inspection, investigation, and indirect monitoring and reporting. An analysis of the data and information helps determine the structural, operational, and performance sta...

  19. AVNG SYSTEM SOFTWARE - ATTRIBUTE VERIFICATION SYSTEM WITH INFORMATION BARRIERS FOR MASS AND ISOTOPICS MEASUREMENTS

    SciTech Connect

    Modenov, A; Bulatov, M; Livke, A; Morkin, A; Razinkov, S; Safronov, S; Elmont, T; Langner, D; MacArthur, D; Mayo, D; Smith, M; Luke, S J

    2005-06-10

    This report describes the software development for the plutonium attribute verification system--AVNG. A brief synopsis of the technical solution for the measurement system is presented. The main tasks for the software development that is underway are formulated. The development tasks are shown in software structural flowcharts, measurement system state diagram and a description of the software. The current status of the AVNG software development is elucidated.

  20. Barriers to Initiating and Continuing Mental Health Treatment Among Soldiers in the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

    PubMed

    Naifeh, James A; Colpe, Lisa J; Aliaga, Pablo A; Sampson, Nancy A; Heeringa, Steven G; Stein, Murray B; Ursano, Robert J; Fullerton, Carol S; Nock, Matthew K; Schoenbaum, Michael; Zaslavsky, Alan M; Kessler, Ronald C

    2016-09-01

    U.S. Army soldiers with mental disorders report a variety of barriers to initiating and continuing treatment. Improved understanding of these barriers can help direct mental health services to soldiers in need. A representative sample of 5,428 nondeployed Regular Army soldiers participating in the Army Study to Assess Risk and Resilience in Servicemembers completed a self-administered questionnaire and consented to linking self-administered questionnaire data with administrative records. We examined reported treatment barriers (perceived need, structural reasons, attitudinal reasons) among respondents with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, mental disorders who either did not seek treatment in the past year (n = 744) or discontinued treatment (n = 145). About 82.4% of soldiers who did not initiate treatment and 69.5% of those who discontinued treatment endorsed at least two barriers; 69.8% of never-treated soldiers reported no perceived need. Attitudinal reasons were cited more frequently than structural reasons among never-treated soldiers with perceived need (80.7% vs. 62.7%) and those who discontinued treatment (71.0% vs. 37.8%). Multivariate associations with sociodemographic, Army career, and mental health predictors varied across barrier categories. These findings suggest most soldiers with mental disorders do not believe they need treatment and those who do typically face multiple attitudinal and, to a lesser extent, structural barriers.

  1. Barriers to Initiating and Continuing Mental Health Treatment Among Soldiers in the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS).

    PubMed

    Naifeh, James A; Colpe, Lisa J; Aliaga, Pablo A; Sampson, Nancy A; Heeringa, Steven G; Stein, Murray B; Ursano, Robert J; Fullerton, Carol S; Nock, Matthew K; Schoenbaum, Michael; Zaslavsky, Alan M; Kessler, Ronald C

    2016-09-01

    U.S. Army soldiers with mental disorders report a variety of barriers to initiating and continuing treatment. Improved understanding of these barriers can help direct mental health services to soldiers in need. A representative sample of 5,428 nondeployed Regular Army soldiers participating in the Army Study to Assess Risk and Resilience in Servicemembers completed a self-administered questionnaire and consented to linking self-administered questionnaire data with administrative records. We examined reported treatment barriers (perceived need, structural reasons, attitudinal reasons) among respondents with current Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, mental disorders who either did not seek treatment in the past year (n = 744) or discontinued treatment (n = 145). About 82.4% of soldiers who did not initiate treatment and 69.5% of those who discontinued treatment endorsed at least two barriers; 69.8% of never-treated soldiers reported no perceived need. Attitudinal reasons were cited more frequently than structural reasons among never-treated soldiers with perceived need (80.7% vs. 62.7%) and those who discontinued treatment (71.0% vs. 37.8%). Multivariate associations with sociodemographic, Army career, and mental health predictors varied across barrier categories. These findings suggest most soldiers with mental disorders do not believe they need treatment and those who do typically face multiple attitudinal and, to a lesser extent, structural barriers. PMID:27612348

  2. Assessing barriers and facilitators of implementing an integrated HIV prevention and property rights program in Western Kenya.

    PubMed

    Lu, Tiffany; Zwicker, Lindsey; Kwena, Zachary; Bukusi, Elizabeth; Mwaura-Muiru, Esther; Dworkin, Shari L

    2013-04-01

    Despite the recognized need for structural HIV prevention interventions, few scientific programs have integrated women's property and inheritance rights with HIV prevention and treatment. The current study focused on a community-led land and property rights intervention that was implemented in two rural areas of Western Kenya with high HIV prevalence rates (24-30%). The program was designed to respond to women's property rights violations in order to reduce HIV risk at the local level. Through in-depth interviews with twenty program leaders, we identified several facilitators to program implementation, including the leadership of home-based HIV caregivers and involvement of traditional leaders in mediating property rights disputes. We also identified the voluntary basis of the intervention and its lack of integration with the formal justice system as implementation barriers. Our findings can guide future research and design of structural HIV prevention strategies that integrate women's economic empowerment through property and inheritance rights.

  3. Oxygen Compatibility Assessment of Components and Systems

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel; Sparks, Kyle

    2010-01-01

    Fire hazards are inherent in oxygen systems and a storied history of fires in rocket engine propulsion components exists. To detect and mitigate these fire hazards requires careful, detailed, and thorough analyses applied during the design process. The oxygen compatibility assessment (OCA) process designed by NASA Johnson Space Center (JSC) White Sands Test Facility (WSTF) can be used to determine the presence of fire hazards in oxygen systems and the likelihood of a fire. This process may be used as both a design guide and during the approval process to ensure proper design features and material selection. The procedure for performing an OCA is a structured step-by-step process to determine the most severe operating conditions; assess the flammability of the system materials at the use conditions; evaluate the presence and efficacy of ignition mechanisms; assess the potential for a fire to breach the system; and determine the reaction effect (the potential loss of life, mission, and system functionality as the result of a fire). This process should be performed for each component in a system. The results of each component assessment, and the overall system assessment, should be recorded in a report that can be used in the short term to communicate hazards and their mitigation and to aid in system/component development and, in the long term, to solve anomalies that occur during engine testing and operation.

  4. Integrated Assessment Systems for Chemical Warfare Material

    SciTech Connect

    A. M. Snyder; D. A. Verrill; G. L. Thinnes; K. D. Watts; R. J. McMorland

    1999-05-27

    The US Army must respond to a variety of situations involving suspect discovered, recovered, stored, and buried chemical warfare materiel (CWM). In some cases, the identity of the fill materiel and the status of the fusing and firing train cannot be visually determined due to aging of the container, or because the item is contained in an over-pack. In these cases, non-intrusive assessments are required to provide information to allow safe handling, storage, and disposal of the materiel. This paper will provide an overview of the integrated mobile and facility-based CWM assessment system prototypes that have been, and are being developed, at the Idaho National Engineering and Environmental Laboratory (INEEL) for the US Army Non-Stockpile Chemical Materiel Project. In addition, this paper will discuss advanced sensors being developed to enhance the capability of the existing and future assessment systems. The Phase I Mobile Munitions Assessment System (MMAS) is currently being used by the Army's Technical Escort Unit (TEU) at Dugway Proving Ground, Utah. This system includes equipment for non-intrusively identifying the munitions fill materiel and for assessing the condition and stability of the fuzes, firing trains, and other potential safety hazards. The system provides a self-contained, integrated command post including an on-board computer system, communications equipment, video and photographic equipment, weather monitoring equipment, and miscellaneous safety-related equipment. The Phase II MMAS is currently being tested and qualified for use by the INEEL and the US Army. The Phase II system contains several new assessment systems that significantly enhance the ability to assess CWM. A facility-based munitions assessment system prototype is being developed for the assessment of CWM stored in igloos at Pine Bluff Arsenal, Arkansas. This system is currently in the design and fabrication stages. Numerous CWM advanced sensors are being developed and tested, and

  5. Quadruplex digital flight control system assessment

    NASA Technical Reports Server (NTRS)

    Mulcare, D. B.; Downing, L. E.; Smith, M. K.

    1988-01-01

    Described are the development and validation of a double fail-operational digital flight control system architecture for critical pitch axis functions. Architectural tradeoffs are assessed, system simulator modifications are described, and demonstration testing results are critiqued. Assessment tools and their application are also illustrated. Ultimately, the vital role of system simulation, tailored to digital mechanization attributes, is shown to be essential to validating the airworthiness of full-time critical functions such as augmented fly-by-wire systems for relaxed static stability airplanes.

  6. Overcoming the Meter Barrier and The Formation of Systems with Tightly-packed Inner Planets (STIPs)

    NASA Astrophysics Data System (ADS)

    Boley, Aaron C.; Morris, Melissa A.; Ford, Eric B.

    2014-11-01

    The Kepler space mission has revealed numerous planetary types and systems, shaping our understanding of planet formation. Among the quickly-growing data is a subclass of multi-planet configurations referred to as Systems with Tightly-packed Inner Planets (STIPs). Their large abundance (>10% of stars) suggests that they are one of the principal outcomes of planet formation. The prototype STIP is Kepler-11, which hosts six known transiting planets, five of which have measured masses in the super-Earth and mini-Neptune regimes. The known planetary orbits in this system are spaced between a=0.09 and 0.47 AU, with small eccentricities and mutual inclinations. The lack of low-order mean motion resonances among planets in STIPs suggests that migration may have not played a dominant role in placing all of these planets on short orbital periods. While the formation of massive planetary systems on the hot side of the water ice line may be difficult to reconcile under the current paradigm of planet formation, we must explore whether many STIP planets formed by and large in situ. We discuss an overlooked mechanism that may allow the in situ formation of planetary systems on very short orbital periods. As solids spiral inward due to aerodynamic drag, they will enter disk regions that are characterized by high temperatures, densities, and pressures. High partial pressures of rock vapor can reduce net evaporation of incoming material, which could promote collisions between partially molten solids, allowing rapid growth and overcoming the classic meter barrier.

  7. Feasibility study of a single-element transcranial focused ultrasound system for blood-brain barrier opening

    NASA Astrophysics Data System (ADS)

    Marquet, Fabrice; Tung, Yao-Sheng; Teichert, Tobias; Ferrera, Vincent P.; Konofagou, Elisa E.

    2012-10-01

    The blood-brain barrier (BBB) is a specialized vascular system that impedes entry of all large and the vast majority of small molecules including the most potent CNS disease therapeutic agents from entering from the lumen into the brain parenchyma. Microbubble-enhanced, focused ultrasound (ME-FUS) has been previously shown to disrupt noninvasively, selectively, and transiently the BBB in small animals in vivo. The study addresses the focusing properties of single-element transducers at intermediate frequencies (500 kHz) through primate and human skulls, targeting clinically relevant targets extracted from 3D brain atlases such as the hippocampus and the basal ganglia, which are typically affected by early Alzheimer's and Parkinson's disease, respectively. A preliminary in vivo study was performed to study the frequency dependence of BBB opening parameters in mice. Then, feasibility of transcranial ME-FUS BBB opening in non-human primates was demonstrated with subsequent BBB recovery. Sonications were combined with two different types of microbubbles (custom made 4-5 μm and Definity®). 3T MRI was used to confirm the BBB disruption and to assess brain damage.

  8. Systemic delivery of blood-brain barrier-targeted polymeric nanoparticles enhances delivery to brain tissue.

    PubMed

    Saucier-Sawyer, Jennifer K; Deng, Yang; Seo, Young-Eun; Cheng, Christopher J; Zhang, Junwei; Quijano, Elias; Saltzman, W Mark

    2015-01-01

    Delivery of therapeutic agents to the central nervous system is a significant challenge, hindering progress in the treatment of diseases such as glioblastoma. Due to the presence of the blood-brain barrier (BBB), therapeutic agents do not readily transverse the brain endothelium to enter the parenchyma. Previous reports suggest that surface modification of polymer nanoparticles (NPs) can improve their ability to cross the BBB, but it is unclear whether the observed enhancements in transport are large enough to enhance therapy. In this study, we synthesized two degradable polymer NP systems surface-modified with ligands previously suggested to improve BBB transport, and tested their ability to cross the BBB after intravenous injection in mice. All the NP preparations were able to cross the BBB, although generally in low amounts (<0.5% of the injected dose), which was consistent with prior reports. One NP produced significantly higher brain uptake (∼0.8% of the injected dose): a block copolymer of polylactic acid and hyperbranched polyglycerol, surface modified with adenosine (PLA-HPG-Ad). PLA-HPG-Ad NPs provided controlled release of camptothecin, killing U87 glioma cells in culture. When administered intravenously in mice with intracranial U87 tumors, they failed to increase survival. These results suggest that enhancing NP transport across the BBB does not necessarily yield proportional pharmacological effects.

  9. Overcoming Relationship-Initiation Barriers: The Impact of a Computer-Dating System on Sex Role, Shyness, and Appearance Inhibitions.

    ERIC Educational Resources Information Center

    Scharlott, Bradford W.; Christ, William G.

    1995-01-01

    A survey of the users of an online computer-mediated matchmaking service showed that their communication patterns and objectives varied by their sex, shyness level, and appearance. Intrinsic aspects of this system helped some users overcome relationship-initiation barriers rooted in sex role, shyness, and appearance inhibitions. (Author)

  10. Advanced turbine systems - research and development of thermal barrier coatings technology: 3rd bimonthly report, April 1996

    SciTech Connect

    1996-04-01

    Objective of the ATS program is the development of ultra-highly efficient, environmentally superior, and cost-competitive gas turbine systems, using thermal barrier coatings. These coatings should be stable in the thermal and corrosive environments of the industrial engine for up to 2500 hours. Phase II (development) is current.

  11. Advanced turbine systems - research and development of thermal barrier coatings technology: 2nd bimonthly report, February 1996

    SciTech Connect

    1996-02-01

    Objective of the ATS program is the development of ultra-highly efficient, environmentally superior, and cost-competitive gas turbine systems, with long, less cyclic operating profiles than aircraft gas turbine engines. Durability and performance demands of ATS can be achieved by means of thermal barrier coatings. Phase I (program plan) is complete. Phase II is in progress.

  12. A qualitative study to assess community barriers to malaria mass drug administration trials in the Gambia

    PubMed Central

    2014-01-01

    Background Mass drug administration (MDA) is a strategy widely used in the control of human parasitic diseases but has been rarely attempted with malaria, the most common and dangerous parasitic disease in humans. MDA is an intervention strategy that involves simultaneously dispensing treatment to an entire population in a given geographic area. With some areas in sub-Saharan Africa documenting a decline in malaria transmission, the feasibility of MDA to further reduce malaria transmission is being considered. Understanding community perceptions of such an activity is vitally important for the design of the study and gaining the support of participants in order to maximize compliance and adherence. Methods A qualitative study to assess factors likely to influence community acceptance of MDA in the seasonal and low malaria transmission setting of The Gambia was conducted. Using in-depth interviews, the perceptions, knowledge and attitudes of medical personnel and community members who have undergone MDA trials in The Gambia were investigated. Results Several major themes emerged, namely: 1) the importance of timing of rounds of MDA doses for maximum participation; 2) the need to educate the target population with accurate information on the procedures, drug regimen, and possible side effects to enhance adherence; 3) the need for continuous sensitization meetings to maintain and increase uptake of MDA; and, 4) the importance for defining roles in the delivery and assessment of MDA, including existing healthcare structures. Discussion To increase the likelihood of participation in MDA trials in this setting, activities should be undertaken just before and during the rainy season when community members are less mobile. Importantly, fears regarding blood sampling and side effects of the drug regimen need to be addressed prior to the start of the trial and repeated throughout the study period. Accurate and frequent communication is essential, and village leaders should

  13. Assessing barriers to health insurance and threats to equity in comparative perspective: The Health Insurance Access Database

    PubMed Central

    2012-01-01

    Background Typologies traditionally used for international comparisons of health systems often conflate many system characteristics. To capture policy changes over time and by service in health systems regulation of public and private insurance, we propose a database containing explicit, standardized indicators of policy instruments. Methods The Health Insurance Access Database (HIAD) will collect policy information for ten OECD countries, over a range of eight health services, from 1990–2010. Policy indicators were selected through a comprehensive literature review which identified policy instruments most likely to constitute barriers to health insurance, thus potentially posing a threat to equity. As data collection is still underway, we present here the theoretical bases and methodology adopted, with a focus on the rationale underpinning the study instruments. Results These harmonized data will allow the capture of policy changes in health systems regulation of public and private insurance over time and by service. The standardization process will permit international comparisons of systems’ performance with regards to health insurance access and equity. Conclusion This research will inform and feed the current debate on the future of health care in developed countries and on the role of the private sector in these changes. PMID:22551599

  14. Combined heat and power systems: economic and policy barriers to growth

    PubMed Central

    2012-01-01

    Background Combined Heat and Power (CHP) systems can provide a range of benefits to users with regards to efficiency, reliability, costs and environmental impact. Furthermore, increasing the amount of electricity generated by CHP systems in the United States has been identified as having significant potential for impressive economic and environmental outcomes on a national scale. Given the benefits from increasing the adoption of CHP technologies, there is value in improving our understanding of how desired increases in CHP adoption can be best achieved. These obstacles are currently understood to stem from regulatory as well as economic and technological barriers. In our research, we answer the following questions: Given the current policy and economic environment facing the CHP industry, what changes need to take place in this space in order for CHP systems to be competitive in the energy market? Methods We focus our analysis primarily on Combined Heat and Power Systems that use natural gas turbines. Our analysis takes a two-pronged approach. We first conduct a statistical analysis of the impact of state policies on increases in electricity generated from CHP system. Second, we conduct a Cost-Benefit analysis to determine in which circumstances funding incentives are necessary to make CHP technologies cost-competitive. Results Our policy analysis shows that regulatory improvements do not explain the growth in adoption of CHP technologies but hold the potential to encourage increases in electricity generated from CHP system in small-scale applications. Our Cost-Benefit analysis shows that CHP systems are only cost competitive in large-scale applications and that funding incentives would be necessary to make CHP technology cost-competitive in small-scale applications. Conclusion From the synthesis of these analyses we conclude that because large-scale applications of natural gas turbines are already cost-competitive, policy initiatives aimed at a CHP market

  15. New environmental barrier coating system on carbon-fiber reinforced silicon carbide composites

    NASA Astrophysics Data System (ADS)

    Latzel, S.; Vaßen, R.; Stöver, D.

    2005-06-01

    Carbon-fiber-reinforced silicon carbide composites (C/SiC) are promising materials for high-temperature, light weight structural components. However, a protective coating and environmental barrier coating (EBC) are necessary to prevent the oxidation of the carbon and the reaction of the formed silica scale with water vapor. Current EBC systems use multiple layers, each serving unique requirements. However, any mismatch in the coefficients of thermal expansion (CTE) creates internal stresses and might lead to crack formation. In this case, oxygen and water vapor penetrate through the EBC, reducing the lifetime of the component. Mullite (Al6Si2O13) is used in many known EBC systems on silicon-based ceramics either as an EBC itself or as a bondcoat. Due to its low CTE and its sufficient thermal cycling behavior, mullite was chosen in this investigation as a first layer. As mullite suffers loss of SiO2 when exposed to water vapor at high temperatures, an additional protective top coat is needed to complete the EBC system. Different oxides were evaluated to serve as top coat, especially high-temperature oxides with low coefficients of thermal expansion (LCTE). An EBC containing mullite as bondcoat and the LCTE oxide La2Hf2O7 as a top coat is proposed. Both layers were applied via atmospheric plasma spraying. In this paper, results of the influence of processing conditions on the microstructure of single mullite and LCTE oxide layers as well as mullite/LCTE oxide systems are presented. Special emphasis was directed toward the crystallinity of the mullite layer and, in the top layer, toward low porosity and reduced crack density.

  16. Novel targeted approach to better understand how natural structural barriers govern carotenoid in vitro bioaccessibility in vegetable-based systems.

    PubMed

    Palmero, Paola; Lemmens, Lien; Ribas-Agustí, Albert; Sosa, Carola; Met, Kristof; de Dieu Umutoni, Jean; Hendrickx, Marc; Van Loey, Ann

    2013-12-01

    An experimental approach, allowing us to understand the effect of natural structural barriers (cell walls, chromoplast substructures) on carotenoid bioaccessibility, was developed. Different fractions with different levels of carotenoid bio-encapsulation (carotenoid-enriched oil, chromoplasts, small cell clusters, and large cell clusters) were isolated from different types of carrots and tomatoes. An in vitro method was used to determine carotenoid bioaccessibility. In the present work, a significant decrease in carotenoid in vitro bioaccessibility could be observed with an increasing level of bio-encapsulation. Differences in cell wall material and chromoplast substructure between matrices influenced carotenoid release and inclusion in micelles. For carrots, cell walls and chromoplast substructure were important barriers for carotenoid bioaccessibility while, in tomatoes, the chromoplast substructure represented the most important barrier governing bioaccessibility. The highest increase in carotenoid bioaccessibility, for all matrices, was obtained after transferring carotenoids into the oil phase, a system lacking cell walls and chromoplast substructures that could hamper carotenoid release.

  17. Achieving and Sustaining Automated Health Data Linkages for Learning Systems: Barriers and Solutions

    PubMed Central

    Van Eaton, Erik G.; Devlin, Allison B.; Devine, Emily Beth; Flum, David R.; Tarczy-Hornoch, Peter

    2014-01-01

    Introduction: Delivering more appropriate, safer, and highly effective health care is the goal of a learning health care system. The Agency for Healthcare Research and Quality (AHRQ) funded enhanced registry projects: (1) to create and analyze valid data for comparative effectiveness research (CER); and (2) to enhance the ability to monitor and advance clinical quality improvement (QI). This case report describes barriers and solutions from one state-wide enhanced registry project. Methods: The Comparative Effectiveness Research and Translation Network (CERTAIN) deployed the commercially available Amalga Unified Intelligence System™ (Amalga) as a central data repository to enhance an existing QI registry (the Automation Project). An eight-step implementation process included hospital recruitment, technical electronic health record (EHR) review, hospital-specific interface planning, data ingestion, and validation. Data ownership and security protocols were established, along with formal methods to separate data management for QI purposes and research purposes. Sustainability would come from lowered chart review costs and the hospital’s desire to invest in the infrastructure after trying it. Findings: CERTAIN approached 19 hospitals in Washington State operating within 12 unaffiliated health care systems for the Automation Project. Five of the 19 completed all implementation steps. Four hospitals did not participate due to lack of perceived institutional value. Ten hospitals did not participate because their information technology (IT) departments were oversubscribed (e.g., too busy with Meaningful Use upgrades). One organization representing 22 additional hospitals expressed interest, but was unable to overcome data governance barriers in time. Questions about data use for QI versus research were resolved in a widely adopted project framework. Hospitals restricted data delivery to a subset of patients, introducing substantial technical challenges. Overcoming

  18. Sub-Barrier Fusion in the HI + 208Pb Systems and Nuclear Potentials for Cluster Decay

    SciTech Connect

    Sagaidak, R.N.; Tretyakova, S.P.; Khlebnikov, S.V.; Ogloblin, A.A.; Rowley, N.

    2005-11-21

    Near-barrier fusion excitation functions for the 12,14C, 16,18O + 208Pb reactions have been analyzed in the framework of the barrier-passing model using different forms of the nuclear potential and the phenomenology of a fluctuating barrier. The best-fit fusion potentials were used to estimate cluster decay probabilities from the corresponding ground states of Ra and Th, i.e., for the inverse decay process. The analysis supports the 'alpha-decay-like' scenario for carbon and oxygen emission from these nuclei.

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

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming

    2015-01-01

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

  20. Transcranial Cavitation Detection in Primates during Blood-Brain Barrier Opening – A Performance Assessment Study

    PubMed Central

    Wu, Shih-Ying; Tung, Yao-Sheng; Marquet, Fabrice; Downs, Matthew Eric; Sanchez, Carlos Sierra; Chen, Cherry Chen; Ferrera, Vincent

    2014-01-01

    Focused ultrasound (FUS) has been shown promise in treating the brain locally and noninvasively. Transcranial passive cavitation detection (PCD) provides methodology of monitoring the treatment in real time, while the skull effects remain a major challenge for its translation to the clinic. In this study, we investigated the sensitivity, reliability, and limitations of PCD through primate (macaque and human) skulls in vitro. The results were further correlated with the in vivo macaque studies including the transcranial PCD calibration and real-time monitoring of BBB opening, with magnetic resonance imaging assessing the opening and safety. The stable cavitation doses using harmonics (SCDh) and ultraharmonics (SCDu), the inertial cavitation dose (ICD), and the cavitation signal-to-noise ratio (SNR) were quantified based on the PCD signals. Results showed that through the macaque skull the pressure threshold for detecting the SCDh remained the same as without the skull in place, while it increased for the SCDu and ICD; through the human skull, it increased for all cavitation doses. The transcranial PCD was found reliable both in vitro and in vivo when the transcranial cavitation SNR exceeded the 1-dB detection limit through the in vitro macaque (attenuation: 4.92 dB/mm) and human (attenuation: 7.33 dB/mm) skull. In addition, using long pulses enabled reliable PCD monitoring and facilitate BBB opening at low pressures. The in vivo results showed that the SCDh became detectable at pressures as low as 100 kPa; the ICD, at 250 kPa while it could occur at lower pressures; the SCDu, at 700 kPa and was less reliable at lower pressures. Real-time monitoring of PCD was further implemented during BBB opening, with successful and safe opening achieved at 250–600 kPa in both the thalamus and the putamen. In conclusion, this study shows that transcranial PCD in macaques in vitro and in vivo as well as humans in vitro is reliable by improving the cavitation SNR beyond the 1-d

  1. Synergetic aspects of gas-discharge: lateral patterns in dc systems with a high ohmic barrier

    NASA Astrophysics Data System (ADS)

    Purwins, H.-G.; Stollenwerk, L.

    2014-12-01

    The understanding of self-organized patterns in spatially extended nonlinear dissipative systems is one of the most challenging subjects in modern natural sciences. Such patterns are also referred to as dissipative structures. We review this phenomenon in planar low temperature dc gas-discharge devices with a high ohmic barrier. It is demonstrated that for these systems a deep qualitative understanding of dissipative structures can be obtained from the point of view of synergetics. At the same time, a major contribution can be made to the general understanding of dissipative structures. The discharge spaces of the experimentally investigated systems, to good approximation, have translational and rotational symmetry by contraction. Nevertheless, a given system may exhibit stable current density distributions and related patterns that break these symmetries. Among the experimentally observed fundamental patterns one finds homogeneous isotropic states, fronts, periodic patterns, labyrinth structures, rotating spirals, target patterns and localized filaments. In addition, structures are observed that have the former as elementary building blocks. Finally, defect structures as well as irregular patterns are common phenomena. Such structures have been detected in numerous other driven nonlinear dissipative systems, as there are ac gas-discharge devices, semiconductors, chemical solutions, electrical networks and biological systems. Therefore, from the experimental observations it is concluded that the patterns in planar low temperature dc gas-discharge devices exhibit universal behavior. From the theoretical point of view, dissipative structures of the aforementioned kind are also referred to as attractors. The possible sets of attractors are an important characteristic of the system. The number and/or qualitative nature of attractors may change when changing parameters. The related bifurcation behavior is a central issue of the synergetic approach chosen in the present

  2. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    PubMed

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period. PMID:26880128

  3. The density-driven circulation of the coastal hypersaline system of the Great Barrier Reef, Australia.

    PubMed

    Salamena, Gerry G; Martins, Flávio; Ridd, Peter V

    2016-04-15

    The coastal hypersaline system of the Great Barrier Reef (GBR) in the dry season, was investigated for the first time using a 3D baroclinic model. In the shallow coastal embayments, salinity increases to c.a. 1‰ above typical offshore salinity (~35.4‰). This salinity increase is due to high evaporation rates and negligible freshwater input. The hypersalinity drifts longshore north-westward due to south-easterly trade winds and may eventually pass capes or headlands, e.g. Cape Cleveland, where the water is considerably deeper (c.a. 15m). Here, a pronounced thermohaline circulation is predicted to occur which flushes the hypersalinity offshore at velocities of up to 0.08m/s. Flushing time of the coastal embayments is around 2-3weeks. During the dry season early summer, the thermohaline circulation reduces and therefore, flushing times are predicted to be slight longer due to the reduced onshore-offshore density gradient compared to that in the dry season winter period.

  4. Mini-med school for Aboriginal youth: experiential science outreach to tackle systemic barriers

    PubMed Central

    Henderson, Rita I.; Williams, Keri; Crowshoe, Lynden (Lindsay)

    2015-01-01

    Introduction Addressing systemic barriers experienced by low-income and minority students to accessing medical school, the University of Calgary's Cumming School of Medicine has spearheaded a year-round, mini-med school outreach initiative for Aboriginal students. Method Junior and senior high school youth generally attend the half-day program in classes or camps of 15–25, breaking into small groups for multisession activities. Undergraduate medical education students mentor the youth in stations offering experiential lessons in physical examination, reading x-rays, and anatomy. All resources from the medical school are offered in-kind, including a pizza lunch at midday, whereas community partners organize transportation for the attendees. Results Opening the medical school and its resources to the community offers great benefits to resource-constrained schools often limited in terms of science education resources. The model is also an effort to address challenges among the medical professions around attracting and retaining students from underserved populations. Conclusion The prospect of increasing admission rates and successful completion of medical education among students from marginalized communities poses a real, though difficult-to-measure, possibility of increasing the workforce most likely to return to and work in such challenging contexts. A mini-medical school for Aboriginal youth highlights mutual, long-term benefit for diverse partners, encouraging medical educators and community-based science educators to explore the possibilities for deepening partnerships in their own regions. PMID:26701840

  5. International Collaborations on Engineered Barrier Systems: Brief Overview of SKB-EBS Activities.

    SciTech Connect

    Jove-Colon, Carlos F.

    2015-10-01

    Research collaborations with international partners on the behavior and performance of engineered barrier systems (EBS) are an important aspect of the DOE-NE Used Fuel Disposition Campaign strategy in the evaluation of disposal design concepts. These international partnerships are a cost-effective way of engaging in key R&D activities with common goals resulting in effective scientific knowledge exchanges thus enhancing existing and future research programs in the USA. This report provides a brief description of the activities covered by the Swedish Nuclear Fuel and Waste Management Company (SKB) EBS Task Force (TF) (referred hereafter as SKB EBS TF) and potential future directions for engagement of the DOE-NE UFDC program in relevant R&D activities. Emphasis is given to SKB EBS TF activities that are still ongoing and aligned to the UFDC R&D program. This include utilization of data collected in the bentonite rock interaction experiment (BRIE) and data sets from benchmark experiments produced by the chemistry or “C” part of the SKB EBS TF. Potential applications of information generated by this program include comparisons/tests between model and data (e.g., reactive diffusion), development and implementation of coupled-process models (e.g., HM), and code/model benchmarking.

  6. Role of the blood-brain barrier in the nutrition of the central nervous system.

    PubMed

    Campos-Bedolla, Patricia; Walter, Fruzsina R; Veszelka, Szilvia; Deli, Mária A

    2014-11-01

    The blood-brain barrier (BBB) is a dynamic and complex interface between the blood and the central nervous system regulating brain homeostasis. Major functions of the BBB include the transport of nutrients and protection of the brain from toxic compounds. This review summarizes the most important transport pathways contributing to the nutrition of the brain. Carrier-mediated transport selectively delivers small molecules like sugars, amino acids, vitamins, and trace elements. Large biomolecules, lipoproteins, peptide and protein hormones cross the BBB by receptor-mediated transport. Active efflux transporters participate in the brain efflux of endogenous metabolites as well as toxins, xenobiotics and drugs. Dysfunction in the transport of nutrients at the BBB is described in several neurological disorders and diseases. The BBB penetration of neuroprotective nutrients, especially plant polyphenols and alkaloids, their potential protective effect on brain endothelium and the interaction of nutraceuticals with active efflux transporters at the BBB are discussed. In vitro BBB models to examine nutrient transport are also presented. PMID:25481827

  7. Development of strain tolerant thermal barrier coating systems, tasks 1 - 3

    NASA Technical Reports Server (NTRS)

    Anderson, N. P.; Sheffler, K. D.

    1983-01-01

    Insulating ceramic thermal barrier coatings can reduce gas turbine airfoil metal temperatures as much as 170 C (about 300 F), providing fuel efficiency improvements greater than one percent and durability improvements of 2 to 3X. The objective was to increase the spalling resistance of zirconia based ceramic turbine coatings. To accomplish this, two baseline and 30 candidate duplex (layered MCrAlY/zirconia based ceramic) coatings were iteratively evaluated microstructurally and in four series of laboratory burner rig tests. This led to the selection of two candidate optimized 0.25 mm (0.010 inch) thick plasma sprayed partially stabilized zirconia ceramics containing six weight percent yttria and applied with two different sets of process parameters over a 0.13 mm (0.005 inch) thick low pressure chamber sprayed MCrAlY bond coat. Both of these coatings demonstrated at least 3X laboratory cyclic spalling life improvement over the baseline systems, as well as cyclic oxidation life equivalent to 15,000 commercial engine flight hours.

  8. Role of the blood-brain barrier in the nutrition of the central nervous system.

    PubMed

    Campos-Bedolla, Patricia; Walter, Fruzsina R; Veszelka, Szilvia; Deli, Mária A

    2014-11-01

    The blood-brain barrier (BBB) is a dynamic and complex interface between the blood and the central nervous system regulating brain homeostasis. Major functions of the BBB include the transport of nutrients and protection of the brain from toxic compounds. This review summarizes the most important transport pathways contributing to the nutrition of the brain. Carrier-mediated transport selectively delivers small molecules like sugars, amino acids, vitamins, and trace elements. Large biomolecules, lipoproteins, peptide and protein hormones cross the BBB by receptor-mediated transport. Active efflux transporters participate in the brain efflux of endogenous metabolites as well as toxins, xenobiotics and drugs. Dysfunction in the transport of nutrients at the BBB is described in several neurological disorders and diseases. The BBB penetration of neuroprotective nutrients, especially plant polyphenols and alkaloids, their potential protective effect on brain endothelium and the interaction of nutraceuticals with active efflux transporters at the BBB are discussed. In vitro BBB models to examine nutrient transport are also presented.

  9. Simulation of residual stresses and their effects on thermal barrier coating systems using finite element method

    NASA Astrophysics Data System (ADS)

    Zhu, JianGuo; Chen, Wei; Xie, HuiMin

    2015-03-01

    Thermal barrier coating (TBC) systems are widely used in industrial gas-turbine engines. However, premature failures have impaired the use of TBCs and cut down their lifetime, which requires a better understanding of their failure mechanisms. In the present study, experimental studies of isothermal cycling are firstly carried out with the observation and estimation of microstructures. According to the experimental results, a finite element model is established for the analysis of stress perpendicular to the TBC/BC interface. Detailed residual stress distributions in TBC are obtained to reflect the influence of mechanical properties, oxidation, and interfacial roughness. The calculated results show that the maximum tensile stress concentration appears at the peak of TBC and continues to increase with thermal cycles. Because of the microstructural characteristics of plasma-sprayed TBCs, cracks initialize in tensile stress concentration (TSC) regions at the peaks of TBC and propagate along the TBC/BC interface resulting in the spallation of TBC. Also, the inclusion of creep is crucial to failure prediction and is more important than the inclusion of sintering in the simulation.

  10. Development of Intermixed Zones of Alumina/Zirconia in Thermal Barrier Coating Systems

    NASA Astrophysics Data System (ADS)

    Stiger, M. J.; Yanar, N. M.; Jackson, R. W.; Laney, S. J.; Pettit, F. S.; Meier, G. H.; Gandhi, A. S.; Levi, C. G.

    2007-04-01

    The mechanisms whereby intermixed zones of alumina and zirconia are formed at the interface between the metallic bond coat and the ceramic top coat (yttria-stabilized zirconia) in thermal barrier coating systems have been investigated. The results lead to the following mechanism for the formation of the zones. The predominant mechanism for intermixed zone formation involves formation of a metastable alumina polymorph ( θ or γ) during TBC deposition, with a significant amount of zirconia dissolved in it. The outward growth also begins to incorporate zirconia particles, which initiates the formation of the intermixed zone. Upon thermal exposure, the metastable TGO continues to grow outward, extending the intermixed zone, and eventually transforms to the equilibrium α-Al2O3. The transformation to α-Al2O3 results in an increase in the volume fraction of zirconia in the intermixed zone as it is rejected from solution. Once the α-Al2O3 appears, subsequent TGO growth produces a columnar zone of the TGO without a second phase. When α-alumina was preformed on the bond coat, prior to TBC deposition, no intermixed zone was formed for Pt-modified aluminide bond coats.

  11. Health system and societal barriers for gestational diabetes mellitus (GDM) services - lessons from World Diabetes Foundation supported GDM projects

    PubMed Central

    2012-01-01

    Background Maternal mortality and morbidity remains high in many low- and middle-income countries (LMIC). Gestational Diabetes Mellitus (GDM) represents an underestimated and unrecognised impediment to optimal maternal health in LMIC; left untreated – it also has severe consequences for the offspring. A better understanding of the barriers hindering detection and treatment of GDM is needed. Based on experiences from World Diabetes Foundation (WDF) supported GDM projects this paper seeks to investigate societal and health system barriers to such efforts. Methods Questionnaires were filled out by 10 WDF supported GDM project partners implementing projects in eight different LMIC. In addition, interviews were conducted with the project partners. The interviews were analysed using content analysis. Results Barriers to improving maternal health related to GDM nominated by project implementers included lack of trained health care providers - especially female doctors; high staff turnover; lack of standard protocols, consumables and equipment; financing of health services and treatment; lack of or poor referral systems, feedback mechanisms and follow-up systems; distance to health facility; perceptions of female body size and weight gain/loss in relation to pregnancy; practices related to pregnant women’s diet; societal negligence of women’s health; lack of decision-making power among women regarding their own health; stigmatisation; role of women in society and expectations that the pregnant woman move to her maternal home for delivery. Conclusions A number of barriers within the health system and society exist. Programmes need to consider and address these barriers in order to improve GDM care and thereby maternal health in LMIC. PMID:23217159

  12. Tsunami hazard assessment in the southern Colombian Pacific Basin and a proposal to regenerate a previous barrier island as protection

    NASA Astrophysics Data System (ADS)

    Otero, L. J.; Restrepo, J. C.; Gonzalez, M.

    2013-04-01

    In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. To reduce the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco.

  13. Tsunami hazard assessment in the southern Colombian Pacific basin and a proposal to regenerate a previous barrier island as protection

    NASA Astrophysics Data System (ADS)

    Otero, L. J.; Restrepo, J. C.; Gonzalez, M.

    2014-05-01

    In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. By reducing the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco.

  14. Environmental life cycle assessment of permeable reactive barriers: effects of construction methods, reactive materials and groundwater constituents.

    PubMed

    Mak, Mark S H; Lo, Irene M C

    2011-12-01

    The effects of the construction methods, materials of reactive media and groundwater constituents on the environmental impacts of a permeable reactive barrier (PRB) were evaluated using life cycle assessment (LCA). The PRB is assumed to be installed at a simulated site contaminated by either Cr(VI) alone or Cr(VI) and As(V). Results show that the trench-based construction method can reduce the environmental impacts of the remediation remarkably compared to the caisson-based method due to less construction material consumption by the funnel. Compared to using the zerovalent iron (Fe(0)) and quartz sand mixture, the use of the Fe(0) and iron oxide-coated sand (IOCS) mixture can reduce the environmental impacts. In the presence of natural organic matter (NOM) in groundwater, the environmental impacts generated by the reactive media were significantly increased because of the higher usage of Fe(0). The environmental impacts are lower by using the Fe(0) and IOCS mixture in the groundwater with NOM, compared with using the Fe(0) and quartz sand mixture. Since IOCS can enhance the removal efficiency of Cr(VI) and As(V), the usage of the Fe(0) can be reduced, which in turn reduces the impacts induced by the reactive media.

  15. Development and Effectiveness of a Dairy Foods Curriculum Packet and Inservice and the Assessment of Barriers to Dairy Foods Education

    ERIC Educational Resources Information Center

    Kahnke, Sheri L.; Baer, Robert J.; Portillo, Matthew T.

    2006-01-01

    A Dairy Foods Curriculum Packet and inservice training were provided to South Dakota high school agricultural education instructors. Instructors rated barriers to implementation of teaching dairy foods as "small to medium barriers." After curriculum distribution and inservice training, more than half of instructors indicated an increase in class…

  16. Afghanistan irrigation system assessment using remote sensing

    NASA Astrophysics Data System (ADS)

    Haack, Barry

    1997-01-01

    The Helmand-Arghandab Valley irrigation system in southern Afghanistan is one of the country's most important capital resources. Prior to the civil and military conflict that has engulfed Afghanistan for more than 15 years, agricultural lands irrigated by the system produced a large proportion of the country's food grains and cotton. This study successfully employed Landsat satellite imagery, Geographic Information Systems (GIS), Global Positioning Systems (GPS), and field surveys to assess changes that have occurred in this system since 1973 as a consequence of the war. This information is a critical step in irrigation rehabilitation for restoration of Afghanistan's agricultural productivity.

  17. Development of a Psychological Assessment System

    PubMed Central

    Lushene, Robert E.

    1981-01-01

    The development and validation of a psychological assessment system is described. The system currently has the capability to administer, score, and in many cases interpret, 62 different psychological tests. In addition, the system collects patient information by automated interviews in 18 areas of relevance. The system also has the capability of assisting the development of psychiatric diagnoses utilizing the new DSM III diagnostic criteria. The present system, programmed in ANS MUMPS, has been used to administer over 8,000 psychological tests and has received excellent acceptance in the institutions where it has been installed.

  18. Quantitative performance assessments for neuromagnetic imaging systems.

    PubMed

    Koga, Ryo; Hiyama, Ei; Matsumoto, Takuya; Sekihara, Kensuke

    2013-01-01

    We have developed a Monte-Carlo simulation method to assess the performance of neuromagnetic imaging systems using two kinds of performance metrics: A-prime metric and spatial resolution. We compute these performance metrics for virtual sensor systems having 80, 160, 320, and 640 sensors, and discuss how the system performance is improved, depending on the number of sensors. We also compute these metrics for existing whole-head MEG systems, MEGvision™ (Yokogawa Electric Corporation, Tokyo, Japan) that uses axial-gradiometer sensors, and TRIUX™ (Elekta Corporate, Stockholm, Sweden) that uses planar-gradiometer and magnetometer sensors. We discuss performance comparisons between these significantly different systems.

  19. Quantitative performance assessments for neuromagnetic imaging systems.

    PubMed

    Koga, Ryo; Hiyama, Ei; Matsumoto, Takuya; Sekihara, Kensuke

    2013-01-01

    We have developed a Monte-Carlo simulation method to assess the performance of neuromagnetic imaging systems using two kinds of performance metrics: A-prime metric and spatial resolution. We compute these performance metrics for virtual sensor systems having 80, 160, 320, and 640 sensors, and discuss how the system performance is improved, depending on the number of sensors. We also compute these metrics for existing whole-head MEG systems, MEGvision™ (Yokogawa Electric Corporation, Tokyo, Japan) that uses axial-gradiometer sensors, and TRIUX™ (Elekta Corporate, Stockholm, Sweden) that uses planar-gradiometer and magnetometer sensors. We discuss performance comparisons between these significantly different systems. PMID:24110711

  20. Political, policy and social barriers to health system interoperability: emerging opportunities of Web 2.0 and 3.0.

    PubMed

    Juzwishin, Donald W M

    2009-01-01

    Achieving effective health informatics interoperability in a fragmented and uncoordinated health system is by definition not possible. Interoperability requires the simultaneous integration of health care processes and information across different types and levels of care (systems thinking). The fundamental argument of this paper is that information system interoperability will remain an unfulfilled hope until health reforms effectively address the governance (accountability), structural and process barriers to interoperability of health care delivery. The ascendency of Web 2.0 and 3.0, although still unproven, signals the opportunity to accelerate patients' access to health information and their health record. Policy suggestions for simultaneously advancing health system delivery and information system interoperability are posited.

  1. Evaluation of knit glove fabrics as barriers to dermal absorption of organophosphorus insecticides using an in vitro test system.

    PubMed

    Keeble, V B; Correll, L; Ehrich, M

    1993-08-27

    Cotton and synthetic knit glove fabrics in combination with an in vitro skin model were used to examine the capability of fabric to decrease the dermal absorption of the organophosphorus insecticides azinphos-methyl, paraoxon, and malathion. Capability for inhibition of acetylcholinesterase was determined in samples of media taken from under the skin barrier after the skin model, with or without fabric protection, had been exposed to the test compounds for 4 h. Acetylcholinesterase inhibitions caused by the direct addition of organophosphorus insecticide to the media were also included in the comparison. Results indicated that the skin model system alone had some capability to serve as a barrier to the transfer of organophosphates. Fabric covering used on the test model increased the barrier between insecticide application and resultant acetylcholinesterase inhibition. The all-cotton, 7-cut knit was especially effective in preventing the absorption of azinphos-methyl, as this organophosphorus insecticide had no capability to cause acetylcholinesterase inhibition when this fabric was used to protect the skin model. Knit glove materials of 100% cotton were demonstrated to be effective in preventing the absorption of paraoxon and malathion. These studies indicate that an in vitro model system can be used in combination with fabrics to study the relationship between clothing and skin as barriers to the absorption of organophosphorus insecticides.

  2. Copper transport mediated by nanocarrier systems in a blood-brain barrier in vitro model.

    PubMed

    Fehse, Susanne; Nowag, Sabrina; Quadir, Mohiuddin; Kim, Kwang Sik; Haag, Rainer; Multhaup, Gerd

    2014-05-12

    Copper (Cu) is a cofactor of various metalloenzymes and has a role in neurodegenerative diseases with disturbed Cu homeostasis, for example, in Alzheimer's disease (AD) and Menkes disease. To address Cu imbalances, we synthesized two different dendritic nanoparticles (NP) for the transport of Cu(II) ions across the blood-brain barrier (BBB). The synthesized NPs show low toxicity and high water solubility and can stabilize high amounts of Cu(II). The Cu(II)-laden NPs crossed cellular membranes and increased the cellular Cu level. A human brain microvascular endothelial cell (HBMEC) model was established to investigate the permeability of the NPs through the BBB. By comparing the permeability × surface area product (PSe) of reference substances with those of NPs, we observed that NPs crossed the BBB model two times more effectively than (14)C-sucrose and sodium fluorescein (NaFl) and up to 60× better than Evans Blue labeled albumin (EBA). Our results clearly indicate that NPs cross the BBB model effectively. Furthermore, Cu was shielded by the NPs, which decreased the Cu toxicity. The novel design of the core-shell NP enabled the complexation of Cu(II) in the outer shell and therefore facilitated the pH-dependent release of Cu in contrast to core-multishell NPs, where the Cu(II) ions are encapsulated in the core. This allows a release of Cu into the cytoplasm. In addition, by using a cellular detection system based on a metal response element with green fluorescent protein (MRE-GFP), we demonstrated that Cu could also be released intracellularly from NPs and is accessible for biological processes. Our results indicate that NPs are potential candidates to rebalance metal-ion homeostasis in disease conditions affecting brain and neuronal systems.

  3. Mobile Munitions Assessment System Field Capabilities

    SciTech Connect

    A. M. Snyder; D. A. Verrill; K. D. Watts

    1999-05-27

    The US has developed, stored, tested, and conducted disposal operations on various forms of chemical munitions for several decades. The remnants of these activities have resulted in the presence of suspect CWM at more than 200 sites in the US, the District of Columbia, and the US Virgin Islands. An advanced Mobile Munitions Assessment System (Phase II MMAS) has been designed, fabricated, assembled, and tested by the Idaho National Engineering and Environmental Laboratory under contract to the US Army's Project Manager for Non-Stockpile Chemical Materiel for use in the assessment and characterization of ''non-stockpile'' chemical warfare materiel (CWM). The Phase II MMAS meets the immediate need to augment response equipment currently used by the US Army with a system that includes state-of-the-art assessment equipment and advanced sensors. The Phase II MMAS will be used for response to known storage and remediation sites. This system is designed to identify the munition type; evaluate the condition of the CWM; evaluate the environmental conditions in the vicinity of the CWM; determine if fuzes, bursters, or safety and arming devices are in place; identify the chemical fill; provide other data (e.g., meteorological data) necessary for assessing the risk associated with handling, transporting, and disposing of CWM; and record the data on a dedicated computer system. The Phase II MMAS is capable of over-the-road travel and air transport to any site for conducting rigorous assessments of suspect CWM. The Phase II MMAS utilizes a specially-designed commercial motor home to provide a means to transport an interactive network of non-intrusive characterization and assessment equipment. The assessment equipment includes radiography systems, a gamma densitometer system, a Portable Isotopic Neutron Spectroscopy (PINS) system, a Secondary Ion Mass Spectroscopy (SIMS) system, air monitoring equipment (i.e., M-90s and a field ion spectroscopy system), and a phase determination

  4. A Load-based Depth-sensing Indentation Technique for NDE and Life Assessment of Thermal Barrier Coatings

    SciTech Connect

    B. S.-J. Kang; C. Feng; J. M. Tannenbaum; M.A. Alvin

    2009-06-12

    In this paper, we present a load-based micro-indentation technique for evaluating material mechanical properties as well as degradation evaluation and debonding/spallation detection of thermal barrier coating (TBC) materials. Instead of using contact area as a necessary parameter, the new technique is based on the indentation load. Coupled with a multiple-partial unloading procedure during the indentation process, this technique results in a load-depth sensing indentation system capable of determining Young’s modulus of metals, superalloys, and single crystal matrices, and stiffness of coated material systems with flat, tubular, or curved architectures. This micro-indentation technique can be viewed as a viable non-destructive evaluation (NDE) technique for determining as-manufactured and process-exposed metal, superalloy, single crystal, and TBC-coated material properties. This technique also shows promise for the development of a portable instrument for on-line, in-situ NDE and mechanical properties measurement of structural components.

  5. Numerical investigations of failure in EB-PVD thermal barrier coating systems

    NASA Astrophysics Data System (ADS)

    Glynn, Michael L.

    Thermal barrier coating (TBC) systems are used in high temperature applications in turbine engines. TBCs are applied on superalloy substrates and are multilayered coatings comprised of a metallic bond coat, a thermally grown oxide (TGO) and a ceramic top coat. They provide thermal protection for the superalloy substrate and are considered to hold the greatest potential for increased operating temperatures. Failure of the TBC system most commonly occurs as a result of large scale buckling and spallation. The buckling is a consequence of many small-scale delaminations that arise in the top coat above local imperfections in the TGO, and durability of the TBC system is governed by a sequence of crack nucleation, propagation and coalescence. The numerical investigations that are employed in this dissertation are used to determine the stress development near the imperfections and are based on microstructural observations and measured material properties of TBC test buttons supplied by GE Aircraft Engines. The test buttons were subject to thermal cycling at GE and cycled to different percentages of TBC life. Numerical simulations of two different types of TBC tests are used to show that the top coat out-of-plane stress increases with a decrease of the substrate radius of curvature and a decrease in the heating rate. An inherent scaling parameter in the TBC system is identified and used to demonstrate that the stress developed in the top coat is governed by the evolution of an imperfection in the TGO. The effect of a martensitic phase transformation in the bond coat, related to a change in bond coat chemistry, is shown to significantly increase the top coat out-of-plane tensile stress. Finally, a subsurface crack is simulated in the top coat and used to determine the influence of the bond coat on failure of the TBC system. While the bond coat inelastic properties are the most important factors in determining the extent of the crack opening displacement, the bond coat

  6. Decontamination systems information and research program -- Literature review in support of development of standard test protocols and barrier design models for in situ formed barriers project

    SciTech Connect

    1994-12-01

    The US Department of Energy is responsible for approximately 3,000 sites in which contaminants such as carbon tetrachloride, trichlorethylene, perchlorethylene, non-volatile and soluble organic and insoluble organics (PCBs and pesticides) are encountered. In specific areas of these sites radioactive contaminants are stored in underground storage tanks which were originally designed and constructed with a 30-year projected life. Many of these tanks are now 10 years beyond the design life and failures have occurred allowing the basic liquids (ph of 8 to 9) to leak into the unconsolidated soils below. Nearly one half of the storage tanks located at the Hanford Washington Reservation are suspected of leaking and contaminating the soils beneath them. The Hanford site is located in a semi-arid climate region with rainfall of less than 6 inches annually, and studies have indicated that very little of this water finds its way to the groundwater to move the water down gradient toward the Columbia River. This provides the government with time to develop a barrier system to prevent further contamination of the groundwater, and to develop and test remediation systems to stabilize or remove the contaminant materials. In parallel to remediation efforts, confinement and containment technologies are needed to retard or prevent the advancement of contamination plumes through the environment until the implementation of remediation technology efforts are completed. This project examines the various confinement and containment technologies and protocols for testing the materials in relation to their function in-situ.

  7. Microstructure and Property of Self-format Graded Diffusion Barrier in Cu(Zr)/ZrN Film System

    NASA Astrophysics Data System (ADS)

    Song, Zhongxiao; Li, Yanhuai; He, Guohua; Yao, Ling; Wang, Jiaan; Guo, Shengwu; Xu, Kewei

    In this paper, Cu(Zr)/ZrN alloy film system on Si(100) substrates were sputtered using magnetron co-sputtering technology. The Cu films sputtered with magnetron sputtering were used as control experiments. Microstructure and properties of the films system were investigated by four-Point Probe (FPP) sheet-resistance measurement, XRD, HRTEM respectively. After annealed at 500°C, Cu(Zr)/ZrN/Si system films self-formed a layer about 5 nm between the alloy layer and ZrN interface, which was an self-format amorphous Zr-rich barrier layer. Therefore, a gradient Zr/ZrN double-diffusion barrier layer can effectively block the interaction between Cu and Si substrate.

  8. Mechanical system reliability and risk assessment

    NASA Astrophysics Data System (ADS)

    Cruse, T. A.; Mahadevan, S.; Huang, Q.; Mehta, S.

    1994-11-01

    A new methodology is reported for the prediction of the reliability of mechanical structures subject to multiple failure modes, including noncritical damage. The reduction of system reliability due to accumulated damage is quantitatively estimated by updating the critical system failure states at each level of damage. Correlated design variables are automatically accounted for in the system reliability calculations. Second-order reliability bounds are reported which are unbiased to the ordering of the events. A system risk assessment methodology is also reported that accounts for the cost of multiple types of failure modes and includes the effect of inspection success on reducing the consequences of system failure. Application of the new technology is illustrated for a simplified system model of an aeropropulsion rotor system. However, the methodology is general and is applicable to any engineering system.

  9. Diffusion barriers

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.

    1983-01-01

    The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

  10. Quantification of inlet-related hazards in barrier island systems. An example from the Ria Formosa (Portugal)

    NASA Astrophysics Data System (ADS)

    Vila-Concejo, A.; Matias, A.; Pacheco, A.; Ferreira, Ó.; Dias, J. A.

    2006-06-01

    Determination of inlet hazard areas (IHAs) is important for the management of barrier island systems such as the Ria Formosa. An IHA is an area of natural importance that can be easily destroyed by inlet-related processes and covers the land adjacent to inlets [CAMA, 2004. Handbook for Development in Coastal North Carolina. Division of Coastal Management from the North Carolina State Department of Environmental and Natural Resources. http://www.nccoastalmanagement.net/Handbook/contents.htm, (accessed 07.04)]. One parameter is defined in order to quantify the extension of the inlet-associated hazards within a barrier island system. This parameter, the minimum inlet hazard area (IHA min), represents the extent of the minimum area that should be taken into account when analysing inlet-associated hazards and is determined using the following criteria: (a) inlet maximum width; (b) inlet migration path and (c) existence of frequently overwashed areas that can be related to present or historic inlets. The calculation of the IHA min was applied to the Ria Formosa barrier island system (southern Portugal) for a time scale of decades. For the Ria Formosa the IHA min represents approximately 45% of the total length of the system. Most of the occupied areas within the barrier chain are located inside the IHA min. Changes in the configuration and number of inlets of the system would modify the total IHA min calculated for the entire area. However, assuming that the typical migration patterns identified for the system do not change, the herein proposed methodology can still be applicable to calculate the new associated IHA min. This study showed that other studies should be considered in future work including: (i) quantifying buffer distances on both sides of the IHA min and (ii) analyses of the inland extent of the hazardous areas. The IHA min is an easy-to-use parameter that could be quantified for other inlets located in other parts of the world.

  11. NASA Human System Risk Assessment Process

    NASA Technical Reports Server (NTRS)

    Francisco, D.; Romero, E.

    2016-01-01

    NASA utilizes an evidence based system to perform risk assessments for the human system for spaceflight missions. The center of this process is the multi-disciplinary Human System Risk Board (HSRB). The HSRB is chartered from the Chief Health and Medical Officer (OCHMO) at NASA Headquarters. The HSRB reviews all human system risks via an established comprehensive risk and configuration management plan based on a project management approach. The HSRB facilitates the integration of human research (terrestrial and spaceflight), medical operations, occupational surveillance, systems engineering and many other disciplines in a comprehensive review of human system risks. The HSRB considers all factors that influence human risk. These factors include pre-mission considerations such as screening criteria, training, age, sex, and physiological condition. In mission factors such as available countermeasures, mission duration and location and post mission factors such as time to return to baseline (reconditioning), post mission health screening, and available treatments. All of the factors influence the total risk assessment for each human risk. The HSRB performed a comprehensive review of all potential inflight medical conditions and events and over the course of several reviews consolidated the number of human system risks to 30, where the greatest emphasis is placed for investing program dollars for risk mitigation. The HSRB considers all available evidence from human research and, medical operations and occupational surveillance in assessing the risks for appropriate mitigation and future work. All applicable DRMs (low earth orbit for 6 and 12 months, deep space for 30 days and 1 year, a lunar mission for 1 year, and a planetary mission for 3 years) are considered as human system risks are modified by the hazards associated with space flight such as microgravity, exposure to radiation, distance from the earth, isolation and a closed environment. Each risk has a summary

  12. Barrier Island Hazard Mapping.

    ERIC Educational Resources Information Center

    Pilkey, Orrin H.; Neal, William J.

    1980-01-01

    Describes efforts to evaluate and map the susceptibility of barrier islands to damage from storms, erosion, rising sea levels and other natural phenomena. Presented are criteria for assessing the safety and hazard potential of island developments. (WB)

  13. Engine system assessment study using Martian propellants

    NASA Technical Reports Server (NTRS)

    Pelaccio, Dennis; Jacobs, Mark; Scheil, Christine; Collins, John

    1992-01-01

    A top-level feasibility study was conducted that identified and characterized promising chemical propulsion system designs which use two or more of the following propellant combinations: LOX/H2, LOX/CH4, and LOX/CO. The engine systems examined emphasized the usage of common subsystem/component hardware where possible. In support of this study, numerous mission scenarios were characterized that used various combinations of Earth, lunar, and Mars propellants to establish engine system requirements to assess the promising engine system design concept examined, and to determine overall exploration leverage of such systems compared to state-of-the-art cryogenic (LOX/H2) propulsion systems. Initially in the study, critical propulsion system technologies were assessed. Candidate expander and gas generator cycle LOX/H2/CO, LOX/H2/CH4, and LOX/CO/CH4 engine system designs were parametrically evaluated. From this evaluation baseline, tripropellant Mars Transfer Vehicle (MTV) LOX cooled and bipropellant Lunar Excursion Vehicle (LEV) and Mars Excursion Vehicle (MEV) engine systems were identified. Representative tankage designs for a MTV were also investigated. Re-evaluation of the missions using the baseline engine design showed that in general the slightly lower performance, smaller, lower weight gas generator cycle-based engines required less overall mission Mars and in situ propellant production (ISPP) infrastructure support compared to the larger, heavier, higher performing expander cycle engine systems.

  14. Engine system assessment study using Martian propellants

    NASA Astrophysics Data System (ADS)

    Pelaccio, Dennis; Jacobs, Mark; Scheil, Christine; Collins, John

    1992-06-01

    A top-level feasibility study was conducted that identified and characterized promising chemical propulsion system designs which use two or more of the following propellant combinations: LOX/H2, LOX/CH4, and LOX/CO. The engine systems examined emphasized the usage of common subsystem/component hardware where possible. In support of this study, numerous mission scenarios were characterized that used various combinations of Earth, lunar, and Mars propellants to establish engine system requirements to assess the promising engine system design concept examined, and to determine overall exploration leverage of such systems compared to state-of-the-art cryogenic (LOX/H2) propulsion systems. Initially in the study, critical propulsion system technologies were assessed. Candidate expander and gas generator cycle LOX/H2/CO, LOX/H2/CH4, and LOX/CO/CH4 engine system designs were parametrically evaluated. From this evaluation baseline, tripropellant Mars Transfer Vehicle (MTV) LOX cooled and bipropellant Lunar Excursion Vehicle (LEV) and Mars Excursion Vehicle (MEV) engine systems were identified. Representative tankage designs for a MTV were also investigated. Re-evaluation of the missions using the baseline engine design showed that in general the slightly lower performance, smaller, lower weight gas generator cycle-based engines required less overall mission Mars and in situ propellant production (ISPP) infrastructure support compared to the larger, heavier, higher performing expander cycle engine systems.

  15. Aging assessment for active fire protection systems

    SciTech Connect

    Ross, S.B.; Nowlen, S.P.; Tanaka, T.

    1995-06-01

    This study assessed the impact of aging on the performance and reliability of active fire protection systems including both fixed fire suppression and fixed fire detection systems. The experience base shows that most nuclear power plants have an aggressive maintenance and testing program and are finding degraded fire protection system components before a failure occurs. Also, from the data reviewed it is clear that the risk impact of fire protection system aging is low. However, it is assumed that a more aggressive maintenance and testing program involving preventive diagnostics may reduce the risk impact even further.

  16. Design Vulnerability Assessments for Safeguards Sealing Systems

    SciTech Connect

    Brockman, Linda; Johnston, Roger; Kravtchenko, Victor; Undem, Halvor A.; Wishard, Bernard

    2010-08-11

    The International Atomic Energy Agency (the "Agency") engages in a rigorous equipment authorization process prior to deploying Safeguards instrumentation, including Safeguards sealing systems, for world-wide use. A positive result from a vulnerability assessment is one of the many requirements that must be met prior to instrumentation deployment. Given the long time period in the Safeguards instrumentation development cycle, the substantial Member State investments made, and the significant Agency staff time required, a negative result for the vulnerability assessment can result in the loss of time, considerable additional expense, or even the failure to deploy an instrument or sealing system at all. First suggested in 1998 by the General Physics Institute in Moscow, an approach that incorporates a design vulnerability assessment minimizes the risk of deployment failure by teaming a public sector vulnerability assessment team with the instrument or sealing system design team in order to identify, at the earliest possible design stage, inherent vulnerabilities. Involving the vulnerability assessors early and often in the design and development process avoids many of the problems inherent in evaluating security vulnerabilities only after the design is finalized. The disadvantages include increased costs and time to deployment. An improved pressure-sensitive adhesive label seal, called the "VOID-3 seal" was developed for the Agency using this design vulnerability assessment process.

  17. Thermal High- and Low-Cycle Fatigue Behavior of Thick Thermal Barrier Coating Systems

    NASA Technical Reports Server (NTRS)

    Miller, Robert A.

    1998-01-01

    Ceramic thermal barrier coatings have received increasing attention for advanced gas turbine and diesel engine applications because of their ability to provide thermal insulation to engine components. However, the durability of these coatings under the severe thermal cycling conditions encountered in a diesel engine (ref. 1) still remains a major issue. In this research at the NASA Lewis Research Center, a high-power laser was used to investigate the thermal fatigue behavior of a yttria-stabilized zirconia coating system under simulated diesel engine conditions. The mechanisms of fatigue crack initiation and propagation, and of coating failure under complex thermal low-cycle fatigue (LCF, representing stop/start cycles) and thermal high-cycle fatigue (HCF, representing operation at 1300 rpm) are described. Continuous wave and pulse laser modes were used to simulate pure LCF and combined LCF/HCF, respectively (ref. 2). The LCF mechanism was found to be closely related to the coating sintering and creep at high temperatures. These creep strains in the ceramic coating led to a tensile stress state during cooling, thus providing the major driving force for crack growth under LCF conditions. The combined LCF/HCF tests induced more severe coating surface cracking, microspallation, and accelerated crack growth than did the pure LCF test. HCF thermal loads also facilitated lateral crack branching and ceramic/bond coat interface delaminations. HCF is associated with the cyclic stresses originating from the high-frequency temperature fluctuation at the ceramic coating surface. The HCF thermal loads act on the crack by a wedging mechanism (ref. 1), resulting in continuous crack growth at temperature. The HCF stress intensity factor amplitude increases with the interaction depth and temperature swing, and decreases with the crack depth. HCF damage also increases with the thermal expansion coefficient and the Young's modulus of the ceramic coating (refs. 1 and 3).

  18. Pathways and Hydrography in the Mesoamerican Barrier Reef System Part 1: Circulation

    NASA Astrophysics Data System (ADS)

    Carrillo, L.; Johns, E. M.; Smith, R. H.; Lamkin, J. T.; Largier, J. L.

    2015-10-01

    Acoustic Doppler Current Profiler (ADCP) measurements and surface drifters released from two oceanographic cruises conducted during March 2006 and January/February 2007 are used to investigate the circulation off the Mesoamerican Barrier Reef System (MBRS). We show that the MBRS circulation can be divided into two distinct regimes, a northern region dominated by the strong, northward-flowing Yucatan Current, and a southern region with weaker southward coastal currents and the presence of the Honduras Gyre. The latitude of impingement of the Cayman Current onto the coastline varies with time, and creates a third region, which acts as a boundary between the northern and southern circulation regimes. This circulation pattern yields two zones in terms of dispersal, with planktonic propagules in the northern region being rapidly exported to the north, whereas plankton in the southern and impingement regions may be retained locally or regionally. The latitude of the impingement region shifts interannually and intra-annually up to 3° in latitude. Sub-mesoscale features are observed in association with topography, e.g., flow bifurcation around Cozumel Island, flow wake north of Chinchorro Bank and separation of flow from the coast just north of Bahia de la Ascencion. This third feature is evident as cyclonic recirculation in coastal waters, which we call the Ascencion-Cozumel Coastal Eddy. An understanding of the implications of these different circulation regimes on water mass distributions, population connectivity, and the fate of land-based pollutants in the MBRS is critically important to better inform science-based resource management and conservation plans for the MBRS coral reefs.

  19. Monitoring fluid evolution in an Engineered Barrier System using NEO-magnets

    NASA Astrophysics Data System (ADS)

    Rigonat, N.; Butler, I. B.

    2015-12-01

    Long-term monitoring of the evolution of the engineered barrier system (EBS) of a Geological Disposal Facility (GDF) is important for establishing the safety case for deep disposal of the UK inventory of high level radioactive waste. With a view to developing techniques for remote fluid monitoring using magnetic properties, we have examined the correlation between the corrosion properties of NEO-magnets and related changes in the magnetic properties of the alloy with fluid chemistry and crystal-chemical changes of the Na-bentonite matrix. Batch experiments comprised fragments of NEO-magnets with deionised water, saline and alkaline solution both in the presence and absence of MX-80 bentonite, and were performed in sealed vessels for durations of up to 5 months at 70°C. This study combined PXRD, thermomagnetic and hysteresis analysis to demonstrate how progressive hydrogenation of the main magnetic phase led to a maximum loss of remanence and coercitivity and increasing Curie temperature in the samples reacted with deionised water with the samples reacted in saline and alkaline solutions showing smaller changes. Semi-quantitative analysis allowed comparison of the Curie temperatures with crystal-chemical parameters. This reveals a clear positive correlation of increasing lattice parameters a and c (and cell volume) with mean hydrogens per unit formula and the Curie temperature of the product NdFeB hydrides. Precipitation of Nd and Fe hydrides/oxyhydroxides is also demonstated by the PXRD data. A crucial role is played by the transformations occurring to the smectite matrix, in particular by the cation exchange in the interlayer, which causes precipitation of highly charged K- and Ca-smectites. This study demonstrates how NEO-magnets are capable of detecting water saturation in the EBS, and that the NdFeB corrosion properties are strongly controlled by the initial fluid composition and presence / absence of the bentonite matrix.

  20. Facilitators and barriers to doing workplace mental health research: Case study of acute psychological trauma in a public transit system.

    PubMed

    Links, Paul S; Bender, Ash; Eynan, Rahel; O'Grady, John; Shah, Ravi

    2016-03-10

    The Acute Psychological Trauma (APT) Study was a collaboration between an acute care hospital, a specialized multidisciplinary program designed to meet the mental health needs of injured workers, and a large urban public transit system. The overall purpose was to evaluate a Best Practices Intervention (BPI) for employees affected by acute psychological trauma compared to a Treatment as Usual (TAU) group. The specific purpose is to discuss facilitators and barriers that were recognized in implementing and carrying out mental health research in a workplace setting. Over the course of the APT study, a joint implementation committee was responsible for day-to-day study operations and made regular observations on the facilitators and barriers that arose throughout the study. The facilitators to this study included the longstanding relationships among the partners, increased recognition for the need of mental health research in the workplace, and the existence of a community advisory committee. The significant barriers to doing this study of mental health research in the workplace included differences in organizational culture, inconsistent union support, co-interventions, and stigma. Researchers and funding agencies need to be flexible and provide additional resources in order to overcome the barriers that can exist doing workplace mental health research.

  1. Blood-brain barrier models and their relevance for a successful development of CNS drug delivery systems: a review.

    PubMed

    Bicker, Joana; Alves, Gilberto; Fortuna, Ana; Falcão, Amílcar

    2014-08-01

    During the research and development of new drugs directed at the central nervous system, there is a considerable attrition rate caused by their hampered access to the brain by the blood-brain barrier. Throughout the years, several in vitro models have been developed in an attempt to mimic critical functionalities of the blood-brain barrier and reliably predict the permeability of drug candidates. However, the current challenge lies in developing a model that retains fundamental blood-brain barrier characteristics and simultaneously remains compatible with the high throughput demands of pharmaceutical industries. This review firstly describes the roles of all elements of the neurovascular unit and their influence on drug brain penetration. In vitro models, including non-cell based and cell-based models, and in vivo models are herein presented, with a particular emphasis on their methodological aspects. Lastly, their contribution to the improvement of brain drug delivery strategies and drug transport across the blood-brain barrier is also discussed.

  2. Facilitators and barriers to doing workplace mental health research: Case study of acute psychological trauma in a public transit system.

    PubMed

    Links, Paul S; Bender, Ash; Eynan, Rahel; O'Grady, John; Shah, Ravi

    2016-03-10

    The Acute Psychological Trauma (APT) Study was a collaboration between an acute care hospital, a specialized multidisciplinary program designed to meet the mental health needs of injured workers, and a large urban public transit system. The overall purpose was to evaluate a Best Practices Intervention (BPI) for employees affected by acute psychological trauma compared to a Treatment as Usual (TAU) group. The specific purpose is to discuss facilitators and barriers that were recognized in implementing and carrying out mental health research in a workplace setting. Over the course of the APT study, a joint implementation committee was responsible for day-to-day study operations and made regular observations on the facilitators and barriers that arose throughout the study. The facilitators to this study included the longstanding relationships among the partners, increased recognition for the need of mental health research in the workplace, and the existence of a community advisory committee. The significant barriers to doing this study of mental health research in the workplace included differences in organizational culture, inconsistent union support, co-interventions, and stigma. Researchers and funding agencies need to be flexible and provide additional resources in order to overcome the barriers that can exist doing workplace mental health research. PMID:26967029

  3. Process for Selecting System Level Assessments for Human System Technologies

    NASA Technical Reports Server (NTRS)

    Watts, James; Park, John

    2006-01-01

    The integration of many life support systems necessary to construct a stable habitat is difficult. The correct identification of the appropriate technologies and corresponding interfaces is an exhaustive process. Once technologies are selected secondary issues such as mechanical and electrical interfaces must be addressed. The required analytical and testing work must be approached in a piecewise fashion to achieve timely results. A repeatable process has been developed to identify and prioritize system level assessments and testing needs. This Assessment Selection Process has been defined to assess cross cutting integration issues on topics at the system or component levels. Assessments are used to identify risks, encourage future actions to mitigate risks, or spur further studies.

  4. Laptop Computer - Based Facial Recognition System Assessment

    SciTech Connect

    R. A. Cain; G. B. Singleton

    2001-03-01

    The objective of this project was to assess the performance of the leading commercial-off-the-shelf (COTS) facial recognition software package when used as a laptop application. We performed the assessment to determine the system's usefulness for enrolling facial images in a database from remote locations and conducting real-time searches against a database of previously enrolled images. The assessment involved creating a database of 40 images and conducting 2 series of tests to determine the product's ability to recognize and match subject faces under varying conditions. This report describes the test results and includes a description of the factors affecting the results. After an extensive market survey, we selected Visionics' FaceIt{reg_sign} software package for evaluation and a review of the Facial Recognition Vendor Test 2000 (FRVT 2000). This test was co-sponsored by the US Department of Defense (DOD) Counterdrug Technology Development Program Office, the National Institute of Justice, and the Defense Advanced Research Projects Agency (DARPA). Administered in May-June 2000, the FRVT 2000 assessed the capabilities of facial recognition systems that were currently available for purchase on the US market. Our selection of this Visionics product does not indicate that it is the ''best'' facial recognition software package for all uses. It was the most appropriate package based on the specific applications and requirements for this specific application. In this assessment, the system configuration was evaluated for effectiveness in identifying individuals by searching for facial images captured from video displays against those stored in a facial image database. An additional criterion was that the system be capable of operating discretely. For this application, an operational facial recognition system would consist of one central computer hosting the master image database with multiple standalone systems configured with duplicates of the master operating in

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

    SciTech Connect

    Banovic, S.W.; Barmak, K.; Chan, H.M.

    1995-10-01

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

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

    SciTech Connect

    Banovic, S.W.; Chan, H.M.; Marder, A.R.

    1995-12-31

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

  7. Method of installing subsurface barrier

    DOEpatents

    Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.

    2007-10-09

    Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.

  8. In vitro assessment of biodurability: acellular systems.

    PubMed Central

    de Meringo, A; Morscheidt, C; Thélohan, S; Tiesler, H

    1994-01-01

    The assessment of biodurability of man-made vitreous fibers is essential to the limitation of health hazards associated with human exposure to environments in which respirable fibers are present. In vitro acellular systems provide effective test methods of measuring fiber solubility provided care is taken to select the most suitable solvent and test conditions for the specific fiber type and dimension. PMID:7882955

  9. Rapid Training System Self-Assessment

    ERIC Educational Resources Information Center

    Flesher, Jeff

    2007-01-01

    A systematic self-assessment mirrors quality system and certification models, thus making a strong argument for high-quality design, control, and management of the training function. Accomplished for the ongoing betterment of the function, not as a summative judgment of conformance, it discovers strengths and weaknesses and results in a common…

  10. Computational fluid dynamics modeling to assess the impact of roadside barriers on near-road air quality

    EPA Science Inventory

    Near-road air quality is an issue of emerging concern, with field studies consistently showing elevated air pollutant concentrations adjacent to major roads, usually decreasing to background levels within several hundred meters. Roadside barriers, both vegetative and structural, ...

  11. Analytical Assessment of the Reciprocating Feed System

    NASA Technical Reports Server (NTRS)

    Eddleman, David E.; Blackmon, James B.; Morton, Christopher D.

    2006-01-01

    A preliminary analysis tool has been created in Microsoft Excel to determine deliverable payload mass, total system mass, and performance of spacecraft systems using various types of propellant feed systems. These mass estimates are conducted by inserting into the user interface the basic mission parameters (e.g., thrust, burn time, specific impulse, mixture ratio, etc.), system architecture (e.g., propulsion system type and characteristics, propellants, pressurization system type, etc.), and design properties (e.g., material properties, safety factors, etc.). Different propellant feed and pressurization systems are available for comparison in the program. This gives the user the ability to compare conventional pressure fed, reciprocating feed system (RFS), autogenous pressurization thrust augmentation (APTA RFS), and turbopump systems with the deliverable payload, inert mass, and total system mass being the primary comparison metrics. Analyses of several types of missions and spacecraft were conducted and it was found that the RFS offers a performance improvement, especially in terms of delivered payload, over conventional pressure fed systems. Furthermore, it is competitive with a turbopump system at low to moderate chamber pressures, up to approximately 1,500 psi. Various example cases estimating the system mass and deliverable payload of several types of spacecraft are presented that illustrate the potential system performance advantages of the RFS. In addition, a reliability assessment of the RFS was conducted, comparing it to simplified conventional pressure fed and turbopump systems, based on MIL-STD 756B; these results showed that the RFS offers higher reliability, and thus substantially longer periods between system refurbishment, than turbopump systems, and is competitive with conventional pressure fed systems. This is primarily the result of the intrinsic RFS fail-operational capability with three run tanks, since the system can operate with just two run

  12. The Development of Environmental Barrier Coating Systems for SiC-SiC Ceramic Matrix Composites: Environment Effects on the Creep and Fatigue Resistance

    NASA Technical Reports Server (NTRS)

    Zhu, Dongming; Ghosn, Louis J.

    2014-01-01

    Topics covered include: Environmental barrier coating system development: needs, challenges and limitations; Advanced environmental barrier coating systems (EBCs) for CMC airfoils and combustors; NASA EBC systems and material system evolutions, Current turbine and combustor EBC coating emphases, Advanced development, processing, testing and modeling, EBC and EBC bond coats: recent advances; Design tool and life prediction of coated CMC components; Advanced CMC-EBC rig demonstrations; Summary and future directions.

  13. Assessment of zero-valent iron as a permeable reactive barrier for long-term removal of arsenic compounds from synthetic water.

    PubMed

    Lee, Kui-Jae; Lee, Yunho; Yoon, Jeyong; Kamala-Kannan, Seralathan; Park, Seung-Moon; Oh, Byung-Taek

    2009-12-01

    Zero-valent iron (ZVI) has great potential to be used as a remediation material for the removal of a wide range of pollutants from groundwater. The present study assessed the potential of ZVI for arsenic remediation by investigating (i) the removal kinetics of arsenic by ZVI in a batch reactor and (ii) the longevity of ZVI to remove arsenic in a flow-through column system which mimics the permeable reactive barrier (PRB) technology. Results of the batch experiments showed an effective removal (99.5%) of arsenic compounds from the synthetic water samples. Based on our kinetic study, the arsenic removals are expected to occur in a timescale of less than a few hours in typical PRB treatment conditions using ZVI (e.g. [ZVI] > 20 g/L and [As] < 1 mg/L). The flow-through columns were continuously operated for 360 days at a flow rate of 2 mL/h. Samples were taken at regular intervals (90, 150, 230 and 360 days) and analysed for total arsenic concentration. The removal rates decreased by (45% in aerobic and 39% in anoxic) after 360 days of operation indicate that the regular replacement of the reactive material would be required for efficient removal of arsenic.

  14. Experimental Approach to Study the Colloid Generation From the Bentonite Barrier to Quantify the Source Term and to Assess Its Relevance on the Radionuclide Migration

    SciTech Connect

    Alonso, Ursula; Missana, Tiziana; Garcia-Gutierrez, Miguel

    2007-07-01

    To guarantee the long-term safety of a high-level waste repository, all mechanisms that could affect the radionuclide (RN) migration rate must be well defined and quantified. The particular interest of this study lies on the possible contribution of bentonite colloids, generated at the compacted bentonite barrier, to RN transport. The main parameters necessary to assess the colloid-mediated transport are the source term and the stability behavior in the medium geochemical conditions. In the present work, two experimental set-ups were designed with the aim of quantifying the bentonite colloid generation rates, at laboratory scale and under 'realistic' conditions, by static hydration (no flow) of the compacted bentonite, in a confined system. Preliminary results showed that bentonite particles were generated with an average size in the colloid range, equivalent to that of bentonite colloids prepared in the laboratory. At the same time, the experimental set-up allowed performing stability studies which indicated that the colloids generated in the lower strength waters remained stable over months. The possible mechanisms responsible of colloid generation are discussed according to the obtained results in different experimental conditions. (authors)

  15. Immune cell trafficking across the barriers of the central nervous system in multiple sclerosis and stroke.

    PubMed

    Lopes Pinheiro, Melissa A; Kooij, Gijs; Mizee, Mark R; Kamermans, Alwin; Enzmann, Gaby; Lyck, Ruth; Schwaninger, Markus; Engelhardt, Britta; de Vries, Helga E

    2016-03-01

    Each year about 650,000 Europeans die from stroke and a similar number lives with the sequelae of multiple sclerosis (MS). Stroke and MS differ in their etiology. Although cause and likewise clinical presentation set the two diseases apart, they share common downstream mechanisms that lead to damage and recovery. Demyelination and axonal injury are characteristics of MS but are also observed in stroke. Conversely, hallmarks of stroke, such as vascular impairment and neurodegeneration, are found in MS. However, the most conspicuous common feature is the marked neuroinflammatory response, marked by glia cell activation and immune cell influx. In MS and stroke the blood-brain barrier is disrupted allowing bone marrow-derived macrophages to invade the brain in support of the resident microglia. In addition, there is a massive invasion of auto-reactive T-cells into the brain of patients with MS. Though less pronounced a similar phenomenon is also found in ischemic lesions. Not surprisingly, the two diseases also resemble each other at the level of gene expression and the biosynthesis of other proinflammatory mediators. While MS has traditionally been considered to be an autoimmune neuroinflammatory disorder, the role of inflammation for cerebral ischemia has only been recognized later. In the case of MS the long track record as neuroinflammatory disease has paid off with respect to treatment options. There are now about a dozen of approved drugs for the treatment of MS that specifically target neuroinflammation by modulating the immune system. Interestingly, experimental work demonstrated that drugs that are in routine use to mitigate neuroinflammation in MS may also work in stroke models. Examples include Fingolimod, glatiramer acetate, and antibodies blocking the leukocyte integrin VLA-4. Moreover, therapeutic strategies that were discovered in experimental autoimmune encephalomyelitis (EAE), the animal model of MS, turned out to be also effective in experimental

  16. Immune cell trafficking across the barriers of the central nervous system in multiple sclerosis and stroke.

    PubMed

    Lopes Pinheiro, Melissa A; Kooij, Gijs; Mizee, Mark R; Kamermans, Alwin; Enzmann, Gaby; Lyck, Ruth; Schwaninger, Markus; Engelhardt, Britta; de Vries, Helga E

    2016-03-01

    Each year about 650,000 Europeans die from stroke and a similar number lives with the sequelae of multiple sclerosis (MS). Stroke and MS differ in their etiology. Although cause and likewise clinical presentation set the two diseases apart, they share common downstream mechanisms that lead to damage and recovery. Demyelination and axonal injury are characteristics of MS but are also observed in stroke. Conversely, hallmarks of stroke, such as vascular impairment and neurodegeneration, are found in MS. However, the most conspicuous common feature is the marked neuroinflammatory response, marked by glia cell activation and immune cell influx. In MS and stroke the blood-brain barrier is disrupted allowing bone marrow-derived macrophages to invade the brain in support of the resident microglia. In addition, there is a massive invasion of auto-reactive T-cells into the brain of patients with MS. Though less pronounced a similar phenomenon is also found in ischemic lesions. Not surprisingly, the two diseases also resemble each other at the level of gene expression and the biosynthesis of other proinflammatory mediators. While MS has traditionally been considered to be an autoimmune neuroinflammatory disorder, the role of inflammation for cerebral ischemia has only been recognized later. In the case of MS the long track record as neuroinflammatory disease has paid off with respect to treatment options. There are now about a dozen of approved drugs for the treatment of MS that specifically target neuroinflammation by modulating the immune system. Interestingly, experimental work demonstrated that drugs that are in routine use to mitigate neuroinflammation in MS may also work in stroke models. Examples include Fingolimod, glatiramer acetate, and antibodies blocking the leukocyte integrin VLA-4. Moreover, therapeutic strategies that were discovered in experimental autoimmune encephalomyelitis (EAE), the animal model of MS, turned out to be also effective in experimental

  17. Hydrogen turbine power conversion system assessment

    NASA Technical Reports Server (NTRS)

    Wright, D. E.; Lucci, A. D.; Campbell, J.; Lee, J. C.

    1978-01-01

    A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system.

  18. Access to Vocational Education. A Planning System for Local Secondary and Post-Secondary Program and Facility Accessibility. Step 5: Removing Barriers.

    ERIC Educational Resources Information Center

    Rice, Eric; And Others

    This guidebook focuses on the final step included in a five-step planning system for improving local secondary and postsecondary programs and facilities accessibility: removing barriers. The guidebook is comprised of self-instructional discussions of three techniques that can be used in planning for implementation of barrier-removal strategies:…

  19. Advanced vehicle systems assessment. Volume V. Appendices

    SciTech Connect

    Not Available

    1985-03-01

    This report, which is divided into five volumes, documents the evaluation of advanced electric and hybrid vehicles for potential development by the early 1990s. The primary objective of the assessment is to recommend subsystem research priorities based on a comparison of alternatives as part of complete vehicle systems with equivalent performance. The assessment includes evaluations of candidate technologies as well as technical and economic comparisons of vehicle systems for specified missions. The availability of nonpetroleum fuel is also addressed, and preference analyses are used to assist in the evaluation of the relative merits of competing systems. Volume V, the Appendices, includes reports on battery design, battery cost, aluminum vehicle construction, IBM PC computer programs, and battery discharge models.

  20. The saturated zone at Yucca Mountain: An overview of the characterization and assessment of the saturated zone as a barrier to potential radionuclide migration

    USGS Publications Warehouse

    Eddebbarh, A.-A.; Zyvoloski, G.A.; Robinson, B.A.; Kwicklis, E.M.; Reimus, P.W.; Arnold, B.W.; Corbet, T.; Kuzio, S.P.; Faunt, C.

    2003-01-01

    The US Department of Energy is pursuing Yucca Mountain, Nevada, for the development of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste, if the repository is able to meet applicable radiation protection standards established by the US Nuclear Regulatory Commission and the US Environmental Protection Agency (EPA). Effective performance of such a repository would rely on a number of natural and engineered barriers to isolate radioactive waste from the accessible environment. Groundwater beneath Yucca Mountain is the primary medium through which most radionuclides might move away from the potential repository. The saturated zone (SZ) system is expected to act as a natural barrier to this possible movement of radionuclides both by delaying their transport and by reducing their concentration before they reach the accessible environment. Information obtained from Yucca Mountain Site Characterization Project activities is used to estimate groundwater flow rates through the site-scale SZ flow and transport model area and to constrain general conceptual models of groundwater flow in the site-scale area. The site-scale conceptual model is a synthesis of what is known about flow and transport processes at the scale required for total system performance assessment of the site. This knowledge builds on and is consistent with knowledge that has accumulated at the regional scale but is more detailed because more data are available at the site-scale level. The mathematical basis of the site-scale model and the associated numerical approaches are designed to assist in quantifying the uncertainty in the permeability of rocks in the geologic framework model and to represent accurately the flow and transport processes included in the site-scale conceptual model. Confidence in the results of the mathematical model was obtained by comparing calculated to observed hydraulic heads, estimated to measured permeabilities, and lateral flow rates

  1. The saturated zone at Yucca Mountain: an overview of the characterization and assessment of the saturated zone as a barrier to potential radionuclide migration

    NASA Astrophysics Data System (ADS)

    Eddebbarh, A. A.; Zyvoloski, G. A.; Robinson, B. A.; Kwicklis, E. M.; Reimus, P. W.; Arnold, B. W.; Corbet, T.; Kuzio, S. P.; Faunt, C.

    2003-05-01

    The US Department of Energy is pursuing Yucca Mountain, Nevada, for the development of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste, if the repository is able to meet applicable radiation protection standards established by the US Nuclear Regulatory Commission and the US Environmental Protection Agency (EPA). Effective performance of such a repository would rely on a number of natural and engineered barriers to isolate radioactive waste from the accessible environment. Groundwater beneath Yucca Mountain is the primary medium through which most radionuclides might move away from the potential repository. The saturated zone (SZ) system is expected to act as a natural barrier to this possible movement of radionuclides both by delaying their transport and by reducing their concentration before they reach the accessible environment. Information obtained from Yucca Mountain Site Characterization Project activities is used to estimate groundwater flow rates through the site-scale SZ flow and transport model area and to constrain general conceptual models of groundwater flow in the site-scale area. The site-scale conceptual model is a synthesis of what is known about flow and transport processes at the scale required for total system performance assessment of the site. This knowledge builds on and is consistent with knowledge that has accumulated at the regional scale but is more detailed because more data are available at the site-scale level. The mathematical basis of the site-scale model and the associated numerical approaches are designed to assist in quantifying the uncertainty in the permeability of rocks in the geologic framework model and to represent accurately the flow and transport processes included in the site-scale conceptual model. Confidence in the results of the mathematical model was obtained by comparing calculated to observed hydraulic heads, estimated to measured permeabilities, and lateral flow rates

  2. Statutory and Regulatory Barriers to Greater Efficiencies in the Arizona University System.

    ERIC Educational Resources Information Center

    Johnson, Edward

    One of the working papers in the final report of the Arizona Board of Regents' Task Force on Excellence, Efficiency and Competitiveness, this document organizes the responses of Arizona's universities to questions on statutory and regulatory barriers to greater efficiency. Each statute, regulation, or policy is noted with commentary and…

  3. Assessment of reservoir system variable forecasts

    NASA Astrophysics Data System (ADS)

    Kistenmacher, Martin; Georgakakos, Aris P.

    2015-05-01

    Forecast ensembles are a convenient means to model water resources uncertainties and to inform planning and management processes. For multipurpose reservoir systems, forecast types include (i) forecasts of upcoming inflows and (ii) forecasts of system variables and outputs such as reservoir levels, releases, flood damage risks, hydropower production, water supply withdrawals, water quality conditions, navigation opportunities, and environmental flows, among others. Forecasts of system variables and outputs are conditional on forecasted inflows as well as on specific management policies and can provide useful information for decision-making processes. Unlike inflow forecasts (in ensemble or other forms), which have been the subject of many previous studies, reservoir system variable and output forecasts are not formally assessed in water resources management theory or practice. This article addresses this gap and develops methods to rectify potential reservoir system forecast inconsistencies and improve the quality of management-relevant information provided to stakeholders and managers. The overarching conclusion is that system variable and output forecast consistency is critical for robust reservoir management and needs to be routinely assessed for any management model used to inform planning and management processes. The above are demonstrated through an application from the Sacramento-American-San Joaquin reservoir system in northern California.

  4. Exploring Barriers of the Health System to Rehabilitation Services for People with Disabilities in Iran: A Qualitative Study

    PubMed Central

    Abdi, Kianoush; Arab, Mohammad; Rashidian, Arash; Kamali, Mohammad; Khankeh, Hamid Reza; Farahani, Farideh Khalajabadi

    2015-01-01

    Introduction The United Nations (UN) identified health as a basic human right, but, unfortunately, the evidence shows that people with disabilities (PWD) often have lower levels of health than the general population. This can be associated with problems in access to the services and programs. The aim of this study was to explore barriers of the health system to rehabilitation services for PWD in Iran. Methods This was a qualitative study conducted on 21 participants using semi-structured, in-depth interviews and content analysis from June 2014 to July 2015. Data analysis was performed by MAXQDA version 10. Results “Barriers” were the most prominent challenge of people with disabilities that needed access to rehabilitation services. These barriers were categorized into eight concepts of deficiency in the system that provides rehabilitation services, defect of education, deficiency in detecting and screening of people with disability, defect of stewardship in rehabilitation, ignoring socio-cultural factors, accessibility hardships, lack of identification, and financial hardships in rehabilitation. Conclusions An efficient rehabilitation plan requires a common understanding, considering the long-term complications involved in addressing the barriers. Understanding the barriers of the health system to rehabilitation services requires comprehensive management that first should be familiar with all of PWD, providers, policy makers, and other beneficiaries. It also is necessary for policy makers to consider rehabilitation services as a main part of the health plan; especially, they must change their oversight of rehabilitation services and programs. Thus, policy makers should have need comprehensive management and recommended further research. PMID:26767101

  5. Association of individual and systemic barriers to optimal medical care in people living with HIV/AIDS in Miami-Dade County.

    PubMed

    Wawrzyniak, Andrew J; Rodríguez, Allan E; Falcon, Anthony E; Chakrabarti, Anindita; Parra, Alexa; Park, Jane; Mercogliano, Kathleen; Villamizar, Kira; Kolber, Michael A; Feaster, Daniel J; Metsch, Lisa R

    2015-05-01

    Barriers to retention in HIV care are detrimental to patients' progress along the HIV continuum of care. Previous literature has focused on individual, client-level barriers, and interventions to address them. In contrast, less work has examined the role of system-level barriers on HIV care outcomes. This study seeks to understand how individual and systemic barriers individually are associated with clinic appointment attendance and virologic suppression in HIV-infected patients attending the largest HIV clinic in Miami-Dade, FL. In addition, we examined the synergistic effects of these barriers as potential syndemic factors on these health outcomes. Barriers to clinic attendance were determined in a face-to-face study interview with 444 HIV-infected outpatients (187 regular attenders, 191 irregular attenders, and 66 nonattenders) identified from electronic medical records. Compared with the other attendance groups, nonattenders had higher viral loads, were less likely to be virologically suppressed, had lower CD4 counts, had higher depressive symptoms, life chaos, lower quality of life, and higher rates of food insecurity, and recent drug use. Additionally, nonattenders compared with regular attenders had lower physician relationship ratings, had lower medical information clarity and more often reported transportation as a barrier to clinic attendance. When viewed as a syndemic, compared with patients not reporting any barriers, patients with 3 or more individual-level barriers were more likely to have a detectable viral load (odds ratio = 3.60, 95% CI: 1.71 to 7.61). Our findings suggest that patients presenting to the clinic with multiple barriers should be prioritized for assistance and future interventions to improve retention in care. Interventions should address multiple individual and system-level barriers simultaneously with particular attention to addressing depressive symptoms, organizational skills, relationship with the physician, and HIV

  6. The Association of Individual and Systemic Barriers to Optimal Medical Care in People Living with HIV/AIDS (PLWHA) in Miami-Dade County

    PubMed Central

    Wawrzyniak, Andrew J.; Rodríguez, Allan E.; Falcon, Anthony E.; Chakrabarti, Anindita; Parra, Alexa; Park, Jane; Mercogliano, Kathleen; Villamizar, Kira; Kolber, Michael A.; Feaster, Daniel J.; Metsch, Lisa R.

    2015-01-01

    Barriers to retention in HIV care are detrimental to patients’ progress along the HIV continuum of care. Previous literature has focused on individual, client-level barriers and interventions to address them. In contrast, less work has examined the role of system-level barriers on HIV care outcomes. The present study seeks to understand how individual and systemic barriers individually are associated with clinic appointment attendance and virologic suppression in HIV-infected patients attending the largest HIV clinic in Miami-Dade, Florida. In addition, we examined the synergistic effects of these barriers as potential syndemic factors on these health outcomes. Barriers to clinic attendance were determined in a face-to-face study interview with 444 HIV-infected outpatients (187 regular attenders, 191 irregular attenders, 66 non-attenders) identified from electronic medical records. Compared to the other attendance groups, non-attenders had higher viral loads, were less likely to be virologically suppressed, had lower CD4 counts, had higher depressive symptoms, life chaos, lower quality of life, and higher rates of food insecurity and recent drug use. Additionally, non-attenders compared to regular attenders had lower physician relationship ratings, had lower medical information clarity, and more often reported transportation as a barrier to clinic attendance. When viewed as a syndemic, compared to patients not reporting any barriers, patients with three or more individual-level barriers were more likely to have a detectable viral load (OR = 3.60, 95%CI [1.71, 7.61]). Our findings suggest that patients presenting to the clinic with multiple barriers should be prioritized for assistance and future interventions to improve retention in care. Interventions should address multiple individual and system level barriers simultaneously with particular attention to addressing depressive symptoms, organizational skills, relationship with the physician, and HIV

  7. Review and assessment of information kiosk systems

    SciTech Connect

    Hill, E.

    1997-03-01

    This report reviews the current state-of-the-art and assesses the progress that is being made in kiosk information systems. This information will be used in developing a kiosk system for the Metro Dade Transit (MDTA), which has recently been awarded a Federal Transit Administration (FTA) operational test grant to develop an informational kiosk prototype at major rail and bus transfer points. A literature review of the Intelligent Transportation Systems (ITS) American National Clearinghouse and FTA`s Advanced Public Transportation Systems project summaries revealed kiosk projects at several transit agencies. These transit agencies were surveyed to gather information about kiosk technology. This survey provided the information about kiosk systems deployed or tested at transit agencies.

  8. Slowly released molasses barrier system for controlling nitrate plumes in groundwater: a pilot-scale tank study.

    PubMed

    Lee, Byung Sun; Lee, Kyuyeon; Um, Jae Yeon; Nam, Kyoungphile

    2014-02-01

    A well-type barrier system containing solidified molasses as a reactive medium was developed to promote the indigenous denitrifying activity and to treat nitrate plumes in groundwater. Three slowly released molasses (SRM) barrier systems harboring 60, 120, and 120 SRM rods, which were named System A, B, and C, respectively, were operated to examine nitrate removal efficiency in a pilot-scale sandy tank. These SRM systems induced a consistent removal of nitrate without pore clogging and hydraulic disturbance during the test period. The initial nitrate concentration was 142mgL(-1), and the concentrations decreased by 80%, 84%, and 79% in System A, B, and C, respectively. In particular, System C was inoculated with heterotrophic denitrifiers, but the nitrate removal efficiency was not enhanced compared to System B, probably due to the prior existence of indigenous denitrifiers in the sandy tank. The presence of nitrite reductase-encoding gene (i.e. nirK) at the site was confirmed by denatured gradient gel electrophoresis analysis.

  9. Numerical determination of the interfacial energy and nucleation barrier of curved solid-liquid interfaces in binary systems.

    PubMed

    Kundin, Julia; Choudhary, Muhammad Ajmal

    2016-07-01

    The phase-field crystal (PFC) technique is a widely used approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a two-dimensional PFC model for a binary system based on the work of Elder et al. [Phys. Rev. B 75, 064107 (2007)PRBMDO1098-012110.1103/PhysRevB.75.064107] to study the effect of the curved, diffuse solid-liquid interface on the interfacial energy as well as the nucleation barrier. The calculation of the interfacial energy and the nucleation barrier certainly depends on the proper definition of the solid-liquid dividing surface and the corresponding nucleus size. We define the position of the sharp interface at which the interfacial energy is to be evaluated by using the concept of equimolar dividing surface (r^{e}) and the minimization of the interfacial energy (r^{s}). The comparison of the results based on both radii shows that the difference r^{e}-r^{s} is always positive and has a limit for large cluster sizes which is comparable to the Tolman length. Furthermore, we found the real nucleation barrier for small cluster sizes, which is defined as a function of the radius r^{s}, and compared it with the classical nucleation theory. The simulation results also show that the extracted interfacial energy as function of both radii is independent of system size, and this dependence can be reasonably described by the nonclassical Tolman formula with a positive Tolman length.

  10. Numerical determination of the interfacial energy and nucleation barrier of curved solid-liquid interfaces in binary systems

    NASA Astrophysics Data System (ADS)

    Kundin, Julia; Choudhary, Muhammad Ajmal

    2016-07-01

    The phase-field crystal (PFC) technique is a widely used approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a two-dimensional PFC model for a binary system based on the work of Elder et al. [Phys. Rev. B 75, 064107 (2007), 10.1103/PhysRevB.75.064107] to study the effect of the curved, diffuse solid-liquid interface on the interfacial energy as well as the nucleation barrier. The calculation of the interfacial energy and the nucleation barrier certainly depends on the proper definition of the solid-liquid dividing surface and the corresponding nucleus size. We define the position of the sharp interface at which the interfacial energy is to be evaluated by using the concept of equimolar dividing surface (re) and the minimization of the interfacial energy (rs). The comparison of the results based on both radii shows that the difference re-rs is always positive and has a limit for large cluster sizes which is comparable to the Tolman length. Furthermore, we found the real nucleation barrier for small cluster sizes, which is defined as a function of the radius rs, and compared it with the classical nucleation theory. The simulation results also show that the extracted interfacial energy as function of both radii is independent of system size, and this dependence can be reasonably described by the nonclassical Tolman formula with a positive Tolman length.

  11. SCC-DFTB Energy Barriers for Single and Double Proton Transfer Processes in the Model Molecular Systems Malonaldehyde and Porphycene

    SciTech Connect

    Walewski, L.; Krachtus, D; Fischer, S.; Smith, Jeremy C; Bala, P.; Lesyng, B.

    2005-09-01

    Self-consistent charge-density functional tight-binding SCC-DFTB is a computationally efficient method applicable to large (bio)molecular systems in which (bio)chemical reactions may occur. Among these reactions are proton transfer processes. This method, along with more advanced ab initio techniques, is applied in this study to compute intramolecular barriers for single and double proton transfer processes in the model systems, malonaldehyde and porphycene, respectively. SCC-DFTB is compared with experimental data and higher-level ab initio calculations. For malonaldehyde, the SCC-DFTB barrier height is 3.1 kcal/mol in vacuo and 4.2 kcal/mol in water solution. In the case of porphycene, the minimum energy pathways for double intramolecular proton transfer were determined using the conjugate peak refinement (CPR) method. Six isomers of porphycene were ordered according to energy. The only energetically allowed pathway was found to connect two symmetrical trans states via an unstable cis-A isomer. The SCC-DFTB barrier heights are 11.1 kcal/mol for the trans-cis-A process, and 7.4 kcal/mol for the reverse cis-A-trans one with the energy difference of 3.7 kcal/mol between the trans- and cis-A states. The method provides satisfactory energy results when compared with reference ab initio and experimental data.

  12. EFFECTS OF NUCLEAR INDUCED BREAKUP ON THE FUSION OF 6Li+12C AND 6He+12C SYSTEMS AROUND BARRIER ENERGIES

    NASA Astrophysics Data System (ADS)

    Duhan, Sukhvinder S.; Singh, Manjeet; Kharab, Rajesh

    2012-06-01

    We have studied the effects of nuclear induced breakup channel coupling on the fusion cross-section for 6Li+12C and 6He+12C systems in the near barrier energy regime using the dynamic polarization potential (DPP) approach. It has been found that there is enhancement in the fusion cross-section with respect to standard one-dimensional barrier penetration model in the below barrier energy regime while at energies above the barrier there is suppression of fusion cross-section with respect to simple barrier penetration model is observed. The agreement between data and predictions for 6Li+12C system improves significantly as a result of the inclusion of nuclear induced DPP.

  13. From the Blood to the Central Nervous System: A Nanoparticle's Journey Through the Blood-Brain Barrier by Transcytosis.

    PubMed

    Fullstone, G; Nyberg, S; Tian, X; Battaglia, G

    2016-01-01

    Designing nanoparticles that effectively enter the central nervous system (CNS) rapidly and without alteration is one of the major challenges in the use of nanotechnology for the brain. In this chapter, we explore the process of transcytosis, a receptor-mediated transport pathway that permits endogenous macromolecules to enter the CNS by crossing the blood-brain barrier. Transcytosis across the blood-brain barrier involves a number of distinct stages, including receptor binding, endocytosis into a transport vesicle, trafficking of the vesicle to the opposite side of the cell, and finally exocytosis and release of cargo. For each stage, we discuss the current knowledge on biological, physiological, and physical factors that influence nanoparticle transit through that stage of transcytosis, with implications for nanoparticle design. Finally, we look at the current progress in designing nanoparticles that exploit transcytosis for CNS delivery. PMID:27678174

  14. Assessing loss of coral cover on Australia's Great Barrier Reef over two decades, with implications for longer-term trends

    NASA Astrophysics Data System (ADS)

    Sweatman, H.; Delean, S.; Syms, C.

    2011-06-01

    While coral reefs in many parts of the world are in decline as a direct consequence of human pressures, Australia's Great Barrier Reef (GBR) is unusual in that direct human pressures are low and the entire system of ~2,900 reefs has been managed as a marine park since the 1980s. In spite of these advantages, standard annual surveys of a large number of reefs showed that from 1986 to 2004, average live coral cover across the GBR declined from 28 to 22%. This overall decline was mainly due to large losses in six (21%) of 29 subregions. Declines in live coral cover on reefs in two inshore subregions coincided with thermal bleaching in 1998, while declines in four mid-self subregions were due to outbreaks of predatory starfish. Otherwise, living coral cover increased in one subregion (3%) and 22 subregions (76%) showed no substantial change. Reefs in the great majority of subregions showed cycles of decline and recovery over the survey period, but with little synchrony among subregions. Two previous studies examined long-term changes in live coral cover on GBR reefs using meta-analyses including historical data from before the mid-1980s. Both found greater rates of loss of coral and recorded a marked decrease in living coral cover on the GBR in 1986, coinciding exactly with the start of large-scale monitoring. We argue that much of the apparent long-term decrease results from combining data from selective, sparse, small-scale studies before 1986 with data from both small-scale studies and large-scale monitoring surveys after that date. The GBR has clearly been changed by human activities and live coral cover has declined overall, but losses of coral in the past 40-50 years have probably been overestimated.

  15. Blood-brain barrier in vitro models as tools in drug discovery: assessment of the transport ranking of antihistaminic drugs.

    PubMed

    Neuhaus, W; Mandikova, J; Pawlowitsch, R; Linz, B; Bennani-Baiti, B; Lauer, R; Lachmann, B; Noe, C R

    2012-05-01

    In the course of our validation program testing blood-brain barrier (BBB) in vitro models for their usability as tools in drug discovery it was evaluated whether an established Transwell model based on porcine cell line PBMEC/C1-2 was able to differentiate between the transport properties of first and second generation antihistaminic drugs. First generation antihistamines can permeate the BBB and act in the central nervous system (CNS), whereas entry to the CNS of second generation antihistamines is restricted by efflux pumps such as P-glycoprotein (P-gP) located in brain endothelial cells. P-gP functionality of PBMEC/C1-2 cells grown on Transwell filter inserts was proven by transport studies with P-gP substrate rhodamine 123 and P-gP blocker verapamil. Subsequent drug transport studies with the first generation antihistamines promethazine, diphenhydramine and pheniramine and the second generation antihistamines astemizole, ceterizine, fexofenadine and loratadine were accomplished in single substance as well as in group studies. Results were normalised to diazepam, an internal standard for the transcellular transport route. Moreover, effects after addition of P-gP inhibitor verapamil were investigated. First generation antihistamine pheniramine permeated as fastest followed by diphenhydramine, diazepam, promethazine and second generation antihistaminic drugs ceterizine, fexofenadine, astemizole and loratadine reflecting the BBB in vivo permeability ranking well. Verapamil increased the transport rates of all second generation antihistamines, which suggested involvement of P-gP during their permeation across the BBB model. The ranking after addition of verapamil was significantly changed, only fexofenadine and ceterizine penetrated slower than internal standard diazepam in the presence of verapamil. In summary, permeability data showed that the BBB model based on porcine cell line PBMEC/C1-2 was able to reflect the BBB in vivo situation for the transport of

  16. Health system barriers and facilitators to medication adherence for the secondary prevention of cardiovascular disease: a systematic review

    PubMed Central

    Banerjee, Amitava; Khandelwal, Shweta; Nambiar, Lavanya; Saxena, Malvika; Peck, Victoria; Moniruzzaman, Mohammed; Faria Neto, Jose Rocha; Quinto, Katherine Curi; Smyth, Andrew; Leong, Darryl; Werba, José Pablo

    2016-01-01

    Background Secondary prevention is cost-effective for cardiovascular disease (CVD), but uptake is suboptimal. Understanding barriers and facilitators to adherence to secondary prevention for CVD at multiple health system levels may inform policy. Objectives To conduct a systematic review of barriers and facilitators to adherence/persistence to secondary CVD prevention medications at health system level. Methods Included studies reported effects of health system level factors on adherence/persistence to secondary prevention medications for CVD (coronary artery or cerebrovascular disease). Studies considered at least one of β blockers, statins, angiotensin–renin system blockers and aspirin. Relevant databases were searched from 1 January 1966 until 1 October 2015. Full texts were screened for inclusion by 2 independent reviewers. Results Of 2246 screened articles, 25 studies were included (12 trials, 11 cohort studies, 1 cross-sectional study and 1 case–control study) with 132 140 individuals overall (smallest n=30, largest n=63 301). 3 studies included upper middle-income countries, 1 included a low middle-income country and 21 (84%) included high-income countries (9 in the USA). Studies concerned established CVD (n=4), cerebrovascular disease (n=7) and coronary heart disease (n=14). Three studies considered persistence and adherence. Quantity and quality of evidence was limited for adherence, persistence and across drug classes. Studies were concerned with governance and delivery (n=19, including 4 trials of fixed-dose combination therapy, FDC), intellectual resources (n=1), human resources (n=1) and health system financing (n=4). Full prescription coverage, reduced copayments, FDC and counselling were facilitators associated with higher adherence. Conclusions High-quality evidence on health system barriers and facilitators to adherence to secondary prevention medications for CVD is lacking, especially for low-income settings. Full prescription coverage

  17. An assessment of EIA system in India

    SciTech Connect

    Panigrahi, Jitendra K.; Amirapu, Susruta

    2012-07-15

    Environmental impact assessment (EIA) was first introduced in India based on the Environmental Protection Act (EPA), 1986. But formally it came in to effect, when Ministry of Environment and Forest (MoEF) has passed a major legislative measure under EPA in January 1994 for Environmental Clearance (EC) known as EIA Notification, 1994. Subsequently, EIA processes have been strengthened by MoEF by a series of amendments. The current practice is adhering to EIA Notification, 2006 and its amendments. The pieces of evidence collected and analysis in the present assessment suggest that, despite a sound legislative, administrative and procedural set-up EIA has not yet evolved satisfactorily in India. An appraisal of the EIA system against systematic evaluation criteria, based on discussions with various stakeholders, EIA expert committee members, approval authorities, project proponents, NGOs and consulting professionals, reveals various drawbacks of the EIA system. These mainly include; inadequate capacity of EIA approval authorities, deficiencies in screening and scoping, poor quality EIA reports, inadequate public participation and weak monitoring. Overall, EIA is used presently as a project justification tool rather than as a project planning tool to contribute to achieving sustainable development. While shortcomings are challenging, Government of India is showing a high degree of commitment. The EIA system in the country is undergoing progressive refinements by steadily removing the constraints. The paper identifies opportunities for taking advantage of the current circumstances for strengthening the EIA process. - Highlights: Black-Right-Pointing-Pointer An assessment has been carried out on Environmental Clearance under EIA Notification, 2006, MoEF, Government of India. Black-Right-Pointing-Pointer EIA system is appraised against systematic evaluation criteria proposed by Ahmad and Wood (2002), Wood (2003), Fuller (1999). Black-Right-Pointing-Pointer The analysis

  18. Systems engineering process and organization assessment

    NASA Technical Reports Server (NTRS)

    Batson, Robert G.

    1992-01-01

    The purpose of this report is to briefly summarize the results of an eight week assessment of NASA/MSFC Phase A and Phase B systems engineering processes, methodologies, and activities. Specifically, fourteen inconsistencies or weaknesses were identified and recommendations for corrective action were generated. A 1.5 hour briefing on these results was given in EL51 on 8-11-92; that documentation is available from the author or either NASA Colleague.

  19. Software quality assessment for health care systems.

    PubMed

    Braccini, G; Fabbrini, F; Fusani, M

    1997-01-01

    The problem of defining a quality model to be used in the evaluation of the software components of a Health Care System (HCS) is addressed. The model, based on the ISO/IEC 9126 standard, has been interpreted to fit the requirements of some classes of applications representative of Health Care Systems, on the basis of the experience gained both in the field of medical Informatics and assessment of software products. The values resulting from weighing the quality characteristics according to their criticality outline a set of quality profiles that can be used both for evaluation and certification.

  20. Code System for Seismic Probabilistic Risk Assessment.

    2001-03-27

    Version 00 SEISIM1 calculates the probabilities of seismically induced failures for components and systems and propagates these calculations to determine the probability of accident sequences and the resulting total risk, which is quantified as an expected value of radiation release and exposure from a given nuclear power plant. SEISIM1 was developed as a fundamental tool for the systems analysis portion of the NRC's Seismic Safety Margins Research Program (SSMRP). The SSMRP provides a complete, self-containedmore » methodology to assess and quantify the risk to nuclear power plants from seismic events and seismically induced failures.« less

  1. A controlled-release molasses barrier system for controlling nitrate plume in groundwater: A large flow-tank study

    NASA Astrophysics Data System (ADS)

    Lee, B. S.; Um, J. Y.; Lee, K. Y.; Kim, Y. B.; Nam, K.; Woo, N. C.; Kim, J. H.; Lee, J. M.

    2009-04-01

    A well-type permeable barrier system containing controlled-release molasses as a reactive material to promote the indigenous denitrifying activity (termed CRM system hereafter) has been developed for controlling nitrate plume in groundwater. To control the release of molasses as an extra carbon and energy source, CRM rod (OD x L = 4 cm x 30 cm) was manufactured using molding technique by dispersing molasses in paraffin wax-cellulose-silica matrix. A large scale flow-tank (L x W x D = 8 m x 4 m x 1 m, 95 m3 of sands, porosity of 0.45) was prepared to test the CRM system (L x W x D = 3 m x 4 m x 1 m) in destroying nitrate, which was consisted of three layers of discrete barriers installed at 1-m interval. Nitrate plume (1.2 m/d of velocity, 142 mg/L of nitrate) was generated by introducing both tap water (1.1 m3/d) and diluted nitrate solution (0.5 m3/d, 312 mg/L of nitrate) daily. Changes in nitrate concentrations were monitored at 30 monitoring points across the flow-tank. For 14 (i.e., the first test), 21 (i.e., the second test), and 42 (i.e., the third test) days, 80, 140, and 140 CRM rods were placed into the barriers to construct the CRM system, respectively. An indigenous microorganism Ensifer adhaerens (97% similarity) was identified from the flow-tank sands, which was probably the main denitrifier in the system. After the second test, a heterotrophic denitrifier Pseudomonas sp. KY1 was inoculated to increase destruction efficiency into the flow-tank sands for the third test. For the first test, nitrate concentrations decreased by 29, 59, and 80% after the 1st, 2nd, and 3rd barriers, respectively. For the second and third tests, nitrate concentrations decreased by 32 and 26% for the 1st, 68 and 74% for the 2nd, and 84 and 81% for the 3rd barrier, indicating little effects of inoculating KY1 on destruction efficiencies. At 5.5 m downstream (i.e., 1.75 m behind the 3rd barrier), nitrate concentrations decreased by 81, 90, and 90% at the first, second, and third

  2. Advanced turbine systems-research and development thermal barrier coatings technology: 1st bimonthly report, December 1995

    SciTech Connect

    1995-12-01

    Objective is development of ultra-high efficient, environmentally superior, and cost-competitive gas turbine systems. Operating profiles of these industrial gas turbines are long, less cyclic, with fewer transients than in aircraft gas turbine engines. Durability and performance demands of ATS can be achieved reduction of metal temperatures, and this can be accomplished by applying thermal barrier coatings (TBCs) onto the substrate. Phase I and II are discussed; TBC systems will be selected for application on blades for hot section specimen bench test in Phase III.

  3. Nuclear rainbow in the 16O + 27AL system: The role of couplings at energies far above the barrier

    NASA Astrophysics Data System (ADS)

    Pereira, D.; Linares, R.; Oliveira, J. R. B.; Lubian, J.; Chamon, L. C.; Gomes, P. R. S.; Cunsolo, A.; Cappuzzello, F.; Cavallaro, M.; Carbone, D.; Foti, A.

    2012-04-01

    High precision elastic and inelastic angular distributions have been measured for the 16O + 27Al system at a beam energy of 100 MeV. The data analysis confirms a rainbow formation as already predicted by parameter-free Coupled Channel calculations. It also helps to reveal the crucial role of inelastic couplings in the rainbow formation for heavier systems even at energies far above the Coulomb barrier. This feature, well known in atomic/molecular scattering, is experimentally studied for the first time in Nuclear Physics.

  4. System Study: Technology Assessment and Prioritizing

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The objective of this NASA funded project is to assess and prioritize advanced technologies required to achieve the goals for an "Intelligent Propulsion System" through collaboration among GEAE, NASA, and Georgia Tech. Key GEAE deliverables are parametric response surface equations (RSE's) relating technology features to system benefits (sfc, weight, fuel burn, design range, acoustics, emission, etc...) and listings of Technology Impact Matrix (TIM) with benefits, debits, and approximate readiness status. TIM has been completed for GEAE and NASA proposed technologies. The combined GEAE and NASA TIM input requirement is shown in Table.1. In the course of building the RSE's and TIM, significant parametric technology modeling and RSE accuracy improvements were accomplished. GEAE has also done preliminary ranking of the technologies using Georgia Tech/GEAE USA developed technology evaluation tools. System level impact was performed by combining beneficial technologies with minimum conflict among various system figures of merits to assess their overall benefits to the system. The shortfalls and issues with modeling the proposed technologies are identified, and recommendations for future work are also proposed.

  5. Internal Film Receiver systems assessment study

    SciTech Connect

    Anderson, J.V.

    1988-03-01

    This report documents SERI's Internal Film Receiver (IFR) design study and system assessment effort; and it compares the performance and economic potential of this system to conventional salt-in-tube receivers and to systems with the direct absorption receiver (DAR). SPECO, Inc., under contract to SERI, performed the receiver configuration work and their final report is included as Appendix A. The IFR is similar to the DAR in that both use films flowing over nearly vertical plates to absorb the solar energy. However, in the IFR the radiation strikes the outside of the absorber plate and the working fluid flows down the inside. The results of the system-level assessment indicate that the IFR concept has the potential to deliver levelized energy costs (LEC) on the order of 5%--7% lower than the salt-in-tube receiver. Although the potential economic benefits of the IFR are not as great as those for the DAR, which shows more than a 15% improvement in LEC over the salt-in-tube receiver system, this may be offset by the lower technical risks with the IFR. 3 refs., 2 figs., 7 tabs.

  6. A noise assessment and prediction system

    NASA Astrophysics Data System (ADS)

    Olsen, Robert O.; Noble, John M.

    1990-12-01

    A system has been designed to provide an assessment of noise levels that result from testing activities at Aberdeen Proving Ground, Md. The system receives meteorological data from surface stations and an upper air sounding system. The data from these systems are sent to a meteorological model, which provides forecasting conditions for up to three hours from the test time. The meteorological data are then used as input into an acoustic ray trace model which projects sound level contours onto a two-dimensional display of the surrounding area. This information is sent to the meteorological office for verification, as well as the range control office, and the environmental office. To evaluate the noise level predictions, a series of microphones are located off the reservation to receive the sound and transmit this information back to the central display unit. The computer models are modular allowing for a variety of models to be utilized and tested to achieve the best agreement with data. This technique of prediction and model validation will be used to improve the noise assessment system.

  7. A noise assessment and prediction system

    NASA Technical Reports Server (NTRS)

    Olsen, Robert O.; Noble, John M.

    1990-01-01

    A system has been designed to provide an assessment of noise levels that result from testing activities at Aberdeen Proving Ground, Md. The system receives meteorological data from surface stations and an upper air sounding system. The data from these systems are sent to a meteorological model, which provides forecasting conditions for up to three hours from the test time. The meteorological data are then used as input into an acoustic ray trace model which projects sound level contours onto a two-dimensional display of the surrounding area. This information is sent to the meteorological office for verification, as well as the range control office, and the environmental office. To evaluate the noise level predictions, a series of microphones are located off the reservation to receive the sound and transmit this information back to the central display unit. The computer models are modular allowing for a variety of models to be utilized and tested to achieve the best agreement with data. This technique of prediction and model validation will be used to improve the noise assessment system.

  8. Blanch Resistant and Thermal Barrier NiAl Coating Systems for Advanced Copper Alloys

    NASA Technical Reports Server (NTRS)

    Raj, Sai V. (Inventor)

    2005-01-01

    A method of forming an environmental resistant thermal barrier coating on a copper alloy is disclosed. The steps include cleansing a surface of a copper alloy, depositing a bond coat on the cleansed surface of the copper alloy, depositing a NiAl top coat on the bond coat and consolidating the bond coat and the NiAl top coat to form the thermal barrier coating. The bond coat may be a nickel layer or a layer composed of at least one of copper and chromium-copper alloy and either the bond coat or the NiAl top coat or both may be deposited using a low pressure or vacuum plasma spray.

  9. Manifolds and front propagation barriers in advection-reaction-diffusion systems

    NASA Astrophysics Data System (ADS)

    Solomon, Tom

    2015-03-01

    We present experiments on the propagation of reaction fronts in laminar, vortex-dominated flows. The fronts are produced by the excitable Belousov-Zhabotinsky chemical reaction. The flows studied are driven by magnetohydrodynamic forcing techniques and are composed of a single vortex, chains or arrays of vortices, or spatially-disordered flows. In all of these cases, one-way barriers appear that either inhibit front propagation or, in some cases, pin the reactions fronts. We analyze this behavior with a recent theory of burning invariant manifolds (BIMs) that are a generalization of the theory of invariant manifolds developed in the past to characterize chaotic mixing and transport of passive impurities. We demonstrate that the BIMs are responsible for the reaction barriers observed experimentally, and we discuss the applicability of this BIM formalism to a range of flows: time-independent, time-periodic and time-aperiodic. Supported by NSF Grants DMR-1004744, DMR-1361881 and PHY-1156964.

  10. Artificial disbonds for calibration of transient thermography inspection of thermal barrier coating systems

    NASA Astrophysics Data System (ADS)

    Ptaszek, Grzegorz; Cawley, Peter; Almond, Darryl; Pickering, Simon

    2012-05-01

    Transient thermography is commonly used for the detection of disbonds in thermal barrier coatings (TBC). As for other NDT techniques, reference test specimens are required for calibration, but unfortunately, real disbonds are very difficult to use because it is difficult to control their size, and larger ones tend to spall. Flat bottomed holes are commonly used, but these over-estimate the thermal contrast obtained for a defect of a given diameter. This paper quantifies the difference, and proposes an artificial disbond.

  11. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a

  12. Security barriers with automated reconnaissance

    SciTech Connect

    McLaughlin, James O; Baird, Adam D; Tullis, Barclay J; Nolte, Roger Allen

    2015-04-07

    An intrusion delaying barrier includes primary and secondary physical structures and can be instrumented with multiple sensors incorporated into an electronic monitoring and alarm system. Such an instrumented intrusion delaying barrier may be used as a perimeter intrusion defense and assessment system (PIDAS). Problems with not providing effective delay to breaches by intentional intruders and/or terrorists who would otherwise evade detection are solved by attaching the secondary structures to the primary structure, and attaching at least some of the sensors to the secondary structures. By having multiple sensors of various types physically interconnected serves to enable sensors on different parts of the overall structure to respond to common disturbances and thereby provide effective corroboration that a disturbance is not merely a nuisance or false alarm. Use of a machine learning network such as a neural network exploits such corroboration.

  13. Intestinal barrier analysis by assessment of mucins, tight junctions, and α-defensins in healthy C57BL/6J and BALB/cJ mice.

    PubMed

    Volynets, Valentina; Rings, Andreas; Bárdos, Gyöngyi; Ostaff, Maureen J; Wehkamp, Jan; Bischoff, Stephan C

    2016-01-01

    The intestinal barrier is gaining increasing attention because it is related to intestinal homeostasis and disease. Different parameters have been used in the past to assess intestinal barrier functions in experimental studies; however most of them are poorly defined in healthy mice. Here, we compared a number of barrier markers in healthy mice, established normal values and correlations. In 48 mice (24 C57BL/6J, 24 BALB/cJ background), we measured mucus thickness, and expression of mucin-2, α-defensin-1 and -4, zonula occludens-1, occludin, junctional adhesion molecule-A, claudin-1, 2 and -5. We also analyzed claudin-3 and fatty acid binding protein-2 in urine and plasma, respectively. A higher expression of mucin-2 protein was found in the colon compared to the ileum. In contrast, the α-defensins-1 and -4 were expressed almost exclusively in the ileum. The protein expression of the tight junction molecules claudin-1, occludin and zonula occludens-1 did not differ between colon and ileum, although some differences occurred at the mRNA level. No age- or gender-related differences were found. Differences between C57BL/6J and BALB/cJ mice were found for α-defensin-1 and -4 mRNA expression, and for urine and plasma marker concentrations. The α-defensin-1 mRNA correlated with claudin-5 mRNA, whereas α-defensin-4 mRNA correlated with claudin-3 concentrations in urine. In conclusion, we identified a number of murine intestinal barrier markers requiring tissue analyses or measurable in urine or plasma. We provide normal values for these markers in mice of different genetic background. Such data might be helpful for future animal studies in which the intestinal barrier is of interest. PMID:27583194

  14. T-TY Tank Farm Interim Surface Barrier Demonstration - Vadose Zone Monitoring FY10 Report

    SciTech Connect

    Zhang, Z. F.; Strickland, Christopher E.; Field, Jim G.; Parker, Danny L.

    2011-01-01

    The U.S. Department of Energy’s Office of River Protection has constructed interim surface barriers over a portion of the T and TY tank farms as part of the Interim Surface Barrier Demonstration Project. The interim surface barriers (hereafter referred to as the surface barriers or barriers) are designed to minimize the infiltration of precipitation into the soil zones containing radioactive contaminants and minimize the movement of the contaminants. As part of the demonstration effort, vadose zone moisture is being monitored to assess the effectiveness of the barriers at reducing soil moisture. Solar-powered systems were installed to continuously monitor soil water conditions at four locations in the T (i.e., instrument Nests TA, TB, TC, and TD) and the TY (i.e., instrument Nests TYA and TYB) Farms beneath the barriers and outside the barrier footprint as well as site meteorological conditions. Nests TA and TYA are placed in the area outside the barrier footprint and serve as controls, providing subsurface conditions outside the influence of the surface barriers. Nest TB provides subsurface measurements to assess surface-barrier edge effects. Nests TC, TD, and TYB are used to assess changes in soil-moisture conditions beneath the interim surface barriers.

  15. Development of Thermal Barrier Coating System with Superior Thermal Cyclic Properties with an Intermediate Layer Containing MoSi2

    NASA Astrophysics Data System (ADS)

    Sonoya, Keiji; Tobe, Shogo

    The authors have developed a method of improving the thermal cyclic resistance of the thermal barrier coating system that is deposited on gas turbine components. A conventional thermal barrier coating consists of a duplex system: a top coating and a bond coating. The developed system has a protective intermediate layer of MoSi2 which prevents oxidation of the bond coating. The conventional duplex plasma -sprayed coating was delaminated after 20 thermal cycles. On the other hand, the developed triple-layered coating system was not delaminated after 60 cycles. The reason for the enhanced resistance to thermal cycles of the developed triple-layered coating system is that the MoSi2 layer between the top coating and the bond coating has a self-repairing property. MoSi2 oxidizes to form SiO2, which seals the cracks and pores formed between the top coating and the bond coating. Thus, the formation of a thermally grown oxide(TGO), which causes the delamination of the coating, is prevented and the thermal cyclic resistance is improved.

  16. Assessment as a Barrier in Developing Design Expertise: Interior Design Student Perceptions of Meanings and Sources of Grades

    ERIC Educational Resources Information Center

    Smith, Kennon M.

    2013-01-01

    This article reports on a portion of a larger qualitative study focused on a group of interior design students' perceptions of their educational experiences. Twelve interior design students enrolled in their final studio course participated in interviews intended to elicit their perceptions of key barriers encountered during their…

  17. An Assessment of Readiness and Barriers towards ICT Programme Implementation: Perceptions of Agricultural Extension Officers in Indonesia

    ERIC Educational Resources Information Center

    Purnomo, Sutrisno Hadi; Lee, Yi-Hsuan

    2010-01-01

    This study investigates agricultural extension officers' perception of readiness and barriers towards implementation of ICT programme. Data were gathered from 312 extension officers affiliated with public organisations of the Ministry of Agriculture in four regencies of Indonesia. Descriptive statistics, exploratory and confirmatory factor…

  18. Second Life in Higher Education: Assessing the Potential for and the Barriers to Deploying Virtual Worlds in Learning and Teaching

    ERIC Educational Resources Information Center

    Warburton, Steven

    2009-01-01

    "Second Life" (SL) is currently the most mature and popular multi-user virtual world platform being used in education. Through an in-depth examination of SL, this article explores its potential and the barriers that multi-user virtual environments present to educators wanting to use immersive 3-D spaces in their teaching. The context is set by…

  19. Fifteen-year Assessment of a Permeable Reactive Barrier for Treatment of Chromate and Trichloroethylene in Groundwater

    EPA Science Inventory

    The fifteen-year performance of a granular iron, permeable reactive barrier (PRB; Elizabeth City, North Carolina) is reviewed with respect to contaminant treatment (hexavalent chromium and trichloroethylene) and hydraulic performance. Due to in-situ treatment of the chromium sou...

  20. Results of an Assessment to Identify Potential Barriers to Sustainable Agriculture on American Indian Reservations in the Western United States

    ERIC Educational Resources Information Center

    Singletary, Loretta; Emm, Staci; Brummer, Fara Ann; Hill, George C.; Lewis, Steve; Hebb, Vicki

    2016-01-01

    Purpose: This paper reports the results of survey research conducted with tribal producers between 2011 and 2012 on 19 of the largest American Indian reservations in Idaho, Nevada, North Dakota, Oregon, South Dakota, and Washington. The purpose of the research was to identify potential barriers to sustainable agriculture on reservation lands. This…