Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2003-01-01

The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

Calcium-magnesium Aluminosilicate (CMAS) Interactions with Advanced Environmental Barrier Coating Material

NASA Technical Reports Server (NTRS)

Wiesner, Valerie L.; Bansal, Narottam P.

2015-01-01

Particulates, like sand and volcanic ash, threaten the development of robust environmental barrier coatings (EBCs) that protect next-generation silicon-based ceramic matrix composite (CMC) turbine engine components from harsh combustion environments during service. The siliceous particulates transform into molten glassy deposits of calcium-magnesium aluminosilicate (CMAS) when ingested by an aircraft engine operating at temperatures above 1200C. In this study, a sample of desert sand was melted into CMAS glass to evaluate high-temperature interactions between the sand glass and an advanced EBC material. Desert sand glass was added to the surface of hot-pressed EBC substrates, which were then heated in air at temperatures ranging from 1200C to 1500C. Scanning electron microscopy and X-ray energy-dispersive spectroscopy were used to evaluate microstructure and phase compositions of specimens and the CMASEBC interface after heat treatments.

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

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

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

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

Calcium-Magnesium-Aluminosilicate (CMAS) Reactions and Degradation Mechanisms of Advanced Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Ahlborg, Nadia L.; Zhu, Dongming

2013-01-01

The thermochemical reactions between calcium-magnesium-aluminosilicate- (CMAS-) based road sand and several advanced turbine engine environmental barrier coating (EBC) materials were studied. The phase stability, reaction kinetics and degradation mechanisms of rare earth (RE)-silicates Yb2SiO5, Y2Si2O7, and RE-oxide doped HfO2 and ZrO2 under the CMAS infiltration condition at 1500 C were investigated, and the microstructure and phase characteristics of CMAS-EBC specimens were examined using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Experimental results showed that the CMAS dissolved RE-silicates to form crystalline, highly non-stoichiometric apatite phases, and in particular attacking the silicate grain boundaries. Cross-section images show that the CMAS reacted with specimens and deeply penetrated into the EBC grain boundaries and formed extensive low-melting eutectic phases, causing grain boundary recession with increasing testing time in the silicate materials. The preliminary results also showed that CMAS reactions also formed low melting grain boundary phases in the higher concentration RE-oxide doped HfO2 systems. The effect of the test temperature on CMAS reactions of the EBC materials will also be discussed. The faster diffusion exhibited by apatite and RE-doped oxide phases and the formation of extensive grain boundary low-melting phases may limit the CMAS resistance of some of the environmental barrier coatings at high temperatures.

Advanced Environmental Barrier Coatings Developed for SiC/SiC Composite Vanes

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis S.; Eldridge, Jeffrey I.; Zhu, Dongming; Bansal, Narottam P.; Miller, Robert A.

2003-01-01

Ceramic components exhibit superior high-temperature strength and durability over conventional component materials in use today, signifying the potential to revolutionize gas turbine engine component technology. Silicon-carbide fiber-reinforced silicon carbide ceramic matrix composites (SiC/SiC CMCs) are prime candidates for the ceramic hotsection components of next-generation gas turbine engines. A key barrier to the realization of SiC/SiC CMC hot-section components is the environmental degradation of SiC/SiC CMCs in combustion environments. This is in the form of surface recession due to the volatilization of silica scale by water vapor. An external environmental barrier coating (EBC) is a logical approach to achieve protection and long-term durability.

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

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

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

NASA Technical Reports Server (NTRS)

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

2014-01-01

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

Thermal Conductivity of Advanced Ceramic Thermal Barrier Coatings Determined by a Steady-state Laser Heat-flux Approach

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

The development of low conductivity and high temperature capable thermal barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity under future high-performance and low-emission engine heat-flux conditions. In this paper, a unique steady-state CO2 laser (wavelength 10.6 microns) heat-flux approach is described for determining the thermal conductivity and conductivity deduced cyclic durability of ceramic thermal and environmental barrier coating systems at very high temperatures (up to 1700 C) under large thermal gradients. The thermal conductivity behavior of advanced thermal and environmental barrier coatings for metallic and Si-based ceramic matrix composite (CMC) component applications has also been investigated using the laser conductivity approach. The relationships between the lattice and radiation conductivities as a function of heat flux and thermal gradient at high temperatures have been examined for the ceramic coating systems. The steady-state laser heat-flux conductivity approach has been demonstrated as a viable means for the development and life prediction of advanced thermal barrier coatings for future turbine engine applications.

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.

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

NASA Technical Reports Server (NTRS)

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

2009-01-01

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

Thermal Cyclic Behavior of Thermal and Environmental Barrier Coatings Investigated Under High-Heat-Flux Conditions

NASA Technical Reports Server (NTRS)

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

2002-01-01

Environmental barrier coatings (EBC's) have been developed to protect silicon-carbide- (SiC) based ceramic components in gas turbine engines from high-temperature environmental attack. With continuously increasing demands for significantly higher engine operating temperature, future EBC systems must be designed for both thermal and environmental protection of the engine components in combustion gases. In particular, the thermal barrier functions of EBC's become a necessity for reducing the engine-component thermal loads and chemical reaction rates, thus maintaining the required mechanical properties and durability of these components. Advances in the development of thermal and environmental barrier coatings (TBC's and EBC's, respectively) will directly impact the successful use of ceramic components in advanced engines. To develop high-performance coating systems, researchers must establish advanced test approaches. In this study, a laser high-heat-flux technique was employed to investigate the thermal cyclic behavior of TBC's and EBC's on SiC-reinforced SiC ceramic matrix composite substrates (SiC/SiC) under high thermal gradient and thermal cycling conditions. Because the laser heat flux test approach can monitor the coating's real-time thermal conductivity variations at high temperature, the coating thermal insulation performance, sintering, and delamination can all be obtained during thermal cycling tests. Plasma-sprayed yttria-stabilized zirconia (ZrO2-8 wt% Y2O3) thermal barrier and barium strontium aluminosilicate-based environmental barrier coatings (BSAS/BSAS+mullite/Si) on SiC/SiC ceramic matrix composites were investigated in this study. These coatings were laser tested in air under thermal gradients (the surface and interface temperatures were approximately 1482 and 1300 C, respectively). Some coating specimens were also subject to alternating furnace cycling (in a 90-percent water vapor environment at 1300 C) and laser thermal gradient cycling tests

Evaluation of Erosion Resistance of Advanced Turbine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

Dos Hermanas Chicanas: Overcoming Barriers to Professional Advancement

ERIC Educational Resources Information Center

Prospero, Moises

2007-01-01

Women and ethnic minorities face steep barriers to professional advancement, and those who rise to the executive level typically use a variety of strategies to overcome obstacles in their way. This study first reviewed the literature on barriers to professional advancement for women and ethnic minorities and the strategies that they report using…

Environmental Stability and Oxidation Behavior of HfO2-Si and YbGd(O) Based Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Farmer, Serene; McCue, Terry R.; Harder, Bryan; Hurst, Janet B.

2017-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, environmental durable environmental barrier coating systems. In this paper, the durability and performance of advanced Electron Beam-Physical Vapor Deposition (EB-PVD) NASA HfO2-Si and YbGdSi(O) EBC bond coat top coat systems for SiCSiC CMC have been summarized. The high temperature thermomechanical creep, fatigue and oxidation resistance have been investigated in the laboratory simulated high-heat-flux environmental test conditions. The advanced NASA EBC systems showed promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

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.

Environmental Barrier Coating Fracture, Fatigue and High-Heat-Flux Durability Modeling and Stochastic Progressive Damage Simulation

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Nemeth, Noel N.

2017-01-01

Advanced environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect emerging light-weight SiC/SiC ceramic matrix composite (CMC) engine components, further raising engine operating temperatures and performance. Because the environmental barrier coating systems are critical to the performance, reliability and durability of these hot-section ceramic engine components, a prime-reliant coating system along with established life design methodology are required for the hot-section ceramic component insertion into engine service. In this paper, we have first summarized some observations of high temperature, high-heat-flux environmental degradation and failure mechanisms of environmental barrier coating systems in laboratory simulated engine environment tests. In particular, the coating surface cracking morphologies and associated subsequent delamination mechanisms under the engine level high-heat-flux, combustion steam, and mechanical creep and fatigue loading conditions will be discussed. The EBC compostion and archtechture improvements based on advanced high heat flux environmental testing, and the modeling advances based on the integrated Finite Element Analysis Micromechanics Analysis Code/Ceramics Analysis and Reliability Evaluation of Structures (FEAMAC/CARES) program will also be highlighted. The stochastic progressive damage simulation successfully predicts mud flat damage pattern in EBCs on coated 3-D specimens, and a 2-D model of through-the-thickness cross-section. A 2-parameter Weibull distribution was assumed in characterizing the coating layer stochastic strength response and the formation of damage was therefore modeled. The damage initiation and coalescence into progressively smaller mudflat crack cells was demonstrated. A coating life prediction framework may be realized by examining the surface crack initiation and delamination propagation in conjunction with environmental

Property Evaluation and Damage Evolution of Environmental Barrier Coatings and Environmental Barrier Coated SiC/SiC Ceramic Matrix Composite Sub-Elements

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Halbig, Michael; Jaskowiak, Martha; Hurst, Janet; Bhatt, Ram; Fox, Dennis S.

2014-01-01

This paper describes recent development of environmental barrier coatings on SiC/SiC ceramic matrix composites. The creep and fatigue behavior at aggressive long-term high temperature conditions have been evaluated and highlighted. Thermal conductivity and high thermal gradient cyclic durability of environmental barrier coatings have been evaluated. The damage accumulation and complex stress-strain behavior environmental barrier coatings on SiCSiC ceramic matrix composite turbine airfoil subelements during the thermal cyclic and fatigue testing of have been also reported.

Thermal barrier coatings issues in advanced land-based gas turbines

NASA Technical Reports Server (NTRS)

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

1995-01-01

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

High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.

2007-01-01

Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.

Development of Advanced Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Miller, Robert A.

2004-01-01

Advanced multi-component, low conductivity oxide thermal barrier coatings have been developed using an approach that emphasizes real-time monitoring of thermal conductivity under conditions that are engine-like in terms of temperatures and heat fluxes. This is in contrast to the traditional approach where coatings are initially optimized in terms of furnace and burner rig durability with subsequent measurement in the as-processed or furnace-sintered condition. The present work establishes a laser high-heat-flux test as the basis for evaluating advanced plasma-sprayed and electron beam-physical vapor deposited (EB-PVD) thermal barrier coatings under the NASA Ultra-Efficient Engine Technology (UEET) Program. The candidate coating materials for this program are novel thermal barrier coatings that are found to have significantly reduced thermal conductivities and improved thermal stability due to an oxide-defect-cluster design. Critical issues for designing advanced low conductivity coatings with improved coating durability are also discussed.

Environmental barriers in mainstream schools.

PubMed

Hemmingsson, H; Borell, L

2002-01-01

Research on students with disabilities in mainstream schools often focuses on the students' personal abilities rather than on the establishment itself. To promote inclusive education, the environmental prerequisite for participation has to be explored also. The aim of this study was to identify the barriers to participation in Swedish mainstream schools, from the personal perspective of students with physical disabilities. The study also investigated how gender, diagnosis, level of mobility, academic years and availability of an assistant were related to student-environment fit. A total of 34 students with physical disabilities, aged between 10 and 19 years, participated in the study. The students were assessed by 'The school-setting interview'. Results show that two-thirds of the students experienced barriers to participation in both the physical and the social environment. A majority of the barriers originated from the way in which school activities were organized and carried out in schools. Failure to provide adequate environmental adjustments resulted in restricted participation or exclusion from some of the activities in class. Older students experienced significantly more barriers than younger ones because the school organization was less favourable. The results suggest that the way in which activities are organized in school is the area in need of most improvements to promote participation of students with physical disabilities.

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.

Distributed electrochemical sensors: recent advances and barriers to market adoption.

PubMed

Hoekstra, Rafael; Blondeau, Pascal; Andrade, Francisco J

2018-07-01

Despite predictions of their widespread application in healthcare and environmental monitoring, electrochemical sensors are yet to be distributed at scale, instead remaining largely confined to R&D labs. This contrasts sharply with the situation for physical sensors, which are now ubiquitous and seamlessly embedded in the mature ecosystem provided by electronics and connectivity protocols. Although chemical sensors could be integrated into the same ecosystem, there are fundamental issues with these sensors in the three key areas of analytical performance, usability, and affordability. Nevertheless, advances are being made in each of these fields, leading to hope that the deployment of automated and user-friendly low-cost electrochemical sensors is on the horizon. Here, we present a brief survey of key challenges and advances in the development of distributed electrochemical sensors for liquid samples, geared towards applications in healthcare and wellbeing, environmental monitoring, and homeland security. As will be seen, in many cases the analytical performance of the sensor is acceptable; it is usability that is the major barrier to commercial viability at this moment. Were this to be overcome, the issue of affordability could be addressed. Graphical Abstract ᅟ.

Phase Stability and Thermal Conductivity of Composite Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Benkel, Samantha; Zhu, Dongming

2011-01-01

Advanced environmental barrier coatings are being developed to protect SiC/SiC ceramic matrix composites in harsh combustion environments. The current coating development emphasis has been placed on the significantly improved cyclic durability and combustion environment stability in high-heat-flux and high velocity gas turbine engine environments. Environmental barrier coating systems based on hafnia (HfO2) and ytterbium silicate, HfO2-Si nano-composite bond coat systems have been processed and their stability and thermal conductivity behavior have been evaluated in simulated turbine environments. The incorporation of Silicon Carbide Nanotubes (SiCNT) into high stability (HfO2) and/or HfO2-silicon composite bond coats, along with ZrO2, HfO2 and rare earth silicate composite top coat systems, showed promise as excellent environmental barriers to protect the SiC/SiC ceramic matrix composites.

Graphene-Based Environmental Barriers

PubMed Central

Guo, Fei; Silverberg, Gregory; Bowers, Shin; Kim, Sang-Pil; Datta, Dibakar; Shenoy, Vivek; Hurt, Robert H.

2012-01-01

Many environmental technologies rely on containment by engineered barriers that inhibit the release or transport of toxicants. Graphene is a new, atomically thin, two-dimensional sheet material, whose aspect ratio, chemical resistance, flexibility, and impermeability make it a promising candidate for inclusion in a next generation of engineered barriers. Here we show that ultrathin graphene oxide (GO) films can serve as effective barriers for both liquid and vapor permeants. First, GO deposition on porous substrates is shown to block convective flow at much lower mass loadings than other carbon nanomaterials, and can achieve hydraulic conductivities of 5×10−12 cm/s or lower. Second we show that ultrathin GO films of only 20 nm thickness coated on polyethylene films reduce their vapor permeability by 90% using elemental mercury as a model vapor toxicant. The barrier performance of GO in this thin-film configuration is much better than the Nielsen model limit, which describes ideal behavior of flake-like fillers uniformly imbedded in a polymer. The Hg barrier performance of GO films is found to be sensitive to residual water in the films, which is consistent with molecular dynamics (MD) simulations that show lateral diffusion of Hg atoms in graphene interlayer spaces that have been expanded by hydration. PMID:22717015

Environmental barriers and social participation in individuals with spinal cord injury.

PubMed

Tsai, I-Hsuan; Graves, Daniel E; Chan, Wenyaw; Darkoh, Charles; Lee, Meei-Shyuan; Pompeii, Lisa A

2017-02-01

The study aimed to examine the relationship between environmental barriers and social participation among individuals with spinal cord injury (SCI). Individuals admitted to regional centers of the Model Spinal Cord Injury System in the United States due to traumatic SCI were interviewed and included in the National Spinal Cord Injury Database. This cross-sectional study applied a secondary analysis with a mixed effect model on the data from 3,162 individuals who received interviews from 2000 through 2005. Five dimensions of environmental barriers were estimated using the short form of the Craig Hospital Inventory of Environmental Factors-Short Form (CHIEF-SF). Social participation was measured with the short form of the Craig Handicap Assessment and Reporting Technique-Short Form (CHART-SF) and their employment status. Subscales of environmental barriers were negatively associated with the social participation measures. Each 1 point increase in CHIEF-SF total score (indicated greater environmental barriers) was associated with a 0.82 point reduction in CHART-SF total score (95% CI: -1.07, -0.57) (decreased social participation) and 4% reduction in the odds of being employed. Among the 5 CHIEF-SF dimensions, assistance barriers exhibited the strongest negative association with CHART-SF social participation score when compared to other dimensions, while work/school dimension demonstrated the weakest association with CHART-SF. Environmental barriers are negatively associated with social participation in the SCI population. Working toward eliminating environmental barriers, especially assistance/service barriers, may help enhance social participation for people with SCI. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Environmental Barriers and Social Participation in Individuals With Spinal Cord Injury

PubMed Central

Tsai, I-Hsuan; Graves, Daniel E.; Chan, Wenyaw; Darkoh, Charles; Lee, Meei-Shyuan; Pompeii, Lisa A.

2018-01-01

Objective The study aimed to examine the relationship between environmental barriers and social participation among individuals with spinal cord injury (SCI). Method Individuals admitted to regional centers of the Model Spinal Cord Injury System in the United States due to traumatic SCI were interviewed and included in the National Spinal Cord Injury Database. This cross-sectional study applied a secondary analysis with a mixed effect model on the data from 3,162 individuals who received interviews from 2000 through 2005. Five dimensions of environmental barriers were estimated using the short form of the Craig Hospital Inventory of Environmental Factors—Short Form (CHIEF-SF). Social participation was measured with the short form of the Craig Handicap Assessment and Reporting Technique—Short Form (CHART-SF) and their employment status. Results Subscales of environmental barriers were negatively associated with the social participation measures. Each 1 point increase in CHIEF-SF total score (indicated greater environmental barriers) was associated with a 0.82 point reduction in CHART-SF total score (95% CI: −1.07, −0.57) (decreased social participation) and 4% reduction in the odds of being employed. Among the 5 CHIEF-SF dimensions, assistance barriers exhibited the strongest negative association with CHART-SF social participation score when compared to other dimensions, while work/school dimension demonstrated the weakest association with CHART-SF. Conclusions Environmental barriers are negatively associated with social participation in the SCI population. Working toward eliminating environmental barriers, especially assistance/service barriers, may help enhance social participation for people with SCI. PMID:28045281

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan; Bhatt, Ramakrishna

2016-01-01

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

Thermal Conductivity and Sintering Behavior of Advanced Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2002-01-01

Advanced thermal barrier coatings, having significantly reduced long-term thermal conductivities, are being developed using an approach that emphasizes real-time monitoring of thermal conductivity under conditions that are engine-like in terms of temperatures and heat fluxes. This is in contrast to the traditional approach where coatings are initially optimized in terms of furnace and burner rig durability with subsequent measurement in the as-processed or furnace-sintered condition. The present work establishes a laser high-heat-flux test as the basis for evaluating advanced plasma-sprayed and physical vapor-deposited thermal barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) Program. The candidate coating materials for this program are novel thermal barrier coatings that are found to have significantly reduced thermal conductivities due to an oxide-defect-cluster design. Critical issues for designing advanced low conductivity coatings with improved coating durability are also discussed.

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

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

Environmental/Thermal Barrier Coatings for Ceramic Matrix Composites: Thermal Tradeoff Studies

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. M.; Brewer, David; Shah, Ashwin R.

2007-01-01

Recent interest in environmental/thermal barrier coatings (EBC/TBCs) has prompted research to develop life-prediction methodologies for the coating systems of advanced high-temperature ceramic matrix composites (CMCs). Heat-transfer analysis of EBC/TBCs for CMCs is an essential part of the effort. It helps establish the resulting thermal profile through the thickness of the CMC that is protected by the EBC/TBC system. This report documents the results of a one-dimensional analysis of an advanced high-temperature CMC system protected with an EBC/TBC system. The one-dimensional analysis was used for tradeoff studies involving parametric variation of the conductivity; the thickness of the EBC/TBCs, bond coat, and CMC substrate; and the cooling requirements. The insight gained from the results will be used to configure a viable EBC/TBC system for CMC liners that meet the desired hot surface, cold surface, and substrate temperature requirements.

Hierarchy as a barrier to advancement for women in academic medicine.

PubMed

Conrad, Peter; Carr, Phyllis; Knight, Sharon; Renfrew, Megan R; Dunn, Mary B; Pololi, Linda

2010-04-01

Research on barriers to professional advancement for women in academic medicine has not adequately considered the role of environmental factors and how the structure of organizations affects professional advancement and work experiences. This article examines the impact of the hierarchy, including both the organization's hierarchical structure and professionals' perceptions of this structure, in medical school organization on faculty members' experience and advancement in academic medicine. As part of an inductive qualitative study of faculty in five disparate U.S. medical schools, we interviewed 96 medical faculty at different career stages and in diverse specialties, using in-depth semistructured interviews, about their perceptions about and experiences in academic medicine. Data were coded and analysis was conducted in the grounded theory tradition. Our respondents saw the hierarchy of chairs, based on the indeterminate tenure of department chairs, as a central characteristic of the structure of academic medicine. Many faculty saw this hierarchy as affecting inclusion, reducing transparency in decision making, and impeding advancement. Indeterminate chair terms lessen turnover and may create a bottleneck for advancement. Both men and women faculty perceived this hierarchy, but women saw it as more consequential. The hierarchical structure of academic medicine has a significant impact on faculty work experiences, including advancement, especially for women. We suggest that medical schools consider alternative models of leadership and managerial styles, including fixed terms for chairs with a greater emphasis on inclusion. This is a structural reform that could increase opportunities for advancement especially for women in academic medicine.

Thermal Barrier Coatings for Advanced Gas Turbine and Diesel Engines

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

1999-01-01

Ceramic thermal barrier coatings (TBCS) have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, durability issues of these thermal barrier coatings under high temperature cyclic conditions are still of major concern. The coating failure depends not only on the coating, but also on the ceramic sintering/creep and bond coat oxidation under the operating conditions. Novel test approaches have been established to obtain critical thermomechanical and thermophysical properties of the coating systems under near-realistic transient and steady state temperature and stress gradients encountered in advanced engine systems. This paper presents detailed experimental and modeling results describing processes occurring in the ZrO2-Y2O3 thermal barrier coating systems, thus providing a framework for developing strategies to manage ceramic coating architecture, microstructure and properties.

Environmental barriers, person-environment fit and mortality among community-dwelling very old people.

PubMed

Rantakokko, Merja; Törmäkangas, Timo; Rantanen, Taina; Haak, Maria; Iwarsson, Susanne

2013-08-28

Environmental barriers are associated with disability-related outcomes in older people but little is known of the effect of environmental barriers on mortality. The aim of this study was to examine whether objectively measured barriers in the outdoor, entrance and indoor environments are associated with mortality among community-dwelling 80- to 89-year-old single-living people. This longitudinal study is based on a sample of 397 people who were single-living in ordinary housing in Sweden. Participants were interviewed during 2002-2003, and 393 were followed up for mortality until May 15, 2012.Environmental barriers and functional limitations were assessed with the Housing Enabler instrument, which is intended for objective assessments of Person-Environment (P-E) fit problems in housing and the immediate outdoor environment. Mortality data were gathered from the public national register. Cox regression models were used for the analyses. A total of 264 (67%) participants died during follow-up. Functional limitations increased mortality risk. Among the specific environmental barriers that generate the most P-E fit problems, lack of handrails in stairs at entrances was associated with the highest mortality risk (adjusted RR 1.55, 95% CI 1.14-2.10), whereas the total number of environmental barriers at entrances and outdoors was not associated with mortality. A higher number of environmental barriers indoors showed a slight protective effect against mortality even after adjustment for functional limitations (RR 0.98, 95% CI 0.96-1.00). Specific environmental problems may increase mortality risk among very-old single-living people. However, the association may be confounded by individuals' health status which is difficult to fully control for. Further studies are called for.

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.

Factors related to environmental barriers experienced by persons with and without disabilities in diverse African settings.

PubMed

Visagie, Surona; Eide, Arne H; Dyrstad, Karin; Mannan, Hasheem; Swartz, Leslie; Schneider, Marguerite; Mji, Gubela; Munthali, Alister; Khogali, Mustafa; van Rooy, Gert; Hem, Karl-Gerhard; MacLachlan, Malcolm

2017-01-01

This paper explores differences in experienced environmental barriers between individuals with and without disabilities and the impact of additional factors on experienced environmental barriers. Data was collected in 2011-2012 by means of a two-stage cluster sampling and comprised 400-500 households in different sites in South Africa, Sudan Malawi and Namibia. Data were collected through self-report survey questionnaires. In addition to descriptive statistics and simple statistical tests a structural equation model was developed and tested. The combined file comprised 9,307 participants. The Craig Hospital Inventory of Environmental Factors was used to assess the level of environmental barriers. Transportation, the natural environment and access to health care services created the biggest barriers. An exploratory factor analysis yielded support for a one component solution for environmental barriers. A scale was constructed by adding the items together and dividing by number of items, yielding a range from one to five with five representing the highest level of environmental barriers and one the lowest. An overall mean value of 1.51 was found. Persons with disabilities scored 1.66 and persons without disabilities 1.36 (F = 466.89, p < .001). Bivariate regression analyses revealed environmental barriers to be higher among rural respondents, increasing with age and severity of disability, and lower for those with a higher level of education and with better physical and mental health. Gender had an impact only among persons without disabilities, where women report more barriers than men. Structural equation model analysis showed that socioeconomic status was significantly and negatively associated with environmental barriers. Activity limitation is significantly associated with environmental barriers when controlling for a number of other individual characteristics. Reducing barriers for the general population would go some way to reduce the impact of these for

Environmental barriers and subjective health among people with chronic spinal cord injury: A cohort study

PubMed Central

Cao, Yue; Walker, Elizabeth A.; Krause, James S.

2015-01-01

Objective Although previous studies have found environmental barriers to be associated with social participation and life satisfaction after spinal cord injury (SCI), few studies exist reporting their effects on subjective health after SCI. Our purpose was to identify the prevalence of perceived environmental barriers and their effects on subjective health in persons with chronic SCI who completed two repeated measurements during a 5-year longitudinal study. Design This is a prospective cohort study. Environmental barriers were measured at baseline by the Craig Hospital Inventory of Environmental Factors-Short Form. Subjective health was measured at baseline and 5-year follow-up by days of physical and mental health not good. Other control variables included sex, race, age at injury, years since injury, and injury severity at baseline. Setting Data were collected at a specialty hospital and analyzed at a medical university in the Southeastern USA. Participants A total of 1635 participants completed both baseline and follow-up surveys. Results Twenty per cent of participants reported at least one policy barrier, 46% at least one physical and structural barrier, 22% at least one attitudinal and support barrier, 26% at least one barrier to services and assistance, and 13% at least one barrier at work or school. After controlling for sex, race, age at injury, years since injury, and injury severity, the physical and structural barriers, and services and assistance barriers measured at baseline significantly predicted subjective physical and mental health measured at follow-up. Conclusion Environmental barriers are prevalent among people with chronic SCI. They are important predictors for future subjective health. PMID:25329423

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

Analytical investigation of thermal barrier coatings on advanced power generation gas turbines

NASA Technical Reports Server (NTRS)

Amos, D. J.

1977-01-01

An analytical investigation of present and advanced gas turbine power generation cycles incorporating thermal barrier turbine component coatings was performed. Approximately 50 parametric points considering simple, recuperated, and combined cycles (including gasification) with gas turbine inlet temperatures from current levels through 1644K (2500 F) were evaluated. The results indicated that thermal barriers would be an attractive means to improve performance and reduce cost of electricity for these cycles. A recommended thermal barrier development program has been defined.

Combined acoustical and visual performance of noise barriers in mitigating the environmental impact of motorways.

PubMed

Jiang, Like; Kang, Jian

2016-02-01

This study investigated the overall performance of noise barriers in mitigating environmental impact of motorways, taking into consideration their effects on reducing noise and visual intrusions of moving traffic, but also potentially inducing visual impact themselves. A laboratory experiment was carried out, using computer-visualised video scenes and motorway traffic noise recordings to present experimental scenarios covering two traffic levels, two distances of receiver to road, two types of background landscape, and five barrier conditions including motorway only, motorway with tree belt, motorways with 3 m timber barrier, 5m timber barrier, and 5m transparent barrier. Responses from 30 participants of university students were gathered and perceived barrier performance analysed. The results show that noise barriers were always beneficial in mitigating environmental impact of motorways, or made no significant changes in environmental quality when the impact of motorways was low. Overall, barriers only offered similar mitigation effect as compared to tree belt, but showed some potential to be more advantageous when traffic level went high. 5m timber barrier tended to perform better than the 3m one at the distance of 300 m but not at 100 m possibly due to its negative visual effect when getting closer. The transparent barrier did not perform much differently from the timber barriers but tended to be the least effective in most scenarios. Some low positive correlations were found between aesthetic preference for barriers and environmental impact reduction by the barriers. Copyright © 2015 Elsevier B.V. All rights reserved.

Perceived and objective entrance-related environmental barriers and daily out-of-home mobility in community-dwelling older people.

PubMed

Portegijs, Erja; Rantakokko, Merja; Viljanen, Anne; Rantanen, Taina; Iwarsson, Susanne

We studied whether entrance-related environmental barriers, perceived and objectively recorded, were associated with moving out-of-home daily in older people with and without limitations in lower extremity performance. Cross-sectional analyses of the "Life-space mobility in old age" cohort including 848 community-dwelling 75-90-year-old of central Finland. Participants reported their frequency of moving out-of-home (daily vs. 0-6 times/week) and perceived entrance-related environmental barriers (yes/no). Lower extremity performance was assessed (Short Physical Performance Battery) and categorized as poorer (score 0-9) or good (score 10-12). Environmental barriers at entrances and in exterior surroundings were objectively registered (Housing Enabler screening tool) and divided into tertiles. Logistic regression analyses were adjusted for age, sex, number of chronic diseases, cognitive function, month of assessment, type of neighborhood, and years lived in the current home. At home entrances a median of 6 and in the exterior surroundings 5 environmental barriers were objectively recorded, and 20% of the participants perceived entrance-related barriers. The odds for moving out-of-home less than daily increased when participants perceived entrance-related barrier(s) or when they lived in homes with higher numbers of objectively recorded environmental barriers at entrances. Participants with limitations in lower extremity performance were more susceptible to these environmental barriers. Objectively recorded environmental barriers in the exterior surroundings did not compromise out-of-home mobility. Entrance-related environmental barriers may hinder community-dwelling older people to move out-of-home daily especially when their functional capacity is compromised. Potentially, reducing entrance-related barriers may help to prevent confinement to the home. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Finite Element Model Characterization Of Nano-Composite Thermal And Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Yamada, Yoshiki; Zhu, Dongming

2011-01-01

Thermal and environmental barrier coatings have been applied for protecting Si based ceramic matrix composite components from high temperature environment in advanced gas turbine engines. It has been found that the delamination and lifetime of T/EBC systems generally depend on the initiation and propagation of surface cracks induced by the axial mechanical load in addition to severe thermal loads. In order to prevent T/EBC systems from surface cracking and subsequent delamination due to mechanical and thermal stresses, T/EBC systems reinforced with nano-composite architectures have showed promise to improve mechanical properties and provide a potential crack shielding mechanism such as crack bridging. In this study, a finite element model (FEM) was established to understand the potential beneficial effects of nano-composites systems such as SiC nanotube-reinforced oxide T/EBC systems.

Managing Environmental Stress: An Evaluation of Environmental Management of the Long Point Sandy Barrier, Lake Erie, Canada.

PubMed

Kreutzwiser; Gabriel

2000-01-01

/ This paper assesses the extent to which key geomorphic components, processes, and stresses have been reflected in the management of a coastal sandy barrier environment. The management policies and practices of selected agencies responsible for Long Point, a World Biosphere Reserve along Lake Erie, Canada, were evaluated for consistency with these principles of environmental management for sandy barriers: maintaining natural stresses essential to sandy barrier development and maintenance;protecting sediment sources, transfers, and storage; recognizing spatial variability and cyclicity of natural stresses, such as barrier overwash events; and accepting and planning for long-term evolutionary changes in the sandy barrier environment. Generally, management policies and practices have not respected the dynamic and sensitive environment of Long Point because of limited mandates of the agencies involved, inconsistent policies, and failure to apply or enforce existing policies. This is particularly evident with local municipalities and less so for the Canadian Wildlife Service, the federal agency responsible for managing National Wildlife Areas at the point. In the developed areas of Long Point, landward sediment transfers and sediment storage in dunes have been impacted by cottage development, shore protection, and maintenance of roads and parking lots. Additionally, agencies responsible for managing Long Point have no jurisdiction over sediment sources as far as 95 km away. Evolutionary change of sandy barriers poses the greatest challenge to environmental managers.

Asking the Participants: Students' Views on Their Environmental Attitudes, Behaviours, Motivators and Barriers

ERIC Educational Resources Information Center

Prabawa-Sear, Kelsie; Baudains, Catherine

2011-01-01

This study investigated student views on the relationship between their environmental attitudes and behaviours and their thoughts about barriers and motivators to environmentally responsible behaviours. The environmental attitudes and behaviours of students participating in a classroom-based environmental education program were measured using two…

Investigation of novel acoustic barrier concepts phase I: concept development and preliminary evaluation

DOT National Transportation Integrated Search

2003-06-01

In a previous research project [SQDH 2002-3; "Study of the Performance of Acoustic Barriers for Indiana Toll Roads,"] the influence of : environmental factors and of advanced sound barrier concepts was investigated. The presence of temperature gradie...

Development and Performance Evaluations of HfO2-Si and Rare Earth-Si Based Environmental Barrier Bond Coat Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2014-01-01

Ceramic environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiCSiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si based EBC bond coat systems for SiCSiC CMC combustor and turbine airfoil applications are investigated. The coating design approach and stability requirements are specifically emphasized, with the development and implementation focusing on Plasma Sprayed (PS) and Electron Beam-Physic Vapor Deposited (EB-PVD) coating systems and the composition optimizations. High temperature properties of the HfO2-Si based bond coat systems, including the strength, fracture toughness, creep resistance, and oxidation resistance were evaluated in the temperature range of 1200 to 1500 C. Thermal gradient heat flux low cycle fatigue and furnace cyclic oxidation durability tests were also performed at temperatures up to 1500 C. The coating strength improvements, degradation and failure modes of the environmental barrier coating bond coat systems on SiCSiC CMCs tested in simulated stress-environment interactions are briefly discussed and supported by modeling. The performance enhancements of the HfO2-Si bond coat systems with rare earth element dopants and rare earth-silicon based bond coats are also highlighted. The advanced bond coat systems, when

Environmental barriers and supports to everyday participation: a qualitative insider perspective from people with disabilities.

PubMed

Hammel, Joy; Magasi, Susan; Heinemann, Allen; Gray, David B; Stark, Susan; Kisala, Pamela; Carlozzi, Noelle E; Tulsky, David; Garcia, Sofia F; Hahn, Elizabeth A

2015-04-01

To describe environmental factors that influence participation of people with disabilities. Constant comparative, qualitative analyses of transcripts from 36 focus groups across 5 research projects. Home, community, work, and social participation settings. Community-dwelling people (N=201) with diverse disabilities (primarily spinal cord injury, traumatic brain injury, and stroke) from 8 states. None. Environmental barriers and supports to participation. We developed a conceptual framework to describe how environmental factors influence the participation of people with disabilities, highlighting 8 domains of environmental facilitators and barriers (built, natural, assistive technology, transportation, information and technology access, social support and attitudes, systems and policies, economics) and a transactional model showing the influence of environmental factors on participation at the micro (individual), mesa (community), and macro (societal) levels. Focus group data validated some International Classification of Functioning, Disability and Health environmental categories while also bringing unique factors (eg, information and technology access, economic quality of life) to the fore. Data were used to construct items to enable people with disabilities to assess the impact of environmental factors on everyday participation from their firsthand experience. Participants with disabilities voiced the need to evaluate the impact of the environment on their participation at the immediate, community, and societal levels. The results have implications for assessing environmental facilitators and barriers to participation within rehabilitation and community settings, evaluating outcomes of environmental interventions, and effecting system and policy changes to target environmental barriers that may result in societal participation disparities versus opportunities. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights

Delamination Mechanisms of Thermal and Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Lee, Kang N.; Miller, Robert A.

1990-01-01

Advanced ceramic thermal barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability issue remains a major concern with the ever-increasing temperature requirements. In this paper, thermal cyclic response and delamination failure modes of a ZrO2-8wt%Y2O3 and mullite/BSAS thermal/environmental barrier coating system on SiC/SiC ceramic matrix composites were investigated using a laser high-heat-flux technique. The coating degradation and delamination processes were monitored in real time by measuring coating apparent conductivity changes during the cyclic tests under realistic engine temperature and stress gradients, utilizing the fact that delamination cracking causes an apparent decrease in the measured thermal conductivity. The ceramic coating crack initiation and propagation driving forces under the cyclic thermal loads, in conjunction with the mechanical testing results, will be discussed.

RESEARCH: Conceptualizing Environmental Stress: A Stress-Response Model of Coastal Sandy Barriers.

PubMed

Gabriel; Kreutzwiser

2000-01-01

/ The purpose of this paper is to develop and apply a conceptual framework of environmental stress-response for a geomorphic system. Constructs and methods generated from the literature were applied in the development of an integrative stress-response framework using existing environmental assessment techniques: interaction matrices and a systems diagram. Emphasis is on the interaction between environmental stress and the geomorphic environment of a sandy barrier system. The model illustrates a number of stress concepts pertinent to modeling environmental stress-response, including those related to stress-dependency, frequency-recovery relationships, environmental heterogeneity, spatial hierarchies and linkages, and temporal change. Sandy barrier stress-response and recovery are greatly impacted by fluctuating water levels, stress intensity and frequency, as well as environmental gradients such as differences in sediment storage and supply. Aspects of these stress-response variables are articulated in terms of three main challenges to management: dynamic stability, spatial integrity, and temporal variability. These in turn form the framework for evaluative principles that may be applied to assess how policies and management practices reflect key biophysical processes and human stresses identified by the model.

Perceptions of Challenges and Barriers to Career Advancement by Women Administrators in the University of North Carolina System

ERIC Educational Resources Information Center

Blue, Katina Michelle

2014-01-01

While women have made significant inroads and gains in the twentieth century, there remain challenges and barriers in regard to their satisfaction with career advancement opportunities. This mixed-method research study investigated perceptions of challenges and barriers to career advancement by women administrators at Group 2 institutions in the…

Advanced Low Conductivity Thermal Barrier Coatings: Performance and Future Directions (Invited paper)

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2008-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and performance will be emphasized. Advanced thermal barrier coatings have been developed using a multi-component defect clustering approach, and shown to have improved thermal stability and lower conductivity. The coating systems have been demonstrated for high temperature combustor applications. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the toughened thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion, impact and high heat-flux damage mechanisms of the thermal barrier coatings will also be described.

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

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Development and Property Evaluation of Selected HfO2-Silicon and Rare Earth-Silicon Based Bond Coats and Environmental Barrier Coating Systems for SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2016-01-01

Ceramic environmental barrier coatings (EBC) and SiC/SiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft propulsion systems because of their ability to significantly increase engine operating temperatures, improve component durability, reduce engine weight and cooling requirements. Advanced EBC systems for SiC/SiC CMC turbine and combustor hot section components are currently being developed to meet future turbine engine emission and performance goals. One of the significant material development challenges for the high temperature CMC components is to develop prime-reliant, high strength and high temperature capable environmental barrier coating bond coat systems, since the current silicon bond coat cannot meet the advanced EBC-CMC temperature and stability requirements. In this paper, advanced NASA HfO2-Si and rare earth Si based EBC bond coat EBC systems for SiC/SiC CMC combustor and turbine airfoil applications are investigated. High temperature properties of the advanced EBC systems, including the strength, fracture toughness, creep and oxidation resistance have been studied and summarized. The advanced NASA EBC systems showed some promise to achieve 1500C temperature capability, helping enable next generation turbine engines with significantly improved engine component temperature capability and durability.

Development Status and Performance Comparisons of Environmental Barrier Coating Systems for SiCSiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Harder, Bryan

2016-01-01

Environmental barrier coatings (EBC) and SiCSiC ceramic matrix composites (CMCs) will play a crucial role in future aircraft turbine engine systems, because of their ability to significantly increase engine operating temperatures, reduce engine weight and cooling requirements. This paper presents current NASA EBC-CMC development emphases including: the coating composition and processing improvements, laser high heat flux-thermal gradient thermo-mechanical fatigue - environmental testing methodology development, and property evaluations for next generation EBC-CMC systems. EBCs processed with various deposition techniques including Plasma Spray, Electron Beam - Physical Vapor Deposition, and Plasma Spray Physical Vapor Deposition (PS-PVD) will be particularly discussed. The testing results and demonstrations of advanced EBCs-CMCs in complex simulated engine thermal gradient cyclic fatigue, oxidizing-steam and CMAS environments will help provide insights into the coating development strategies to meet long-term engine component durability goals.

Barriers and enablers to advanced practitioners' ability to enact their leadership role: A scoping review.

PubMed

Elliott, Naomi; Begley, Cecily; Sheaf, Greg; Higgins, Agnes

2016-08-01

Advanced roles such as nurse practitioner, nurse consultant and advanced nurse or midwife practitioner are increasing across the world. In most countries, clinical practice, education, leadership and research are the four components that define the advanced practitioner's role. Of these, leadership is perhaps the most important part of the role, but its study has largely been neglected. There is a risk that failure to identify and respond to barriers to enacting the advanced practitioners' leadership role will limit the extent to which they can become strategic leaders for professional development, and jeopardise the long-term sustainability of the role. To identify the barriers and enablers to advanced practitioner's ability to enact their leadership role. A search of the research literature was undertaken in electronic databases (PubMed, CINAHL, PsycINFO, ProQuest Dissertation and Theses, from inception to 4-6th June 2015), unpublished research in seventeen online research repositories and institutes, and hand search of 2 leadership journals (March/April 2010-4th June 2015). Using pre-set inclusion criteria, the 1506 titles found were screened by two authors working independently. The 140 full text reports selected were reviewed by two authors separately and 34 were included, and data extracted and cross-checked. Any disagreements were discussed by the scoping team until consensus was reached. Using content analysis, the barriers and enablers relating to leadership enactment were sorted into themes based on their common characteristics, and using a Structure-Process-Outcome conceptual framework were categorised under the four structural layers: (1) healthcare system-level, (2) organisational-level, (3) team-level, and (4) advanced practitioner-level. Thirteen barriers to, and 11 enablers of, leadership were identified. Of these a majority (n=14) were related to organisational-level factors such as mentoring, support from senior management, opportunity to

Environmental Barrier Coatings for Ceramics and Ceramic Composites

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis; Eldridge, Jeffrey; Robinson, R. Craig; Bansal, Narottam

2004-01-01

One key factor that limits the performance of current gas turbine engines is the temperature capability of hot section structural components. Silicon-based ceramics, such as SiC/SiC composites and monolithic Si3N4, are leading candidates to replace superalloy hot section components in the next generation gas turbine engines due to their excellent high temperature properties. A major stumbling block to realizing Si-based ceramic hot section components is the recession of Si-based ceramics in combustion environments due to the volatilization of silica scale by water vapor. An external environmental barrier coating (EBC) is the most promising approach to preventing the recession. Current EBCs are based on silicon, mullite (3A12O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit the durability and temperature capability of current EBCs. Research is underway to develop EBCs with longer life and enhanced temperature capability. Understanding key issues affecting the performance of current EBCs is necessary for successful development of advanced EBCs. These issues include stress, chemical compatibility, adherence, and water vapor stability. Factors that affect stress are thermal expansion mismatch, phase stability, chemical stability, elastic modulus, etc. The current understanding on these issues will be discussed.

Thermal Conductivity of Ceramic Thermal Barrier and Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

Crossing the Barriers: An Analysis of Land Access Barriers to Geothermal Development and Potential Improvement Scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levine, Aaron L; Young, Katherine R

Developers have identified many non-technical barriers to geothermal power development, including access to land. Activities required for accessing land, such as environmental review and private and public leasing can take a considerable amount of time and can delay or prevent project development. This paper discusses the impacts to available geothermal resources and deployment caused by land access challenges, including tribal and cultural resources, environmentally sensitive areas, biological resources, land ownership, federal and state lease queues, and proximity to military installations. In this analysis, we identified challenges that have the potential to prevent development of identified and undiscovered hydrothermal geothermal resources.more » We found that an estimated 400 MW of identified geothermal resource potential and 4,000 MW of undiscovered geothermal resource potential were either unallowed for development or contained one or more significant barriers that could prevent development at the site. Potential improvement scenarios that could be employed to overcome these barriers include (1) providing continuous funding to the U.S. Forest Service (USFS) for processing geothermal leases and permit applications and (2) the creation of advanced environmental mitigation measures. The model results forecast that continuous funding to the USFS could result in deployment of an additional 80 MW of geothermal capacity by 2030 and 124 MW of geothermal capacity by 2050 when compared to the business-as-usual scenario. The creation of advanced environmental mitigation measures coupled with continuous funding to the USFS could result in deployment of an additional 97 MW of geothermal capacity by 2030 and 152 MW of geothermal capacity by 2050 when compared to the business-as-usual scenario. The small impact on potential deployment in these improvement scenarios suggests that these 4,400 MW have other barriers to development in addition to land access. In other words

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

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

Relationship of perceived environmental barriers and disability in community-dwelling elderly in Taiwan – a population-based study

PubMed Central

2014-01-01

Background To identify the relationship between perceived environmental barriers and disability in community-dwelling elderly. Methods Cross-sectional study in two community service centers in Tainan. We enrolled 200 community-dwelling residents, aged above 65 years, who had resided in the same community for at least 12 months. Basic activity of daily living (BADL) and instrumental activity of daily living (IADL) were assessed using the Hierarchy of Care Required (HCR). There were 59 participants in BADL disability and 109 in IADL disability. Perceived environmental barriers were assessed using the Craig Hospital Inventory of Environmental Factors (CHIEF). We used multinomial logistic regression to examine the relationship of perceived environmental barriers and disability. Results The presence of perceived environmental barriers was related to BADL disability (OR = 4.39, 95% CI = 1.01-19.11) and IADL disability (IADL with difficulty in 1–2 tasks: OR = 9.93, 95% CI = 3.22-30.56; IADL with difficulty in more than 2 tasks: OR = 8.40, 95% CI = 1.83-38.51). The presence of physically/structurally perceived environmental barriers was related to BADL disability (OR = 4.90, 95% CI = 1.01-23.86) and IADL disability (IADL with difficulty in 1–2 tasks: OR = 4.61, 95% CI = 1.27-16.76; IADL with difficulty in more than 2 tasks: OR = 17.05, 95% CI = 2.82-103.30). Conclusions Perceived environmental barriers are related to disability in community-dwelling elderly. PMID:24885956

Physical activity behavior change in middle-aged and older women: the role of barriers and of environmental characteristics.

PubMed

Kowal, John; Fortier, Michelle Sheila

2007-06-01

The majority of North American women are insufficiently active. Using an ecological approach to examine physical activity behavior in a sample of middle-aged and older women, this study aimed to (1) describe barriers to physical activity behavior change as well as environmental characteristics present in their neighborhoods, (2) examine relationships between barriers and physical activity behavior change, and (3) investigate environmental characteristics that may contribute to physical activity behavior change. Participants were 149 women ranging in age between 39 and 68. At Time 1, self-reported physical activity was assessed. Six months later (Time 2), barriers and environmental characteristics were measured, and physical activity was re-assessed. The most prevalent barriers were daily activities and fatigue. Over time, inactive women reported higher levels of barriers (e.g. fatigue, lack of interest in physical activity) than women who remained active or increased their physical activity level. Certain environmental characteristics (e.g. enjoyable scenery, seeing others exercising in their neighborhood) are suggested as potential contributors to physical activity behavior change.

Advancing Environmental Education and Training for Sustainable Management of Environmental Resources in Palestine

ERIC Educational Resources Information Center

Al-Sa'ed, Rashed; Abu-Madi, Maher; Heun, Jetze

2009-01-01

This article describes the various capacity-building activities at the Institute of Environmental and Water Studies of Birzeit University during the past 10 years. It highlights the gained experience in advancing environmental science and engineering education and training programs as components of sustainable water and environmental management…

Mechanism for initiation of food allergy: Dependence on skin barrier mutations and environmental allergen costimulation.

PubMed

Walker, Matthew T; Green, Jeremy E; Ferrie, Ryan P; Queener, Ashley M; Kaplan, Mark H; Cook-Mills, Joan M

2018-05-01

Mechanisms for the development of food allergy in neonates are unknown but clearly linked in patient populations to a genetic predisposition to skin barrier defects. Whether skin barrier defects contribute functionally to development of food allergy is unknown. The purpose of the study was to determine whether skin barrier mutations, which are primarily heterozygous in patient populations, contribute to the development of food allergy. Mice heterozygous for the filaggrin (Flg) ft and Tmem79 ma mutations were skin sensitized with environmental and food allergens. After sensitization, mice received oral challenge with food allergen, and then inflammation, inflammatory mediators, and anaphylaxis were measured. We define development of inflammation, inflammatory mediators, and food allergen-induced anaphylaxis in neonatal mice with skin barrier mutations after brief concurrent cutaneous exposure to food and environmental allergens. Moreover, neonates of allergic mothers have increased responses to suboptimal sensitization with food allergens. Importantly, responses to food allergens by these neonatal mice were dependent on genetic defects in skin barrier function and on exposure to environmental allergens. ST2 blockade during skin sensitization inhibited the development of anaphylaxis, antigen-specific IgE, and inflammatory mediators. Neonatal anaphylactic responses and antigen-specific IgE were also inhibited by oral pre-exposure to food allergen, but interestingly, this was blunted by concurrent pre-exposure of the skin to environmental allergen. These studies uncover mechanisms for food allergy sensitization and anaphylaxis in neonatal mice that are consistent with features of human early-life exposures and genetics in patients with clinical food allergy and demonstrate that changes in barrier function drive development of anaphylaxis to food allergen. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Category mistakes: A barrier to effective environmental management.

PubMed

Wallace, Ken J; Jago, Mark

2017-09-01

How entities, the things that exist, are defined and categorised affects all aspects of environmental management including technical descriptions, quantitative analyses, participatory processes, planning, and decisions. Consequently, ambiguous definitions and wrongly assigning entities to categories, referred to as category mistakes, are barriers to effective management. Confusion caused by treating the term 'biodiversity' variously as the property of an area, the biota of an area, and a preferred end state (a value) - quite different categories of entities - is one example. To overcome such difficulties, we develop and define four entity categories - elements, processes, properties, and values - and two derived categories - states and systems. We argue that adoption of these categories and definitions will significantly improve environmental communication and analysis, and thus strengthen planning and decision-making. Copyright © 2017 Elsevier Ltd. All rights reserved.

Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

NASA Technical Reports Server (NTRS)

Lee, Kang; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

2017-01-01

SiC/SiC Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment because of their light weight, higher temperature capability, and oxidation resistance. Limitations of SiC/SiC CMCs include surface recession and component cracking and associated chemical changes in the CMC. The solutions pursued to improve the life of SiC/SiC CMCs include the incorporation of coating systems that provide surface protection, which has become known as an Environmental Barrier Coating (EBC). The development of EBCs for the protection of gas turbine hot section CMC components was a continuation of coating development work for corrosion protection of silicon-based monolithics. Work on EBC development for SiC/SiC CMCs has been ongoing at several national laboratories and the original gas turbine equipment manufacturers. The work includes extensive laboratory, rig and engine testing, including testing of EBC coated SiC/SiC CMCs in actual field applications. Another EBC degradation issue which is especially critical for CMC components used in aircraft engines is the degradation from glassy deposits of calcium-magnesium-aluminosilicate (CMAS) with other minor oxides. This paper addresses the need for and properties of external coatings on SiC/SiC CMCs to extend their useful life in service and the retention of their properties.

Barriers to advancement in academic surgery: views of senior residents and early career faculty.

PubMed

Cochran, Amalia; Elder, William B; Crandall, Marie; Brasel, Karen; Hauschild, Tricia; Neumayer, Leigh

2013-11-01

A significant faculty attrition rate exists in academic surgery. The authors hypothesized that senior residents and early-career faculty members have different perceptions of advancement barriers in academic surgery. A modified version of the Career Barriers Inventory-Revised was administered electronically to surgical residents and early-career surgical faculty members at 8 academic medical centers. Residents identified a lack of mentorship as a career barrier about half as often as faculty members. Residents were twice as likely as faculty members to view childbearing as a career barrier. Many early-career faculty members cite a lack of mentors as a limitation to their career development in academic surgery. Childbearing remains a complex perceived influence for female faculty members in particular. Female faculty members commonly perceive differential treatment and barriers on the basis of their sex. Faculty development programs should address both systemic and sex-specific obstacles if academic surgery is to remain a vibrant field. Copyright © 2013 Elsevier Inc. All rights reserved.

Thermal Residual Stress in Environmental Barrier Coated Silicon Nitride - Modeled

NASA Technical Reports Server (NTRS)

Ali, Abdul-Aziz; Bhatt, Ramakrishna T.

2009-01-01

When exposed to combustion environments containing moisture both un-reinforced and fiber reinforced silicon based ceramic materials tend to undergo surface recession. To avoid surface recession environmental barrier coating systems are required. However, due to differences in the elastic and thermal properties of the substrate and the environmental barrier coating, thermal residual stresses can be generated in the coated substrate. Depending on their magnitude and nature thermal residual stresses can have significant influence on the strength and fracture behavior of coated substrates. To determine the maximum residual stresses developed during deposition of the coatings, a finite element model (FEM) was developed. Using this model, the thermal residual stresses were predicted in silicon nitride substrates coated with three environmental coating systems namely barium strontium aluminum silicate (BSAS), rare earth mono silicate (REMS) and earth mono di-silicate (REDS). A parametric study was also conducted to determine the influence of coating layer thickness and material parameters on thermal residual stress. Results indicate that z-direction stresses in all three systems are small and negligible, but maximum in-plane stresses can be significant depending on the composition of the constituent layer and the distance from the substrate. The BSAS and REDS systems show much lower thermal residual stresses than REMS system. Parametric analysis indicates that in each system, the thermal residual stresses can be decreased with decreasing the modulus and thickness of the coating.

Current Issues with Environmental Barrier Coatings for Ceramics and Ceramic Composites

NASA Technical Reports Server (NTRS)

Lee, Kang N.

2004-01-01

The environmental barrier coating (EBC) for SiC/SiC ceramic matrix composites and Si3N4 ceramics is an emerging field as the application of silicon-based ceramics in the gas turbine engine hot section is on the horizon, both for aero and industrial gas turbines. EBC is an enabling technology for silicon-based ceramics because these materials without an EBC cannot be used in combustion environments due to rapid surface recession. Significant progress in EBC development has been made during the last decade through various government-sponsored programs. Current EBCs are based on silicon, mullite (3Al2O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit temperature capability of current EBCs to about 1350 C for long-term applications. There is a need for higher temperature EBCs as the temperature capability of silicon-based ceramics continue to increase. Therefore, research is underway to develop EBCs with improved temperature capability compared to current EBCs. The current status and issues with the advanced EBC development efforts will be discussed.

Advanced Environmental Monitoring Technologies

NASA Technical Reports Server (NTRS)

Jan, Darrell

2004-01-01

Viewgraphs on Advanced Environmental Monitoring Technologies are presented. The topics include: 1) Monitoring & Controlling the Environment; 2) Illustrative Example: Canary 3) Ground-based Commercial Technology; 4) High Capability & Low Mass/Power + Autonomy = Key to Future SpaceFlight; 5) Current Practice: in Flight; 6) Current Practice: Post Flight; 7) Miniature Mass Spectrometer for Planetary Exploration and Long Duration Human Flight; 8) Hardware and Data Acquisition System; 9) 16S rDNA Phylogenetic Tree; and 10) Preview of Porter.

Advances in environmental and occupational respiratory diseases in 2009.

PubMed

Peden, David B; Bush, Robert K

2010-03-01

The year 2009 led to a number of significant advances in environmental and occupational allergic diseases. The role of exposure to environmental pollutants, respiratory viruses, and allergen exposure showed significant advances. New allergens were identified. Occupational asthma and the relationship of complementary and alternative medicine to allergic diseases were extensively reviewed. New approaches to immunotherapy, novel vaccine techniques, and methods to reduce risks for severe allergic disease were addressed.

Broadening Extension's Capacity--Comparing Extension Agents' and Environmental Educators' Perceptions of Needs and Barriers

ERIC Educational Resources Information Center

Smaldone, Dave; Boone, Deborah A.; Selin, Steve; See, Amanda

2011-01-01

Conservation and environmental education share similar goals with Extension and thus holds partnership potential for Extension. The study reported here compared the needs and barriers faced by environmental educators and Extension agents in West Virginia using a mail survey. Results indicated there were both similarities and differences in the…

Advancing environmental health surveillance in the US through a national human biomonitoring network.

PubMed

Latshaw, Megan Weil; Degeberg, Ruhiyyih; Patel, Surili Sutaria; Rhodes, Blaine; King, Ewa; Chaudhuri, Sanwat; Nassif, Julianne

2017-03-01

The United States lacks a comprehensive, nationally-coordinated, state-based environmental health surveillance system. This lack of infrastructure leads to: • varying levels of understanding of chemical exposures at the state & local levels • often inefficient public health responses to chemical exposure emergencies (such as those that occurred in the Flint drinking water crisis, the Gold King mine spill, the Elk river spill and the Gulf Coast oil spill) • reduced ability to measure the impact of public health interventions or environmental policies • less efficient use of resources for cleaning up environmental contamination Establishing the National Biomonitoring Network serves as a step toward building a national, state-based environmental health surveillance system. The Network builds upon CDC investments in emergency preparedness and environmental public health tracking, which have created advanced chemical analysis and information sharing capabilities in the state public health systems. The short-term goal of the network is to harmonize approaches to human biomonitoring in the US, thus increasing the comparability of human biomonitoring data across states and communities. The long-term goal is to compile baseline data on exposures at the state level, similar to data found in CDC's National Report on Human Exposure to Environmental Chemicals. Barriers to success for this network include: available resources, effective risk communication strategies, data comparability & sharing, and political will. Anticipated benefits include high quality data on which to base public health and environmental decisions, data with which to assess the success of public health interventions, improved risk assessments for chemicals, and new ways to prioritize environmental health research. Copyright © 2016 Elsevier GmbH. All rights reserved.

Environmental Barrier Coatings for Ceramic Matrix Composites - An Overview

NASA Technical Reports Server (NTRS)

Lee, Kang; Zhu, Dongming; Wiesner, Valerie Lynn; van Roode, Mark; Kashyap, Tania; Zhu, Dongming; Wiesner, Valerie

2016-01-01

Ceramic Matrix Composites (CMCs) are increasingly being considered as structural materials for advanced power generation equipment. Broadly speaking the two classes of materials are oxide-based CMCs and non-oxide based CMCs. The non-oxide CMCs are primarily silicon-based. Under conditions prevalent in the gas turbine hot section the water vapor formed in the combustion of gaseous or liquid hydrocarbons reacts with the surface-SiO2 to form volatile products. Progressive surface recession of the SiC-SiC CMC component, strength loss as a result of wall thinning and chemical changes in the component occur, which leads to the loss of structural integrity and mechanical strength and becomes life limiting to the equipment in service. The solutions pursued to improve the life of SiC-SiC CMCs include the incorporation of an external barrier coating to provide surface protection to the CMC substrate. The coating system has become known as an Environmental Barrier Coating (EBC). The relevant early coatings work was focused on coatings for corrosion protection of silicon-based monolithic ceramics operating under severely corrosive conditions. The development of EBCs for gas turbine hot section components was built on the early work for silicon-based monolithics. The first generation EBC is a three-layer coating, which in its simplest configuration consists of a silicon (Si) base coat applied on top of the CMC, a barium-strontium-aluminosilicate (BSAS) surface coat resistant to water vapor attack, and a mullite-based intermediate coating layer between the Si base coat and BSAS top coat. This system can be represented as Si-Mullite-BSAS. While this baseline EBC presented a significant improvement over the uncoated SiC-SiC CMC, for the very long durations of 3-4 years or more expected for industrial operation further improvements in coating durability are desirable. Also, for very demanding applications with higher component temperatures but shorter service lives more rugged EBCs

PARTNERING WITH DOE TO APPLY ADVANCED BIOLOGICAL, ENVIRONMENTAL, AND COMPUTATIONAL SCIENCE TO ENVIRONMENTAL ISSUES

EPA Science Inventory

On February 18, 2004, the U.S. Environmental Protection Agency and Department of Energy signed a Memorandum of Understanding to expand the research collaboration of both agencies to advance biological, environmental, and computational sciences for protecting human health and the ...

Environmental Barrier Coatings for Silicon-Based Ceramics

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis S.; Robinson, Raymond C.; Bansal, Narottam P.

2001-01-01

Silicon-based ceramics, such as SiC fiber-reinforced SiC (SiC/SiC ceramic matrix composites (CMC) and monolithic silicon nitride (Si3N4), are prime candidates for hot section structural components of next generation gas turbine engines. Silicon-based ceramics, however, suffer from rapid surface recession in combustion environments due to volatilization of the silica scale via reaction with water vapor, a major product of combustion. Therefore, application of silicon-based ceramic components in the hot section of advanced gas turbine engines requires development of a reliable method to protect the ceramic from environmental attack. An external environmental barrier coating (EBC) is considered a logical approach to achieve protection and CP long-term stability. The first generation EBC consisted of two layers, mullite (3Al2O3-2SiO2) bond coat and yttria-stabilized zirconia (YSZ, ZrO2-8 Wt.% Y2O3) top coat. Second generation EBCs, with substantially improved performance compared with the first generation EBC, were developed in the NASA High Speed Research-Enabling Propulsion Materials (HSR-EPM) Program. The first generation EBC consisted of two layers, mullite (3Al2O3-2SiO2) bond coat and yttria-stabilized zirconia (YSZ, ZrO2-8 wt.% Y2O3) top coat. Second generation EBCs, with substantially improved performance compared with the first generation EBC, were developed in the NASA High Speed Research-Enabling Propulsion Materials (HSR-EPM) Program (5). They consist of three layers, a silicon first bond coat, a mullite or a mullite + BSAS (BaO(1-x)-SrO(x)-Al2O3-2SiO2) second bond coat, and a BSAS top coat. The EPM EBCs were applied on SiC/SiC CMC combustor liners in three Solar Turbines (San Diego, CA) Centaur 50s gas turbine engines. The combined operation of the three engines has accumulated over 24,000 hours without failure (approximately 1,250 C maximum combustor liner temperature), with the engine in Texaco, Bakersfield, CA, accumulating about 14,000 hours. As the

Climate change and environmentally responsible behavior on the Great Barrier Reef, Australia

Treesearch

Jee In Yoon; Gerard Kyle; Carena J. vanRiper; Stephen G. Sutton

2012-01-01

This study explored the relationship between Australians' perceptions of climate change, its impact on the Great Barrier Reef (GBR), and predictors of environmentally responsible behavior (ERB). Our hypothesized model suggested that general attitudes toward climate change, social pressure for engaging in ERBs (subjective norms), and perceived behavioral control (...

The Advanced Technology Environmental Education Center Summer Fellows Institute.

ERIC Educational Resources Information Center

Depken, Diane E.; Zeman, Catherine L.; Lensch, Ellen Kabat; Brown, Edward J.

2002-01-01

Describes the background, activities, and outcomes of the Advanced Technology Environmental Education Center (ATEEC) and its Summer Fellows Institutes as a model for disciplinary and cross-disciplinary infusion of environmental science and technology content, curriculum, and methods into the classroom. Presents experiences, themes, and activities…

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.

Twelfth International Symposium on Recent Advances in Environmental Health Research.

PubMed

Tchounwou, Paul B

2016-05-04

During the past century, environmental hazards have become a major concern, not only to public health professionals, but also to the society at large because of their tremendous health, socio-cultural and economic impacts. Various anthropogenic or natural factors have been implicated in the alteration of ecosystem integrity, as well as in the development of a wide variety of acute and/or chronic diseases in humans. It has also been demonstrated that many environmental agents, acting either independently or in combination with other toxins, may induce a wide range of adverse health outcomes. Understanding the role played by the environment in the etiology of human diseases is critical to designing cost-effective control/prevention measures. This special issue of International Journal of Environmental Research and Public Health includes the proceedings of the Twelfth International Symposium on Recent Advances in Environmental Health Research. The Symposium provided an excellent opportunity to discuss the scientific advances in biomedical, environmental, and public health research that addresses global environmental health issues.

Environmental and Mechanical Stability of Environmental Barrier Coated SA Tyrannohex SiC Composites Under Simulated Turbine Engine Environments

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Halbig, Michael Charles; Sing, Mrityunjay

2014-01-01

The environmental stability and thermal gradient cyclic durability performance of SA Tyrannohex composites were investigated for turbine engine component applications. The work has been focused on investigating the combustion rig recession, cyclic thermal stress resistance and thermomechanical low cycle fatigue of uncoated and environmental barrier coated Tyrannohex SiC SA composites in simulated turbine engine combustion water vapor, thermal gradients, and mechanical loading conditions. Flexural strength degradations have been evaluated, and the upper limits of operating temperature conditions for the SA composite material systems are discussed based on the experimental results.

Advanced Technologies and Data Management Practices in Environmental Science: Lessons from Academia

ERIC Educational Resources Information Center

Hernandez, Rebecca R.; Mayernik, Matthew S.; Murphy-Mariscal, Michelle L.; Allen, Michael F.

2012-01-01

Environmental scientists are increasing their capitalization on advancements in technology, computation, and data management. However, the extent of that capitalization is unknown. We analyzed the survey responses of 434 graduate students to evaluate the understanding and use of such advances in the environmental sciences. Two-thirds of the…

Airway Epithelial Barrier Dysfunction in Chronic Obstructive Pulmonary Disease: Role of Cigarette Smoke Exposure.

PubMed

Aghapour, Mahyar; Raee, Pourya; Moghaddam, Seyed Javad; Hiemstra, Pieter S; Heijink, Irene H

2018-02-01

The epithelial lining of the airway forms the first barrier against environmental insults, such as inhaled cigarette smoke, which is the primary risk factor for the development of chronic obstructive pulmonary disease (COPD). The barrier is formed by airway epithelial junctions, which are interconnected structures that restrict permeability to inhaled pathogens and environmental stressors. Destruction of the epithelial barrier not only exposes subepithelial layers to hazardous agents in the inspired air, but also alters the normal function of epithelial cells, which may eventually contribute to the development of COPD. Of note, disruption of epithelial junctions may lead to modulation of signaling pathways involved in differentiation, repair, and proinflammatory responses. Epithelial barrier dysfunction may be particularly relevant in COPD, where repeated injury by cigarette smoke exposure, pathogens, inflammatory mediators, and impaired epithelial regeneration may compromise the barrier function. In the current review, we discuss recent advances in understanding the mechanisms of barrier dysfunction in COPD, as well as the molecular mechanisms that underlie the impaired repair response of the injured epithelium in COPD and its inability to redifferentiate into a functionally intact epithelium.

Upper Temperature Limit of Environmental Barrier Coatings for Enabling Propulsion Materials Established

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis S.; Robinson, R. Craig

2001-01-01

Silicon-based ceramics, such as SiC/SiC composites and Si3N4, are the prime candidates for hot section structural components of next-generation gas turbines. A key barrier to such an application is the rapid recession of silicon-based ceramics in combustion environments because of the volatilization of silica scale by water vapor (refs. 1 and 2). Environmental barrier coatings (EBC's) were developed to prevent recession in the High Speed Research--Enabling Propulsion Materials (HSR-EPM) Program (refs. 3 and 4). An investigation under the Ultra-Efficient Engine Technology Program was undertaken at the NASA Glenn Research Center to establish the upper temperature limit of the EPM EBC.

Advanced aviation environmental modeling tools to inform policymakers

DOT National Transportation Integrated Search

2012-08-19

Aviation environmental models which conform to international guidance have advanced : over the past several decades. Enhancements to algorithms and databases have increasingly : shown these models to compare well with gold standard measured data. The...

Thermomechanical and Environmental Durability of Environmental Barrier Coated Ceramic Matrix Composites Under Thermal Gradients

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Bhatt, Ramakrishna T.; Harder, Bryan

2016-01-01

This paper presents the developments of thermo-mechanical testing approaches and durability performance of environmental barrier coatings (EBCs) and EBC coated SiCSiC ceramic matrix composites (CMCs). Critical testing aspects of the CMCs will be described, including state of the art instrumentations such as temperature, thermal gradient, and full field strain measurements; materials thermal conductivity evolutions and thermal stress resistance; NDE methods; thermo-mechanical stress and environment interactions associated damage accumulations. Examples are also given for testing ceramic matrix composite sub-elements and small airfoils to help better understand the critical and complex CMC and EBC properties in engine relevant testing environments.

Promoting Pro-Environmental Printing Behavior: The Role of ICT Barriers and Sustainable Values

ERIC Educational Resources Information Center

Suleri, Javed; Cavagnaro, Elena

2016-01-01

This study aims to explore how to reduce printing at elementary schools through strengthening both the effective use of ICT and pro-environmental values. Literature review is presented in themes--ICT barriers (fears, knowledge, skills and time), demographic, printing behavior and sustainable values (egoistic, hedonic, prosocial & biospheric).…

A public health perspective to environmental barriers and accessibility problems for senior citizens living in ordinary housing.

PubMed

Granbom, Marianne; Iwarsson, Susanne; Kylberg, Marianne; Pettersson, Cecilia; Slaug, Björn

2016-08-11

Housing environments that hinder performance of daily activities and impede participation in social life have negative health consequences particularly for the older segment of the population. From a public health perspective accessible housing that supports active and healthy ageing is therefore crucial. The objective of the present study was to make an inventory of environmental barriers and investigate accessibility problems in the ordinary housing stock in Sweden as related to the functional capacity of senior citizens. Particular attention was paid to differences between housing types and building periods and to identify environmental barriers generating the most accessibility problems for sub-groups of senior citizens. Data on environmental barriers in dwellings from three databases on housing and health in old age was analysed (N = 1021). Four functional profiles representing large groups of senior citizens were used in analyses of the magnitude and severity of potential accessibility problems. Differences in terms of type of housing and building period were examined. High proportions of one-family houses as well as multi-dwellings had substantial numbers of environmental barriers, with significantly lower numbers in later building periods. Accessibility problems occurred already for senior citizens with few functional limitations, but more profound for those dependent on mobility devices. The most problematic housing sections were entrances in one-family houses and kitchens of multi-dwellings. Despite a high housing standard in the Swedish ordinary housing stock the results show substantial accessibility problems for senior citizens with functional limitations. To make housing accessible large-scale and systematic efforts are required.

Barriers and strategies to an iterative model of advance care planning communication.

PubMed

Ahluwalia, Sangeeta C; Bekelman, David B; Huynh, Alexis K; Prendergast, Thomas J; Shreve, Scott; Lorenz, Karl A

2015-12-01

Early and repeated patient-provider conversations about advance care planning (ACP) are now widely recommended. We sought to characterize barriers and strategies for realizing an iterative model of ACP patient-provider communication. A total of 2 multidisciplinary focus groups and 3 semistructured interviews with 20 providers at a large Veterans Affairs medical center. Thematic analysis was employed to identify salient themes. Barriers included variation among providers in approaches to ACP, lack of useful information about patient values to guide decision making, and ineffective communication between providers across settings. Strategies included eliciting patient values rather than specific treatment choices and an increased role for primary care in the ACP process. Greater attention to connecting providers across the continuum, maximizing the potential of the electronic health record, and linking patient experiences to their values may help to connect ACP communication across the continuum. © The Author(s) 2014.

Advances in environmental and occupational disorders in 2012.

PubMed

Peden, David B; Bush, Robert K

2013-03-01

The year 2012 produced a number of advances in our understanding of the effect of environmental factors on allergic diseases, identification of new allergens, immune mechanisms in host defense, factors involved in asthma severity, and therapeutic approaches. This review focuses on the articles published in the Journal in 2012 that enhance our knowledge base of environmental and occupational disorders. Identification of novel allergens can improve diagnostics, risk factor analysis can aid preventative approaches, and studies of genetic-environmental interactions and immune mechanisms will lead to better therapeutics. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Weighing environmental advantages and disadvantages of advanced wastewater treatment of micro-pollutants using environmental life cycle assessment.

PubMed

Wenzel, H; Larsen, H F; Clauson-Kaas, J; Høibye, L; Jacobsen, B N

2008-01-01

Much research and development effort is directed towards advances in municipal wastewater treatment aiming at reducing the effluent content of micro-pollutants and pathogens. The objective is to further reduce the eco-toxicity, hormone effects and pathogenic effects of the effluent. Such further polishing of the effluent, however, involves an environmental trade-off: the reduction in eco-toxicity, hormone effects, etc. will happen at the expense of increased resource- and energy consumption. Obviously, at some point of further advances, there must be an 'environmental break-even'. This trade-off was investigated using Life Cycle Assessment (LCA) methodology and based on a literature review of advanced treatment performance. The LCA evaluation comprised sand filtration, ozonation and MBRs and assessed the effect of extending existing tertiary treatment with these technologies on a variety of micro-pollutants being: heavy metals (Cd, Pb, Ni), endocrine disruptors (E2 and EE2), PAH, DEHP, and detergents (LAS & NPE). It was found, in some of the studied scenarios, that more environmental impact may be induced than removed by the advanced treatment. The study showed that for the 3 technologies, sand filtration has the best balance between prevented and induced impacts, and sand filtration proved to have a net environmental benefit under the assumptions used in the study. But the outcome of the study suggests that this is not always the case for ozonation and MBR.

Advanced instrumentation concepts for environmental control subsystems

NASA Technical Reports Server (NTRS)

Yang, P. Y.; Schubert, F. H.; Gyorki, J. R.; Wynveen, R. A.

1978-01-01

Design, evaluation and demonstration of advanced instrumentation concepts for improving performance of manned spacecraft environmental control and life support systems were successfully completed. Concepts to aid maintenance following fault detection and isolation were defined. A computer-guided fault correction instruction program was developed and demonstrated in a packaged unit which also contains the operator/system interface.

Perceived environmental barriers to outdoor mobility and changes in sense of autonomy in participation outdoors among older people: a prospective two-year cohort study.

PubMed

Rantakokko, Merja; Portegijs, Erja; Viljanen, Anne; Iwarsson, Susanne; Kauppinen, Markku; Rantanen, Taina

2017-08-01

The aim was to study whether perceived environmental barriers to outdoor mobility affect changes in sense of autonomy in participation outdoors among community-dwelling older people over a two-year period. Community-dwelling people aged 75-90 years (n = 848) in central Finland were interviewed on two occasions, face-to-face at baseline and over the telephone two years later. Perceived environmental barriers to outdoor mobility were assessed using a 15-item structured questionnaire, and the sum scores categorized into tertiles (0, 1 and 2 or more barriers). Autonomy in participation outdoors was assessed with the 'Impact on Participation and Autonomy' (IPA) questionnaire using the autonomy outdoors subscale (score range 0-20, higher scores indicating more restricted autonomy). Scores for autonomy in participation outdoors were available for 848 participants at baseline (mean 6.2, SD = 3.8) and for 748 participants at the two-year follow-up (mean 6.7, SD = 3.9). At baseline, those reporting multiple environmental barriers had the most restricted autonomy, while those reporting no environmental barriers had the least restricted autonomy (p < .001). Over the follow-up, autonomy in participation outdoors declined more among those reporting multiple environmental barriers compared to those reporting none (age- and sex-adjusted group*time β = .629, s.e. = .277, p = .023). Adjustment for cognitive functioning, education, number of chronic conditions and change in walking difficulty did not influence the association. Perceived environmental barriers to outdoor mobility accelerate the decline in autonomy in participation outdoors among older community-dwelling people. Understanding factors affecting autonomy can help in finding ways to support the sense of autonomy as people age.

Creep, Fatigue and Fracture Behavior of Environmental Barrier Coating and SiC-SiC Ceramic Matrix Composite Systems: The Role of Environment Effects

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Ghosn, Louis J.

2015-01-01

Advanced environmental barrier coating (EBC) systems for low emission SiCSiC CMC combustors and turbine airfoils have been developed to meet next generation engine emission and performance goals. This presentation will highlight the developments of NASAs current EBC system technologies for SiC-SiC ceramic matrix composite combustors and turbine airfoils, their performance evaluation and modeling progress towards improving the engine SiCSiC component temperature capability and long-term durability. Our emphasis has also been placed on the fundamental aspects of the EBC-CMC creep and fatigue behaviors, and their interactions with turbine engine oxidizing and moisture environments. The EBC-CMC environmental degradation and failure modes, under various simulated engine testing environments, in particular involving high heat flux, high pressure, high velocity combustion conditions, will be discussed aiming at quantifying the protective coating functions, performance and durability, and in conjunction with damage mechanics and fracture mechanics approaches.

75 FR 65005 - Intent To Prepare a Draft Supplemental Environmental Impact Statement (SEIS), Mississippi Barrier...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-21

... Supplemental Environmental Impact Statement (SEIS), Mississippi Barrier Island Restoration, Mississippi Coastal... reduction, shoreline erosion, salt water intrusion and fish and wildlife preservation in three coastal... catastrophic damage to lives, property, and natural resources throughout coastal Mississippi. In response, the...

Experimental and computational study of dielectric barrier discharges for environmental applications

NASA Astrophysics Data System (ADS)

Aerts, Robby

Air pollution has become a major global concern which affects all inhabitants of our precious earth. Nowadays it is fact that our climate is changing and the sea level is rising. Moreover, we are facing an energy crisis because all our fossil fuel resources will sooner or later be running empty. It is clear that drastic measures are needed to keep our planet as it is today for generations to come. One of these measures is the 20-20-20 targets imposed by the European Commission, which stimulates the research for environmental energy applications. In this PhD dissertation two environmental applications of plasma technology are investigated. The first one is the abatement of flue gases, and more specifically the destruction of volatile organic compounds (VOCs). The second one is the conversion of CO2 into valuable chemicals. Both of these applications suffer from a large energy cost under classical (thermodynamic) conditions, due to the chemical stability of these molecules. Plasma technology is quite promising to overcome these thermodynamic barriers. Plasmas allow reactions at different time-scales with different species, such as electrons, ions, radicals, molecules and excited species, creating new chemical pathways. Indeed, in a plasma the applied electrical energy is directly transferred to the electrons, which activate the gas by ionization, excitation and dissociation, hence creating reactive species (ions, excited species, radicals), that can further easily undergo other chemical reactions. Especially gas discharges, which are low temperature plasmas, show promising results in the destruction of pollutants at mild conditions. A common type of gas discharge is the dielectric barrier discharge (DBD) which has been successfully scaled up for industrial ozone generation and is widely investigated in the field of environmental applications. The complexity of DBDs creates difficulties for experimental diagnostics and therefore numerical studies can help to improve

Development of Reliability Based Life Prediction Methods for Thermal and Environmental Barrier Coatings in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Shah, Ashwin

2001-01-01

Literature survey related to the EBC/TBC (environmental barrier coating/thermal barrier coating) fife models, failure mechanisms in EBC/TBC and the initial work plan for the proposed EBC/TBC life prediction methods development was developed as well as the finite element model for the thermal/stress analysis of the GRC-developed EBC system was prepared. Technical report for these activities is given in the subsequent sections.

Advanced thermal barrier coatings for operation in high hydrogen content fueled gas turbines.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sampath, Sanjay

2015-04-02

The Center for Thermal Spray Research (CTSR) at Stony Brook University in partnership with its industrial Consortium for Thermal Spray Technology is investigating science and technology related to advanced metallic alloy bond coats and ceramic thermal barrier coatings for applications in the hot section of gasified coal-based high hydrogen turbine power systems. In conjunction with our OEM partners (GE and Siemens) and through strategic partnership with Oak Ridge National Laboratory (ORNL) (materials degradation group and high temperature materials laboratory), a systems approach, considering all components of the TBC (multilayer ceramic top coat, metallic bond coat & superalloy substrate) is beingmore » taken during multi-layered coating design, process development and subsequent environmental testing. Recent advances in process science and advanced in situ thermal spray coating property measurement enabled within CTSR has been incorporated for full-field enhancement of coating and process reliability. The development of bond coat processing during this program explored various aspects of processing and microstructure and linked them to performance. The determination of the bond coat material was carried out during the initial stages of the program. Based on tests conducted both at Stony Brook University as well as those carried out at ORNL it was determined that the NiCoCrAlYHfSi (Amdry) bond coats had considerable benefits over NiCoCrAlY bond coats. Since the studies were also conducted at different cycling frequencies, thereby addressing an associated need for performance under different loading conditions, the Amdry bond coat was selected as the material of choice going forward in the program. With initial investigations focused on the fabrication of HVOF bond coats and the performance of TBC under furnace cycle tests , several processing strategies were developed. Two-layered HVOF bond coats were developed to render optimal balance of density and surface

Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

ERIC Educational Resources Information Center

Draper, Alison J.

2004-01-01

An active service-learning research work is conducted in the field of advanced environmental chemistry. Multiple projects are assigned to students, which promote individual learning skills, self-confidence as scientists, and a deep understanding of the environmental chemist's profession.

Understanding and Addressing Barriers to Implementation of Environmental and Policy Interventions to Support Physical Activity and Healthy Eating in Rural Communities

PubMed Central

Barnidge, Ellen K.; Radvanyi, Catherine; Duggan, Kathleen; Motton, Freda; Wiggs, Imogene; Baker, Elizabeth A.; Brownson, Ross C.

2016-01-01

PURPOSE Rural residents are at greater risk of obesity than urban and suburban residents. Failure to meet physical activity and healthy eating recommendations play a role. Emerging evidence shows the effectiveness of environmental and policy interventions to promote physical activity and healthy eating. Yet most of the evidence comes from urban and suburban communities. The objectives of this study were to 1) identify types of environmental and policy interventions being implemented in rural communities to promote physical activity or healthy eating, 2) identify barriers to the implementation of environmental or policy interventions, and 3) identify strategies rural communities have employed to overcome these barriers. METHODS Key informant interviews with public health professionals working in rural areas in the United States were conducted in 2010. A purposive sample included 15 practitioners engaged in planning, implementing, or evaluating environmental or policy interventions to promote physical activity or healthy eating. FINDINGS Our findings reveal that barriers in rural communities include cultural differences, population size, limited human capital, and difficulty demonstrating the connection between social and economic policy and health outcomes. Key informants identified a number of strategies to overcome these barriers such as developing broad-based partnerships and building on the existing infrastructure. CONCLUSON Recent evidence suggests that environmental and policy interventions have potential to promote physical activity and healthy eating at the population level. To realize positive outcomes, it is important to provide opportunities to implement these types of interventions and document their effectiveness in rural communities. PMID:23289660

Liquid Feedstock Plasma Spraying: An Emerging Process for Advanced Thermal Barrier Coatings

NASA Astrophysics Data System (ADS)

Markocsan, Nicolaie; Gupta, Mohit; Joshi, Shrikant; Nylén, Per; Li, Xin-Hai; Wigren, Jan

2017-08-01

Liquid feedstock plasma spraying (LFPS) involves deposition of ultrafine droplets of suspensions or solution precursors (typically ranging from nano- to submicron size) and permits production of coatings with unique microstructures that are promising for advanced thermal barrier coating (TBC) applications. This paper reviews the recent progress arising from efforts devoted to development of high-performance TBCs using the LFPS approach. Advancements in both suspension plasma spraying and solution precursor plasma spraying, which constitute the two main variants of LFPS, are presented. Results illustrating the different types of the microstructures that can be realized in LFPS through appropriate process parameter control, model-assisted assessment of influence of coating defects on thermo-mechanical properties and the complex interplay between pore coarsening, sintering and crystallite growth in governing thermal conductivity are summarized. The enhancement in functional performances/lifetime possible in LFPS TBCs with multilayered architectures and by incorporating new pyrochlore chemistries such as gadolinium zirconate, besides the conventional single 8 wt.% yttria-stabilized zirconia insulating ceramic layer, is specifically highlighted.

Barriers to Expanding Advanced Pharmacy Practice Experience Site Availability in an Experiential Education Consortium

PubMed Central

Byrd, Debbie C.; Duke, Lori J.; Fetterman, James W.; Unterwagner, Whitney L.; Staton, April G.; Miller, Mindi S.; Sheffield, Melody C.; Kennedy, William K.; McDuffie, Charles H.; Stevenson, T. Lynn; Thompson, Paula A.; McCullough, Elizabeth S.

2009-01-01

Objectives To compare 2006-2007 and projected 2010-2011 advanced pharmacy practice experience (APPE) availability and needs for 4 colleges and schools of pharmacy in Georgia and Alabama and to examine barriers and offer potential solutions to increase APPE site and preceptor availability. Methods Data on APPE needs and availability were gathered prospectively and evaluated relative to current and projected enrollment and planned programmatic changes. Results Combined 2006-2007 non-community APPE needs and availabilities were 3,590 and 4,427, respectively, with a surplus availability of 837. Combined projected 2010-2011 non-community APPEs were estimated at 4,309. Assuming 2006-2007 non-community availability remained unchanged, the surplus availability declined to 118. Conclusions The need for quality experiential education represents a significant barrier and rate-limiting step to the matriculation of the increased numbers of pharmacists. Barriers to expanding APPE availability include: introductory pharmacy practice experience (IPPE) and APPE expansion, growth of new and existing pharmacy programs, financial instability of acute care facilities, and lack of preceptor development resources. Regional experiential education consortiums can provide a constructive approach to improve access to quality sites and preceptors through standardizing processes and leveraging resources. PMID:19777097

Life Prediction Issues in Thermal/Environmental Barrier Coatings in Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Shah, Ashwin R.; Brewer, David N.; Murthy, Pappu L. N.

2001-01-01

Issues and design requirements for the environmental barrier coating (EBC)/thermal barrier coating (TBC) life that are general and those specific to the NASA Ultra-Efficient Engine Technology (UEET) development program have been described. The current state and trend of the research, methods in vogue related to the failure analysis, and long-term behavior and life prediction of EBCITBC systems are reported. Also, the perceived failure mechanisms, variables, and related uncertainties governing the EBCITBC system life are summarized. A combined heat transfer and structural analysis approach based on the oxidation kinetics using the Arrhenius theory is proposed to develop a life prediction model for the EBC/TBC systems. Stochastic process-based reliability approach that includes the physical variables such as gas pressure, temperature, velocity, moisture content, crack density, oxygen content, etc., is suggested. Benefits of the reliability-based approach are also discussed in the report.

Maternal exposure to carbamazepine at environmental concentrations can cross intestinal and placental barriers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaushik, Gaurav, E-mail: kausgaur@isu.edu; Department of Medical Pathology and Laboratory Medicine, University of California at Davis, Davis, CA 95817; Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children, Northern California, 2425 Stockton Boulevard, Sacramento, CA 95817

Psychoactive pharmaceuticals have been found as teratogens at clinical dosage during pregnancy. These pharmaceuticals have also been detected in minute (ppb) concentrations in drinking water in the US, and are environmental contaminants that may be complicit in triggering neurological disorders in genetically susceptible individuals. Previous studies have determined that psychoactive pharmaceuticals (fluoxetine, venlafaxine and carbamazepine) at environmentally relevant concentrations enriched sets of genes regulating development and function of the nervous system in fathead minnows. Altered gene sets were also associated with potential neurological disorders, including autism spectrum disorders (ASD). Subsequent in vitro studies indicated that psychoactive pharmaceuticals altered ASD-associated synaptic proteinmore » expression and gene expression in human neuronal cells. However, it is unknown if environmentally relevant concentrations of these pharmaceuticals are able to cross biological barriers from mother to fetus, thus potentially posing risks to nervous system development. The main objective of this study was to test whether psychoactive pharmaceuticals (fluoxetine, venlafaxine, and carbamazepine) administered through the drinking water at environmental concentrations to pregnant mice could reach the brain of the developing embryo by crossing intestinal and placental barriers. We addressed this question by adding {sup 2}H-isotope labeled pharmaceuticals to the drinking water of female mice for 20 days (10 pre-and 10 post–conception days), and quantifying {sup 2}H-isotope enrichment signals in the dam liver and brain of developing embryos using isotope ratio mass spectrometry. Significant levels of {sup 2}H enrichment was detected in the brain of embryos and livers of carbamazepine-treated mice but not in those of control dams, or for fluoxetine or venlafaxine application. These results provide the first evidence that carbamazepine in drinking water and

Social and Environmental Barriers to Nutrition Therapy for Diabetes Management Among Underserved Pregnant Women: A Qualitative Analysis.

PubMed

Yee, Lynn M; McGuire, Jamie M; Taylor, Shaneah M; Niznik, Charlotte M; Simon, Melissa A

2016-03-01

To identify social and environmental barriers to nutrition therapy for diabetes management during pregnancy among a population of low-income, minority pregnant women. Prospective, in-depth, semi-structured interviews performed serially during pregnancy and continued until thematic saturation was reached. Urban academic medical center. Ten pregnant low-income, minority women with gestational diabetes and type 2 diabetes mellitus. Social and environmental barriers to nutrition therapy for diabetes management during pregnancy. Qualitative analysis of interview data using electronic coding software was performed using theme analysis. Participants perceived limited ability and self-efficacy to adopt nutrition recommendations. Specific themes identified as barriers included (1) feeling overwhelmed by the unfamiliar; (2) using and decoding nutrition labels; (3) managing nutrition choices and seeking control in the setting of food insecurity; (4) experiencing lack of control and motivation, and limited self-efficacy; (5) balancing recommendations with taste preferences and cultural food norms; (6) maintaining a healthy eating schedule; and (7) accommodating diabetes in family and social life. Pregnant women with diabetes encounter a number of knowledge-based, attitudinal, and resource-related barriers that reduce capacity for nutrition therapy adherence. Provision of culturally informed, practical nutrition support that addresses the needs of women in low-resource communities is an important component of comprehensive diabetes care during pregnancy. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Environmental Barrier Coatings (EBC) for Ceramic Matrix Composite (CMC) Materials

NASA Technical Reports Server (NTRS)

Lee,Kang

2001-01-01

The upper use temperature of current Environmental Barrier Coatings (EBC's) based on mullite and BSAS (EPM EBC's) is limited to -255 F due to silica volatility, chemical reactions, and high thermal conductivity. Therefore, new EBC s having low CTE, good chemical compatibility, and high melting point (greater than 2700 F ) are being investigated. Sinter-resistant, low thermal conductivity EBC s are strongly desired to achieve the UEET EBC goal of 270 F EBC surface temperature and 30 F AT over long exposures (greater than 1000 hr). Key areas affecting the upper temperature limit of current EBC s as well as the ongoing efforts to develop next generation EBC s in the UEET Program will be discussed.

Thermal Cycling and High-Temperature Corrosion Tests of Rare Earth Silicate Environmental Barrier Coatings

NASA Astrophysics Data System (ADS)

Darthout, Émilien; Gitzhofer, François

2017-12-01

Lutetium and yttrium silicates, enriched with an additional secondary zirconia phase, environmental barrier coatings were synthesized by the solution precursor plasma spraying process on silicon carbide substrates. A custom-made oven was designed for thermal cycling and water vapor corrosion testing. The oven can test four specimens simultaneously and allows to evaluate environmental barrier performances under similar corrosion kinetics compared to turbine engines. Coatings structural evolution has been observed by SEM on the polished cross sections, and phase composition has been analyzed by XRD. All coatings have been thermally cycled between 1300 °C and the ambient temperature, without spallation, due to their porosity and the presence of additional secondary phase which increases the thermal cycling resistance. During water vapor exposure at 1200 °C, rare earth disilicates showed a good stability, which is contradictory with the literature, due to impurities—such as Si- and Al-hydroxides—in the water vapor jets. The presence of vertical cracks allowed the water vapor to reach the substrate and then to corrode it. It has been observed that thin vertical cracks induced some spallation after 24 h of corrosion.

Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming

2005-01-01

Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future engine higher fuel efficiency and lower emission goals. In this presentation, thermal barrier coating development considerations and requirements will be discussed. An experimental approach is established to monitor in real time the thermal conductivity of the coating systems subjected to high-heat-flux, steady-state and cyclic temperature gradients. Advanced low conductivity thermal barrier coatings have also been developed using a multi-component defect clustering approach, and shown to have improved thermal stability. The durability and erosion resistance of low conductivity thermal barrier coatings have been improved utilizing advanced coating architecture design, composition optimization, in conjunction with more sophisticated modeling and design tools.

Barriers to Career Mobility/Advancement by African-American and Caucasian Female Administrators in Minnesota Organizations: A Perception or Reality?

ERIC Educational Resources Information Center

Coleman, Jo Evans

The primary purpose of this research was to identify perceived barriers affecting African-American and Caucasian female administrators' career mobility/advancement in education, business/industry, and government in Minnesota. The study explored women's perceptions of the effects that race/gender discrimination and gender underrepresentation have…

Environmental Applications of Biosurfactants: Recent Advances

PubMed Central

Pacwa-Płociniczak, Magdalena; Płaza, Grażyna A.; Piotrowska-Seget, Zofia; Cameotra, Swaranjit Singh

2011-01-01

Increasing public awareness of environmental pollution influences the search and development of technologies that help in clean up of organic and inorganic contaminants such as hydrocarbons and metals. An alternative and eco-friendly method of remediation technology of environments contaminated with these pollutants is the use of biosurfactants and biosurfactant-producing microorganisms. The diversity of biosurfactants makes them an attractive group of compounds for potential use in a wide variety of industrial and biotechnological applications. The purpose of this review is to provide a comprehensive overview of advances in the applications of biosurfactants and biosurfactant-producing microorganisms in hydrocarbon and metal remediation technologies. PMID:21340005

Permeable bio-reactive barriers to address petroleum hydrocarbon contamination at subantarctic Macquarie Island.

PubMed

Freidman, Benjamin L; Terry, Deborah; Wilkins, Dan; Spedding, Tim; Gras, Sally L; Snape, Ian; Stevens, Geoffrey W; Mumford, Kathryn A

2017-05-01

A reliance on diesel generated power and a history of imperfect fuel management have created a legacy of petroleum hydrocarbon contamination at subantarctic Macquarie Island. Increasing environmental awareness and advances in contaminant characterisation and remediation technology have fostered an impetus to reduce the environmental risk associated with legacy sites. A funnel and gate permeable bio-reactive barrier (PRB) was installed in 2014 to address the migration of Special Antarctic Blend diesel from a spill that occurred in 2002, as well as older spills and residual contaminants in the soil at the Main Power House. The PRB gate comprised of granular activated carbon and natural clinoptilolite zeolite. Petroleum hydrocarbons migrating in the soil water were successfully captured on the reactive materials, with concentrations at the outflow of the barrier recorded as being below reporting limits. The nutrient and iron concentrations delivered to the barrier demonstrated high temporal variability with significant iron precipitation observed across the bed. The surface of the granular activated carbon was largely free from cell attachment while natural zeolite demonstrated patchy biofilm formation after 15 months following PRB installation. This study illustrates the importance of informed material selection at field scale to ensure that adsorption and biodegradation processes are utilised to manage the environmental risk associated with petroleum hydrocarbon spills. This study reports the first installation of a permeable bio-reactive barrier in the subantarctic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Engaging Neuroscience to Advance Translational Research in Brain Barrier Biology

PubMed Central

Neuwelt, Edward A.; Bauer, Björn; Fahlke, Christoph; Fricker, Gert; Iadecola, Constantino; Janigro, Damir; Leybaert, Luc; Molnar, Zoltan; O’Donnell, Martha; Povlishock, John; Saunders, Norman; Sharp, Frank; Stanimirovic, Danica; Watts, Ryan; Drewes, Lester

2012-01-01

Preface The delivery of many potentially therapeutic and diagnostic compounds to specific areas of the brain is restricted by brain barriers, the most well known of which are the blood-brain barrier (BBB) and the blood-cerebrospinal fluid (CSF) barrier. Recent studies have shown numerous additional roles of these barriers, including an involvement in neurodevelopment, control of cerebral blood flow, and, when barrier integrity is impaired, a contribution to the pathology of many common CNS disorders such as Alzheimer’s disease, Parkinson’s disease and stroke. Thus, many key areas of neuroscientific investigation are shared with the ‘brain barriers sciences’. However, despite this overlap there has been little crosstalk. This lack of crosstalk is of more than academic interest as our emerging understanding of the neurovascular unit (NVU), composed of local neuronal circuits, glia, pericytes and the endothelium, illustrates how the brain dynamically modulates its blood flow, metabolism, and electrophysiological regulation. A key insight is that the barriers are an essential part of the NVU and as such are influenced by all cellular elements of this unit. PMID:21331083

Developing and sustaining specialist and advanced practice roles in nursing and midwifery: A discourse on enablers and barriers.

PubMed

Fealy, Gerard M; Casey, Mary; O'Leary, Denise F; Mcnamara, Martin S; O'Brien, Denise; O'Connor, Laserina; Smith, Rita; Stokes, Diarmuid

2018-06-12

The aim of this discursive paper is to collate, synthesise and discuss published evidence and expert professional opinion on enablers and barriers to the development and sustainability of specialist and advanced practice roles in nursing and midwifery. Expanded practice is a response to population health needs, healthcare costs and practitioners' willingness to expand their scope of practice through enhanced responsibility, accountability and professional autonomy. This discursive paper is based on a rapid review of literature on enablers and barriers to the development and sustainability of specialist and advanced practice roles and is part of a wider policy analysis. We analysed and synthesised of 36 research articles, reviews and discussion papers on enablers and barriers in the development and sustainability of expanded practice roles. Several factors enable role expansion, including: role clarity; credentialing and endorsement; availability of education for expanded roles; individual practitioners' dispositions towards role expansion; support from peers, other professionals and the work organisation; and costs. Where limited or absent, these same factors can constrain role expansion. Enabling nurses and midwives to practice to their full scope of education and expertise is a global challenge for disciplinary leadership, a national challenge for professional regulation, and a local challenge for employers and individual clinicians. These challenges need to be addressed through multi-stakeholder coordinated efforts at these four levels. This discursive paper synthesises empirical evidence and expert professional opinion on the factors that enable or hinder the development and sustainability of specialist and advanced practice roles. Providing a critical appraisal of current knowledge, it provides a reference source for disciplinary debate and policy development regarding the nursing and midwifery resource and informs clinicians of the myriad issues that can

Environmental and Psychosocial Barriers to and Benefits of Cervical Cancer Screening in Kenya

PubMed Central

Ragan, Kathleen; Lee Smith, Judith; Saraiya, Mona; Aketch, Millicent

2017-01-01

Abstract Background. Cervical cancer is the second most commonly diagnosed cancer in females and is a leading cause of cancer‐related mortality in Kenya; limited cervical cancer screening services may be a factor. Few studies have examined men's and women's perceptions on environmental and psychosocial barriers and benefits related to screening. Materials and Methods. In 2014, 60 women aged 25–49 years and 40 male partners participated in 10 focus groups (6 female and 4 male), in both rural and urban settings (Nairobi and Nyanza, Kenya), to explore perceptions about barriers to and benefits of cervical cancer screening. Focus groups were segmented by sex, language, geographic location, and screening status. Data were transcribed, translated into English, and analyzed by using qualitative software. Results. Participants identified screening as beneficial for initiating provider discussions about cancer but did not report it as a beneficial method for detecting precancers. Perceived screening barriers included access (transportation, cost), spousal approval, stigma, embarrassment during screening, concerns about speculum use causing infertility, fear of residual effects of test results, lack of knowledge, and religious or cultural beliefs. All participants reported concerns with having a male doctor perform screening tests; however, men uniquely reported the young age of a doctor as a barrier. Conclusion. Identifying perceived barriers and benefits among people in low‐ and middle‐income countries is important to successfully implementing emerging screening programs. The novel findings on barriers and benefits from this study can inform the development of targeted community outreach activities, communication strategies, and educational messages for patients, families, and providers. Implications for Practice. This article provides important information for stakeholders in clinical practice and research when assessing knowledge, beliefs, and acceptability of

Evaluating the Social Validity of Project "TEAM": A Problem-Solving Intervention to Teach Transition Age Youth with Developmental Disabilities to Resolve Environmental Barriers

ERIC Educational Resources Information Center

Kramer, Jessica M.; Hwang, I-Ting; Helfrich, Christine A.; Samuel, Preethy S.; Carrellas, Ann

2018-01-01

Project "TEAM" teaches transition-age youth with developmental disabilities (DD) to identify physical and social environmental barriers and supports, generate solutions to barriers, and request modifications to increase participation. Establishing the social validity of this environment focused intervention with youth and their parents…

The Cementitious Barriers Partnership Experimental Programs and Software Advancing DOE’s Waste Disposal/Tank Closure Efforts – 15436

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, Heather; Flach, Greg; Smith, Frank

2015-01-27

The U.S. Department of Energy Environmental Management (DOE-EM) Office of Tank Waste Management-sponsored Cementitious Barriers Partnership (CBP) is chartered with providing the technical basis for implementing cement-based waste forms and radioactive waste containment structures for long-term disposal. DOE needs in this area include the following to support progress in final treatment and disposal of legacy waste and closure of High-Level Waste (HLW) tanks in the DOE complex: long-term performance predictions, flow sheet development and flow sheet enhancements, and conceptual designs for new disposal facilities. The DOE-EM Cementitious Barriers Partnership is producing software and experimental programs resulting in new methods andmore » data needed for end-users involved with environmental cleanup and waste disposal. Both the modeling tools and the experimental data have already benefited the DOE sites in the areas of performance assessments by increasing confidence backed up with modeling support, leaching methods, and transport properties developed for actual DOE materials. In 2014, the CBP Partnership released the CBP Software Toolbox –“Version 2.0” which provides concrete degradation models for 1) sulfate attack, 2) carbonation, and 3) chloride initiated rebar corrosion, and includes constituent leaching. These models are applicable and can be used by both DOE and the Nuclear Regulatory Commission (NRC) for service life and long-term performance evaluations and predictions of nuclear and radioactive waste containment structures across the DOE complex, including future SRS Saltstone and HLW tank performance assessments and special analyses, Hanford site HLW tank closure projects and other projects in which cementitious barriers are required, the Advanced Simulation Capability for Environmental Management (ASCEM) project which requires source terms from cementitious containment structures as input to their flow simulations, regulatory reviews of DOE

Through seniors' eyes: an exploratory qualitative study to identify environmental barriers to and facilitators of walking.

PubMed

Lockett, Donna; Willis, Alette; Edwards, Nancy

2005-09-01

This qualitative exploratory study examined environmental factors influencing the walking choices of elderly people using the photovoice approach. A total of 13 seniors in Ottawa, Canada, took photographs of barriers to and facilitators of walking in their neighbourhoods. These photos were displayed during 3 focus-group sessions and served as touchstones for discussion. A total of 22 seniors, including 8 of the 13 photographers, participated in the focus-group sessions. The findings show that environmental hazards related to traffic and falls risks can be significant barriers to walking for seniors, and that connectivity can truly exist for the elderly only if convenience, hazard-free routes are available. They also indicate that simple amenities such as benches and washrooms might facilitate walking for seniors. A neighbourhood that is activity-friendly for seniors will also be a good place for everyone else to live, work, and play. The use of photovoice as a method was well received by the participants and provided rich information that may not have been captured through other means.

Advances in environmental and occupational disorders in 2013.

PubMed

Peden, David B; Bush, Robert K

2014-05-01

In this review of articles published in the Journal in 2013, we report on the significant advances in environmental and occupational disorders. Research advances have led to the identification and defined the structure and function of several major allergens. A meta-analysis confirmed the importance of mold exposure in patients with allergic rhinitis, and a new immunologic classification of aspergillosis emerged. Insights into the role of diesel exhaust particles in patients with severe asthma were clarified. Improvements in stinging insect allergy diagnostics were reported. Genetic, immunologic, and biomarker studies advanced the understanding of adverse drug reactions. New practice parameters for cockroach allergen control were presented. The pathologic role of viruses and bacterial agents in patients with asthma and chronic obstructive pulmonary disease were further defined. An excellent review of allergen bronchoprovocation testing was reported. The roles of bronchoprovocation and bronchodilator responsiveness in asthma diagnosis were further clarified. A biomarker for neutrophilic asthma was identified. Therapeutic advances in asthma research include the inhibition of IL-13 by lebrikizumab, use of montelukast in asthmatic smokers, and a thorough review of bronchial thermoplasty in patients with severe asthma. Lastly, maternal asthma was linked to a number of adverse neonatal outcomes. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Thermochemistry of CaO-MgO-Al2O3-SiO2 (CMAS) and Advanced Thermal and Environmental Barrier Coating Systems

NASA Technical Reports Server (NTRS)

Costa, Gustavo C. C.; Zhu, Dongming

2016-01-01

CaO-MgO-Al2O3-SiO2 (CMAS) oxides are constituents in a broad number of materials and minerals which have recently inferred to discussions in materials science, planetary science, geochemistry and cosmochemistry communities. In materials science, there is increasing interest in the degradation studies of thermal (TBC) and environmental (EBC) barrier coatings of gas turbines by molten CMAS. These coatings have been explored to be applied on silicon-based ceramics and composites which are lighter and more temperature capable hot-section materials of gas turbines than the current Ni-based superalloys. The degradation of the coatings occurs when CMAS minerals carried by the intake air into gas turbines, e.g. in aircraft engines, reacts at high temperatures (1000C) with the coating materials. This causes premature failure of the static and rotating components of the turbine engines. We discuss some preliminary results of the reactions between CMAS and Rare-Earth (RE Y, Yb and Gd) oxide stabilized ZrO2 systems, and stability of the resulting oxides and silicates.

Advanced microscopic methods for the detection of adhesion barriers in immunology in medical imaging

NASA Astrophysics Data System (ADS)

Lawrence, Shane

2017-07-01

Advanced methods of microscopy and advanced techniques of analysis stemming therefrom have developed greatly in the past few years.The use of single discrete methods has given way to the combination of methods which means an increase in data for processing to progress to the analysis and diagnosis of ailments and diseases which can be viewed by each and any method.This presentation shows the combination of such methods and gives example of the data which arises from each individual method and the combined methodology and suggests how such data can be streamlined to enable conclusions to be drawn about the particular biological and biochemical considerations that arise.In this particular project the subject of the methodology was human lactoferrin and the relation of the adhesion properties of hlf in the overcoming of barriers to adhesion mainly on the perimeter of the cellular unit and how this affects the process of immunity in any particular case.

CARD-FISH for Environmental Microorganisms: Technical Advancement and Future Applications

PubMed Central

Kubota, Kengo

2013-01-01

Fluorescence in situ hybridization (FISH) has become a standard technique in environmental microbiology. More than 20 years have passed since this technique was first described, and it is currently used for the detection of ribosomal RNA, messenger RNA, and functional genes encoded on chromosomes. This review focuses on the advancement and applications of FISH combined with catalyzed reporter deposition (CARD, also known as tyramide signal amplification or TSA), in the detection of environmental microorganisms. Significant methodological improvements have been made in CARD-FISH technology, including its combination with other techniques and instruments. PMID:23124765

Emerging Skin T-Cell Functions in Response to Environmental Insults

PubMed Central

Suwanpradid, Jutamas; Holcomb, Zachary E.; MacLeod, Amanda S.

2017-01-01

Skin is the primary barrier between the body and the outside world, functioning not only as a physical barrier, but also as an immunologic first line of defense. A large number of T cells populate the skin. This review highlights the ability of these cutaneous T cells to regulate skin-specific environmental threats, including microbes, injuries, solar UV radiation, and allergens. Since much of this knowledge has been advanced from murine studies, we focus our review on how the mouse state has informed the human state, emphasizing the key parallels and differences. PMID:27784595

The barriers to environmental sustainability in post-disaster settings: a case study of transitional shelter implementation in Haiti.

PubMed

Abrahams, Daniel

2014-04-01

Disaster recovery operations that do not account for environmental sustainability (ES) risk exacerbating the impact of the disaster and hindering long-term recovery efforts. Yet aid agencies do not always consider ES. This research is a case study of the recovery that followed the 2010 earthquake in Haiti. Using timber and concrete procurement as proxies for broader post-disaster operations, research examined perceptions of ES as well as attempts at and barriers to incorporating it into programming. Identified barriers can be grouped into two categories: (1) prioritisations and perceptions within the disaster response sector that resulted in limited enthusiasm for incorporating ES into programming, and (2) structural and organisational barriers within the disaster response framework that impeded ES attempts and served as a further disincentive to incorporating ES into programming. As a result of those barriers, incorporation of ES was sporadic and inconsistent and often depended on the capacity and motivation of specific implementers. © 2014 The Author(s). Disasters © Overseas Development Institute, 2014.

Dissecting gene expression at the blood-brain barrier

PubMed Central

Huntley, Melanie A.; Bien-Ly, Nga; Daneman, Richard; Watts, Ryan J.

2014-01-01

The availability of genome-wide expression data for the blood-brain barrier is an invaluable resource that has recently enabled the discovery of several genes and pathways involved in the development and maintenance of the blood-brain barrier, particularly in rodent models. The broad distribution of published data sets represents a viable starting point for the molecular dissection of the blood-brain barrier and will further direct the discovery of novel mechanisms of blood-brain barrier formation and function. Technical advances in purifying brain endothelial cells, the key cell that forms the critical barrier, have allowed for greater specificity in gene expression comparisons with other central nervous system cell types, and more systematic characterizations of the molecular composition of the blood-brain barrier. Nevertheless, our understanding of how the blood-brain barrier changes during aging and disease is underrepresented. Blood-brain barrier data sets from a wider range of experimental paradigms and species, including invertebrates and primates, would be invaluable for investigating the function and evolution of the blood-brain barrier. Newer technologies in gene expression profiling, such as RNA-sequencing, now allow for finer resolution of transcriptomic changes, including isoform specificity and RNA-editing. As our field continues to utilize more advanced expression profiling in its ongoing efforts to elucidate the blood-brain barrier, including in disease and drug delivery, we will continue to see rapid advances in our understanding of the molecular mediators of barrier biology. We predict that the recently published data sets, combined with forthcoming genomic and proteomic blood-brain barrier data sets, will continue to fuel the molecular genetic revolution of blood-brain barrier biology. PMID:25414634

Environmental Records from Great Barrier Reef Corals: Inshore versus Offshore Drivers

PubMed Central

Walther, Benjamin D.; Kingsford, Michael J.; McCulloch, Malcolm T.

2013-01-01

The biogenic structures of stationary organisms can be effective recorders of environmental fluctuations. These proxy records of environmental change are preserved as geochemical signals in the carbonate skeletons of scleractinian corals and are useful for reconstructions of temporal and spatial fluctuations in the physical and chemical environments of coral reef ecosystems, including The Great Barrier Reef (GBR). We compared multi-year monitoring of water temperature and dissolved elements with analyses of chemical proxies recorded in Porites coral skeletons to identify the divergent mechanisms driving environmental variation at inshore versus offshore reefs. At inshore reefs, water Ba/Ca increased with the onset of monsoonal rains each year, indicating a dominant control of flooding on inshore ambient chemistry. Inshore multi-decadal records of coral Ba/Ca were also highly periodic in response to flood-driven pulses of terrigenous material. In contrast, an offshore reef at the edge of the continental shelf was subject to annual upwelling of waters that were presumed to be richer in Ba during summer months. Regular pulses of deep cold water were delivered to the reef as indicated by in situ temperature loggers and coral Ba/Ca. Our results indicate that although much of the GBR is subject to periodic environmental fluctuations, the mechanisms driving variation depend on proximity to the coast. Inshore reefs are primarily influenced by variable freshwater delivery and terrigenous erosion of catchments, while offshore reefs are dominated by seasonal and inter-annual variations in oceanographic conditions that influence the propensity for upwelling. The careful choice of sites can help distinguish between the various factors that promote Ba uptake in corals and therefore increase the utility of corals as monitors of spatial and temporal variation in environmental conditions. PMID:24204743

Barriers to activity and participation for stroke survivors in rural China.

PubMed

Zhang, Lifang; Yan, Tiebin; You, Liming; Li, Kun

2015-07-01

To investigate environmental barriers reported by stroke survivors in the rural areas of China and to determine the impact of environmental barriers on activity and participation relative to demographic characteristics and body functioning. Cross-sectional survey. Structured interviews in the participants' homes. Community-dwelling stroke survivors in the rural areas of China (N=639). Not applicable. Activity and participation (Chinese version of the World Health Organization Disability Assessment Schedule 2.0), environmental barriers (Craig Hospital Inventory of Environmental Factors), neurological function (Canadian Neurological Scale), cognitive function (Abbreviated Mental Test), and depression (6-item Hamilton Rating Scale for Depression). Physical/structural barriers are the major impediment to activity and participation for these participants (odds ratio, 1.86 and 1.99 for activity and participation, respectively; P<.01). Services/assistance barriers primarily impede participation rather than activity (odds ratio, 1.58 in participation; P<.05). Physical/structural and services/assistance barriers were considered the dominant barriers to activity and participation for stroke survivors in the rural areas of China. Attitudinal/support and policy barriers did not emerge as serious concerns. To generate an enabling environment, physical/structural and services/assistance barriers are the environmental barriers to be decreased and eliminated first. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The Environmental Control and Life Support System (ECLSS) advanced automation project

NASA Technical Reports Server (NTRS)

Dewberry, Brandon S.; Carnes, Ray

1990-01-01

The objective of the environmental control and life support system (ECLSS) Advanced Automation Project is to influence the design of the initial and evolutionary Space Station Freedom Program (SSFP) ECLSS toward a man-made closed environment in which minimal flight and ground manpower is needed. Another objective includes capturing ECLSS design and development knowledge future missions. Our approach has been to (1) analyze the SSFP ECLSS, (2) envision as our goal a fully automated evolutionary environmental control system - an augmentation of the baseline, and (3) document the advanced software systems, hooks, and scars which will be necessary to achieve this goal. From this analysis, prototype software is being developed, and will be tested using air and water recovery simulations and hardware subsystems. In addition, the advanced software is being designed, developed, and tested using automation software management plan and lifecycle tools. Automated knowledge acquisition, engineering, verification and testing tools are being used to develop the software. In this way, we can capture ECLSS development knowledge for future use develop more robust and complex software, provide feedback to the knowledge based system tool community, and ensure proper visibility of our efforts.

Thermochemistry of Calcium-Magnesium-Aluminum-Silicate (CMAS) and Components of Advanced Thermal and Environmental Barrier Coating Systems

NASA Technical Reports Server (NTRS)

Costa, Gustavo C. C.; Acosta, Waldo A.; Zhu, Dongming; Ghoshal, Anindya

2017-01-01

There is increasing interest in the degradation mechanism studies of thermal and environmental barrier coatings (TEBCs) of gas turbines by molten CaO-MgO-Al(exp. 2)O(exp. 3)-SiO(exp. 2) CMAS). CMAS minerals are usually referred as silicon-containing sand dust and volcano ash materials that are carried by the intake air into gas turbines, e.g. in aircraft engines, and their deposits often react at high temperatures (greater than 1200 degrees C) with the engine turbine coating systems and components. The high temperature reactions causes degradation and accelerated failure of the static and rotating components of the turbine engines. We discuss some results of the reactions between the CMAS and Rare-Earth (RE = Y, Yb, Dy, Gd, Nd and Sm) - oxide stabilized ZrO(exp. 2) or HfO(exp. 2) systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples (outside diameter = 4.7 mm, wall thickness = 0.76 mm and = 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat treated at 1310 degrees C for 5h. Samples were characterized by differential scanning calorimetry (DSC), X-ray diffraction, and cross-section electron microscopy analysis and energy dispersive X-ray spectroscopy. It was found that CMAS penetrated the samples at the grain boundaries and dissolved the TEBC materials to form silicate phases containing the rare-earth elements. Furthermore, it was found that apatite crystalline phases were formed in the samples with total rare-earth content higher than 12 mol% in the reaction zone for the ZrO(exp. 2) system. In general, samples with the nominal compositions (30YSZ), HfO(exp. 2)-7Dy(exp. 2)O(exp. 2) and ZrO(exp. 2)-9.5Y(exp. 2)O(exp. 3)-2.25Gd(exp. 2)O(exp. 3)-2.25Yb(exp. 2)O(exp. 3) exhibited lower reactivity or more resistance to CMAS than the other coating compositions of this work.

Scientific advances provide opportunities to improve pediatric environmental health

USGS Publications Warehouse

Reddy, Michael M.; Reddy, Micaela B.; Reddy, Carol F.

2004-01-01

The health consequences of contaminants in the environment, with respect to the health of children and infants, recently have been dramatically brought to public attention by the motion pictures Erin Brockovich and A Civil Action. These productions focused public attention on the potential link between water contaminants and pediatric health, a continuing subject of public concern. As a consequence of the increasing production of new commercial chemicals, many chemicals have appeared in the scientific and public awareness as potential threats to health. These new or novel compounds eventually distribute in the environment and often are termed emerging contaminants. Gitterman and Bearer stated, "Children may serve as unwitting sentinels for society; they are often the youngest exposed to many environmental toxicants and may become the youngest in age to manifest adverse responses." The discipline of pediatric environmental health is still in its adolescence, but it will be increasingly important as new chemicals are generated and as more is learned about the health effects of chemicals already in commerce. Here, we provide an overview of recent advances in biomonitoring and environmental monitoring of environmental contaminants including emerging contaminants. Our purpose in writing this commentary is to make pediatricians aware of the current resources available for learning about pediatric environmental health and of ongoing research initiatives that provide opportunities to improve pediatric environmental health.

Development and implementation of Strategic Environmental Assessment in Taiwan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, M.-L.; Yu, Y.-H

2004-04-01

Taiwan is one of the few Asian countries to have officially adopted Strategic Environmental Assessment (SEA) as one important means towards the achievement of environmental conservation and sustainable development. Despite implementation almost a decade ago, SEA remains premature in its development. This paper analyzes the progress and characteristics of SEA in Taiwan and, through examination of its limited case studies, reveals the positive and apparent influence of SEA on policy making. This paper also identifies the barriers hindering SEA's advancement and concludes with recommendations on strategies to overcome these obstacles.

Can people catastrophize barriers? An exploratory analysis of the association between pain catastrophizing and perceptions of environmental factors.

PubMed

Ravesloot, Craig; Berendts, Cathy; Schiwal, Alex

2017-01-01

Measurement of the environment is taking on increased importance for understanding variability in participation. Most measures of the environment use subjective ratings, yet little is known about how people appraise the environment. /Hypothesis: We conducted this post-hoc study to examine whether or not catastrophizing, an important variable for understanding how pain contributes to disability, may be related to ratings of the environment. We hypothesized higher pain catastrophizing scores would be associated with greater environmental barriers and fewer facilitators. Individuals with functional impairments (N = 525) were recruited from a population-based random sample of households in a small western city in the United States to complete a paper-based survey about their health and community living experiences. We conducted exploratory regression analyses to investigate associations with environmental factor ratings. We found substantial associations between pain catastrophizing and both environmental barriers and personal factor problems after controlling for demographics, participation assessed by community trips per week, health conditions, impairment and pain level. The models accounted for 28% of the variance in environmental factor ratings and 52% of the variability personal factor ratings. We also present odds ratios for the association between personal characteristics and the likelihood of endorsing EF and PF. A variety of individual characteristics are associated with ratings of both environmental and personal factors that impact participation. Among these, pain catastrophizing is a robust predictor of EF and PF ratings which suggests future research designed specifically to test this relationship may generate useful results for developing interventions to increase participation. Copyright © 2016 Elsevier Inc. All rights reserved.

How do Dutch primary care providers overcome barriers to advance care planning with older people? A qualitative study.

PubMed

Glaudemans, Jolien J; de Jong, Anja E; Onwuteaka Philipsen, Bregje D; Wind, Jan; Willems, Dick L

2018-06-11

Few older people benefit from advance care planning (ACP), due to several barriers related to primary care professionals, such as insufficient knowledge, negative beliefs and a lack of time. Information on overcoming these barriers is limited. We assumed primary care professionals experienced in ACP with older patients are likely to have learned how to overcome these barriers. To investigate how Dutch primary care professionals experienced in ACP with older patients overcome these barriers. A qualitative study, based on semi-structured interviews, among a purposive sample of 14 Dutch primary care professionals experienced in ACP with older people. Transcripts were thematically analysed. We interviewed eight general practitioners (GPs), three nurses and three elderly care physicians, experienced in ACP with older people. Respondents overcame their own insufficient knowledge and skills, as well as their negative attitudes and beliefs by gaining experience through practicing ACP in their daily practices, exchanging and reflecting on those experiences with peers, pursuing continuing education, teaching and participating in research. To overcome patients' and families' lack of initiative and openness to ACP, respondents prepared them for further steps in ACP. To overcome a lack of time, respondents used tools and information communication technology, delegated parts of ACP to other primary care professionals, acquired financing and systematized documentation of ACP. Primary care professionals can overcome barriers to ACP with older patients by practicing, reflecting on experiences and pursuing continuing education, by preparing patients and involving family and by investing in support to approach ACP more efficiently.

Ultrathin Cr added Ru film as a seedless Cu diffusion barrier for advanced Cu interconnects

NASA Astrophysics Data System (ADS)

Hsu, Kuo-Chung; Perng, Dung-Ching; Yeh, Jia-Bin; Wang, Yi-Chun

2012-07-01

A 5 nm thick Cr added Ru film has been extensively investigated as a seedless Cu diffusion barrier. High-resolution transmission electron microscopy micrograph, X-ray diffraction (XRD) pattern and Fourier transform-electron diffraction pattern reveal that a Cr contained Ru (RuCr) film has a glassy microstructure and is an amorphous-like film. XRD patterns and sheet resistance data show that the RuCr film is stable up to 650 °C, which is approximately a 200 °C improvement in thermal stability as compared to that of the pure Ru film. X-ray photoelectron spectroscopy depth profiles show that the RuCr film can successfully block Cu diffusion, even after a 30-min 650 °C annealing. The leakage current of the Cu/5 nm RuCr/porous SiOCH/Si stacked structure is about two orders of magnitude lower than that of a pristine Ru sample for electric field below 1 MV/cm. The RuCr film can be a promising Cu diffusion barrier for advanced Cu metallization.

Thermochemistry of CaO-MgO-Al2O3-SiO2 (CMAS) and Advanced Thermal and Environmental Barrier Coating Systems

NASA Technical Reports Server (NTRS)

Costa, Gustavo; Zhu, Dongming

2017-01-01

CaO-MgO-Al2O3-SiO2 (CMAS) oxides are constituents in a broad number of materials and minerals which have recently inferred to discussions in materials science, planetary science, geochemistry and cosmochemistry communities. In materials science, there is increasing interest in the degradation studies of thermal (TBC) and environmental (EBC) barrier coatings of gas turbines by molten CMAS. CMAS minerals usually are carried by the intake air into gas turbines, e.g. in aircraft engines, and their deposits react at high temperatures (1000C) with the coating materials. This causes degradation and accelerated failure of the static and rotating components of the turbine engines. We discuss some preliminary results of the reactions between CMAS and Rare-Earth (RE Y, Yb, Dy, Gd, Nd and Sm) oxide stabilized ZrO2 or HfO2 systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples ( 2.2 mm and 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat treated at 1310 C for 5h. Samples were characterized by differential scanning calorimetry, X-ray diffraction and cross section electron microscopy analysis.

Advanced Exploration Systems Atmosphere Resource Recovery and Environmental Monitoring

NASA Technical Reports Server (NTRS)

Perry, J.; Abney, M.; Conrad, R.; Garber, A.; Howard, D.; Kayatin, M.; Knox, J.; Newton, R.; Parrish, K.; Roman, M.;

Thermal barrier coatings for gas turbine and diesel engines

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Brindley, William J.; Bailey, M. Murray

1989-01-01

The present state of development of thin thermal barrier coatings for aircraft gas turbine engines and thick thermal barrier coatings for truck diesel engines is assessed. Although current thermal barrier coatings are flying in certain gas turbine engines, additional advances will be needed for future engines. Thick thermal barrier coatings for truck diesel engines have advanced to the point where they are being seriously considered for the next generation of engine. Since coatings for truck engines is a young field of inquiry, continued research and development efforts will be required to help bring this technology to commercialization.

A Supplementary Program for Environmental Education, Home Economics, Beginning, Intermediate, Advanced.

ERIC Educational Resources Information Center

Warpinski, Robert

Presented in this teacher's guide for beginning, intermediate, and advanced grades are lesson plans and ideas for integrating home economics (family living, child development, family consumer economics, family housing and interiors, family foods and nutrition, and family clothing and textiles) and environmental education. Each lesson originates…

Environmentally Responsible Aviation N plus 2 Advanced Vehicle Study

NASA Technical Reports Server (NTRS)

Drake, Aaron; Harris, Christopher A.; Komadina, Steven C.; Wang, Donny P.; Bender, Anne M.

2013-01-01

This is the Northrop Grumman final report for the Environmentally Responsible Aviation (ERA) N+2 Advanced Vehicle Study performed for the National Aeronautics and Space Administration (NASA). Northrop Grumman developed advanced vehicle concepts and associated enabling technologies with a high potential for simultaneously achieving significant reductions in emissions, airport area noise, and fuel consumption for transport aircraft entering service in 2025. A Preferred System Concept (PSC) conceptual design has been completed showing a 42% reduction in fuel burn compared to 1998 technology, and noise 75dB below Stage 4 for a 224- passenger, 8,000 nm cruise transport aircraft. Roadmaps have been developed for the necessary technology maturation to support the PSC. A conceptual design for a 55%-scale demonstrator aircraft to reduce development risk for the PSC has been completed.

Advanced Placement Environmental Science and the Curriculum and Community Enterprise for Restoration Science (CCERS) Project in the New York City High School

ERIC Educational Resources Information Center

Birney, Lauren; McNamara, Denise

2018-01-01

This paper explores the issue of social justice through the lens of equitable access to Advanced Placement courses in the City of New York High Schools, with focus on Advanced Placement Environmental Science. A critical component of the Advanced Placement Environmental Science course is the incorporation of environmental fieldwork. The National…

Advances in Permeable Reactive Barrier Technologies

DTIC Science & Technology

2002-08-01

technical methods, such as jetting and hydraulic fracturing , has improved the ability to access deeper aquifers. Table 1 describes the established and...34, Cape Canaveral Air Station, FL. Hydraulic Fracturing 120 A series of wells are installed along the length of the PRB. A vertical fracture is...especially helpful with deep instal- lation methods, such as hydraulic fracturing , where the barrier installed is just a few inches thick. A second, new type

Concrete barrier distress in La Grande, Oregon.

DOT National Transportation Integrated Search

2008-04-01

Several precast concrete barriers in eastern Oregon were noted to be deteriorating at an advanced rate. The ODOT : Research Unit took several core samples from the barriers and conducted analyses. Petrographic evaluations determined : that the strong...

Advanced glycation end-products: modifiable environmental factors profoundly mediate insulin resistance

PubMed Central

Ottum, Mona S.; Mistry, Anahita M.

2015-01-01

Advanced glycation end-products are toxic by-products of metabolism and are also acquired from high-temperature processed foods. They promote oxidative damage to proteins, lipids and nucleotides. Aging and chronic diseases are strongly associated with markers for oxidative stress, especially advanced glycation end-products, and resistance to peripheral insulin-mediated glucose uptake. Modifiable environmental factors including high levels of refined and simple carbohydrate diets, hypercaloric diets and sedentary lifestyles drive endogenous formation of advanced glycation end-products via accumulation of highly reactive glycolysis intermediates and activation of the polyol/aldose reductase pathway producing high intracellular fructose. High advanced glycation end-products overwhelm innate defenses of enzymes and receptor-mediated endocytosis and promote cell damage via the pro-inflammatory and pro-oxidant receptor for advanced glycation end-products. Oxidative stress disturbs cell signal transduction, especially insulin-mediated metabolic responses. Here we review emerging evidence that restriction of dietary advanced glycation end-products significantly reduces total systemic load and insulin resistance in animals and humans in diabetes, polycystic ovary syndrome, healthy populations and dementia. Of clinical importance, this insulin sensitizing effect is independent of physical activity, caloric intake and adiposity level. PMID:26236094

Earth Institute at Columbia University ADVANCE Program: Addressing Needs for Women in Earth and Environmental Sciences

NASA Astrophysics Data System (ADS)

Bell, R. E.; Cane, M.; Mutter, J.; Miller, R.; Pfirman, S.; Laird, J.

2004-12-01

The Earth Institute has received a major NSF ADVANCE grant targeted at increasing the participation and advancement of women scientists and engineers in the Academy through institutional transformation. The Earth Institute at Columbia University includes 9 research institutes including Lamont-Doherty Earth Observatory, Center for Environmental Research and Conservation (CERC), Center for International Earth Science Information Network (CIESIN), International Research Institute (IRI) for Climate Prediction, Earth Engineering Center, NASA-Goddard Institute for Space Studies, Center for Risks and Hazards, Center for Globalization and Sustainable Development, and Center for Global Health and Economic Development and six academic departments including Ecology, Evolution and Environmental Biology (E3B, School of Arts and Sciences), Earth and Environmental Engineering (DEEE, School of Engineering and Applied Sciences), Department of Environmental Health (School of Public Health), Department of Earth and Environmental Sciences (DEES, School of Arts and Sciences), Department of International and Public Affairs (School of International and Policy Affairs), and Barnard College Department of Environmental Science. The Earth Institute at Columbia University's ADVANCE program is based both on a study of the status of women at Columbia and research on the progression of women in science elsewhere. The five major targets of the Columbia ADVANCE program are to (1) change the demographics of the faculty through intelligent hiring practices, (2) provide support to women scientists through difficult life transitions including elder care and adoption or birth of a child, (3) enhance mentoring and networking opportunities, (4) implement transparent promotion procedures and policies, and (5) conduct an institutional self study. The Earth Institute ADVANCE program is unique in that it addresses issues that tend to manifest themselves in the earth and environmental fields, such as extended

2013 Advanced Environmental Health/Advanced Food Technology Standing Review Panel Final Report

NASA Technical Reports Server (NTRS)

Steinberg, Susan

2014-01-01

The 2013 Advanced Environmental Health/Advanced Food Technology (AEH/AFT) Standing Review Panel (from here on referred to as the SRP) participated in a WebEx/teleconference with members of the Space Human Factors and Habitability (SHFH) Element, representatives from the Human Research Program (HRP), and NASA Headquarters on November 22, 2013 (list of participants is in Section IX of this report). The SRP reviewed the updated research plans for the Risk of Adverse Health Effects Due to Alterations in Host-Microorganism Interactions (Host Microbe Risk) and the Risk of Performance Decrement and Crew Illness Due to an Inadequate Food System (Food Risk). The SRP also received a status update on the Risk of Adverse Health Effects of Exposure to Dust and Volatiles during Exploration of Celestial Bodies (Dust Risk). Overall, the SRP was impressed with the strong research plans presented by the scientists and staff associated with the SHFH Element. The SRP also thought that the updated research plans were thorough, well organized, and presented in a comprehensive manner. The SRP agrees with the changes made to the Host Microbe Risk and Food Risk portfolios and thinks that the targets for Gap closure are appropriate.

Using Community Advisory Boards to Reduce Environmental Barriers to Health in American Indian Communities, Wisconsin, 2007–2012

PubMed Central

Scott, Jamie R.; Prince, Ron; Williamson, Amy

2014-01-01

Background American Indian communities have a high prevalence of chronic diseases including diabetes, obesity, cardiovascular disease, and cancer. Innovative community-based approaches are needed to identify, prioritize, and create sustainable interventions to reduce environmental barriers to healthy lifestyles and ultimately improve health. Community Context Healthy Children, Strong Families was a family-based and community-based intervention to increase healthy lifestyles on Wisconsin American Indian reservations. This intervention arose from a long-standing partnership between University of Wisconsin researchers and 3 of these American Indian communities. Methods In each community, community advisory boards (CABs) were established by the residents and university partners. CAB meetings were open and held at various times and locations to increase member participation. CABs featured continual, snowball recruitment; internal and external expert consultation; and coordination with standing tribal committees. Meetings initially focused on understanding community supports for and barriers to healthy lifestyles but quickly turned toward community action for change. Outcome CAB interventions decreased environmental barriers to health at each site and improved options for healthy lifestyle choices. Over 5 years, 71 CAB meetings occurred with a total of 1,070 participants. Successful CAB interventions included planting community gardens and an apple orchard, conducting gardening and canning workshops, instituting food-related policies and dog control regulations, building an environmentally friendly playground, and providing access to recreational facilities. The CABs are now self-sustaining. Interpretation CABs can be highly effective action teams capable of improving community environments. Our experience shows that academic researchers can partner with community residents to generate programs and policies that will expand access to local food, increase people�

Barriers to NP Practice that Impact Healthcare Redesign.

PubMed

Hain, Debra; Fleck, Laureen M

2014-05-31

As healthcare reform evolves, nurse practitioners (NP) will play key roles in improving health outcomes of diverse populations. According to the Institute of Medicine (IOM) 2011 report, The Future of Nursing: Leading Change Advancing Health, nurses should be change advocates by caring for populations within complex healthcare systems. The IOM reports asserts, "advanced practice registered nurses (APRNs) should be able to practice to the fullest extent of their education and training" (IOM, 2011, s8). However, existing barriers in the healthcare arena limit APRN practice. This article will discuss some of these barriers and provide suggestions for possible ways to decrease the barriers.

Advancing Environmental Flow Science: Developing Frameworks for Altered Landscapes and Integrating Efforts Across Disciplines

NASA Astrophysics Data System (ADS)

Brewer, Shannon K.; McManamay, Ryan A.; Miller, Andrew D.; Mollenhauer, Robert; Worthington, Thomas A.; Arsuffi, Tom

2016-08-01

Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches to address streamflow needs in highly modified landscapes where historic flows do not provide reasonable comparisons, (2) integrating water quality needs where interactions are apparent with quantity but not necessarily the proximate factor of the ecological degradation, especially as frequency and magnitudes of inflows to bays and estuaries, (3) providing a better understanding of the ecological needs of native species to offset the often unintended consequences of benefiting non-native species or their impact on flows, (4) improving our understanding of the non-use economic value to balance consumptive economic values, and (5) increasing our understanding of the stakeholder socioeconomic spatial distribution of attitudes and perceptions across the landscape. Environmental flow science is still an emerging interdisciplinary field and by integrating socioeconomic disciplines and developing new frameworks to accommodate our altered landscapes, we should help advance environmental flow science and likely increase successful implementation of flow standards.

Advancing environmental flow science: Developing frameworks for altered landscapes and integrating efforts across disciplines.

USGS Publications Warehouse

Brewer, Shannon K.; McManamay, Ryan A.; Miller, Andrew D.; Mollenhauer, Robert; Worthington, Thomas A.; Arsuffi, Tom

2016-01-01

Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches to address streamflow needs in highly modified landscapes where historic flows do not provide reasonable comparisons, (2) integrating water quality needs where interactions are apparent with quantity but not necessarily the proximate factor of the ecological degradation, especially as frequency and magnitudes of inflows to bays and estuaries, (3) providing a better understanding of the ecological needs of native species to offset the often unintended consequences of benefiting non-native species or their impact on flows, (4) improving our understanding of the non-use economic value to balance consumptive economic values, and (5) increasing our understanding of the stakeholder socioeconomic spatial distribution of attitudes and perceptions across the landscape. Environmental flow science is still an emerging interdisciplinary field and by integrating socioeconomic disciplines and developing new frameworks to accommodate our altered landscapes, we should help advance environmental flow science and likely increase successful implementation of flow standards.

Advancing Environmental Flow Science: Developing Frameworks for Altered Landscapes and Integrating Efforts Across Disciplines.

PubMed

Brewer, Shannon K; McManamay, Ryan A; Miller, Andrew D; Mollenhauer, Robert; Worthington, Thomas A; Arsuffi, Tom

2016-08-01

Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches to address streamflow needs in highly modified landscapes where historic flows do not provide reasonable comparisons, (2) integrating water quality needs where interactions are apparent with quantity but not necessarily the proximate factor of the ecological degradation, especially as frequency and magnitudes of inflows to bays and estuaries, (3) providing a better understanding of the ecological needs of native species to offset the often unintended consequences of benefiting non-native species or their impact on flows, (4) improving our understanding of the non-use economic value to balance consumptive economic values, and (5) increasing our understanding of the stakeholder socioeconomic spatial distribution of attitudes and perceptions across the landscape. Environmental flow science is still an emerging interdisciplinary field and by integrating socioeconomic disciplines and developing new frameworks to accommodate our altered landscapes, we should help advance environmental flow science and likely increase successful implementation of flow standards.

Barriers to Professional Advancement among Female Managers.

ERIC Educational Resources Information Center

O'Leary, Virginia E.

It appears that there is nothing inherently associated with femaleness which should preclude the ascendence of women into management positions. However, barriers do exist and they stem from such factors as societal sex-role stereotypes, attitudes toward women in management, attitudes toward female competence, and the prevalence of the male…

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

PubMed

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

2014-05-06

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

Kinetic Monte Carlo Simulations of Oxygen Diffusion in Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

Good, Brian S.

2017-01-01

Ceramic Matrix Composite (CMC) materials are of interest for use in next-generation turbine engine components, offering a number of significant advantages, including reduced weight and high operating temperatures. However, in the hot environment in which such components operate, the presence of water vapor can lead to corrosion and recession, limiting the useful life of the components. Such degradation can be reduced through the use of Environmental Barrier Coatings (EBCs) that limit the amount of oxygen and water vapor reaching the component. Candidate EBC materials include Yttrium and Ytterbium silicates. In this work we present results of kinetic Monte Carlo (kMC) simulations of oxygen diffusion, via the vacancy mechanism, in Yttrium and Ytterbium disilicates, along with a brief discussion of interstitial diffusion.

Investigation of the Mechanical Performance of Compliant Thermal Barriers

NASA Technical Reports Server (NTRS)

DeMange, Jeffrey J.; Bott, Robert J.; Dunlap, Patrick H.

2011-01-01

Compliant thermal barriers play a pivotal role in the thermal protection systems of advanced aerospace vehicles. Both the thermal properties and mechanical performance of these barriers are critical in determining their successful implementation. Due to the custom nature of many thermal barriers, designers of advanced spacecraft have little guidance as to the design, selection, and implementation of these elements. As part of an effort to develop a more fundamental understanding of the interrelationship between thermal barrier design and performance, mechanical testing of thermal barriers was conducted. Two different types of thermal barriers with several core insulation density levels ranging from 62 to 141 kg/cu m were investigated. Room-temperature compression tests were conducted on samples to determine load performance and assess thermal barrier resiliency. Results showed that the loading behavior of these thermal barriers was similar to other porous, low-density, compliant materials, such as elastomeric foams. Additionally, the insulation density level had a significant non-linear impact on the stiffness and peak loads of the thermal barriers. In contrast, neither the thermal barrier type nor the level of insulation density significantly influenced the room-temperature resiliency of the samples.

Advanced Environmental Monitoring and Control Program: Technology Development Requirements

NASA Technical Reports Server (NTRS)

Jan, Darrell (Editor); Seshan, Panchalam (Editor); Ganapathi, Gani (Editor); Schmidt, Gregory (Editor); Doarn, Charles (Editor)

1996-01-01

Human missions in space, from the International Space Station on towards potential human exploration of the moon, Mars and beyond into the solar system, will require advanced systems to maintain an environment that supports human life. These systems will have to recycle air and water for many months or years at a time, and avoid harmful chemical or microbial contamination. NASA's Advanced Environmental Monitoring and Control program has the mission of providing future spacecraft with advanced, integrated networks of microminiaturized sensors to accurately determine and control the physical, chemical and biological environment of the crew living areas. This document sets out the current state of knowledge for requirements for monitoring the crew environment, based on (1) crew health, and (2) life support monitoring systems. Both areas are updated continuously through research and space mission experience. The technologies developed must meet the needs of future life support systems and of crew health monitoring. These technologies must be inexpensive and lightweight, and use few resources. Using these requirements to continue to push the state of the art in miniaturized sensor and control systems will produce revolutionary technologies to enable detailed knowledge of the crew environment.

Advanced Computational Framework for Environmental Management ZEM, Version 1.x

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vesselinov, Velimir V.; O'Malley, Daniel; Pandey, Sachin

2016-11-04

Typically environmental management problems require analysis of large and complex data sets originating from concurrent data streams with different data collection frequencies and pedigree. These big data sets require on-the-fly integration into a series of models with different complexity for various types of model analyses where the data are applied as soft and hard model constraints. This is needed to provide fast iterative model analyses based on the latest available data to guide decision-making. Furthermore, the data and model are associated with uncertainties. The uncertainties are probabilistic (e.g. measurement errors) and non-probabilistic (unknowns, e.g. alternative conceptual models characterizing site conditions).more » To address all of these issues, we have developed an integrated framework for real-time data and model analyses for environmental decision-making called ZEM. The framework allows for seamless and on-the-fly integration of data and modeling results for robust and scientifically-defensible decision-making applying advanced decision analyses tools such as Bayesian- Information-Gap Decision Theory (BIG-DT). The framework also includes advanced methods for optimization that are capable of dealing with a large number of unknown model parameters, and surrogate (reduced order) modeling capabilities based on support vector regression techniques. The framework is coded in Julia, a state-of-the-art high-performance programing language (http://julialang.org). The ZEM framework is open-source and can be applied to any environmental management site. The framework will be open-source and released under GPL V3 license.« less

Zircon-Based Ceramics Composite Coating for Environmental Barrier Coating

NASA Astrophysics Data System (ADS)

Suzuki, M.; Sodeoka, S.; Inoue, T.

2008-09-01

Studies on plasma spraying of zircon (ZrSiO4) have been carried out by the authors as one of the candidates for an environmental barrier coating (EBC) application, and had reported that substrate temperature is one of the most important factors to obtain crack-free and highly adhesive coating. In this study, several amounts of yttria were added to zircon powder, and the effect of the yttria addition on the structure and properties of the coatings were evaluated to improve the stability of the zircon coating structure at elevated temperature. The coatings obtained were composed of yttria-stabilized zirconia (YSZ), glassy silica, whereas the one prepared from monolithic zircon powder was composed of the metastable high temperature tetragonal phase of zirconia and glassy silica. After the heat treatment over 1200 °C, silica and zirconia formed zircon in all coatings. However, coatings with higher amounts of yttria exhibited lower amounts of zircon. This resulted in the less open porosity of the coating at elevated temperature. These yttria-added coatings also showed good adhesion even after the heat treatment, while monolithic zircon coating pealed off.

An environmental scan of advance care planning decision AIDS for patients undergoing major surgery: a study protocol.

PubMed

Aslakson, Rebecca A; Schuster, Anne L R; Miller, Judith; Weiss, Matthew; Volandes, Angelo E; Bridges, John F P

2014-01-01

Patients who undergo major surgery are at risk for perioperative morbidity and mortality. It would be appropriate to initiate advance care planning with patients prior to surgery, but surgeons may experience difficulty initiating such conversations. Rather than focus on changing clinician behavior, advance care planning decision aids can be an innovative vehicle to motivate advance care planning among surgical patients and their families. The purpose of this paper is to describe a study protocol for conducting an environmental scan concerning advance care planning decision aids that may be relevant to patients undergoing high-risk surgery. This study will gather information from written or verbal data sources that incorporate professional and lay perspectives: a systematic review, a grey literature review, key informant interviews, and patient and family engagement. It is envisioned that this study will generate three outcomes: a synthesis of current evidence, a summary of gaps in knowledge, and a taxonomy of existing advance care planning decision aids. This environmental scan will demonstrate principles of patient-centered outcomes research, and it will exemplify a pioneering approach for reviewing complex interventions. Anticipated limitations are that information will be gathered from a small sample of patients and families, and that potentially relevant information could also be missing from the environmental scan due to the inclusion/exclusion criteria. Outcomes from the environmental scan will inform future patient-centered research to develop and evaluate a new decision aid.

A methodology for the environmental assessment of advanced coal extraction systems

NASA Technical Reports Server (NTRS)

Sullivan, P. J.; Hutchinson, C. F.; Makihara, J.; Evensizer, J.

1980-01-01

Procedures developed to identify and assess potential environment impacts of advanced mining technology as it moves from a generic concept to a more systems definition are described. Two levels of assessment are defined in terms of the design stage of the technology being evaluated. The first level of analysis is appropriate to a conceptual design. At this level it is assumed that each mining process has known and potential environmental impacts that are generic to each mining activity. By using this assumption, potential environmental impacts can be identified for new mining systems. When two or more systems have been assessed, they can be evaluated comparing potential environmental impacts. At the preliminary stage of design, a systems performance can be assessed again with more precision. At this level of systems definition, potential environmental impacts can be analyzed and their significane determined in a manner to facilitate comparisons between systems. At each level of analysis, suggestions calculated to help the designer mitigate potentially harmful impacts are provided.

Advancing Environmental Flow Science: Developing Frameworks for Altered Landscapes and Integrating Efforts Across Disciplines

DOE PAGES

Brewer, Shannon; McManamay, Ryan A.; Miller, Andrew D.; ...

2016-05-13

Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches to address streamflow needs in highly modified landscapes where historic flows do not provide reasonable comparisons, (2) integrating water quality needs where interactions are apparent with quantity but not necessarily the proximate factor of the ecological degradation, especially as frequency and magnitudes of inflows to bays and estuaries, (3) providing a bettermore » understanding of the ecological needs of native species to offset the often unintended consequences of benefiting non-native species or their impact on flows, (4) improving our understanding of the non-use economic value to balance consumptive economic values, and (5) increasing our understanding of the stakeholder socioeconomic spatial distribution of attitudes and perceptions across the landscape. Environmental flow science is still an emerging interdisciplinary field and by integrating socioeconomic disciplines and developing new frameworks to accommodate our altered landscapes, we should help advance environmental flow science and likely increase successful implementation of flow standards.« less

Advancing Environmental Flow Science: Developing Frameworks for Altered Landscapes and Integrating Efforts Across Disciplines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brewer, Shannon; McManamay, Ryan A.; Miller, Andrew D.

Environmental flows represent a legal mechanism to balance existing and future water uses and sustain non-use values. Here, we identify current challenges, provide examples where they are important, and suggest research advances that would benefit environmental flow science. Specifically, environmental flow science would benefit by (1) developing approaches to address streamflow needs in highly modified landscapes where historic flows do not provide reasonable comparisons, (2) integrating water quality needs where interactions are apparent with quantity but not necessarily the proximate factor of the ecological degradation, especially as frequency and magnitudes of inflows to bays and estuaries, (3) providing a bettermore » understanding of the ecological needs of native species to offset the often unintended consequences of benefiting non-native species or their impact on flows, (4) improving our understanding of the non-use economic value to balance consumptive economic values, and (5) increasing our understanding of the stakeholder socioeconomic spatial distribution of attitudes and perceptions across the landscape. Environmental flow science is still an emerging interdisciplinary field and by integrating socioeconomic disciplines and developing new frameworks to accommodate our altered landscapes, we should help advance environmental flow science and likely increase successful implementation of flow standards.« less

Environmental Barrier Coatings Having a YSZ Top Coat

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Gray, Hugh (Technical Monitor)

2002-01-01

Environmental barrier coatings (EBCs) with a Si bond coat, a yttria-stabilized zirconia (YSZ) top coat, and various intermediate coats were investigated. EBCs were processed by atmospheric pressure plasma spraying. The EBC durability was determined by thermal cycling tests in water vapor at 1300 C and 1400 C, and in air at 1400 C and 1500 C. EBCs with a mullite (3Al2O3 (dot) 2SiO2) + BSAS (1 - xBaO (dot) xSrO (dot) Al2O3 (dot) 2SiO2) intermediate coat were more durable than EBCs with a mullite intermediate coat, while EBCs with a mullite/BSAS duplex intermediate coat resulted in inferior durability. The improvement with a mullite + BSAS intermediate coat was attributed to enhanced compliance of the intermediate coat due to the addition of a low modulus BSAS second phase. Mullite + BSAS/YSZ and BSAS/YSZ interfaces produced a low melting (less than 1400 C) reaction product, which is expected to degrade the EBC performance by increasing the thermal conductivity. EBCs with a mullite + BSAS / graded mullite + YSZ intermediate coat showed the best durability among the EBCs investigated in this study. This improvement was attributed to diffused CTE (Coefficient of Thermal Expansion) mismatch stress and improved chemical stability due to the compositionally graded mullite+YSZ layer.

Mechanical Properties of Air Plasma Sprayed Environmental Barrier Coating (EBC) Materials

NASA Technical Reports Server (NTRS)

Richards, Bradley; Zhu, Dongming; Ghosn, Louis; Wadley, Haydn

2015-01-01

Development work in Environmental Barrier Coatings (EBCs) for Ceramic Matrix Composites (CMCs) has focused considerably on the identification of materials systems and coating architectures to meet application needs. The evolution of these systems has occurred so quickly that modeling efforts and requisite data for modeling lag considerably behind development. Materials property data exists for many systems in the bulk form, but the effects of deposition on the critical properties of strength and fracture behavior are not well studied. We have plasma sprayed bulk samples of baseline EBC materials (silicon, ytterbium disilicate) and tested the mechanical properties of these materials to elicit differences in strength and toughness. We have also endeavored to assess the mixed-mode fracture resistance, Gc, of silicon in a baseline EBC applied to SiCSiC CMC via four point bend test. These results are compared to previously determined properties of the comparable bulk material.

Barriers and facilitators of sports in Dutch Paralympic athletes: An explorative study.

PubMed

Jaarsma, E A; Geertzen, J H B; de Jong, R; Dijkstra, P U; Dekker, R

2014-10-01

The purpose of this study was to gain insight in barriers and facilitators of sports in paralympic athletes. An online questionnaire was distributed through the Netherlands Olympic Committee and National Sports Confederation to determine personal and environmental barriers and facilitators of sports participation. The International Classification of Functioning, Disability and Health model and theory of planned behavior were used to respectively categorize the results in environmental and personal factors, and attitude, subjective norm and perceived behavioral control. Seventy-six Dutch Paralympic athletes completed the questionnaire (51% response rate). Barriers and facilitators experienced by ambulant and wheelchair athletes were compared. Most frequently mentioned personal barrier was dependency of others (22%), while most frequently mentioned environmental barrier was lack of sports facilities (30%). Wheelchair athletes mentioned more barriers (median = 3, interquartile range: 0.5-6), than ambulant athletes (median = 1.0,interquartile range:0.0-3.0, P = 0.023). One-third of the athletes did not experience any barriers. Most frequently mentioned personal facilitators to initiate sports participation were fun (78%), health (61%), and competition (53%). Most frequently mentioned environmental facilitator was social support (40%). This study indicated that barriers of sport were mostly environmental, while facilitators were usually personal factors. Attitude and subjective norm were considered the most important components for intention to participation in sports. The facilitators outweighed the barriers and kept the athletes being active in sports. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Environmental barrier material for organic light emitting device and method of making

DOEpatents

Graff, Gordon L [West Richland, WA; Gross, Mark E [Pasco, WA; Affinito, John D [Kennewick, WA; Shi, Ming-Kun [Richland, WA; Hall, Michael [West Richland, WA; Mast, Eric [Richland, WA

2003-02-18

An encapsulated organic light emitting device. The device includes a first barrier stack comprising at least one first barrier layer and at least one first polymer layer. There is an organic light emitting layer stack adjacent to the first barrier stack. A second barrier stack is adjacent to the organic light emitting layer stack. The second barrier stack has at least one second barrier layer and at least one second polymer layer. A method of making the encapsulated organic light emitting device is also provided.

[Advance in studies on food allergy mechanism based on gut barrier].

PubMed

Wang, Juan-hong; Li, Huan-zhou; Li, Meng; Pan, Su-hua

2015-04-01

Food allergies, as a type of adverse immune-mediated reactions to ingested food proteins, have become a serious public health issue that harms children and adults health, with increasing incidence year by year. However, without effective therapy for food allergies, doctors-have mostly advised to avoid allergens and provided symptomatic treatment. According to the findings of many studies, allergic diseases are correlated with intestinal barrier function injury, as evidenced by the significant increase in the intestinal permeability among patients with food allergies. In this paper, recent studies on correlations between food allergies and intestinal barrier functions, intestinal barrier function injury mechanisms of allergic foods and food allergy intervention strategies based on intestinal barrier functions were summarized to provide reference for laboratory researches and clinical treatment of food allergic diseases.

The NIEHS Environmental Health Sciences Data Resource Portal: placing advanced technologies in service to vulnerable communities.

PubMed

Pezzoli, Keith; Tukey, Robert; Sarabia, Hiram; Zaslavsky, Ilya; Miranda, Marie Lynn; Suk, William A; Lin, Abel; Ellisman, Mark

2007-04-01

Two devastating hurricanes ripped across the Gulf Coast of the United States during 2005. The effects of Hurricane Katrina were especially severe: the human and environmental health impacts on New Orleans, Louisiana, and other Gulf Coast communities will be felt for decades to come. The Federal Emergency Management Agency (FEMA) estimates that Katrina's destruction disrupted the lives of roughly 650,000 Americans. Over 1,300 people died. The projected economic costs for recovery and reconstruction are likely to exceed $125 billion. The NIEHS (National Institute of Environmental Health Sciences) Portal aims to provide decision makers with the data, information, and the tools they need to a) monitor human and environmental health impacts of disasters; b) assess and reduce human exposures to contaminants; and c) develop science-based remediation, rebuilding, and repopulation strategies. The NIEHS Portal combines advances in geographic information systems (GIS), data mining/integration, and visualization technologies through new forms of grid-based (distributed, web-accessible) cyberinfrastructure. The scale and complexity of the problems presented by Hurricane Katrina made it evident that no stakeholder alone could tackle them and that there is a need for greater collaboration. The NIEHS Portal provides a collaboration-enabling, information-laden base necessary to respond to environmental health concerns in the Gulf Coast region while advancing integrative multidisciplinary research. The NIEHS Portal is poised to serve as a national resource to track environmental hazards following natural and man-made disasters, focus medical and environmental response and recovery resources in areas of greatest need, and function as a test bed for technologies that will help advance environmental health sciences research into the modern scientific and computing era.

Crossing the Blood-Brain Barrier: Recent Advances in Drug Delivery to the Brain.

PubMed

Patel, Mayur M; Patel, Bhoomika M

2017-02-01

CNS disorders are on the rise despite advancements in our understanding of their pathophysiological mechanisms. A major hurdle to the treatment of these disorders is the blood-brain barrier (BBB), which serves as an arduous janitor to protect the brain. Many drugs are being discovered for CNS disorders, which, however fail to enter the market because of their inability to cross the BBB. This is a pronounced challenge for the pharmaceutical fraternity. Hence, in addition to the discovery of novel entities and drug candidates, scientists are also developing new formulations of existing drugs for brain targeting. Several approaches have been investigated to allow therapeutics to cross the BBB. As the molecular structure of the BBB is better elucidated, several key approaches for brain targeting include physiological transport mechanisms such as adsorptive-mediated transcytosis, inhibition of active efflux pumps, receptor-mediated transport, cell-mediated endocytosis, and the use of peptide vectors. Drug-delivery approaches comprise delivery from microspheres, biodegradable wafers, and colloidal drug-carrier systems (e.g., liposomes, nanoparticles, nanogels, dendrimers, micelles, nanoemulsions, polymersomes, exosomes, and quantum dots). The current review discusses the latest advancements in these approaches, with a major focus on articles published in 2015 and 2016. In addition, we also cover the alternative delivery routes, such as intranasal and convection-enhanced diffusion methods, and disruption of the BBB for brain targeting.

The blood-brain barrier: an engineering perspective

PubMed Central

Wong, Andrew D.; Ye, Mao; Levy, Amanda F.; Rothstein, Jeffrey D.; Bergles, Dwight E.; Searson, Peter C.

2013-01-01

It has been more than 100 years since Paul Ehrlich reported that various water-soluble dyes injected into the circulation did not enter the brain. Since Ehrlich's first experiments, only a small number of molecules, such as alcohol and caffeine have been found to cross the blood-brain barrier, and this selective permeability remains the major roadblock to treatment of many central nervous system diseases. At the same time, many central nervous system diseases are associated with disruption of the blood-brain barrier that can lead to changes in permeability, modulation of immune cell transport, and trafficking of pathogens into the brain. Therefore, advances in our understanding of the structure and function of the blood-brain barrier are key to developing effective treatments for a wide range of central nervous system diseases. Over the past 10 years it has become recognized that the blood-brain barrier is a complex, dynamic system that involves biomechanical and biochemical signaling between the vascular system and the brain. Here we reconstruct the structure, function, and transport properties of the blood-brain barrier from an engineering perspective. New insight into the physics of the blood-brain barrier could ultimately lead to clinical advances in the treatment of central nervous system diseases. PMID:24009582

PERMEABLE REACTIVE BARRIER TECHNOLOGIES FOR CONTAMINANT REMEDIATION

EPA Science Inventory

Environmental scientists are generally familiar with the concept of barriers for restricting the movement of contaminant plumes in ground water. Such barriers are typically constructed of highly impermeable emplacements of materials such as grouts, slurries, or sheet pilings to ...

Development and Psychometric Properties of a Survey to Assess Barriers to Implementing Advance Care Planning in Primary Care.

PubMed

Howard, Michelle; Day, Andrew G; Bernard, Carrie; Tan, Amy; You, John; Klein, Doug; Heyland, Daren K

2018-01-01

Valid and reliable measurement of barriers to advance care planning (ACP) in health care settings can inform the design of robust interventions. This article describes the development and psychometric evaluation of an instrument to measure the presence and magnitude of perceived barriers to ACP discussion with patients from the perspective of family physicians. A questionnaire was designed through literature review and expert input, asking family physicians to rate the importance of barriers (0 = not at all a barrier and 6 = an extreme amount) to ACP discussions with patients and administered to 117 physicians. Floor effects and missing data patterns were examined. Item-by-item correlations were examined using Pearson correlation. Exploratory factor analysis was conducted (iterated principle factor analysis with oblique rotation), internal consistency (Cronbach's alpha) overall and within factors was calculated, and construct validity was evaluated by calculating three correlations with related questions that were specified a priori. The questionnaire included 31 questions in three domains relating to the clinician, patient/family and system or external factors. No items were removed due to missing data, floor effects, or high correlation with another item. A solution of three factors accounted for 71% of variance. One item was removed because it did not load strongly on any factor. All other items except one remained in the original domain in the questionnaire. Cronbach's alpha for the three factors ranged from 0.84 to 0.90. Two of three a priori correlations with related questions were statistically significant. This questionnaire to assess barriers to ACP discussion from the perspective of family physicians demonstrates preliminary evidence of reliability and validity. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Upper Temperature Limit of Environmental Barrier Coatings Based on Mullite and BSAS

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis S.; Eldridge, Jeffrey I.; Zhu, Dongming; Bansal, Narottam P.; Miller, Robert A.; Robinson, Raymond C.

2002-01-01

Current state-of-the-art environmental barrier coatings (EBCs) for Si-based ceramics consist of three layers: a silicon bond coat, an intermediate mullite (3Al2O3-2SiO2) or mullite + BSAS (1-xBaO-xSrO-Al2O3-2SiO2) layer, and a BSAS top coat. Areas of concern for long-term durability are environmental durability, chemical compatibility, silica volatility, phase stability, and thermal conductivity. Variants of this family of EBCs were applied to monolithic SiC and melt infiltrated SiC/SiC composites. Reaction between BSAS and silica results in low melting (approx. 1300 C) glasses at T > 1400 C, which can cause the spallation of the EBC. At temperatures greater than 1400 C, the BSAS top coat also degrades by formation of a porous structure, and it suffers significant recession via silica volatilization in water vapor-containing atmospheres. All of these degradation mechanisms can be EBC life-limiting factors. BSAS undergoes a very sluggish phase transformation (hexagonal celsian to monoclinic celsian), the implications of which are not fully understood at this point. There was evidence of rapid sintering at temperatures as low as 1300 C, as inferred from the sharp increase in thermal conductivity.

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

NASA Technical Reports Server (NTRS)

Amos, D. J.

1977-01-01

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Language and style: A barrier to neurosurgical research and advancement in Latin America

PubMed Central

Ashfaq, Adeel; Lazareff, Jorge

2017-01-01

Background: The neurosurgical burden in Latin America is understudied and likely underestimated, thus it is imperative to improve quality, training, and delivery of neurosurgical care. A significant aspect of this endeavor is for Latin America to become an integral aspect of the global neurosurgical community, however, there is a paucity of ideology and literature coming from Central and South America. We sought to explore neurosurgical dialogue originating from Latin America as well as barriers to the advancement of neurosurgery in this region. Methods: We conducted a systematic literature review exploring research originating in Latin America in three international neurosurgical journals – Journal of Neurosurgery, Surgical Neurology International, and World Neurosurgery. We utilized PubMed search algorithms to identify articles. Inclusion criteria included publication within the three aforementioned journals, author affiliation with Latin American institutions, and publication within the specified time frame of January 2014 to July 2017. Results: There were 7469 articles identified that met the search criteria. Of these 7469 articles, 326 (4.4%) were from Latin American nations. Conclusion: Our data suggests a relatively low percentage of neurosurgical research originating from Latin America, suggesting a significant lack of participation in the global neurosurgical community. Barriers to global scientific communication include language, rhetorical style, culture, history, biases, funding, and governmental support. Despite challenges, Latin America is making strides towards improvement including the development of neurosurgical societies, as well as international collaborative training and research programs. We consider our report to be a valid initiation of discussion of the broader issue of neurosurgical communication. PMID:29404195

High Temperature Degradation of Advanced Thermal and Environmental Barrier Coatings (TEBCs) by CaO-MgO-Al2O3-SiO2 (CMAS)

NASA Technical Reports Server (NTRS)

Costa, Gustavo; Zhu, Dongming

2017-01-01

There is increasing interest in the degradation studies of thermal and environmental barrier coatings (TEBCs) of gas turbines by molten CaO-MgO-Al2O3-SiO2 (CMAS). CMAS minerals are usually referred as silica-containing sand dust and volcano ash materials that are carried by the intake air into gas turbines, e.g. aircraft engines. The low-melting deposits react at high temperatures (1000C) with the coating materials. This causes degradation and accelerated coating failure of the static and rotating components of the turbine engines. We discuss some preliminary results of the reactions between CMAS and Rare-Earth (RE Y, Yb, Dy, Gd, Nd and Sm) oxide stabilized ZrO2 or HfO2 systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples (outer diameter 4.7 mm, wall thickness 0.76 mm and 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat- treated at 1310 C for 5h. Samples were characterized by differential scanning calorimetry, X-ray diffraction and cross section electron microscopy analysis.

Sports participation after rehabilitation: Barriers and facilitators.

PubMed

Jaarsma, Eva A; Dekker, Rienk; Geertzen, Jan H B; Dijkstra, Pieter U

2016-01-01

To analyse barriers to, and facilitators of, sports participation among people with physical disabilities after rehabilitation and to compare differences between inactive and active participants regarding these experienced barriers and facilitators. Participants were 1,223 adults (mean age 51.6 years, standard deviation 15.1 years) treated in the Rehabilitation Centre of the University Medical Center Groningen, who completed a questionnaire. The questionnaire consisted of a self-constructed questionnaire regarding barriers and facilitators. Fifty-eight percent of the participants were active in sports after their rehabilitation. Younger age and a higher level of education were positively associated with sports participation, whereas using assistive devices and experiencing environmental barriers were negatively associated. Facilitators of sports participation were health, fun and increasing physical strength, and advice from rehabilitation professionals. Rehabilitation professionals should emphasize the health benefits of, and enjoyment from, sports participation for people with physical disabilities. They should repeatedly remind people with physical disabilities to stay/become active after completing their rehabilitation programme. Rehabilitation professionals should also provide information about strategies to reduce environmental barriers to sports participation, which could help people using assistive devices to overcome these barriers.

The NIEHS Environmental Health Sciences Data Resource Portal: Placing Advanced Technologies in Service to Vulnerable Communities

PubMed Central

Pezzoli, Keith; Tukey, Robert; Sarabia, Hiram; Zaslavsky, Ilya; Miranda, Marie Lynn; Suk, William A.; Lin, Abel; Ellisman, Mark

2007-01-01

Background Two devastating hurricanes ripped across the Gulf Coast of the United States during 2005. The effects of Hurricane Katrina were especially severe: The human and environmental health impacts on New Orleans, Louisiana, and other Gulf Coast communities will be felt for decades to come. The Federal Emergency Management Agency (FEMA) estimates that Katrina’s destruction disrupted the lives of roughly 650,000 Americans. Over 1,300 people died. The projected economic costs for recovery and reconstruction are likely to exceed $125 billion. Objectives The NIEHS (National Institute of Environmental Health Sciences) Portal aims to provide decision makers with the data, information, and the tools they need to a) monitor human and environmental health impacts of disasters; b) assess and reduce human exposures to contaminants; and c) develop science-based remediation, rebuilding, and repopulation strategies. Methods The NIEHS Portal combines advances in geographic information systems (GIS), data mining/integration, and visualization technologies through new forms of grid-based (distributed, web-accessible) cyberinfrastructure. Results The scale and complexity of the problems presented by Hurricane Katrina made it evident that no stakeholder alone could tackle them and that there is a need for greater collaboration. The NIEHS Portal provides a collaboration-enabling, information-laden base necessary to respond to environmental health concerns in the Gulf Coast region while advancing integrative multidisciplinary research. Conclusions The NIEHS Portal is poised to serve as a national resource to track environmental hazards following natural and man-made disasters, focus medical and environmental response and recovery resources in areas of greatest need, and function as a test bed for technologies that will help advance environmental health sciences research into the modern scientific and computing era. PMID:17450225

Optimizing Barrier Removal to Restore Connectivity in Utah's Weber Basin

NASA Astrophysics Data System (ADS)

Kraft, M.; Null, S. E.

2016-12-01

Instream barriers, such as dams, culverts and diversions are economically important for water supply, but negatively affect river ecosystems and disrupt hydrologic processes. Removal of uneconomical and aging in-stream barriers to improve habitat connectivity is increasingly used to restore river connectivity. Most past barrier removal projects focused on individual barriers using a score-and-rank technique, ignoring cumulative change from multiple, spatially-connected barrier removals. Similarly, most water supply models optimize either human water use or aquatic connectivity, failing to holistically represent human and environmental benefits. In this study, a dual objective optimization model identified in-stream barriers that impede aquatic habitat connectivity for trout, using streamflow, temperature, and channel gradient as indicators of aquatic habitat suitability. Water scarcity costs are minimized using agricultural and urban economic penalty functions to incorporate water supply benefits and a budget monetizes costs of removing small barriers like culverts and road crossings. The optimization model developed is applied to a case study in Utah's Weber basin to prioritize removal of the most environmentally harmful barriers, while maintaining human water uses. The dual objective solution basis was developed to quantify and graphically visualize tradeoffs between connected quality-weighted habitat for Bonneville cutthroat trout and economic water uses. Modeled results include a spectrum of barrier removal alternatives based on budget and quality-weighted reconnected habitat that can be communicated with local stakeholders. This research will help prioritize barrier removals and future restoration decisions. The modeling approach expands current barrier removal optimization methods by explicitly including economic and environmental water uses.

Organizational barriers

Treesearch

Kenneth S. Blonski

1995-01-01

One of the traditional roles that prescribed fire has played in the fire management arena is reduction of hazardous fuel buildups under controlled, well-defined environmental conditions. However, our ability to use this tool effectively is blocked by many barriers. The preceding panel discussion about the causes of limited success in implementing prescribed burning...

Barriers and Facilitators to Career Advancement by Top-Level, Entry-Level and Non-Administrative Women in Public School Districts: A Mixed Methods Study

ERIC Educational Resources Information Center

Ahmed, Eman Ibrahim El-Desouki

2011-01-01

The purpose of this study was to investigate the barriers and facilitators to career advancement among women administrators occupying top-level positions, those occupying entry-level positions and those in non-administrative positions in both rural and urban public school districts in central Pennsylvania. The need to increase the awareness of the…

[Interrelationships between soil fauna and soil environmental factors in China: research advance].

PubMed

Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

2010-09-01

Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.

2015 Advanced Environmental Health/Advanced Food Technology Standing Review Panel

NASA Technical Reports Server (NTRS)

Steinberg, Susan

2015-01-01

The 2015 Advanced Environmental Health/Advanced Food Technology (AEH/AFT) Standing Review Panel (from here on referred to as the SRP) met for a site visit in Houston, TX on December 14 - 15, 2015. The SRP met with representatives from the Space Human Factors and Habitability (SHFH) Element and members of the Human Research Program (HRP) to review the updated research plans for the Risk of Adverse Health Effects Due to Host-Microorganism Interactions (MicroHost Risk) and the Risk of Performance Decrement and Crew Illness due to an Inadequate Food System (Food Risk). During the meeting, the SRP also met with the vehicle engineers to discuss possible food storage options. The SRP would like to commend Dr. Oubre and Dr. Douglas for their detailed presentations, as well the frank, refreshing, and comprehensive engineering presentation. This gave much needed perspective to the food storage issues and reassured the committee about NASA's approach to the problem. In terms of critiques, the SRP remains unconvinced about the rationale for probiotic use other than for specific applications supported by the literature. It is not clear what gap or problem is being addressed by the use of probiotics, and the rationale for their use needs to be clearly rooted in the available literature. The SRP thinks that if low-Earth orbit is associated with immune system impairment, then there may additional risks linked with the use of probiotics. It is not clear to the SRP how NASA will determine if probiotics are having their intended beneficial effect. A similar concern is raised as to what gaps or problems are being addressed by "functional foods". Mixed infections, rather than single species infections, which can augment severity of disease, also represent a significant concern. Overall, the SRP considers this to be a strong program that is well-organized, well-coordinated and generates valuable data.

Nature and the natural environment as health facilitators: the need to reconceptualize the ICF environmental factors.

PubMed

Day, Adam M B; Theurer, Julie A; Dykstra, Allyson D; Doyle, Philip C

2012-01-01

This work examines the environmental factors component of the International Classification of Functioning, Disability, and Health (ICF) relative to current health-facilitating evidence about natural environmental factors. We argue that the environmental factors component warrants reconceptualization in order to offer an extended and more systematic framework for identifying and measuring health-facilitating natural environmental factors. Current evidence highlighting the potential health-facilitating benefits of natural environmental factors is synthesized and considered in the context of the ICF framework and its coding system. In its current form, the ICF's conceptual framework and coding system are inadequate for identifying and measuring natural environmental factors in individuals and groups with and/or without health conditions. The ICF provides an advanced framework for health and disability that reflects contemporary conceptualizations about health. However, given the scope of emerging evidence highlighting positive health and well-being outcomes associated with natural environmental factors, we believe the environmental factors component requires further advancement to reflect this current knowledge. Reconceptualizing the environmental factors component supports a more holistic interpretation of the continuum of environmental factors as both facilitators and barriers. In doing so, it strengthens the ICF's utility in identifying and measuring health-facilitating natural environmental factors.

Advances and Environmental Conditions of Spring Migration Phenology of American White Pelicans

NASA Astrophysics Data System (ADS)

King, D. Tommy; Wang, Guiming; Yang, Zhiqiang; Fischer, Justin W.

2017-01-01

Spring migration phenology of birds has advanced under warming climate. Migration timing of short-distance migrants is believed to be responsive to environmental changes primarily under exogenous control. However, understanding the ecological causes of the advancement in avian spring migration phenology is still a challenge due to the lack of long-term precise location data. We used 11 years of Global Positioning System relocation data to determine four different migration dates of the annual migration cycle of the American white pelican (Pelecanus erythrorhynchos), a short-distance migrant. We also tested the hypothesis that increases in winter temperature and precipitation on the wintering grounds would advance pelican spring migration. Pelican spring departures and arrivals advanced steadily from 2002 to 2011. Spring departure timing exhibited high repeatability at the upper end of migration timing repeatability reported in literature. However, individual spring departure and arrival dates were not related to winter daily temperature, total winter precipitation, and detrended vegetation green-up dates indexed by the normalized difference vegetation index. Despite high repeatability, the observed between-year variation of spring departure dates was still sufficient for the advancement of spring departure timing.

Advances and Environmental Conditions of Spring Migration Phenology of American White Pelicans.

PubMed

King, D Tommy; Wang, Guiming; Yang, Zhiqiang; Fischer, Justin W

2017-01-16

Spring migration phenology of birds has advanced under warming climate. Migration timing of short-distance migrants is believed to be responsive to environmental changes primarily under exogenous control. However, understanding the ecological causes of the advancement in avian spring migration phenology is still a challenge due to the lack of long-term precise location data. We used 11 years of Global Positioning System relocation data to determine four different migration dates of the annual migration cycle of the American white pelican (Pelecanus erythrorhynchos), a short-distance migrant. We also tested the hypothesis that increases in winter temperature and precipitation on the wintering grounds would advance pelican spring migration. Pelican spring departures and arrivals advanced steadily from 2002 to 2011. Spring departure timing exhibited high repeatability at the upper end of migration timing repeatability reported in literature. However, individual spring departure and arrival dates were not related to winter daily temperature, total winter precipitation, and detrended vegetation green-up dates indexed by the normalized difference vegetation index. Despite high repeatability, the observed between-year variation of spring departure dates was still sufficient for the advancement of spring departure timing.

Effects of Benthic Barriers on Macroinvertebrate Communities

DTIC Science & Technology

1993-10-01

Aquatic Plant Control Research Program Effects of Benthic Barriers on Macroinvertebrate Communities by Barry S. Payne, Andrew C. Miller Environmental...Plant Control Technical Report A-93-5Resear h Program Oct ber 1993 Effects of Benthic Barriers on Macroinvertebrate Communities by Barry S. Payne...Effects of benthic barriers on macroinvertebrate communities / by Barry S. Payne, Andrew C. Miller, [and] Thomas Ussery ; prepared for U.S. Army Corps of

Advances in satellite remote sensing of environmental variables for epidemiological applications.

PubMed

Goetz, S J; Prince, S D; Small, J

2000-01-01

Earth-observing satellites have provided an unprecedented view of the land surface but have been exploited relatively little for the measurement of environmental variables of particular relevance to epidemiology. Recent advances in techniques to recover continuous fields of air temperature, humidity, and vapour pressure deficit from remotely sensed observations have significant potential for disease vector monitoring and related epidemiological applications. We report on the development of techniques to map environmental variables with relevance to the prediction of the relative abundance of disease vectors and intermediate hosts. Improvements to current methods of obtaining information on vegetation properties, canopy and surface temperature and soil moisture over large areas are also discussed. Algorithms used to measure these variables incorporate visible, near-infrared and thermal infrared radiation observations derived from time series of satellite-based sensors, focused here primarily but not exclusively on the Advanced Very High Resolution Radiometer (AVHRR) instruments. The variables compare favourably with surface measurements over a broad array of conditions at several study sites, and maps of retrieved variables captured patterns of spatial variability comparable to, and locally more accurate than, spatially interpolated meteorological observations. Application of multi-temporal maps of these variables are discussed in relation to current epidemiological research on the distribution and abundance of some common disease vectors.

Barriers to Advance Care Planning at the End of Life: An Explanatory Systematic Review of Implementation Studies

PubMed Central

Lund, Susi; Richardson, Alison; May, Carl

2015-01-01

Context Advance Care Plans (ACPs) enable patients to discuss and negotiate their preferences for the future including treatment options at the end of life. Their implementation poses significant challenges. Objective To investigate barriers and facilitators to the implementation of ACPs, focusing on their workability and integration in clinical practice. Design An explanatory systematic review of qualitative implementation studies. Data sources Empirical studies that reported interventions designed to support ACP in healthcare. Web of Knowledge, Ovid MEDLINE, CINAHL, PsycINFO, British Nursing Index and PubMed databases were searched. Methods Direct content analysis, using Normalization Process Theory, to identify and characterise relevant components of implementation processes. Results 13 papers identified from 166 abstracts were included in the review. Key factors facilitating implementation were: specially prepared staff utilizing a structured approach to interactions around ACPs. Barriers to implementation were competing demands of other work, the emotional and interactional nature of patient-professional interactions around ACPs, problems in sharing decisions and preferences within and between healthcare organizations. Conclusions This review demonstrates that doing more of the things that facilitate delivery of ACPs will not reduce the effects of those things that undermine them. Structured tools are only likely to be partially effective and the creation of a specialist cadre of ACP facilitators is unlikely to be a sustainable solution. The findings underscore both the challenge and need to find ways to routinely incorporate ACPs in clinical settings where multiple and competing demands impact on practice. Interventions most likely to meet with success are those that make elements of Advance Care Planning workable within complex and time pressured clinical workflows. PMID:25679395

Silicon based substrate with environmental/thermal barrier layer

NASA Technical Reports Server (NTRS)

Eaton, Jr., Harry Edwin (Inventor); Allen, William Patrick (Inventor); Jacobson, Nathan S. (Inventor); Bansal, Narottam P. (Inventor); Opila, Elizabeth J. (Inventor); Smialek, James L. (Inventor); Lee, Kang N. (Inventor); Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Meschter, Peter Joel (Inventor)

2002-01-01

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Silicon based substrate with environmental/ thermal barrier layer

NASA Technical Reports Server (NTRS)

Eaton, Jr., Harry Edwin (Inventor); Allen, William Patrick (Inventor); Jacobson, Nathan S. (Inventor); Bansal, Nanottam P. (Inventor); Opila, Elizabeth J. (Inventor); Smialek, James L. (Inventor); Lee, Kang N. (Inventor); Spitsberg, Irene T. (Inventor); Wang, Hongyu (Inventor); Meschter, Peter Joel (Inventor)

2002-01-01

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.

Barriers to and Facilitators of South Asian Indian-Americans’ Engagement in Advanced Care Planning Behaviors

PubMed Central

Radhakrishnan, Kavita; Saxena, Shubhada; Jillapalli, Regina; Jang, Yuri; Kim, Miyong

2018-01-01

Purpose To identify barriers to and facilitators of older South Asian Indian-Americans’ (SAIAs’) engagement in behaviors associated with advance care planning (ACP). Methods Using a descriptive qualitative design guided by the transcultural nursing assessment model, data were collected in focus groups of community-dwelling older SAIA participants, SAIA family caregivers, and SAIA physicians. A directed approach using predetermined coding categories derived from the Transcultural Nursing Assessment model and aided by NVivo 10 software (Melbourne, Australia) facilitated the qualitative data analysis. Results Eleven focus groups with 36 older SAIAs (61% female, 83% 70+ years old), 10 SAIA family caregivers, and 4 SAIA physicians indicated prior lack of awareness of ACP, good health status, lack of access to linguistically and health literacy–tailored materials, healthcare provider hesitation to initiate discussions on ACP, trust in healthcare providers’ or oldest sons’ decision making, busy family caregiver work routines, and cultural assumptions about filial piety and after-death rituals as major barriers to engaging in ACP. Introducing ACP using personal anecdotes in a neutral, group-based community setting and incentivizing ACP discussions by including long-term care planning were suggested as facilitators to engage in ACP. Clinical Relevance The study’s findings will guide development of culturally sensitive interventions to raise awareness about ACP among SAIAs and encourage SAIA older adults to engage in ACP. PMID:28388828

Barriers to and Facilitators of South Asian Indian-Americans' Engagement in Advanced Care Planning Behaviors.

PubMed

Radhakrishnan, Kavita; Saxena, Shubhada; Jillapalli, Regina; Jang, Yuri; Kim, Miyong

2017-05-01

To identify barriers to and facilitators of older South Asian Indian-Americans' (SAIAs') engagement in behaviors associated with advance care planning (ACP). Using a descriptive qualitative design guided by the transcultural nursing assessment model, data were collected in focus groups of community-dwelling older SAIA participants, SAIA family caregivers, and SAIA physicians. A directed approach using predetermined coding categories derived from the Transcultural Nursing Assessment model and aided by NVivo 10 software (Melbourne, Australia) facilitated the qualitative data analysis. Eleven focus groups with 36 older SAIAs (61% female, 83% 70+ years old), 10 SAIA family caregivers, and 4 SAIA physicians indicated prior lack of awareness of ACP, good health status, lack of access to linguistically and health literacy-tailored materials, healthcare provider hesitation to initiate discussions on ACP, trust in healthcare providers' or oldest sons' decision making, busy family caregiver work routines, and cultural assumptions about filial piety and after-death rituals as major barriers to engaging in ACP. Introducing ACP using personal anecdotes in a neutral, group-based community setting and incentivizing ACP discussions by including long-term care planning were suggested as facilitators to engage in ACP. The study's findings will guide development of culturally sensitive interventions to raise awareness about ACP among SAIAs and encourage SAIA older adults to engage in ACP. © 2017 Sigma Theta Tau International.

Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

NASA Astrophysics Data System (ADS)

Draper, Alison J.

2004-02-01

In an advanced environmental chemistry course, the inclusion of semester-long scientific service projects successfully integrated the research process with course content. Each project involved a unique community-based environmental analysis in which students assessed an aspect of environmental health. The projects were due in small pieces at even intervals, and students worked independently or in pairs. Initially, students wrote a project proposal in which they chose and justified a project. Following a literature review of their topic, they drafted sampling and analysis plans using methods in the literature. Samples were collected and analyzed, and all students assembled scientific posters describing the results of their study. In the last week of the semester, the class traveled to a regional professional meeting to present the posters. In all, students found the experience valuable. They learned to be professional environmental chemists and learned the value of the discipline to community health. Students not only learned about their own project in depth, but they were inspired to learn textbook material, not for an exam, but because it helped them understand their own project. Finally, having a community to answer to at the end of the project motivated students to do careful work.

The rodent research animal holding facility as a barrier to environmental contamination

NASA Technical Reports Server (NTRS)

Savage, P. D., Jr.; Jahns, G. C.; Dalton, B. P.; Hogan, R. P.; Wray, A. E.

1989-01-01

The rodent Research Animal Holding Facility (RAHF), developed by NASA Ames Research Center (ARC) to separately house rodents in a Spacelab, was verified as a barrier to environmental contaminants during a 12-day biocompatibility test. Environmental contaminants considered were solid particulates, microorganisms, ammonia, and typical animal odors. The 12-day test conducted in August 1988 was designed to verify that the rodent RAHF system would adequately support and maintain animal specimens during normal system operations. Additional objectives of this test were to demonstrate that: (1) the system would capture typical particulate debris produced by the animal; (2) microorganisms would be contained; and (3) the passage of animal odors was adequately controlled. In addition, the amount of carbon dioxide exhausted by the RAHF system was to be quantified. Of primary importance during the test was the demonstration that the RAHF would contain particles greater than 150 micrometers. This was verified after analyzing collection plates placed under exhaust air ducts and rodent cages during cage maintenance operations, e.g., waste tray and feeder changeouts. Microbiological testing identified no additional organisms in the test environment that could be traced to the RAHF. Odor containment was demonstrated to be less than barely detectable. Ammonia could not be detected in the exhaust air from the RAHF system. Carbon dioxide levels were verified to be less than 0.35 percent.

The rodent Research Animal Holding Facility as a barrier to environmental contamination

NASA Technical Reports Server (NTRS)

Savage, P. D., Jr.; Jahns, G. C.; Dalton, B. P.; Hogan, R. P.; Wray, A. E.

1989-01-01

The rodent Research Animal Holding Facility (RAHF), developed by NASA Ames Research Center (ARC) to separately house rodents in a Spacelab, was verified as a barrier to environmental contaminants during a 12-day biocompatibility test. Environmental contaminants considered were solid particulates, microorganisms, ammonia, and typical animal odors. The 12-day test conducted in August 1988 was designed to verify that the rodent RAHF system would adequately support and maintain animal specimens during normal system operations. Additional objectives of this test were to demonstrate that: (1) the system would capture typical particulate debris produced by the animal; (2) microorganisms would be contained; and (3) the passage of animal odors was adequately controlled. In addition, the amount of carbon dioxide exhausted by the RAHF system was to be quantified. Of primary importance during the test was the demonstration that the RAHF would contain particles greater than 150 micrometers. This was verified after analyzing collection plates placed under exhaust air ducts and and rodent cages during cage maintenance operations, e.g., waste tray and feeder changeouts. Microbiological testing identified no additional organisms in the test environment that could be traced to the RAHF. Odor containment was demonstrated to be less than barely detectable. Ammonia could not be detected in the exhaust air from the RAHF system. Carbon dioxide levels were verified to be less than 0.35 percent.

Advanced Containment System

DOEpatents

Kostelnik, Kevin M.; Kawamura, Hideki; Richardson, John G.; Noda, Masaru

2005-02-08

An advanced containment system for containing buried waste and associated leachate. The advanced containment system comprises a plurality of casing sections with each casing section interlocked to an adjacent casing section. Each casing section includes a complementary interlocking structure that interlocks with the complementary interlocking structure on an adjacent casing section. A barrier filler substantially fills the casing sections and may substantially fill the spaces of the complementary interlocking structure to form a substantially impermeable barrier. Some of the casing sections may include sensors so that the casing sections and the zone of interest may be remotely monitored after the casing sections are emplaced in the ground.

Advances in quantifying air-sea gas exchange and environmental forcing.

PubMed

Wanninkhof, Rik; Asher, William E; Ho, David T; Sweeney, Colm; McGillis, Wade R

2009-01-01

The past decade has seen a substantial amount of research on air-sea gas exchange and its environmental controls. These studies have significantly advanced the understanding of processes that control gas transfer, led to higher quality field measurements, and improved estimates of the flux of climate-relevant gases between the ocean and atmosphere. This review discusses the fundamental principles of air-sea gas transfer and recent developments in gas transfer theory, parameterizations, and measurement techniques in the context of the exchange of carbon dioxide. However, much of this discussion is applicable to any sparingly soluble, non-reactive gas. We show how the use of global variables of environmental forcing that have recently become available and gas exchange relationships that incorporate the main forcing factors will lead to improved estimates of global and regional air-sea gas fluxes based on better fundamental physical, chemical, and biological foundations.

Barriers to, and Facilitators of Physical Activity in Patients Receiving Chemotherapy for Lung Cancer: An exploratory study.

PubMed

Mas, Sébastien; Quantin, Xavier; Ninot, Grégory

2015-01-01

Physical activity (PA) has a positive effect on the cardiorespiratory fitness, lung cancer symptoms, and quality of life of lung cancer patients. The aim of our study was to identify barriers to, and facilitators of PA in lung cancer patients. We collected data from five patients diagnosed with primary, advanced non-small-cell lung cancer (NSCLC) who were receiving chemotherapy. Choosing a qualitative approach, we conducted an exploratory analysis using the thematic analysis technique to process the data. Seven barriers to, and facilitators of PA were identified and grouped into four categories. We found that psychological and social factors affect patients' willingness and ability to engage in PA, while physiological and environmental factors have an impact on the duration, intensity, and regularity of their PA. Our study highlighted some of the effects that the barriers to PA have on the practice of it in our patient group. Our findings may be used by professionals to design adapted PA programs.

Improving Voluntary Environmental Management Programs: Facilitating Learning and Adaptation

NASA Astrophysics Data System (ADS)

Genskow, Kenneth D.; Wood, Danielle M.

2011-05-01

Environmental planners and managers face unique challenges understanding and documenting the effectiveness of programs that rely on voluntary actions by private landowners. Programs, such as those aimed at reducing nonpoint source pollution or improving habitat, intend to reach those goals by persuading landowners to adopt behaviors and management practices consistent with environmental restoration and protection. Our purpose with this paper is to identify barriers for improving voluntary environmental management programs and ways to overcome them. We first draw upon insights regarding data, learning, and adaptation from the adaptive management and performance management literatures, describing three key issues: overcoming information constraints, structural limitations, and organizational culture. Although these lessons are applicable to a variety of voluntary environmental management programs, we then present the issues in the context of on-going research for nonpoint source water quality pollution. We end the discussion by highlighting important elements for advancing voluntary program efforts.

Women as radiologists: are there barriers to entry and advancement?

PubMed

Baker, Stephen R; Barry, Maureen; Chaudhry, Hamaira; Hubbi, Basil

2006-02-01

proportion to the overall number of women in the organization. However, women continue to be underrepresented in radiology chair positions. Explanations must be sought for the relative unattractiveness of radiology to prospective women residents and barriers to the advancement of women in academic radiology.

Environmental performance evaluation of an advanced-design solid-state television camera

NASA Technical Reports Server (NTRS)

1979-01-01

The development of an advanced-design black-and-white solid-state television camera which can survive exposure to space environmental conditions was undertaken. A 380 x 488 element buried-channel CCD is utilized as the image sensor to ensure compatibility with 525-line transmission and display equipment. Specific camera design approaches selected for study and analysis included: (1) component and circuit sensitivity to temperature; (2) circuit board thermal and mechanical design; and (3) CCD temperature control. Preferred approaches were determined and integrated into the final design for two deliverable solid-state TV cameras. One of these cameras was subjected to environmental tests to determine stress limits for exposure to vibration, shock, acceleration, and temperature-vacuum conditions. These tests indicate performance at the design goal limits can be achieved for most of the specified conditions.

Barriers to Leisure-Time Physical Activities in Individuals with Spinal Cord Injury.

PubMed

Hwang, Eric J; Groves, Mary D; Sanchez, Jacqueline N; Hudson, Cassandra E; Jao, Rachel G; Kroll, Meghan E

2016-07-01

This study investigated the personal, environmental, and activity barriers to leisure-time physical activities (LTPAs) among individuals with spinal cord injury (SCI). A survey instrument was administered to 85 participants with SCI. Personal barriers to LTPAs included issues involving motivation, pain, scheduling, and financial resources. Environmental barriers marked the issues regarding availability and accessibility to specialized programs, activities, and professional services. Activity barriers included limitations in equipment, training, and personal skills required by the selected activities. Significant negative correlations were found between these barriers and the levels of physical activity and satisfaction with physical activity. While working with clients with SCI, occupational therapists should identify those LTPA barriers and possible solutions in order to establish individualized action plans for enhancing participation in LTPAs.

Degradation Of Environmental Barrier Coatings (EBC) Due To Chemical and Thermal Expansion Incompatibility

NASA Technical Reports Server (NTRS)

Lee, Kang N.; King, Deboran (Technical Monitor)

2001-01-01

Current environmental barrier coatings (EBCs) consist of multiple layers, with each layer having unique properties to meet the various requirements for successful EBCs. As a result, chemical and thermal expansion compatibility between layers becomes an important issue to maintaining durability. Key constituents in current EBCs are mullite (3Al2O3-2SiO2), BSAS (BaO(1-x)-SrO(x)-Al2O3-2SiO2), and YSZ (ZrO2-8 wt.% Y2O3). The mullite-BSAS combination appears benign although significant diffusion occurs. Mullite-YSZ and BSAS-YSZ combinations do not react up to 1500 C. Thermally grown SiO2- BSAS and mullite-BSAS-YSZ combinations are most detrimental, forming low melting glasses. Thermal expansion mismatch between YSZ and mullite or BSAS causes severe cracking and delamination.

Advances in the Dynallax solid-state dynamic parallax barrier autostereoscopic visualization display system.

PubMed

Peterka, Tom; Kooima, Robert L; Sandin, Daniel J; Johnson, Andrew; Leigh, Jason; DeFanti, Thomas A

2008-01-01

A solid-state dynamic parallax barrier autostereoscopic display mitigates some of the restrictions present in static barrier systems, such as fixed view-distance range, slow response to head movements, and fixed stereo operating mode. By dynamically varying barrier parameters in real time, viewers may move closer to the display and move faster laterally than with a static barrier system, and the display can switch between 3D and 2D modes by disabling the barrier on a per-pixel basis. Moreover, Dynallax can output four independent eye channels when two viewers are present, and both head-tracked viewers receive an independent pair of left-eye and right-eye perspective views based on their position in 3D space. The display device is constructed by using a dual-stacked LCD monitor where a dynamic barrier is rendered on the front display and a modulated virtual environment composed of two or four channels is rendered on the rear display. Dynallax was recently demonstrated in a small-scale head-tracked prototype system. This paper summarizes the concepts presented earlier, extends the discussion of various topics, and presents recent improvements to the system.

Advanced reactors and associated fuel cycle facilities: safety and environmental impacts.

PubMed

Hill, R N; Nutt, W M; Laidler, J J

2011-01-01

The safety and environmental impacts of new technology and fuel cycle approaches being considered in current U.S. nuclear research programs are contrasted to conventional technology options in this paper. Two advanced reactor technologies, the sodium-cooled fast reactor (SFR) and the very high temperature gas-cooled reactor (VHTR), are being developed. In general, the new reactor technologies exploit inherent features for enhanced safety performance. A key distinction of advanced fuel cycles is spent fuel recycle facilities and new waste forms. In this paper, the performance of existing fuel cycle facilities and applicable regulatory limits are reviewed. Technology options to improve recycle efficiency, restrict emissions, and/or improve safety are identified. For a closed fuel cycle, potential benefits in waste management are significant, and key waste form technology alternatives are described. Copyright © 2010 Health Physics Society

Overview of thermal barrier coatings in diesel engines

NASA Technical Reports Server (NTRS)

Yonushonis, T. M.

1995-01-01

An understanding of delamination mechanisms in thermal barrier coatings has been developed for diesel applications through nondestructive evaluation, structural analysis modeling and engine evaluation of various thermal barrier coatings. This knowledge has resulted in improved thermal barrier coatings which survive abusive cyclic fatigue tests in high output diesel engines. Significant efforts are still required to improve the plasma spray processing capability and the economics for complex geometry diesel engine components. Data obtained from advanced diesel engines on the effect of thermal barrier coatings on engine fuel economy and emission has not been encouraging. Although the underlying metal component temperatures have been reduced through the use of thermal barrier coating, engine efficiency and emission trends have not been promising.

Advances in analytical technologies for environmental protection and public safety.

PubMed

Sadik, O A; Wanekaya, A K; Andreescu, S

2004-06-01

Due to the increased threats of chemical and biological agents of injury by terrorist organizations, a significant effort is underway to develop tools that can be used to detect and effectively combat chemical and biochemical toxins. In addition to the right mix of policies and training of medical personnel on how to recognize symptoms of biochemical warfare agents, the major success in combating terrorism still lies in the prevention, early detection and the efficient and timely response using reliable analytical technologies and powerful therapies for minimizing the effects in the event of an attack. The public and regulatory agencies expect reliable methodologies and devices for public security. Today's systems are too bulky or slow to meet the "detect-to-warn" needs for first responders such as soldiers and medical personnel. This paper presents the challenges in monitoring technologies for warfare agents and other toxins. It provides an overview of how advances in environmental analytical methodologies could be adapted to design reliable sensors for public safety and environmental surveillance. The paths to designing sensors that meet the needs of today's measurement challenges are analyzed using examples of novel sensors, autonomous cell-based toxicity monitoring, 'Lab-on-a-Chip' devices and conventional environmental analytical techniques. Finally, in order to ensure that the public and legal authorities are provided with quality data to make informed decisions, guidelines are provided for assessing data quality and quality assurance using the United States Environmental Protection Agency (US-EPA) methodologies.

Phase transformations and residual stresses in environmental barrier coatings

NASA Astrophysics Data System (ADS)

Harder, Bryan J.

Silicon-based ceramics (SiC, Si3N4) are promising materials for high-temperature structural applications in turbine engines. However, the silica layer that forms on these materials is susceptible to attack from water vapor present in combustion environments. To protect against this degradation, environmental barrier coatings (EBCs) were developed to protect the underlying substrate. In the case of silicon carbide (SiC), multilayer coating systems consist of a Ba1-xSrxAl2Si 2O8 (BSAS) topcoat, a mullite or mullite + SrAl2Si 2O8 (SAS) interlayer, and a silicon bond coat. In this work, biaxial strains were measured on as-sprayed and heat-treated samples to analyze the stress and phase evolution in the coating system as a function of depth and temperature. Models were used to compare the results with an ideal coating system. In the assprayed state, tensile stresses as high as 175 MPa were measured, and cracking was observed. After thermally cycling the samples, stresses were significantly reduced and cracks in the topcoat had closed. The addition of SAS to the interlayer increased the compressive stress in the BSAS topcoat in thermally-cycled samples, which was desirable for EBC applications. The BSAS topcoat transformed from the as-deposited hexacelsian state to the stable celsian above 1200°C. This phase transformation is accompanied by a CTE reduction. The kinetics of the hexacelsian-to-celsian transformation were quantified for freestanding plasma-sprayed BSAS. Activation energies for bulk bars and crushed powder were determined to be ˜340 kJ/mol and ˜500 kJ/mol, respectively. X-ray diffraction and electron backscatter diffraction were used to establish how microstructural constraints reduce the transformation energy. Barrier coating lifetime and stability are also influenced by exposure to reactive, low-melting point calcium-magnesium-aluminosilicate (CMAS) deposits formed from dust and sand. Multilayer doped aluminosilicate coatings and bulk BSAS material were

Advancing an Information Model for Environmental Observations

NASA Astrophysics Data System (ADS)

Horsburgh, J. S.; Aufdenkampe, A. K.; Hooper, R. P.; Lehnert, K. A.; Schreuders, K.; Tarboton, D. G.; Valentine, D. W.; Zaslavsky, I.

2011-12-01

have been modified to support data management for the Critical Zone Observatories (CZOs). This paper will present limitations of the existing information model used by the CUAHSI HIS that have been uncovered through its deployment and use, as well as new advances to the information model, including: better representation of both in situ observations from field sensors and observations derived from environmental samples, extensibility in attributes used to describe observations, and observation provenance. These advances have been developed by the HIS team and the broader scientific community and will enable the information model to accommodate and better describe wider classes of environmental observations and to better meet the needs of the hydrologic science and CZO communities.

Performance Evaluation and Modeling of Erosion Resistant Turbine Engine Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

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

2008-01-01

The erosion resistant turbine thermal barrier coating system is critical to the rotorcraft engine performance and durability. The objective of this work was to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and thermal gradient environments, thus validating a new thermal barrier coating turbine blade technology for future rotorcraft applications. A high velocity burner rig based erosion test approach was established and a new series of rare earth oxide- and TiO2/Ta2O5- alloyed, ZrO2-based low conductivity thermal barrier coatings were designed and processed. The low conductivity thermal barrier coating systems demonstrated significant improvements in the erosion resistance. A comprehensive model based on accumulated strain damage low cycle fatigue is formulated for blade erosion life prediction. The work is currently aiming at the simulated engine erosion testing of advanced thermal barrier coated turbine blades to establish and validate the coating life prediction models.

Gamification - Environmental and Sustainable Development Organizations Could Do More

NASA Astrophysics Data System (ADS)

Ziegler, C. R.; Miller, C. A.; Kilaru, V.; French, R. A.; Costanza, R.; Brookes, A.

2013-12-01

The use of digital games to foster sustainable development and environmental goals has grown over the last 10 years. Innovative thinking and the origins of 'serious games,' 'games for change' and 'gamification' are partly rooted in movies and science fiction. Existing games illustrate a spectrum of approaches: for example, World Food Programme's FoodForce and University of Washington's Foldit. Environmental organizations globally (e.g. US EPA) have dabbled with game development and gamification, but have only touched the tip of the iceberg, particularly when compared to the success of the commercial gaming industry. We explore: 1) the intersection of environmental organization mission statements in the context of gamification efforts , 2) some examples of existing games, from simple to complex, 3) business model approaches (e.g. game development partnerships with academia, private industry, NGOs, etc.), 4) barriers, and 5) benefits of a more concerted and technologically-advanced approach to gamification for environmental organizations.

Latitudinal environmental niches and riverine barriers shaped the phylogeography of the Central Chilean endemic Dioscorea humilis (Dioscoreaceae).

PubMed

Viruel, Juan; Catalán, Pilar; Segarra-Moragues, José Gabriel

2014-01-01

The effects of Pleistocene glaciations and geographical barriers on the phylogeographic patterns of lowland plant species in Mediterranean-climate areas of Central Chile are poorly understood. We used Dioscorea humilis (Dioscoreaceae), a dioecious geophyte extending 530 km from the Valparaíso to the Bío-Bío Regions, as a case study to disentangle the spatio-temporal evolution of populations in conjunction with latitudinal environmental changes since the Last Inter-Glacial (LIG) to the present. We used nuclear microsatellite loci, chloroplast (cpDNA) sequences and environmental niche modelling (ENM) to construct current and past scenarios from bioclimatic and geographical variables and to infer the evolutionary history of the taxa. We found strong genetic differentiation at nuclear microsatellite loci between the two subspecies of D. humilis, probably predating the LIG. Bayesian analyses of population structure revealed strong genetic differentiation of the widespread D. humilis subsp. humilis into northern and southern population groups, separated by the Maipo river. ENM revealed that the ecological niche differentiation of both groups have been maintained up to present times although their respective geographical distributions apparently fluctuated in concert with the climatic oscillations of the Last Glacial Maximum (LGM) and the Holocene. Genetic data revealed signatures of eastern and western postglacial expansion of the northern populations from the central Chilean depression, whereas the southern ones experienced a rapid southward expansion after the LGM. This study describes the complex evolutionary histories of lowland Mediterranean Chilean plants mediated by the summed effects of spatial isolation caused by riverine geographical barriers and the climatic changes of the Quaternary.

Latitudinal Environmental Niches and Riverine Barriers Shaped the Phylogeography of the Central Chilean Endemic Dioscorea humilis (Dioscoreaceae)

PubMed Central

Viruel, Juan; Catalán, Pilar; Segarra-Moragues, José Gabriel

2014-01-01

The effects of Pleistocene glaciations and geographical barriers on the phylogeographic patterns of lowland plant species in Mediterranean-climate areas of Central Chile are poorly understood. We used Dioscorea humilis (Dioscoreaceae), a dioecious geophyte extending 530 km from the Valparaíso to the Bío-Bío Regions, as a case study to disentangle the spatio-temporal evolution of populations in conjunction with latitudinal environmental changes since the Last Inter-Glacial (LIG) to the present. We used nuclear microsatellite loci, chloroplast (cpDNA) sequences and environmental niche modelling (ENM) to construct current and past scenarios from bioclimatic and geographical variables and to infer the evolutionary history of the taxa. We found strong genetic differentiation at nuclear microsatellite loci between the two subspecies of D. humilis, probably predating the LIG. Bayesian analyses of population structure revealed strong genetic differentiation of the widespread D. humilis subsp. humilis into northern and southern population groups, separated by the Maipo river. ENM revealed that the ecological niche differentiation of both groups have been maintained up to present times although their respective geographical distributions apparently fluctuated in concert with the climatic oscillations of the Last Glacial Maximum (LGM) and the Holocene. Genetic data revealed signatures of eastern and western postglacial expansion of the northern populations from the central Chilean depression, whereas the southern ones experienced a rapid southward expansion after the LGM. This study describes the complex evolutionary histories of lowland Mediterranean Chilean plants mediated by the summed effects of spatial isolation caused by riverine geographical barriers and the climatic changes of the Quaternary. PMID:25295517

Recent advances and opportunities in research on lupus: environmental influences and mechanisms of disease.

PubMed

Cooper, Glinda S; Gilbert, Kathleen M; Greidinger, Eric L; James, Judith A; Pfau, Jean C; Reinlib, Leslie; Richardson, Bruce C; Rose, Noel R

2008-06-01

In this review we summarize research on mechanisms through which environmental agents may affect the pathogenesis of lupus, discuss three exposures that have been the focus of research in this area, and propose recommendations for new research initiatives. We examined studies pertaining to key mechanistic events and specific exposures. Apoptosis leading to increased production or decreased clearance of immunogenic intracellular self-antigens and defective apoptosis of autoreactive immune cells both have been implicated in the loss of self-tolerance. The adjuvant or bystander effect is also needed to produce a sustained autoimmune response. Activation of toll-like receptors is one mechanism through which these effects may occur. Abnormal DNA methylation may also contribute to the pathogenesis of lupus. Each of the specific exposures we examined--Epstein-Barr virus, silica, and trichloroethylene--has been shown, in humans or in mice, to act upon one or more of these pathogenic steps. Specific recommendations for the continued advancement of our understanding of environmental influences on lupus and other autoimmune diseases include the development and use of mouse models with varying degrees of penetrance and manifestations of disease, identification of molecular or physiologic targets of specific exposures, development and use of improved exposure assessment methodologies, and multisite collaborations designed to examine understudied environmental exposures in humans. The advances made in the past decade concerning our understanding of mechanisms involved in the development of lupus and the influence of environmental agents on this process provide a strong foundation for further developments in this field.

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

NASA Technical Reports Server (NTRS)

Zhu, Dongming

2018-01-01

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

The environmental control and life support system advanced automation project. Phase 1: Application evaluation

NASA Technical Reports Server (NTRS)

Dewberry, Brandon S.

1990-01-01

The Environmental Control and Life Support System (ECLSS) is a Freedom Station distributed system with inherent applicability to advanced automation primarily due to the comparatively large reaction times of its subsystem processes. This allows longer contemplation times in which to form a more intelligent control strategy and to detect or prevent faults. The objective of the ECLSS Advanced Automation Project is to reduce the flight and ground manpower needed to support the initial and evolutionary ECLS system. The approach is to search out and make apparent those processes in the baseline system which are in need of more automatic control and fault detection strategies, to influence the ECLSS design by suggesting software hooks and hardware scars which will allow easy adaptation to advanced algorithms, and to develop complex software prototypes which fit into the ECLSS software architecture and will be shown in an ECLSS hardware testbed to increase the autonomy of the system. Covered here are the preliminary investigation and evaluation process, aimed at searching the ECLSS for candidate functions for automation and providing a software hooks and hardware scars analysis. This analysis shows changes needed in the baselined system for easy accommodation of knowledge-based or other complex implementations which, when integrated in flight or ground sustaining engineering architectures, will produce a more autonomous and fault tolerant Environmental Control and Life Support System.

Environmental barriers and enablers to physical activity participation among rural adults: a qualitative study.

PubMed

Cleland, Verity; Hughes, Clarissa; Thornton, Lukar; Squibb, Kathryn; Venn, Alison; Ball, Kylie

2015-08-01

Social-ecological models of health behaviour acknowledge environmental influences, but research examining how the environment shapes physical activity in rural settings is limited. This study aimed to explore the environmental factors that act as barriers or facilitators to physical activity participation among rural adults. Forty-nine adults from three regions of rural Tasmania, Australia, participated in semi-structured interviews that explored features of the environment that supported or hindered physical activity. Interviews were digitally recorded, transcribed verbatim and analysed thematically. Four key themes emerged: functionality, diversity, spaces and places for all and realistic expectations. 'Functionality' included connectivity with other destinations, distance, safety, continuity, supporting infrastructure and surfacing. While there was limited 'diversity' of structured activities and recreational facilities, the importance of easy and convenient access to a natural environment that accommodated physical activity was highlighted. 'Spaces and places for all' highlighted the importance of shared-use areas, particularly those that were family- and dog-friendly. Despite desires for more physical activity opportunities, many participants had 'realistic expectations' of what was feasible in rural settings. Functionality, diversity, spaces and places for all and realistic expectations were identified as considerations important for physical activity among rural adults. Further research using quantitative approaches in larger samples is needed to confirm these findings. SO WHAT? Urban-centric views of environmental influences on physical activity are unlikely to be entirely appropriate for rural areas. Evidence-based recommendations are provided for creating new or modifying existing infrastructure to support active living in rural settings.

Recent Advance in Liquid Chromatography/Mass Spectrometry Techniques for Environmental Analysis in Japan

PubMed Central

Suzuki, Shigeru

2014-01-01

The techniques and measurement methods developed in the Environmental Survey and Monitoring of Chemicals by Japan’s Ministry of the Environment, as well as a large amount of knowledge archived in the survey, have led to the advancement of environmental analysis. Recently, technologies such as non-target liquid chromatography/high resolution mass spectrometry and liquid chromatography with micro bore column have further developed the field. Here, the general strategy of a method developed for the liquid chromatography/mass spectrometry (LC/MS) analysis of environmental chemicals with a brief description is presented. Also, a non-target analysis for the identification of environmental pollutants using a provisional fragment database and “MsMsFilter,” an elemental composition elucidation tool, is presented. This analytical method is shown to be highly effective in the identification of a model chemical, the pesticide Bendiocarb. Our improved micro-liquid chromatography injection system showed substantially enhanced sensitivity to perfluoroalkyl substances, with peak areas 32–71 times larger than those observed in conventional LC/MS. PMID:26819891

Formulation of advanced consumables management models: Executive summary. [modeling spacecraft environmental control, life support, and electric power supply systems

NASA Technical Reports Server (NTRS)

Daly, J. K.; Torian, J. G.

1979-01-01

An overview of studies conducted to establish the requirements for advanced subsystem analytical tools is presented. Modifications are defined for updating current computer programs used to analyze environmental control, life support, and electric power supply systems so that consumables for future advanced spacecraft may be managed.

Overview of Advanced Space Propulsion Activities in the Space Environmental Effects Team at MSFC

NASA Technical Reports Server (NTRS)

Edwards, David; Carruth, Ralph; Vaughn, Jason; Schneider, Todd; Kamenetzky, Rachel; Gray, Perry

2000-01-01

Exploration of our solar system, and beyond, requires spacecraft velocities beyond our current technological level. Technologies addressing this limitation are numerous. The Space Environmental Effects (SEE) Team at the Marshall Space Flight Center (MSFC) is focused on three discipline areas of advanced propulsion; Tethers, Beamed Energy, and Plasma. This presentation will give an overview of advanced propulsion related activities in the Space Environmental Effects Team at MSFC. Advancements in the application of tethers for spacecraft propulsion were made while developing the Propulsive Small Expendable Deployer System (ProSEDS). New tether materials were developed to meet the specifications of the ProSEDS mission and new techniques had to be developed to test and characterize these tethers. Plasma contactors were developed, tested and modified to meet new requirements. Follow-on activities in tether propulsion include the Air-SEDS activity. Beamed energy activities initiated with an experimental investigation to quantify the momentum transfer subsequent to high power, 5J, ablative laser interaction with materials. The next step with this experimental investigation is to quantify non-ablative photon momentum transfer. This step was started last year and will be used to characterize the efficiency of solar sail materials before and after exposure to Space Environmental Effects (SEE). Our focus with plasma, for propulsion, concentrates on optimizing energy deposition into a magnetically confined plasma and integration of measurement techniques for determining plasma parameters. Plasma confinement is accomplished with the Marshall Magnetic Mirror (M3) device. Initial energy coupling experiments will consist of injecting a 50 amp electron beam into a target plasma. Measurements of plasma temperature and density will be used to determine the effect of changes in magnetic field structure, beam current, and gas species. Experimental observations will be compared to

Failure Mechanisms and Life Prediction of Thermal and Environmental Barrier Coatings under Thermal Gradients

NASA Technical Reports Server (NTRS)

Zju, Dongming; Ghosn, Louis J.; Miller, Robert A.

2008-01-01

Ceramic thermal and environmental barrier coatings (TEBCs) will play an increasingly important role in gas turbine engines because of their ability to further raise engine temperatures. However, the issue of coating durability is of major concern under high-heat-flux conditions. In particular, the accelerated coating delamination crack growth under the engine high heat-flux conditions is not well understood. In this paper, a laser heat flux technique is used to investigate the coating delamination crack propagation under realistic temperature-stress gradients and thermal cyclic conditions. The coating delamination mechanisms are investigated under various thermal loading conditions, and are correlated with coating dynamic fatigue, sintering and interfacial adhesion test results. A coating life prediction framework may be realized by examining the crack initiation and propagation driving forces for coating failure under high-heat-flux test conditions.

High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

NASA Technical Reports Server (NTRS)

Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

2014-01-01

Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

Residual stresses and phase transformations in Ytterbium silicate environmental barrier coatings

NASA Astrophysics Data System (ADS)

Stolzenburg, Fabian

Due to their high melting temperature, low density, and good thermomechanical stability, silicon-based ceramics (SiC, Si3N4) are some of the most promising materials systems for high temperature structural applications in gas turbine engines. However, their silica surface layer reacts with water vapor contained in combustion environments. The resulting hydroxide layer volatilizes, leading to component recession. Environmental barrier coatings (EBCs) have been developed to shield the substrate from degradation. Next generation coatings for silicon-based ceramics based on ytterbium silicates have shown a promising combination of very low and good thermomechanical properties. The focus of this thesis is threefold: In the first part, phase transformations in plasma sprayed ytterbium silicates were investigated. Plasma sprayed materials are known to contain large amounts of amorphous material. Phase changes during the conversion from amorphous to crystalline materials were investigated as they have been known to lead to failure in many coatings. The second part of this work focused on measuring residual stresses in multilayer EBCs using synchrotron X-ray diffraction (XRD). Strains were resolved spatially, with probe sizes as small as 20 um. Stresses were calculated using mechanical properties of ytterbium silicates, determined with in-situ loading and heating experiments. In-situ and ex-situ heating experiments allowed for the study of changes in stress states that occur in these EBC materials during heating and cooling cycles. Lastly, the interaction of ytterbium silicates with low-melting environmental calcium-magnesium-aluminosilicate (CMAS) glasses was studied. Synchrotron XRD was used to study the influence of CMAS on the stress state in the coating, X-ray computed tomography was used to provide 3D images of coatings, and EDS and TEM analysis were used to study the interactions at the CMAS/ytterbium silicate interface in detail.

Advances in Meningeal Immunity.

PubMed

Rua, Rejane; McGavern, Dorian B

2018-06-01

The central nervous system (CNS) is an immunologically specialized tissue protected by a blood-brain barrier. The CNS parenchyma is enveloped by a series of overlapping membranes that are collectively referred to as the meninges. The meninges provide an additional CNS barrier, harbor a diverse array of resident immune cells, and serve as a crucial interface with the periphery. Recent studies have significantly advanced our understanding of meningeal immunity, demonstrating how a complex immune landscape influences CNS functions under steady-state and inflammatory conditions. The location and activation state of meningeal immune cells can profoundly influence CNS homeostasis and contribute to neurological disorders, but these cells are also well equipped to protect the CNS from pathogens. In this review, we discuss advances in our understanding of the meningeal immune repertoire and provide insights into how this CNS barrier operates immunologically under conditions ranging from neurocognition to inflammatory diseases. Published by Elsevier Ltd.

Methods for quantification of soil-transmitted helminths in environmental media: current techniques and recent advances

PubMed Central

Collender, Philip A.; Kirby, Amy E.; Addiss, David G.; Freeman, Matthew C.; Remais, Justin V.

2015-01-01

Limiting the environmental transmission of soil-transmitted helminths (STH), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost effective methods to detect and quantify STH in the environment. We review the state of the art of STH quantification in soil, biosolids, water, produce, and vegetation with respect to four major methodological issues: environmental sampling; recovery of STH from environmental matrices; quantification of recovered STH; and viability assessment of STH ova. We conclude that methods for sampling and recovering STH require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. PMID:26440788

Modeling Catastrophic Barrier Island Dynamics

NASA Astrophysics Data System (ADS)

Whitley, J. W.; McNamara, D.

2012-12-01

Barrier islands, thin strips of sand lying parallel to the mainland coastline, along the U.S. Atlantic and Gulf Coasts appear to have maintained their form for thousands of years in the face of rising sea level. The mechanisms that allow barrier islands to remain robust are transport of sediment from the ocean side of barriers to the top and backside during storms, termed island overwash, and the growth and alongshore propagation of tidal deltas near barrier island inlets. Dynamically these processes provide the necessary feedbacks to maintain a barrier island in an attractor that withstands rising sea level within a phase space of barrier island geometrical characteristics. Current barrier island configurations along the Atlantic and Gulf coasts exist among a wide range of storm climate and underlying geologic conditions and therefore the environment that forces overwash and tidal delta dynamics varies considerably. It has been suggested that barrier islands in certain locations such as those between Avon and Buxton (losing 76% of island width since 1852) and Chandeleur islands (losing 85% of its surface area since 2005) along the Atlantic and Gulf coasts, respectively, may be subject to a catastrophic shift in barrier island attractor states - more numerous inlets cutting barriers in some locations and the complete disappearance of barrier islands in other locations. In contrast to common models for barrier islands that neglect storm dynamics and often only consider cross-shore response, we use an alongshore extended model for barrier island dynamics including beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms to explore the response of barrier islands to a wide range of environmental forcing. Results will be presented that show how barrier island attractor states are altered with variations in the rate of sea level rise, storminess, and underlying geology. We will

Quantifying the lag time to detect barriers in landscape genetics

Treesearch

E. L. Landguth; S. A Cushman; M. K. Schwartz; K. S. McKelvey; M. Murphy; G. Luikart

2010-01-01

Understanding how spatial genetic patterns respond to landscape change is crucial for advancing the emerging field of landscape genetics. We quantified the number of generations for new landscape barrier signatures to become detectable and for old signatures to disappear after barrier removal. We used spatially explicit, individualbased simulations to examine the...

Life cycle environmental impacts of advanced wastewater treatment techniques for removal of pharmaceuticals and personal care products (PPCPs).

PubMed

Zepon Tarpani, Raphael Ricardo; Azapagic, Adisa

2018-06-01

Pharmaceutical and personal care products (PPCPs) are of increasing interest because of their ecotoxicological properties and environmental impacts. Wastewater treatment plants (WWTPs) are the main pathway for their release into freshwaters due to the inefficiency of conventional WWTPs in removing many of these contaminants from effluents. Therefore, different advanced effluent treatment techniques have been proposed for their treatment. However, it is not known at present how effective these treatment methods are and whether on a life cycle basis they cause other environmental impacts which may outweigh the benefits of the treatment. In an effort to provide an insight into this question, this paper considers life cycle environmental impacts of the following advanced treatment techniques aimed at reducing freshwater ecotoxicity potential of PPCPs: granular activated carbon (GAC), nanofiltration (NF), solar photo-Fenton (SPF) and ozonation. The results suggest that on average NF has the lowest impacts for 13 out of 18 categories considered. GAC is the best alternative for five impacts, including metals and water depletion, but it has the highest marine eutrophication. SPF and ozonation are the least sustainable for eight impacts, including ecotoxicity and climate change. GAC and NF are also more efficient in treating heavy metals while avoiding generation of harmful by-products during the treatment, thus being more suitable for potable reuse of wastewater. However, releasing the effluent without advanced treatment to agricultural land achieves a much higher reduction of freshwater ecotoxicity than treating it by any of the advanced treatments and releasing to the environment. Therefore, the use of advanced effluent treatment for agricultural purposes is not recommended. Copyright © 2018 Elsevier Ltd. All rights reserved.

The advances of Chinese non-ferrous metal mineral industry and its environmental management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao Zewei; Gao Lin; Zhou Xiaoyuan

1998-12-31

With the steady growth of Chinese economy, the nonferrous metal industry of China was also developed quickly. The gross output of ten main nonferrous metals 4.25 million tons in 1995 so that China ranks the fourth in the world. However, a series of environmental problems also occurred, which relate to characteristics of mineral resources, techniques for mining, dressing, smelting and processing, equipment and their management level. The major pollutants include sulphur dioxide, industrial powder-dust and smoke-dust, water containing heavy metal ions as well as solid wastes. Air, water body, soil, vegetation and people`s health were polluted and damaged to differentmore » extent due to the above pollutants. For the purpose of environmental management and pollution control, some measures must be taken: (1) to strengthen environmental planning, accelerate and perfect environmental laws and related regulations as well as spread the consciousness of environmental protection energetically; (2) to extend cleaner production and adopt advanced technologies so as to reduce environmental pollution; (3) to turn the concept of the end-of-pipe management to the whole-process control; (4) to recovery or reuse the wastes fully. In addition, general situation and policies on reclamation of mining land as well as theory, methods and techniques of restoration of waste land were also stated in the paper.« less

Engaging academia to advance the science and practice of environmental public health tracking.

PubMed

Strosnider, Heather; Zhou, Ying; Balluz, Lina; Qualters, Judith

2014-10-01

Public health agencies at the federal, state, and local level are responsible for implementing actions and policies that address health problems related to environmental hazards. These actions and policies can be informed by integrating or linking data on health, exposure, hazards, and population. The mission of the Centers for Disease Control and Prevention׳s National Environmental Public Health Tracking Program (Tracking Program) is to provide information from a nationwide network of integrated health, environmental hazard, and exposure data that drives actions to improve the health of communities. The Tracking Program and federal, state, and local partners collect, integrate, analyze, and disseminate data and information to inform environmental public health actions. However, many challenges exist regarding the availability and quality of data, the application of appropriate methods and tools to link data, and the state of the science needed to link and analyze health and environmental data. The Tracking Program has collaborated with academia to address key challenges in these areas. The collaboration has improved our understanding of the uses and limitations of available data and methods, expanded the use of existing data and methods, and increased our knowledge about the connections between health and environment. Valuable working relationships have been forged in this process, and together we have identified opportunities and improvements for future collaborations to further advance the science and practice of environmental public health tracking. Published by Elsevier Inc.

Advanced situation awareness with localised environmental community observatories in the Future Internet

NASA Astrophysics Data System (ADS)

Sabeur, Z. A.; Denis, H.; Nativi, S.

2012-04-01

The phenomenal advances in information and communication technologies over the last decade have led to offering unprecedented connectivity with real potentials for "Smart living" between large segments of human populations around the world. In particular, Voluntary Groups(VGs) and individuals with interest in monitoring the state of their local environment can be connected through the internet and collaboratively generate important localised environmental observations. These could be considered as the Community Observatories(CO) of the Future Internet(FI). However, a set of FI enablers are needed to be deployed for these communities to become effective COs in the Future Internet. For example, these communities will require access to services for the intelligent processing of heterogeneous data and capture of advancend situation awarness about the environment. This important enablement will really unlock the communities true potential for participating in localised monitoring of the environment in addition to their contribution in the creation of business entreprise. Among the eight Usage Areas(UA) projects of the FP7 FI-PPP programme, the ENVIROFI Integrated Project focuses on the specifications of the Future Internet enablers of the Environment UA. The specifications are developed under multiple environmental domains in context of users needs for the development of mash-up applications in the Future Internet. It will enable users access to real-time, on-demand fused information with advanced situation awareness about the environment at localised scales. The mash-up applications shall get access to rich spatio-temporal information from structured fusion services which aggregate COs information with existing environmental monitoring stations data, established by research organisations and private entreprise. These applications are being developed in ENVIROFI for the atmospheric, marine and biodiversity domains, together with a potential to be extended to other

Symbolic Beliefs as Barriers to Responsible Environmental Behavior.

ERIC Educational Resources Information Center

Jurin, Richard R.; Fortner, Rosane W.

2002-01-01

Presents an exploratory study that investigates how environmental beliefs relate to self-reported environmental behaviors. Includes a student sample (N=110) which was administered a 208-item instrument. Reports that based on survey results, most of the sample perceived themselves as environmentally aware and differed only in strength of attitudes.…

Confronting barriers and recognizing opportunities: Developing effective community-based environmental monitoring programs to meet the needs of Aboriginal communities

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKay, Ariana J., E-mail: ariana.mckay@outlook.com; Johnson, Chris J., E-mail: chris.johnson@unbc.ca

Aboriginal communities can be negatively affected by resource development, but often they do not have a full opportunity to participate in project review and the resulting monitoring and mitigation activities. Cumulative impacts of resource development are also typically neglected in monitoring protocols that focus on a limited number of environmental values, rather than adopting a long-term, holistic view of development over time and space. Community-based environmental monitoring (CBEM) is emerging as a way to meaningfully include local Aboriginal citizens in the decision-making process as well as the assessment of the long-term impacts of the development of natural resources. We exploredmore » opportunities and barriers for developing CBEM programs that meet the needs of small and rural Aboriginal communities that are faced with the rapid and wide-spread development of natural resources. We conducted interviews with a local Aboriginal community, and natural resource management practitioners who could provide perspectives on the application of CBEM to resource management in north-central British Columbia, Canada. Results demonstrate that CBEM offers a locally adapted and culturally appropriate approach to facilitate the participation of Aboriginal communities in natural resource decision making and management. The interpretation of the specific role and purpose of CBEM differed among participants, depending on their objectives for and concerns about natural resource development. However, all parties were consistent in viewing CBEM as an effective method for engaging in dialogue, cooperation, and tracking environmental change. The development or improvement of CBEM programs should consider the efficacy of monitoring protocols, social cohesion and relationships, ability to inform decision-making, and effectiveness of CBEM for the members of the community. - Highlights: • We explored how to develop effective CBEM with a focus on Aboriginal communities. • We

Knowledge, attitudes, and practice behaviors of oncology advanced practice nurses regarding advanced care planning for patients with cancer.

PubMed

Zhou, Guiyun; Stoltzfus, Jill C; Houldin, Arlene D; Parks, Susan M; Swan, Beth Ann

2010-11-01

To establish initial reliability and validity of a Web-based survey focused on oncology advanced practice nurses' (APNs') knowledge, attitudes, and practice behaviors regarding advanced care planning, and to obtain preliminary understanding of APNs' knowledge, attitudes, and practice behaviors and perceived barriers to advanced care planning. Descriptive, cross-sectional, pilot survey study. The eastern United States. 300 oncology APNs. Guided by the Theory of Planned Behavior, a knowledge, attitudes, and practice behaviors survey was developed and reviewed for content validity. The survey was distributed to 300 APNs via e-mail and sent again to the 89 APNs who responded to the initial survey. Exploratory factor analysis was used to examine the construct validity and test-retest reliability of the survey's attitudinal and practice behavior portions. Respondents' demographics, knowledge, attitudes, practice behaviors, and perceived barriers to advanced care planning practice. Exploratory factor analysis yielded a five-factor solution from the survey's attitudes and practice behavior portions with internal consistency using Cronbach alpha. Respondents achieved an average of 67% correct answers in the 12-item knowledge section and scored positively in attitudes toward advanced care planning. Their practice behavior scores were marginally positive. The most common reported barriers were from patients' and families' as well as physicians' reluctance to discuss advanced care planning. The attitudinal and practice behaviors portions of the survey demonstrated preliminary construct validity and test-retest reliability. Regarding advanced care planning, respondents were moderately knowledgeable, but their advanced care planning practice was not routine. Validly assessing oncology APNs' knowledge, attitudes, and practice behaviors regarding advanced care planning will enable more tailored approaches to improve end-of-life care outcomes.

Environmental factors: opportunities and barriers for physical activity, and healthy eating among children and adolescents.

PubMed

Huybrechts, I; De Bourdeaudhuij, I; De Henauw, S

2010-01-01

While genetic factors play a role in the development of obesity, the dramatic increase of its prevalence in the past years strongly suggests that environmental factors are largely responsible. The wealth and variety of food supply available 24h/day and throughout the year, the change in dietary habits due to time constraints and the change in physical activity due to technological advances all create a 'toxic' environment responsible for obesity and eating habit disorders. This manuscript describes and discusses the results of a systematic review of environmental opportunities & obstacles for physical activity and dietary intake influencing the obesity epidemic among children and adolescents. Although evidence clearly shows the impact of the environment on obesity related lifestyle factors, evidence for effective strategies combating this obesogenic environment is very scarce. Interventions aiming to change environmental factors in order to reduce obesity may include taxes/subsidies encouraging healthy eating or physical activity, extra provision of sporting facilities, efforts to improve safety and accessibility of walking, cycling or play areas or attempting to influence social meanings/values attached to weight, food or physical activity. It is clear that some level of institutionalization of systems that support the desired changes is required to sustain environmental and social changes in the long-term. At last, it is important to note that better-designed and -conducted research on the true importance of the interaction between environmental factors and psychosocial factors, including the micro- and the macro-level, for obesogenic behavioral change is needed to reassure the success of large-scale environmental change interventions.

The dragons of inaction: psychological barriers that limit climate change mitigation and adaptation.

PubMed

Gifford, Robert

2011-01-01

Most people think climate change and sustainability are important problems, but too few global citizens engaged in high-greenhouse-gas-emitting behavior are engaged in enough mitigating behavior to stem the increasing flow of greenhouse gases and other environmental problems. Why is that? Structural barriers such as a climate-averse infrastructure are part of the answer, but psychological barriers also impede behavioral choices that would facilitate mitigation, adaptation, and environmental sustainability. Although many individuals are engaged in some ameliorative action, most could do more, but they are hindered by seven categories of psychological barriers, or "dragons of inaction": limited cognition about the problem, ideological world views that tend to preclude pro-environmental attitudes and behavior, comparisons with key other people, sunk costs and behavioral momentum, discredence toward experts and authorities, perceived risks of change, and positive but inadequate behavior change. Structural barriers must be removed wherever possible, but this is unlikely to be sufficient. Psychologists must work with other scientists, technical experts, and policymakers to help citizens overcome these psychological barriers.

Environmental Barrier Coating (EBC) Durability Modeling; An Overview and Preliminary Analysis

NASA Technical Reports Server (NTRS)

Abdul-Aziz, A.; Bhatt, R. T.; Grady, J. E.; Zhu, D.

2012-01-01

A study outlining a fracture mechanics based model that is being developed to investigate crack growth and spallation of environmental barrier coating (EBC) under thermal cycling conditions is presented. A description of the current plan and a model to estimate thermal residual stresses in the coating and preliminary fracture mechanics concepts for studying crack growth in the coating are also discussed. A road map for modeling life and durability of the EBC and the results of FEA model(s) developed for predicting thermal residual stresses and the cracking behavior of the coating are generated and described. Further initial assessment and preliminary results showed that developing a comprehensive EBC life prediction model incorporating EBC cracking, degradation and spalling mechanism under stress and temperature gradients typically seen in turbine components is difficult. This is basically due to mismatch in thermal expansion difference between sub-layers of EBC as well as between EBC and substrate, diffusion of moisture and oxygen though the coating, and densification of the coating during operating conditions as well as due to foreign object damage, the EBC can also crack and spall from the substrate causing oxidation and recession and reducing the design life of the EBC coated substrate.

Integrating knowledge across domains to advance the science of health behavior: overcoming challenges and facilitating success.

PubMed

Klein, William M P; Grenen, Emily G; O'Connell, Mary; Blanch-Hartigan, Danielle; Chou, Wen-Ying Sylvia; Hall, Kara L; Taber, Jennifer M; Vogel, Amanda L

2017-03-01

Health behaviors often co-occur and have common determinants at multiple levels (e.g., individual, relational, environmental). Nevertheless, research programs often examine single health behaviors without a systematic attempt to integrate knowledge across behaviors. This paper highlights the significant potential of cross-cutting behavioral research to advance our understanding of the mechanisms and causal factors that shape health behaviors. It also offers suggestions for how researchers could develop more effective interventions. We highlight barriers to such an integrative science along with potential steps that can be taken to address these barriers. With a more nuanced understanding of health behavior, redundancies in research can be minimized, and a stronger evidence base for the development of health behavior interventions can be realized.

Surface Cracking and Interface Reaction Associated Delamination Failure of Thermal and Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Eldridge, Jeffrey I.; Lee, Kang N.; Miller, Robert A.

2003-01-01

In this paper, surface cracking and interface reactions of a BSAS coating and a multi-layer ZTO2-8wt%Y2O3 and mullite/BSAS/Si thermal and environmental barrier coating system on SiC/SiC ceramic matrix composites were characterized after long-term combined laser thermal gradient and furnace cyclic tests in a water vapor containing environment. The surface cracking was analyzed based on the coating thermal gradient sintering behavior and thermal expansion mismatch stress characteristics under the thermal cyclic conditions. The interface reactions, which were largely enhanced by the coating surface cracking in the water vapor environment, were investigated in detail, and the reaction phases were identified for the coating system after the long- term exposure. The accelerated coating delamination failure was attributed to the increased delamination driving force under the thermal gradient cyclic loading and the reduced interface adhesion due to the detrimental interface reactions.

Methods for Quantification of Soil-Transmitted Helminths in Environmental Media: Current Techniques and Recent Advances.

PubMed

Collender, Philip A; Kirby, Amy E; Addiss, David G; Freeman, Matthew C; Remais, Justin V

2015-12-01

Limiting the environmental transmission of soil-transmitted helminths (STHs), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost-effective methods to detect and quantify STHs in the environment. We review the state-of-the-art of STH quantification in soil, biosolids, water, produce, and vegetation with regard to four major methodological issues: environmental sampling; recovery of STHs from environmental matrices; quantification of recovered STHs; and viability assessment of STH ova. We conclude that methods for sampling and recovering STHs require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Barriers and Biases toward Women: Impediments to Administrative Progression.

ERIC Educational Resources Information Center

Fobbs, Joan.

Barriers to administrative advancement for women in academe are discussed. A study of perceived managerial style and leadership skill of women two-year college presidents was designed to fill a gap in research during an era of significant advancement opportunities for women. Leadership in higher education in the United States is gradually…

Impact of volume and surface processes on the pre-ionization of dielectric barrier discharges: advanced diagnostics and fluid modeling

NASA Astrophysics Data System (ADS)

Nemschokmichal, Sebastian; Tschiersch, Robert; Höft, Hans; Wild, Robert; Bogaczyk, Marc; Becker, Markus M.; Loffhagen, Detlef; Stollenwerk, Lars; Kettlitz, Manfred; Brandenburg, Ronny; Meichsner, Jürgen

2018-05-01

The phenomenology and breakdown mechanism of dielectric barrier discharges are strongly determined by volume and surface memory effects. In particular, the pre-ionization provided by residual species in the volume or surface charges on the dielectrics influences the breakdown behavior of filamentary and diffuse discharges. This was investigated by advanced diagnostics such as streak camera imaging, laser photodetachment of negative ions and laser photodesorption of electrons from dielectric surfaces in correlation with 1D fluid modeling. The streak camera images show that an increasing number of residual charges in the volume changes the microdischarge breakdown in air-like gas mixtures from a cathode-directed streamer to a simultaneous propagation of cathode- and anode-directed streamers. In contrast, seed electrons are important for the pre-ionization if the density of residual charges in the volume is low. One source of seed electrons are negative ions, whose density exceeds the electron density during the pre-phase of diffuse helium-oxygen barrier discharges as indicated by the laser photodetachment experiments. Electrons desorbed from the cathodic dielectric have an even larger influence. They induce a transition from the glow-like to the Townsend-like discharge mode in nominally pure helium. Apart from analyzing the importance of the pre-ionization for the breakdown mechanism, the opportunities for manipulating the lateral structure and discharge modes are discussed. For this purpose, the intensity and diameter of a diffuse discharge in helium are controlled by an illuminated semiconducting barrier. Contribution to the Topical Issue "Fundamentals of Complex Plasmas", edited by Jürgen Meichsner, Michael Bonitz, Holger Fehske, Alexander Piel.

Barriers Facing Physicians Practicing Evidence-Based Medicine in Saudi Arabia

ERIC Educational Resources Information Center

Al-Almaie, Sameeh M.; Al-Baghli, Nadira

2004-01-01

Introduction: Tremendous advances in health care have been made through the development of evidence-based medicine (EBM). Studies show that physicians face barriers in practice, preventing the effective use of the best evidence available. Insight into these barriers should pave the way for an action plan to remove them. The aim of this study was…

Thick thermal barrier coatings for diesel engines

NASA Technical Reports Server (NTRS)

Beardsley, M. B.

1995-01-01

Caterpillar's approach to applying Thick Thermal Barrier Coatings (TTBC's) to diesel engine combustion chambers has been to use advanced modeling techniques to predict engine conditions and combine this information with fundamental property evaluation of TTBC systems to predict engine performance and TTBC stress states. Engine testing has been used to verify the predicted performance of the TTBC systems and provide information on failure mechanisms. The objective of Caterpillar's subcontract with ORNL is to advance the fundamental understanding of thick thermal barrier coating systems. Previous reviews of thermal barrier coating technology concluded that the current level of understanding of coating system behavior is inadequate and the lack of fundamental understanding may impede the application of TTBC's to diesel engines. Areas of TTBC technology being examined in this program include powder characteristics and chemistry; bond coat composition; coating design, microstructure, and thickness as they affect properties, durability, and reliability; and TTBC 'aging' effects (microstructural and property changes) under diesel engine operating conditions. Methods to evaluate the reliability and durability of TTBC's have been developed that attempt to understand the fundamental strength of TTBC's for particular stress states.

Thick thermal barrier coatings for diesel engines

NASA Technical Reports Server (NTRS)

Beardsley, M. Brad

1995-01-01

Caterpillar's approach to applying thick thermal barrier coatings (TTBC's) to diesel engine combustion chambers has been to use advanced modeling techniques to predict engine conditions and combine this information with fundamental property evaluation of TTBC systems to predict engine performance and TTBC stress states. Engine testing has been used to verify the predicted performance of the TTBC systems and provide information on failure mechanisms. The objective Caterpillar's program to date has been to advance the fundamental understanding of thick thermal barrier coating systems. Previous reviews of thermal barrier coating technology concluded that the current level of understanding of coating system behavior is inadequate and the lack of fundamental understanding may impeded the application of TTBC's to diesel engines. Areas of TTBC technology being examined in this program include powder characteristics and chemistry; bond coat composition; coating design, microstructure, and thickness as they affect properties, durability, and reliability; and TTBC 'aging' effects (microstructural and property changes) under diesel engine operating conditions. Methods to evaluate the reliability and durability of TTBC's have been developed that attempt to understand the fundamental strength of TTBC's for particular stress states.

Barriers and Bias Hold Back Women in Academic Science

NASA Astrophysics Data System (ADS)

Zielinski, Sarah

2006-09-01

Underlying biases and discrimination resultin barriers that prevent women in science andengineering from advancing in academicpositions, according to an 18 September reportfrom the U.S. National Academies.

Ceramic technology for advanced heat engines project. Semiannual progress report, April-September 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-05-01

An assessment of needs was completed, and a five-year project plan was developed with input from private industry. Objective is to develop the industrial technology base required for reliable ceramics for application in advanced automotive heat engines. Focus is on structural ceramics for advanced gas turbine and diesel engines, ceramic bearings and attachments, and ceramic coatings for thermal barrier and wear applications in these engines. The work described in this report is organized according to the following WBS project elements: management and coordination; materials and processing (monolithics, ceramic composites, thermal and wear coatings, joining); materials design methodology (contact interfaces, newmore » concepts); data base and life prediction (time-dependent behavior, environmental effects, fracture mechanics, NDE development); and technology transfer. This report includes contributions from all currently active project participants.« less

Alternating-Composition Layered Ceramic Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Zhu, Dongming

2008-01-01

Ceramic thermal and environmental barrier coatings (T/EBCs) that contain multiple layers of alternating chemical composition have been developed as improved means of protecting underlying components of gas-turbine and other heat engines against both corrosive combustion gases and high temperatures.

Openly Published Environmental Sensing (OPEnS) | Advancing Open-Source Research, Instrumentation, and Dissemination

NASA Astrophysics Data System (ADS)

Udell, C.; Selker, J. S.

2017-12-01

The increasing availability and functionality of Open-Source software and hardware along with 3D printing, low-cost electronics, and proliferation of open-access resources for learning rapid prototyping are contributing to fundamental transformations and new technologies in environmental sensing. These tools invite reevaluation of time-tested methodologies and devices toward more efficient, reusable, and inexpensive alternatives. Building upon Open-Source design facilitates community engagement and invites a Do-It-Together (DIT) collaborative framework for research where solutions to complex problems may be crowd-sourced. However, barriers persist that prevent researchers from taking advantage of the capabilities afforded by open-source software, hardware, and rapid prototyping. Some of these include: requisite technical skillsets, knowledge of equipment capabilities, identifying inexpensive sources for materials, money, space, and time. A university MAKER space staffed by engineering students to assist researchers is one proposed solution to overcome many of these obstacles. This presentation investigates the unique capabilities the USDA-funded Openly Published Environmental Sensing (OPEnS) Lab affords researchers, within Oregon State and internationally, and the unique functions these types of initiatives support at the intersection of MAKER spaces, Open-Source academic research, and open-access dissemination.

Evaluation of a permeable reactive barrier technology for use at Rocky Flats Environmental Technology Site (RFETS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

DWYER,BRIAN P.

2000-01-01

Three reactive materials were evaluated at laboratory scale to identify the optimum treatment reagent for use in a Permeable Reactive Barrier Treatment System at Rocky Flats Environmental Technology Site (RFETS). The contaminants of concern (COCS) are uranium, TCE, PCE, carbon tetrachloride, americium, and vinyl chloride. The three reactive media evaluated included high carbon steel iron filings, an iron-silica alloy in the form of a foam aggregate, and a peculiar humic acid based sorbent (Humasorb from Arctech) mixed with sand. Each material was tested in the laboratory at column scale using simulated site water. All three materials showed promise for themore » 903 Mound Site however, the iron filings were determined to be the least expensive media. In order to validate the laboratory results, the iron filings were further tested at a pilot scale (field columns) using actual site water. Pilot test results were similar to laboratory results; consequently, the iron filings were chosen for the fill-scale demonstration of the reactive barrier technology. Additional design parameters including saturated hydraulic conductivity, treatment residence time, and head loss across the media were also determined and provided to the design team in support of the final design. The final design was completed by the Corps of Engineers in 1997 and the system was constructed in the summer of 1998. The treatment system began fill operation in December, 1998 and despite a few problems has been operational since. Results to date are consistent with the lab and pilot scale findings, i.e., complete removal of the contaminants of concern (COCs) prior to discharge to meet RFETS cleanup requirements. Furthermore, it is fair to say at this point in time that laboratory developed design parameters for the reactive barrier technology are sufficient for fuel scale design; however,the treatment system longevity and the long-term fate of the contaminants are questions that remain unanswered

Barriers to applying advanced high-temperature materials

NASA Astrophysics Data System (ADS)

Premkumar, M. K.

1993-01-01

During the past 25 years, aerospace engineers and material scientists have made significant technical progress toward developing next-generation aircraft. However, while advanced high-temperature materials continue to be developed, the outlook for their future application is uncertain and will depend on the ability of these materials to satisfy a more diverse market.

The Truth, the Whole Truth, and Nothing but the Ground-Truth: Methods to Advance Environmental Justice and Researcher-Community Partnerships

ERIC Educational Resources Information Center

Sadd, James; Morello-Frosch, Rachel; Pastor, Manuel; Matsuoka, Martha; Prichard, Michele; Carter, Vanessa

2014-01-01

Environmental justice advocates often argue that environmental hazards and their health effects vary by neighborhood, income, and race. To assess these patterns and advance preventive policy, their colleagues in the research world often use complex and methodologically sophisticated statistical and geospatial techniques. One way to bridge the gap…

Great Barrier Reef

NASA Image and Video Library

2017-12-08

Great Barrier Reef - August 8th, 1999 Description: What might be mistaken for dinosaur bones being unearthed at a paleontological dig are some of the individual reefs that make up the Great Barrier Reef, the world's largest tropical coral reef system. The reef stretches more than 2,000 kilometers (1,240 miles) along the coast of Queensland, Australia. It supports astoundingly complex and diverse communities of marine life and is the largest structure on the planet built by living organisms. Credit: USGS/NASA/Landsat 7 To learn more about the Landsat satellite go to: landsat.gsfc.nasa.gov/ NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Learning Center for Advancing Natural Resources and Environmental Sustainability in the Mexican State of Jalisco

Treesearch

Celedonio Aguirre-Bravo; Hans Schreuder

2006-01-01

This paper addresses the need and opportunity for creating a learning center for advancing the monitoring and assessment of ecosystems resources and their sustainability in the Mexican state of Jalisco. It is an initiative that responds to the growing needs of a more sophisticated world in which knowledge is the tool for creating social and environmental progress and...

Surface Cracking and Interface Reaction Associated Delamination Failure of Thermal and Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Choi, Sung R.; Eldridge, Jeffrey I.; Lee, Kang N.; Miller, Robert A.

2003-01-01

In this paper, surface cracking and interface reactions of a BSAS coating and a multi-layer ZrO2-8wt%Y2O3 and mullite/BSAS/Si thermal and environmental barrier coating system on SiC/SiC ceramic matrix composites were characterized after long-term combined laser thermal gradient and furnace cyclic tests in a water vapor containing environment. The surface cracking was analyzed based on the coating thermal gradient sintering behavior and thermal expansion mismatch stress characteristics under the thermal cyclic conditions. The interface reactions, which were largely enhanced by the coating surface cracking in the water vapor environment, were investigated in detail, and the reaction phases were identified for the coating system after the long-term exposure. The accelerated coating delamination failure was attributed to the increased delamination driving force under the thermal gradient cyclic loading and the reduced interface adhesion due to the detrimental interface reactions.

Silicon based substrate with calcium aluminosilicate environmental/thermal barrier layer

NASA Technical Reports Server (NTRS)

Eaton, Jr., Harry Edwin (Inventor); Allen, William Patrick (Inventor); Miller, Robert Alden (Inventor); Jacobson, Nathan S. (Inventor); Smialek, James L. (Inventor); Opila, Elizabeth J. (Inventor); Lee, Kang N. (Inventor); Nagaraj, Bangalore A. (Inventor); Wang, Hongyu (Inventor); Meschter, Peter Joel (Inventor)

2001-01-01

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate.

Nested barriers to low-carbon infrastructure investment

NASA Astrophysics Data System (ADS)

Granoff, Ilmi; Hogarth, J. Ryan; Miller, Alan

2016-12-01

Low-carbon, 'green' economic growth is necessary to simultaneously improve human welfare and avoid the worst impacts of climate change and environmental degradation. Infrastructure choices underpin both the growth and the carbon intensity of the economy. This Perspective explores the barriers to investing in low-carbon infrastructure and some of the policy levers available to overcome them. The barriers to decarbonizing infrastructure 'nest' within a set of barriers to infrastructure development more generally that cause spending on infrastructure--low-carbon or not--to fall more than 70% short of optimal levels. Developing countries face additional barriers such as currency and political risks that increase the investment gap. Low-carbon alternatives face further barriers, such as commercialization risk and financial and public institutions designed for different investment needs. While the broader barriers to infrastructure investment are discussed in other streams of literature, they are often disregarded in literature on renewable energy diffusion or climate finance, which tends to focus narrowly on the project costs of low- versus high-carbon options. We discuss how to overcome the barriers specific to low-carbon infrastructure within the context of the broader infrastructure gap.

Neighborhood walking among overweight and obese adults: age variations in barriers and motivators.

PubMed

Lee, Chanam; Ory, Marcia G; Yoon, Jeongjae; Forjuoh, Samuel N

2013-02-01

Walking is a popular form of physical activity that can bring many public health benefits. It can be even more beneficial to those who are currently obese or overweight. However, many barriers discourage people from walking, ranging from lack of motivation to unsafe neighborhood environments, and such barriers vary with age. This study addresses barriers and motivators to walking among overweight and obese adults, and examines their age variations. Particular emphasis was given to modifiable environmental factors as the priority intervention targets. A survey of 161 overweight and obese adults recruited from a large integrated healthcare system in central Texas provided data on walking, demographics, motivators and barriers. Descriptive statistics and correlation analysis were conducted. The respondents had a mean age of 48.4 (20-86), and were predominantly female (80.8%), non-Hispanic White (86.0%), and obese (mean BMI = 32.5). Popular environmental barriers to walking were: bad weather, inadequate lighting, no shade, unattended dogs, disconnected sidewalks, poor walking surfaces, no interesting places to walk nearby, and no benches (74.5-38.5%). Even and smooth walking surfaces and benches were more frequently reported by older adults as motivators. Proximity to recreational facilities was a stronger motivator for younger adults. Two safety related barriers, fear of injury (older adults) and traffic safety concerns (younger adults), also showed significant age differences. Overweight and obese adults experience substantial environmental barriers to walking, but many of them are modifiable. Observed age variations suggest that future interventions may be more effective if tailored to address age-specific barriers.

Big Data breaking barriers - first steps on a long trail

NASA Astrophysics Data System (ADS)

Schade, S.

2015-04-01

Most data sets and streams have a geospatial component. Some people even claim that about 80% of all data is related to location. In the era of Big Data this number might even be underestimated, as data sets interrelate and initially non-spatial data becomes indirectly geo-referenced. The optimal treatment of Big Data thus requires advanced methods and technologies for handling the geospatial aspects in data storage, processing, pattern recognition, prediction, visualisation and exploration. On the one hand, our work exploits earth and environmental sciences for existing interoperability standards, and the foundational data structures, algorithms and software that are required to meet these geospatial information handling tasks. On the other hand, we are concerned with the arising needs to combine human analysis capacities (intelligence augmentation) with machine power (artificial intelligence). This paper provides an overview of the emerging landscape and outlines our (Digital Earth) vision for addressing the upcoming issues. We particularly request the projection and re-use of the existing environmental, earth observation and remote sensing expertise in other sectors, i.e. to break the barriers of all of these silos by investigating integrated applications.

A comparison of freeway median crash frequency, severity, and barrier strike outcomes by median barrier type.

PubMed

Russo, Brendan J; Savolainen, Peter T

2018-08-01

Median-crossover crashes are among the most hazardous events that can occur on freeways, often resulting in severe or fatal injuries. The primary countermeasure to reduce the occurrence of such crashes is the installation of a median barrier. When installation of a median barrier is warranted, transportation agencies are faced with the decision among various alternatives including concrete barriers, beam guardrail, or high-tension cable barriers. Each barrier type differs in terms of its deflection characteristics upon impact, the required installation and maintenance costs, and the roadway characteristics (e.g., median width) where installation would be feasible. This study involved an investigation of barrier performance through an in-depth analysis of crash frequency and severity data from freeway segments where high-tension cable, thrie-beam, and concrete median barriers were installed. A comprehensive manual review of crash reports was conducted to identify crashes in which a vehicle left the roadway and encroached into the median. This review also involved an examination of crash outcomes when a barrier strike occurred, which included vehicle containment, penetration, or re-direction onto the travel lanes. The manual review of crash reports provided critical supplementary information through narratives and diagrams not normally available through standard fields on police crash report forms. Statistical models were estimated to identify factors that affect the frequency, severity, and outcomes of median-related crashes, with particular emphases on differences between segments with varying median barrier types. Several roadway-, traffic-, and environmental-related characteristics were found to affect these metrics, with results varying across the different barrier types. The results of this study provide transportation agencies with important guidance as to the in-service performance of various types of median barrier. Copyright © 2018 Elsevier Ltd. All rights

Kinetic Monte Carlo Simulations of Diffusion in Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

Good, Brian

2017-01-01

Ceramic Matrix Components (CMC) components for use in turbine engines offer a number of advantages compared with current practice. However, such components are subject to degradation through a variety of mechanisms. In particular, in the hot environment inside a turbine in operation a considerable amount of water vapor is present, and this can lead to corrosion and recession. Environmental Barrier Coating (EBC) systems that limit the amount of oxygen and water reaching the component are required to reduce this degradation and extend component life. A number of silicate-based materials are under consideration for use in such coating systems, including Yttterbium and Yttrium di- and monosilicates. In this work, we present results of kinetic Monte Carlo computer simulations of oxygen diffusion in Yttrium disilicate, and compare with previous work on Yttterbium disilicate. Coatings may also exhibit cracking, and the cracks can provide a direct path for oxygen to reach the component. There is typically a bond coat between the coating and component surface, but the bond coat material is generally chosen for properties other than low oxygen diffusivity. Nevertheless, the degree to which the bond coat can inhibit oxygen diffusion is of interest, as it may form the final defense against oxygen impingement on the component. We have therefore performed similar simulations of oxygen diffusion through HfSiO4, a proposed bond coat material.

Barriers to performing stretching exercises among Korean-Chinese female migrant workers in Korea.

PubMed

Lee, Hyeonkyeong; Wilbur, JoEllen; Chae, Duckhee; Lee, Kyongeun; Lee, Meenhye

2015-01-01

The purpose of this study was to investigate the barriers to performing stretching exercise experienced by Korean-Chinese female migrant workers during a community-based 12-week stretching exercise intervention trial. Qualitative secondary data analysis was conducted using telephone counseling interview transcripts from 27 middle-aged, Korean-Chinese migrant women workers. A semistructured interview question asking barriers to performing stretching exercise was given to women who did not adhere to recommended stretching exercise. During the 12-week home-based stretching exercise intervention trial, six telephone calls were made to participants biweekly to elicit barriers to performing stretching exercise. Directed content analysis approach was utilized using three barrier categories: intrapersonal, interpersonal, and work-related environmental factors based on the ecological model. Participants experienced an average of 2.5 barriers during the study period. Intrapersonal barriers included lack of time and lack of motivation, and interpersonal barriers included no family to provide support and also a feeling resistance from coworkers. Work-related environmental barriers included frequent job changes, long working hours, lack of rest time, and unpredictable job demands. The findings highlight that migrant workers in Korea face unique work-related difficulties which present barriers to exercise. © 2014 Wiley Periodicals, Inc.

Purpose, Processes, Partnerships, and Products: 4Ps to advance Participatory Socio-Environmental Modeling

NASA Astrophysics Data System (ADS)

Gray, S. G.; Voinov, A. A.; Jordan, R.; Paolisso, M.

2016-12-01

Model-based reasoning is a basic part of human understanding, decision-making, and communication. Including stakeholders in environmental model building and analysis is an increasingly popular approach to understanding environmental change since stakeholders often hold valuable knowledge about socio-environmental dynamics and since collaborative forms of modeling produce important boundary objects used to collectively reason about environmental problems. Although the number of participatory modeling (PM) case studies and the number of researchers adopting these approaches has grown in recent years, the lack of standardized reporting and limited reproducibility have prevented PM's establishment and advancement as a cohesive field of study. We suggest a four dimensional framework that includes reporting on dimensions of: (1) the Purpose for selecting a PM approach (the why); (2) the Process by which the public was involved in model building or evaluation (the how); (3) the Partnerships formed (the who); and (4) the Products that resulted from these efforts (the what). We highlight four case studies that use common PM software-based approaches (fuzzy cognitive mapping, agent-based modeling, system dynamics, and participatory geospatial modeling) to understand human-environment interactions and the consequences of environmental changes, including bushmeat hunting in Tanzania and Cameroon, agricultural production and deforestation in Zambia, and groundwater management in India. We demonstrate how standardizing communication about PM case studies can lead to innovation and new insights about model-based reasoning in support of environmental policy development. We suggest that our 4P framework and reporting approach provides a way for new hypotheses to be identified and tested in the growing field of PM.

Housing accessibility for senior citizens in Sweden: Estimation of the effects of targeted elimination of environmental barriers.

PubMed

Pettersson, Cecilia; Slaug, Björn; Granbom, Marianne; Kylberg, Marianne; Iwarsson, Susanne

2017-01-24

To estimate the effects of targeted elimination of environmental barriers (EB) in the ordinary housing stock in Sweden, and to explore the estimated effects on accessibility at a population level in relation to (a) residents with different functional profiles, (b) different housing types and (c) building periods. Data on dwellings from existing Swedish research databases were utilized. EB and accessibility were assessed by means of the Housing Enabler instrument. In simulations of EB removal, five items that correspond to the most common housing adaptations were selected. The simulations were applied to four functional profiles of different complexity. EB known to be commonly removed by housing adaptations exist in large proportions of the existing ordinary housing stock. Estimated targeted elimination of selected barriers would have the largest accessibility effects for the more complex functional profiles. The effects would be consistently larger for one-family houses, and for all types of dwellings built before 1960. The elimination of the EB most commonly addressed by housing adaptations could result in a reduction of the housing accessibility problems that community-living older people are facing. For society to solve the housing situation for the ageing population well-informed and efficient upgrading of ordinary housing is imperative.

Evaluating environmental education, citizen science, and stewardship through naturalist programs.

PubMed

Merenlender, Adina M; Crall, Alycia W; Drill, Sabrina; Prysby, Michelle; Ballard, Heidi

2016-12-01

Amateur naturalists have played an important role in the study and conservation of nature since the 17th century. Today, naturalist groups make important contributions to bridge the gap between conservation science and practice around the world. We examined data from 2 regional naturalist programs to understand participant motivations, barriers, and perspectives as well as the actions they take to advance science, stewardship, and community engagement. These programs provide certification-based natural history and conservation science training for adults that is followed by volunteer service in citizen science, education, and stewardship. Studies in California and Virginia include quantitative and qualitative evaluation data collected through pre- and postcourse surveys, interviews, and long-term tracking of volunteer hours. Motivations of participants focused on learning about the local environment and plants and animals, connecting with nature, becoming certified, and spending time with people who have similar interests. Over half the participants surveyed were over 50 years old, two-thirds were women, and a majority reported household incomes of over $50,000 (60% in California, 85% in Virginia), and <20% of those surveyed in both states described themselves as nonwhite. Thus, these programs need to improve participation by a wider spectrum of the public. We interviewed younger and underrepresented adults to examine barriers to participation in citizen science. The primary barrier was lack of time due to the need to work and focus on career advancement. Survey data revealed that participants' ecological knowledge, scientific skills, and belief in their ability to address environmental issues increased after training. Documented conservation actions taken by the participants include invasive plant management, habitat restoration, and cleanups of natural areas and streams. Long-term data from Virginia on volunteer hours dedicated to environmental citizen science

Photocatalytic Degradation Effect of μ-Dielectric Barrier Discharge Plasma Treated Titanium Dioxide Nanoparticles on Environmental Contaminant.

PubMed

Seo, Hyeon Jin; Hwang, Ki-Hwan; Na, Young Hoon; Boo, Jin-Hyo

2018-09-01

This study focused on the photocatalytic degradation effect of the μ-dielectric barrier discharge (μ-DBD) plasma treated titanium dioxide (TiO2) nanoparticles on environmental contaminant such as formaldehyde. TiO2 nanoparticles were treated by a μ-DBD plasma source with nitrogen gas. We analyzed the degradation of formaldehyde with the plasma treated TiO2 nanoparticles by UV-visible spectrophotometer (UV-VIS), and demonstrated that the photocatalytic activity of the μ-DBD plasma-treated TiO2 nanoparticles showed significantly high catalytic efficiency rather than without plasma treated TiO2 nanoparticles. Field emission scanning electron microscopes (FE-SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle analyzer were used to measure the effects of photocatalytic degradation for the plasma treated TiO2 nanoparticles.

Spinal Cord Injuries in Wave-Riding Sports: The Influence of Environmental and Sport-Specific Factors.

PubMed

Falconi, Audrey; Flick, David; Ferguson, Jason; Glorioso, John E

2016-01-01

Spinal cord injury is a nonfatal, catastrophic consequence of wave-riding sports. With surfing at the core, a multitude of activities have evolved that attempt to harness the power of ocean waves. The unique qualities of each wave-riding sport, in combination with the environmental factors of the ocean, define the risk for potential injuries. As wave-riding sports have become more advanced, athletes continue to push physical barriers. Taller waves are attempted while incorporating aerial maneuvers, all without protective equipment.

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

EPA Pesticide Factsheets

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

Physical activity in Latinas: social and environmental influences

PubMed Central

Larsen, Britta A; Pekmezi, Dorothy; Marquez, Becky; Benitez, Tanya J; Marcus, Bess H

2013-01-01

Latinas are the largest, fastest growing female ethnic minority group in the USA, and also report the lowest levels of physical activity. Following the framework of the social ecological model, this review examines unique social and environmental factors that influence physical activity in Latinas. Research shows that Latinas receive little social support for activity despite having large, close-knit social networks. Interventions incorporating social support components are generally effcacious. Latinas also face many environmental barriers, including crime, heat, traffic, lack of facilities and a fear of immigration enforcement, and there have been few attempts to address environmental barriers in Latino communities. Successful future interventions will need to consider unique social and environmental barriers affecting Latinas, and help Latinas learn to incorporate social networks into physical activity participation. PMID:23477325

Coherent anti-Stokes Raman scattering microscopy: overcoming technical barriers for clinical translation

PubMed Central

Tu, Haohua; Boppart, Stephen A.

2015-01-01

Clinical translation of coherent anti-Stokes Raman scattering microscopy is of great interest because of the advantages of noninvasive label-free imaging, high sensitivity, and chemical specificity. For this to happen, we have identified and review the technical barriers that must be overcome. Prior investigations have developed advanced techniques (features), each of which can be used to effectively overcome one particular technical barrier. However, the implementation of one or a small number of these advanced features in previous attempts for clinical translation has often introduced more tradeoffs than benefits. In this review, we outline a strategy that would integrate multiple advanced features to overcome all the technical barriers simultaneously, effectively reduce tradeoffs, and synergistically optimize CARS microscopy for clinical translation. The operation of the envisioned system incorporates coherent Raman micro-spectroscopy for identifying vibrational biomolecular markers of disease and single-frequency (or hyperspectral) Raman imaging of these specific biomarkers for real-time in vivo diagnostics and monitoring. An optimal scheme of clinical CARS micro-spectroscopy for thin ex vivo tissues. PMID:23674234

Barriers impacting the utilization of supervision techniques in genetic counseling.

PubMed

Masunga, Abigail; Wusik, Katie; He, Hua; Yager, Geoffrey; Atzinger, Carrie

2014-12-01

Clinical supervision is an essential element in training genetic counselors. Although live supervision has been identified as the most common supervision technique utilized in genetic counseling, there is limited information on factors influencing its use as well as the use of other techniques. The purpose of this study was to identify barriers supervisors face when implementing supervision techniques. All participants (N = 141) reported utilizing co-counseling. This was most used with novice students (96.1%) and intermediate students (93.7%). Other commonly used techniques included live supervision where the supervisor is silent during session (98.6%) which was used most frequently with advanced students (94.0%), and student self-report (64.7%) used most often with advanced students (61.2%). Though no barrier to these commonly used techniques was identified by a majority of participants, the most frequently reported barriers included time and concern about patient's welfare. The remaining supervision techniques (live remote observation, video, and audio recording) were each used by less than 10% of participants. Barriers that significantly influenced use of these techniques included lack of facilities/equipment and concern about patient reactions to technique. Understanding barriers to implementation of supervisory techniques may allow students to be efficiently trained in the future by reducing supervisor burnout and increasing the diversity of techniques used.

Environmental assessment of different advanced oxidation processes applied to a bleaching Kraft mill effluent.

PubMed

Muñoz, Iván; Rieradevall, Joan; Torrades, Francesc; Peral, José; Domènech, Xavier

2006-01-01

Different advanced oxidation processes (AOPs) have been applied to remove the organic carbon content of a paper mill effluent originating from the Kraft pulp bleaching process. The considered AOPs were: TiO(2)-mediated heterogeneous photocatalysis, TiO(2)-mediated heterogeneous photocatalysis assisted with H(2)O(2), TiO(2)-mediated heterogeneous photocatalysis coupled with Fenton, photo-Fenton, ozonation and ozonation with UV-A light irradiation. The application of the selected AOPs all resulted in a considerable decrease in dissolved organic carbon (DOC) content with variable treatment efficiencies depending upon the nature/type of the applied AOP. A Life Cycle Assessment (LCA) study was used as a tool to compare the different AOPs in terms of their environmental impact. Heterogeneous photocatalysis coupled with the Fenton's reagent proved to have the lowest environmental impact accompanied with a moderate-to-high DOC removal rate. On the other hand, heterogeneous photocatalysis appeared to be the worst AOP both in terms of DOC abatement rate and environmental impact. For the studied AOPs, LCA has indicated that the environmental impact was attributable to the high electrical energy (power) consumption necessary to run a UV-A lamp or to produce ozone.

Kinetic Monte Carlo Simulations of Oxygen Diffusion in Environmental Barrier Coating Materials

NASA Technical Reports Server (NTRS)

Good, Brian S.

2017-01-01

Ceramic Matrix Composite (CMC) materials are of interest for use in next-generation turbine engine components, offering a number of significant advantages, including reduced weight and high operating temperatures. However, in the hot environment in which such components operate, the presence of water vapor can lead to corrosion and recession, limiting the useful life of the components. Such degradation can be reduced through the use of Environmental Barrier Coatings (EBCs) that limit the amount of oxygen and water vapor reaching the component. Candidate EBC materials include Yttrium and Ytterbium silicates. In this work we present results of kinetic Monte Carlo (kMC) simulations of oxygen diffusion, via the vacancy mechanism, in Yttrium and Ytterbium disilicates, along with a brief discussion of interstitial diffusion. An EBC system typically includes a bond coat located between the EBC and the component surface. Bond coat materials are generally chosen for properties other than low oxygen diffusivity, but low oxygen diffusivity is nevertheless a desirable characteristic, as the bond coat could provide some additional component protection, particularly in the case where cracks in the coating system provide a direct path from the environment to the bond coat interface. We have therefore performed similar kMC simulations of oxygen diffusion in this material.

Overexpanded viscous supersonic jet interacting with a unilateral barrier

NASA Astrophysics Data System (ADS)

Dobrynin, B. M.; Maslennikov, V. G.; Sakharov, V. A.; Serova, E. V.

1986-07-01

The interaction of a two-dimensional supersonic jet with a unilateral barrier parallel to the flow symmetry plane was studied to account for effects due to gas viscosity and backgound-gas ejection from the region into which the jet expands. In the present experiments, the incident shock wave was reflected at the end of a shock tube equipped with a nozzle. The jet emerged into a pressure chamber 6 cu m in volume and the environmental pressure ratio of the flow in the quasi-stationary phase remained constant. The light source was an OGM-20 laser operating in the giant-pulse mode. Due to background-gas ejection, the gas density in the vicinity of the barrier is much less than on the unconfined side of the jet. The resulting flow is characterized by two distinct environmental pressure ratios: the flow is underexpanded near the barrier, while on the other side it is overexpanded.

Barriers and Strategies for Success for American Indian College Students: A Review

ERIC Educational Resources Information Center

Keith, Jill F.; Stastny, Sherri N.; Brunt, Ardith

2016-01-01

American Indian and Alaska Native students have a significantly lower college graduation rate than that of other ethnic groups in the United States. These students often face a variety of barriers to the completion of their education. Overcoming barriers for the achievement of an advanced education takes commitment, hard work, and dedication on…

Machine Learning Technologies Translates Vigilant Surveillance Satellite Big Data into Predictive Alerts for Environmental Stressors

NASA Astrophysics Data System (ADS)

Johnson, S. P.; Rohrer, M. E.

2017-12-01

The application of scientific research pertaining to satellite imaging and data processing has facilitated the development of dynamic methodologies and tools that utilize nanosatellites and analytical platforms to address the increasing scope, scale, and intensity of emerging environmental threats to national security. While the use of remotely sensed data to monitor the environment at local and global scales is not a novel proposition, the application of advances in nanosatellites and analytical platforms are capable of overcoming the data availability and accessibility barriers that have historically impeded the timely detection, identification, and monitoring of these stressors. Commercial and university-based applications of these technologies were used to identify and evaluate their capacity as security-motivated environmental monitoring tools. Presently, nanosatellites can provide consumers with 1-meter resolution imaging, frequent revisits, and customizable tasking, allowing users to define an appropriate temporal scale for high resolution data collection that meets their operational needs. Analytical platforms are capable of ingesting increasingly large and diverse volumes of data, delivering complex analyses in the form of interpretation-ready data products and solutions. The synchronous advancement of these technologies creates the capability of analytical platforms to deliver interpretable products from persistently collected high-resolution data that meet varying temporal and geographic scale requirements. In terms of emerging environmental threats, these advances translate into customizable and flexible tools that can respond to and accommodate the evolving nature of environmental stressors. This presentation will demonstrate the capability of nanosatellites and analytical platforms to provide timely, relevant, and actionable information that enables environmental analysts and stakeholders to make informed decisions regarding the prevention

Advancing Environmental Health: A Ballroom Dance Between Human Health and Earth Sciences Research

NASA Astrophysics Data System (ADS)

Miller, A.

2016-12-01

The mission of the National Institute of Environmental Health Sciences (NIEHS) is to discover how the environment affects people in order to promote healthier lives. Translation of this mission into a meaningful reality entails extensive interdisciplinary interactions, expertise, and collaborations between the traditional health and earth sciences communities. Efforts to advance our understanding of adverse effects and illness associated with environmental factors requires not only a refined understanding of the biological mechanisms and pathways (e.g., inflammation, epigenetic changes, oxidative stress, mutagenesis, etc.) related to function and disease, but also the incredibly broad and complex environmental exposures and systems that influence these processes. Further complicating efforts to understand such interactions is the need to take into account individual susceptibility to disease across the human life span. While it is clear that environmental exposures can be readily linked to disease in individuals and to disproportionate health disparities in populations, the underlying risk factors for such findings are often elusive. Health and earth scientists have a long tradition of crossing their scientific divides to work together on a wide range of problems and issues, including disasters. Emergency situations, such as the environmental asbestos contamination in Libby, Montana, the Gulf Oil Spill, numerous chemical releases into air and water, wildfires, the World Trade Center Attack, and responses to Ebola, and now Zika, demand the collective expertise of the "environmental health sciences enterprise" to protect the public's health, facilitate recovery, and improve future preparedness. Furthermore, such high visibility efforts stand as a clear example of what human and earth sciences research can accomplish when transformative interdisciplinary approaches and a diverse well-trained cadre of scientists dance together on the ballroom floor.

[The blood-brain barrier in ageing persons].

PubMed

Haaning, Nina; Damsgaard, Else Marie; Moos, Torben

2018-03-26

Brain capillary endothelial cells (BECs) form the ultra-tight blood-brain barrier (BBB). The permeability of the BBB increases with increasing age and neurovascular and neurodegenerative diseases. Major defects of the BBB can be initiated by increased permeability to plasma proteins in small arteriosclerotic arteries and release of proteins from degenerating neurons into the brain extracellular space. These proteins deposit in perivascular spaces, and subsequently negatively influence the BECs leading to decreased expression of barrier proteins. Detection of BBB defects by the use of non-invasive techniques is relevant for clinical use in settings with advanced age and severe brain disorders.

Rural and Urban Living in Persons with Spinal Cord Injury and Comparing Environmental Barriers, Their Health, and Quality-of-Life Outcomes.

PubMed

Glennie, R Andrew; Batke, Juliet; Fallah, Nader; Cheng, Christiana L; Rivers, Carly S; Noonan, Vanessa K; Dvorak, Marcel F; Fisher, Charles G; Kwon, Brian K; Street, John T

2017-10-15

There is worldwide geographic variation in the epidemiology of traumatic spinal cord injury (tSCI). The aim of this study was to determine whether environmental barriers, health status, and quality-of-life outcomes differ between patients with tSCI living in rural or urban settings, and whether patients move from rural to urban settings after tSCI. A cohort review of the Rick Hansen SCI Registry (RHSCIR) was undertaken from 2004 to 2012 for one province in Canada. Rural/urban setting was determined using postal codes. Outcomes data at 1 year in the community included the Short Form-36 Version 2 (SF36v2™), Life Satisfaction Questionnaire, Craig Hospital Inventory of Environmental Factors-Short Form (CHIEF-SF), Functional Independent Measure ® Instrument, and SCI Health Questionnaire. Statistical methodologies used were t test, Mann-Whitney U test, and Fisher's exact or χ 2 test. In the analysis, 338 RHSCIR participants were included; 65 lived in a rural setting and 273 in an urban setting. Of the original patients residing in a rural area at discharge,10 moved to an urban area by 1 year. Those who moved from a rural to urban area reported a lower SF-36v2™ Mental Component Score (MCS; p = 0.04) and a higher incidence of depression at 1 year (p = 0.04). Urban patients also reported a higher incidence of depression (p = 0.02) and a lower CHIEF-SF total score (p = 0.01) indicating fewer environmental barriers. No significant differences were found in other outcomes. Results suggest that although the patient outcomes are similar, some patients move from rural to urban settings after tSCI. Future efforts should target screening mental health problems early, especially in urban settings.

Rural and Urban Living in Persons with Spinal Cord Injury and Comparing Environmental Barriers, Their Health, and Quality-of-Life Outcomes

PubMed Central

Batke, Juliet; Fallah, Nader; Cheng, Christiana L.; Rivers, Carly S.; Noonan, Vanessa K.; Dvorak, Marcel F.; Fisher, Charles G.; Kwon, Brian K.; Street, John T.

2017-01-01

Abstract There is worldwide geographic variation in the epidemiology of traumatic spinal cord injury (tSCI). The aim of this study was to determine whether environmental barriers, health status, and quality-of-life outcomes differ between patients with tSCI living in rural or urban settings, and whether patients move from rural to urban settings after tSCI. A cohort review of the Rick Hansen SCI Registry (RHSCIR) was undertaken from 2004 to 2012 for one province in Canada. Rural/urban setting was determined using postal codes. Outcomes data at 1 year in the community included the Short Form-36 Version 2 (SF36v2™), Life Satisfaction Questionnaire, Craig Hospital Inventory of Environmental Factors-Short Form (CHIEF-SF), Functional Independent Measure® Instrument, and SCI Health Questionnaire. Statistical methodologies used were t test, Mann-Whitney U test, and Fisher's exact or χ2 test. In the analysis, 338 RHSCIR participants were included; 65 lived in a rural setting and 273 in an urban setting. Of the original patients residing in a rural area at discharge,10 moved to an urban area by 1 year. Those who moved from a rural to urban area reported a lower SF-36v2™ Mental Component Score (MCS; p = 0.04) and a higher incidence of depression at 1 year (p = 0.04). Urban patients also reported a higher incidence of depression (p = 0.02) and a lower CHIEF-SF total score (p = 0.01) indicating fewer environmental barriers. No significant differences were found in other outcomes. Results suggest that although the patient outcomes are similar, some patients move from rural to urban settings after tSCI. Future efforts should target screening mental health problems early, especially in urban settings. PMID:28462633

Biologic Treatments for Sports Injuries II Think Tank—Current Concepts, Future Research, and Barriers to Advancement, Part 2

PubMed Central

Murray, Iain R.; LaPrade, Robert F.; Musahl, Volker; Geeslin, Andrew G.; Zlotnicki, Jason P.; Mann, Barton J.; Petrigliano, Frank A.

2016-01-01

Rotator cuff tears are common and result in considerable morbidity. Tears within the tendon substance or at its insertion into the humeral head represent a considerable clinical challenge because of the hostile local environment that precludes healing. Tears often progress without intervention, and current surgical treatments are inadequate. Although surgical implants, instrumentation, and techniques have improved, healing rates have not improved, and a high failure rate remains for large and massive rotator cuff tears. The use of biologic adjuvants that contribute to a regenerative microenvironment have great potential for improving healing rates and function after surgery. This article presents a review of current and emerging biologic approaches to augment rotator cuff tendon and muscle regeneration focusing on the scientific rationale, preclinical, and clinical evidence for efficacy, areas for future research, and current barriers to advancement and implementation. PMID:27099865

The Barrier within: Relational Aggression among Women

ERIC Educational Resources Information Center

Brock, Barbara L.

2010-01-01

Relational aggression among women presents an overlooked barrier to women's quest for advancement in the workplace. Although research on women's leadership extols their ability to collaborate and form lasting, supportive relationships, one cannot assume that all women are supportive of other women. Research reveals that relational aggression,…

Exploring parent-reported barriers to supporting their child's health behaviors: a cross-sectional study.

PubMed

Jarvis, Jocelyn W; Harrington, Daniel W; Manson, Heather

2017-05-15

Parents can influence the health behaviors of their children by engaging in supportive behaviors (e.g., playing outside with their child, limiting recreational screen time). How, and the extent to which parents engage in supportive behaviors may be influenced by perceived barriers. The purpose of this study is to explore whether the frequency, and types, of barriers to providing parental support are dependent on the type of child health behavior being supported (i.e., physical activity, recreational screen time reduction, healthy eating, and sleep). Study participants were 1140 Ontario parents with at least one child under the age of 18 who completed a Computer Assisted Telephone Interview (CATI) survey about parental support behaviors. Open-ended responses about perceived barriers to parental support were coded, and aggregated to meta-categories adopted from the social-ecological model (i.e., individual child, individual parent, interpersonal, environmental). Freidman rank sum tests were used to assess differences across child behaviors. Wilcoxon rank sum tests with Bonferroni adjustments were used as a post hoc test for significant Freidman results. There were more barriers reported for supporting physical activity than for any other child behavior (ps < .01, As ≥ .53). Parents reported more parent level and environmental level barriers to supporting child physical activity versus other behaviors (ps < .001, As ≥ .55), child level barriers were more frequently reported for supporting healthy eating and sleep (ps < .001, As ≥ .57), and interpersonal barriers were more frequently reported for supporting recreational screen time reduction (ps < .001, As ≥ .52). Overall, parents reported more child and parent level barriers versus interpersonal and environmental barriers to supporting child health. Parents experience a variety of barriers to supporting their children's health behaviors. Differences in types of barriers across

Adaptation to a steep environmental gradient and an associated barrier to gene exchange in Littorina saxatilis.

PubMed

Grahame, John W; Wilding, Craig S; Butlin, Roger K

2006-02-01

Steep environmental gradients offer important opportunities to study the interaction between natural selection and gene flow. Allele frequency clines are expected to form at loci under selection, but unlinked neutral alleles may pass easily across these clines unless a generalized barrier evolves. Here we consider the distribution of forms of the intertidal gastropod Littorina saxatilis, analyzing shell shape and amplified fragment length polymorphism (AFLP) loci on two rocky shores in Britain. On the basis of previous work, the AFLP loci were divided into differentiated and undifferentiated groups. On both shores, we have shown a sharp cline in allele frequencies between the two morphs for differentiated AFLP loci. This is coincident with a habitat transition on the shore where the two habitats (cliff and boulder field) are immediately contiguous. The allele frequency clines coincide with a cline in shell morphology. In the middle of the cline, linkage disequilibrium for the differentiated loci rises in accordance with expectation. The clines are extremely narrow relative to dispersal, probably as a result of both strong selection and habitat choice. An increase in F(ST) for undifferentiated AFLPs between morphs, relative to within-morph comparisons, is consistent with there being a general barrier to gene flow across the contact zone. These features are consistent either with an episode of allopatric divergence followed by secondary contact or with primary, nonallopatric divergence. Further data will be needed to distinguish between these alternatives.

Impact Resistance of Environmental Barrier Coated SiC/SiC Composites

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.; Choi, Sung R.; Cosgriff, Laura M.; Fox, Dennis S.; Lee, Kang N.

2008-01-01

Impact performance of 2D woven SiC/SiC composites coated with 225 and 525 microns thick environmental barrier coating (EBC) was investigated. The composites were fabricated by melt infiltration and the EBC was deposited by plasma spray. Impact tests were conducted at room temperature and at 1316 C in air using 1.59 mm diameter steel-balls at projectile velocities ranging from 110 to 375 m/s . Both microscopy and non-destructive evaluation (NDE) methods were used to determine the extent of damage in the substrate and coating with increasing projectile velocity. The impacted specimens were tensile tested at room temperature to determine their residual mechanical properties. At projectile velocities less than 125 m/s , no detectable internal damage was noticed in the MI SiC/SiC composites coated with 525 microns EBC. With increase in projectile velocity beyond this value, spallation of EBC layers, delamination of fiber plies, and fiber fracture were detected. At a fixed projectile velocity, the composites coated with 525 microns EBC showed less damage than those coated with 225 microns EBC. Both types of coated composites retained a large fraction of the baseline properties of the as-fabricated composites and exhibited non-brittle failure after impact testing. Furnace exposure of impacted specimens in a moisture environment at 1316 C for 500 h indicated that the through-the-thickness cracks in the coating and delamination cracks in the substrate generated after impact testing acted as conduits for internal oxidation.

Advanced Space Flight and Environmental Concerns

NASA Technical Reports Server (NTRS)

Whitaker, A.

2001-01-01

The aerospace industry has conquered numerous environmental challenges during the last decade. The aerospace industry of today has evolved due in part to the environmental challenges, becoming stronger, more robust, learning to push the limits of technology, materials and manufacturing, and performing cutting edge engineering.

Advance directives in patients with advanced cancer receiving active treatment: attitudes, prevalence, and barriers.

PubMed

McDonald, Julie C; du Manoir, Jeanne M; Kevork, Nanor; Le, Lisa W; Zimmermann, Camilla

2017-02-01

The purposes of the study were to assess awareness and prevalence of advance directives (ADs) among patients with advanced cancer undergoing active outpatient care and to determine factors associated with AD completion before and after the diagnosis of cancer. Patients with advanced solid tumor malignancy receiving treatment at the Chemotherapy Day Unit were approached for recruitment. They completed an onsite questionnaire about completion and timing of ADs, demographic information, and perceived health; a review of their medical records was conducted to document their cancer care and co-morbidities. Multinomial logistic regression analysis identified factors associated with the timing of AD completion (pre-cancer, post-cancer, or not at all). Two hundred patients were enrolled, with 193 surveys available for analysis. ADs were completed in 55 % (106/193) of patients, including a living will in 33 % (63/193), a power of attorney in 49 % (95/193), and a do-not-resuscitate (DNR) designation in 18 % (35/193). Most patients (53 %) had completed an AD before being diagnosed with cancer. Higher income (p = 0.02) and age (p = 0.004) were associated with AD completion pre-cancer diagnosis; discussion of end-of-life care (p = 0.02) and palliative care referral (p < 0.0001) were associated with AD completion post-cancer diagnosis. This study demonstrates that different factors may influence the completion of ADs before and after a diagnosis of cancer and highlights the potential for early palliative care to impact the completion of ADs in patients with advanced cancer who are undergoing active cancer treatment.

Towards environmental management of water turbidity within open coastal waters of the Great Barrier Reef.

PubMed

Macdonald, Rachael K; Ridd, Peter V; Whinney, James C; Larcombe, Piers; Neil, David T

2013-09-15

Water turbidity and suspended sediment concentration (SSC) are commonly used as part of marine monitoring and water quality plans. Current management plans utilise threshold SSC values derived from mean-annual turbidity concentrations. Little published work documents typical ranges of turbidity for reefs within open coastal waters. Here, time-series turbidity measurements from 61 sites in the Great Barrier Reef (GBR) and Moreton Bay, Australia, are presented as turbidity exceedance curves and derivatives. This contributes to the understanding of turbidity and SSC in the context of environmental management in open-coastal reef environments. Exceedance results indicate strong spatial and temporal variability in water turbidity across inter/intraregional scales. The highest turbidity across 61 sites, at 50% exceedance (T50) is 15.3 NTU and at 90% exceedance (T90) 4.1 NTU. Mean/median turbidity comparisons show strong differences between the two, consistent with a strongly skewed turbidity regime. Results may contribute towards promoting refinement of water quality management protocols. Copyright © 2013 Elsevier Ltd. All rights reserved.

Learning from social media: utilizing advanced data extraction techniques to understand barriers to breast cancer treatment.

PubMed

Freedman, Rachel A; Viswanath, Kasisomayajula; Vaz-Luis, Ines; Keating, Nancy L

2016-07-01

Past examinations of breast cancer treatment barriers have typically included registry, claims-based, and smaller survey studies. We examined treatment barriers using a novel, comprehensive, social media analysis of online, candid discussions about breast cancer. Using an innovative toolset to search postings on social networks, message boards, patient communities, and topical sites, we performed a large-scale qualitative analysis. We examined the sentiments and barriers expressed about breast cancer treatments by Internet users during 1 year (2/1/14-1/31/15). We categorized posts based on thematic patterns and examined trends in discussions by race/ethnicity (white/black/Hispanic) when this information was available. We identified 1,024,041 unique posts related to breast cancer treatment. Overall, 57 % of posts expressed negative sentiments. Using machine learning software, we assigned treatment barriers for 387,238 posts (38 %). Barriers included emotional (23 % of posts), preferences and spiritual/religious beliefs (21 %), physical (18 %), resource (15 %), healthcare perceptions (9 %), treatment processes/duration (7 %), and relationships (7 %). Black and Hispanic (vs. white) users more frequently reported barriers related to healthcare perceptions, beliefs, and pre-diagnosis/diagnosis organizational challenges and fewer emotional barriers. Using a novel analysis of diverse social media users, we observed numerous breast cancer treatment barriers that differed by race/ethnicity. Social media is a powerful tool, allowing use of real-world data for qualitative research, capitalizing on the rich discussions occurring spontaneously online. Future research should focus on how to further employ and learn from this type of social intelligence research across all medical disciplines.

Barrier island arcs along abandoned Mississippi River deltas

USGS Publications Warehouse

Penland, S.; Suter, J.R.; Boyd, Ron

1985-01-01

Generation of transgressive barrier island arcs along the Mississippi River delta plain and preservation of barrier shoreline facies in their retreat paths on the inner shelf is controlled by: (1) shoreface translation; (2) age of the transgression; and (3) the thickness of the barrier island arc sediment package. Barrier island arcs experience an average relative sea level rise of 0.50-1.00 cm yr-1 and shoreface retreat rates range from 5-15 m yr-1. Young barrier island arc sediment packages (Isles Dernieres) are thin and have experienced limited landward retreat of the shoreface. Older barrier island arcs (Chandeleur Islands) are thicker and have experienced significant landward movement of the shoreface because of the greater time available for retreat. If the transgressed barrier shoreline sediment package lies above the advancing ravinement surface, the entire sequence is truncated. A thin reworked sand sheet marks the shoreface retreat path. The base of the transgressive sediment package can lie below the ravinement surface in older barrier shorelines. In this setting, the superstructure of the barrier shoreline is truncated, leaving the basal portion of the transgressive sequence preserved on the inner shelf. A variety of transgressive stratigraphic sequences from sand sheets to truncated barrier islands to sand-filled tidal inlet scars have been identified by high resolution seismic profiling across the shoreface retreat paths of Mississippi delta barrier island arcs. One of these examples, the Isles Dernieres, represents a recently detached barrier island arc in the early stages of transgression. An older example, the Chandeleur Islands, represents a barrier island arc experiencing long-term shoreface retreat. This paper describes the stratigraphic character and preserved transgressive facies for the Isles Dernieres and Chandeleur Islands. ?? 1985.

Delamination Mechanisms of Thermal and Environmental Barrier Coatings on SiC/SiC Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Choi, Sung R.; Lee, Kang N.; Miller, Robert A.

2003-01-01

Advanced ceramic thermal harrier coatings will play an increasingly important role In future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability issue remains a major concern with the ever-increasing temperature requirements. In this paper, thermal cyclic response and delamination failure modes of a ZrO2-8wt%Y2O3 and mullite/BSAS thermaVenvironmenta1 barrier coating system on SiC/SiC ceramic matrix composites were investigated using a laser high-heat-flux technique. The coating degradation and delamination processes were monitored in real time by measuring coating apparent conductivity changes during the cyclic tests under realistic engine temperature and stress gradients, utilizing the fact that delamination cracking causes an apparent decrease in the measured thermal conductivity. The ceramic coating crack initiation and propagation driving forces under the cyclic thermal loads, in conjunction with the mechanical testing results, will be discussed.

Barriers to healthy-lifestyle participation in stroke: consumer participation in secondary prevention design.

PubMed

Lennon, Olive C; Doody, Catherine; Ni Choisdealbh, Cliodhna; Blake, Catherine

2013-12-01

The aim of the study was to explore community-dwelling stroke patients' perceived barriers to healthy-lifestyle participation for secondary disease prevention, as well as their preferred means for risk-reduction information dissemination and motivators to participation in healthy-lifestyle interventions. Four focus groups (5-6 stroke survivors per group) were defined from community support groups. Key questions addressed barriers to healthy-lifestyle adoption, preferred methods for receiving information and factors that would engage participants in a risk-reduction programme. Groups were audiotaped, transcribed verbatim and analysed for thematic content using a framework approach. Twenty-two participants, 12 men, 10 women, mean age 71.4 (53-87) years, were included in the study. Three overarching themes emerged as barriers to healthy-lifestyle participation: physical, mental and environmental. Exercise participation difficulties spread across all three themes; healthy eating and smoking cessation concentrated in environmental and mental dimensions. Talks (discussions) were noted as participants' preferred method of information provision. Risk-reduction programmes considered attractive were stroke specific, convenient and delivered by healthcare professionals and involved both social and exercise components. Many stroke patients appear unable to adopt healthy-lifestyle changes through advice alone because of physical, mental and environmental barriers. Risk-reduction programmes including interactive education should be specifically tailored to address barriers currently experienced and extend beyond the stroke survivor to others in their environment who influence lifestyle choices.

Recent Advances in Gas Barrier Thin Films via Layer-by-Layer Assembly of Polymers and Platelets.

PubMed

Priolo, Morgan A; Holder, Kevin M; Guin, Tyler; Grunlan, Jaime C

2015-05-01

Layer-by-layer (LbL) assembly has emerged as the leading non-vacuum technology for the fabrication of transparent, super gas barrier films. The super gas barrier performance of LbL deposited films has been demonstrated in numerous studies, with a variety of polyelectrolytes, to rival that of metal and metal oxide-based barrier films. This Feature Article is a mini-review of LbL-based multilayer thin films with a 'nanobrick wall' microstructure comprising polymeric mortar and nano-platelet bricks that impart high gas barrier to otherwise permeable polymer substrates. These transparent, water-based thin films exhibit oxygen transmission rates below 5 × 10(-3) cm(3) m(-2) day(-1) atm(-1) and lower permeability than any other barrier material reported. In an effort to put this technology in the proper context, incumbent technologies such as metallized plastics, metal oxides, and flake-filled polymers are briefly reviewed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A tunable acoustic barrier based on periodic arrays of subwavelength slits

NASA Astrophysics Data System (ADS)

Rubio, Constanza; Uris, Antonio; Candelas, Pilar; Belmar, Francisco; Gomez-Lozano, Vicente

2015-05-01

The most usual method to reduce undesirable enviromental noise levels during its transmission is the use of acoustic barriers. A novel type of acoustic barrier based on sound transmission through subwavelength slits is presented. This system consists of two rows of periodic repetition of vertical rigid pickets separated by a slit of subwavelength width and with a misalignment between them. Here, both the experimental and the numerical analyses are presented. The acoustic barrier proposed can be easily built and is frequency tunable. The results demonstrated that the proposed barrier can be tuned to mitigate a band noise without excesive barrier thickness. The use of this system as an environmental acoustic barrier has certain advantages with regard to the ones currently used both from the constructive and the acoustical point of view.

Environmental barrier coating (EBC) durability modeling using a progressive failure analysis approach

NASA Astrophysics Data System (ADS)

Abdul-Aziz, Ali; Abumeri, Galib; Troha, William; Bhatt, Ramakrishna T.; Grady, Joseph E.; Zhu, D.

2012-04-01

Ceramic matrix composites (CMCs) are getting the attention of most engine manufacturers and aerospace firms for turbine engine and other related applications. This is because of their potential weight advantage and performance benefits. As a protecting guard for these materials, a highly specialized form of environmental barrier coating (EBC) is being developed and explored for high temperature applications that are greater than 1100 °C1,2. The EBCs are typically a multilayer of coatings and are on the order of hundreds of microns thick. CMCs are generally porous materials and this feature is somewhat beneficial since it allows some desirable infiltration of the EBC. Their degradation usually includes coating interface oxidation as opposed to moisture induced matrix degradation which is generally seen at a higher temperature. A variety of factors such as residual stresses, coating process related flaws, and casting conditions may influence the strength of degradation. The cause of such defects which cause cracking and other damage is that not much energy is absorbed during fracture of these materials. Therefore, an understanding of the issues that control crack deflection and propagation along interfaces is needed to maximize the energy dissipation capabilities of layered ceramics. Thus, evaluating components and subcomponents made out of CMCs under gas turbine engine conditions is suggested to demonstrate that these material will perform as expected and required under these aggressive environmental circumstances. Progressive failure analysis (PFA) is applied to assess the damage growth of the coating under combined thermal and mechanical loading conditions. The PFA evaluation is carried out using a full-scale finite element model to account for the average material failure at the microscopic or macroscopic levels. The PFA life prediction evaluation identified the root cause for damage initiation and propagation. It indicated that delamination type damage

Supplemental final environmental impact statement for advanced solid rocket motor testing at Stennis Space Center

NASA Technical Reports Server (NTRS)

1990-01-01

Since the Final Environmental Impact Statement (FEIS) and Record of Decision on the FEIS describing the potential impacts to human health and the environment associated with the program, three factors have caused NASA to initiate additional studies regarding these issues. These factors are: (1) The U.S. Army Corps of Engineers and the Environmental Protection Agency (EPA) agreed to use the same comprehensive procedures to identify and delineate wetlands; (2) EPA has given NASA further guidance on how best to simulate the exhaust plume from the Advanced Solid Rocket Motor (ASRM) testing through computer modeling, enabling more realistic analysis of emission impacts; and (3) public concerns have been raised concerning short and long term impacts on human health and the environment from ASRM testing.

Recent advances in environmental data mining

NASA Astrophysics Data System (ADS)

Leuenberger, Michael; Kanevski, Mikhail

2016-04-01

Due to the large amount and complexity of data available nowadays in geo- and environmental sciences, we face the need to develop and incorporate more robust and efficient methods for their analysis, modelling and visualization. An important part of these developments deals with an elaboration and application of a contemporary and coherent methodology following the process from data collection to the justification and communication of the results. Recent fundamental progress in machine learning (ML) can considerably contribute to the development of the emerging field - environmental data science. The present research highlights and investigates the different issues that can occur when dealing with environmental data mining using cutting-edge machine learning algorithms. In particular, the main attention is paid to the description of the self-consistent methodology and two efficient algorithms - Random Forest (RF, Breiman, 2001) and Extreme Learning Machines (ELM, Huang et al., 2006), which recently gained a great popularity. Despite the fact that they are based on two different concepts, i.e. decision trees vs artificial neural networks, they both propose promising results for complex, high dimensional and non-linear data modelling. In addition, the study discusses several important issues of data driven modelling, including feature selection and uncertainties. The approach considered is accompanied by simulated and real data case studies from renewable resources assessment and natural hazards tasks. In conclusion, the current challenges and future developments in statistical environmental data learning are discussed. References - Breiman, L., 2001. Random Forests. Machine Learning 45 (1), 5-32. - Huang, G.-B., Zhu, Q.-Y., Siew, C.-K., 2006. Extreme learning machine: theory and applications. Neurocomputing 70 (1-3), 489-501. - Kanevski, M., Pozdnoukhov, A., Timonin, V., 2009. Machine Learning for Spatial Environmental Data. EPFL Press; Lausanne, Switzerland, p.392

Resistance of Nanostructured Environmental Barrier Coatings to the Movement of Molten Salts

NASA Astrophysics Data System (ADS)

Rao, S.; Frederick, L.; McDonald, A.

2012-09-01

Corrosion of components in a recovery boiler is a major problem faced by the pulp and paper industry. The superheater tubes become severely corroded due to the presence of sulfidic gases in the boiler and molten salts which are deposited on the surface of the tubes. As a result, the boiler must be decommissioned for expensive maintenance and repairs. Yttria-stabilized zirconia (YSZ) coatings have been shown to provide corrosion resistance when applied on gas turbines operating at high temperatures. Air plasma-sprayed YSZ environmental barrier coatings on Type 309 stainless steel were exposed to three different corrosive environments: Test A—600 °C, salt vapors, flue gases, 168 h; Test B—600 °C, molten salt, air, 168 h; and Test C—600 °C, molten salt, flue gases, 168 h. Two different types of YSZ coatings—conventional YSZ and nanostructured YSZ—were tested to study their resistance to corrosion and molten salt penetration. The performances of both types of coatings were evaluated, and a comparative study was conducted. It was found that the nanostructured YSZ samples protected the stainless steel substrate better than their conventional counterparts. This superior performance was attributed to the presence of semi-molten nano-agglomerates present in the coating microstructure, which acted as collection points for the penetrating molten salts.

Thermal barriers constrain microbial elevational range size via climate variability.

PubMed

Wang, Jianjun; Soininen, Janne

2017-08-01

Range size is invariably limited and understanding range size variation is an important objective in ecology. However, microbial range size across geographical gradients remains understudied, especially on mountainsides. Here, the patterns of range size of stream microbes (i.e., bacteria and diatoms) and macroorganisms (i.e., macroinvertebrates) along elevational gradients in Asia and Europe were examined. In bacteria, elevational range size showed non-significant phylogenetic signals. In all taxa, there was a positive relationship between niche breadth and species elevational range size, driven by local environmental and climatic variables. No taxa followed the elevational Rapoport's rule. Climate variability explained the most variation in microbial mean elevational range size, whereas local environmental variables were more important for macroinvertebrates. Seasonal and annual climate variation showed negative effects, while daily climate variation had positive effects on community mean elevational range size for all taxa. The negative correlation between range size and species richness suggests that understanding the drivers of range is key for revealing the processes underlying diversity. The results advance the understanding of microbial species thermal barriers by revealing the importance of seasonal and diurnal climate variation, and highlight that aquatic and terrestrial biota may differ in their response to short- and long-term climate variability. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Man's Impact on the Environment: The Barrier Beach as an Ecosystem. Update.

ERIC Educational Resources Information Center

Brevard County School Board, Cocoa, FL.

This environmental education program emphasizes the cause and effect of change in a barrier beach ecosystem with special attention given to man and his role in environmental change. Concepts are employed from the natural and social sciences to investigate environmental problems. The units are designed around these questions: (1) What is an…

Coated silicon comprising material for protection against environmental corrosion

NASA Technical Reports Server (NTRS)

Hazel, Brian Thomas (Inventor)

2009-01-01

In accordance with an embodiment of the invention, an article is disclosed. The article comprises a gas turbine engine component substrate comprising a silicon material; and an environmental barrier coating overlying the substrate, wherein the environmental barrier coating comprises cerium oxide, and the cerium oxide reduces formation of silicate glass on the substrate upon exposure to corrodant sulfates.

Advancing the Careers of Women with Children

ERIC Educational Resources Information Center

Metz, Isabel

2005-01-01

Purpose: This study aims to assess whether differences exist in the barriers reported by, and in the person- and situation-centred factors related to the managerial advancement of, women with and without children. The study also seeks to examine whether having children influences womens advancement, by affecting person-situation factors such as…

Cost/benefit studies of advanced materials technologies for future aircraft turbine engines: Materials for advanced turbine engines

NASA Technical Reports Server (NTRS)

Stearns, M.; Wilbers, L.

1982-01-01

Cost benefit studies were conducted on six advanced materials and processes technologies applicable to commercial engines planned for production in the 1985 to 1990 time frame. These technologies consisted of thermal barrier coatings for combustor and high pressure turbine airfoils, directionally solidified eutectic high pressure turbine blades, (both cast and fabricated), and mixers, tail cones, and piping made of titanium-aluminum alloys. A fabricated titanium fan blisk, an advanced turbine disk alloy with improved low cycle fatigue life, and a long-life high pressure turbine blade abrasive tip and ceramic shroud system were also analyzed. Technologies showing considerable promise as to benefits, low development costs, and high probability of success were thermal barrier coating, directionally solidified eutectic turbine blades, and abrasive-tip blades/ceramic-shroud turbine systems.

Rewards and advancements for clinical pharmacists.

PubMed

Goodwin, S Diane; Kane-Gill, Sandra L; Ng, Tien M H; Melroy, Joel T; Hess, Mary M; Tallian, Kimberly; Trujillo, Toby C; Vermeulen, Lee C

2010-01-01

The American College of Clinical Pharmacy charged the Clinical Practice Affairs Committee to review and update the College's 1995 White Paper, "Rewards and Advancements for Clinical Pharmacy Practitioners." Because of the limited data on the present state of rewards and advancements for clinical pharmacists, an online survey of "front-line" clinical pharmacists and pharmacy managers was conducted (1126 total respondents, 14% response rate). The resulting White Paper discusses motivators and existing systems of rewards and advancements for clinical pharmacists, as well as perceived barriers to implementation of these systems. Clinical pharmacists reported work-life balance, a challenging position, and opportunities for professional advancement as the most important factors for career success. At the time of the survey, financial rewards appeared not to be a major motivator for clinical pharmacists. Managers underestimated the importance that clinical pharmacists place on work-life balance and favorable work schedules. Although almost two thirds of the clinical pharmacists surveyed had not developed a professional development plan, 84% indicated an interest in career planning. Both clinical pharmacists and managers rated the lack of a clear reward and advancement structure as the most important barrier to effective systems of rewards and advancements. Pharmacy managers and administrators are encouraged to develop effective systems of rewards and advancements for clinical pharmacists that positively impact patient care and the institution's mission; these systems will benefit the clinical pharmacist, the health care institution, and the patient.

Understanding Motivators and Barriers to Physical Activity

ERIC Educational Resources Information Center

Patay, Mary E.; Patton, Kevin; Parker, Melissa; Fahey, Kathleen; Sinclair, Christina

2015-01-01

The purpose of this study was to understand the factors that influence physical activity among year-round residents in an isolated summer resort community. Specifically, we explored the personal, environmental, social, and culture-specific perceived motivators and barriers to physical activity. Participants were formally interviewed about their…

Ocean barrier layers' effect on tropical cyclone intensification.

PubMed

Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

Barrier or Benefit? Emotion in Life-Career Design

ERIC Educational Resources Information Center

Hartung, Paul J.

2011-01-01

Emotion permeates human life, yet receives little attention in career theory and intervention. Long seen as a barrier to avoid, recent conceptual and empirical work indicate that emotion benefits human behavior and development. Advances in the interdisciplinary science of emotion support examining the construct across differential, developmental,…

MICROBIAL CHARACTERIZATION OF MANURE BASED PERMEABLE REACTIVE BARRIER

EPA Science Inventory

The implementation of permeable reactive barriers (PRB) provides a viable option for the remediation of contaminants of environmental significance such as dissolved metals (i.e., chromium), chlorinated solvents, and nitrate/ammonia. The designs of PRBs are usually based on the a...

Causality, apparent ``superluminality,'' and reshaping in barrier penetration

NASA Astrophysics Data System (ADS)

Sokolovski, D.

2010-04-01

We consider tunneling of a nonrelativistic particle across a potential barrier. It is shown that the barrier acts as an effective beam splitter which builds up the transmitted pulse from the copies of the initial envelope shifted in the coordinate space backward relative to the free propagation. Although along each pathway causality is explicitly obeyed, in special cases reshaping can result an overall reduction of the initial envelope, accompanied by an arbitrary coordinate shift. In the case of a high barrier the delay amplitude distribution (DAD) mimics a Dirac δ function, the transmission amplitude is superoscillatory for finite momenta and tunneling leads to an accurate advancement of the (reduced) initial envelope by the barrier width. In the case of a wide barrier, initial envelope is accurately translated into the complex coordinate plane. The complex shift, given by the first moment of the DAD, accounts for both the displacement of the maximum of the transmitted probability density and the increase in its velocity. It is argued that analyzing apparent “superluminality” in terms of spacial displacements helps avoid contradiction associated with time parameters such as the phase time.

Ceramic thermal barrier coatings for commercial gas turbine engines

NASA Technical Reports Server (NTRS)

Meier, Susan Manning; Gupta, Dinesh K.; Sheffler, Keith D.

1991-01-01

The paper provides an overview of the short history, current status, and future prospects of ceramic thermal barrier coatings for gas turbine engines. Particular attention is given to plasma-sprayed and electron beam-physical vapor deposited yttria-stabilized (7 wt pct Y2O3) zirconia systems. Recent advances include improvements in the spallation life of thermal barrier coatings, improved bond coat composition and spraying techniques, and improved component design. The discussion also covers field experience, life prediction modeling, and future directions in ceramic coatings in relation to gas turbine engine design.

Toward a New U.S. Chemicals Policy: Rebuilding the Foundation to Advance New Science, Green Chemistry, and Environmental Health

PubMed Central

Wilson, Michael P.; Schwarzman, Megan R.

2009-01-01

Objective We describe fundamental weaknesses in U.S. chemicals policy, present principles of chemicals policy reform, and articulate interdisciplinary research questions that should be addressed. With global chemical production projected to double over the next 24 years, federal policies that shape the priorities of the U.S. chemical enterprise will be a cornerstone of sustainability. To date, these policies have largely failed to adequately protect public health or the environment or motivate investment in or scientific exploration of cleaner chemical technologies, known collectively as green chemistry. On this trajectory, the United States will face growing health, environmental, and economic problems related to chemical exposures and pollution. Conclusions Existing policies have produced a U.S. chemicals market in which the safety of chemicals for human health and the environment is undervalued relative to chemical function, price, and performance. This market barrier to green chemistry is primarily a consequence of weaknesses in the Toxic Substances Control Act. These weaknesses have produced a chemical data gap, because producers are not required to investigate and disclose sufficient information on chemicals’ hazard traits to government, businesses that use chemicals, or the public; a safety gap, because government lacks the legal tools it needs to efficiently identify, prioritize, and take action to mitigate the potential health and environmental effects of hazardous chemicals; and a technology gap, because industry and government have invested only marginally in green chemistry research, development, and education. Policy reforms that close the three gaps—creating transparency and accountability in the market—are crucial for improving public and environmental health and reducing the barriers to green chemistry. The European Union’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation has opened an opportunity for

Toward a new U.S. chemicals policy: rebuilding the foundation to advance new science, green chemistry, and environmental health.

PubMed

Wilson, Michael P; Schwarzman, Megan R

2009-08-01

We describe fundamental weaknesses in U.S. chemicals policy, present principles of chemicals policy reform, and articulate interdisciplinary research questions that should be addressed. With global chemical production projected to double over the next 24 years, federal policies that shape the priorities of the U.S. chemical enterprise will be a cornerstone of sustainability. To date, these policies have largely failed to adequately protect public health or the environment or motivate investment in or scientific exploration of cleaner chemical technologies, known collectively as green chemistry. On this trajectory, the United States will face growing health, environmental, and economic problems related to chemical exposures and pollution. Existing policies have produced a U.S. chemicals market in which the safety of chemicals for human health and the environment is undervalued relative to chemical function, price, and performance. This market barrier to green chemistry is primarily a consequence of weaknesses in the Toxic Substances Control Act. These weaknesses have produced a chemical data gap, because producers are not required to investigate and disclose sufficient information on chemicals' hazard traits to government, businesses that use chemicals, or the public; a safety gap, because government lacks the legal tools it needs to efficiently identify, prioritize, and take action to mitigate the potential health and environmental effects of hazardous chemicals; and a technology gap, because industry and government have invested only marginally in green chemistry research, development, and education. Policy reforms that close the three gaps-creating transparency and accountability in the market-are crucial for improving public and environmental health and reducing the barriers to green chemistry. The European Union's REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation has opened an opportunity for the United States to take this

Barriers to wheelchair use in the winter.

PubMed

Ripat, Jacquie D; Brown, Cara L; Ethans, Karen D

2015-06-01

To test the hypothesis that challenges to community participation posed by winter weather are greater for individuals who use scooters, manual and power wheelchairs (wheeled mobility devices [WMDs]) than for the general ambulatory population, and to determine what WMD users identify as the most salient environmental barriers to community participation during the winter. Cross-sectional survey organized around 5 environmental domains: technological, natural, physical, social/attitudinal, and policy. Urban community in Canada. Convenience sample of WMD users or their proxy (N=99). Not applicable. Not applicable. Forty-two percent identified reduced outing frequency in winter months, associated with increased age (χ(3)=6.4, P=.04), lack of access to family/friends for transportation (χ(2)=8.1, P=.04), and primary type of WMD used in the winter (scooter χ(2)=8.8, P=.003). Most reported tires/casters becoming stuck in the snow (95%) or slipping on the ice (91%), difficulty ascending inclines/ramps (92%), and cold hands while using controls or pushing rims (85%); fewer identified frozen wheelchair/scooter batteries, seat cushions/backrests, or electronics. Sidewalks/roads were reported to be problematic by 99%. Eighty percent reported needing additional help in the winter. Limited community access in winter led to a sense of loneliness/isolation, and fear/anxiety related to safety. Respondents identified policies that limited participation during winter. People who use WMDs decrease their community participation in cold weather because of multiple environmental barriers. Clinicians, researchers, and policymakers can take a multidimensional approach to mitigate these barriers in order to enhance community participation by WMD users in winter. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

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.

Some Nutritional, Technological and Environmental Advances in the Use of Enzymes in Meat Products

PubMed Central

Marques, Anne y Castro; Maróstica, Mário Roberto; Pastore, Gláucia Maria

2010-01-01

The growing consumer demand for healthier products has stimulated the development of nutritionally enhanced meat products. However, this can result in undesirable sensory consequences to the product, such as texture alterations in low-salt and low-phosphate meat foods. Additionally, in the meat industry, economical aspects have stimulated researchers to use all the animal parts to maximize yields of marketable products. This paper aimed to show some advances in the use of enzymes in meat processing, particularly the application of the proteolytic enzymes transglutaminase and phytases, associated with nutritional, technological, and environmental improvements. PMID:21048865

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

NASA Technical Reports Server (NTRS)

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

2010-01-01

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

Perceptions of Approved Clinical Instructors: Barriers in the Implementation of Evidence-Based Practice

PubMed Central

Hankemeier, Dorice A.; Van Lunen, Bonnie L.

2013-01-01

Context: As evidence-based practice (EBP) becomes prevalent in athletic training education, the barriers that Approved Clinical Instructors (ACIs) experience in implementing it with students need to be understood. Objective: To investigate barriers ACIs face when implementing EBP concepts in clinical practice and in teaching EBP to professional athletic training students and to investigate the educational emphases to improve the barriers. Design: Qualitative study. Setting: Telephone interviews. Patients or Other Participants: Sixteen ACIs (11 men, 5 women; experience as an athletic trainer = 10 ± 4.7 years, experience as an ACI = 6.81 ± 3.9 years) were interviewed. Data Collection and Analysis: We interviewed each participant by telephone. Interview data were analyzed and coded for common themes and subthemes regarding barriers and educational emphases. Themes were triangulated through multiple-analyst triangulation and interpretive verification. Results: Barriers to EBP incorporation and educational emphasis placed on EBP were the main themes reported. Resources, personnel, and student characteristics were subthemes identified as barriers. Resource barriers included time, equipment, access to current literature, and knowledge. Coworkers, clinicians, and coaches who were unwilling to accept evidence regarding advancements in treatment were identified as personnel barriers. Programmatic improvement and communication improvement were subthemes of the educational emphasis placed on EBP theme. The ACIs reported the need for better integration between the clinical setting and the classroom and expressed the need for EBP to be integrated throughout the athletic training education program. Conclusions: Integration of the classroom and clinical experience is important in advancing ACIs' use of EBP with their students. Collaborative efforts within the clinical and academic program could help address the barriers ACIs face when implementing EBP. This collaboration could

FY2016 Advanced Combustion Engine Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None, None

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

FY2014 Advanced Combustion Engine Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2015-03-01

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

FY2015 Advanced Combustion Engine Annual Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Gurpreet; Gravel, Roland M.; Howden, Kenneth C.

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

The myth of natural barriers. Is transgene introgression by genetically modified crops an environmental risk?

PubMed

Guarnieri, Vincenzo; Benessia, Alice; Camino, Elena; Barbiero, Giuseppe

2008-01-01

Genetically modified (GM) crops under open field conditions are a complex and controversial issue. Ecologists are discussing about the possibility that a transgene belonging to GM plants could spread to native populations through a process known as introgression the stable incorporation of a gene in the host genome able to generate a differentiated population. The ecological consequences of a transgene introgression in plants or bacteria are not yet well understood, but could be significant. In this critical review we consider vertical and horizontal introgression. We analyse the biochemical and genetic constraints, and environmental factors that limit the possibility of transgene spread; meanwhile we show cases in which the natural barriers are overcome. Then we discuss the overall management of GM crops, noting the shortcomings and approximations of risk assessment based on linear thinking typical of the biomolecular approach. Finally we suggest to explicitly weight facts together with values and we encourage the undertaking of an ecological perspective, encompassing the complexity of (non-linear) relations between organisms and the environment.

Political advocacy and practice barriers: a survey of Florida APRNs.

PubMed

Kung, Ying Mai; Rudner Lugo, Nancy

2015-03-01

This study examined factors aligned with advocacy among advanced practice registered nurses (APRNs) by examining the relationships among demographics, years of RN and APRN experience, education levels, affiliations with professional organizations, perceptions of barriers to practice, political activism, and willingness to speak to the media. This was a secondary analysis of online survey data (N = 884) from APRNs in Florida. All APRNs with an e-mail address with the state nursing board or a Florida Coalition of Advanced Practice Nurses' membership organization received an e-mail requesting their participation to the survey. Having a high educational level and involvement in a professional organization are each individually statistically associated with perceiving practice barriers, engaging in political activism, and willingness to speak with media. Emerging nurse leaders need an understanding of policy issues, an appreciation of the potential of the profession, and enhanced advocacy skills. To address the nation's health needs, APRNs need to recognize practice barriers, develop advocacy skills, and take action for policy changes to enhance the legal authority to practice to full extent of APRNs' education and training. ©2014 American Association of Nurse Practitioners.

Advancing the quality of environmental microplastic research.

PubMed

Connors, Kristin A; Dyer, Scott D; Belanger, Scott E

2017-07-01

Investigations into the environmental fate and effects of microplastics have been gaining momentum. Small, insoluble polymeric particles are implicated by scientists in a wide variety of studies that are used to suggest a potential for widespread impacts in freshwater and marine pelagic and sediment environments. An exponential growth in scientific publications and an increase in regulatory attention have occurred. However, despite these efforts, the environmental hazard of these particles is still unknown. To evaluate the hazard of microplastics within a risk assessment context, we need a way to evaluate the quality of experimental studies. We performed a thorough review of the quality and focus of environmental microplastic research, to understand the methodologies employed and how this may assist or distract from the ability of environmental risk assessors to evaluate microplastics. We provide guidance to improve the reliability and relevance of ecotoxicological studies for regulatory and broader environmental assessments. Nine areas of needed improvement are identified and discussed. Important data gaps and experimental limitations are highlighted. Environ Toxicol Chem 2017;36:1697-1703. © 2017 SETAC. © 2017 SETAC.

Low humidity environmental challenge causes barrier disruption and cornification of the mouse corneal epithelium via a c-jun N-terminal kinase 2 (JNK2) pathway.

PubMed

Pelegrino, F S A; Pflugfelder, S C; De Paiva, C S

2012-01-01

Patients with tear dysfunction often experience increased irritation symptoms when subjected to drafty and/or low humidity environmental conditions. The purpose of this study was to investigate the effects of low humidity stress (LHS) on corneal barrier function and expression of cornified envelope (CE) precursor proteins in the epithelium of C57BL/6 and c-jun N-terminal kinase 2 (JNK2) knockout (KO) mice. LHS was induced in both strains by exposure to an air draft for 15 (LHS15D) or 30 days (LHS30D) at a relative humidity <30%RH. Nonstressed (NS) mice were used as controls. Oregon-green-dextran uptake was used to measure corneal barrier function. Levels of small proline-rich protein (SPRR)-2, involucrin, occludin, and MMP-9 were evaluated by immunofluorescent staining in cornea sections. Wholemount corneas immunostained for occludin were used to measure mean apical cell area. Gelatinase activity was evaluated by in situ zymography. Expression of MMP, CE and inflammatory cytokine genes was evaluated by qPCR. C57BL/6 mice exposed to LHS15D showed corneal barrier dysfunction, decreased apical corneal epithelial cell area, higher MMP-9 expression and gelatinase activity and increased involucrin and SPRR-2 immunoreactivity in the corneal epithelium compared to NS mice. JNK2KO mice were resistant to LHS-induced corneal barrier disruption. MMP-3,-9,-13, IL-1α, IL-1β, involucrin and SPRR-2a RNA transcripts were significantly increased in C57BL/6 mice at LHS15D, while no change was noted in JNK2KO mice. LHS is capable of altering corneal barrier function, promoting pathologic alteration of the TJ complex and stimulating production of CE proteins by the corneal epithelium. Activation of the JNK2 signaling pathway contributes to corneal epithelial barrier disruption in LHS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Interactive Higher Education Instruction to Advance STEM Instruction in the Environmental Sciences - the Brownfield Action Model

NASA Astrophysics Data System (ADS)

Liddicoat, J. C.; Bower, P.

2015-12-01

The U.S. Environmental Protection Agency estimates that presently there are over half a million brownfields in the United States, but this number only includes sites for which an Environmental Site Assessment has been conducted. The actual number of brownfields is certainly in the millions and constitutes one of the major environmental issues confronting all communities today. Taught in part or entirely online for more than 15 years in environmental science, engineering, and hydrology courses at over a dozen colleges, universities, and high schools in the United States, Brownfield Action (BA) is an interactive, web-based simulation that combines scientific expertise, constructivist education philosophy, and multimedia to advance the teaching of environmental science (Bower et al., 2011, 2014; Liddicoat and Bower, 2015). In the online simulation and classroom, students form geotechnical consulting companies with a peer chosen at random to solve a problem in environmental forensics. The BA model contains interdisciplinary scientific and social information that are integrated within a digital learning environment that encourages students to construct their knowledge as they learn by doing. As such, the approach improves the depth and coherence of students understanding of the course material. Like real-world environmental consultants and professionals, students are required to develop and apply expertise from a wide range of fields, including environmental science and engineering as well as journalism, medicine, public health, law, civics, economics, and business management. The overall objective is for students to gain an unprecedented appreciation of the complexity, ambiguity, and risk involved in any environmental issue, and to acquire STEM knowledge that can be used constructively when confronted with such an issue.

An Innovative Unmanned System for Advanced Environmental Monitoring: Design and Development

NASA Astrophysics Data System (ADS)

Marsella, Ennio; Giordano, Laura; Evangelista, Lorenza; Iengo, Antonio; di Filippo, Alessandro; Coppola, Aniello

2015-04-01

The paper summarizes the design and development of a new technology and tools for real-time coordination and control of unmanned vehicles for advanced environmental monitoring. A new Unmanned System has been developed at Institute for Coastal Marine Environmental - National Research Council (Italy), in the framework of two National Operational Programs (PON): Technological Platform for Geophysical and Environmental Marine Survey-PITAM and Integrated Systems and Technologies for Geophysical and Environmental Monitoring in coastal-marine areas-STIGEAC. In particular, the system includes one Unmanned Aerial Vehicle (UAV) and two Unmanned Marine Vehicles (UMV). Major innovations concern the implementation of a new architecture to control each drone and/or to allow the cooperation between heterogeneous vehicles, the integration of distributed sensing techniques and real-time image processing capabilities. Part of the research in these projects involves, therefore, an architecture, where the ground operator can communicate with the Unmanned Vehicles at various levels of abstraction using pointing devices and video viewing. In detail, a Ground Control Station (GCS) has been design and developed to allow the government in security of the drones within a distance up to twenty kilometers for air explorations and within ten nautical miles for marine activities. The Ground Control Station has the following features: 1. hardware / software system for the definition of the mission profiles; 3. autonomous and semi-autonomous control system by remote control (joystick or other) for the UAV and UMVs; 4. integrated control system with comprehensive visualization capabilities, monitoring and archiving of real-time data acquired from scientific payload; 5. open structure to future additions of systems, sensors and / or additional vehicles. In detail, the UAV architecture is a dual-rotor, with an endurance ranging from 55 to 200 minutes, depending on payload weight (maximum 26 kg) and

Ocean barrier layers’ effect on tropical cyclone intensification

PubMed Central

Balaguru, Karthik; Chang, Ping; Saravanan, R.; Leung, L. Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-01-01

Improving a tropical cyclone’s forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone’s path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are “quasi-permanent” features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity. PMID:22891298

Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balaguru, Karthik; Chang, P.; Saravanan, R.

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropicalmore » cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.« less

Homoepitaxial graphene tunnel barriers for spin transport

NASA Astrophysics Data System (ADS)

Friedman, Adam

Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions (magnetic field, temperature, etc.) usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. We demonstrate successful tunneling, charge, and spin transport with a fluorinated graphene tunnel barrier on a graphene channel. We show that while spin transport stops short of room temperature, spin polarization efficiency values are the highest of any graphene spin devices. We also demonstrate that hydrogenation of graphene can also be used to create a tunnel barrier. We begin with a four-layer stack of graphene and hydrogenate the top few layers to decouple them from the graphene transport channel beneath. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures and determine spin lifetimes with the non-local Hanle effect to be commensurate with previous studies. The measured spin polarization efficiencies for hydrogenated graphene are higher than most oxide tunnel barriers on graphene, but not as high as with fluorinated graphene tunnel barriers. However, here we show that spin transport persists up to room temperature. Our results for the hydrogenated graphene tunnel barriers are compared with fluorinated tunnel barriers and we discuss the

Performance and Environmental Assessment of an Advanced Aircraft with Open Rotor Propulsion

NASA Technical Reports Server (NTRS)

Guynn, Mark D.; Berton, Jeffrey J.; Haller, William J.; Hendricks, Eric S.; Tong, Michael T.

2012-01-01

Application of high speed, advanced turboprops, or "propfans," to transonic transport aircraft received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Unfortunately, after fuel prices declined sharply there was no longer sufficient motivation to continue maturing this technology. Recent volatility in fuel prices and increasing concern for aviation s environmental impact, however, have renewed interest in unducted, open rotor propulsion. Because of the renewed interest in open rotor propulsion, the lack of publicly available up-to-date studies assessing its benefits, and NASA s focus on reducing fuel consumption, a preliminary aircraft system level study on open rotor propulsion was initiated to inform decisions concerning research in this area. New analysis processes were established to assess the characteristics of open rotor aircraft. These processes were then used to assess the performance, noise, and emissions characteristics of an advanced, single-aisle aircraft using open rotor propulsion. The results of this initial study indicate open rotor engines have the potential to provide significant reductions in fuel consumption and landing-takeoff cycle NOX emissions. Noise analysis of the study configuration indicates that an open rotor aircraft in the single-aisle class would be able to meet current noise regulations with margin.

Potential facilitators and barriers to adopting standard treatment guidelines in clinical practice.

PubMed

Sharma, Sangeeta; Pandit, Ajay; Tabassum, Fauzia

2017-04-18

Purpose The purpose of this paper is to assess medicines information sources accessed by clinicians, if sources differed in theory and practice and to find out the barriers and facilitators to effective guideline adoption. Design/methodology/approach In all, 183 doctors were surveyed. Barriers and facilitators were classified as: communication; potential adopters; innovation; organization characteristics and environmental/social/economic context. Findings Most of the clinicians accessed multiple information sources including standard treatment guidelines, but also consulted seniors/colleagues in practice. The top three factors influencing clinical practice guideline adoption were innovation characteristics, environmental context and individual characteristics. The respondents differed in the following areas: concerns about flexibility offered by the guideline; denying patients' individuality; professional autonomy; insights into gaps in current practice and evidence-based practice; changing practices with little or no benefit. Barriers included negative staff attitudes/beliefs, guideline integration into organizational structures/processes, time/resource constraints. Fearing third parties (government and insurance companies) restricting medicines reimbursement and poor liability protection offered by the guidelines emerged as the barriers. Facilitators include aligning organizational structures/processes with the innovation; providing leadership support to guide diffusion; increasing awareness and enabling early innovation during pre/in-service training, with regular feedback on outcomes and use. Practical implications Guideline adoption in clinical practice is partly within doctors' control. There are other key prevailing factors in the local context such as environmental, social context, professional and organizational culture affecting its adoption. Organizational policy and accreditation standards necessitating adherence can serve as a driver. Originality

Advancements in the maintenance of skin barrier/skin lipid composition and the involvement of metabolic enzymes.

PubMed

Cui, Le; Jia, Yan; Cheng, Zhi-Wei; Gao, Ying; Zhang, Gao-Lei; Li, Jing-Yi; He, Cong-Fen

2016-12-01

The human skin barrier has an important role in protection and defense, reflected not only in the ability to resist entry of harmful substances into the human body, but also in the ability to prevent loss of water and nutrients. Once the skin barrier is damaged, the skin may become dry, scaly, and wrinkled, and a series of skin problems may occur. In this article, we review the composition of lipids, such as ceramides, cholesterol, and free fatty acids, in the skin and examine the expression of enzymes related to lipid metabolism, such as kallikreins, elongase of elongation of very long-chain fatty acids, hydrolases, and lipid synthases. Additionally, we discuss the involvement of these proteins in skin barrier function and structure. The information presented in this review is expected to provide a theoretical basis for the development of skin care products facilitating the maintenance and repair of skin barrier function. © 2016 Wiley Periodicals, Inc.

Environmental Research At The Advanced Photon Source

EPA Science Inventory

Because of the importance of probing molecular-scale chemical and physical structure of environmental samples in their natural and often hydrated state, synchrotron radiation has been a powerful tool for environmental scientists for decades. Thus, the crucial role that a highly ...

Barriers and Strategies in Guideline Implementation—A Scoping Review

PubMed Central

Fischer, Florian; Lange, Kerstin; Klose, Kristina; Greiner, Wolfgang; Kraemer, Alexander

2016-01-01

Research indicates that clinical guidelines are often not applied. The success of their implementation depends on the consideration of a variety of barriers and the use of adequate strategies to overcome them. Therefore, this scoping review aims to describe and categorize the most important barriers to guideline implementation. Furthermore, it provides an overview of different kinds of suitable strategies that are tailored to overcome these barriers. The search algorithm led to the identification of 1659 articles in PubMed. Overall, 69 articles were included in the data synthesis. The content of these articles was analysed by using a qualitative synthesis approach, to extract the most important information on barriers and strategies. The barriers to guideline implementation can be differentiated into personal factors, guideline-related factors, and external factors. The scoping review revealed the following aspects as central elements of successful strategies for guideline implementation: dissemination, education and training, social interaction, decision support systems and standing orders. Available evidence indicates that a structured implementation can improve adherence to guidelines. Therefore, the barriers to guideline implementation and adherence need to be analysed in advance so that strategies that are tailored to the specific setting and target groups can be developed. PMID:27417624

76 FR 8709 - Environmental Impact Statement; Proposed Cattle Fever Tick Control Barrier in South Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-15

... tick control barrier using game fencing to keep cattle fever ticks and southern cattle ticks out of... zone include horseback patrols, a segmented barrier consisting of game fencing, and treatments applied... determined that the installation of additional game fencing in the permanent quarantine zone would...

Advances in applications of rhamnolipids biosurfactant in environmental remediation: A review.

PubMed

Liu, Guansheng; Zhong, Hua; Yang, Xin; Liu, Yang; Shao, Binbin; Liu, Zhifeng

2018-04-01

The objective of this review is to provide a comprehensive overview of the advances in the applications of rhamnolipids biosurfactants in soil and ground water remediation for removal of petroleum hydrocarbon and heavy metal contaminants. The properties of rhamnolipids associated with the contaminant removal, that is, solubilization, emulsification, dispersion, foaming, wetting, complexation, and the ability to modify bacterial cell surface properties, were reviewed in the first place. Then current remediation technologies with integration of rhamnolipid were summarized, and the effects and mechanisms for rhamnolipid to facilitate contaminant removal for these technologies were discussed. Finally rhamnolipid-based methods for remediation of the sites co-contaminated by petroleum hydrocarbons and heavy metals were presented and discussed. The review is expected to enhance our understanding on environmental aspects of rhamnolipid and provide some important information to guide the extending use of this fascinating chemical in remediation applications. © 2017 Wiley Periodicals, Inc.

A peptide hormone required for Casparian strip diffusion barrier formation in Arabidopsis roots.

PubMed

Nakayama, Takuya; Shinohara, Hidefumi; Tanaka, Mina; Baba, Koki; Ogawa-Ohnishi, Mari; Matsubayashi, Yoshikatsu

2017-01-20

Plants achieve mineral ion homeostasis by means of a hydrophobic barrier on endodermal cells called the Casparian strip, which restricts lateral diffusion of ions between the root vascular bundles and the soil. We identified a family of sulfated peptides required for contiguous Casparian strip formation in Arabidopsis roots. These peptide hormones, which we named Casparian strip integrity factor 1 (CIF1) and CIF2, are expressed in the root stele and specifically bind the endodermis-expressed leucine-rich repeat receptor kinase GASSHO1 (GSO1)/SCHENGEN3 and its homolog, GSO2. A mutant devoid of CIF peptides is defective in ion homeostasis in the xylem. CIF genes are environmentally responsive. Casparian strip regulation is not merely a passive process driven by root developmental cues; it also serves as an active strategy to cope with adverse soil conditions. Copyright © 2017, American Association for the Advancement of Science.

Thermal Conductivity and Stability of HfO2-Y2O3 and La2Zr2O7 Evaluated for 1650 Deg C Thermal/Environmental Barrier Coating Applications

NASA Technical Reports Server (NTRS)

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

2003-01-01

HfO2-Y2O3 and La2Zr2O7 are candidate thermal and environmental barrier coating (T/EBC) materials for gas turbine ceramic matrix composite (CMC) combustor applications because of their relatively low thermal conductivity and high temperature capability. In this paper, thermal conductivity and high temperature stability of hot-pressed and plasma sprayed specimens with representative partially-stabilized and fully-cubic HfO2-Y2O3 compositions and La2Zr2O7 were evaluated at temperatures up to 1700 C using a steady-state laser heat-flux technique. Sintering behavior of the plasmasprayed coatings was determined by monitoring the thermal conductivity increases during a 20-hour test period at various temperatures. Durability and failure mechanisms of the HfO2-Y2O3 and La2Zr2O7 coatings on mullite/SiC hexoloy or SiC/SiC CMC substrates were investigated at 1650 C under thermal gradient cyclic conditions. Coating design and testing issues for the 1650 C thermal/environmental barrier coating applications are also discussed.

Flow directionality, mountain barriers and functional traits determine diatom metacommunity structuring of high mountain streams.

PubMed

Dong, Xiaoyu; Li, Bin; He, Fengzhi; Gu, Yuan; Sun, Meiqin; Zhang, Haomiao; Tan, Lu; Xiao, Wen; Liu, Shuoran; Cai, Qinghua

2016-04-19

Stream metacommunities are structured by a combination of local (environmental filtering) and regional (dispersal) processes. The unique characters of high mountain streams could potentially determine metacommunity structuring, which is currently poorly understood. Aiming at understanding how these characters influenced metacommunity structuring, we explored the relative importance of local environmental conditions and various dispersal processes, including through geographical (overland), topographical (across mountain barriers) and network (along flow direction) pathways in shaping benthic diatom communities. From a trait perspective, diatoms were categorized into high-profile, low-profile and motile guild to examine the roles of functional traits. Our results indicated that both environmental filtering and dispersal processes influenced metacommunity structuring, with dispersal contributing more than environmental processes. Among the three pathways, stream corridors were primary pathway. Deconstructive analysis suggested different responses to environmental and spatial factors for each of three ecological guilds. However, regardless of traits, dispersal among streams was limited by mountain barriers, while dispersal along stream was promoted by rushing flow in high mountain stream. Our results highlighted that directional processes had prevailing effects on metacommunity structuring in high mountain streams. Flow directionality, mountain barriers and ecological guilds contributed to a better understanding of the roles that mountains played in structuring metacommunity.

Furnace Cyclic Oxidation Behavior of Multi-Component Low Conductivity Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dong-Ming; Nesbitt, James A.; Barrett, Charles A.; McCue, Terry R.; Miller, Robert A.

2004-01-01

Ceramic thermal barrier coatings will play an increasingly important role in advanced gas turbine engines because of their ability to further increase engine operating temperatures and reduce cooling, thus helping achieve future engine low emission, high efficiency and improved reliability goals. Advanced multi-component zirconia-based thermal barrier coatings are being developed using an oxide defect clustering design approach to achieve the required coating low thermal conductivity and high temperature stability. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of the candidate coating materials was conducted using conventional furnace cyclic oxidation tests. In this paper, furnace cyclic oxidation behavior of plasma-sprayed zirconia-based defect cluster thermal barrier coatings was investigated at 1163 C using 45 min hot cycles. The ceramic coating failure mechanisms were studied using scanning electron microscopy (SEM) combined with X-ray diffraction (XRD) phase analysis after the furnace tests. The coating cyclic lifetime is also discussed in relation to coating processing, phase structures, dopant concentration, and other thermo-physical properties.

A CFD-Based Study of the Feasibility of Adapting an Erosion Burner Rig for Examining the Effect of CMAS Deposition Corrosion on Environmental Barrier Coatings

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria A.

2015-01-01

Thermodynamic and computational fluid dynamics modeling has been conducted to examine the feasibility of adapting the NASA-Glenn erosion burner rigs for use in studies of corrosion of environmental barrier coatings by the deposition of molten CMAS. The effect of burner temperature, Mach number, particle preheat, duct heating, particle size, and particle phase (crystalline vs. glass) were analyzed. Detailed strategies for achieving complete melting of CMAS particles were developed, thereby greatly improving the probability of future successful experimental outcomes.

EPS in Environmental Microbial Biofilms as Examined by Advanced Imaging Techniques

NASA Astrophysics Data System (ADS)

Neu, T. R.; Lawrence, J. R.

2006-12-01

Biofilm communities are highly structured associations of cellular and polymeric components which are involved in biogenic and geogenic environmental processes. Furthermore, biofilms are also important in medical (infection), industrial (biofouling) and technological (biofilm engineering) processes. The interfacial microbial communities in a specific habitat are highly dynamic and change according to the environmental parameters affecting not only the cellular but also the polymeric constituents of the system. Through their EPS biofilms interact with dissolved, colloidal and particulate compounds from the bulk water phase. For a long time the focus in biofilm research was on the cellular constituents in biofilms and the polymer matrix in biofilms has been rather neglected. The polymer matrix is produced not only by different bacteria and archaea but also by eukaryotic micro-organisms such as algae and fungi. The mostly unidentified mixture of EPS compounds is responsible for many biofilm properties and is involved in biofilm functionality. The chemistry of the EPS matrix represents a mixture of polymers including polysaccharides, proteins, nucleic acids, neutral polymers, charged polymers, amphiphilic polymers and refractory microbial polymers. The analysis of the EPS may be done destructively by means of extraction and subsequent chemical analysis or in situ by means of specific probes in combination with advanced imaging. In the last 15 years laser scanning microscopy (LSM) has been established as an indispensable technique for studying microbial communities. LSM with 1-photon and 2-photon excitation in combination with fluorescence techniques allows 3-dimensional investigation of fully hydrated, living biofilm systems. This approach is able to reveal data on biofilm structural features as well as biofilm processes and interactions. The fluorescent probes available allow the quantitative assessment of cellular as well as polymer distribution. For this purpose

Unwilling Brides: "Phallic Attack" as a Barrier to Gender Balance in Higher Education in Nigeria

ERIC Educational Resources Information Center

Nwadigwe, Charles E.

2007-01-01

Gender balance in access to quality education is a crucial item on the agenda of the Millennium Development Goals. But this ideal appears beset by a number of barriers, especially at higher education level. This study investigated the problem of sexual harassment in the Nigerian university system as a barrier to the educational advancement of…

ENVIRONMENTAL CHEMISTRY

EPA Science Inventory

Environmental chemistry is applied to estimating the exposure of ecosystems and humans to various chemical environmental stressors. Among the stressors of concern are mercury, pesticides, and arsenic. Advanced analytical chemistry techniques are used to measure these stressors ...

Do Associations Between Perceived Environmental and Individual Characteristics and Walking Limitations Depend on Lower Extremity Performance Level?

PubMed

Sakari, Ritva; Rantakokko, Merja; Portegijs, Erja; Iwarsson, Susanne; Sipilä, Sarianna; Viljanen, Anne; Rantanen, Taina

2017-06-01

The aim of this study was to analyze whether the associations between perceived environmental and individual characteristics and perceived walking limitations in older people differ between those with intact and those with poorer lower extremity performance. Persons aged 75 to 90 ( N = 834) participated in interviews and performance tests in their homes. Standard questionnaires were used to obtain walking difficulties; environmental barriers to and, facilitators of, mobility; and perceived individual hindrances to outdoor mobility. Lower extremity performance was tested using Short Physical Performance Battery (SPPB). Among those with poorer lower extremity performance, the likelihood for advanced walking limitations was, in particular, related to perceived poor safety in the environment, and among those with intact performance to perceived social issues, such as lack of company, as well as to long distances. The environmental correlates of walking limitations seem to depend on the level of lower extremity performance.

Homoepitaxial graphene tunnel barriers for spin transport

NASA Astrophysics Data System (ADS)

Friedman, Adam L.; van't Erve, Olaf M. J.; Robinson, Jeremy T.; Whitener, Keith E.; Jonker, Berend T.

2016-05-01

Tunnel barriers are key elements for both charge-and spin-based electronics, offering devices with reduced power consumption and new paradigms for information processing. Such devices require mating dissimilar materials, raising issues of heteroepitaxy, interface stability, and electronic states that severely complicate fabrication and compromise performance. Graphene is the perfect tunnel barrier. It is an insulator out-of-plane, possesses a defect-free, linear habit, and is impervious to interdiffusion. Nonetheless, true tunneling between two stacked graphene layers is not possible in environmental conditions usable for electronics applications. However, two stacked graphene layers can be decoupled using chemical functionalization. Here, we demonstrate that hydrogenation or fluorination of graphene can be used to create a tunnel barrier. We demonstrate successful tunneling by measuring non-linear IV curves and a weakly temperature dependent zero-bias resistance. We demonstrate lateral transport of spin currents in non-local spin-valve structures, and determine spin lifetimes with the non-local Hanle effect. We compare the results for hydrogenated and fluorinated tunnel and we discuss the possibility that ferromagnetic moments in the hydrogenated graphene tunnel barrier affect the spin transport of our devices.

Identifying the Factors That Facilitate or Hinder Advance Planning by Persons With Dementia

PubMed Central

Hirschman, Karen B.; Kapo, Jennifer M.; Karlawish, Jason H. T.

2009-01-01

We performed semistructured interviews with 30 family members of patients with advanced dementia to identify the factors that facilitate or hinder advance planning by persons with dementia. All interviews were analyzed using qualitative data analysis techniques. The majority (77%) of family members reported that their relative had some form of written advance directive, and at least half reported previous discussions about health care preferences (57%), living situation or placement issues (50%), and finances or estate planning (60%) with the patient. Family members reported some themes that prompted planning and others that were barriers to planning. Events that most often triggered planning were medical, living situation, or financial issues associated with a friend or family member of the patient (57%). Barriers to planning included both passive and active avoidance. The most common form of passive avoidance was not realizing the importance of planning until it was too late to have the discussion (63%). The most common form of active avoidance was avoiding the discussion (53%). These data suggest potentially remediable strategies to address barriers to advance planning discussions. PMID:18580595

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soria-Lara, Julio A., E-mail: j.a.sorialara@uva.nl; Bertolini, Luca, E-mail: l.bertolini@uva.nl; Brömmelstroet, Marco te, E-mail: M.C.G.teBrommelstroet@uva.nl

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 themore » 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.« less

Responsible Environmental Action: Its Role and Status in Environmental Education and Environmental Quality

ERIC Educational Resources Information Center

Short, Philip C.

2009-01-01

This century will be one of continued global population growth, technological advancement, and subsequent burdens on the natural world from consumer demands. A citizenry capable of understanding the complexity of environmental issues and actively participating in their resolutions is vital. The ultimate goal of environmental educators should be to…

The Development of Erosion and Impact Resistant Turbine Airfoil Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Miller, Robert A.

2007-01-01

Thermal barrier coatings are used in gas turbine engines to protect engine hot-section components in the harsh combustion environments and extend component lifetimes. For thermal barrier coatings designed for turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability. Advanced erosion resistant thermal barrier coatings are being developed, with a current emphasis on the toughness improvements using a combined rare earth- and transition metal-oxide doping approach. The performance of the doped thermal barrier coatings has been evaluated in burner rig and laser heat-flux rig simulated engine erosion and thermal gradient environments. The results have shown that the coating composition optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic durability. The erosion and impact damage mechanisms of the thermal barrier coatings will also be discussed.

Environmental factors and their role in community integration after spinal cord injury.

PubMed

Lysack, Cathy; Komanecky, Marie; Kabel, Allison; Cross, Katherine; Neufeld, Stewart

2007-01-01

The International Classification of Functioning, Disability and Health (ICF) model presents an opportunity to better understand previously neglected longterm social outcomes after traumatic spinal cord injury (SCI), especially the experience of participation. The study explored the relationship between perceived environmental barriers and perceived community integration (a participation proxy) in a sample of adults with traumatic SCI. The study interviewed African American and White women and men (n = 136) who had lived with SCI for an average of 11.5 years. Participants reported environmental barriers at twice the level indicated by previous studies; the natural environment and the policies of government were the most problematic. Levels of community integration were also high. Data suggest a significant relationship (p < .01) between perceived environmental barriers and community integration for adults with SCI, providing support for the ICF model. Improved measures and more sophisticated concepts and theories are needed to explicate the relationship between environmental factors and participation concepts in the ICE With respect to practice, occupational therapists need to be aware that removal of environmental barriers is only a first step in the more complex effort to facilitate optimal community integration after SCI.

Advances in shrub-willow crops for bioenergy, renewable products, and environmental benefits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Volk, Timothy A.; Heavey, Justin P.; Eisenbies, Mark H.

Short-rotation coppice systems like shrub willow are projected to be an important source of biomass in the United States for the production of bioenergy, biofuels, and renewable bio-based products, with the potential for auxiliary environmental benefits and multifunctional systems. Almost three decades of research has focused on the development of shrub willow crops for biomass and ecosystem services. The current expansion of willow in New York State (about 500 ha) for the production of renewable power and heat has been possible because of incentive programs offered by the federal government, commitments by end users, the development of reliable harvesting systems,more » and extension services offered to growers. Improvements in the economics of the system are expected as willow production expands further, which should help lower establishment costs, enhance crop management options and increase efficiencies in harvesting and logistics. As a result, deploying willow in multifunctional value-added systems provides opportunities for both potential producers and end users to learn about the system and the quality of the biomass feedstock, which in turn will help overcome barriers to expansion.« less

Advances in shrub-willow crops for bioenergy, renewable products, and environmental benefits

DOE PAGES

Volk, Timothy A.; Heavey, Justin P.; Eisenbies, Mark H.

2016-05-02

Short-rotation coppice systems like shrub willow are projected to be an important source of biomass in the United States for the production of bioenergy, biofuels, and renewable bio-based products, with the potential for auxiliary environmental benefits and multifunctional systems. Almost three decades of research has focused on the development of shrub willow crops for biomass and ecosystem services. The current expansion of willow in New York State (about 500 ha) for the production of renewable power and heat has been possible because of incentive programs offered by the federal government, commitments by end users, the development of reliable harvesting systems,more » and extension services offered to growers. Improvements in the economics of the system are expected as willow production expands further, which should help lower establishment costs, enhance crop management options and increase efficiencies in harvesting and logistics. As a result, deploying willow in multifunctional value-added systems provides opportunities for both potential producers and end users to learn about the system and the quality of the biomass feedstock, which in turn will help overcome barriers to expansion.« less

Introduction for the special issue on recent advances in drug delivery across tissue barriers.

PubMed

Mrsny, Randall J; Brayden, David J

2016-01-01

This special issue of Tissue Barriers contains a series of reviews with the common theme of how biological barriers established at epithelial tissues limit the uptake of macromolecular therapeutics. By improving our functional understanding of these barriers, the majority of the authors have highlighted potential strategies that might be applied to the non-invasive delivery of biopharmaceuticals that would otherwise require an injection format for administration. Half of the articles focus on the potential of particular technologies to assist oral delivery of peptides, proteins and other macromolecules. These include use of prodrug chemistry to improve molecule stability and permeability, and the related potential for oral delivery of poorly permeable agents by cell-penetrating peptides and dendrimers. Safety aspects of intestinal permeation enhancers are discussed, along with the more recent foray into drug-device combinations as represented by intestinal microneedles and externally-applied ultrasound. Other articles highlight the crossover between food research and oral delivery based on nanoparticle technology, while the final one provides a fascinating interpretation of the physiological problems associated with subcutaneous insulin delivery and how inefficient it is at targeting the liver.

Environmental problem solving

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, A.

Human influences create both environmental problems and barriers to effective policy aimed at addressing those problems. In effect, environmental managers manage people as much as they manage the environment. Therefore, they must gain an understanding of the psychological and sociopolitical dimensions of environmental problems that they are attempting to resolve. The author reappraises conventional analyses of environmental problems using lessons from the psychosocial disciplines. The author combines the disciplines of ecology, political sociology and psychology to produce a more adaptive approach to problem-solving that is specifically geared toward the environmental field. Numerous case studies demonstrate the practical application of theorymore » in a way that is useful to technical and scientific professionals as well as to policymakers and planners.« less

A design perspective on thermal barrier coatings

NASA Astrophysics Data System (ADS)

Soechting, F. O.

1999-12-01

This article addresses the challenges for maximizing the benefit of thermal barrier coatings for turbine engine applications. The perspective is from the viewpoint of a customer, a turbine airfoil designer who is continuously challenged to increase the turbine inlet temperature capability for new products while maintaining cooling flow levels or even reducing them. This is a fundamental requirement for achieving increased engine thrust levels. Developing advanced material systems for the turbine flowpath airfoils, such as high-temperature nickel-base superalloys or thermal barrier coatings to insulate the metal airfoils from the hot flowpath environment, is one approach to solve this challenge. The second approach is to increase the cooling performance of the turbine airfoil, which enables increased flowpath temperatures and reduced cooling flow levels. Thermal barrier coatings have been employed in jet engine applications for almost 30 years. The initial application was on augmentor liners to provide thermal protection during afterburner operation. However, the production use of thermal barrier coatings in the turbine section has only occurred in the past 15 years. The application was limited to stationary parts and only recently incorporated on the rotating turbine blades. This lack of endorsement of thermal barrier coatings resulted from the poor initial duratbility of these coatings in high heat flux environments. Significant improvements have been made to enhance spallation resistance and erosion resistance, which has resulted in increased reliability of these coatings in turbine applications.

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.

Advances in Male Contraception

PubMed Central

Page, Stephanie T.; Amory, John K.; Bremner, William J.

2008-01-01

Despite significant advances in contraceptive options for women over the last 50 yr, world population continues to grow rapidly. Scientists and activists alike point to the devastating environmental impacts that population pressures have caused, including global warming from the developed world and hunger and disease in less developed areas. Moreover, almost half of all pregnancies are still unwanted or unplanned. Clearly, there is a need for expanded, reversible, contraceptive options. Multicultural surveys demonstrate the willingness of men to participate in contraception and their female partners to trust them to do so. Notwithstanding their paucity of options, male methods including vasectomy and condoms account for almost one third of contraceptive use in the United States and other countries. Recent international clinical research efforts have demonstrated high efficacy rates (90–95%) for hormonally based male contraceptives. Current barriers to expanded use include limited delivery methods and perceived regulatory obstacles, which stymie introduction to the marketplace. However, advances in oral and injectable androgen delivery are cause for optimism that these hurdles may be overcome. Nonhormonal methods, such as compounds that target sperm motility, are attractive in their theoretical promise of specificity for the reproductive tract. Gene and protein array technologies continue to identify potential targets for this approach. Such nonhormonal agents will likely reach clinical trials in the near future. Great strides have been made in understanding male reproductive physiology; the combined efforts of scientists, clinicians, industry and governmental funding agencies could make an effective, reversible, male contraceptive an option for family planning over the next decade. PMID:18436704

Breaking through Barriers: AAUW Annual Report Fiscal Year 2008

ERIC Educational Resources Information Center

American Association of University Women, 2008

2008-01-01

The American Association of University Women (AAUW) advances equity for women and girls through advocacy, education, and research. In principle and in practice, AAUW values and seeks a diverse membership. There shall be no barriers to full participation in this organization on the basis of gender, race, creed, age, sexual orientation, national…

Multisectoral Strategies for Advancing Girls' Education: Principles and Practice. SAGE Technical Report.

ERIC Educational Resources Information Center

Williams, Howard

This paper describes issues, experiences, and strategies used in developing successful multisectoral partnerships to advance girls' education, using Guinea and Morocco as examples. Chapter 1 introduces the issue, discussing barriers to girls' education and describing the multisectoral response to interrelated barriers. Chapter 2 defines the…

Recent advancements in liposomes targeting strategies to cross blood-brain barrier (BBB) for the treatment of Alzheimer's disease.

PubMed

Agrawal, Mukta; Ajazuddin; Tripathi, Dulal K; Saraf, Swarnlata; Saraf, Shailendra; Antimisiaris, Sophia G; Mourtas, Spyridon; Hammarlund-Udenaes, Margareta; Alexander, Amit

2017-08-28

In this modern era, with the help of various advanced technologies, medical science has overcome most of the health-related issues successfully. Though, some diseases still remain unresolved due to various physiological barriers. One such condition is Alzheimer; a neurodegenerative disorder characterized by progressive memory impairment, behavioral abnormalities, mood swing and disturbed routine activities of the person suffering from. It is well known to all that the brain is entirely covered by a protective layer commonly known as blood brain barrier (BBB) which is responsible to maintain the homeostasis of brain by restricting the entry of toxic substances, drug molecules, various proteins and peptides, small hydrophilic molecules, large lipophilic substances and so many other peripheral components to protect the brain from any harmful stimuli. This functionally essential structure creates a major hurdle for delivery of any drug into the brain. Still, there are some provisions on BBB which facilitate the entry of useful substances in the brain via specific mechanisms like passive diffusion, receptor-mediated transcytosis, carrier-mediated transcytosis etc. Another important factor for drug transport is the selection of a suitable drug delivery systems like, liposome, which is a novel drug carrier system offering a potential approach to resolving this problem. Its unique phospholipid bilayer structure (similar to physiological membrane) had made it more compatible with the lipoidal layer of BBB and helps the drug to enter the brain. The present review work focused on various surface modifications with functional ligand (like lactoferrin, transferrin etc.) and carrier molecules (such as glutathione, glucose etc.) on the liposomal structure to enhance its brain targeting ability towards the successful treatment of Alzheimer disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Physiology and immunology of mucosal barriers in catfish (Ictalurus spp.)

USDA-ARS?s Scientific Manuscript database

The mucosal barriers of catfish (Ictalurus spp.) constitute the first line of defense against pathogen invasion while simultaneously carrying out a diverse array of other critical physiological processes, including nutrient adsorption, osmoregulation, waste excretion, and environmental sensing. Catf...

Imaging approach to mechanistic study of nanoparticle interactions with the blood-brain barrier.

PubMed

Bramini, Mattia; Ye, Dong; Hallerbach, Anna; Nic Raghnaill, Michelle; Salvati, Anna; Aberg, Christoffer; Dawson, Kenneth A

2014-05-27

Understanding nanoparticle interactions with the central nervous system, in particular the blood-brain barrier, is key to advances in therapeutics, as well as assessing the safety of nanoparticles. Challenges in achieving insights have been significant, even for relatively simple models. Here we use a combination of live cell imaging and computational analysis to directly study nanoparticle translocation across a human in vitro blood-brain barrier model. This approach allows us to identify and avoid problems in more conventional inferential in vitro measurements by identifying the catalogue of events of barrier internalization and translocation as they occur. Potentially this approach opens up the window of applicability of in vitro models, thereby enabling in depth mechanistic studies in the future. Model nanoparticles are used to illustrate the method. For those, we find that translocation, though rare, appears to take place. On the other hand, barrier uptake is efficient, and since barrier export is small, there is significant accumulation within the barrier.

Area Reports. Advanced materials and devices research area. Silicon materials research task, and advanced silicon sheet task

NASA Technical Reports Server (NTRS)

1986-01-01

The objectives of the Silicon Materials Task and the Advanced Silicon Sheet Task are to identify the critical technical barriers to low-cost silicon purification and sheet growth that must be overcome to produce a PV cell substrate material at a price consistent with Flat-plate Solar Array (FSA) Project objectives and to overcome these barriers by performing and supporting appropriate R&D. Progress reports are given on silicon refinement using silane, a chemical vapor transport process for purifying metallurgical grade silicon, silicon particle growth research, and modeling of silane pyrolysis in fluidized-bed reactors.

Defect Clustering and Nano-phase Structure Characterization of Multicomponent Rare Earth-Oxide-Doped Zirconia-Yttria Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Chen, Yuan L.; Miller, Robert A.

2004-01-01

Advanced thermal barrier coatings (TBCs) have been developed by incorporating multicomponent rare earth oxide dopants into zirconia-based thermal barrier coatings to promote the creation of the thermodynamically stable, immobile oxide defect clusters and/or nanophases within the coating systems. In this paper, the defect clusters, induced by Nd, Gd, and Yb rare earth dopants in the zirconia-yttria thermal barrier coatings, were characterized by high-resolution transmission electron microscopy (TEM). The TEM lattice imaging, selected area diffraction (SAD), and electron energy-loss spectroscopy (EELS) analyses demonstrated that the extensive nanoscale rare earth dopant segregation exists in the plasma-sprayed and electron-physical-vapor-deposited (EB PVD) thermal barrier coatings. The nanoscale concentration heterogeneity and the resulting large lattice distortion promoted the formation of parallel and rotational defective lattice clusters in the coating systems. The presence of the 5-to 100-nm-sized defect clusters and nanophases is believed to be responsible for the significant reduction of thermal conductivity, improved sintering resistance, and long-term high temperature stability of the advanced thermal barrier coating systems.

Healthcare librarians and the delivery of critical appraisal training: barriers to involvement.

PubMed

Maden-Jenkins, Michelle

2011-03-01

  Many healthcare librarians are undertaking training in critical appraisal but a significant number are not cascading the training to their end-users.   To examine the barriers to healthcare librarian involvement in delivering critical appraisal training.   A questionnaire survey of 57 library services across 48 NHS Trust Library Services in north west England followed up with 21 semi-structured interviews.   Two types of barriers were noted: extrinsic barriers (organisational, environmental, training, role expectations) and intrinsic barriers (knowledge, skills, attitude).   These barriers are not mutually exclusive and by overcoming one of them it does not necessarily follow that healthcare librarians will engage in delivering critical appraisal skills training. The challenge lies in developing strategies to deal effectively with these barriers to encourage and support healthcare librarians in the delivery of critical appraisal training at a level at which they feel confident and able. © 2010 The authors. Health Information and Libraries Journal © 2010 Health Libraries Group.

Blood-brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders.

PubMed

Fiorentino, Maria; Sapone, Anna; Senger, Stefania; Camhi, Stephanie S; Kadzielski, Sarah M; Buie, Timothy M; Kelly, Deanna L; Cascella, Nicola; Fasano, Alessio

2016-01-01

Autism spectrum disorders (ASD) are complex conditions whose pathogenesis may be attributed to gene-environment interactions. There are no definitive mechanisms explaining how environmental triggers can lead to ASD although the involvement of inflammation and immunity has been suggested. Inappropriate antigen trafficking through an impaired intestinal barrier, followed by passage of these antigens or immune-activated complexes through a permissive blood-brain barrier (BBB), can be part of the chain of events leading to these disorders. Our goal was to investigate whether an altered BBB and gut permeability is part of the pathophysiology of ASD. Postmortem cerebral cortex and cerebellum tissues from ASD, schizophrenia (SCZ), and healthy subjects (HC) and duodenal biopsies from ASD and HC were analyzed for gene and protein expression profiles. Tight junctions and other key molecules associated with the neurovascular unit integrity and function and neuroinflammation were investigated. Claudin ( CLDN )-5 and -12 were increased in the ASD cortex and cerebellum. CLDN-3 , tricellulin , and MMP-9 were higher in the ASD cortex. IL-8 , tPA , and IBA-1 were downregulated in SCZ cortex; IL-1b was increased in the SCZ cerebellum. Differences between SCZ and ASD were observed for most of the genes analyzed in both brain areas. CLDN-5 protein was increased in ASD cortex and cerebellum, while CLDN-12 appeared reduced in both ASD and SCZ cortexes. In the intestine, 75% of the ASD samples analyzed had reduced expression of barrier-forming TJ components ( CLDN-1 , OCLN , TRIC ), whereas 66% had increased pore-forming CLDNs ( CLDN-2 , -10 , -15 ) compared to controls. In the ASD brain, there is an altered expression of genes associated with BBB integrity coupled with increased neuroinflammation and possibly impaired gut barrier integrity. While these findings seem to be specific for ASD, the possibility of more distinct SCZ subgroups should be explored with additional studies.

HEURISTIC OPTIMIZATION AND ALGORITHM TUNING APPLIED TO SORPTIVE BARRIER DESIGN

EPA Science Inventory

While heuristic optimization is applied in environmental applications, ad-hoc algorithm configuration is typical. We use a multi-layer sorptive barrier design problem as a benchmark for an algorithm-tuning procedure, as applied to three heuristics (genetic algorithms, simulated ...

Self-Perceptions of Value, Barriers, and Motivations for Graduate Education Among Dental Hygienists.

PubMed

Smith, Amy N; Boyd, Linda D; Rogers, Christine Macarelli; Le Jeune, Ronald C

2016-09-01

Increasing the knowledge base of its practitioners through formal education is vital to advancing the dental hygiene profession, ensuring practitioners' readiness for participation in future health care workforce models, and preparing future dental hygiene educators. The aim of this study was to discover the value of, barriers to, and motivations for graduate education among dental hygienists as a first step toward establishing ways to stimulate enrollment and facilitate program change. A qualitative pilot study design was used, with focus groups used for data collection. Four virtual focus groups were conducted on a video conferencing platform with dental hygienists (N=15) of varying educational levels residing in nine states. Focus group results were examined for emerging themes. The majority of participants placed a high value on graduate education as it related to expanding employment options and satisfying personal goals, but perceived it to have little value regarding advancement in clinical practice. Top barriers to education were reported to be time management, finances, and degree program options. Motivational themes for pursuing education included increased career options, benefits, and salary; personal satisfaction; potential to advance the profession; and financial support. The participants agreed that increased education can lead to more varied career opportunities and advance the profession, but their responses suggested limited motivation to pursue graduate studies. Determining ways to increase the value, reduce barriers, and enhance motivation for a graduate degree should be a priority of academic institutions and professional organizations involved in dental hygiene to ensure a workforce that is qualified for future health care initiatives and prepared to become educators.

[The significance of climate and environment protection for health under special consideration of skin barrier damages and allergic sequelae].

PubMed

Heuson, Clemens; Traidl-Hoffmann, Claudia

2018-06-01

The skin, together with gut and respiratory tract, harbor a central epithelial barrier function in regards to the interaction of an individual with the environment. Continuing exposure to environmental influences can cause epithelial barrier damages and thus pave the way for atopy development. The latter describes the tendency for allergies, i. e. hypersensitivity of the skin, intestine, and respiratory tract towards per se unharmful environmental substances.Allergies are classified as non-communicable diseases (NCDs). According to the World Health Organization (WHO), they are presently the most demanding medical challenge. Allergies are the most frequent NCDs and are characterized by a high and multi-facetted level of suffering. An enormous socio-economic burden and the urgent need for effective prevention follows as consequence. Prevention options have by no means been sufficiently used. Within the skin barrier's key function in regards to the defense of atopic diseases are so far inadequately used prevention possibilities. They are based on ambitious environmental and climatic policy that pointedly addresses the barrier disrupting environmental factors.On the basis of this proposition, the present article assigns appropriate environmental and climatic policy measures. The two main arguments for such measures are a disburdening of the healthcare system as well as a far better life quality for the affected people. They are the legitimization towards an ambitious environmental and climatic policy. For its realization an integrated approach of (allergy) prevention and environmental research is necessary. Now, campaigning for its acceptance in politics and society is an urgent matter.

Barriers to the conduct of randomised clinical trials within all disease areas.

PubMed

Djurisic, Snezana; Rath, Ana; Gaber, Sabrina; Garattini, Silvio; Bertele, Vittorio; Ngwabyt, Sandra-Nadia; Hivert, Virginie; Neugebauer, Edmund A M; Laville, Martine; Hiesmayr, Michael; Demotes-Mainard, Jacques; Kubiak, Christine; Jakobsen, Janus C; Gluud, Christian

2017-08-01

Randomised clinical trials are key to advancing medical knowledge and to enhancing patient care, but major barriers to their conduct exist. The present paper presents some of these barriers. We performed systematic literature searches and internal European Clinical Research Infrastructure Network (ECRIN) communications during face-to-face meetings and telephone conferences from 2013 to 2017 within the context of the ECRIN Integrating Activity (ECRIN-IA) project. The following barriers to randomised clinical trials were identified: inadequate knowledge of clinical research and trial methodology; lack of funding; excessive monitoring; restrictive privacy law and lack of transparency; complex regulatory requirements; and inadequate infrastructures. There is a need for more pragmatic randomised clinical trials conducted with low risks of systematic and random errors, and multinational cooperation is essential. The present paper presents major barriers to randomised clinical trials. It also underlines the value of using a pan-European-distributed infrastructure to help investigators overcome barriers for multi-country trials in any disease area.

Physicians' Views on Advance Care Planning and End-of-Life Care Conversations.

PubMed

Fulmer, Terry; Escobedo, Marcus; Berman, Amy; Koren, Mary Jane; Hernández, Sandra; Hult, Angela

2018-05-23

To evaluate physicians' views on advance care planning, goals of care, and end-of-life conversations. Random sample telephone survey. United States. Physicians (primary care specialists; pulmonology, cardiology, oncology subspecialists) actively practicing medicine and regularly seeing patients aged 65 and older (N=736; 81% male, 75% white, 66% aged ≥50. A 37-item telephone survey constructed by a professional polling group with national expert oversight measured attitudes and perceptions of barriers and facilitators to advance care planning. Summative data are presented here. Ninety-nine percent of participants agreed that it is important to have end-of-life conversations, yet only 29% reported that they have formal training for such conversations. Those most likely to have training included younger physicians and those caring for a racially and ethnically diverse population. Patient values and preferences were the strongest motivating factors in having advance care planning conversations, with 92% of participants rating it extremely important. Ninety-five percent of participants reported that they supported a new Medicare fee-for-service benefit reimbursing advance care planning. The biggest barrier mentioned was time availability. Other barriers included not wanting a patient to give up hope and feeling uncomfortable. With more than half of physicians reporting that they feel educationally unprepared, there medical school curricula need to be strengthened to ensure readiness for end-of-life conversations. Clinician barriers need to be addressed to meet the needs of older adults and families. Policies that focus on payment for quality should be evaluated at regular intervals to monitor their effect on advance care planning. © 2018, Copyright the Authors Journal compilation © 2018, The American Geriatrics Society.

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.

The Advanced Monitoring Systems Initiative--Performance Monitoring for DOE Environmental Remediation and Contaminant Containment

NASA Astrophysics Data System (ADS)

Haas, W. J.; Venedam, R. J.; Lohrstorfer, C. F.; Weeks, S. J.

2005-05-01

The Advanced Monitoring System Initiative (AMSI) is a new approach to accelerate the development and application of advanced sensors and monitoring systems in support of Department of Energy needs in monitoring the performance of environmental remediation and contaminant containment activities. The Nevada Site Office of the National Nuclear Security Administration (NNSA) and Bechtel Nevada manage AMSI, with funding provided by the DOE Office of Environmental Management (DOE EM). AMSI has easy access to unique facilities and capabilities available at the Nevada Test Site (NTS), including the Hazardous Materials (HazMat) Spill Center, a one-of-a-kind facility built and permitted for releases of hazardous materials for training purposes, field-test detection, plume dispersion experimentation, and equipment and materials testing under controlled conditions. AMSI also has easy access to the facilities and considerable capabilities of the DOE and NNSA National Laboratories, the Special Technologies Laboratory, Remote Sensing Laboratory, Desert Research Institute, and Nevada Universities. AMSI provides rapid prototyping, systems integration, and field-testing, including assistance during initial site deployment. The emphasis is on application. Important features of the AMSI approach are: (1) customer investment, involvement and commitment to use - including definition of needs, desired mode of operation, and performance requirements; and (2) employment of a complete systems engineering approach, which allows the developer to focus maximum attention on the essential new sensing element or elements while AMSI assumes principal responsibility for infrastructure support elements such as power, packaging, and general data acquisition, control, communication, visualization and analysis software for support of decisions. This presentation describes: (1) the needs for sensors and performance monitoring for environmental systems as seen by the DOE Long Term Stewardship Science and

Purpose, processes, partnerships, and products: four Ps to advance participatory socio-environmental modeling

USGS Publications Warehouse

Gray, Steven; Voinov, Alexey; Paolisso, Michael; Jordan, Rebecca; BenDor, Todd; Bommel, Pierre; Glynn, Pierre D.; Hedelin, Beatrice; Hubacek, Klaus; Introne, Josh; Kolagani, Nagesh; Laursen, Bethany; Prell, Christina; Schmitt-Olabisi, Laura; Singer, Alison; Sterling, Eleanor J.; Zellner, Moira

2018-01-01

Including stakeholders in environmental model building and analysis is an increasingly popular approach to understanding ecological change. This is because stakeholders often hold valuable knowledge about socio-environmental dynamics and collaborative forms of modeling produce important boundary objects used to collectively reason about environmental problems. Although the number of participatory modeling (PM) case studies and the number of researchers adopting these approaches has grown in recent years, the lack of standardized reporting and limited reproducibility have prevented PM's establishment and advancement as a cohesive field of study. We suggest a four-dimensional framework (4P) that includes reporting on dimensions of (1) the Purpose for selecting a PM approach (the why); (2) the Process by which the public was involved in model building or evaluation (the how); (3) the Partnerships formed (the who); and (4) the Products that resulted from these efforts (the what). We highlight four case studies that use common PM software-based approaches (fuzzy cognitive mapping, agent-based modeling, system dynamics, and participatory geospatial modeling) to understand human–environment interactions and the consequences of ecological changes, including bushmeat hunting in Tanzania and Cameroon, agricultural production and deforestation in Zambia, and groundwater management in India. We demonstrate how standardizing communication about PM case studies can lead to innovation and new insights about model-based reasoning in support of ecological policy development. We suggest that our 4P framework and reporting approach provides a way for new hypotheses to be identified and tested in the growing field of PM.

Purpose, processes, partnerships, and products: four Ps to advance participatory socio-environmental modeling.

PubMed

Gray, Steven; Voinov, Alexey; Paolisso, Michael; Jordan, Rebecca; BenDor, Todd; Bommel, Pierre; Glynn, Pierre; Hedelin, Beatrice; Hubacek, Klaus; Introne, Josh; Kolagani, Nagesh; Laursen, Bethany; Prell, Christina; Schmitt Olabisi, Laura; Singer, Alison; Sterling, Eleanor; Zellner, Moira

2018-01-01

Including stakeholders in environmental model building and analysis is an increasingly popular approach to understanding ecological change. This is because stakeholders often hold valuable knowledge about socio-environmental dynamics and collaborative forms of modeling produce important boundary objects used to collectively reason about environmental problems. Although the number of participatory modeling (PM) case studies and the number of researchers adopting these approaches has grown in recent years, the lack of standardized reporting and limited reproducibility have prevented PM's establishment and advancement as a cohesive field of study. We suggest a four-dimensional framework (4P) that includes reporting on dimensions of (1) the Purpose for selecting a PM approach (the why); (2) the Process by which the public was involved in model building or evaluation (the how); (3) the Partnerships formed (the who); and (4) the Products that resulted from these efforts (the what). We highlight four case studies that use common PM software-based approaches (fuzzy cognitive mapping, agent-based modeling, system dynamics, and participatory geospatial modeling) to understand human-environment interactions and the consequences of ecological changes, including bushmeat hunting in Tanzania and Cameroon, agricultural production and deforestation in Zambia, and groundwater management in India. We demonstrate how standardizing communication about PM case studies can lead to innovation and new insights about model-based reasoning in support of ecological policy development. We suggest that our 4P framework and reporting approach provides a way for new hypotheses to be identified and tested in the growing field of PM. © 2017 by the Ecological Society of America.

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.

Effect of glutamine-enriched nutritional support on intestinal mucosal barrier function, MMP-2, MMP-9 and immune function in patients with advanced gastric cancer during perioperative chemotherapy.

PubMed

Wang, Juan; Li, Yanfen; Qi, Yuanling

2017-09-01

We studied the effects of glutamine-enriched nutritional support on intestinal mucosal barrier, matrix metalloproteinase (MMP)-2, MMP-9 and immune function during perioperative chemotherapy in patients with advanced gastric cancer. The study was conducted on 94 patients with advanced gastric cancer admitted from April 2015 to March 2016. They were randomly divided into observation and control groups, n=47. Control group was given basic nutritional support whereas glutamine-enriched nutritional support was given to patients in observation group. High-performance liquid chromatography was used to measure lactulose and mannitol ratio in urine (L/M) and ELISA was used to measure D-lactate levels before chemotherapy and in the 1st, 2nd and 3rd cycle of chemotherapy. Immunoglobulin level was detected by immune turbidimetry assay, T lymphocyte subsets were determined by flow cytometry after 3 cycles of chemotherapy, MMP-2 and MMP-9 of patients were compared between the two groups. The serious adverse reactions incidence (grade and IV) of patients were observed. To evaluate the life quality of patients, QLQ-C30 was used after 6 months. The levels of L/M and D-lactate in both groups after the first cycle of chemotherapy were significantly higher than that before chemotherapy; they began to decline after the second or third cycle, but were still significantly higher than the levels before chemotherapy (p<0.05). On comparison, between the two groups after 1st, 2nd, 3rd cycle after chemotherapy, L/M and D-lactate levels of patients in the observation group were significantly lower than in the control group (p<0.05). Incidence of serious adverse reactions (grades III and IV) in observation group was significantly lower than control group (p<0.05). At follow-up of 6 months, living quality scores of patients in observation group were significantly higher than control group (p<0.05). Glutamine-enriched nutritional support can effectively protect the intestinal mucosal barrier

The feasibility of introducing advanced minimally invasive surgery into surgical practice

PubMed Central

Birch, Daniel W.; Misra, Monali; Farrokhyar, Forough

2007-01-01

Background This study investigates the feasibility of performing advanced minimally invasive surgery (MIS) in a nonspecialized practice environment. Methods We conducted a cross-sectional survey of all community general surgeons currently practising in Ontario. Results Few community surgeons perform a high volume (> 10 procedures per yr) of advanced MIS. Most (70%) believe it is important to acquire additional skills in advanced MIS. The most appropriate methods for learning advanced MIS are believed to be expert mentoring (79.7%), courses (77.2%) and a colleague mentor (63.9%). A total of 57.6% of respondents have attended a course in MIS while in practice, and most have access to a reasonable variety of instrumentation. Respondents believe that 57.6% of assistants, 54.8% of nurses and 43.4% of anaesthetists are relatively inexperienced with advanced MIS. Barriers to establishing advanced MIS include limited operating room access (50%), resources or equipment (45.2%) and limited expert mentoring (43.6%). Surgeons with less than 10 years of practice found lack of trained nursing staff (7.9% v. 4.2%, p = 0.01) and experienced assistants (12% v. 6.2%, p = 0.008) to be more important barriers than did those with over 10 years of practice, respectively. Conclusion Most general surgeons working in Ontario are self-taught with respect to MIS skills, and few perform a high volume of advanced MIS. Only one-half of all respondents have access to skilled MIS operating room nurses, surgical assistants or anesthesiology. Despite this, general surgeons perceive the greatest barriers to introducing advanced MIS procedures to be limited access to operating rooms, resources or equipment and limited mentoring. This study has shown that the role of the surgical team in advanced MIS may be underestimated by many general surgeons. These data have important implications in training general surgeons and in incorporating additional advanced MIS procedures into the armamentarium of

Barriers and facilitators to being physically active on a rural U.S. Northern Plains American Indian reservation.

PubMed

Jahns, Lisa; McDonald, Leander R; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-11-21

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual's engagement in physical activity.

Development of Self-Report Measures of Social Attitudes that Act as Environmental Barriers and Facilitators for People with Disabilities

PubMed Central

Garcia, Sofia F.; Hahn, Elizabeth A.; Magasi, Susan; Lai, Jin-Shei; Semik, Patrick; Hammel, Joy; Heinemann, Allen W.

2014-01-01

Objective To describe the development of new self-report measures of social attitudes that act as environmental facilitators or barriers to the participation of people with disabilities in society. Design A mixed methods approach included a literature review; item classification, selection and writing; cognitive interviews and field testing with participants with spinal cord injury (SCI), traumatic brain injury (TBI) or stroke; and rating scale analysis to evaluate initial psychometric properties. Setting General community. Participants Nine individuals with SCI, TBI or stroke participated in cognitive interviews; 305 community residents with those same conditions participated in field testing. Interventions None. Main Outcome Measure(s) Self-report item pool of social attitudes that act as facilitators or barriers to people with disabilities participating in society. Results An interdisciplinary team of experts classified 710 existing social environment items into content areas and wrote 32 new items. Additional qualitative item review included item refinement and winnowing of the pool prior to cognitive interviews and field testing 82 items. Field test data indicated that the pool satisfies a one-parameter item response theory measurement model and would be appropriate for development into a calibrated item bank. Conclusions Our qualitative item review process supported a social environment conceptual framework that includes both social support and social attitudes. We developed a new social attitudes self-report item pool. Calibration testing of that pool is underway with a larger sample in order to develop a social attitudes item bank for persons with disabilities. PMID:25045803

Catalyzing Cross-Disciplinary Research and Education Within and Beyond the Environmental and Geosciences to Address Emerging, Societally-Relevant Issues

NASA Astrophysics Data System (ADS)

Cak, A. D.; Vigdor, L. J.; Vorosmarty, C. J.; Giebel, B. M.; Santistevan, C.; Chasteau, C.

2017-12-01

Tackling emergent, societally-relevant problems in the environmental sciences is hardly confined to a single research discipline, but rather requires collaborations that bridge diverse domains and perspectives. While new technologies (e.g., Skype) can in theory unite otherwise geographically distributed participation in collaborative research, physical distance nevertheless raises the bar on intellectual dialogue. Such barriers may reveal perceptions of or real differences across disciplines, reflecting particular traditions in their histories and academic cultures. Individual disciplines are self-defined by their scientific, epistemologic, methodologic, or philosophical traditions (e.g., difficulties in understanding processes occurring at different scales, insufficient research funding for interdisciplinary work), or cultural and discursive hurdles (e.g., navigating a new field's jargon). Coupled with these challenges is a considerable deficiency in educating the next generation of scientists to help them develop a sufficient comfort level with thinking critically across multiple disciplinary domains and conceptual frameworks. To address these issues, the City University of New York (CUNY), the largest public urban university in the U.S., made a significant investment in advancing cross-disciplinary research and education, culminating in the opening of the CUNY Advanced Science Research Center (ASRC) in New York City (NYC) in late 2014. We report here on our experiences incubating new collaborative efforts to address environmental science-related research as it is interwoven with the ASRC's five research initiatives (Environmental Sciences, Neuroscience, Structural Biology, Photonics, and Nanoscience). We describe the ASRC's overall structure and function as both a stand-alone interdisciplinary center and one that collaborates more broadly with CUNY's network of twenty-four campuses distributed across NYC's five boroughs. We identify challenges we have faced so

Ecological bridges and barriers in pelagic ecosystems

NASA Astrophysics Data System (ADS)

Briscoe, Dana K.; Hobday, Alistair J.; Carlisle, Aaron; Scales, Kylie; Eveson, J. Paige; Arrizabalaga, Haritz; Druon, Jean Noel; Fromentin, Jean-Marc

2017-06-01

Many highly mobile species are known to use persistent pathways or corridors to move between habitat patches in which conditions are favorable for particular activities, such as breeding or foraging. In the marine realm, environmental variability can lead to the development of temporary periods of anomalous oceanographic conditions that can connect individuals to areas of habitat outside a population's usual range, or alternatively, restrict individuals from areas usually within their range, thus acting as ecological bridges or ecological barriers. These temporary features can result in novel or irregular trophic interactions and changes in population spatial dynamics, and, therefore, may have significant implications for management of marine ecosystems. Here, we provide evidence of ecological bridges and barriers in different ocean regions, drawing upon five case studies in which particular oceanographic conditions have facilitated or restricted the movements of individuals from highly migratory species. We discuss the potential population-level significance of ecological bridges and barriers, with respect to the life history characteristics of different species, and inter- and intra-population variability in habitat use. Finally, we summarize the persistence of bridge dynamics with time, our ability to monitor bridges and barriers in a changing climate, and implications for forecasting future climate-mediated ecosystem change.

BIFUNCTIONAL ALUMINUN: A PERMEABLE BARRIER MATERIAL FOR THE DEGRADATION OF MTBE

EPA Science Inventory

Bifunctional aluminum is an innovative remedial material for the treatment of gasoline oxygenates in permeable reactive barriers (PRBs). PRBs represent a promising environmental technology for remediation of groundwater contamination. Although zero-valent metals (ZVM) have been...

Barriers to and facilitators of sports participation for people with physical disabilities: a systematic review.

PubMed

Jaarsma, E A; Dijkstra, P U; Geertzen, J H B; Dekker, R

2014-12-01

Most people with physical disabilities do not participate in sports regularly, which could increase the chances of developing secondary health conditions. Therefore, knowledge about barriers to and facilitators of sports participation is needed. Barriers and facilitators for people with physical disabilities other than amputation or spinal cord injuries (SCI) are unknown. The aim of this study was to provide an overview of the literature focusing on barriers to and facilitators of sports participation for all people with various physical disabilities. Four databases were searched using MeSH terms and free texts up to April 2012. The inclusion criteria were articles focusing on people with physical disabilities, sports and barriers and/or facilitators. The exclusion criteria were articles solely focusing on people with cognitive disabilities, sensory impairments or disabilities related to a recent organ transplant or similar condition. Fifty-two articles were included in this review, with 27 focusing on people with SCI. Personal barriers were disability and health; environmental barriers were lack of facilities, transport and difficulties with accessibility. Personal facilitators were fun and health, and the environmental facilitator was social contacts. Experiencing barriers to and facilitators of sports participation depends on age and type of disability and should be considered when advising people about sports. The extent of sports participation for people with physical disabilities also increases with the selection of the most appropriate sport. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

Chakraverty, Devasmita

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

Local food in Iceland: identifying behavioral barriers to increased production and consumption

NASA Astrophysics Data System (ADS)

Ósk Halldórsdóttir, Þórhildur; Nicholas, Kimberly A.

2016-11-01

Increased production and consumption of local food may reduce the negative environmental, social, and economic impacts of industrialized and globalized food production. Here we examined potential barriers to increasing production and consumption of food produced in Iceland. First, we developed a new framework to address the behaviors of production and consumption simultaneously, to comprehensively analyze their potential barriers. We examined structural barriers by estimating the food production capacity of Iceland, and cultural and personal barriers through survey data on cultural norms and purchasing behavior from Matís, a research and development company. We found no structural barriers preventing Iceland from increasing production of local cereals, which would compliment current local production of meat and dairy and reduce reliance on imports, currently at 50% of the daily caloric intake. However, if food production became entirely local without changing the current mix of crops grown, there would be a 50% reduction in diversity (from 50 to 25 items in eight out of ten food categories). We did not identify any cultural barriers, as survey results demonstrated that consumers hold generally positive worldviews towards local food, with 88% satisfied with local food they had purchased. More than two-thirds of consumers regarded supporting the local farmer and considerations such as environmentally friendly production, fewer food miles, lower carbon footprint as important. However, they rated the local food they have access to as lower in meeting sustainability criteria, showing that they make justifications for not choosing local food in practice. This is a personal barrier to increased consumption of local food, and implies that marketing strategies and general knowledge connected to local food in Iceland might be improved. Although the results apply to the case of Iceland, the method of identifying behavioral barriers to change is applicable to other countries

JT90 thermal barrier coated vanes

NASA Technical Reports Server (NTRS)

Sheffler, K. D.; Graziani, R. A.; Sinko, G. C.

1982-01-01

The technology of plasma sprayed thermal barrier coatings applied to turbine vane platforms in modern high temperature commercial engines was advanced to the point of demonstrated feasibility for application to commercial aircraft engines. The three thermal barrier coatings refined under this program are zirconia stabilized with twenty-one percent magnesia (21% MSZ), six percent yttria (6% YSZ), and twenty percent yttria (20% YSZ). Improvement in thermal cyclic endurance by a factor of 40 times was demonstrated in rig tests. A cooling system evolved during the program which featured air impingement cooling for the vane platforms rather than film cooling. The impingement cooling system, in combination with the thermal barrier coatings, reduced platform cooling air requirements by 44% relative to the current film cooling system. Improved durability and reduced cooling air requirements were demonstrated in rig and engine endurance tests. Two engine tests were conducted, one of 1000 cycles and the other of 1500 cycles. All three coatings applied to vanes fabricated with the final cooling system configuration completed the final 1500 cycle engine endurance test. Results of this test clearly demonstrated the durability of the 6% YSZ coating which was in very good condition after the test. The 21% MSZ and 20% YSZ coatings had numerous occurrences of significant spalling in the test.

Degradation of organic pollutants and microorganisms from wastewater using different dielectric barrier discharge configurations--a critical review.

PubMed

Mouele, Emile S Massima; Tijani, Jimoh O; Fatoba, Ojo O; Petrik, Leslie F

2015-12-01

The growing global drinking water crisis requires the development of novel advanced, sustainable, and cost-effective water treatment technologies to supplement the existing conventional methods. One such technology is advanced oxidation based on dielectric barrier discharge (DBD). DBD such as single and double planar and single and double cylindrical dielectric barrier configurations have been utilized for efficient degradation of recalcitrant organic pollutants. The overall performance of the different DBD system varies and depends on several factors. Therefore, this review was compiled to give an overview of different DBD configurations vis-a-viz their applications and the in situ mechanism of generation of free reactive species for water and wastewater treatment. Our survey of the literature indicated that application of double cylindrical dielectric barrier configuration represents an ideal and viable route for achieving greater water and wastewater purification efficiency.

Environmental Chemical Assessment in Clinical Practice: Unveiling the Elephant in the Room

PubMed Central

Bijlsma, Nicole; Cohen, Marc M.

2016-01-01

A growing body of evidence suggests chemicals present in air, water, soil, food, building materials and household products are toxicants that contribute to the many chronic diseases typically seen in routine medical practice. Yet, despite calls from numerous organisations to provide clinicians with more training and awareness in environmental health, there are multiple barriers to the clinical assessment of toxic environmental exposures. Recent developments in the fields of systems biology, innovative breakthroughs in biomedical research encompassing the “-omics” fields, and advances in mobile sensing, peer-to-peer networks and big data, provide tools that future clinicians can use to assess environmental chemical exposures in their patients. There is also a need for concerted action at all levels, including actions by individual patients, clinicians, medical educators, regulators, government and non-government organisations, corporations and the wider civil society, to understand the “exposome” and minimise the extent of toxic exposures on current and future generations. Clinical environmental chemical risk assessment may provide a bridge between multiple disciplines that uses new technologies to herald in a new era in personalised medicine that unites clinicians, patients and civil society in the quest to understand and master the links between the environment and human health. PMID:26848668

Advanced system demonstration for utilization of biomass as an energy source. Environmental report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCollom, M.

1979-01-01

The conclusions and findings of extensive analyses undertaken to assess the environmental impacts and effects of the proposal to assist in an Advanced System Demonstration for Utilization of Biomass as an Energy Source by means of a wood-fueled power plant. Included are a description of the proposed project, a discussion of the existing environment that the project would affect, a summary of the project's impacts on the natural and human environments, a discussion of the project's relationships to other government policies and plans, and an extensive review of the alternatives which were considered in evaluating the proposed action. All findingsmore » of the research undertaken are discussed. More extensive presentations of the methods of analysis used to arrive at the various conclusions are available in ten topical technical appendices.« less

Furnace Cyclic Behavior of Plasma-Sprayed Zirconia-Yttria and Multi-Component Rare Earth Oxide Doped Thermal Barrier Coatings

NASA Technical Reports Server (NTRS)

Zhu, Dongming; Nesbitt, James A.; McCue, Terry R.; Barrett, Charles A.; Miller, Robert A.

2002-01-01

Ceramic thermal barrier coatings will play an increasingly important role in advanced gas turbine engines because of their ability to enable further increases in engine temperatures. However, the coating performance and durability become a major concern under the increasingly harsh thermal cycling conditions. Advanced zirconia- and hafnia-based cluster oxide thermal barrier coatings with lower thermal conductivity and improved thermal stability are being developed using a high-heat-flux laser-rig based test approach. Although the new composition coatings were not yet optimized for cyclic durability, an initial durability screening of numerous candidate coating materials was carried out using conventional furnace cyclic tests. In this paper, furnace thermal cyclic behavior of the advanced plasma-sprayed zirconia-yttria-based thermal barrier coatings that were co-doped with multi-component rare earth oxides was investigated at 1163 C using 45 min hot cycles. The ceramic coating failure mechanisms were studied by using scanning electron microscopy combined with X-ray diffraction phase analysis after the furnace tests. The coating cyclic lifetime will be discussed in relation to coating phase structures, total dopant concentrations, and other properties.

Ideal MHD Stability Prediction and Required Power for EAST Advanced Scenario

NASA Astrophysics Data System (ADS)

Chen, Junjie; Li, Guoqiang; Qian, Jinping; Liu, Zixi

2012-11-01

The Experimental Advanced Superconducting Tokamak (EAST) is the first fully superconducting tokamak with a D-shaped cross-sectional plasma presently in operation. The ideal magnetohydrodynamic (MHD) stability and required power for the EAST advanced tokamak (AT) scenario with negative central shear and double transport barrier (DTB) are investigated. With the equilibrium code TOQ and stability code GATO, the ideal MHD stability is analyzed. It is shown that a moderate ratio of edge transport barriers' (ETB) height to internal transport barriers' (ITBs) height is beneficial to ideal MHD stability. The normalized beta βN limit is about 2.20 (without wall) and 3.70 (with ideal wall). With the scaling law of energy confinement time, the required heating power for EAST AT scenario is calculated. The total heating power Pt increases as the toroidal magnetic field BT or the normalized beta βN is increased.

ENVIRONMENTAL TECHNOLOGY VERIFICATION PROGRAM - ADVANCED MONITORING SYSTEMS OUTREACH

EPA Science Inventory

Technology performance information must be effectively communicated if it is to be of value to prospective users. The U.S. Environmental Protection Agency has provided funding to the Environmental Technology Verification (ETV) program to provide a plan to verify the environmen...

Thermal Barrier Coatings (les Revetements anti-mur de chaleur)

DTIC Science & Technology

1998-04-01

blades and vanes of advanced aircraft engines », 1992, Yokohama International Gas Turbine Congress... turbine blade and nozzle guide vane aerofoils for the aerogas turbine engine . Figure 9 Scanning electron micrograph of the surface of a plasma...2. Liebert C. H. et al, "Durability of zirconia thermal barrier coatings on air cooled turbine blades in cyclic jet engine operation", NASA

Targeting therapeutics across the blood brain barrier (BBB), prerequisite towards thrombolytic therapy for cerebrovascular disorders-an overview and advancements.

PubMed

Pulicherla, K K; Verma, Mahendra Kumar

2015-04-01

Cerebral tissues possess highly selective and dynamic protection known as blood brain barrier (BBB) that regulates brain homeostasis and provides protection against invading pathogens and various chemicals including drug molecules. Such natural protection strictly monitors entry of drug molecules often required for the management of several diseases and disorders including cerebral vascular and neurological disorders. However, in recent times, the ischemic cerebrovascular disease and clinical manifestation of acute arterial thrombosis are the most common causes of mortality and morbidity worldwide. The management of cerebral Ischemia requires immediate infusion of external thrombolytic into systemic circulation and must cross the blood brain barrier. The major challenge with available thrombolytic is their poor affinity towards the blood brain barrier and cerebral tissue subsequently. In the clinical practice, a high dose of thrombolytic often prescribed to deliver drugs across the blood brain barrier which results in drug dependent toxicity leading to damage of neuronal tissues. In recent times, more emphasis was given to utilize blood brain barrier transport mechanism to deliver drugs in neuronal tissue. The blood brain barrier expresses a series of receptor on membrane became an ideal target for selective drug delivery. In this review, the author has given more emphasis molecular biology of receptor on blood brain barrier and their potential as a carrier for drug molecules to cerebral tissues. Further, the use of nanoscale design and real-time monitoring for developed therapeutic to encounter drug dependent toxicity has been reviewed in this study.

Multimodal sensing strategies for detecting transparent barriers indoors from a mobile platform

NASA Astrophysics Data System (ADS)

Acevedo, Isaiah; Kleine, R. Kaleb; Kraus, Dustan; Mascareñas, David

2015-04-01

There is currently an interest in developing mobile sensing platforms that fly indoors. The primary goal for these platforms is to be able to successfully navigate a building under various lighting and environmental conditions. There are numerous research challenges associated with this goal, one of which is the platform's ability to detect and identify the presence of transparent barriers. Transparent barriers could include windows, glass partitions, or skylights. For example, in order to successfully navigate inside of a structure, these platforms will need to sense if a space contains a transparent barrier and whether or not this space can be traversed. This project's focus has been developing a multimodal sensing system that can successfully identify such transparent barriers under various lighting conditions while aboard a mobile platform. Along with detecting transparent barriers, this sensing platform is capable of distinguishing between reflective, opaque, and transparent barriers. It will be critical for this system to be able to identify transparent barriers in real-time in order for the navigation system to maneuver accordingly. The properties associated with the interaction between various frequencies of light and transparent materials were one of the techniques leveraged to solve this problem.

Environmental Literacy of Sixth Grade Students in Arkansas: Implications for Environmental Education Reform

ERIC Educational Resources Information Center

Wood, Lisa S.

2013-01-01

Environmental education must be better integrated into K-12 curriculum to advance environmental literacy. Producing a citizenry that can understand and address the complex environmental issues facing the world today and in the future is essential to sustainable life on this planet. Using the Middle School Environmental Literacy Survey, 6th grade…

Tight junctions form a barrier in porcine hair follicles.

PubMed

Mathes, Christiane; Brandner, Johanna M; Laue, Michael; Raesch, Simon S; Hansen, Steffi; Failla, Antonio V; Vidal, Sabine; Moll, Ingrid; Schaefer, Ulrich F; Lehr, Claus-Michael

2016-02-01

Follicular penetration has gained increasing interest regarding (i) safety concerns about (environmentally born) xenobiotics available to the hair follicle (HF), e.g. nanomaterials or allergens which should not enter the skin, and (ii) the possibility for non-invasive follicular drug and antigen delivery. However, not much is known about barriers in the HF which have to be surpassed upon uptake and/or penetration into surrounding tissue. Thus, aim of this work was a detailed investigation of this follicular barrier function, as well as particle uptake into the HF of porcine skin which is often used as a model system for human skin for such purposes. We show that follicular tight junctions (TJs) form a continuous barrier from the infundibulum down to the suprabulbar region, complementary to the stratum corneum in the most exposed upper follicular region, but remaining as the only barrier in the less accessible lower follicular regions. In the bulbar region of the HF no TJ barrier was found, demonstrating the importance of freely supplying this hair-forming part with e.g. nutrients or hormones from the dermal microenvironment. Moreover, the dynamic character of the follicular TJ barrier was shown by modulating its permeability using EDTA. After applying polymeric model-nanoparticles (154 nm) to the skin, transmission electron microscopy revealed that the majority of the particles were localized in the upper part of the HF where the double-barrier is present. Only few penetrated deeper, reaching regions where TJs act as the only barrier, and no particles were observed in the bulbar, barrier-less region. Lastly, the equivalent expression and distribution of TJ proteins in human and porcine HF further supports the suitability of porcine skin as a predictive model to study the follicular penetration and further biological effects of dermally applied nanomaterials in humans. Copyright © 2016 Elsevier GmbH. All rights reserved.

The Influence of Drivers and Barriers on Urban Adaptation and Mitigation Plans—An Empirical Analysis of European Cities

PubMed Central

Reckien, Diana; Flacke, Johannes

2015-01-01

Cities are recognised as key players in global adaptation and mitigation efforts because the majority of people live in cities. However, in Europe, which is highly urbanized and one of the most advanced regions in terms of environmental policies, there is considerable diversity in the regional distribution, ambition and scope of climate change responses. This paper explores potential factors contributing to such diversity in 200 large and medium-sized cities across 11 European countries. We statistically investigate institutional, socio-economic, environmental and vulnerability characteristics of cities as potential drivers of or barriers to the development of urban climate change plans. Our results show that factors such as membership of climate networks, population size, GDP per capita and adaptive capacity act as drivers of mitigation and adaptation plans. By contrast, factors such as the unemployment rate, warmer summers, proximity to the coast and projected exposure to future climate impacts act as barriers. We see that, overall, it is predominantly large and prosperous cities that engage in climate planning, while vulnerable cities and those at risk of severe climate impacts in the future are less active. Our analysis suggests that climate change planning in European cities is not proactive, i.e. not significantly influenced by anticipated future impacts. Instead, we found that the current adaptive capacity of a city significantly relates to climate planning. Along with the need to further explore these relations, we see a need for more economic and institutional support for smaller and less resourceful cities and those at high risk from climate change impacts in the future. PMID:26317420

The Influence of Drivers and Barriers on Urban Adaptation and Mitigation Plans-An Empirical Analysis of European Cities.

PubMed

Reckien, Diana; Flacke, Johannes; Olazabal, Marta; Heidrich, Oliver

2015-01-01

Cities are recognised as key players in global adaptation and mitigation efforts because the majority of people live in cities. However, in Europe, which is highly urbanized and one of the most advanced regions in terms of environmental policies, there is considerable diversity in the regional distribution, ambition and scope of climate change responses. This paper explores potential factors contributing to such diversity in 200 large and medium-sized cities across 11 European countries. We statistically investigate institutional, socio-economic, environmental and vulnerability characteristics of cities as potential drivers of or barriers to the development of urban climate change plans. Our results show that factors such as membership of climate networks, population size, GDP per capita and adaptive capacity act as drivers of mitigation and adaptation plans. By contrast, factors such as the unemployment rate, warmer summers, proximity to the coast and projected exposure to future climate impacts act as barriers. We see that, overall, it is predominantly large and prosperous cities that engage in climate planning, while vulnerable cities and those at risk of severe climate impacts in the future are less active. Our analysis suggests that climate change planning in European cities is not proactive, i.e. not significantly influenced by anticipated future impacts. Instead, we found that the current adaptive capacity of a city significantly relates to climate planning. Along with the need to further explore these relations, we see a need for more economic and institutional support for smaller and less resourceful cities and those at high risk from climate change impacts in the future.

Self-employment as a solution for attitudinal barriers: a case study.

PubMed

Quinton, Melanie C

2014-01-01

This paper uses a case study to examine attitudinal barriers to employment and underemployment. We follow the career path of PR, a woman with multiple physical impairments, as she seeks financial independence through several employment strategies. In these, she faced attitudinal barriers and employment situations without opportunity for advancement. Eventually, PR opens her own business, turning to an alternative loan program to acquire the funds necessary to purchase a ready-made vehicle that matches her needs for accessible transportation. Use of this vehicle to provide delivery services for her business has more than doubled her income.

Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers

PubMed Central

Liu, Jian-ping; Wang, Ting-ting; Wang, Dang-ge; Dong, An-jie; Li, Ya-ping; Yu, Hai-jun

2017-01-01

The therapeutic outcome of chemotherapy is severely limited by intrinsic or acquired drug resistance, the most common causes of chemotherapy failure. In the past few decades, advancements in nanotechnology have provided alternative strategies for combating tumor drug resistance. Drug-loaded nanoparticles (NPs) have several advantages over the free drug forms, including reduced cytotoxicity, prolonged circulation in the blood and increased accumulation in tumors. Currently, however, nanoparticulate drugs have only marginally improved the overall survival rate in clinical trials because of the various pathophysiological barriers that exist in the tumor microenvironment, such as intratumoral distribution, penetration and intracellular trafficking, etc. Smart NPs with stimulus-adaptable physico-chemical properties have been extensively developed to improve the therapeutic efficacy of nanomedicine. In this review, we summarize the recent advances of employing smart NPs to treat the drug-resistant tumors by overcoming the pathophysiological barriers in the tumor microenvironment. PMID:27569390

Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers.

PubMed

Liu, Jian-Ping; Wang, Ting-Ting; Wang, Dang-Ge; Dong, An-Jie; Li, Ya-Ping; Yu, Hai-Jun

2017-01-01

The therapeutic outcome of chemotherapy is severely limited by intrinsic or acquired drug resistance, the most common causes of chemotherapy failure. In the past few decades, advancements in nanotechnology have provided alternative strategies for combating tumor drug resistance. Drug-loaded nanoparticles (NPs) have several advantages over the free drug forms, including reduced cytotoxicity, prolonged circulation in the blood and increased accumulation in tumors. Currently, however, nanoparticulate drugs have only marginally improved the overall survival rate in clinical trials because of the various pathophysiological barriers that exist in the tumor microenvironment, such as intratumoral distribution, penetration and intracellular trafficking, etc. Smart NPs with stimulus-adaptable physico-chemical properties have been extensively developed to improve the therapeutic efficacy of nanomedicine. In this review, we summarize the recent advances of employing smart NPs to treat the drug-resistant tumors by overcoming the pathophysiological barriers in the tumor microenvironment.

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

ERIC Educational Resources Information Center

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

2013-01-01

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

Barrier dysfunction and bacterial uptake in the follicle-associated epithelium of ileal Crohn's disease.

PubMed

Keita, Asa V; Söderholm, Johan D

2012-07-01

The ability to control uptake across the mucosa and protect from harmful substances in the gut lumen is defined as intestinal barrier function. The etiology of Crohn's disease is unknown, but genetic, environmental, and immunological factors all contribute. The frontline between these factors lies in the intestinal barrier. The most important inflammation-driving environmental factor in Crohn's disease is the microbiota, where Esherichia coli strains have been assigned a key role. The first observable signs of Crohn's disease are small aphtoid ulcers over Peyer's patches and lymphoid follicles. The overlaying follicle-associated epithelium (FAE) is specialized for luminal sampling and is an entry site for antigens and bacteria. We have demonstrated increased E. coli uptake across the FAE in Crohn's disease, which may initiate inflammation. This short review will discuss barrier dysfunction and bacteria in the context of ileal Crohn's disease, and how the FAE might be the site of initial inflammation. © 2012 New York Academy of Sciences.

Using opioids to treat dyspnea in advanced COPD

PubMed Central

Young, Joanne; Donahue, Margaret; Farquhar, Morag; Simpson, Cathy; Rocker, Graeme

2012-01-01

Abstract Objective To explore the experiences of family physicians and respiratory therapists in treating advanced chronic obstructive pulmonary disease (COPD) and their attitudes to the use of opioids for dyspnea in this context. Design Qualitative methodology using one-on-one semistructured interviews. Setting Southern New Brunswick (St Stephen to Sussex). Participants Ten family physicians and 8 respiratory therapists who worked in primary care settings. Methods Participant interviews were audiorecorded, transcribed verbatim, coded conceptually, and thematically analyzed using interpretive description. Main findings Participants reported that patients with advanced COPD often suffered from inadequate control of their dyspnea in advanced stages and that they saw the potential value of opioids in this context; however, family physicians described discomfort prescribing opioids. Barriers included insufficient knowledge, lack of education and guidelines, and fear of censure. Those with palliative care experience tended to be more comfortable with opioid prescribing. Conclusion Findings suggest an important need to address barriers related to more effective treatment of refractory dyspnea in advanced COPD. Further, findings indicate these efforts should focus on effective palliation and innovative educational initiatives, as well as the development, promotion, and uptake of evidence-based practice guidelines related to prescribing opioids for these patients. PMID:22798476

COST ANALYSIS OF PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF GROUND WATER

EPA Science Inventory

The U. S. Environmental Protection Agency's Office of Research and Development and its contractor have evaluated cost data from 22 sites where permeable reactive barriers (PRBs) have been utilized to remediate contaminated ground water resources. Most of the sites evaluated wer...

Environmental control and life support system requirements and technology needs for advanced manned space missions

NASA Technical Reports Server (NTRS)

Powell, Ferolyn T.; Sedej, Melaine; Lin, Chin

1987-01-01

NASA has completed an environmental control and life support system (ECLSS) technology R&D plan for advanced missions which gave attention to the drivers (crew size, mission duration, etc.) of a range of manned missions under consideration. Key planning guidelines encompassed a time horizon greater than 50 years, funding resource requirements, an evolutionary approach to goal definition, and the funding of more than one approach to satisfy a given perceived requirement. Attention was given to the ECLSS requirements of transportation and service vehicles, platforms, bases and settlements, ECLSS functions and average load requirements, unique drivers for various missions, and potentially exploitable commonalities among vehicles and habitats.

Recent advances in MoS2 nanostructured materials for energy and environmental applications - A review

NASA Astrophysics Data System (ADS)

Theerthagiri, J.; Senthil, R. A.; Senthilkumar, B.; Reddy Polu, Anji; Madhavan, J.; Ashokkumar, Muthupandian

2017-08-01

Molybdenum disulfide (MoS2), a layered transition metal dichalcogenide with an analogous structure to graphene, has attracted enormous attention worldwide owing to its use in a variety of applications such as energy storage, energy conversion, environmental remediation and sensors. MoS2 and graphene have almost similar functional properties such as high charge carrier transport, high wear resistance and good mechanical strength and friction. However, MoS2 is advantageous over graphene due to its low-cost, abundancy, tailorable morphologies and tuneable band gap with good visible light absorption properties. In this review, we have focussed mainly on recent advances in MoS2 nanostructured materials for the applications in the broad area of energy and environment. Special attention has been paid to their applications in dye-sensitized solar cells, supercapacitor, Li-ion battery, hydrogen evolution reaction, photocatalysis for the degradation of organic pollutants, chemical/bio sensors and gas sensors. Finally, the challenges to design MoS2 nanostructures suitable for energy and environmental applications are also highlighted.

Adapting Wireless Technology to Lighting Control and Environmental Sensing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dana Teasdale; Francis Rubinstein; Dave Watson

The high cost of retrofitting buildings with advanced lighting control systems is a barrier to adoption of this energy-saving technology. Wireless technology, however, offers a solution to mounting installation costs since it requires no additional wiring to implement. To demonstrate the feasibility of such a system, a prototype wirelessly-controlled advanced lighting system was designed and built. The system includes the following components: a wirelessly-controllable analog circuit module (ACM), a wirelessly-controllable electronic dimmable ballast, a T8 3-lamp fixture, an environmental multi-sensor, a current transducer, and control software. The ACM, dimmable ballast, multi-sensor, and current transducer were all integrated with SmartMesh{trademark} wirelessmore » mesh networking nodes, called motes, enabling wireless communication, sensor monitoring, and actuator control. Each mote-enabled device has a reliable communication path to the SmartMesh Manager, a single board computer that controls network functions and connects the wireless network to a PC running lighting control software. The ACM is capable of locally driving one or more standard 0-10 Volt electronic dimmable ballasts through relay control and a 0-10 Volt controllable output. The mote-integrated electronic dimmable ballast is designed to drive a standard 3-lamp T8 light fixture. The environmental multi-sensor measures occupancy, light level and temperature. The current transducer is used to measure the power consumed by the fixture. Control software was developed to implement advanced lighting algorithms, including daylight ramping, occupancy control, and demand response. Engineering prototypes of each component were fabricated and tested in a bench-scale system. Based on standard industry practices, a cost analysis was conducted. It is estimated that the installation cost of a wireless advanced lighting control system for a retrofit application is at least 30% lower than a comparable wired

Barriers and Facilitators to Being Physically Active on a Rural U.S. Northern Plains American Indian Reservation

PubMed Central

Jahns, Lisa; McDonald, Leander R.; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-01-01

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual’s engagement in physical activity. PMID:25421064

Alternative fuels and advanced technology vehicles : issues in Congress

DOT National Transportation Integrated Search

2009-02-13

Alternative fuels and advanced technology vehicles are seen by proponents as integral to improving urban air quality, decreasing dependence on foreign oil, and reducing emissions of greenhouse gases. However, major barriers especially economics curre...

Development of self-report measures of social attitudes that act as environmental barriers and facilitators for people with disabilities.

PubMed

Garcia, Sofia F; Hahn, Elizabeth A; Magasi, Susan; Lai, Jin-Shei; Semik, Patrick; Hammel, Joy; Heinemann, Allen W

2015-04-01

To describe the development of new self-report measures of social attitudes that act as environmental facilitators or barriers to the participation of people with disabilities in society. A mixed-methods approach included a literature review; item classification, selection, and writing; cognitive interviews and field testing of participants with spinal cord injury (SCI), traumatic brain injury (TBI), or stroke; and rating scale analysis to evaluate initial psychometric properties. General community. Individuals with SCI, TBI, or stroke participated in cognitive interviews (n=9); community residents with those same conditions participated in field testing (n=305). None. Self-report item pool of social attitudes that act as facilitators or barriers to people with disabilities participating in society. An interdisciplinary team of experts classified 710 existing social environment items into content areas and wrote 32 new items. Additional qualitative item review included item refinement and winnowing of the pool prior to cognitive interviews and field testing of 82 items. Field test data indicated that the pool satisfies a 1-parameter item response theory measurement model and would be appropriate for development into a calibrated item bank. Our qualitative item review process supported a social environment conceptual framework that includes both social support and social attitudes. We developed a new social attitudes self-report item pool. Calibration testing of that pool is underway with a larger sample to develop a social attitudes item bank for persons with disabilities. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Perceived barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities.

PubMed

Buffart, Laurien M; Westendorp, Tessa; van den Berg-Emons, Rita J; Stam, Henk J; Roebroeck, Marij E

2009-11-01

To explore the main barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities. Qualitative study using focus groups. Sixteen persons (12 men and 4 women) aged 22.4 (standard deviation 3.4) years, of whom 50% were wheelchair-dependent, participated in the study. Eight were diagnosed with myelomeningocele, 4 with cerebral palsy, 2 with acquired brain injury and 2 with rheumatoid arthritis. Three focus group sessions of 1.5 h were conducted using a semi-structured question route to assess perceived barriers to and facilitators of physical activity. Tape recordings were transcribed verbatim and content analysed. According to the Physical Activity for People with a Physical Disability model, barriers and facilitators were subdivided into personal factors and environmental factors. Participants reported several barriers related to attitude and motivation. In addition, lack of energy, existing injury or fear of developing injuries or complications, limited physical activity facilities, and lack of information and knowledge, appeared to be barriers to physical activity. Fun and social contacts were mentioned as facilitators of engaging in physical activity, as well as improved health and fitness. Young adults with childhood-onset physical disabilities perceived various personal and environmental factors as barriers to or facilitators of physical activity. These should be taken into account when developing interventions to promote physical activity in this population.

Assessment of the Performance Potential of Advanced Subsonic Transport Concepts for NASA's Environmentally Responsible Aviation Project

NASA Technical Reports Server (NTRS)

Nickol, Craig L.; Haller, William J.

2016-01-01

NASA's Environmentally Responsible Aviation (ERA) project has matured technologies to enable simultaneous reductions in fuel burn, noise, and nitrogen oxide (NOx) emissions for future subsonic commercial transport aircraft. The fuel burn reduction target was a 50% reduction in block fuel burn (relative to a 2005 best-in-class baseline aircraft), utilizing technologies with an estimated Technology Readiness Level (TRL) of 4-6 by 2020. Progress towards this fuel burn reduction target was measured through the conceptual design and analysis of advanced subsonic commercial transport concepts spanning vehicle size classes from regional jet (98 passengers) to very large twin aisle size (400 passengers). Both conventional tube-and-wing (T+W) concepts and unconventional (over-wing-nacelle (OWN), hybrid wing body (HWB), mid-fuselage nacelle (MFN)) concepts were developed. A set of propulsion and airframe technologies were defined and integrated onto these advanced concepts which were then sized to meet the baseline mission requirements. Block fuel burn performance was then estimated, resulting in reductions relative to the 2005 best-in-class baseline performance ranging from 39% to 49%. The advanced single-aisle and large twin aisle T+W concepts had reductions of 43% and 41%, respectively, relative to the 737-800 and 777-200LR aircraft. The single-aisle OWN concept and the large twin aisle class HWB concept had reductions of 45% and 47%, respectively. In addition to their estimated fuel burn reduction performance, these unconventional concepts have the potential to provide significant noise reductions due, in part, to engine shielding provided by the airframe. Finally, all of the advanced concepts also have the potential for significant NOx emissions reductions due to the use of advanced combustor technology. Noise and NOx emissions reduction estimates were also generated for these concepts as part of the ERA project.

Rethinking barriers: a novel conceptualization of exercise barriers in cancer survivors.

PubMed

Lee, Morgan S; Small, Brent J; Jacobsen, Paul B

2017-12-01

Previous research suggests different types of barriers may demonstrate different relationships with intention to engage in health behaviors. This study explored global, practical, and health-related barriers' relationships with exercise intention and behavior among cancer survivors. The mediating role of intention in the barriers-behavior relationships was also evaluated. Cancer survivors (N = 152) completed self-report measures of exercise barriers, intention, and behavior at baseline and of exercise behavior two months later. Global barriers were negatively related (p < .01) and practical and health-related barriers were unrelated (ps ≥ .07) to exercise intention. Global and practical barriers were negatively related (ps < .01) and health-related barriers were unrelated (p = .48) to subsequent exercise behavior. Exercise intention did not mediate any barriers-behavior relationships. Results suggest that global and practical barriers should be targeted in barriers reduction interventions and highlight the intention-behavior gap problem. Future research should explore multidimensionality of barriers for other health behaviors.

Advances in Environmental Science and Technology, Volume Two.

ERIC Educational Resources Information Center

Pitts, James N., Jr., Ed.; Metcalf, Robert L., Ed.

The aim of this volume is to help delineate and solve the multitude of environmental problems our technology has created. Representing a diversity of notable approaches to crucial environmental issues, it features eight self-contained chapters by noted scientists. Topics range from broad considerations of air pollution and specific techniques for…

Defenders and Challengers of Endothelial Barrier Function

PubMed Central

Rahimi, Nader

2017-01-01

Regulated vascular permeability is an essential feature of normal physiology and its dysfunction is associated with major human diseases ranging from cancer to inflammation and ischemic heart diseases. Integrity of endothelial cells also play a prominent role in the outcome of surgical procedures and organ transplant. Endothelial barrier function and integrity are regulated by a plethora of highly specialized transmembrane receptors, including claudin family proteins, occludin, junctional adhesion molecules (JAMs), vascular endothelial (VE)-cadherin, and the newly identified immunoglobulin (Ig) and proline-rich receptor-1 (IGPR-1) through various distinct mechanisms and signaling. On the other hand, vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2, play a central role in the destabilization of endothelial barrier function. While claudins and occludin regulate cell–cell junction via recruitment of zonula occludens (ZO), cadherins via catenin proteins, and JAMs via ZO and afadin, IGPR-1 recruits bullous pemphigoid antigen 1 [also called dystonin (DST) and SH3 protein interacting with Nck90/WISH (SH3 protein interacting with Nck)]. Endothelial barrier function is moderated by the function of transmembrane receptors and signaling events that act to defend or destabilize it. Here, I highlight recent advances that have provided new insights into endothelial barrier function and mechanisms involved. Further investigation of these mechanisms could lead to the discovery of novel therapeutic targets for human diseases associated with endothelial dysfunction. PMID:29326721